Reflection type optical semiconductor device and manufacturing method thereof

Abstract

To provide a reflection type optical semiconductor device capable of obtaining precise detection signals with less noise, and a manufacturing method thereof.SOLUTION: In a reflection type optical semiconductor device, a light-emitting element chip 1, and a light-receiving element chip 2 having a light-receiving element and a through hole 9 are mounted to a chip mounting part 31 of a mounting member 3 while the light-emitting element chip 1 is arranged in the through hole 9. The light-emitting element chip 1 is mounted, while a light-emitting element electrode 4 arranged on a light-emitting element chip mounting face is connected by a conductive adhesion member 11. In the light-receiving element chip 2, the light-receiving element chip mounting face is adhered by a film-like adhesion member 12 and insulated from the chip mounting part 31. A reflection type optical semiconductor device manufacturing method includes steps of preparing a semiconductor substrate for forming the light-receiving element chip 2, adhering a film-like adhesion member 12 with the through hole 9 on one face of the semiconductor substrate serving as a mounting face of the light-receiving element chip 2, and forming a chip 2 by segmenting the semiconductor substrate.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a reflective optical semiconductor device constituted by a light-emitting element chip having a light-emitting element and a light-receiving element chip having a light-receiving element, and a method for manufacturing the same. [Background technology]

[0002] For example, a reflective optical semiconductor device used in a reflective encoder or the like is composed of a light-emitting element chip equipped with a light-emitting element and a light-receiving element chip equipped with a light-receiving element, and is configured so that light emitted from the light-emitting element is reflected by a reflector arranged opposite the reflective optical semiconductor device and enters the light-receiving element to obtain a detection signal.

[0003] A reflective optical semiconductor device has a configuration in which a light-emitting element chip and a light-receiving element chip having a through hole in which the light-emitting element chip is disposed are mounted on a die pad of a printed wiring board (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2005-121593 A Summary of the Invention [Problem to be solved by the invention]

[0005] Fig. 16 is an explanatory diagram showing an example of a reflective optical semiconductor device, and shows an example of a reflective optical semiconductor device 400 having a configuration in which a light emitting element chip 1 and a light receiving element chip 2 are mounted on a mounting member 3. Fig. 17 is a schematic cross-sectional view explaining the reflective optical semiconductor device shown in Fig. 16, and corresponds to a cross-sectional view in the left-right direction of the drawing that passes through the centers of the light emitting element chip 1, the light emitting element wiring 10, and the lead terminal 32 connected to the light emitting element wiring 10 of the reflective optical semiconductor device 400 shown in Fig. 16.

[0006] A light-emitting element constituted by, for example, a light-emitting diode is disposed on the light-emitting element chip 1. A light-emitting element electrode 4 is disposed on each of the light-emitting surface on the upper surface of the light-emitting element chip 1 and the mounting surface on the lower surface of the light-emitting element chip 1, and the light-emitting element electrode 4 on the light-emitting surface is connected to the cathode of the light-emitting diode, and the light-emitting element electrode 4 on the mounting surface is connected to the anode of the light-emitting diode. A light-emitting unit 5 that emits light is disposed on the light-emitting surface.

[0007] A light receiving element array 7 consisting of a plurality of light receiving elements 6 is arranged on the light receiving surface on the upper surface of the light receiving element chip 2. The light receiving elements 6 can be composed of, for example, photodiodes. The cathode or anode of the photodiode is connected to a light receiving element electrode 8 arranged on the light receiving surface of the light receiving element chip 2 by wiring or the like (not shown). In addition, the light receiving element chip 2 has a through hole 9 arranged in the center, and wiring 10 for a light emitting element is arranged on the light receiving surface.

[0008] The light emitting element chip 1 and the light receiving element chip 2 are mounted on a mounting member 3. The mounting member 3 includes a chip mounting portion 31 and lead terminals 32, and may be formed of, for example, a printed wiring board or a lead frame. The light emitting element chip 1 and the light receiving element chip 2 are mounted on the chip mounting portion 31. Reference numeral 33 denotes a resin filled between the chip mounting portion 31 and the lead terminals 32.

[0009] The light-emitting element chip 1 is mounted on the chip mounting section 31 by connecting the light-emitting element electrode 4 arranged on the mounting surface to the upper surface of the chip mounting section 31 with a conductive adhesive member 11 made of, for example, silver paste applied using a dispenser. In the example shown in Fig. 17, a part of the chip mounting section 31 functions as a lead terminal connected to the anode of the light-emitting diode.

[0010] The light receiving element chip 2 is mounted on the chip mounting section 31 by placing the light emitting element chip 1 in the through hole 9 and adhering its lower mounting surface to the upper surface of the chip mounting section 31 with an insulating adhesive member 12 made of, for example, an epoxy resin containing a filler that is applied using a dispenser.

[0011] The light-emitting element electrode 4 on the light-emitting surface of the light-emitting element chip 1 and the light-emitting element wiring 10 arranged on the light-receiving surface of the light-receiving element chip 2 are connected by metal wires 13. The light-receiving element electrode 8 on the light-receiving surface of the light-receiving element chip 2 and the lead terminal 32, and the light-emitting element wiring 10 and the lead terminal 32 are also connected by metal wires 13.

[0012] In the reflective optical semiconductor device 400 thus configured, the light receiving chip 2 is mounted on the mounting member 3 as follows. First, the insulating adhesive member 12 in a paste form is applied on the chip mounting portion 31 of the mounting member 3 in a size narrower than the size of the light receiving chip 2. Next, a load is applied so that the light receiving surface is not inclined, and the light receiving chip 2 is placed on the insulating adhesive member 12. By applying a load to the light receiving chip 2 in this manner, the insulating adhesive member 12 spreads without any gaps between the light receiving chip 2 and the chip mounting portion 31. Thereafter, the insulating adhesive member 12 is hardened, and the light receiving chip 2 is mounted on the chip mounting portion 31. Here, if the insulating adhesive member 12 does not spread without any gaps between the light receiving chip 2 and the chip mounting portion 31 and there is a portion between the light receiving chip 2 and the chip mounting portion 31 where the insulating adhesive member 12 does not exist, a leak current may occur between the light receiving chip 2 and the chip mounting portion 31. In addition, the insulating adhesive material 12 has internal stress due to shrinkage associated with hardening, and when temperature changes occur due to the passage of electricity during the manufacturing process and operation, cracks may occur in the resin in contact with the filler in the insulating adhesive material 12, causing leakage current between the light receiving element chip 2 and the chip mounting portion 31, and in some cases, a short circuit may occur.

[0013] In addition, since the conductive adhesive member 11 and the insulating adhesive member 12 are applied using a dispenser, the thickness of the adhesive member varies. In particular, when the insulating adhesive member 12 is applied to the chip mounting portion 31 to mount the light receiving element chip 2 having a large area, the thickness of the insulating adhesive member 12 varies, and when the light receiving element chip 2 is placed on the insulating adhesive member 12, the pressure applied varies, so that it may be difficult to align the height direction position of the light receiving surface of the light receiving element chip 2 with the height direction and position of the light emitting surface of the light emitting element chip 1 and to mount the light receiving surface without tilting it.

[0014] For example, if a tilt occurs on the light-receiving surface, the distance from the light-emitting portion 5 of the light-emitting element chip 1 to the reflector arranged opposite the light-emitting element chip 1 and the distance from the reflector to each light-receiving element 6 that constitutes the light-receiving element array 7 will differ, and the level of the detection signal will be lower than when there is no tilt on the light-receiving surface and the respective distances are equal.

[0015] In particular, when multiple light-receiving element arrays 7 are arranged facing each other across the light-emitting element chip 1, as in the reflective optical semiconductor device 400 shown in Figure 16, the variation in the distance from the light-emitting portion 5 of the light-emitting element chip 1 to the reflector arranged opposite the light-emitting element chip 1, and the distance from the reflector to each light-receiving element 6 that constitutes the light-receiving element array 7, becomes large, and there is a risk that the signal-to-noise ratio of the detection signal will be deteriorated compared to a case where there is no inclination of the light-receiving surface and there is little variation in the respective distances.

