Reflective optical semiconductor device and method for manufacturing same

Abstract

Disclosed is a reflective semiconductor device which comprises a light-emitting element chip (2), a light-receiving element chip (1), and a mounting part (3), wherein: the light-receiving element chip (1) is mounted on the mounting part (3) by an insulating member (12); the light-emitting element chip (2) is mounted on a mounting part electrode (13C), which is disposed in a through hole (14) of the light-receiving element chip (1), by a conductive member (11); and the conductive member (11) is covered by the insulating member (12). Also disclosed is a method for manufacturing a reflective semiconductor device, wherein: an insulating member (12) is applied to a mounting part (3) where a light-emitting element chip (2) is connected and mounted by a conductive member (11); a light-receiving element chip (1) is mounted on the insulating member (12); and the light-receiving element chip (1) is pressed so that the conductive member (11) is covered by the extruded insulating member (12).

Description

Reflective optical semiconductor device and its manufacturing method

[0001] The present invention relates to a reflective optical semiconductor device including 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.

[0002] The reflective optical sensor used in the reflective encoder is configured so that light emitted from a light-emitting element provided in the reflective optical semiconductor device is reflected by a reflector arranged opposite the reflective optical semiconductor device and enters a light-receiving element, thereby obtaining a detection signal.

[0003] Generally, when a reflective optical semiconductor device is mounted on a mounting portion, a light-emitting element chip is stacked on a light-receiving element chip, and this light-receiving element chip is mounted on the mounting portion (e.g., Patent Document 1), or a light-receiving element chip having a through-hole and a light-emitting element chip placed in the through-hole are mounted on the mounting portion (e.g., Patent Document 2).

[0004] JP 2009-182028 A JP 2005-121593 A

[0005] 8 is an explanatory diagram showing an example of a reflective optical semiconductor device, in which a light-emitting element chip 2 is stacked on a light-receiving element chip 1A, and the light-receiving element chip 1A is mounted on a mounting portion 3A. A light-receiving element array 5 composed of a plurality of light-receiving elements 4 is arranged on the light-receiving element chip 1A. The light-receiving elements 4 may be composed of photodiodes, for example. The cathode or anode of the photodiode is connected to a light-receiving element electrode 6 arranged on the upper surface (light-receiving surface) of the light-receiving element chip 1A by wiring or the like (not shown).

[0006] A light-emitting element is disposed on the light-emitting element chip 2. The light-emitting element can be, for example, a light-emitting diode. A light-emitting portion 7 that emits light and a light-emitting element electrode 8 connected to the cathode of the light-emitting diode are disposed on the upper surface (light-emitting surface) of the light-emitting element chip 2, and a light-emitting element electrode 8A connected to the anode of the light-emitting diode is disposed on the lower surface (mounting surface) of the light-emitting element chip 2. The light-emitting element electrode 8 is connected to light-emitting element wiring 9 disposed on the light-receiving surface of the light-receiving element chip 1A by a metal wire 10, and the light-emitting element electrode 8A is connected to light-emitting element wiring 9A disposed on the light-receiving surface of the light-receiving element chip 1A by a conductive member 11 formed of, for example, silver paste, so that the light-emitting element chip 2 is stacked on the light-receiving element chip 1A.

[0007] The light-receiving element chip 1A on which the light-emitting element chip 2 is stacked is mounted by being adhered to a mounting section 3A made of, for example, an organic substrate with an insulating member 12 as an adhesive. Mounting section electrodes 13, 13A are arranged on the mounting section 3A, and each mounting section electrode 13 is connected to either the light-receiving element electrode 6 or the light-emitting element wiring 9 arranged on the light-receiving surface of the light-receiving element chip 1A, and the mounting section electrode 13A is connected to the light-emitting element wiring 9A with a metal wire 10.

[0008] 9 is an explanatory diagram showing another example of a reflective optical semiconductor device, in which a light-receiving element chip 1B having a through-hole 14 and a light-emitting element chip 2 disposed in the through-hole 14 are mounted on a mounting portion 3B. Similar to the light-receiving element chip 1A shown in FIG. 8, the light-receiving element chip 1B has a light-receiving element array 5 formed of a plurality of light-receiving elements 4, light-receiving element electrodes 6, and light-emitting element wiring 9 disposed therein. Unlike the light-receiving element chip 1A, the light-receiving element chip 1B does not have light-emitting element wiring 9A disposed therein, and has a through-hole 14 disposed in the center.

