Over-clocking in a microdeposition control system to improve resolution

Cross-reference of related applications

This application was filed on June 1, 2001 under the name of "Formation of microstructure using piezoelectric deposition on a liquid substrate", US Provisional Patent Application No. 60 / 295,118 and June 1, 2001. It claims the benefits of US Provisional Patent Application No. 60 / 295,100 filed under the name "Formation of Printed Circuit Board Structures Using Liquid Circuit Board Structures", and each of these applications is related. Will be incorporated into this application.

The present invention relates to a method and system for forming a microstructure on a substrate, and more specifically to a method and system for performing piezoelectric microdeposition (PMD) of a fluid manufacturing material.

Manufacturers have developed various techniques for generating microstructures on substrates such as light emitting diode (LED) display devices, liquid crystal displays (LCD) devices, and printed circuit boards (PCBs). Many of these manufacturing techniques are relatively expensive to implement and require mass production to be economically viable.

There is a screen method as one method for forming a fine structure on a substrate. In the screen method, a fine mesh screen is placed on the substrate, and the fluid material is deposited on the substrate in the pattern shown by the screen through the screen. One problem with the screen method is that the screen and the substrate, or even the screen and the fluid material, need to be in contact with each other, which causes contamination of the substrate and the fluid material. While this technique is suitable for forming certain structures, many manufacturing processes must be carried out without contamination for the resulting structure to function. Therefore, the screen method is not a promising option for the production of certain microstructures. Microstructures that require a clean room environment and cannot tolerate contamination of substrates or fluid materials include, but are not limited to, polymer light emitting diode (PLED) displays and PCBs. ..

In recent years, it has been discovered that certain polymeric substances can be used in diodes to generate visible light of different wavelengths. Such polymers can be used to produce display devices with pixels with red, green, and blue subcomponents. PLED fluid materials are particularly desirable because they can provide a complete color display and emit a significant amount of light with very little power.

PLED display devices are expected to be used in various applications including televisions, computer monitors, PDAs, other handheld arithmetic units, mobile phones, etc. in the future. It is also expected that PLED technology will be used for environmental lighting in offices, warehouses, and living spaces.

One obstacle to the widespread use of PLED display devices is that, from experience, it is difficult to manufacture PLED display devices using conventional manufacturing techniques. For example, screen printing cannot be used to produce PLEDs because the polymers are so sensitive to contamination as mentioned above.

Photolithography is another technique used to manufacture microstructures on substrates for LED, LCD, and PCB products. The manufacturing process using photolithography generally involves depositing a photoresist material on a substrate. The photoresist material is then cured by exposure. Usually, a patterned mask is used to selectively shine light on the photoresist material, thereby curing certain parts of the photoresist layer, leaving others uncured. Next, when the uncured portion is removed from the substrate, the underlying surface of the substrate is exposed through the photoresist layer, and only the cured portion of the photoresist forms a mask and remains on the substrate. The other material is then deposited onto the substrate through an open pattern on the photoresist layer, followed by removal of the cured portion of the photoresist layer.

Photolithography has traditionally been used successfully in the manufacture of many microstructures, such as graphics on circuit boards, but this process can also contaminate the substrate and the materials formed on the substrate. Therefore, because the photoresist contaminates the manufacturing material, photolithography is incompatible with the manufacture of contact-sensitive structures such as PLED display devices and PCBs. In addition, photolithography involves multiple steps for applying and processing photoresist materials, which can be too costly and unprofitable to form relatively small amounts of structure.

Other prior art techniques such as spin coating have also been used to form other microstructures. Spin coating involves depositing a fluid material in the center of a substrate while rotating the substrate. The rotational motion of the substrate spreads the fluid material evenly over the entire surface of the substrate. However, spin coating requires additional steps because less fluid material remains on the substrate and is rather wasted during the spin coating process or removed by photolithography or laser irradiation. It can be a costly process.

<p> The present invention is to provide a microdeposition device capable of solving the problems of the prior art.</p>

<p> The microdeposition device according to the present invention A head with multiple nozzles that emit small droplets on the substrate, The stage that holds the board and Alignment means for changing the relative positions of the head and the substrate on the stage, and A camera that captures the emitted small droplets during flight to form an image, A droplet analysis means for analyzing at least one of a dropping amount, a dropping speed, a dropping nozzle position, a dropping argument, and the presence or absence of a separated droplet (satellite) from the image of the small droplet. Have<u style="single">And</u><u style="single">An error is detected based on the analysis result of the droplet analysis means, and automatically</u><u style="single">The modification of the dropping amount changes the voltage or wavelength sent to the head.</u><u style="single">The modification of the dropping speed changes the firing time and</u><u style="single">The correction of the dropping nozzle position and the dropping declination calculates the place where the dropping nozzle will actually fall and changes the positional relationship between the head and the substrate or the firing time.</u><u style="single">The correction of the separated droplet liquid changes the voltage and pulse of the head, or eliminates the filling by the automatic maintenance function.</u>It is characterized by that.</p><p> Unlike conventional manufacturing processes for forming microstructures, the PMD process of the present invention allows small droplets of fluid manufacturing material to be deposited on the substrate without contamination of the substrate or fluid manufacturing material. Therefore, the PMD process of the present invention is particularly useful when used in a clean room environment to avoid contamination, for example when manufacturing PLED display devices or PCBs.</p><p> PMD tools are usually used in the PMD method and system of the present invention. PMD tools include a nozzle assembly with a head for depositing fluid production material on a substrate and a number of independent nozzles. The PMD head is connected to a computer numerical control system for precisely depositing small droplets of fluid manufacturing material in a patterning or predetermined location on the substrate and controlling each nozzle individually. In general, PMD heads are configured to provide a high degree of precision and accuracy when used in combination with the various techniques and methods of the invention for forming microstructures on a substrate.</p><p> For precision and accuracy, the relative position between the board and the PMD head is set using the alignment component of the PMD system, which is configured to identify the reference markings on the board and align the board with the PMD head. Can be controlled. To improve the precision of the PMD system, a droplet diagnostic assembly identifies and analyzes the firing characteristics of individual nozzles and the characteristics of small droplets emitted from the nozzles. The PMD system of the present invention is specifically configured to individually control the nozzle firing characteristics and to compensate for any bias in the nozzles of the PMD head. In addition, the PMD system includes a movable stage with a vacuum chuck configured to secure and hold the substrate in a position relative to the PMD head. This stage includes plates configured to move the substrate relative to the PMD head along the X and Y axes of the XY horizontal plane. In other embodiments, the PMD head is configured to move relative to the substrate. For example, a PMD head can be mounted on a turret configured to rotate, and a linear air bearing assembly configured to move the PMD head along a horizontal plane. It can also be installed on top.</p><p> Depending on the nature of the fluid and the structures formed, some or all of the features described below can be used in combination with the basic process of depositing fluid materials with PMD heads. It has been clarified that the PMD technique of the present invention can greatly simplify the manufacturing process and reduce the cost, and for example, small-quantity manufacturing is economically feasible. The PMD systems and processes of the present invention also allow, in general, the formation of microstructures on substrates with a high degree of precision.</p><p> These and other features of the invention will become more apparent from the following description and claims and will be learned from the practice of the invention described below.</p><p> In order to further clarify the advantages and features described above and other advantages and features of the present invention, the present invention will be described in more detail with reference to the specific embodiments shown in the accompanying drawings. It will be appreciated that these drawings only show typical embodiments of the invention and should not be considered as limiting the scope of the invention. Hereinafter, the present invention will be described in more detail and in detail with reference to the accompanying drawings.</p>

