Method for forming multi-layered structure, method for manufacturing wiring substrate, and method for manufacturing electronic apparatus

Multi-layer structure forming method, wiring board and manufacturing method of electronic instrument Technical field

[0001] The present invention relates to a method for forming a multilayer structure using a droplet ejection device, and more particularly to a method for forming a multilayer structure suitable for the manufacture of wiring boards and the manufacture of electronic devices.

[0002] Background Art

[0003] A method of manufacturing a wiring board and a circuit board using an additive process (Additive Process) by a printing method has attracted attention. This is because the cost of the additive process is lower than that of the method of repeating the thin film coating process and the photolithography process to manufacture the wiring board and the circuit board.

[0004] As one of the techniques using such an additive method, a technique of forming a conductive pattern by an inkjet method is known (for example, Patent Document 1).

[0005] [Patent Document 1] JP 2004-6578 No.

[0006] In the case of disposing droplets of resin materials and conductive materials using an inkjet method to form an insulating layer and a wiring pattern on the insulating layer, disconnection of the wiring pattern may occur.

[0007] Summary of the invention

[0008] In view of the above-mentioned problems, one of the objectives of the present invention is to form a stable multilayer structure using an inkjet method.

[0009] The multilayer structure forming method of the present invention uses a droplet ejection device. The method for forming the multilayer structure includes: spraying droplets of a first insulating material containing a first photosensitive resin onto the surface of an object to form a first insulating material layer covering the surface of the object (A); The step of curing the insulating material layer to obtain the first insulating layer (B); the step of spraying droplets of conductive material on the first insulating layer to form a pattern of the conductive material layer on the first insulating layer (C) And the step (D) of activating the pattern of the conductive material layer and forming a wiring pattern on the first insulating layer, further comprising: the step (E) of making the surface of the first insulating layer lyophilic; The first insulating layer and the pattern-activated conductive material layer eject droplets of a second insulating material containing a second photosensitive resin to form a layer covering the first insulating layer and the pattern-activated conductive material layer The step (F) of the second insulating material layer; and the step (G) of curing the above-mentioned second insulating material layer.

[0010] One of the effects obtained by the above configuration is that since the wiring pattern is formed after the first insulating material layer is cured, disconnection of the wiring pattern does not occur.

[0011] According to the above configuration, since the surface of the first insulating layer is lyophilized, the second insulating layer having a flat surface can be formed on the entire first insulating layer.

[0012] Preferably, the step (B) includes a step of irradiating the first insulating material layer with light of a first wavelength to cure the first insulating material layer. Furthermore, the step (E) includes a step of irradiating the surface of the first insulating layer with light of a second wavelength different from the first wavelength to make the surface of the first insulating layer lyophilic.

[0013] One of the effects obtained by the above configuration is that the curing of the first insulating material layer and the lyophilization of the first insulating layer can be achieved only by a step including light irradiation.

[0014] The method for forming a multilayer structure of the present invention uses a droplet ejection device. The method of forming the multilayer structure includes: spraying droplets of a first insulating material containing a first photosensitive resin onto the surface of an object to form a first insulating material layer covering the surface of the object (A); The step (B) of curing the insulating material layer to obtain the first insulating layer; the step (C) of making the surface of the first insulating layer lyophilic; spraying the second insulating layer containing the second photosensitive resin onto the first insulating layer

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A step of forming a second insulating material layer covering the first insulating layer with droplets of the edge material (D); and a step (E) of curing the second insulating material layer.

[0015] According to the above configuration, since the surface of the first insulating layer is lyophilized, the second insulating layer having a uniform thickness can be formed on the first insulating layer.

[0016] Preferably, the step (B) includes a step of irradiating the first insulating material layer with light of a first wavelength to cure the first insulating material layer. Furthermore, the step (C) includes a step of irradiating the surface of the first insulating layer with light of a second wavelength different from the first wavelength to make the surface of the first insulating layer lyophilic.

[0017] One of the effects obtained by the above configuration is that the curing of the first insulating material layer and the lyophilization of the first insulating layer can be achieved only by a step including light irradiation.

[0018] In addition, the present invention can be implemented in various ways. For example, the present invention can be implemented in the form of a method of manufacturing a wiring board and a method of manufacturing an electronic device.

Description of the drawings

[0019] FIG. 1 is a schematic diagram showing a liquid droplet ejection device of this embodiment.

[0020] FIGS. 2(a) and (b) are schematic diagrams showing an inkjet head in a liquid droplet ejection device.

[0021] FIG. 3 is a functional block diagram of a control unit in the liquid droplet ejection device.

[0022] FIGS. 4(a) to (d) are diagrams illustrating a method of manufacturing a wiring board of this embodiment.

