Optoelectronic converter and process of manufacturing

p0001The invention relates to an optoelectronic converter with a radiation-emitting and / or receiving body, which is mounted on a carrier unit. It particularly relates to such a photoelectric converter, wherein the radiation-emitting and / or receiving body, a correspondingly formed semiconductor chip or a polymer luminescent or -Laserdiode is.

p0002Such optoelectronic transducer is known for example from the European patent EP 4 12 184 B1 and shown in Figure 12th In this known optoelectronic transducer is a radiation detector assembly comprising a detector device 39, for example a photo diode, a common carrier 33, an insulator 34, a mounting member 35, a lens holder 36 and a lens 37 for focusing the received by the detector device 39 radiation , The detector device 39 is fixed with its underside to the insulator 34, which in turn is attached to the common carrier 33rd The fixing member 35 is disposed adjacent to the insulating body 34 on the common carrier 33rd On the mounting portion 35 of the lens carrier 36 is fixed with the lens 37, such that the lens 37 is over the beam entrance surface 40 of the detector device 39 by means of a fixing layer 38th

p0003The assembly of the individual components of such optoelectronic transducer is very expensive. It requires a large number of process steps and the adjustment of the lens 37 is very difficult. In addition, generally occur due to the air gap between the lens 37 and the detector device at 39 large reflection losses and aberrations within the transducer.

p0004Furthermore, from the German Offenlegungsschrift DE 43 23 681 an optoelectronic transducer, in which a deflection mirror and a plane parallel to the support longitudinal axis of the optical fiber are arranged on one side of a light-transmitting support, an optical receiving or transmitting element and on the other side of the carrier. The example of an optical transmission element emitted light passes through the common carrier, is deflected at the deflection mirror by 90 ° in the direction of the optical fiber and coupled into this. In case of a receiving element through the optical fiber, the incoming light signal is deflected at the deflection mirror by 90 ° in the direction receiving element, then passes through the common carrier and is coupled into the receiving element.

p0005The production of this previously known arrangement requires high installation and adjustment. Conventional methods for mounting semiconductor devices on a printed circuit board can not be used in this arrangement.

p0006The invention is therefore based on the object to develop an optoelectronic converter of the aforementioned type, which can be mounted with conventional methods of component mounting, insbesondnere for surface mounting is suitable, that is in SMD (Surface mounted device) can be mounted on a circuit board.

p0007At the same time these optoelectronic transducer is easy to manufacture in large quantities and over other optical devices can be exactly adjusted easily and have a high efficiency of light extraction.

p0008This object is achieved by an optoelectronic converter having the features of claim 1.

p0009Advantageous developments of the invention are subject of subclaims 2 to 10. Preferred methods for fabricating a plurality of optoelectronic transducers according to the invention are subject matter of claims 11 and 12. FIG.

p0010According to the invention, the optoelectronic converter of the type mentioned above to a support unit with a mounting surface, is mounted on the radiation emitting and / or receiving body. The mounting surface is a number of terminal members associated with electrical connecting surfaces intended for surface mounting of the component, for example, on a circuit board and which are each connected by means of electrical connecting means electrically conductively connected to an electrical contact of the body. The connecting parts are constructed and arranged adjacent to the body such that, relative to the mounting surface, the maximum height of the body including all the connecting means and possibly Andeckmittel for the body is smaller than the distance between the mounting surface and a plane defined by the connecting surfaces contacting plane.

p0011This inventive optoelectronic transducer has compared to the initially described known optoelectronic converters has the advantage that it can be easily mounted on a circuit board (z. B. board, ceramic substrate or hybrid substrate) by set and with his pads on circuit traces of the circuit board pads are connected by means of an electrically conductive binder to the conductive traces. The transducer is thus such example can be mounted on a printed circuit board that the body between the support member and the circuit board is arranged.

p0012In a preferred development of the optoelectronic transducer of the invention the radiation-emitting and / or receiving body is mounted on the carrier unit that its radiation outlet surface is directed towards the mounting surface. The carrier unit in this case consists of a permeable at least for a part of the radiation emitted from the body and / or received radiation material.

p0013This has the special advantage tion modifiers leads that the radiation emitted by the body and / or received radiation without much reflection losses and losses due to aberrations in an optical fiber or other optical arrangement or in the body can be coupled.

p0014In a further preferred embodiment of the optoelectronic transducer of the invention it is provided that the carrier unit has a support plate with a recess, that on a bottom surface of the recess is provided the mounting surface, and that at least partial regions of side walls of the recess are used as connecting parts.

p0015The advantage of this embodiment is, in particular, that a plurality can be manufactured by the inventive optoelectronic converters in composite disk simultaneously in a simple manner. A separate accurate positioning and mounting of the connecting parts on the carrier plate is not necessary.