<figref num="1">It is a perspective view of one Embodiment of the PMD system of this invention.</figref><figref num="2">It is a side view of the PMD system of FIG.</figref><figref num="3">It is a front view of the PMD system of FIG.</figref><figref num="4">It is the top view of the PMD system of FIG.</figref><figref num="5">FIG. 5 is a perspective view of an embodiment of a mounting bracket configured to connect a PMD head to a support of the PMD head in the PMD system of FIG.</figref><figref num="6">FIG. 5 is a side view of the mounting bracket of FIG. 5 connected to the PMD head support, which includes piping for a fluid production supply system and a solvent supply system.</figref><figref num="7">It is a side view of the mounting bracket and the PMD head of FIG. 6, and shows a state in which the PMD head is already mounted on the mounting bracket and the piping is already connected to the PMD head.</figref><figref num="8">It is a figure which shows one Embodiment of the PMD system of this invention which includes the PMD system and the computer configured to control a component.</figref><figref num="9">FIG. 7 shows the mounting bracket, PMD head, and PMD head support of FIG. 7, showing a state in which the mounting bracket and PMD head are rotated by 90 ° on the PMD head support.</figref><figref num="10">It is a diagram showing a capping station of a PMD system, including a tray, a stretchable support, and a soak reservoir.</figref><figref num="11">FIG. 5 shows a docking station configured to mount a PMD head when not in use and to store a reservoir of fluid connection material in a pressure sensitive and pressure controllable work bag.</figref><figref num="12">It is a side view of the docking station of FIG.</figref><figref num="13">It is a front view of the docking station of FIG. 11, and shows the state in which the PMD head is installed in the docking station.</figref><figref num="14">It is a figure which shows one Embodiment of the PMD head support which has a linear air bearing assembly.</figref><figref num="15">It is a figure which shows one Embodiment of the structure of the PMD system which includes a plurality of PMD head supports mounted on a linear air bearing assembly.</figref>

An object of the present invention is a piezoelectric microdeposition (PMD) that deposits a fluid material on a substrate in a controlled amount and arrangement to manufacture or manufacture a microstructure.

As used herein, the terms "fluid manufacturing material" and "fluid material" can take any form of low viscosity and are suitable for deposition on a substrate from a PMD head to form microstructures. It has a broad meaning including substances. Fluid manufacturing materials may include, but are not limited to, luminescent polymers (LEPs) that can be used to form polymer light emitting diode display devices (PLEDs, and PolyLEDs). Fluid manufacturing materials may also include plastics, metals, waxes, solders, solder pastes, biomedical products, acids, photoresist materials, solvents, adhesives, and epoxies. The term "fluid manufacturing material" is a term compatible herein with "fluid material".

As used herein, the term "deposition" generally refers to the deposition of individual small droplets of fluid material on a substrate. Also, the terms "jet," "emission," "pattern," and "deposition" are used herein as compatible terms to refer to depositing fluid material from a PMD head. The terms "small droplet" and "droplet" are also used herein as compatible terms.

As used herein, the term "substrate" has a broad meaning, including any material having a surface suitable for receiving a fluid material during a PMD process. Suitable substrate materials include, but are not limited to, glass plates, pellets, silicon wafers, ceramic tiles, rigid and flexible plastics and metal sheets and rolls. In some embodiments, the deposited fluid material itself may form a substrate because it has a suitable surface to receive the deposit of the fluid material during the PMD process. This is the case, for example, when forming a three-dimensional microstructure.

As used herein, the term "ultrastructure" generally refers to a structure that is formed with high precision and sized to fit snugly on a substrate. The term "ultrastructure" should not be construed as being limited to a particular dimension, as the dimensions of different structures are different, and may be used as a term compatible with the term "structure". .. The microstructure is a single droplet of fluid material, any combination of droplets, or a structure formed by depositing one or more droplets on a substrate, such as a two-dimensional layer, three-dimensional. Architecture, and other desirable structures.

The PMD system of the present invention performs the PMD process by depositing a fluid material on a substrate according to user-defined computer executable instructions. The term "computer-executable instructions" is also referred to herein as a "program module" or "module" and is generally a routine that implements a particular abstract data type or performs a particular task. Refers to objects, components, data structures, etc., but performing a specific task is, for example, performing computer numerical control for carrying out the PMD process of the present invention, but is not limited thereto. The program module can be stored on any computer-readable medium. A computer-readable medium can store RAM, ROM, EEROM, CD-ROM, or other optical disk storage, magnetic disk storage, or other magnetic storage, or other instructions or data structures and is general purpose. Includes, but is not limited to, computers or other media accessible by computers for special purposes.

According to the present invention, an inkjet head can form any of a variety of structures by depositing a fluid production material in a production environment and patterning the fluid production material based on the PMD process of the invention. This is under the name of PCT Patent Application No. _____, which was filed under the name of "Micro Deposition Device" on May 31, 2002, and "Temperature Control Vacuum Chuck" on May 31, 2002. PCT Patent Application No. _____ filed, PCT Patent Application No. _____ filed on May 31, 2002 under the name of "Industrial Microdeposition System for Polymer Light Emitting Diode Display, Printed Circuit Board, etc." _, PCT Patent Application No. _____ filed under the name of "Compatible Microdeposition Head Devices and Methods" on May 31, 2002, "Waveforms for Microdeposition Control Systems" on May 31, 2002. PCT Patent Application No. _____ filed under the name of "Generator", PCT Patent Application No. _____ filed under the name of "Overclocking in Microdeposition System to Increase Resolution" on May 31, 2002. It is best described in No. _ and in PCT Patent Application No. _____, which was filed on May 31, 2002 under the name "Device for Microdeposition of Multi-Fluid Materials". Each of these applications will be incorporated into this application by its relevance. According to the present invention, many structures can be manufactured more efficiently and more accurately at a lower cost than those manufactured using conventional techniques. There are also structures that can be manufactured by the PMD process but not by conventional methods. In addition, the PMD process according to the invention can be used in a clean room environment and with fluid production materials that are not contaminated during or after the production phase.

According to one embodiment, the PMD system of the present invention generally includes a stage, a vacuum chuck, a PMD head, a PMD head support, an alignment component, a fluid material supply system, a droplet diagnostic assembly, a maintenance station, a capping station. , Docking stations, and computer systems. The computer system provides the PMD system with computer-executable instructions and controls various components of the PMD system.

It is useful for the PMD tool to move relative to the substrate in order to deposit the fluid material on the substrate and / or form the microstructure. The relative movement of the PMD head and the substrate can be performed by moving the substrate and / or the PMD head. This movement may be a linear motion or a rotary motion.