[0016] As described above, when a leakage current or a current due to a short circuit occurs, it cannot be distinguished from the detection signal of the reflective optical semiconductor device 400, and an accurate detection signal cannot be obtained from the reflective optical semiconductor device 400. In addition, when the light-receiving element chip is mounted at an angle, the level of the detection signal decreases and the S / N ratio deteriorates.

[0017] Therefore, an object of the present invention is to provide a reflective optical semiconductor device that does not generate leakage current or current due to short circuit, has little inclination of the light receiving surface, and can obtain an accurate detection signal with little noise, and a manufacturing method thereof. [Means for solving the problem]

[0018] A reflective photosemiconductor device according to one embodiment of the present invention is a reflective photosemiconductor device in which a light-emitting element chip having a light-emitting element and a light-receiving element chip having a plurality of light-receiving elements and through holes are mounted on a conductive chip mounting portion of a mounting member by disposing the light-emitting element chip in the through hole of the light-receiving element chip, wherein the light-emitting element chip has light-emitting element electrodes disposed on its light-emitting surface and its light-emitting element chip mounting surface, respectively, and the light-emitting element electrodes disposed on the light-emitting element chip mounting surface are connected to the chip mounting portion by a conductive adhesive member and mounted, and the light-receiving element chip has a light-receiving element electrode disposed on its light-receiving surface, and the light-receiving element chip is mounted insulated from the chip mounting portion by a film-like adhesive member.

[0019] Furthermore, a method for manufacturing a reflective optical semiconductor device according to another aspect of the present invention includes the steps of: preparing a semiconductor substrate for forming a light-receiving element chip having a plurality of light-receiving elements and through holes, and adhering a film-like adhesive member having an opening at a position corresponding to the through hole to one surface of the semiconductor substrate which serves as a mounting surface for the light-receiving element chip; forming a light-receiving element chip by dividing the semiconductor substrate into individual pieces and forming a light-receiving element chip having the film-like adhesive member adhered to the light-receiving element chip mounting surface and a light-receiving element electrode disposed on the light-receiving surface; preparing a light-emitting element chip having a light-emitting element and a light-emitting element electrode on the light-emitting element chip mounting surface, and mounting the light-emitting element chip by connecting the light-emitting element electrode disposed on the light-emitting element chip mounting surface to a chip mounting portion of a mounting member by a conductive adhesive member; and mounting the light-receiving element chip by adhering the light-receiving element chip mounting surface to the chip mounting portion by the film-like adhesive member so that the light-emitting element chip is disposed in the through hole of the light-receiving element chip and insulated from the chip mounting portion.

[0020] A method for manufacturing a reflective optical semiconductor device according to still another aspect of the present invention includes preparing a semiconductor substrate for forming a light-receiving element chip having a plurality of light-receiving elements and through holes, and covering with an insulating film one surface of the semiconductor substrate that will be the mounting surface for the light-receiving element chip and the inner wall surface of the through hole with an insulating film, adhering a conductive film-like adhesive member to the insulating film on one surface of the semiconductor substrate, thereby covering the through hole with the conductive film-like adhesive member, and dividing the semiconductor substrate into individual pieces to form a light-receiving element chip having a light-receiving element electrode disposed on its light-receiving surface. the light-receiving element chip mounting process includes a light-receiving element chip forming process, a light-receiving element chip mounting surface being bonded to the chip mounting portion by the conductive film-like adhesive member and mounted insulated from the chip mounting portion with the conductive film-like adhesive member exposed in the through hole, and a light-emitting element chip mounting process including a light-emitting element chip having a light-emitting element and a light-emitting element electrode on its light-emitting surface and light-emitting element chip mounting surface, and mounting the light-emitting element electrode on the light-emitting element chip mounting surface by connecting it to the conductive film-like adhesive member exposed in the through hole. Effect of the Invention

[0021] According to the reflective optical semiconductor device of the present invention, the mounting surface of the light receiving element chip is bonded to the chip mounting part with a film-like adhesive member and is mounted insulated from the chip mounting part, so that no leakage current or current due to short circuit occurs, and the variation and inclination of the height direction of the light receiving element chip is small, making it possible to obtain an accurate detection signal with little noise. Also, according to the manufacturing method of the reflective optical semiconductor device of the present invention, by simply adding a process of bonding a film-like adhesive member to one side of the semiconductor substrate for forming the light receiving element chip to the normal light receiving element chip forming process, it is possible to easily form a light receiving element chip with a film-like adhesive member bonded to the mounting surface, and since there is no leakage current or the like and the variation and inclination of the height direction of the light receiving element chip is small, it is possible to easily manufacture a reflective optical semiconductor device that can obtain an accurate detection signal with little noise. [Brief description of the drawings]

[0022] [Figure 1] FIG. 1 is an explanatory diagram of one embodiment (embodiment 1) of a reflective optical semiconductor device according to one aspect of the present invention. [Diagram 2] 2 is a schematic cross-sectional view of the reflective optical semiconductor device of FIG. 1. [Diagram 3] FIG. 4 is a schematic cross-sectional view of a reflective optical semiconductor device (embodiment 2) according to another embodiment of the present invention. [Figure 4] FIG. 4 is a schematic cross-sectional view of a reflective optical semiconductor device (Embodiment 3) according to still another embodiment of the present invention. [Diagram 5] FIG. 4 is an explanatory diagram of an adhesive member forming step in one embodiment (Embodiment 1) of the method for producing a reflective optical semiconductor device, which is another aspect of the present invention. [Figure 6] FIG. 2 is an explanatory diagram of a light-receiving element chip forming process according to the first embodiment. [Figure 7] FIG. 2 is an explanatory diagram of a light-emitting element chip mounting step according to the first embodiment. [Figure 8] FIG. 2 is an explanatory diagram of a light-receiving element chip mounting process according to the first embodiment. [Figure 9] FIG. 4 is an explanatory diagram of an adhesive member forming step in another embodiment (embodiment 2) of the method for producing a reflective optical semiconductor device, which is another aspect of the present invention. [Figure 10] FIG. 11 is an explanatory diagram of a light-receiving element chip forming process according to the second embodiment. [Figure 11] 10 is an explanatory diagram of a light-receiving element chip mounting process according to the second embodiment. FIG. [Figure 12] FIG. 4 is an explanatory diagram of an adhesive member forming step in one embodiment (Embodiment 3) of the method for producing a reflective optical semiconductor device, which is still another aspect of the present invention. [Figure 13] FIG. 11 is an explanatory diagram of a light-receiving element chip forming process according to the third embodiment. [Figure 14] FIG. 11 is an explanatory diagram of a light-receiving element chip mounting process according to the third embodiment. [Figure 15] FIG. 10 is an explanatory diagram of a light-emitting element chip mounting process according to the third embodiment. [Figure 16]FIG. 1 is an explanatory diagram showing an example of a reflective optical semiconductor device according to a related art; [Figure 17] 17 is a schematic cross-sectional view of the reflective optical semiconductor device of FIG. 16. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] Next, the embodiments of the reflective optical semiconductor device of the present invention and the manufacturing method thereof will be described with reference to the drawings, but the present invention is not limited to these embodiments and embodiments, and the members, materials, etc. described below can be modified in various ways within the scope of the present invention. Also, in the drawings, the same reference numerals indicate the same or equivalent items, and the size and positional relationship between each component are for convenience and may not strictly reflect the actual situation.