p0016In an advantageous development of the invention, the support plate is made of an insulating material or the carrier plate is optionally at least partially in the recess and on the connecting parts with an insulating layer. In the recess and on the connecting parts, a number of the electrical contacts of the radiation-emitting and / or receiving body is connectable, electrically conducting connecting tracks is provided, which are structured such that on the connecting parts, a number of pads which is suitable for surface mounting of the component is, are formed. This has the particular advantage that the electrically conductive connection tracks (so mask art + vapor deposition or sputtering of metal layers) can be easily prepared by conventional methods of semiconductor technology.

p0017In a particularly preferred embodiment of the optoelectronic transducer according to the invention, the carrier unit has a means for focusing the radiation, whereby advantageously the emitted or received radiation can be coupled out without great losses by total reflection at interfaces of the transducer or eingkoppelt therein.

p0018In another advantageous development of the invention and its embodiments, the carrier plate is made of an electrically insulating material or is at least partially provided with an insulating layer and are on the support plate or on the insulating layer at least two patterned metallization is applied, arranged on which electrically conductive connecting parts are.

p0019This has the particular advantage that the dimensions and the positions of the electrically conductive terminal parts the receiving body can be including the connection conductors and / or covering means adapted for the body optionally in a simple manner emitting the dimensions of the located on the mounting surface radiation and / or.

p0020In a further preferred embodiment of the optoelectronic transducer of the invention a further plate is provided on the side opposite the body side of the carrier plate.

p0021Thereby, it is possible to manufacture the backing unit consists of materials having different refractive indices and thereby optimize the amount and structure of the optical image of the optoelectronic converter. Moreover, advantageously, the plate further comprise means for focusing the radiation.

p0022In a particularly preferred embodiment of the optoelectronic transducer of the invention, at least the radiation-emitting and / or receiving body is provided with a plastic cover or a different type of cover. This the body against moisture and against mechanical damage is easily protected.

p0023Further features, advantages and expediencies of the invention will become apparent from the following description of five embodiments in conjunction with Figures 1 to 12th Show it:<ul><li>Figure 1 is a schematic sectional view through a first exemplary embodiment of an optoelectronic transducer according to the invention;</li><li>Figure 2 is a schematic representation of a plan view of the opto-electronic transducer of Figure 1;</li><li>Figure 3 is a schematic sectional view through a second embodiment of the optoelectronic transducer of the invention;</li><li>Figure 4 is a schematic representation of a plan view of the opto-electronic transducer of Figure 3;</li><li>Figure 5 is a schematic sectional view through a third embodiment of an optoelectronic transducer according to the invention;</li><li>Figure 6 is a schematic sectional view of a fourth embodiment of an optoelectronic transducer according to the invention;</li><li>Figure 7 is a schematic representation of a plan view of the opto-electronic transducer of Figure 6;</li><li>Figure 8 is a schematic sectional view of a fifth embodiment of an optoelectronic transducer according to the invention; </li><li>Figure 9 is a schematic diagram for explaining a process sequence for producing a plurality of optoelectronic transducers according to the invention shown in FIG 8, and</li><li>Figures 10 and 11 show schematic representations for explaining a method for manufacturing a plurality of optoelectronic transducers according to the invention according to FIG. 6</li></ul>

p0024In the figures, similar components of the various embodiments are provided with the same reference numerals.

p0025In the optoelelektronischen converter of Figure 1 and 2, the support unit 2 a support plate 7 having a trapezoidal recess 8. On the bottom surface 9 and the side surfaces 10,11 of the recess 8 and on the upper sides of the connecting parts 24,25 4.5 two separate electrically conducting connection tracks 12,13 are for example applied in the form of metallization. On the connecting parts 4,5 two pads 16,17 of the optoelectronic transducer are thereby formed.

p0026On a mounting surface 3 of the recess 8, a radiation emitting and / or receiving body 1 is attached such that its bottom-contact 22 at least partially rests on the electrically conductive terminal sheet 12 and with this, for example by means of an Au-Sn solder or by means of another suitable electrically conductive binder connected is. A top contact 23 of the body 1 is (a bonding wire z. B.) connected by means of a connecting conductor 24 to the electrically conductive connection sheet 13.

p0027The body 1 is for example a light emitting diode, a photodiode (PIN-Fotodoide) or a Vertical Cavity Surface Emitting Laser (VCSEL).