[0009] The light-emitting element chip 2 has the same configuration as the light-emitting element chip 2 shown in Fig. 8. As shown in Fig. 9, the light-emitting element chip 2 is placed in the through-hole 14 of the light-receiving element chip 1B, the light-emitting element electrodes on the mounting surface of the light-emitting element chip 2 are connected by conductive members to the mounting portion electrodes 13B placed in the through-hole 14, and the light-emitting element chip 2 is mounted on the mounting portion 3B. The light-emitting element electrodes 8 placed on the light-emitting surface of the light-emitting element chip 2 are connected by metal wires 10 to light-emitting element wiring 9 placed on the upper surface (light-receiving surface) of the light-receiving element chip 1B.

[0010] The light receiving element chip 1B is mounted on a mounting section 3B, which is made of, for example, an organic substrate, by bonding with an insulating member 12. As with the mounting section 3A, mounting section electrodes 13 are arranged on the mounting section 3B, and each mounting section electrode 13 is connected to either the light receiving element electrode 6 or the light emitting element wiring 9 by a metal wire 10.

[0011] The mounting portion electrodes 13B are configured to continue into the through holes 14, with their ends larger than the bottom surface of the light-emitting element chip 2 being disposed within the through holes 14. The mounting portion electrodes 13B configured in this manner are connected to the light-emitting element electrodes on the mounting surface of the light-emitting element chip 2 by conductive members, similar to the connection between the light-emitting element electrodes 8A and the light-emitting element wiring 9A shown in Fig. 8. Because the mounting portion electrodes 13B are disposed below the light-receiving element chip 1B in this manner, the light-receiving element chip 1B is mounted on the mounting portion 3B by being adhered onto the mounting portion 3B and portions of the mounting portion electrodes 13B by the insulating member 12 which serves as an adhesive.

[0012] In the reflective optical semiconductor device shown in Figures 8 and 9, if the light-emitting surface of the light-emitting element chip 2 is coated with a coating resin or the like, the light emitted from the light-emitting portion 7 will be diffused due to the lens effect of the coating resin, or variations in the thickness of the coating resin will result in variations in directivity. Therefore, the light-emitting surface of the light-emitting element chip 2 is not coated with a coating resin and is mounted in a state exposed to the outside air. On the other hand, the conductive member 11 connecting the light-emitting element electrode 8A on the mounting surface of the light-emitting element chip 2 to the light-emitting element wiring 9A or the mounting portion electrode 13B is coated with a coating material to ensure the reliability of the reflective optical semiconductor device. In particular, if a material containing silver is used as the conductive member 11, sulfurization and migration of silver will occur, reducing the reliability of the reflective optical semiconductor device, so the surface of the conductive material 11 is coated with a coating resin.

[0013] Fig. 10 is a cross-sectional schematic diagram illustrating a method for applying a coating resin to the reflective optical semiconductor device shown in Fig. 8, 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 2 and the light-emitting element wirings 9, 9A of the reflective optical semiconductor device shown in Fig. 8. As shown in Fig. 10, when the conductive member 11 is covered with the coating resin 16 discharged from the dispenser 15, a large space exists around the light-emitting element chip 2, so that the coating resin 16 can be applied onto the conductive member 11 while avoiding the light-emitting surface of the light-emitting element chip 2 without strict alignment of the dispenser 15, control of the discharge amount, etc.

[0014] On the other hand, Fig. 11 is a cross-sectional schematic diagram illustrating a method for applying a coating resin to the reflective optical semiconductor device shown in Fig. 9, and corresponds to a cross-sectional view taken along the left-right direction of the drawing, passing through the centers of the light-emitting element chip 2, the light-emitting element wiring 9, and the mounting portion electrode 13B shown in Fig. 9. As shown in Fig. 11, in order to cover the conductive member 11 with the coating resin 16, it is necessary to discharge the coating resin 16 from a dispenser 15 into the through-hole 14.

[0015] In order to perform highly accurate sensing in a typical reflective optical semiconductor device, it is necessary to minimize variation in the arrangement of the light-receiving element chip 1B and the light-emitting element chip 2. Therefore, it is preferable to set a narrow gap between the through-hole 14 and the light-emitting element chip 2. Dispensing the coating resin 16 into this narrow gap requires accurate alignment of the dispenser 15 and control of the amount of coating resin 16 dispensed, which lengthens the time required for the coating resin 16 application process. Furthermore, if low-precision alignment and control of the amount of coating resin 16 are used to complete the application process in a short time, the dispenser 15 may be misaligned, resulting in problems such as the light-emitting surface of the light-emitting element chip 2 being coated with the coating resin 16 or a portion of the conductive member 11 being exposed without being coated.

[0016] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a reflective optical semiconductor device in which a conductive member is reliably and simply covered, and a method for manufacturing the same.