[0023] FIGS. 5(a) to (c) are diagrams illustrating a method of manufacturing a wiring board of this embodiment.

[0024] FIGS. 6(a) to (d) are diagrams illustrating a method of manufacturing a wiring board of this embodiment.

[0025] FIG. 7 is a schematic diagram of the liquid crystal display device of the present embodiment.

[0026] FIG. 8 is a schematic diagram showing a mobile phone according to this embodiment.

[0027] FIG. 9 is a schematic diagram showing a personal computer according to this embodiment.

[0028] In the figure:

[0029] 7-insulating layer, 7A-first insulating material, 7B-first insulating material layer, 8-conductive layer, 8A-conductive material, 8B-conductive material layer, 9-first insulating layer, 9A- The second insulating material, 9B-the second insulating material layer, 10-wiring board, 10A-substrate, 10B-substrate, 25-semiconductor element, 32-liquid crystal panel, 34-liquid crystal display device, 1, 2, 3-liquid Droplet ejection device, 104- first position control device, 106- stage 108- second position control device, 112- control unit, 114- inkjet head, 118- nozzle, 140- light irradiation device, 500- mobile phone Machine 520-electro-optical device, 600-personal computer, 620-electro-optical device

[0030] (A. The overall structure of the droplet ejection device)

[0031] The manufacturing apparatus of this embodiment has three droplet ejection devices. The three droplet ejection devices are devices that eject the insulating material 7A (FIG. 1 ), the conductive material 8A, and the insulating material 9A, respectively. In addition, as described later, these insulating material 7A, conductive material 8A, and insulating material 9A are all one type of liquid material.

[0032] The ejection device 1 shown in FIG. 1 is a basic inkjet device. More specifically, the droplet ejection device 1 is equipped with: a container 101 holding a liquid material 111, a pipe 110, a base stand GS, a nozzle head 103, a stand 106, a first position control device 104, and a second position control device 108. The control unit 112, the illumination device 140, and the support unit 104a. Moreover, the structures and functions of the other two droplet ejection devices 2 and 3 are basically the same as those of the droplet ejection device 1. Therefore, the two droplet ejection devices 2 and 3 are omitted.

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Description of the structure and function of each droplet ejection device 2 and 3.

[0033] The ejection head 103 holds the inkjet head 114 (FIG. 2). The inkjet head 114 ejects droplets of the liquid material 111 based on a signal from the control unit 112. In addition, the inkjet head 114 in the ejection head 103 is connected to the container 101 by a pipe 110, so that the liquid material 111 can be supplied to the inkjet head 114 from the container 101.

[0034] The stage 106 provides a plane for fixing the substrate 10A. In addition, the stage 106 has a function of fixing the position of the substrate 10A with suction. Here, the substrate 10A is a flexible substrate made of polyimide, and its shape is a belt shape. In addition, both ends of the substrate 10A are fixed by a pair of rolls not shown.

[0035] The first position control device 104 is fixed to a position of a height determined by the base frame GS by the support portion 104a. The first position control device 104 has a function of moving the nozzle head 103 in the X-axis direction and the Z-axis direction perpendicular to the X-axis direction based on a signal from the control unit 112. In addition, the first position control device 104 also has a function of rotating the nozzle head 103 when rotating a shaft parallel to the Z axis. Here, in the present embodiment, the Z-axis direction is a direction parallel to the vertical direction (that is, the direction of gravitational acceleration).

[0036] The second position control device 108 moves the gantry 106 in the Y-axis direction on the base gantry GS in accordance with a signal from the control unit 112. Here, the Y-axis direction is a direction perpendicular to both the X-axis direction and the Z-axis direction.

[0037] The configuration of the first position control device 104 and the configuration of the second position control device 108 having the above-mentioned functions can be realized using a known XY automatic device using a linear motor and a servo motor. Therefore, the description of its detailed configuration is omitted here. In addition, in this specification, the first position control device 104 and the second position control device 108 are denoted as "automatic device" or "scanner".

[0038] As described above, the nozzle head 103 is moved in the X-axis direction by the first position control device 104. Furthermore, by the second position control device 108, the substrate 10A and the stage 106 move in the Y-axis direction together. As a result, the relative position of the inkjet head 114 with respect to the substrate 10A is changed. More specifically, through these actions, the ejection head 103, inkjet head 114, or nozzle 118 (FIG. 2) maintains a predetermined distance in the Z-axis direction with respect to the substrate 10A, while facing each other in the X-axis direction and the Y-axis direction. Move, that is, scan relatively. The term "relative movement" or "relative scanning" means that at least one of the side where the liquid material 111 is ejected and the side where the ejected material falls (the ejected portion) moves relative to the other.