For linear motion, the PMD system can be configured to use a linear motor. In one embodiment, the PMD system is configured for a clean room and has air bearings so that the linear motor does not form particles that could contaminate the clean room environment due to friction. .. The PMD system may also include HEPA filters, special bearings, motors, and assemblies that meet stringent cleanroom requirements. The mobility provided by the linear motor has the effect of allowing the PMD process to run on large substrates, such as on plastic rolls that cannot be rotated on the stage.

In some embodiments, the PMD system includes large substrates and means for rotating the PMD head to meet the requirements of certain PMD processes. Rotating the PMD head defines the pitch or angle of the nozzle with respect to the direction in which the fluid material deposits on the substrate when it is practically impossible to rotate the stage, thereby with the deposited fluid material. It is especially useful for reducing the space between and increasing the resulting resolution.

The resolution is also increased when straight lines are deposited on the substrate by rotating the PMD system and / or the substrate so that it moves in the same direction as one or more lines on which the substrate is deposited. It is possible. In this way, each droplet deposited on the substrate is deposited on the trail or tail of the previous droplet, thereby minimizing the effect of the irregularly shaped droplets. It can be reduced and the resolution of the entire side of one or more lines can be improved.

Figure 1 shows some of the components of PMD System 10. The illustrated components include a stage 12, a vacuum chuck 14, a PMD head 16, a PMD head support 18, an alignment component 20, a droplet diagnostic assembly 22, a maintenance station 24, and a capping station 26.

As shown, the stage 12 and the PMD head support 18 are mounted on a fixed surface 28. The fixed surface 28 may include any surface that is appropriately configured to provide stability to the PMD system 10 and to minimize vibrations that could compromise the precision of the PMD system 10 during use. it can. In one embodiment, the fixed surface 28 comprises a block of granite. However, it will be appreciated that the fixed surface 28 may also include other materials and structures.

2 and 3 are side views and front views of the PMD system of FIG. 1, respectively. As illustrated, the stage 12 includes an uppermost mounting plate 30 and an intermediate plate assembly 31, each configured to move in one of two different directions. As shown in FIGS. 1-3, the vacuum chuck 14, the capping station 26, the maintenance station 24, and the droplet diagnostic assembly 22 are mounted on the top mounting plate 30 of the stage 12 and thus move with the top mounting plate 30. To do.

In particular, the upper end mounting plate 30 is connected to a first motor 34 configured to drive the upper end mounting plate 30 in the first direction shown as the X axis in FIG. The intermediate plate assembly 32 and the upper end mounting plate 30 are connected to a second motor 36 configured to drive in the second direction shown as the Y axis in FIG. The first and second motors 34 and 36 can be operated independently or simultaneously to move the PMD head 16 with respect to the stage 30 in a horizontal XY plane. Therefore, it will be understood that the stage 12 can move simultaneously in both the X and Y directions of the XY planes. This mobility of the stage 12 in the XY planes is for moving the substrate mounted on the stage 12 to align with the PMD head 16 and for moving the substrate during the PMD process of the present invention. It is useful for. This will be outlined below. It will be appreciated that stage 12 is configured for a clean room environment where mobile components, especially mobile components with hard surfaces that move with each other, are generally unavailable even when placed above the substrate.

The vacuum chuck 14 provides a suitable positioning means for fixing the substrate in a fixed position on the stage 12 during the PMD process of the present invention. Other structures and methods for holding substrates, including inter-roll transfer assemblies for flexible materials, should also be considered within the scope of the invention.

The substrate 38 shown in FIG. 4 is firmly held in place on the vacuum chuck 14 by the negative pressure of air generated by sucking air through the porous metal plate 42 of the vacuum chuck 14. The porous metal plate 42 is shown in FIG. In one embodiment, the porous metal plate 42 is, for example, porous such as Metapol® sold by Portec Ltd., a subsidiary of M-Tech Holding Ltd. of Winterser. Aluminum plate. However, it is also possible to use other types of porous plates made from other materials. Air is sucked through the porous metal plate 42 by any suitable means such as a vacuum or a pump connected to the suction port 44 on the vacuum chuck 14.

The vacuum chuck 14 may also include a fitting 45. The joint 45 is configured to interconnect the devices in the vacuum chuck 14 together with the control device of the MD system 10. The fitting 45 defines, for example, a serial port through the DB9 connector, which connects the device in the vacuum chuck 14 to the control system. In one embodiment, the heating source and temperature sensor are housed in a vacuum chuck 14 and connected to a control system so that the operator can control the temperature of the porous metal plate 42.

As shown in FIG. 4, the substrate 38 is mounted on the vacuum chuck 14, but more specifically, it is mounted between the overhang supports 46 configured to align the substrate 38 on the vacuum chuck 14. .. Alignment of the substrate 38 on the vacuum chuck 14 is useful to ensure that the fluid production material is deposited in place on the substrate 38. However, it should be noted that the act of mounting the substrate 38 on the vacuum chuck 14 does not ensure that the substrate 38 is aligned with the PMD head 16 with the precise tolerances required to perform the PMD process of the present invention. I want to be. That is, the substrate 38 must be precisely aligned with the PMD head 16 according to the method of the present invention.

When the substrate 38 is mounted on the vacuum chuck 14 so as to abut against the bulge support 46, the vacuum chuck 14 is already aligned with the PMD head 16 and thus the initial alignment between the substrate 38 and the PMD head 16. Is obtained. Two reference points 48 are arranged on the vacuum chuck 14 so that the vacuum chuck 14 is reliably and precisely aligned with the PMD head 16. Any reference point 48 is engineeringly detected by the alignment component 20 as described in more detail below. The alignment component 20 usually determines that the vacuum chuck 14 is correctly aligned with the PMD head 16. If the vacuum chuck 14 is not properly aligned, move the vacuum chuck 14 until the desired alignment is obtained.

In order to properly align the vacuum chuck 14 with the substrate 38, the vacuum chuck 14 includes a step motor 52, a spring 54, and a pivot arm 56. The pivot arm 56 is connected to the step motor 52 at the first end 58 and to the spring 54 at the second end 60. The vacuum chuck 14 is also pivotally connected to the stage 12 at the pivot corner 62. This allows the vacuum chuck 14 to pivot around the pivot corner 62 when the step motor is operating.

In one embodiment, the step motor includes an extension arm 64, which can be controlledly extended to exert a force on the first end 58 of the pivot arm 56. This allows the pivot arm 56 to be pivoted around the pivot point 66 (in the top view of FIG. 4) and rotated clockwise. Since the second end 60 of the pivot arm 56 is connected to the vacuum chuck 14, this allows the vacuum chuck 14 to be pivoted around the pivot corner 62 and rotated counterclockwise. The vacuum chuck 14 can also be pivoted in the opposite direction. For example, when the arm 64 of the step motor 52 is retracted, the spring 64 is compressed, forcing the second end 60 of the pivot arm 56 towards the spring 54, thereby the vacuum chuck 14 Is pivoted around the pivot corner and rotated clockwise.