[0017] a light-receiving element chip including a light-emitting element, a light-receiving element electrode, a light-emitting element wiring connected to the light-emitting element electrode, and a through hole in which the light-emitting element chip is disposed; and a mounting portion in which a mounting portion electrode connected to any of the light-emitting element electrode, the light-receiving element electrode, and the light-emitting element wiring is disposed, wherein the light-receiving element chip has the light-receiving element electrode and the light-emitting element wiring disposed on its light-receiving surface and is mounted on the mounting portion by an insulating member; the light-emitting element chip has the light-emitting element electrodes disposed on its light-emitting surface and mounting surface, respectively, and the light-emitting element electrodes on the mounting surface are connected to the mounting portion electrodes disposed in the through holes by conductive members and are mounted on the mounting portion; the conductive member is covered by the insulating member that mounts the light-receiving element chip on the mounting portion; the light-emitting element electrode on the light-emitting surface of the light-emitting element chip is connected to the light-emitting element wiring by metal wires, and the light-receiving element electrode and the light-emitting element wiring are each connected to the mounting portion electrodes by metal wires.

[0018] A method of manufacturing a reflective optical semiconductor device according to another aspect of the present invention includes a first step of mounting a light-emitting element chip, the light-emitting element chip having a light-emitting element and light-emitting element electrodes on a light-emitting surface and a mounting surface, on the mounting part by connecting the light-emitting element electrodes disposed on the mounting surface to the mounting part electrodes of the mounting part with a conductive member; a second step of applying an insulating member to an area of ​​the mounting part where the light-receiving element chip will be disposed; a third step of placing the light-receiving element chip, the light-receiving element chip having a light-receiving element, a light-receiving element electrode, light-emitting element wiring connected to the light-emitting element electrode, and a through hole, on the mounting part to which the insulating member has been applied so that the light-emitting element chip is disposed in the through hole; The method includes a fourth step of pressing the insulating member with an element chip, extruding the insulating member from between the light-receiving element chip and the mounting portion, and covering the conductive member exposed in the through hole with the extruded insulating member; a fifth step of hardening the insulating member and mounting the light-receiving element chip to the mounting portion; and a sixth step of connecting, with metal wires, the light-emitting element electrode arranged on the light-emitting surface of the light-emitting element chip, the light-emitting element wiring arranged on the light-receiving surface of the light-receiving element chip, the light-emitting element wiring, and the light-receiving element electrode arranged on the light-receiving surface of the light-receiving element chip to the mounting portion electrode.

[0019] According to the reflective optical semiconductor device of the present invention, the conductive member is reliably covered by the insulating member, and the light-emitting surface of the light-emitting element chip is not covered by the insulating member, making it possible to provide a reflective optical semiconductor device with excellent directional characteristics and high reliability.Furthermore, according to the manufacturing method of the reflective optical semiconductor device of the present invention, the insulating member is pushed out by pressing the insulating member with the light-receiving element chip, and the conductive member can be covered by the pushed-out insulating member, making it possible to simply manufacture a reflective optical semiconductor device with excellent directional characteristics and high reliability.

[0020] FIG. 10 is an explanatory diagram of one embodiment (embodiment 1) of a reflective optical semiconductor device according to one aspect of the present invention. FIG. 11 is a cross-sectional schematic diagram of the reflective optical semiconductor device of FIG. 1. FIG. 12 is a diagram illustrating the directional characteristics of a light-emitting element arranged in a light-emitting element chip of embodiment 1. FIG. 13 is an explanatory diagram of one embodiment of a first step of a method for manufacturing a reflective optical semiconductor device according to another aspect of the present invention. FIG. 14 is an explanatory diagram of one embodiment of a second step of a method for manufacturing a reflective optical semiconductor device according to another aspect of the present invention. FIG. 15 is an explanatory diagram of one embodiment of a third step of a method for manufacturing a reflective optical semiconductor device according to another aspect of the present invention. FIG. 16 is an explanatory diagram of one embodiment of a fourth step of a method for manufacturing a reflective optical semiconductor device according to another aspect of the present invention. FIG. 17 is an explanatory diagram showing an example of a reflective optical semiconductor device. FIG. 18 is an explanatory diagram showing another example of a reflective optical semiconductor device. FIG. 19 is a cross-sectional schematic diagram illustrating a method for applying a coating resin in the reflective optical semiconductor device of FIG.