p0028The carrier plate 7 is electrically insulating and consists for example of a material permeable to that of the body 1 emitted or received radiation glass, plastic, sapphire, diamond or semiconductor material. For wavelengths λ> 400 nm, for example, SiC for λ> 550 nm GaP for λ> 900 nm GaAs and λ> 1100 nm, silicon can be used. The recess 8 is made, for example by means of etching, sawing or milling. Likewise, an electrically conductive carrier plate 7, the z. B. is made of metal, be used, but which then in the recess and on the connecting parts 4.5 at least partially with an insulating layer 15 (eg. As an oxide layer or plastic layer, etc. .) is provided.

p0029The electrically conducting connection tracks 12, 13 consist for example of aluminum, of an aluminum base alloy or from an Au-multilayer system. It is also conceivable that in the case of using a support plate 7 made of a semiconductor material in the recess 8, as well as on the upper sides 24, 25 of the connecting parts 4, 5 by means of suitable doping of the connecting webs are formed. To make such doping can the ordinarily skilled artisan methods known today semiconductor technology, such as ion implantation, are used.

p0030Between the radiation exit and / or -eintrittsfläche 6 of the body 1 and the support plate 7 is to improve the light extraction from the body 1 or from the carrier plate 7, an optical coupling medium 29, for example, a molding resin. The improvement of the light extraction based on an increase of the angle at which total reflection occurs. As an essential feature, the coupling medium 29 only a slight absorption of the light emitted by the Halbbleiterchip 1 and / or received radiation.

p0031For completeness, it should be mentioned at this point that the radiation exit and / or -eintrittsfläche 6 of the radiation-emitting body 1 is the area through which the largest percentage of the radiation generated in the body 1 to flow from this. Similarly, the radiation entrance surface of a radiation receiving body 1 is the surface through which enters a received radiation into the body first

p0032The pads 16,17 define a contact plane (by the dashed line 14 indicated), whose distance from the bottom surface 9 is greater than the maximum height of the body 1 including connecting conductors 26 and an optionally provided chip cover 27 which flakes for example, a quartz beads or filled resin or consists of an acrylate. The chip cover 27 serves in particular to protect the body 1 against humidity and mechanical damage.

p0033On its opposite side of the recess 8, the carrier plate 7, a means 21 for focusing the radiation emitted by the body 1 and / or received radiation, eg. As a spherical lens, an aspherical lens or a diffractive optics. This may for example be formed by etching or grinding in the carrier plate 7 or made separately and applied for example by means of soldering, gluing or anodic bonding on the support plate. 7

p0034The optoelectronic transducer illustrated in Figures 3 and 4, the support bar 7 a flat upper surface 28, on which the electrically conductive connection tracks 12, 13 are applied. The support plate 7 can be made of an electrically insulating material (eg. As material as in the above embodiment of Figure 1 and 2) or be electrically conductive, in which case they at least partially with an electrically insulating layer 15 (eg. B. oxide or plastic layer, etc.) is provided.

p0035As in the embodiment of Figures 1 and 2 again, the body 1 is so fixed to a mounting surface 3 of the carrier plate 7, that it is at least a part of its bottom contact 22 on the electrically conductive connecting web 12 rests and is connected to this electrically conductive. On the electrically conducting connection tracks 12,13 are, for example, by soldering or gluing connecting parts 4 ', 5' are fastened, which are electrically conductive, so that the upper sides 24, 25 of the connecting parts 4 ', 5', the electrical terminal pads 16 ', 17' of the optoelectronic transducer form.

p0036The connecting parts 4 ', 5' consist for example of highly conductive silicon, metal or other material having high electrical conductivity. As a binder between the connection parts 4 ', 5' and the electrically conducting connection tracks 12,13 is, for example, a metallic solder or an electrically conductive plastic is used. Also, the connecting parts 4 ', 5' by means of eutectic bonding can be attached to the connection tracks 12,13.

p0037Suitable materials for the support plate 7 and the electrically conductive connection tracks 12, 13 are, for example, the materials according to specified with respect to the former embodiment.

p0038The support plate 7 has also here on their opposite side on the body 1, a means 21 for focusing the radiation emitted by the body and / or received radiation. Representative of this is shown a diffractive optics in FIG. 3

p0039Moreover, the body 1 may be protected by a chip covering 27 against moisture and against mechanical damage (materials for the chip cover 27 as indicated above to Figure 1) also in this embodiment.

p0040The embodiment of Figure 5 differs from that of Figures 3 and 4, characterized in that on the opposite assembly face 3 side of the support plate 7, a further plate 18 is arranged. The other plate 18 consists for example of a different material as the carrier plate 7. With a suitable selection of these materials, eg. As glass for the carrier plate 7 and silicon for another plate 18, the high frequency characteristics of the transducer can be improved and the capacity of the optoelectronic converter be lowered. In addition, can be optimized by different refractive indices of the other plate 18 and the support plate 7, the installation height and the optical imaging of opotelektronischen converter.