[0024] (Embodiment 1) First, a first embodiment of a reflective optical semiconductor device according to the present invention will be described. Fig. 1 is an explanatory diagram of the first embodiment of the reflective optical semiconductor device according to the present invention, and Fig. 2 is a schematic cross-sectional view of the reflective semiconductor device of Fig. 1, which corresponds to a cross-sectional view in the left-right direction of the drawing passing through the centers of the light-emitting element chip 1, the wiring 10 for the light-emitting element, and the lead terminal 32 connected to the wiring 10 for the light-emitting element of the reflective optical semiconductor device 100 shown in Fig. 1. As shown in Figs. 1 and 2, in the reflective optical semiconductor device 100 of this embodiment, the light-emitting element chip 1 and the light-receiving element chip 2 are mounted on a mounting member 3.

[0025] A light-emitting element constituted by, for example, a light-emitting diode is disposed on the light-emitting element chip 1. A light-emitting element electrode 4 is disposed on each of the light-emitting surface on the upper surface of the light-emitting element chip 1 and the mounting surface (light-emitting element chip mounting surface) on the lower surface of the light-emitting element chip 1, and the light-emitting element electrode 4 on the light-emitting surface is connected to the cathode of the light-emitting diode, and the light-emitting element electrode 4 on the mounting surface is connected to the anode of the light-emitting diode. A light-emitting unit 5 that emits light is disposed on the light-emitting surface.

[0026] A light receiving element array 7 consisting of a plurality of light receiving elements 6 is arranged on the light receiving surface on the upper surface of the light receiving element chip 2. The light receiving elements 6 can be composed of, for example, photodiodes. The cathode or anode of the photodiode is connected to a light receiving element electrode 8 arranged on the light receiving surface of the light receiving element chip 2 by wiring or the like (not shown). In addition, the light receiving element chip 2 has a through hole 9 arranged in the center, and wiring 10 for a light emitting element is arranged on the light receiving surface.

[0027] 2, the light-emitting element chip 1 is mounted by connecting the light-emitting element electrode 4 arranged on the mounting surface to a conductive chip mounting portion 31 with a conductive adhesive member 11. Since the light-emitting element chip 1 has a small area, even if the light-emitting element chip 1 is mounted using, for example, silver paste applied with a dispenser as the conductive adhesive member 11, the inclination of the light-emitting surface is very small.

[0028] Meanwhile, the mounting surface (light receiving element chip mounting surface) on the lower surface of the light receiving element chip 2 is bonded and mounted to a conductive chip mounting section 31 on which the light emitting element chip 1 is mounted, by an insulating film-like adhesive member 12. By using the insulating film-like adhesive member 12, the light receiving element chip 2 is mounted insulated from the chip mounting section 31. The insulating film-like adhesive member 12 has an opening at a position corresponding to the through hole 9, enabling the light emitting element chip 1 to be connected to and mounted on the chip mounting section 31. The insulating film-like adhesive member 12 can be composed of, for example, a die attach film.

[0029] In this manner, in a configuration in which the light-emitting element chip 1 and the light-receiving element chip 2 are mounted on one chip mounting section 31, the mounting of the light-receiving element chip 2 is performed using the insulating film-like adhesive member 12, and the thickness of the insulating film-like adhesive member 12, the thickness of the light-emitting element chip 1, the thickness of the light-receiving element chip 2, etc. are adjusted so that the height position of the light-emitting surface of the light-emitting element chip 1 after mounting coincides with the height position of the light-receiving surface of the light-receiving element chip 2, and the inclination of the light-receiving surface of the light-receiving element chip 2 relative to the surface of the chip mounting section 31 can be kept very small. This is because, compared to an adhesive member applied using a dispenser, the insulating film-like adhesive member 12 is an adhesive member that has almost no thickness variation and is less deformed during bonding, and the light-receiving element chip 2 is mounted on the chip mounting section 31 using such an adhesive member.

[0030] As a result, the height position of the light emitting surface of the light emitting element chip 1 and the height position of the light receiving surface of the light receiving element chip 2 can be made to almost coincide with each other without generating a leakage current or a current due to a short circuit. Furthermore, since the inclination of the light receiving surface of the light receiving element chip 2 is suppressed, the distance from the light emitting part 5 of the light emitting element chip 1 to the reflector arranged opposite the light emitting element chip 1 and the distance from the reflector to each light receiving element 6 constituting the light receiving element array 7 become equal, and it is possible to suppress a decrease in the level of the detection signal. Furthermore, even when a plurality of light receiving element arrays 7 are arranged, the variation in the distance from the light emitting part 5 of the light emitting element chip 1 to the reflector arranged opposite the light emitting element chip 1 and the distance from the reflector to each light receiving element 6 constituting the light receiving element array 7 is small, and it is possible to obtain an accurate detection signal with reduced noise.

[0031] In this embodiment, the light-emitting element chip 1 and the chip mounting portion 31 can also be connected by a conductive film-like adhesive member. In this case, in order to match the height position of the light-emitting surface of the light-emitting element chip 1 with the height position of the light-receiving surface of the light-receiving element chip 2, the sum of the thickness of the light-emitting element chip 1 and the conductive film-like adhesive member and the sum of the thickness of the light-receiving element chip 2 and the insulating film-like adhesive member 12 should be set to match.

[0032] The light emitting element electrode 4 on the light emitting surface of the light emitting element chip 1 and the light emitting element wiring 10 arranged on the light receiving surface of the light receiving element chip 2 are connected by a metal wire 13. The light receiving element electrode 8 on the light receiving surface of the light receiving element chip 2 and the lead terminal 32, and the light emitting element wiring 10 and the lead terminal 32 are also connected by metal wires 13. Although not shown in Figures 1 and 2, the metal wire 13 connecting either the light receiving element electrode 8 or the light emitting element wiring 10 to the lead terminal 32 may be configured to be sealed with a resin made of, for example, epoxy resin.

[0033] (Embodiment 2) Next, a second embodiment of the reflective optical semiconductor device of the present invention will be described. Fig. 3 is a schematic cross-sectional view of the second embodiment of the reflective optical semiconductor device of the present invention, which corresponds to Fig. 2 described in the first embodiment. As in Figs. 1 and 2 described in the first embodiment, the reflective optical semiconductor device 200 of this embodiment also has a light-emitting element chip 1 and a light-receiving element chip 2A mounted on a mounting member 3. The reflective optical semiconductor device 200 of this embodiment differs from the reflective optical semiconductor device 100 described in the first embodiment in the configuration of the light-receiving element chip 2A. The configuration of the light-receiving element chip 2A will be described in detail below.

[0034] 1, the light receiving element chip 2A of this embodiment has a light receiving element array 7 composed of a plurality of light receiving elements 6 arranged on the light receiving surface on the upper surface. The light receiving elements 6 can be composed of photodiodes, for example. The cathode or anode of the photodiode is connected to a light receiving element electrode 8 arranged on the light receiving surface of the light receiving element chip 2A by wiring or the like (not shown). The light receiving element chip 2A also has a through hole 9 arranged in the center, and wiring 10 for the light emitting element is arranged on the light receiving surface.

[0035] Furthermore, as shown in FIG. 3, the light receiving element chip 2A of this embodiment is configured such that the lower mounting surface (light receiving element chip mounting surface) and the inner wall surface of the through hole 9 are covered with an insulating film 14 made of, for example, silicon dioxide.