The pivot of the vacuum chuck 14 can be performed at any time to obtain the alignment of the vacuum chuck 14 or the substrate 38 with the PMD head 16. The pivot of the vacuum chuck 14 can also be performed to obtain the desired misalignment of the substrate 38 and the PMD head 16. The disengagement of the substrate 38 and the PMD head 16 may be desirable when forming some sort of microstructure on the substrate 38. In one embodiment, the desired alignment between the substrate 38 and the PMD head 16 is also with the PMD head support, eg, using a turret as described below to attach the 18 PMD head 16 to the substrate 38. It can be obtained by rotating it.

Here, the alignment component 20 will be specifically described. As illustrated in FIGS. 1 and 3, the alignment component 30 is fixedly attached to the PMD head support 18. In one embodiment, the alignment component 20 comprises a camera. The camera can be any combination of digital and optical functions, and preferably identifies a reference point 48 on the vacuum chuck 14 and a precision alignment mark formed by etching on the substrate 38. It is an optical / digital recognition module configured in. These alignment marks, which are referred to herein as origin marks, are usually preformed on the substrate 38 and are too small to be seen by the naked eye. In one embodiment, the origin mark comprises a cross as thin as vertical hair formed by etching on the substrate 38.

In one embodiment, the origin mark is used as the basis for aligning the substrate 38 with the PMD head 16. This is because alignment of the substrate 38 to the edges alone is not sufficiently accurate to form microstructures on the substrate 38 with the precision normally required to manufacture certain products. Because. For example, in one embodiment, the PMD system 10 places a small droplet of polymer on a PLED display within the range of plus or minus 10 microns, which is about one-tenth the diameter of human hair. Accumulate. It will be understood that the ability of the PMD system of the present invention to precisely deposit fluid production materials with such accuracy is an improvement of the prior art.

When the substrate 38 is mounted on the vacuum chuck 14, the PMD system 10 automatically marks the origin mark or other reference on the substrate 38 using the camera and optical recognition module associated with the alignment component 2. Identify. The vacuum chuck 14 or PMD head 16 then automatically pivots or rotates as needed to compensate for the misalignment between the PMD head 16 and the substrate 38. In this way, the alignment between the PMD head 16 and the substrate 38 is obtained within a few seconds within a tolerance of about 3 microns. Finally, once the desired alignment is obtained, the PMD system 10 will be able to precisely deposit small droplets of fluid material in a predetermined location on the substrate 38 according to the process of the present invention.

According to one embodiment, the microstructure is formed as small droplets deposited from the PMD head 16 on the substrate 38 while the substrate 38 on the stage 12 is moving below the PMD head 16. .. For example, a row of small droplets can be formed on the substrate 38 as the stage 12 moves the substrate 38 below the PMD head along the X axis. Stage 12 can be moved along the Y axis during row deposition, which allows the formation of multiple rows. The stage can also be moved along any combination of X-axis and Y-axis directions to form a variety of structures on any portion of the substrate.

The alignment of the substrate 38 with the PMD head 16 can be adjusted as described above, but if the nozzles of the PMD head 16 do not fire correctly, the alignment may be hindered. The PMD head 16 may include, for example, any number of nozzles. In one embodiment, the PMD head 16 includes a nozzle assembly (not shown) having nozzles between 1 and about 256. Even if one nozzle fails to fire, the alignment of the small droplet 38 and the PMD head 16 may fail. Therefore, it is important to identify the firing characteristics of each nozzle and correct any irregularities in firing. Once the firing characteristics of the individual nozzles are known, the computer modules of the present invention can individually control the nozzles to achieve the desired discharge of fluid material from the nozzles.

The droplet diagnostic assembly 22 shown in FIGS. 1 to 4 is arranged to measure and identify the firing characteristics of the individual nozzles of the PMD head 16. The droplet diagnostic assembly typically includes a camera 68, the camera 68, which can be any combination of digital and optical features, and preferably identifies the different firing characteristics of individual nozzles. An optical / digital recognition computer module configured to do so.

According to one embodiment, the droplet diagnostic assembly 22 captures various images of the droplet as it is ejected from the nozzle and analyzes the droplet properties of the droplet. Identify the firing characteristics of individual nozzles. If one nozzle of the PMD head does not fire correctly, the droplet diagnostic assembly and the corresponding module will detect the error. The PMD system 10 then attempts to automatically repair the nozzles using the maintenance procedure described below. If the error is not corrected automatically, the PMD system 10 alerts the operator and prevents production from being discontinued, thereby losing the expensive product of the device. The PMD head 16 can then be repaired or replaced if necessary.

According to one embodiment, the camera 68 of the droplet diagnostic assembly 20 is a right angle camera 68 configured to sit snugly on stage 12. Also, as is well known in photographic technology, a backlight such as a strobe light 69 is also provided to improve the quality of the image captured by the camera 68 and capture the image of small droplets in flight. ing. To perform the droplet diagnosis, the PMD head 16 is moved between the camera 68 and the strobe light 69 above the capping station 26. Next, a small droplet is ejected from the nozzle of the PMD head 16 into the capping station 26. Next, as described below, two right-angle images of the small droplets emitted from the nozzle are captured, and the characteristics of the droplets and the ejection characteristics of the nozzle are obtained. For maximum accuracy, it is preferred that the nozzles being tested be centered in the camera's field of view and that the nozzles be tested individually.

According to one embodiment, the first image of the first droplet is taken when the PMD head is in the first position, the PMD head is rotated 90 degrees and then fired from the same nozzle. A second image of the second small droplet is taken. In another embodiment, two right-angled cameras are used to take two images of a single droplet at the same time. Once the image of the small droplets has been captured, the PMD System 10's optical recognition module uses these images and launch information to determine the drop volume, drop rate, drop nozzle placement, drop angle deviation, and droplets. The information is calculated, thereby allowing the PMD system 10 to compensate for nozzle defects or variations in the PMD head 16.

The amount of droplets can be calculated using the height and / or width of the small droplets, or the amount can be calculated by imaging the area with one or more cameras. In either method, the image captured by the camera 68 is used to calculate or estimate the three-dimensional shape of the small droplet according to the accuracy and precision required for a particular application. If the amount of small droplets is too large or too small, the PMD system 10 adjusts the frequency with which the nozzle emits small droplets to automatically compensate. For example, the voltage or wavelength sent to the PMD head 16 can be quantitatively changed to compensate for the amount of defects dropped. If the power is reduced, smaller droplets will be emitted, and if the power is increased, larger droplets will be ejected. Even with corrections, it may be necessary to reanalyze the nozzles and corresponding droplets in an interactive process to increase control.

A second way to correct the problem related to the amount of droplets is to change the number and frequency of small droplets that deposit during the PMD process. In this method, the amount of individual droplets that drop remains the same, but the amount of fluid material that deposits on the substrate can be controlled by increasing or decreasing the frequency with which the droplets deposit. it can. This method for compensating for the drop volume problem is useful when depositing small droplets in rows or when a large number of droplets are needed to obtain the desired drop volume. This method of changing the frequency of small droplet deposition is referred to herein as fine clocking.