[0021] Next, embodiments of the reflective optical semiconductor device of the present invention and implementations of the manufacturing method thereof will be described with reference to the drawings, but the present invention is not limited to these embodiments and implementations, and the members, materials, etc. described below can be variously modified within the scope of the spirit of the present invention. Furthermore, in the drawings, the same symbols indicate equivalent or identical items, and the size and positional relationship between each component are for convenience and may not strictly reflect the actual situation.

[0022] (Reflective Optical Semiconductor Device) First, an embodiment of a reflective optical semiconductor device will be described as one aspect of the present invention. FIG. 1 is an explanatory diagram of one embodiment (Embodiment 1) of the reflective optical semiconductor device of the present invention, and FIG. 2 is a schematic cross-sectional view of the reflective optical semiconductor device of Embodiment 1 shown in FIG. 1, corresponding to a cross-sectional view in the left-right direction of the drawing passing through the centers of the light-emitting element chip 2, the light-emitting element wiring 9, and the mounting portion electrode 13C in FIG. 1. As shown in FIGS. 1 and 2, the reflective optical semiconductor device of this embodiment is configured such that a light-receiving element chip 1 having a through-hole 14 and a light-emitting element chip 2 arranged in the through-hole 14 are mounted on a mounting portion 3. A light-receiving element array 5 consisting of a plurality of light-receiving elements 4 is arranged on the light-receiving element chip 1. The light-receiving elements 4 can be composed of, for example, photodiodes. The cathode or anode of the photodiode is connected to a light-receiving element electrode 6 arranged on the upper surface (light-receiving surface) of the light-receiving element chip 1 by wiring or the like not shown.

[0023] A light-emitting element is disposed on the light-emitting element chip 2. The light-emitting element can be, for example, a light-emitting diode. A light-emitting portion 7 that emits light and a light-emitting element electrode 8 connected to the cathode of the light-emitting diode are disposed on the upper surface (light-emitting surface) of the light-emitting element chip 2, and a light-emitting element electrode 8A connected to the anode of the light-emitting diode is disposed on the lower surface (mounting surface) of the light-emitting element chip 2. The light-emitting element electrode 8 is connected to a light-emitting element wiring 9 disposed on the light-receiving surface of the light-receiving element chip 1 by a metal wire 10. The metal wire 10 is formed in a position and shape that does not block the light emitted from the light-emitting portion 7 of the light-emitting element chip 2. For example, the metal wire 10 is formed so as not to be disposed in an area within an emission angle of ±60°. The light-emitting element electrode 8A disposed on the mounting surface of the light-emitting element chip 2 is connected to a mounting portion electrode 13C disposed in the through-hole 14 by a conductive member 11 such as silver paste, and the light-emitting element chip 2 is mounted on the mounting portion 3.

[0024] 1, the mounting portion electrodes 13C are configured so that a portion thereof is exposed on the mounting portion 3, and continues into the through-holes 14, with ends thereof being larger than the mounting surface of the light-emitting element chip 2 and disposed within the through-holes 14. The mounting portion electrodes 13C configured in this manner are connected to the light-emitting element electrodes 8A on the mounting surface of the light-emitting element chip 2 by conductive members 11. As shown in FIG. 1, the mounting portion electrodes 13C are disposed below the light-receiving element chip 1, and therefore the light-receiving element chip 1 is mounted on the mounting portion 3 by being adhered onto the mounting portion 3 and portions of the mounting portion electrodes 13C by insulating members 12 which serve as adhesive.

[0025] The conductive member 11 is susceptible to sulfuration and migration due to the influence of the outside air, and is therefore not preferably exposed to the outside air. Therefore, as shown in Figure 2, the light-receiving element chip 1 is mounted on the mounting section 3, which is made of, for example, an organic substrate, by bonding it to a part of the mounting section electrode 13C with an insulating member 12, and the insulating member 12 is further configured to cover the conductive member 11.

[0026] In this configuration, the insulating member 12 is selected from a material that functions as an adhesive for bonding the light-receiving element chip 1 and the mounting portion 3, while also functioning as a coating material for the conductive member 11. For example, the insulating member 12 can be selected from epoxy resin, phenolic resin, polyimide, etc. In particular, when the conductive member is a material containing silver, such as silver paste, it is preferable to select a material that is impermeable to sulfide gas to prevent the silver from sulfiding. Specifically, a fluororesin is preferred that is impermeable to sulfide gas, has viscosity that changes shape to coat the conductive member 11, and has the quick-drying and heat-resistance required for the manufacturing process and for a reflective optical semiconductor device, and has a non-sticky surface that does not attract dust or dirt after curing.