[0036] The mounting surface of the light receiving element chip 2A in this embodiment is bonded to the conductive chip mounting portion 31 on which the light emitting element chip 1 is mounted by an insulating film-like adhesive member 12 via an insulating film 14. The insulating film-like adhesive member 12 has an opening at a position corresponding to the through hole 9, and allows the light emitting element chip 1 to be connected to and mounted on the chip mounting portion 31. The insulating film-like adhesive member 12 can be composed of, for example, a die attach film. As in the above-mentioned embodiment 1, since the film-like adhesive member 12 is insulating, the light receiving element chip 2A is mounted insulated from the chip mounting portion 31, and it is not necessarily necessary to cover the mounting surface of the light receiving element chip 2A with the insulating film 14. However, the insulating film 14 covering the inner wall surface of the through hole 9 is integrated with the insulating film covering the mounting surface of the light-receiving element chip 2A, and is formed so as to cover the mounting surface and the inner wall surface continuously without any gaps, so that when the light-emitting element chip 1 is mounted with a conductive adhesive material such as silver paste applied using a dispenser, even if the conductive adhesive material is present near the light-receiving element chip due to misalignment or the like, the light-receiving element chip 2A is mounted insulated from the chip mounting part 31 and the light-emitting element chip 1. For this reason, it is preferable to dispose the insulating film 14 that covers the inner wall surface of the through hole 9 and continuously covers the mounting surface, and the insulating film 14 may be configured to cover the area that becomes the insulated mounting structure.

[0037] In this manner, in a configuration in which the light-emitting element chip 1 and the light-receiving element chip 2A are mounted on one chip mounting section 31, the mounting of the light-receiving element chip 2A is performed by the insulating film-like adhesive member 12 via the insulating film 14, and by adjusting the thickness of the insulating film 14, the thickness of the insulating film-like adhesive member 12, the thickness of the light-emitting element chip 1, the thickness of the light-receiving element chip 2A, etc. so that the height-direction position of the light-emitting surface of the light-emitting element chip 1 after mounting coincides with the height-direction position of the light-receiving surface of the light-receiving element chip 2A, it is possible to suppress the variation in the height-direction position of the light-receiving surface of the light-receiving element chip 2A relative to the surface of the chip mounting section 31 and the inclination of the light-receiving surface of the light-receiving element chip 2A to a very small value, compared to an adhesive member applied using a dispenser. This is because the variation in the thickness of the insulating film 14 is small, the variation in the thickness of the insulating film-like adhesive member 12 is almost zero, and deformation during bonding is small, etc.

[0038] As a result, the height position of the light emitting surface of the light emitting element chip 1 and the height position of the light receiving surface of the light receiving element chip 2A can be made to almost coincide with each other without generating a leakage current or a current due to a short circuit. Furthermore, since the inclination of the light receiving surface of the light receiving element chip 2A is suppressed, the distance from the light emitting part 5 of the light emitting element chip 1 to the reflector arranged opposite the light emitting element chip 1 and the distance from the reflector to each light receiving element 6 constituting the light receiving element array 7 become equal, and it is possible to suppress a decrease in the level of the detection signal. Furthermore, even when a plurality of light receiving element arrays 7 are arranged, the variation in the distance from the light emitting part 5 of the light emitting element chip 1 to the reflector arranged opposite the light emitting element chip 1 and the distance from the reflector to each light receiving element 6 constituting the light receiving element array 7 is small, and it is possible to obtain an accurate detection signal with reduced noise.

[0039] Also in this embodiment, the light-emitting element chip 1 and the chip mounting portion 31 can be connected by a conductive film-like adhesive member. In this case, in order to match the height position of the light-emitting surface of the light-emitting element chip 1 with the height position of the light-receiving surface of the light-receiving element chip 2A, the sum of the thickness of the light-emitting element chip 1 and the thickness of the conductive film-like adhesive member should be set to match the sum of the thickness of the light-receiving element chip 2A including the insulating film 14 and the thickness of the insulating film-like adhesive member 12.

[0040] (Embodiment 3) Next, a third embodiment of the reflective optical semiconductor device of the present invention will be described. FIG. 4 is a schematic cross-sectional view of the third embodiment of the reflective optical semiconductor device of the present invention, which corresponds to FIG. 2 described in the first embodiment and FIG. 3 described in the second embodiment. As in FIGS. 1 to 3 described in the first and second embodiments, the reflective optical semiconductor device 300 of this embodiment also has a light-emitting element chip 1 and a light-receiving element chip 2B mounted on a mounting member 3. The reflective optical semiconductor device 300 of this embodiment differs from the reflective optical semiconductor device 200 described in the second embodiment in the mounting structure in which the light-emitting element chip 1 and the light-receiving element chip 2B are mounted on the chip mounting portion 31. The mounting structure of the light-emitting element chip 1 and the light-receiving element chip 2B will be described in detail below.

[0041] As with the photodetector chip 2A described in the above embodiment 2, the photodetector chip 2B of this embodiment is configured such that the mounting surface (photodetector chip mounting surface) on the underside of the photodetector chip 2B and the inner wall surface of the through hole 9 are covered with an insulating film 14 made of, for example, silicon dioxide, as shown in FIG.

[0042] The mounting surface of the light receiving element chip 2B in this embodiment is bonded to the conductive chip mounting portion 31 by the conductive film-shaped adhesive member 11A via the insulating film 14 and mounted. In the example shown in FIG. 4, the conductive film-shaped adhesive member 11A is arranged so as to be exposed in the through hole 9. The conductive film-shaped adhesive member 11A can be composed of, for example, a die attach film. In this embodiment, since the film-shaped adhesive member is conductive, the entire mounting surface of the light receiving element chip 2B is covered with the insulating film 14. Since the entire mounting surface of the light receiving element chip 2B is covered with the insulating film 14, the light receiving element chip 2B is mounted in an insulated state from the chip mounting portion 31 and the light emitting element chip 1. The insulating film 14 covering the inner wall surface of the through hole 9 is integrated with the insulating film covering the mounting surface of the light receiving element chip 2B, and is formed so as to cover the mounting surface and the inner wall surface continuously without any gaps, so that the light receiving element chip 2B is reliably insulated from the chip mounting portion 31 and the light emitting element chip 1 and mounted.

[0043] In addition, in this embodiment, the connection between the light-emitting element chip 1 and the chip mounting portion 31 can be made using a conductive film-like adhesive member, and can also be made using a conductive film-like adhesive member 11A that bonds the light-receiving element chip 2B and the chip mounting portion 31 as shown in Figure 4.

[0044] In this way, in a configuration in which the light-emitting element chip 1 and the light-receiving element chip 2B are mounted on one chip mounting portion 31, the light-receiving element chip 2B is mounted by the conductive film-like adhesive member 11A via the insulating film 14. By adjusting the thickness of the light-emitting element chip 1, the thickness of the insulating film 14, and the thickness of the light-receiving element chip 2B so that the height position of the light-emitting surface of the light-emitting element chip 1 after mounting and the height position of the light-receiving surface of the light-receiving element chip 2B match, it is possible to suppress the variation in the height position of the light-receiving surface of the light-receiving element chip 2B relative to the surface of the chip mounting portion 31 and the inclination of the light-receiving surface of the light-receiving element chip 2B to a very small value. This is because, compared to an adhesive member applied using a dispenser, the variation in the thickness of the insulating film 14 is small, there is almost no variation in the thickness of the conductive film-like adhesive member 11A, and deformation during bonding is small. In addition, by bonding the light-emitting element chip 1 and the light-receiving element chip 2B to the chip mounting portion 31 by the same conductive film adhesive member 11A, it becomes easier to align the height with the light-emitting element chip 1.

[0045] As a result, the height position of the light emitting surface of the light emitting element chip 1 and the height position of the light receiving surface of the light receiving element chip 2B can be made to almost coincide with each other without generating a leakage current or a current due to a short circuit. Furthermore, since the inclination of the light receiving surface of the light receiving element chip 2B is suppressed, the distance from the light emitting part 5 of the light emitting element chip 1 to the reflector arranged opposite the light emitting element chip 1 and the distance from the reflector to each light receiving element 6 constituting the light receiving element array 7 become equal, and it is possible to suppress a decrease in the level of the detection signal. Furthermore, even when a plurality of light receiving element arrays 7 are arranged, the variation in the distance from the light emitting part 5 of the light emitting element chip 1 to the reflector arranged opposite the light emitting element chip 1 and the distance from the reflector to each light receiving element 6 constituting the light receiving element array 7 is small, and it is possible to obtain an accurate detection signal with reduced noise.