For example, if a state in which a fluid material is not replenished into a fluid chamber quickly enough to be jetted from a nozzle is called a starvation state, fine clocking is used to overcome the limit of deposition rate performance such as a starvation state. It is one of the means provided by the present invention. In existing printhead technology, the clock frequency of the printhead is usually limited to the maximum frequency at which printing can be performed without starvation. It will also be appreciated by those skilled in the art that this imposes practical limits on the resolution of PMD heads, especially given that multi-nozzle heads typically have only a single clock.

In order to overcome these limitations of the prior art and allow individual control of the nozzles of the PMD tool, the present invention far increases the intended deposition rate of the frequency of clock cycles or the frequency of signals sent to the PMD tool. A microclocking method is used to artificially increase the amount to exceed. The PMD system can use additional clock cycles to control the resolution and the amount of fluid material deposited during the PMD process. In one embodiment, the PMD system increases the frequency of clock cycles to 10 times the intended deposition rate, thereby placing (placeting) dots in the PMD system within one-tenth of the deposition frequency. Give the ability.

Although the deposition frequency cannot exceed the limit of starvation, it is possible to send clock cycles and data to PMD tools at fine clock progress. This is because the computer-executable instructions of the PMD system do not allow the actual deposition data to exceed the starvation rate. In this embodiment, this is done by sending "filler data" or blank data to each nozzle in about 9 out of 10 clock cycles. Therefore, the PMD tool will receive many times more data than can be used for deposition in proportion to the fine clock divided by the actual deposition clock rate. In this way, the resolution of existing printhead technology can be increased by more than 10 times without affecting the maximum deposition rate.

Fine clocking is particularly effective in increasing the resolution of the fluid material deposited on the substrate. In particular, the beginning and end of a line or shape can be controlled more precisely. In this embodiment, where the frequency of clock cycles is set to 10 times the intended deposition rate, the PMD tool allows the fluid material to be one tenth of the range of conventional resolutions possible at the same deposition rate. Within, that is, it can be deposited more than ten times more precisely than previously possible.

Fine clocking is also useful for controlling the amount of fluid material deposited on the substrate. For example, if it is desirable to deposit more fluid for the purpose of compensation for weak nozzles or simply for the purpose of increasing the thickness of the material, the corresponding nozzle will have a higher frequency of fluid material spills than other nozzles. It is set to jet the drops. For example, the specified nozzle may be set to jet jet at 1 clock out of 9 clocks, while other nozzles jet jet at 1 clock out of 10 clocks each. With this technique, the designated nozzle deposits about 11% more fluid than the other nozzles. Similarly, nozzles that deposit too much fluid can be made to deposit less frequently.

Fine clocking also provides higher resolution for placing individual dots when the PMD tool is rotating and the nozzles are not vertically aligned, when trying to accommodate differences in drip speed or declination. It is especially useful when desired and when careful control of the amount of fluid deposited on the substrate is desired.

As described above, fine clocking typically requires that the frequency of clock cycles sent to the PMD tool be higher than the intended deposition frequency. The ratio of fine clocking frequency to deposition frequency controls the potential increase in resolution. A computer-executable instruction that produces a dot pattern for jetting a fluid material must recognize a potential increase in resolution and inject zero "filler data" sent to the PMD tool for a wait cycle. Must be. The number of waiting cycles for each deposition cycle is equal to the ratio of fine clocking frequency to deposition frequency.

Fine clocking is also useful for compensating for the "pitch" of rotation of the PMD tool against substrate movement during the PMD process. PMD tool pitching provides accurate resolution to a fraction of the dots based on the ratio of fine clocking frequency to actual deposition frequency. In fine clocking, pitch is compensated by injecting "filler data" equal to the space created by shifting the angled nozzles with respect to the vertical movement of the substrate.

The dropping speed is calculated by obtaining the delay time from the nozzle firing time (Tf) and the camera strobe firing time (Ts) and obtaining the moving time TfTs = Tt. Next, an optical recognition module is used to find the moving distance (Dt), which is the distance between the center of the small droplet and the nozzle. The drip rate is finally calculated by dividing the travel distance by the travel time (Dt / Tt).

The dropping speed determines when the droplet of the fluid material hits the substrate. This is especially important when the substrate is moving. The problem with the drip rate is corrected by shifting the launch time of the small droplets to compensate for the drip rate that is too early or too slow. According to the present invention, since the dropping speed and the distance to the substrate are known, the adjustment amount regarding the launch time can be calculated. If the drip rate is too high, the launch time will be delayed, and if the drip rate is too low, the launch time will be advanced.

The placement of the droplet nozzle is determined by adjusting the illumination cycle of the strobe light 69 until the small droplets are imaged away from the nozzle. The exact location or placement of the nozzle is then identified. The correction of the irregular droplet nozzle placement is performed together with the correction of the declination of the droplet as described below.

The declination of a droplet jets a droplet of fluid material from a nozzle by a predetermined distance (this is possible because the dripping velocity is known) and then the droplet at that distance. It can be determined by identifying the center. Next, the declination is calculated using the center of the small droplet and the location of the nozzle of the droplet. In one embodiment, this is done in both the X and Y directions of the horizontal XY plane to obtain the true three-dimensional declination of the droplet.

The declination and irregular declination of the droplets is to obtain the position and declination of the nozzle placement and then actually fall to where the small droplets are expected to fall. The declination location is calculated and corrected. The launch time is then advanced or delayed to compensate for the discrepancy between the expected trajectory of the small droplet and the actual trajectory.

Droplet formation is determined by analyzing the image captured by the camera 68 with the optical recognition module to see if there is any anomalous shape outside the main droplet. This is primarily done to check if the small droplet has a significant tail or corresponding satellite. The term "satellite" as used herein generally refers to a fluid material that is emitted at the same time as a small droplet but has separated from the small droplet.

Analysis of droplet formation is a pass / failure test. If the droplets have anomalous formations or corresponding satellites, the PMD system will automatically correct the problem in one of two common methods. The first option is to change the voltage and pulse width settings of the nozzle emitting the small droplets with a computer-executable instruction from the PMD system 10. This type of correction is typically made when a new fluid material or PMD head 16 is used and the defect has spread across the entire nozzle assembly of the PMD head 16. However, if the PMD head 16 and fluid material are not new, it is likely that the PMD head nozzles are clogged or need repair. Therefore, the second option for compensating for the formation of unwanted droplets is to maintain the PMD system 10 to clear the nozzle clogging of the PMD head 16 or to repair the nozzle. If the automatic maintenance function cannot repair the nozzle, the machine will alert the user before proceeding, thereby avoiding unnecessary waste of materials and products. This is extremely important when high yields and expensive manufacturing processes are involved.

The Drop Diagnostic Assembly 22 and Alignment Component 20 of the PMD System 10 is a true innovation to existing printing technology with the accuracy gained by the Drop Diagnostic Assembly 22 and Alignment Component 20. Moreover, existing printing and patterning systems do not have the ability to measure or precisely align nozzle positions, angles, and movements with respect to substrate 38, and such systems have high yields and high costs. There is also no motivation to perform the precise alignment required for a successful manufacturing process. The development of these systems, which align the PMD head 16 and the corresponding nozzles with the substrate 38, enables the PMD process of the present invention to be manufactured with high precision.