[0027] The insulating member 12 is applied in a paste state, dried, and hardened, and the light-receiving element chip 1 is adhered and mounted on the mounting portion 3. Typically, in a reflective optical sensor, it is preferable to configure the distance from the light-emitting element to the reflector equal to the distance from the reflector to the light-receiving element, thereby improving sensing accuracy. Therefore, it is preferable that the heights of the light-receiving surface of the light-receiving element chip 1 and the light-emitting element chip 2 provided in the reflective optical semiconductor device when mounted on the mounting portion 3 are the same (in other words, the height-wise positions of the top surfaces of the light-receiving element chip 1 and the light-emitting element chip 2 are the same). It is preferable that the light-receiving element chip 1 and the light-emitting element chip 2 are mounted so that the difference in height between the top surfaces of the light-receiving element chip 1 and the light-emitting element chip 2 is at least 40 μm or less.

[0028] Mounting section electrodes 13 are arranged on the mounting section 3, and each mounting section electrode 13 is connected to either the light receiving element electrode 6 or the light emitting element wiring 9 by a metal wire 10. The metal wire 10 connecting either the light receiving element electrode 6 or the light emitting element wiring 9 to the mounting section electrode 13 may be sealed with, for example, epoxy resin or the like.

[0029] As described above, the reflective optical semiconductor device of this embodiment is configured so that the conductive member 11 in the through hole 14 is covered by the insulating member 12 that mounts the light-receiving element chip 1 on the mounting portion 3. Therefore, as described in Fig. 11 , there is no need to cover the conductive member 11 with the coating resin 16 that is discharged into the through hole 14 from the dispenser 15 that is arranged on the light-emitting surface side of the light-emitting element chip 2, and there is no risk that the light-emitting surface of the light-emitting element chip 2 will be covered with the coating resin 16. Therefore, in the reflective optical semiconductor device of this embodiment, the light-emitting surface of the light-emitting element chip 2 is exposed without being covered with a coating resin or the like, and light emitted from the light-emitting element chip 2 is not diffused, resulting in a reflective optical semiconductor device with good directivity symmetry and excellent directional characteristics with a narrow beam angle.

[0030] FIG. 3 is a directional characteristic diagram showing the directional characteristics of the light-emitting element disposed on the light-emitting element chip 2 in the reflective optical semiconductor device of embodiment 1 shown in FIG. The directional characteristic diagram shown in FIG. 3 is a diagram showing the spread of light emitted from the center of the light-emitting portion 7 as relative brightness (relative luminous intensity) for each angle. The numbers on the circumference of the semicircle indicate the angle of the emitted light, and the straight line representing the radius of the semicircle indicates the relative luminous intensity, with the brightness of the brightest part being shown as 100% relative luminous intensity. In FIG. 3, the directional characteristic of the light-emitting element of this embodiment, in which the light-emitting surface of the light-emitting element chip is not coated with a resin, is shown by a solid line, while the directional characteristic of a light-emitting element of a comparative example, in which the light-emitting surface of the light-emitting element chip is coated with a resin coating, is shown by a dashed line. As shown in FIG. 3, it can be seen that the light-emitting element of this embodiment has better directional symmetry, a narrower directional angle, and superior directional characteristics than the comparative example.

[0031] (Method for Manufacturing a Reflective Optical Semiconductor Device) Next, an embodiment of a method for manufacturing a reflective optical semiconductor device will be described as another aspect of the present invention. FIGS. 4 to 7 are explanatory diagrams of one embodiment of a method for manufacturing a reflective optical semiconductor device of the present invention. Like FIG. 2, these diagrams correspond to cross-sectional views taken in the left-right direction of the drawing, passing through the centers of the light-emitting element chip 2, light-emitting element wiring 9, and mounting portion electrode 13C of the reflective optical semiconductor device shown in FIG. 1. First, as shown in FIG. 4, a mounting portion 3 such as an organic substrate on which mounting portion electrodes 13 and 13C are formed is prepared. The light-emitting element chip 2 is mounted on the mounting portion electrode 13C of the mounting portion 3 on which the reflective optical semiconductor device is formed using a conductive member 11. The light-emitting element chip 2 can be composed of, for example, a light-emitting diode. A light-emitting portion 7 that emits light and a light-emitting element electrode 8 connected to the cathode of the light-emitting diode are arranged on the upper surface (light-emitting portion) of the light-emitting element chip 2, and a light-emitting element electrode 8A connected to the anode of the light-emitting diode is arranged on the lower surface (mounting surface) of the light-emitting element chip 2. The light-emitting element electrode 8A is connected to the mounting portion electrode 13C using a conductive member 11 such as silver paste, and the light-emitting element chip 2 is mounted on the mounting portion 3.