[0039] The control unit 112 is configured to receive ejection data indicating the relative position of the droplets of the liquid material 111 to be ejected based on the external information processing device. The control unit 112 stores the received discharge data in an internal storage device, and controls the first position control device 104, the second position control device 108, and the inkjet head 114 based on the stored discharge data. In addition, the ejection data is data for applying the liquid material 111 on the substrate 10A in a predetermined pattern. In this embodiment, the ejection data has the form of bitmap data.

[0040] The droplet ejection device 1 having the above-mentioned configuration moves the nozzle 118 of the inkjet head 114 relative to the substrate 10A according to the ejection data (FIG. 2), and at the same time ejects the liquid material 11L from the nozzle 118 to the ejected portion In addition, the relative movement of the inkjet head 114 of the liquid droplet ejection device 1 and the ejection of the liquid material 111 from the inkjet head 114 are summed up and denoted as "coating scan" or "ejection scan".

[0041] In this specification, the portion where the droplet of the liquid material 111 falls is denoted as the "discharged portion". In addition, the part where the dropped droplet wets and spreads is denoted as the "coated part". Either the "discharged portion" and the "coated portion" are portions formed by performing surface modification treatment on the substrate so that the liquid material has a desired contact angle. However, the surface of the substrate without surface modification treatment has the desired lyophobicity or lyophilicity relative to the liquid material (that is, the liquid material that has fallen off has a desired contact angle on the surface of the substrate In the case of ), the surface of the substrate itself can also be the "ejected part" or the "coated part". In addition, in this book, will be "squirted

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Part" is denoted as "target" or "receiving part".

[0042] Returning to FIG. 1, the lighting device 140 is a device that irradiates the liquid material 111 provided on the substrate 10A with ultraviolet light. The on/off (ON·OFF) of the ultraviolet light irradiation of the illumination device 140 is also controlled by the control unit 112.

[0043] In addition, formation of a layer, film, or pattern by an inkjet method means that a layer, film, or pattern is formed on a predetermined object using the droplet ejection device 1 as described above.

[0044] (B. Inkjet head)

[0045] As shown in FIGS. 2(a) and (b), the inkjet head 114 in the ejection device 1 is an inkjet head having a plurality of nozzles 118. Specifically, the inkjet head 114 is equipped with a vibration plate 126 and a nozzle plate 128 that defines the opening of the nozzle 118. Furthermore, the liquid storage chamber 129 is located between the vibration plate 126 and the nozzle plate 128, and the liquid storage chamber 129 is always filled with the supplied liquid material 111 through the hole 131 from an external container (not shown).

[0046] In addition, a plurality of partition walls 122 are provided between the vibration plate 126 and the nozzle plate 128. The part enclosed by the vibration plate 126, the nozzle plate 128 and the pair of partition walls 122 is the cavity 120. Since the cavities 120 are corresponding to the nozzles 118, the number of the cavities 120 is the same as the number of the nozzles 118. The liquid material 111 is supplied from the liquid storage chamber 129 to the cavity 120 via the supply port 130 located between the pair of partition walls 122. In addition, in this embodiment, the diameter of the nozzle 118 is about 27 μm_o

[0047] In addition, respective vibrators 124 are provided on the vibration plate 126 corresponding to the respective cavities 120. Each of the vibrator 124 includes a piezoelectric element 124C and a pair of electrodes 124A and 124B that sandwich the piezoelectric element 124C. When the control unit 112 applies a driving voltage between the pair of electrodes 124A and 124B, the droplet D of the liquid material 111 is ejected from the corresponding nozzle 118. Here, the volume of the material ejected from the nozzle 118 is variable between Opl or more and 42 pl (picoliter) or less. In addition, the shape of the nozzle 118 is adjusted so that the liquid droplet D of the liquid material 111 can be ejected from the nozzle 118 in the Z-axis direction.

[0048] In this context, the part including one nozzle 118, the cavity 120 corresponding to the nozzle 118, and the vibrator 124 corresponding to the cavity 120 may also be referred to as the "discharge part 127". According to this description, one inkjet head 114 has the same number of ejection parts 127 as the number of nozzles 118. The ejection part 127 may have an electrothermal conversion element instead of the piezoelectric element. That is, the ejection portion 127 may have a configuration in which the material is ejected using the thermal expansion of the material generated by the electrothermal conversion element.

[0049] (C. Control Unit)

[0050] The configuration of the control unit 112 is described below. As shown in FIG. 3, the control unit 112 is equipped with an input buffer memory 200, a storage device 202, a processing unit 204, a light source drive unit 205, a scan drive unit 206, and an inkjet head drive unit 208. The input buffer memory 200 and the processing unit 204 are connected in a communicable manner. The processing unit 204, the storage device 202, the light source drive unit 205, the scan drive unit 206, and the inkjet head drive unit 208 are connected to each other so as to communicate with each other via a bus not shown.