The PMD system 10 based on the present invention makes the positioning infinitely variable, whereby uniformity can be obtained over a wide area. Further, the PMD system 10 based on the present invention controls the pitch in addition to the movement on the x and y axes. More specifically, the rotation of the PMD head 16 is useful for changing the pitch of the nozzle assembly with respect to the substrate to control the precision of the PMD process. In addition, the optical recognition and correction features provided by the PMD system 10 further enhance the controllability of droplet size. In addition, the PMD system 10 according to the present invention provides uniformity, variability, and controllability in clean applications because the PMD head 16 does not contact the substrate, but only the material deposited by the PMD head. can get.

The alignment of the PMD head 16 and the board 38 has been described as a step performed after the board is installed in the PMD system, but it is installed on the PMD head support 18 when the PMD head is replaced or not. It will be understood that alignment is always done at times. 5 to 7 are views showing a mounting bracket 70 used according to the present invention to connect the PMD head to the PMD head support 18. As shown, the mounting bracket 70 has a plurality of holes through which bolts can be threaded to secure the mounting bracket 70 to the PMD head support. Further, the protrusion bracket 70 includes a latch mechanism 74 configured to firmly hold the PMD head 16 when it is placed on the mounting bracket 70. The stake mechanism 74 generally includes a stake arm 76 configured to engage a corresponding recess formed within the PMD head 16. The latch arm 76 is operated by a lever 78 arranged on the opposite side of the mounting bracket 70 as shown in FIG. The mounting bracket 70 also includes a reference point 80 used to ensure that the PMD head is properly aligned with the mounting bracket 70 when the latch arm 75 secures the PMD head to the mounting bracket 70. ..

FIG. 7 shows an embodiment of the PMD head 16 connected to the mounting bracket 70 of FIG. As illustrated, the PMD head 16 includes a housing 90, a fluid material inlet 92, a solvent inlet 94, an internal PMD head component 96, and a nozzle assembly 98. In use, the fluid material enters the PMD head 16 through the inlet 92, is directed to the nozzle assembly 98 through the internal PMD head component 96, where it is finally discharged onto the substrate through the nozzles of the nozzle assembly 98. Will be done.

According to one embodiment, the PMD head component 96 includes a fluid material tank, a diaphragm, and a piezoelectric transducer. Piezoelectric transducers, for example, lead zirconate titanate Pb (Zr, Ti) O, which produces sound waves suitable for emitting fluid material through the nozzles of nozzle assembly 96.₃That is, it is a "PZT" transducer. The diaphragm and piezoelectric transducer generate acoustic pulses when power is supplied to the piezoelectric transducer. When the force of the acoustic pulse is sufficiently greater than the surface tension of the fluid manufacturing material, small droplets of the fluid material are ejected from the nozzles contained in the nozzle assembly 98. The velocity and amount of ejected droplets is controlled by varying the supply of power to the piezoelectric transducer.

The PMD system of the present invention can control the amount of small droplets emitted from the PMD head 16. In one embodiment, the PMD head emits small droplets of a small amount of fluid material, about 10 picolitres, at a frequency of thousands per second. Since the desired amount and frequency of small droplets will be different to accommodate the formation of different types of fluid manufacturing materials, substrates, and microstructures, the present invention presents the emission of small droplets of fluid material. It is not limited to a specific amount, frequency, and shape.

Conventional inkjet heads (jet heads) can be easily adapted for use with at least some of the fluid materials of the invention. Accordingly, the present invention also includes existing jet heads, including those manufactured or will be manufactured by third parties now or in the future and for the purpose of jetting ink in an inkjet printing system. It also includes the use of jet heads that will be produced in the future.

According to one embodiment, the PMD system 10 of the present invention comprises executing computer-executable instructions for the generation of various digital waveforms, current power supplies, and digital signals required for various printhead technologies. It includes a computer control system configured in. The computer system can be physically embedded within a separate PMD system component, or, as shown in Figure 8, the computer system is a stand-alone connected to each of the different PMD system components. It is implemented as computer system 100, which can also be configured to allow operators to control each PMD system component from a stand-alone computer system. The computer system 100 may include various control systems described herein.

One advantage of the computer system 100 is that the PMD system 10 of the present invention makes it easier and compatible to use various PMD heads 16 that have different capabilities and functionality. For example, in one embodiment, the computer system 100 separates the electronic circuits of the existing printhead technology into two different parts, a master electronic circuit part and a unique electronic circuit part. The latter can be installed inside an individual PMD head 16 or a stand-alone computer system 100.

The master electronics section is the basic signal and information for all PMD heads 18, namely the two-dimensional waveform defined by the dot pattern (deposited data) to be deposited, the slope, the duration, and the magnitude, the PMD head. The grounding and maximum voltage used in 16 and the head device accommodate the clock speed designed to deposit droplets of fluid material. Master electronics are typically stored on a computer programmable board that can make these definitions and store them for each type of PMD head 16.

The unique electronic circuitry houses certain head manufacturers and model-specific firmware. Such firmware often requires customized signals and connections. The unique electronic circuit receives customized waveforms and data from the master electronic circuit at the time of use. Personalized electronic circuits are typically stored on a computer-readable medium, such as a customized personality card. In one embodiment, a customized personality card is developed for each type of PMD head 16 used by the PMD system 10.

By defining the electronic circuit in this way, the PMD system 10 of the present invention becomes head-independent, thereby achieving compatibility between various PMD heads 16 and making the PMD system 10 various existing and existing ones. It will be possible to support newly developed technologies. In other words, it is possible to replace the PMD head 16 used by the PMD system 10 without making any hardware changes to the PMD system 10. Even piezoelectric heads of different manufacturers and different sizes, including third-party heads and heads made to deposit fluid materials other than the existing or initially fluid materials of the invention, PMDs of the invention. It can be used inside the head 16 and can be incorporated inside. This is an advance beyond the prior art, and in the prior art, the existing piezo heads were designed for a particular head technology and for one type of piezo head, which is extant. It will be understood that this limits the equipment to be updated to accommodate the new piezo head technology under development. Another advantage of defining an electronic circuit in this way is that it can individually control the nozzles of the PMD head and correct any irregularities that may exist.

Now returning to FIGS. 6 and 7, these figures show how piping 110 is used to intermanufacture the PMD head 16 with the fluid material supply system 102 and the solvent supply system 104. ing. As shown, the tubing 110 is a quick release tool configured to conveniently move tubing 100 from the PMD head 16 to the holding device 112 when not in use, eg, while the PMD head 16 is being replaced by another. 11 can be included.

6 and 7 also show how the filter 116 is connected to pipe 110 to ensure that the fluid material supplied to the PMD head 16 is clean. Although not shown, other filters may be arranged to ensure that the solvent supply to the PMD head 16 is also clean. According to the present invention, the solvent is supplied to purify the PMD head from the fluid material during the purification operation, as described in more detail below.