[0032] Next, as shown in Fig. 5, an insulating member 12 is applied using a dispenser or the like to the mounting portion 3 on which the light-emitting element chip 2 is mounted and the region of the mounting portion electrode 13C where the light-receiving element chip will be disposed. The thickness of the applied insulating member 12 is preferably such that when the light-receiving element chip is placed on the insulating member 12, the height-wise position of the upper surface (light-receiving surface) of the light-receiving element chip is higher than the height-wise position of the upper surface (light-emitting surface) of the light-emitting element chip 2. Furthermore, in a process described below, the conductive member 11 is covered with the insulating member 12, so the thickness of the insulating member 12 in the region surrounding the through-hole when the light-receiving element chip is mounted is set to a thickness that includes the insulating member 12 necessary to cover the conductive member 11.

[0033] Next, as shown in FIG. 6 , the light-receiving element chip 1 is placed on the insulating member 12. As shown in FIG. 1 , a light-receiving element array 5 composed of a plurality of light-receiving elements 4 is arranged on the upper surface (light-receiving surface) of the light-receiving element chip 1. The light-receiving elements 4 may be composed of, for example, photodiodes. Light-receiving element electrodes 6 connected to the cathodes or anodes of the photodiodes are arranged on the light-receiving surface of the light-receiving element chip 1. Light-emitting element wiring 9 connected to light-emitting element electrodes 8 is also arranged on the light-receiving surface of the light-receiving element chip 1. The light-receiving element chip 1 also has through-holes 14, and the light-receiving element chip 1 is placed on the insulating member 12 so that the light-emitting element chips 2 are arranged in the through-holes 14. At this time, it is preferable that the height position of the upper surface of the light-receiving element chip 1 be higher than the height position of the upper surfaces of the light-emitting element chips 2.

[0034] Next, as shown in FIG. 7 , pressure is applied from the top surface of the light-receiving element chip 1, and the light-receiving element chip 1 presses the insulating member 12, thereby applying pressure to the insulating member 12. At this time, the insulating member 12 is in a fluid state before hardening. As a result, the insulating member 12 is extruded outward from between the light-receiving element chip 1 and the mounting portion 3, etc. The insulating member 12 extruded into the through-hole 14 covers the surface of the conductive member 11. If, after pressing the light-receiving element chip 1, the height position of the top surface of the light-receiving element chip 1 is the same as the height position of the top surface of the light-emitting element chip 2, when used as a reflective optical sensor, the distance from which light emitted from the light-emitting element of the light-emitting element chip 2 reaches the reflector is equal to the distance from the reflector from the reflector to the light-receiving element of the light-receiving element chip 1, which is preferable from the perspective of sensing accuracy. In this way, it is preferable that the height position of the upper surface of the light-receiving element chip 1 and the height position of the upper surface of the light-emitting element chip 2 are the same, but it is preferable that they are mounted so that the difference in height between the height position of the upper surface of the light-receiving element chip 1 and the height position of the upper surface of the light-emitting element chip 2 is at least 40 μm or less. Note that in Figure 7, the thickness of the light-emitting element wiring 9 and the light-emitting element electrode 8 is about 1 μm or less, while the thickness of the light-receiving element chip 1 and the light-emitting element chip 2 is more than 300 μm, and the thickness of the light-emitting element wiring 9 and the light-emitting element electrode 8 is so thin that it can be ignored. There is no problem if the height position of the upper surface of the light-receiving element chip 1 is lower than the height position of the upper surface of the light-emitting element chip 2.

[0035] Thereafter, the insulating member 12 is dried and hardened in a thermostatic oven, and the light-receiving element chip 1 is mounted on the mounting portion 3 .

[0036] By forming the insulating member 12 in the above manner, the conductive member 11 connecting the light-emitting element electrode 8A of the light-emitting element chip 2 to the mounting portion electrode 13C is covered with the insulating member 12. In this configuration, the insulating member 12 functions as both an adhesive for bonding the light-receiving element chip 1 and the mounting portion 3 and as a coating for the conductive member 11, so it is selected from materials that have both functions. For example, the insulating member 12 can be selected from epoxy resin, phenolic resin, polyimide, etc. In particular, when the conductive member is a material containing silver, such as silver paste, it is preferable to select a material that is impermeable to sulfuric gas to prevent the silver from sulfiding. Specifically, a fluororesin is preferred that is impermeable to sulfuric gas, has viscosity that changes shape to cover the conductive member 11, and has the quick-drying and heat resistance required for the manufacturing process and for a reflective optical semiconductor device, and has a non-adhesive surface that does not attract dust or dirt after curing.