[0046] In this embodiment, the conductive film-like adhesive member 11A that adheres and mounts the light-receiving element chip 2B to the chip mounting portion 31 and the conductive film adhesive member 11A that adheres and mounts the light-emitting element chip 1 to the chip mounting portion 31 can also be configured separately.

[0047] (Embodiment 1) Next, an embodiment of a method for manufacturing a reflective optical semiconductor device, which is another aspect of the present invention, will be described. FIGS. 5 to 8 are explanatory diagrams of embodiment 1 of the method for manufacturing a reflective optical semiconductor device of the present invention, and are explanatory diagrams of a method for manufacturing the reflective optical semiconductor device 100 shown in FIGS. 1 and 2 described in the above embodiment 1. FIGS. 5 to 8 correspond to cross-sectional views in the left-right direction of the drawing that pass through the centers of the light-emitting element chip 1, the wiring for the light-emitting element 10, and the lead terminal 32 connected to the wiring for the light-emitting element 10 in the reflective optical semiconductor device 100 shown in FIG. 1 described in embodiment 1. First, a semiconductor substrate 20 is prepared in which the light-receiving element 6 (light-receiving element array 7), the through-hole 9, the light-receiving element electrode 8, the wiring for the light-emitting element 10, etc. shown in FIG. 1 are formed in each of the regions where the light-receiving element chip is to be formed. The semiconductor substrate 20 shown in FIG. 5 shows the region where one light-receiving element chip is to be formed, the upper surface of the semiconductor substrate 20 is the light-receiving surface, and the lower surface is the mounting surface, and an insulating film-like adhesive member 12 is adhered to the mounting surface. This insulating film-like adhesive member 12 can be composed of, for example, a die attach film, and has an opening 21 corresponding to the through-hole 9. Normally, the die attach film can be patterned as desired, such as with openings, and can be aligned and bonded using a laminating device (not shown) so that the through holes 9 in the semiconductor substrate 20 and the openings 21 in the insulating film-like adhesive member 12 overlap.

[0048] Next, as shown in FIG. 6, the semiconductor substrate 20 is adhered to a dicing tape 22, and then, for example, a dicing saw is used to form cut grooves 23 in the semiconductor substrate 20 and the insulating film-like adhesive member 12 to separate the substrate into individual light receiving element chips 2.

[0049] In order to form the light-emitting element chip, a light-emitting element and a light-emitting element electrode are formed on the upper light-emitting surface and the lower mounting surface in each of the regions of a separate semiconductor substrate where the light-emitting element chip is to be formed, and the light-emitting element chips are prepared by dividing the light-emitting element chips into individual pieces. In addition, a printed wiring board or a lead frame is prepared as a mounting member. When a lead frame is used as the mounting member, as shown in FIG. 7, the mounting member 3 has a chip mounting portion 31 and a lead terminal 32, and the light-emitting element chip 1 is mounted on the upper surface of the chip mounting portion 31 of the mounting member 3 with a conductive adhesive member 11. A light-emitting element electrode 4 is disposed on the mounting surface (light-emitting element chip mounting surface) on the lower surface of the light-emitting element chip 1, and the light-emitting element electrode 4 is connected to the chip mounting portion 31 with a conductive adhesive member 11 and mounted.

[0050] 8, the light receiving element chip 2 is mounted on the chip mounting section 31 on which the light emitting element chip 1 is mounted so that the light emitting element chip 1 is disposed in the through hole 9 of the light receiving element chip 2. An insulating film-like adhesive member 12 is adhered to the mounting surface (light receiving element chip mounting surface) on the lower surface of the light receiving element chip 2, and the light receiving element chip 2 is adhered and mounted on the conductive chip mounting section 31 by this insulating film-like adhesive member 12. Since the light receiving element chip 2 is mounted on the chip mounting section 31 by the insulating film-like adhesive member 12 in this manner, the light receiving element chip 2 is mounted in a state insulated from the chip mounting section 31.

[0051] In this manner, in a configuration in which the light-emitting element chip 1 and the light-receiving element chip 2 are mounted on one chip mounting section 31, by mounting the light-receiving element chip 2 with the insulating film-like adhesive member 12, the thickness of the insulating film-like adhesive member 12, the thickness of the light-emitting element chip 1, the thickness of the light-receiving element chip 2, etc., can be adjusted so that the height position of the light-emitting surface of the light-emitting element chip 1 after mounting coincides with the height position of the light-receiving surface of the light-receiving element chip 2, and a reflective optical semiconductor device can be manufactured in which the variation in the height position of the light-receiving surface of the light-receiving element chip 2 relative to the surface of the chip mounting section 31 and the inclination of the light-receiving surface of the light-receiving element chip 2 can be kept very small. This is because, compared to an adhesive member applied using a dispenser, the insulating film-like adhesive member 12 has almost no variation in thickness and is less deformed during bonding.

[0052] Then, similar to the manufacturing method of a normal reflective optical semiconductor device, the light emitting element electrode 4 on the light emitting surface of the light emitting element chip 1 and the light emitting element wiring 10 arranged on the light receiving surface of the light receiving element chip 2 are connected by a metal wire 13, the light receiving element electrode 8 on the light receiving surface of the light receiving element chip 2 is connected to the lead terminal 32, and the light emitting element wiring 10 is connected to the lead terminal 32 by a metal wire 13, the desired resin sealing is performed, and the mounting components 3, etc. are cut, thereby completing the reflective optical semiconductor device 100 shown in Figures 1 and 2.

[0053] As described above, the manufacturing method of the reflective optical semiconductor device of this embodiment is a method of manufacturing a reflective optical semiconductor device in which the insulating film-like adhesive member 12 is attached to the mounting surface of the light-receiving element chip 2 to form the light-receiving element chip 2 in the manufacturing process of a normal reflective optical semiconductor device, thereby making it possible to manufacture a reflective optical semiconductor device in which the height position of the light-emitting surface of the light-emitting element chip 1 and the height position of the light-receiving surface of the light-receiving element chip 2 are approximately equal to each other without generating a leakage current or a current due to a short circuit. Furthermore, since the inclination of the light-receiving surface of the light-receiving element chip 2 is suppressed, the distance from the light-emitting part 5 of the light-emitting element chip 1 to the reflector arranged opposite the light-emitting element chip 1 and the distance from the reflector to each light-receiving element 6 constituting the light-receiving element array 7 become equal, making it possible to suppress a decrease in the level of the detection signal. Even when a plurality of light-receiving element arrays 7 are arranged, the variation in the distance from the light-emitting part 5 of the light-emitting element chip 1 to the reflector arranged opposite the light-emitting element chip 1 and the distance from the reflector to each light-receiving element 6 constituting the light-receiving element array 7 is small, making it possible to easily manufacture a reflective optical semiconductor device that can obtain an accurate detection signal with reduced noise.