Next, moving to FIG. 9, the figure shows how the mounting bracket 70 can be rotated with respect to the PMD head support 18. As shown, the mounting bracket 70 is rotated 90 degrees from the positions shown in FIGS. 6 and 7. Rotation of the mounting bracket 70 is made possible by a turret 72 rotatably connected to the bottom of the PMD head support 18, according to the present invention. The rotation of the PMD head 16 is useful for facilitating the capture of right-angled images taken by the droplet diagnostic assembly as previously described. The rotation of the PMD head 16 is also useful for varying the pitch of the nozzle assembly 98 with respect to the substrate to precisely control the distance between rows of small droplets on the substrate.

FIG. 9 also shows how the reference point 80 is biased with respect to the PMD head 16 in order to ensure the alignment of the PMD head 16 in one embodiment. Reference point 80 preferably comprises hardened steel capable of accurately aligning the PMD head 16 with the mounting bracket 70. An additional reference point 120 may be placed between the top surface of the PMD head 16 and the mounting bracket 70 to further facilitate the alignment of the PMD head 16 and the mounting bracket 70. If the PMD head 16 is not properly aligned within the mounting bracket 70, the drop angles of the small droplets ejected from the nozzles may show a discrepancy, in which case the droplets as described above. The diagnostic assembly detects misalignment and compensates. However, if the misalignment is significant, it may be necessary to re-install the PMD head 16 on top of the mounting bracket 70.

Next, the capping station 26 will be described in detail with reference to FIG. As shown, the capping station 26 generally includes a tray 130 and a soak reservoir 134 mounted on a stretchable support 132. One purpose of the capping station 26 is to receive and soak the nozzles of the PMD head 16 when not in use to prevent the nozzles from drying out or clogging. For example, if the PMD head 16 is not used for a period of time, move the capping station 26 directly below the PMD head 16 and raise the tray 130 with an extendable support 132 to place the soak reservoir 134 in the PMD head 16 nozzle assembly. Engage with 98. The soak reservoir 134 is filled with a solvent that is compatible with the fluid material and prevents the nozzle assembly 98 from drying out. The solvent can be supplied to the soak reservoir 134 by other supply means such as a PMD head 16 or a pipe directly connected to a solvent supply system (not shown).

Another purpose of the capping station 26 is to capture all fluid material deposited from the PMD head 16 during droplet diagnosis. For example, the fluid material may fall onto any part of the tray 130 during droplet diagnosis. Excess fluid material or solvent that falls onto the tray 130 is processed through the drain pipe 138 connected to the tray 130.

According to one preferred embodiment, the PMD heads are compatible and can be switched manually or automatically. In one embodiment, the PMD head includes a quick connection tool, and the PMD system includes means for automatically switching PMD tools. Suitable means for automatically switching PMD heads include, but are not limited to, interfaces on the gantry and corresponding interfaces on the PMD heads. The gantry is an arm with a PMD head detachably attached to it. When the PMD head is switched to another PMD head, the PMD head is manually or automatically removed from the gantry interface and placed in the tool holder. An alternative PMD head is then manually or automatically placed over the gantry interface. Once the new PMD head is installed, the gantry is placed in the desired location for alignment, testing, and calibration of the PMD head.

As shown in FIGS. 11 to 13, the docking station 140 can also be configured to immerse the nozzle of the PMD head 16 when not in use. The docking station 140 is particularly useful when the PMD head 16 is not used for a long period of time or when the PMD head 16 is only one of the PMD heads used in the PMD system. In such cases, the unused PMD heads are housed in separate docking stations 140 to prevent the PMD head nozzles from drying out.

As shown in FIGS. 11 and 12, the docking station 140 includes a mounting bracket 142 for receiving and mounting the PMD head, a reservoir tray 144, and a soak reservoir 146. The mounting bracket 142 is configured to securely hold the PMD head 16 in place where the nozzle assembly of the PMD head 16 is placed in the soak reservoir 146 as shown in FIG. The reservoir tray 144 is configured to trap excess solvent that overflows the soak reservoir while the nozzle is immersed. Reservoir tray 144 is also configured to supplement all fluid material removed from the PMD head during the purification process described below. Thus, the reservoir tray 144 can include a drainage pipe 148 that drains all solvent and fluid material captured by the reservoir tray 144 during the purification process. The discharged fluid material and solvent can be discharged into a storage container (not shown) for ease of processing.

11 and 12 also show that the docking station 140 can be configured to hold a portion of the fluid material supply system 150. In particular, the docking station 140 includes a storage chamber 152 configured to hold the work bag 154. At the time of use, the fluid material is initially pumped into the work bag 154 and held in it until it is finally fed to the PMD head. In one embodiment, the storage chamber 152 is mounted on a weighing scale 156 configured to adjust the amount of fluid material contained in the work bag 154 at any given time. The weigh scale 156 is connected to a pump 160 configured to pump the computer module and fluid material from the fluid material supply reservoir 162 into the work bag 154. In one preferred embodiment, the two-way valve 168 controls the flow of fluid material into and out of the work bag 154.

As shown in FIGS. 11 to 13, the storage chamber 152 applies a predetermined pressure to the work bag 154 to ensure that the supply of fluid material sent from the work bag 154 to the PMD head 16 is kept constant. It is configured to include a pressure control plate 164 configured as described above. In one embodiment, this is important to prevent the PMD head from forming a meniscus in the fluid material that can potentially cause irregularities in the nozzle firing characteristics. is there. In another embodiment, the pump 160 feeds the fluid material directly to the PMD 16 and also regulates the pressure of the fluid material.

According to one embodiment, the fluid material supply system 150 typically includes a pipe 100, a work bag 154, a pump 160, and a fluid material supply reservoir 162 and varies based on the requirements of various fluid materials and printhead techniques. It can be used under various pressures. The material of the fluid material supply system 150 is preferably configured to be durable and non-reactive with the solvents used in the PMD system. For example, in one embodiment, the fluid material supply system comprises an inert lining of polytetrafluoroethylene (such as Teflon® sold by DuPont EI Denemore &amp; Co.), but other materials. Can also be used.

As mentioned above, one function of the docking station 140 is to hold the PMD head 16 while the fluid material is being ejected from the PMD head 16. Ejection may be required, for example, when a single PMD head is used to deposit a variety of different fluid materials during a single PMD process. In such cases, the PMD head is purified between different applications to prevent mixing of different fluid materials.

To perform the purification operation, the PMD head 16 is first installed on the docking station 140 as shown in FIG. The solvent is then pumped from the solvent source 104 into the PMD head 16. The solvent forces the fluid material through the PMD head until the PMD head is completely cleaned. The fluid material and solvent discharged from the PMD head 16 during this operation are discharged into the reservoir tray 144 and discharged through the drain pipe 148. Once purified, the PMD head 16 can be connected to a new source of fluid material. This purification process has been described as being performed at the docking station 140, but it will be appreciated that the purification can be performed at the capping station in much the same way.