[0051] The light source driving unit 205 and the lighting device 140 are communicably connected. In addition, the scanning drive unit 206 and the first position control device 104 and the second position control device 108 are connected to each other in a communicable manner. Similarly, the inkjet head driving section 208 and the inkjet head 114 are connected to communicate with each other.

[0052] The input buffer memory 200 receives ejection data for ejecting droplets of the liquid material 111 from an external information processing device (not shown) located outside the droplet ejection device 1. The input buffer memory 200 supplies the ejection data to the processing unit 204, and the processing unit 204 stores the ejection data in the storage device 202. In FIG. 3, the storage device 202 is a RAM.

[0053] The processing unit 204 provides the scan drive unit 206 with data indicating the relative position of the nozzle 118 facing the ejected portion based on the ejection data in the storage device 202. The scanning drive unit 206 compares the stage corresponding to the data and the ejection cycle

The rack drive signal is given to the first position control device 104 and the second position control device 108. As a result, the relative position of the ejection inkjet head 103 with respect to the ejected portion is changed. On the other hand, the processing unit 204 applies the ejection signal necessary for ejecting the liquid material 111 to the inkjet head 114 based on the ejection data stored in the storage device 202. As a result, the droplet D of the liquid material 111 is ejected from the corresponding nozzle 118 in the inkjet head 114.

[0054] In addition, the processing unit 204 puts the lighting device 140 in either an on state or an off state based on the discharge data in the storage device 202. Specifically, so that the light source drive unit 205 can set the state of the lighting device 140, the processing unit 204 supplies the light source drive unit 205 with respective signals indicating the on state or the off state.

[0055] The control unit 112 is a computer including a CPU, a ROM, a RAM, and a bus. Therefore, the above-mentioned functions of the control unit 112 can be realized by a software program executed by a computer. It goes without saying that the control unit 112 may also be realized by a dedicated circuit (hardware).

[0056] (D. Liquid material)

[0057] The aforementioned "liquid material 111" refers to a material having a viscosity that is ejected as liquid droplets D from the nozzle 118 of the inkjet head 114. Here, the liquid material 111 may be water-based or oily. It is sufficient if it is a liquid material having fluidity (viscosity) that can be ejected from the nozzle 118, and even if a solid substance is mixed in, it may be a fluid as a whole. Here, it is preferable that the viscosity of the liquid material 111 is ImPa·S or more and 50 mPa·s or less. When the viscosity is ImPa·s or more, when the droplets D of the liquid material 111 are ejected, the periphery of the nozzle 118 is unlikely to be contaminated by the liquid material 111. On the other hand, when the viscosity is 50 mPa·s or less, the hole clogging frequency of the nozzle 118 is low, and therefore, the ejection of the droplet D can be smoothly achieved.

[0058] The conductive material 8A (FIG. 4(d)) described later is one of the above-mentioned liquid materials 111. The conductive material 8A of the present embodiment contains silver particles having an average particle diameter of about 10 nm and a dispersant. Furthermore, in the conductive material 8A, the silver particles are stably dispersed in the dispersant. In addition, the silver particles may be coated with a coating agent. Here, the so-called coating agent is a compound that can coordinate with silver atoms.

[0059] As such coating agents, amines, alcohols, mercaptans, and the like are well known. More specifically, as the coating agent, amine compounds such as 2-methylaminoethanol, diethanolamine, diethylmethylamine, 2-dimethylaminoethanol, methyldiethanolamine, and alkylamines can be used. , Ethylenediamine, Alkyl Alcohols, Diethylene Glycol, Propylene Glycol, Alkyl Mercaptans, Ethylene Dithiol.

[0060] The dispersant (or solvent) is not particularly limited as long as it is capable of dispersing conductive fine particles such as silver nanoparticles and does not cause aggregation. For example, in addition to water, alcohols such as methanol, ethanol, propanol, butanol, n-heptane, n-octane, decane, dodecane, tetradecane, toluene, xylene, and isopropyl toluene can be exemplified. , Duene, seedling, dipentene, tetrahydronaphthalene, decahydronaphthalene, cyclohexylbenzene and other green compounds, or ethylene glycol dimethyl alcohol, ethylene glycol diethyl alcohol, ethylene glycol methyl ethyl Brew, Diethylene Glycol Dimethyl, Diethylene Glycol Diethyl Brew, Diethylene Glycol Methyl Ethyl Brew, 1,2-Dimethoxyethane, Bis(2-Methoxyethyl) Brew, Diethylene Glycol Diethyl Brew, Diethylene Glycol Dimethyl Oxane and other brewing compounds, as well as the polarity of propylene carbonate, Y-butyrolactone, N-methyl-2-pyrrolidone, dimethylformamide, dimethyl pyridine, cyclohexanone, etc. Compound. Among them, from the viewpoint of the dispersibility of conductive fine particles and the stability of the dispersion liquid and the ease of application to the droplet ejection method, water, alcohols, green compounds, and brewing compounds are preferable, and more preferable dispersants include Effluent and blank compounds.