[0054] (Embodiment 2) Next, another embodiment (embodiment 2) of the method for manufacturing a reflective optical semiconductor device, which is another aspect of the present invention, will be described. FIGS. 9 to 11 are explanatory diagrams of embodiment 2 of the method for manufacturing a reflective optical semiconductor device of the present invention, and are explanatory diagrams of the method for manufacturing the reflective optical semiconductor device 200 shown in FIG. 3 described in embodiment 2 above. FIGS. 9 to 11 correspond to cross-sectional views in the left-right direction of the drawing that pass through the centers of the light-emitting element chip 1, the wiring for light-emitting element 10, and the lead terminal 32 connected to the wiring for light-emitting element 10 in the reflective optical semiconductor device 100 shown in FIG. 1 described in embodiment 1. First, a semiconductor substrate 20A is prepared in which a light-receiving element 6 (light-receiving element array 7), a through hole 9, a light-receiving element electrode 8, and a wiring for light-emitting element 10 are formed in each of the regions to be formed with a light-receiving element chip, as in embodiment 1, and further the mounting surface on the lower surface and the inner wall surface of the through hole 9 are covered with an insulating film 14 made of, for example, silicon dioxide. The insulating film 14 can be formed by forming a deposition layer of silicon dioxide or the like by, for example, a sputtering method from the lower surface side of the semiconductor substrate 20A in which the through hole 9 is formed, so that the mounting surface and the inner wall surface of the through hole 9 can be simultaneously covered with silicon dioxide or the like. 9 shows a region in which one light receiving element chip is to be formed, with the upper surface of the semiconductor substrate 20A being the light receiving surface and the lower surface being the mounting surface. An insulating film-like adhesive member 12 is attached to this mounting surface via an insulating film 14. The insulating film-like adhesive member 12 can be made of, for example, a die attach film, and has an opening 21A corresponding to the opening of the through hole 9 covered with the insulating film 14. As in the first embodiment, the opening of the through hole 9 covered with the insulating film 14 of the semiconductor substrate 20A and the opening 21A of the insulating film-like adhesive member 12 can be aligned and attached so that they overlap.

[0055] Next, as shown in FIG. 10, the semiconductor substrate 20A is adhered to a dicing tape 22, and, for example, a dicing saw is used to form cutting grooves 23 in the semiconductor substrate 20A, the insulating film 14, and the insulating film-like adhesive member 12 to separate the substrate into individual light receiving element chips 2A.

[0056] Hereinafter, instead of the light receiving element chip 2 described in the first embodiment, a light receiving element chip 2A is mounted on the chip mounting portion 31 of the mounting member 3 on which the light emitting element chip 1 is mounted. As shown in Fig. 11, also in this embodiment, an insulating film-like adhesive member 12 is adhered to the mounting surface (light receiving element chip mounting surface) on the lower surface of the light receiving element chip 2A via an insulating film 14, and the light receiving element chip 2A is adhered and mounted on the conductive chip mounting portion 31 by this insulating film-like adhesive member 12. In this way, since the light receiving element chip 2A is mounted on the chip mounting portion 31 by the insulating film-like adhesive member 12 via the insulating film 14, the light receiving element chip 2 is mounted in a state insulated from the chip mounting portion 31.

[0057] In this manner, in a configuration in which the light-emitting element chip 1 and the light-receiving element chip 2A are mounted on one chip mounting section 31, the light-receiving element chip 2A is mounted by the insulating film-like adhesive member 12 via the insulating film 14, and the thickness of the insulating film 14, the thickness of the insulating film-like adhesive member 12, the thickness of the light-emitting element chip 1, the thickness of the light-receiving element chip 2A, etc. are adjusted so that the height-direction position of the light-emitting surface of the light-emitting element chip 1 after mounting coincides with the height-direction position of the light-receiving surface of the light-receiving element chip 2A, and the inclination of the light-receiving surface of the light-receiving element chip 2A relative to the surface of the chip mounting section 31 can be made very small, thereby manufacturing a reflective optical semiconductor device. This is because the thickness of the insulating film 14 has a small variation compared to an adhesive member applied using a dispenser, and the insulating film-like adhesive member 12 has almost no variation in thickness and is less deformed during bonding, etc.

[0058] Then, similar to the manufacturing method of a normal reflective optical semiconductor device, the light emitting element electrode 4 on the light emitting surface of the light emitting element chip 1 and the light emitting element wiring 10 arranged on the light receiving surface of the light receiving element chip 2A are connected by a metal wire 13, the light receiving element electrode 8 on the light receiving surface of the light receiving element chip 2A is connected to the lead terminal 32, and the light emitting element wiring 10 is connected to the lead terminal 32 by a metal wire 13, the desired resin sealing is performed, and the mounting member 3 etc. are cut, thereby completing the reflective optical semiconductor device 200 shown in Figure 3.

[0059] As described above, the manufacturing method of the reflective optical semiconductor device of this embodiment also involves covering the mounting surface of the light-receiving element chip 2 and the inner wall surface of the through hole 9 with an insulating film 14 in the manufacturing process of a normal reflective optical semiconductor device, and then adhering an insulating film-like adhesive member 12 to the mounting surface via the insulating film 14 to form the light-receiving element chip 2A, thereby making it possible to manufacture a reflective optical semiconductor device in which the height position of the light-emitting surface of the light-emitting element chip 1 and the height position of the light-receiving surface of the light-receiving element chip 2A are approximately aligned without the generation of leakage current or current due to short circuit. Furthermore, since the inclination of the light receiving surface of the light receiving element chip 2A is suppressed, the distance from the light emitting portion 5 of the light emitting element chip 1 to the reflector arranged opposite the light emitting element chip 1 and the distance from the reflector to each light receiving element 6 that constitutes the light receiving element array 7 become equal, making it possible to suppress a decrease in the level of the detection signal.Even when multiple light receiving element arrays 7 are arranged, there is little variation in the distance from the light emitting portion 5 of the light emitting element chip 1 to the reflector arranged opposite the light emitting element chip 1 and the distance from the reflector to each light receiving element 6 that constitutes the light receiving element array 7, making it possible to easily manufacture a reflective optical semiconductor device that can obtain an accurate detection signal with reduced noise.

[0060] (Embodiment 3) Next, an embodiment (embodiment 3) of the method for manufacturing a reflective optical semiconductor device, which is yet another aspect of the present invention, will be described. Figures 12 to 15 are explanatory diagrams of embodiment 3 of the method for manufacturing a reflective optical semiconductor device of the present invention, and are explanatory diagrams of the method for manufacturing the reflective optical semiconductor device 300 shown in Figure 4 described in embodiment 3 above. Figures 12 to 15 correspond to cross-sectional views in the left-right direction of the drawing that pass through the centers of the light-emitting element chip 1, the wiring 10 for the light-emitting element, and the lead terminal 32 connected to the wiring 10 for the light-emitting element in the reflective optical semiconductor device 100 shown in Figure 1 described in embodiment 1. First, a semiconductor substrate 20A is prepared in which a light-receiving element 6 (light-receiving element array 7), a through hole 9, a light-receiving element electrode 8, a wiring 10 for the light-emitting element, etc. are formed in each of the regions to be formed with the light-receiving element chip, as in embodiment 1, and further the mounting surface on the lower surface and the inner wall surface of the through hole 9 are covered with an insulating film 14 made of, for example, silicon dioxide, etc. 12 is the same as the semiconductor substrate 20A described in the second embodiment above, and shows an area in which one light receiving element chip is to be formed, with the upper surface of the semiconductor substrate 20A being the light receiving surface and the lower surface being the mounting surface, and a film-like adhesive member being attached to the mounting surface via an insulating film 14. Here, in this embodiment, the film-like adhesive member that is attached so as to cover the through-hole 9 is a conductive film-like adhesive member 11A. This conductive film-like adhesive member 11A can be composed of, for example, a die attach film.

[0061] Next, as shown in FIG. 13, the semiconductor substrate 20A is adhered to a dicing tape 22, and, for example, a dicing saw is used to form cutting grooves 23 in the semiconductor substrate 20A, the insulating film 14, and the conductive film-like adhesive member 11A to separate the substrate into individual light receiving element chips 2B.

[0062] In order to form the light-emitting element chip, a light-emitting element and a light-emitting element electrode are formed on the upper light-emitting surface and the lower mounting surface in each of the regions where the light-emitting element chip is to be formed on another semiconductor substrate, and the light-emitting element chip is prepared by dividing the light-emitting element chip into individual chips. In addition, a printed wiring board or a lead frame is prepared as a mounting member. When a lead frame is used as the mounting member, as shown in FIG. 14, the mounting member 3 has a chip mounting portion 31 and a lead terminal 32, and in this embodiment, the light-receiving element chip 2B is mounted on the upper surface of the chip mounting portion 31 of the mounting member 3 by a conductive film-like adhesive member 11A. The mounting surface on the lower surface of the light-receiving element chip 2B (the mounting surface of the light-receiving element chip) is mounted by the conductive film-like adhesive member 11A via the insulating film 14, so that the light-receiving element chip 2B is mounted on the chip mounting portion 31 in an insulated state.