Then returning to FIG. 1 and looking at the maintenance station 24, we see that it contains a roller assembly 170, a cushioned surface 172, and a blotting cloth 174. In use, the blotting cloth 174 is fed through the roller assembly 170 and over the cushioned surface 174. When the nozzle is clogged or fluid collects on the nozzle assembly and maintenance of the PMD head 16 is required, the maintenance station 24 is moved below the PMD head 16 and the cushioned surface 172 is the PMD head 16 It is located directly under the nozzle assembly 98 of. The cushioned surface 172 is then lifted by an elevating mechanism, eg, with a hydraulic lever assembly 176, until the blotting cloth 174 comes into contact with the nozzle assembly 98. This allows the fluid material accumulated on the nozzle assembly 98 to be sufficiently absorbed, but may need to be scraped off.

In order to perform the scraping work on the nozzle assembly 98, the nozzle assembly 98 is held against the suction cloth 174 while the suction cloth 174 is supplied from the roller assembly 170. This allows the blotting cloth 174 to frictionally engage with the nozzle assembly 98, thereby cleaning up the nozzle's undesired buildup. According to one embodiment, the blotting cloth 174 is made of a non-grindable material suitable for cleaning the nozzle without causing improper damage or abrading the nozzle. To further reduce the potential for nozzle damage, the cushioned surface 172 is configured to absorb any impact that may occur between the PMD head 16 and the maintenance station 24.

Next, refer to FIG. 14, which shows another embodiment of the present invention. As shown, the PMD head support 200 has a linear air bearing assembly 210 that is slidably mounted on a beam 220. The linear air bearing assembly 210 typically includes a linear motor with air bearings. Linear motors, known in the art, utilize magnetic coils and slugs to eliminate friction between moving parts.

The use of the linear bearing assembly 210 allows the PMD process to be carried out in a clean room environment and is beneficial in obtaining the mobility required to carry out the PMD process of the present invention on a large substrate. In particular, the mobility provided by the linear bearing assembly 210 almost eliminates the need for stage 12 to completely move each PMD component below the PMD head 16. Instead, a linear bearing assembly 210 can be used to move the PMD head 16 above the PMD components. The linear bearing assembly 210 can also move the PMD head 16 while depositing the fluid material on the substrate 38. However, in order to prevent some fluid material from rippling inside the PMD head 16, it is desirable not to move the PMD head 16 while the fluid material is being discharged from the PMD head 16. Rippling occurs when the fluid material is bounced inside the PMD head, creating irregular pressures that can affect the formation of small droplets and ejection from the nozzle.

The PMD system of the present invention has been described so far as being able to utilize only a single PMD head at a given time point. However, the PMD system of the present invention can also be configured to collaborate simultaneously using a large number of PMD heads. For example, the PMD system of the present invention can be configured as having a large number of PMD head supports, each containing a separate PMD head.

FIG. 15 shows one such embodiment. In the figure, the PMD system 300 is configured to include a multi-PMD head support 310 and a corresponding PMD head placed adjacently on a single production line. As shown, the PMD heads 320 are located below each PMD head 320 above a stage 330 configured to move in the X direction of the XY plane. Each PMD head support 310 is configured to move the PMD head in the Y direction of the XY plane.

According to this embodiment, each PMD head 320 is configured to deposit different fluid materials from different fluid material supply systems (not shown). This embodiment is particularly useful when polymers colored in different colors are deposited on a single substrate 350, such as when configuring a PLED display. For example, in one embodiment of the invention, the first PMD head is deployed to deposit a base coat and the second PMD head is deployed to deposit a red colored polymer. The third PMD head can be deployed to deposit the green colored polymer, and the fourth PMD head can be deployed to deposit the blue colored polymer. In this embodiment, the substrate 350 is sequentially moved below the different PMD heads 320 on the stage 330, so that the base coat is first deposited on the substrate 350 and then on the substrate. A red-colored polymer is deposited on the substrate, then a green-colored polymer is deposited on the substrate, and then a blue-colored polymer is deposited on the substrate.

This embodiment is also useful to eliminate the need to flush or purify the PMD head 320 over time between applications of different fluid materials. The task of purifying the PMD head 320 between applications can be extremely expensive, especially when using LEDs, as the removed fluid material can become contaminated and unusable. This embodiment is also particularly useful to allow the fluid material deposited between different applications to cure sufficiently, thereby preventing the different fluid materials from mixing and losing their distinctive and unique properties. Is.

According to another embodiment, a number of individual PMD systems are sequentially used to deposit different fluid materials on a single substrate, whereby the fluid materials are completely dried between different applications. Allows and eliminates the need to clean the corresponding PMD head.

According to yet another embodiment, a single PMD system can be used to deposit polymers colored differently by multiple PMD heads having polymers colored differently. In this embodiment, the different PMD heads. It is connected to the mounting bracket during use and to the docking station for compatibility when not in use.

According to yet another embodiment, a single PMD head can be used to deposit a wide variety of different polymeric or fluid materials. In this embodiment, the PMD head is cleaned between uses, as described above with reference to FIG.

After depositing the fluid material, it may be desirable to perform control to accelerate the curing of the fluid material or other control. One way to control the rate of cure of the fluid material after deposition is to control the temperature of the substrate. For example, the substrate can be heated by heating a porous plate with a heating element housed inside the vacuum chuck while the substrate is mounted on the vacuum chuck. Alternatively, the fluid material can be heated, for example, inside a PMD tool.

However, it will be understood that different fluid materials may have different properties and different curing rates. Accordingly, the PMD system of the present invention may also include a temperature control component configured to control a heating element housed within the vacuum chuck.

If the coefficient of thermal expansion and the temperature at which the substrate is heated are high enough, the substrate can expand or contract to the extent that the calibration and alignment process may not be performed accurately in the case of unheated substrates. forgiven. At least one of two mechanisms can be used to compensate for the swelling. First, if the coefficient of thermal expansion is known, the new position of the entire substrate can be determined based on the original position and the expected expansion or contraction. Second, the substrate can be recalibrated and aligned after heating using the alignment system described above. Both techniques are suitable, but the latter method is often more accurate because the position of the substrate is measured directly.

In summary, the invention described herein generally allows for precise microdeposition of fluid material onto a substrate. Although the examples so far have described in some detail the particular type of fluid material and the particular order in which the fluid material is deposited, the present invention presents the use of fluid materials of a particular composition and fluids in a particular order. It will be understood that it is not limited to the application of materials. Further, the examples so far may be suitable for the manufacture of PLED display devices, but the PMD system of the present invention requires the deposition of different fluid materials on LEDs, LCDs, CRTs, and substrates. It will be understood that it can also be used in the manufacture of display devices.

In other applications, the PMD process of the present invention can be used with different fluid materials to produce printed circuit board (PCB) structures including graphics, resistors, photoresists, and optical waveguides. PMD processes can also be used in biomedical industries to inspect biological, organic or synthetic fluids, products, or substances. In yet other applications, PMD systems can be used in pipettes or in glass plates with variable amounts of DNA strands, vaccines, drugs, bacteria, beers, and other biomedical products for research and development or manufacturing. It can also be used to deposit on top.

Thus, the claimed invention can be practiced in other particular embodiments without departing from its spirit and basic properties. It should be considered that the embodiments described above are for illustration purposes in all respects and are not intended to limit the invention. Therefore, the scope of the present invention is shown by the scope of claims, not the description so far. All changes that fall within the meaning and scope of the claims should be included in the claims.