[0061] In addition, particles with an average particle diameter of about 1 nm to several 100 nm are denoted as "nanoparticles". According to this description, the conductive material 8A contains silver nanoparticles.

[0062] In addition, the insulating material 7A (FIG. 4) and the insulating material 9A (FIG. 6) described later are both the liquid material 111. The insulating material 7A and the insulating material 9A contain photosensitive resin. Furthermore, the photosensitive resin of this embodiment contains a photoinitiator and acrylic monomers and/or oligomers. The acrylic photosensitive resin of this embodiment is compatible with the "first photosensitive resin of the present invention".

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"Positive resin" and "second photosensitive resin" correspond to each other. Thus, in this embodiment, "first photosensitive resin" and "second photosensitive resin" are the same as each other.

[0063] Hereinafter, a method of manufacturing a wiring board using the method of forming a multilayer structure of the present embodiment will be described.

[0064] (Ε. Manufacturing method)

[0065] First, UV cleans one surface S of the substrate 10A. UV washing not only cleans the surface S, but also makes the surface S suitable lyophilic with respect to the liquid insulating material 7A described later. Therefore, in this embodiment, the surface S after UV washing becomes the part to be ejected and the part to be coated as described above. In addition, in this embodiment, the surface S is an example of the "object surface" of the present invention.

[0066] Then, as shown in FIG. 4(a), an insulating material layer 7B is formed on the entire surface S using the droplet ejection device 1. Specifically, first, the position of the substrate 10A on the stage 106 of the droplet ejection device 1 is determined. In doing so, the relative position of the droplet ejection device 1 with respect to the nozzle 118 of the surface S is changed in two dimensions (that is, the X-axis direction and the Y-axis direction). Then, the droplet ejection device 1 ejects the droplets D of the liquid insulating material 7A from the nozzle 118 to the surface S at a predetermined cycle based on the first ejection data. In doing so, a plurality of droplets D bounce down and wet and spread across the entire surface S at a predetermined interval. In addition, when the multiple droplets D that have fallen are wetted and spread, an insulating material layer 7B covering the surface S is obtained. In addition, the volume and number of droplets D of the insulating material 7A to be ejected are set so that the thickness of the insulating layer 7 (FIG. 4( c )) obtained after the curing step described later becomes about 10 μm.

[0067] Here, the nozzle 118 in the inkjet head 114 of the liquid droplet ejection device 1 is denoted as a "first nozzle".

[0068] In the present embodiment, the substrate 10A and one or more layers provided on the substrate 10A are collectively referred to as "base 10B".

[0069] After the insulating material layer 7B is formed, as shown in FIGS. 4(b) and (c), the obtained insulating material layer 7B is cured to form the insulating layer 7. Specifically, the light having the first wavelength belonging to the ultraviolet region is irradiated with the insulating material layer 7B for about 60 seconds (sec) by the illuminating device 140, and the insulating layer 7 is obtained. In this embodiment, the wavelength of the light irradiating the insulating material layer 7B is 365 nm_o

[0070] In this way, since the insulating material layer 7B serving as the base is cured before the pattern of the conductive material layer 8B described later (FIG. 4(d)) is formed, the pattern of the conductive material layer 8B does not break.

[0071] Then, as shown in FIG. 4(d), the conductive material layer 8B is patterned on the insulating layer 7 using the droplet ejection device 2. Specifically, first, the position of the substrate 10A on the stage 106 of the droplet ejection device 2 is determined. In doing so, the relative position of the droplet ejection device 2 relative to the nozzle 118 on the surface of the insulating layer 7 is changed in two dimensions (that is, the X-axis direction and the Y-axis direction). Furthermore, the droplet ejection device 2 ejects the liquid conductive material 8A from the nozzle 118 to the surface of the insulating layer 7 every time the nozzle 118 reaches a position corresponding to the pattern of the conductive material layer 8B based on the second ejection data. Droplet D. In doing so, a plurality of droplets D bounce off the insulating layer 7 and wet and expand. Then, when the plurality of droplets D that fall and spread wet and spread, a pattern of the conductive material layer 8B is formed on the insulating layer 7. In addition, the volume and number of droplets D of the conductive material 8A to be ejected are set so that the thickness of the conductive layer 8 (FIG. 5(b)) obtained after the heating process described later becomes about 4 um.

[0072] Here, the nozzle 118 in the inkjet head 114 of the droplet ejection device 2 is denoted as a "second nozzle".