[0037] The light-emitting element electrode 8 is connected by a metal wire 10 to the light-emitting element wiring 9 arranged on the light-receiving surface of the light-receiving element chip 1. The metal wire 10 is formed in a position and shape that does not block the light emitted from the light-emitting portion 7 of the light-emitting element chip 2. For example, the metal wire 10 is formed so as not to be arranged in an area within a light-emitting angle of ±60°. By arranging the metal wire 10 in this manner, the light emitted from the light-emitting portion 7 is not blocked by the metal wire 10, and deterioration of the directional characteristics caused by the metal wire 10 can be prevented.

[0038] The light-receiving element electrode 6 and the light-emitting element wiring 9 are connected to each mounting portion electrode 13 arranged on the mounting portion 3 by metal wires 10, thereby forming the reflective optical semiconductor device shown in Fig. 1. The metal wires 10 connecting either the light-receiving element electrode 6 or the light-emitting element wiring 9 to the mounting portion electrode 13 may be sealed with, for example, epoxy resin or the like.

[0039] As described above, the method for manufacturing a reflective optical semiconductor device of this embodiment can coat the conductive member 11 without using a method such as discharging a coating resin into the through-hole 14 from a dispenser arranged on the light-emitting surface side of the light-emitting element chip 2, as described with reference to Fig. 11. Therefore, the light-emitting surface of the light-emitting element chip 2 is not covered with a coating resin, and light emitted from the light-emitting element chip 2 is not diffused, so a reflective optical semiconductor device can be easily formed that has good directivity symmetry and excellent directional characteristics with a narrow directivity angle. Furthermore, the conductive resin 11 can be reliably coated, so a highly reliable reflective optical semiconductor device can be easily formed.

[0040] Although the reflective optical semiconductor device and the manufacturing method thereof according to the present invention have been described above, it goes without saying that the present invention is not limited to the above-described embodiments and implementations.

[0041] (Summary) (1) One embodiment of a reflective optical semiconductor device according to the present invention is a reflective optical semiconductor device comprising: a light-emitting element chip including a light-emitting element and a light-emitting element electrode; a light-receiving element chip including a light-receiving element, a light-receiving element electrode, light-emitting element wiring connected to the light-emitting element electrode, and a through-hole in which the light-emitting element chip is disposed; and a mounting portion in which a mounting portion electrode connected to any of the light-emitting element electrode, the light-receiving element electrode, and the light-emitting element wiring is disposed; the light-receiving element chip has the light-receiving element electrode and the light-emitting element wiring disposed on its light-receiving surface and is mounted on the mounting portion by an insulating member; the light-emitting element chip has the light-emitting element electrodes disposed on its light-emitting surface and mounting surface, respectively, and the light-emitting element electrodes on the mounting surface are connected to the mounting portion electrodes disposed in the through-holes by conductive members and are mounted on the mounting portion; the conductive member is covered by the insulating member that mounts the light-receiving element chip on the mounting portion; the light-emitting element electrode on the light-emitting surface of the light-emitting element chip is connected to the light-emitting element wiring by metal wires; and the light-receiving element electrode and the light-emitting element wiring are each connected to the mounting portion electrode by metal wires.

[0042] According to the reflective optical semiconductor device of the embodiment (1) above, the conductive member is reliably covered by the insulating member, and the light-emitting surface of the light-emitting element chip is not covered by a coating resin or the like, making it possible to provide a reflective optical semiconductor device with excellent directional characteristics and high reliability.

[0043] (2) According to another embodiment, in the reflective optical semiconductor device of (1) above, the conductive member contains silver, and the insulating member is made of a material that is impermeable to sulfur gas.

[0044] According to the reflective optical semiconductor device of the above embodiment (2), sulfurization of the conductive member containing silver can be prevented, and a highly reliable reflective optical semiconductor device can be provided.

[0045] (3) One embodiment of a method for manufacturing a reflective optical semiconductor device, which is another aspect of the present invention, includes a first step of mounting a light-emitting element chip, which includes a light-emitting element and light-emitting element electrodes on a light-emitting surface and a mounting surface, on the mounting part by connecting the light-emitting element electrodes arranged on the mounting surface to the mounting part electrodes of the mounting part with a conductive member; a second step of applying an insulating member to an area of ​​the mounting part where the light-receiving element chip is to be arranged; and a third step of placing the light-receiving element chip, which includes a light-receiving element, a light-receiving element electrode, light-emitting element wiring connected to the light-emitting element electrode, and a through hole, on the mounting part to which the insulating member has been applied so that the light-emitting element chip is arranged in the through hole. a fourth step of pressing the insulating member with the light-receiving element chip, extruding the insulating member from between the light-receiving element chip and the mounting portion, and covering the conductive member exposed in the through hole with the extruded insulating member; a fifth step of hardening the insulating member and mounting the light-receiving element chip on the mounting portion; and a sixth step of connecting, with metal wires, the light-emitting element electrode arranged on the light-emitting surface of the light-emitting element chip, the light-emitting element wiring arranged on the light-receiving surface of the light-receiving element chip, the light-emitting element wiring, and the light-receiving element electrode arranged on the light-receiving surface of the light-receiving element chip and the mounting portion electrode.