p0041As shown in Figure 5, here is not the carrier plate 7, but the other plate 18, a means 21 for focusing the radiation, in this case, a spherical or an aspherical lens 28.

p0042The embodiment of Figures 6 and 7 differs from the embodiment shown in Figures 1 and 2 in that the recess 8 having in the support plate 7 in the form of a downwardly narrowing from above mine, for example, is produced by means of etching. When connecting parts 4,5 this cuts the side wall of the pit are used. This has the advantage that the pads 16, 17 in beliegiger arrangement on top of the side wall of the pit may be arranged, whereby for example the design of the conductor tracks is less restricted on one of the optoelectronic transducer associated conductor plate.

p0043As with the embodiment of Figure 3 (z. B. called silicon jumper chips) can also here on the connection tracks 12,13 electrically conductive connecting parts 4 '5,' be ', 17' fixed with pads 16, the pads 16 ' 17 'for example, are realized in the form of metal layers.

p0044On the opposite side of the pit of the support plate 7 is a spherical or aspherical lens separately prepared is applied, for example by gluing, in this embodiment as a means 21 for focusing the radiation. Instead of the spherical or aspherical lens, a diffractive optic separately prepared may be applied or formed in the carrier plate. 7 The latter is of course also for the spherical or aspherical lens.

p0045In the embodiment of Figure 8 is the support plate 7 is substantially identical to the carrier plate of Figure 1 is formed (compare the related description). Similarly, the carrier plate can be designed similar to the embodiment of FIG. 6 and 7 In addition to the support plate 7, the support unit 2 here but as with the embodiment of Figure 5 is a further plate 18 in which a means 21 is formed for focusing the radiation or can also be applied. With this embodiment, there are thus the same characteristics and additional advantages as for the embodiment of FIG. 5

p0046Using the plots shown in Figure 9, the process flow for the simultaneous production of a plurality of optoelectrochemical Sichen transducers according to the figure 8 will be explained below:<ul><li>First, a majority are in a support plate 30 consisting of the material for the support plates 7 (here, for example, glass), for example, by etching or milling manufactured by recesses. 8</li><li>Below the surface of the carrier plate 30 are applied, for example, a plurality of connecting webs 12,13 a mask technique and vapor deposition or sputtering on subregions.</li><li>As a next step, a plurality of fixed body 1 and the contacts 22,23 for the connection tracks 12,13. B. electrically connected by an electrically conductive solder or by means of connecting conductors 26 (bonding wires) into the recesses 8.</li><li>If necessary, then the gaps between the radiation exit faces of the body 1 and the carrier disc 30 each with a coupling medium 29 (for. Example, resin) are filled. This can for example take place by means of a micro dosing, with the coupling medium is injected directly into the space.</li><li>can subsequently, if provided, the recesses 8 are filled with a casting resin or an acrylate, so that the body 1 are inclusive of the connection conductors 26 each provided with a chip covering 27th</li><li>Separately from the production of the carrier plate 30 with the bodies 1, a disk 31, the manufacturing method of the material of the disc 18 of Figure 8, z. B. silicon, there are provided with a plurality of means 21 for focusing the Stahlung (such as stated above).</li><li>The disc 31 is then connected to the carrier plate 30 for example by soldering, adhesive bonding or anodic bonding. Likewise, however, also can be the disk 31 before the assembly of the body 1 is connected to the support plate 30 therewith. The disc assembly is then separated z. B. by sawing.</li><li>Before the separation of the laminated structure the optoelectrochemical Sichen converters can be tested electrically and optically.</li></ul>

p0047In the below with reference to Figures 10 and 11 described method for fabricating a plurality of opto-electro Sichen transducers according since Figures 6 and 7, a support disk 30 is analogous to the method described above initially provided with a plurality of recesses 8, on top of the carrier plate 30 a applied plurality of connecting tracks 12,13 and secured in the recesses a plurality of body. 1 As regards connection of the electrical contacts of the body 1 with the connection tracks, as well as with respect to the coupling medium and chip cover also applies the same as indicated with respect to FIG. 9

p0048The difference from the aforementioned method is that, first, here the means 21 adapted to Fokinssieren of the radiation in the carrier plate or may be applied to these and, second, that with the connection tracks pairwise interconnected electrically conductive connecting parts 4 ', 5' (connection part pairs 32) pads 16 ', 17' (for example, metal layers) are applied. Subsequently, the carrier plate 30 is optionally isolated together with the connector pairs 32 by electrical and / or optical examination of the converter into individual optoelectronic converter.