[0073] In addition, in the present embodiment, as shown in FIG. 5(a), the pattern of the conductive material layer 8B includes two strip-shaped portions parallel to each other. The two strips are respectively located on a part of the insulating layer 7. In addition, the width of the two band-shaped portions is about 50 μm, and the length direction thereof extends in a direction perpendicular to the paper surface of FIG. 5(a).

[0074] Then, the pattern of the conductive material layer 8B as shown in FIG. 5(a) is activated to form the pattern of the conductive layer 8 as shown in FIG. 5(b). Specifically, using a clean heater at a temperature of 150 ° C to make the conductive material layer 8B

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The pattern is fired (heated) for 30 minutes (min). In doing so, the silver particles in the conductive material layer 8B are sintered or thermally bonded, and the pattern of the conductive layer 8 is obtained. Here, the pattern of the conductive layer 8 corresponds to the "wiring pattern" of the present invention. In addition, in this specification, the pattern of the conductive layer 8 is expressed as "conductive pattern".

[0075] In this way, before providing the insulating material layer 9B (described later) covering the insulating layer 7 and the wiring pattern in this embodiment, the conductive material layer 8B is fired in advance to form the conductive layer 8. In doing so, the resulting conductive layer 8 is less likely to be deformed by the stress generated by the curing of the insulating material layer 9B. This is because the adhesive force between the insulating layer 7 and the conductive layer 8 is stronger than the adhesive force between the insulating layer 7 and the conductive material layer 8B (the conductive layer 8 before being activated).

[0076] After the wiring pattern (the pattern of the conductive layer 8) is formed, as shown in FIG. 5(c), the surface of the insulating layer 7 and the surface of the wiring pattern are lyophilized. Specifically, the surface of the insulating layer 7 and the surface of the conductive layer 8 are uniformly irradiated with light of a second wavelength different from the above-mentioned first wavelength for about 60 seconds. In this embodiment, the second wavelength is 172 nm. In doing so, the surface of the insulating layer 7 and the surface of the wiring pattern are lyophilic with respect to the liquid insulating material 9A (FIG. 6(a)) described later. Here, one of the indexes indicating the degree of lyophilicity is "contact angle". In this embodiment, when a droplet of the insulating material 9A is in contact with the surface of the lyophilized insulating layer 7 or the surface of the wiring pattern, the contact angle formed by the surface and the droplet D is 20 degrees or less.

[0077] The reason for making the surface of the insulating layer 7 and the surface of the wiring pattern lyophilic is as follows. After the curing step for obtaining the insulating layer 7 or the firing (heating) step for obtaining the wiring pattern, the surface thereof is liquid-repellent with respect to the liquid insulating material 9A. Here, when the surface of the object is lyophobic, it is difficult to form a uniform layer over a wide area. In contrast, in the present embodiment, since the surface of the insulating layer 7 and the surface of the wiring pattern are lyophilized after the firing step, the insulating material 9A is formed on the surface of the insulating layer 7 and the surface of the wiring pattern 25. The degree of droplet wetting and spreading (the degree of lyophilicity) increases again. Therefore, the insulating layer 9 having a flat surface can be formed on the entire surface thereof. Moreover, the thickness of the insulating layer 9 is uniform on the insulating layer 7 and on the wiring pattern, respectively.

[0078] After the above-mentioned lyophilization is performed, as shown in FIG. 6(a), an insulating material layer 9B covering the pattern of the insulating layer 7 and the conductive layer 8 is formed by the droplet ejection device 3. Specifically, the substrate 10A is positioned on the stage 106 of the droplet ejection device 3. In doing so, the relative position of the droplet ejection device 3 with respect to the nozzle 118 of the pattern of the insulating layer 7 and the insulating layer 8 is changed two-dimensionally. In addition, the droplet ejection device 3 ejects liquid droplets Do of the insulating material 9A from the nozzle 118 to the pattern of the insulating layer 7 and the conductive layer 8 at a predetermined cycle based on the third ejection data. The drop D bounces and wets and expands in the entire area of the pattern of the insulating layer 7 and the conductive layer 8 at a predetermined interval. In addition, when the plurality of droplets D that fall and spread wet and spread, the insulating material layer 9B covering the pattern of the insulating layer 7 and the conductive layer 8 is obtained. In addition, the volume and the number of droplets D of the insulating material 9A to be ejected are set so that the thickness of the insulating layer 9 (FIG. 6( d)) obtained after the heating process described later becomes about 10 μm.

[0079] Here, the nozzle 118 in the inkjet head 114 of the liquid droplet ejection device 3 is denoted as a "third nozzle".