[0063] 15, the light-emitting element chip 1 is mounted in the through-hole 9 of the light-receiving element chip 2B mounted on the chip mounting portion 31. The light-emitting element electrode 4 is arranged on the mounting surface (light-emitting element chip mounting surface) on the lower surface of the light-emitting element chip 1, and the light-emitting element electrode 4 is connected and mounted by the conductive film-like adhesive member 11A exposed in the through-hole 9. In this embodiment, the conductive film-like adhesive member 11A used for connecting the light-emitting element chip 1 to the chip mounting portion 31 can be used as is for connecting the light-emitting element chip 1 to the chip mounting portion 31, thereby realizing simplification of the manufacturing process.

[0064] In this manner, in a configuration in which the light-emitting element chip 1 and the light-receiving element chip 2B are mounted on one chip mounting section 31, the light-receiving element chip 2B is mounted by the conductive film-like adhesive member 11A via the insulating film 14, and the thickness of the insulating film 14, the thickness of the conductive film-like adhesive member 11A, the thickness of the light-emitting element chip 1, the thickness of the light-receiving element chip 2B, etc. are adjusted so that the heightwise position of the light-emitting surface of the light-emitting element chip 1 after mounting coincides with the heightwise position of the light-receiving surface of the light-receiving element chip 2B, and the inclination of the light-receiving surface of the light-receiving element chip 2B relative to the surface of the chip mounting section 31 can be made very small, thereby manufacturing a reflective optical semiconductor device. This is because the thickness of the insulating film 14 has a small variation compared to an adhesive member applied using a dispenser, and the conductive film-like adhesive member 11A has almost no variation in thickness and is less deformed during bonding, etc. In addition, since the light-emitting element chip 1 and the light-receiving element chip 2B are connected to the chip mounting portion 31 by bonding using the same conductive film adhesive material 11A, it becomes easier to align the height direction of the light-emitting surface of the light-emitting element chip 1 with the height direction of the light-receiving surface of the light-receiving element chip 2B.

[0065] Then, similar to the manufacturing method of a normal reflective optical semiconductor device, the light emitting element electrode 4 on the light emitting surface of the light emitting element chip 1 and the light emitting element wiring 10 arranged on the light receiving surface of the light receiving element chip 2B are connected by a metal wire 13, the light receiving element electrode 8 on the light receiving surface of the light receiving element chip 2B is connected to the lead terminal 32, and the light emitting element wiring 10 is connected to the lead terminal 32 by a metal wire 13, the desired resin sealing is performed, and the mounting member 3 etc. are cut, thereby completing the reflective optical semiconductor device 300 shown in Figure 4.

[0066] As described above, in the manufacturing method of the reflective optical semiconductor device of this embodiment, in the manufacturing process of a normal reflective optical semiconductor device, the mounting surface of the light-receiving element chip 2B and the inner wall surface of the through hole 9 are covered with an insulating film 14, and the conductive film-like adhesive member 11A is adhered to the mounting surface via the insulating film 14 to form the light-receiving element chip 2B, thereby making it possible to manufacture a reflective optical semiconductor device in which the height position of the light-emitting surface of the light-emitting element chip 1 and the height position of the light-receiving surface of the light-receiving element chip 2B are approximately aligned without the generation of leakage current or current due to short circuit. Furthermore, since the inclination of the light receiving surface of the light receiving element chip 2B is suppressed, the distance from the light emitting portion 5 of the light emitting element chip 1 to the reflector arranged opposite the light emitting element chip 1 and the distance from the reflector to each light receiving element 6 that constitutes the light receiving element array 7 become equal, making it possible to suppress a decrease in the level of the detection signal.Even when multiple light receiving element arrays 7 are arranged, there is little variation in the distance from the light emitting portion 5 of the light emitting element chip 1 to the reflector arranged opposite the light emitting element chip 1 and the distance from the reflector to each light receiving element 6 that constitutes the light receiving element array 7, making it possible to easily manufacture a reflective optical semiconductor device that can obtain an accurate detection signal with reduced noise.

[0067] Although the reflective optical semiconductor device and its manufacturing method of the present invention have been described above, it goes without saying that the present invention is not limited to the above-mentioned embodiment and implementation. For example, the insulating film 14 is not limited to silicon oxide. Also, the light-emitting element chip 1 may be mounted on the chip mounting portion 31 of the mounting member 3 using a conductive film-like adhesive material instead of silver paste applied using a dispenser.

[0068] (summary) (1) One embodiment of a reflective optical semiconductor device according to the present invention is a reflective optical semiconductor device in which a light-emitting element chip including a light-emitting element and a light-receiving element chip including a plurality of light-receiving elements and through holes are mounted on a conductive chip mounting portion of a mounting member by disposing the light-emitting element chip in the through holes of the light-receiving element chip, in which the light-emitting element chip has light-emitting element electrodes disposed on its light-emitting surface and its light-emitting element chip mounting surface, respectively, and the light-emitting element electrodes disposed on the light-emitting element chip mounting surface are connected to the chip mounting portion by a conductive adhesive member and mounted, and the light-receiving element chip has a light-receiving element electrode disposed on its light-receiving surface, and the light-receiving element chip is mounted insulated from the chip mounting portion by a film-like adhesive member.

[0069] According to the reflective optical semiconductor device of (1) above, the mounting surface of the light receiving element chip is reliably insulated, and the variation in the height position and inclination of the light receiving surface are reduced, making it possible to obtain an accurate detection signal with little noise.

[0070] (2) According to another embodiment, in the reflective optical semiconductor device of (1) above, the film-like adhesive member has an opening at a position corresponding to the through hole.

[0071] (3) According to another embodiment, in the reflective optical semiconductor device of (1) above, the film-like adhesive member is conductive and also functions as the conductive adhesive member, and the light-receiving element chip has the light-receiving element chip mounting surface and the inner wall surface of the through hole covered with an insulating film, and the light-receiving element chip mounting surface covered with the insulating film is adhered to the chip mounting portion by the film-like adhesive member, and is mounted insulated from the chip mounting portion and the light-emitting element chip.

[0072] According to the reflective optical semiconductor device of (3) above, the connection between the light-emitting element chip and the chip mounting portion and the connection between the light-receiving element chip and the chip mounting portion can be formed by the same film-like adhesive member.

[0073] (4) According to still another embodiment, in the reflective optical semiconductor device of (1) to (3) above, the film-like adhesive member is configured as a die attach film.

[0074] According to the reflective optical semiconductor device of (4) above, the thickness of the film-like adhesive member is highly uniform, and the variation in the height position and inclination of the light receiving surface are small, making it possible to obtain a detection signal with less noise.

[0075] (5) One embodiment of a manufacturing method of a reflective optical semiconductor device, which is another aspect of the present invention, includes a step of preparing a semiconductor substrate for forming a light-receiving element chip having a plurality of light-receiving elements and through holes, and adhering a film-like adhesive member having an opening at a position corresponding to the through hole to one surface of the semiconductor substrate which serves as a mounting surface of the light-receiving element chip; a light-receiving element chip forming step of dividing the semiconductor substrate into individual pieces, and forming a light-receiving element chip having the film-like adhesive member adhered to the light-receiving element chip mounting surface and a light-receiving element electrode disposed on the light-receiving surface; a light-emitting element chip mounting step of preparing a light-emitting element chip having a light-emitting element and a light-emitting element electrode on the light-emitting element chip mounting surface, and mounting the light-emitting element chip by connecting the light-emitting element electrode disposed on the light-emitting element chip mounting surface to a chip mounting portion of a mounting member by a conductive adhesive member; and a light-receiving element chip mounting step of adhering the light-receiving element chip mounting surface to the chip mounting portion by the film-like adhesive member so that the light-emitting element chip is disposed in the through hole of the light-receiving element chip, and mounting the light-receiving element chip insulated from the chip mounting portion.