[0080] After the insulating material layer 9B is formed, as shown in FIG. 6(b), the obtained insulating material layer 9B is semi-cured to form the insulating material layer 9B. Specifically, the illuminating device 140 irradiates the insulating material layer 9B with light having a wavelength in the ultraviolet region for about 4 seconds to obtain the insulating material layer 9B in a semi-cured state. In this embodiment, the wavelength of the light irradiating the insulating material layer 9B is 365 nm.

[0081] Here, the term "semi-curing the insulating material layer or the insulating material" refers to a state between the state when the photosensitive resin constituting the insulating material layer is discharged and the actual cured state caused by light irradiation. In this embodiment, such an intermediate state is the aforementioned "semi-cured state". In addition, the state at the time of ejection is a state where the photosensitive resin (insulating material 7A) is ejected from the nozzle 118 and has viscosity.

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[0082] In addition, the time for irradiating the insulating material layer 9B with light may be longer (for example, 60 seconds) to actually cure the insulating layer 9B instead of the semi-curing of the insulating material layer 9B.

[0083] The insulating material layer 9B in a semi-cured state is obtained, and then, as shown in FIG. 6(c), the base 10B is heated to give heat Q. In this embodiment, a cleaning dryer is used to heat the base 10B at a temperature of 150° C. for 60 minutes. By such heating, the polymerization reaction of the photosensitive resin in the insulating material layer 9B is further promoted, and the insulating material layer 9B is cured. As a result, the insulating material layer 9B becomes the insulating layer 9. In addition, when the insulating material layer 9B is cured by light irradiation, it is preferable to perform such a heating step.

[0084] Here, even in the case where monomers and oligomers with incomplete polymerization reaction are present in the insulating layer 7 formed first, the heating process for curing the insulating material layer 9B' can also make the insulating layer 7 The polymerization reaction ended surely. Similarly, since the sintering or thermal bonding of the silver nanoparticles in the conductive layer 8 can be completely performed by this heating process, the electrical conduction in the conductive layer 8 becomes more reliable.

[0085] Through the above steps, as shown in FIG. 6(d), an insulating layer 7 covering the substrate 10A, a pattern of the conductive layer 8 on the insulating layer 7, and a pattern covering the insulating layer 7 and the conductive layer 8 are obtained. Layer 9 constitutes a multilayer structure. In this embodiment, the insulating layer 7 and the insulating layer 9 are acrylic resin, and the conductive layer 8 is silver wiring. In addition, the substrate 10A provided with the conductive layer 8 is referred to as "wiring substrate 10".

[0086] (F. Mounting process)

[0087] Hereinafter, as shown in FIG. 7, the liquid crystal panel 32 and the semiconductor element 25 are mounted on the wiring board 10. Specifically, a part of the pattern of the conductive layer 8 that is not covered by the insulating layer 9 is formed on a part of the wiring substrate 10. Then, the base of the liquid crystal panel or the base corresponding to the semiconductor element 25 is joined to the pattern of the exposed conductive layer 8. In this way, the liquid crystal display device 34 is obtained. In this way, the manufacturing method of the present embodiment can be applied to the manufacturing of the liquid crystal display device 34. In addition, in this embodiment, the semiconductor element 25 is a liquid crystal drive circuit.

[0088] In addition, the manufacturing method of the present embodiment is not only applicable to the manufacture of liquid crystal display devices, but also applicable to the manufacture of various electro-optical devices. Here, the "electro-optical device" is not limited to devices that use changes in optical characteristics (so-called electro-optical effects) such as changes in birefringence, changes in optical rotation, and changes in light diffusivity. A full-scale device for passing or reflecting.

[0089] Specifically, the electro-optical device includes a liquid crystal display device, an electroluminescence display device, a plasma display device, and a display device using surface conduction electron emission elements (SED: Surface-Conduct ion Electron-Emitter Display)> Field Emission display device (FED: Field Emission Display) and other terms.

[0090] In addition, the multilayer structure forming method of this embodiment can be applied to various manufacturing methods of electronic devices. For example, the manufacturing method of the mobile phone 500 including the electro-optical device 520 shown in FIG. 8 and the manufacturing method of the personal computer 600 including the electro-optical device 620 shown in FIG. 9 are both applicable to the manufacturing method of this embodiment.

[0091] (Modification 1)

[0092] According to the above-mentioned embodiment, the three different droplet ejection devices 1, 2, and 3 eject the insulating material 7A, the conductive material 8A, and the insulating material 9A, respectively. Instead of such a configuration, a single droplet ejection device (for example, the droplet ejection device 1) can eject the aforementioned insulating material 7A, conductive material 8A, and insulating material 9A, which are necessary. At this time, the insulating material 7A, the conductive material 8A, and the insulating material 9A may be ejected from the respective nozzles 118 in the droplet ejection device 1, or may be ejected from one nozzle 118 in the droplet ejection device 1. Squirting out. When three types of liquid materials are ejected from one nozzle 118, when replacing the liquid materials, it is only necessary to increase the process of washing the path from the container 101 to the nozzle 118.

[0093] Here, when three types of liquid materials are ejected from one nozzle, the so-called "first nozzle" and "second nozzle" are

CN 1753600 Β

"Nozzle" and "3rd nozzle" correspond to the same nozzle 118.

[0094] (Modification 2)

[0095] In the above-mentioned embodiment, a multilayer structure is provided on a substrate 10A made of polyimide. However, even if a ceramic substrate, a glass substrate, an epoxy resin substrate, a glass epoxy resin substrate, and a silicon substrate are used instead of such a substrate 10A, the same effects as those described in the above-mentioned embodiment can be obtained.

[0096] (Modification 3)

[0097] The conductive material 8A of the above embodiment contains silver nanoparticles. However, it is also possible to use other metal nanoparticles instead of silver nanoparticles. Here, as other metals, for example, any one of gold, platinum, copper, rake, cobalt, copper, nail, iron, iron, tin, zinc, diamond, nickel, luo, titanium, tongs, duck, and chuck can be used, or Any two or more alloys in combination can also be used. However, in the case of silver, since it can be reduced at a relatively low temperature and is easy to handle, from this point of view, in the case of using a droplet ejection device, it is preferable to use the conductive material 8A containing silver-containing nanoparticles.

[0098] In addition, the conductive material 8A may contain an organometallic compound instead of metal nanoparticles. Here, the term "organometallic compound" refers to a compound that can precipitate a metal by decomposition by heating. Such organometallic compounds include chlorotriethyl phosphonium (I), chlorotrimethyl phosphonium (D, chlorotriphenyl phosphonium (D, silver (D2,4-pentyl mercaptan coordination compound, trimethyl) Lin (hexafluoroacetylacetonate) silver (I) coordination compound, copper (I) hexafluoropentanediol cyclooctadiene coordination compound, etc.

[0099] In this way, the form of the metal contained in the liquid conductive material 8A may be in the form of particles represented by nanoparticles or in the form of compounds such as organometallic compounds.

[0100] In addition, the conductive material 8A may contain a polymer-based soluble material such as polyaniline, polyphene, polyphenylene vinylene, etc., instead of metal.

[0101] (Modification 4)

[0102] In the above embodiment, the insulating layer 7 and the insulating layer 9 are made of the same material as each other. However, the insulating layer 7 and the insulating layer 9 may be made of materials different from each other. For example, the insulating layer 7 is acrylic resin, and the insulating layer 9 may also be polyimide resin. In this case, the insulating material 7A may be a liquid material containing a monomer or oligomer of a photosensitive acrylic resin, and the insulating material 9A may be a liquid material containing a photosensitive polyimide precursor. That is, in this case, the "first photosensitive resin" and the "second photosensitive resin" of the present invention are different from each other.

[0103] (Modification 5)

[0104] According to the above-described embodiment, the pattern of the conductive layer 8 is formed on the insulating layer 7. However, the multilayer structure forming method of the above-mentioned embodiment does not apply to the formation of such a structure. Specifically, the pattern of the conductive layer 8 on the insulating layer 7 may also be omitted. Furthermore, it is also possible to repeat the following operations so that the total thickness of a plurality of laminated insulating layers becomes a desired value: forming an insulating material layer with a droplet ejection device, curing the formed insulating material layer to obtain an insulating layer, and making the insulating layer The surface is lyophilized, and an insulating material layer is formed on the lyophilized insulating layer with a droplet ejection device.

[0105] From the point of view of the insulating material layer formed by spraying, the method of forming an insulating layer of a desired thickness by repeating the formation of the insulating material layer, lyophilization and curing process is the same as obtaining the insulating layer of the desired thickness by a single curing process. Compared with this, the total drying time is short, and the thickness of the final insulating layer is easy to be uniform.

[0106] (Modification 6)

[0107] According to the above-described embodiment, irradiating light of a wavelength in the ultraviolet region makes the surface of the insulating layer 7 and the surface of the wiring pattern lyophilic. However, in the atmosphere, oxygen is used as the processing gas.₂Instead of such lyophilization, plasma treatment may lyophilize the surface of the insulating layer 7 and the surface of the wiring pattern. Ο? Plasma treatment is performed by plasma (not shown)

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The sub-discharge electrode irradiates the substrate 10A (base 10B) with oxygen in a plasma state. . 2 plasma treatment conditions as long as the plasma power is 50~1000W, the oxygen flow rate is 50~100mL/min, the relative moving speed of the substrate 10 with respect to the plasma discharge electrode is 0.5~10mm/sec, and the substrate temperature is 70 ~90°C is sufficient.

CN 1753600 Β