[0076] According to the manufacturing method of the reflective optical semiconductor device of the embodiment (5) above, by simply adding a process of adhering a film-like adhesive member to one side of the semiconductor substrate on which the light-receiving element chip is formed to the process of forming a normal light-receiving element chip, it is possible to easily manufacture a reflective optical semiconductor device in which the mounting surface of the light-receiving element chip is reliably insulated and the variation in the height position and inclination of the light-receiving surface are reduced, thereby enabling an accurate and low-noise detection signal to be obtained.

[0077] (6) According to another embodiment, the method includes the steps of: preparing a semiconductor substrate for forming a light-receiving element chip having a plurality of light-receiving elements and through holes formed thereon; forming an insulating film on one surface of the semiconductor substrate which serves as a mounting surface for the light-receiving element chip and an inner wall surface of the through hole with an insulating film; forming an adhesive member on the insulating film on one surface of the semiconductor substrate, thereby covering the through hole with the conductive film-shaped adhesive member; forming a light-receiving element chip by dividing the semiconductor substrate into individual pieces and forming a light-receiving element chip having a light-receiving element electrode arranged on its light-receiving surface; mounting the light-receiving element chip by bonding the light-receiving element chip mounting surface to a chip mounting portion with the conductive film-shaped adhesive member and exposing the conductive film-shaped adhesive member in the through hole and insulated from the chip mounting portion; and mounting a light-emitting element chip having a light-emitting element and a light-emitting element electrode on its light-emitting surface and light-emitting element chip mounting surface, and connecting and mounting the light-emitting element electrode arranged on the light-emitting element chip mounting surface with the conductive film-shaped adhesive member exposed in the through hole.

[0078] According to the manufacturing method of the reflective optical semiconductor device of the embodiment (6) above, by simply adding a process of forming a light-receiving element chip in which the mounting surface of the semiconductor chip and the inner wall surface of the through hole are covered with an insulating film and adhering a film-like adhesive member to this insulating film, it is possible to easily manufacture a reflective optical semiconductor device in which the mounting surface of the light-receiving element chip is reliably insulated, the variation in the height position and inclination of the light-receiving surface are reduced, and an accurate, low-noise detection signal can be obtained.

[0079] (7) According to still another embodiment, in the method for producing a reflective optical semiconductor device according to (5) or (6) above, the film-like adhesive member is composed of a die attach film.

[0080] According to the manufacturing method of the reflective optical semiconductor device of the above embodiment (7), the variation and inclination of the height position of the light emitting surface of the light emitting element chip and the height position of the light receiving surface of the light receiving element chip are reduced, making it possible to easily manufacture a reflective optical semiconductor device that can obtain a detection signal with less noise. [Explanation of symbols]

[0081] 100, 200, 300, 400 Reflective optical semiconductor device 1 Light emitting element chip 2, 2A, 2B Photodetector chip 3 Mounting materials 31 Chip mounting section 32 Lead terminal 33 Resin 4 Light emitting element electrode 5 Light emitting part 6 Photodetector 7 Photodetector array 8 Photodetector electrode 9 Through holes 10 Light emitting element wiring 11 Conductive adhesive materials 11A Conductive film-like adhesive material 12 Insulating film-like adhesive material 13 Metal Wire 14 Insulating film 20, 20A Semiconductor Substrate 21 Aperture 22 Dicing tape 23 Cutting groove

Claims

1. A reflective optical semiconductor device in which a light-emitting element chip including a light-emitting element and a light-receiving element chip including a plurality of light-receiving elements and through holes are mounted on a conductive chip mounting portion of a mounting member by disposing the light-emitting element chip in the through holes of the light-receiving element chip, The light-emitting element chip includes: A light emitting element electrode is disposed on the light emitting surface and the light emitting element chip mounting surface, respectively; the light-emitting element electrode disposed on the light-emitting element chip mounting surface is connected to the chip mounting portion by a conductive adhesive member and mounted thereon; The light receiving element chip is A light receiving element electrode is disposed on the light receiving surface, The light receiving element chip mounting surface is adhered to the chip mounting portion by a film-like adhesive material and is mounted insulated from the chip mounting portion. Reflective optical semiconductor device.

2. 2. The reflective optical semiconductor device according to claim 1, wherein said film-like adhesive member has an opening at a position corresponding to said through hole.

3. the film-like adhesive member is conductive and also functions as the conductive adhesive member; The light receiving element chip includes: the light receiving element chip mounting surface and the inner wall surface of the through hole are covered with an insulating film; the light receiving element chip mounting surface covered with the insulating film is adhered to the chip mounting portion by the film-like adhesive member, and is mounted insulated from the chip mounting portion and the light emitting element chip; 2. The reflective optical semiconductor device according to claim 1.

4. The film-like adhesive member is a die attach film.

4. The reflective optical semiconductor device according to claim 1.

5. an adhesive member forming step of preparing a semiconductor substrate for forming a light receiving element chip having a plurality of light receiving elements and through holes, and adhering a film-like adhesive member having openings at positions corresponding to the through holes to one surface of the semiconductor substrate that will be a mounting surface for the light receiving element chip; a light-receiving element chip forming process in which the semiconductor substrate is divided into individual pieces, the film-like adhesive member is adhered to a light-receiving element chip mounting surface, and a light-receiving element electrode is disposed on a light-receiving surface to form a light-receiving element chip; a light-emitting element chip mounting process in which a light-emitting element chip is prepared, the light-emitting element chip including a light-emitting element and a light-emitting element electrode on a light-emitting element chip mounting surface, and the light-emitting element electrode arranged on the light-emitting element chip mounting surface is connected to a chip mounting portion of a mounting member by a conductive adhesive material and mounted; a light-receiving element chip mounting process in which the light-receiving element chip mounting surface is bonded to the chip mounting portion by the film-like adhesive member so that the light-emitting element chip is disposed in the through-hole of the light-receiving element chip, and the light-receiving element chip is mounted insulated from the chip mounting portion; A method for manufacturing a reflective optical semiconductor device comprising the steps of:

6. an insulating film forming step of preparing a semiconductor substrate for forming a light-receiving element chip having a plurality of light-receiving elements and through holes, and covering one surface of the semiconductor substrate serving as a mounting surface for the light-receiving element chip and an inner wall surface of the through hole with an insulating film; an adhesive member forming step of adhering a conductive film-like adhesive member to the insulating film on one surface of the semiconductor substrate, thereby covering the through hole with the conductive film-like adhesive member; a light receiving element chip forming step of dividing the semiconductor substrate into individual pieces to form light receiving element chips each having a light receiving element electrode disposed on a light receiving surface; a light-receiving element chip mounting process in which a light-receiving element chip mounting surface is bonded to a chip mounting portion by the conductive film-like adhesive member and mounted in a state in which the conductive film-like adhesive member is exposed in the through hole and is insulated from the chip mounting portion; a light-emitting element chip mounting process in which a light-emitting element chip is prepared, the light-emitting element chip having a light-emitting element and a light-emitting element electrode on a light-emitting surface and a light-emitting element chip mounting surface is prepared, and the light-emitting element electrode arranged on the light-emitting element chip mounting surface is connected and mounted by the conductive film-like adhesive member exposed in the through hole; A method for manufacturing a reflective optical semiconductor device comprising the steps of:

7. The film-like adhesive member is a die attach film.

7. A method for manufacturing a reflective optical semiconductor device according to claim 5.

Images