[0046] According to the manufacturing method of the reflective optical semiconductor device of the embodiment (3) above, the insulating member is extruded by pressing with the light-receiving element chip, and the conductive member can be covered with the extruded insulating member, making it possible to easily manufacture a reflective optical semiconductor device with excellent directional characteristics and high reliability.

[0047] (4) According to another embodiment, in the method for manufacturing a reflective optical semiconductor device of (3) above, the conductive member contains silver, and the insulating member is made of a material that is impermeable to sulfur gas.

[0048] According to the manufacturing method for a reflective optical semiconductor device of the embodiment (4) above, sulfurization of the conductive member containing silver can be prevented, and a highly reliable reflective optical semiconductor device can be provided.

[0049] (5) According to another embodiment, in the manufacturing method of the reflective optical semiconductor device of (3) or (4) above, the pressing of the insulating member by the light receiving element chip in the fourth step is performed until the height position of the upper surface of the light receiving element chip coincides with the height position of the upper surface of the light emitting element chip.

[0050] According to the manufacturing method of the reflective optical semiconductor device of the embodiment (5) above, the distance from the light emitted from the light-emitting element to the reflector and the distance from the reflector to the light-receiving element can be made equal, and a reflective optical semiconductor device that constitutes a reflective optical sensor with improved sensing accuracy can be provided.

[0051] (6) According to yet another embodiment, in the manufacturing method of the reflective optical semiconductor device of (3) or (4) above, the metal wire connecting the light-emitting element electrode and the light-emitting element wiring in the sixth step is configured to be positioned so as not to block the light emitted from the light-emitting element.

[0052] According to the manufacturing method of the reflective optical semiconductor device of the embodiment (6) above, the light emitted from the light emitting portion is not blocked by the metal wire, and deterioration of the directional characteristics caused by the metal wire can be prevented.

[0053] DESCRIPTION OF SYMBOLS 1, 1A, 1B Light receiving element chip 2 Light emitting element chip 3, 3A, 3B Mounting portion 4 Light receiving element 5 Light receiving element array 6 Light receiving element electrode 7 Light emitting portion 8, 8A Light emitting element electrode 9, 9A Light emitting element wiring 10 Metal wire 11 Conductive member 12 Insulating member 13, 13A, 13B, 13C Mounting portion electrode 14 Through hole 15 Dispenser 16 Coating resin

Claims

1. A reflective optical semiconductor device comprising: a light-emitting element chip including a light-emitting element and a light-emitting element electrode; a light-receiving element chip including a light-receiving element, a light-receiving element electrode, a light-emitting element wiring connected to the light-emitting element electrode, and a through hole in which the light-emitting element chip is disposed; and a mounting portion in which a mounting portion electrode connected to any of the light-emitting element electrode, the light-receiving element electrode, and the light-emitting element wiring is disposed, wherein the light-receiving element chip has the light-receiving element electrode and the light-emitting element wiring disposed on its light-receiving surface and is mounted on the mounting portion by an insulating member; the light-emitting element chip has the light-emitting element electrode disposed on its light-emitting surface and mounting surface, respectively, and the light-emitting element electrode on the mounting surface is connected to the mounting portion electrode disposed in the through hole by a conductive member and is mounted on the mounting portion, the conductive member being covered by the insulating member that mounts the light-receiving element chip to the mounting portion; the light-emitting element electrode on the light-emitting surface of the light-emitting element chip is connected to the light-emitting element wiring by a metal wire, and the light-receiving element electrode and the light-emitting element wiring are each connected to the mounting portion electrode by a metal wire.

2. The reflective optical semiconductor device according to claim 1, wherein said conductive member contains silver, and said insulating member is made of a material that is impermeable to sulfur gas.

3. A first step of mounting a light-emitting element chip, which includes a light-emitting element and a light-emitting element electrode on its light-emitting surface and mounting surface, on the mounting section by connecting the light-emitting element electrode arranged on the mounting section to the mounting section electrode of the mounting section with a conductive member; a second step of applying an insulating member to an area of ​​the mounting section where the light-receiving element chip will be arranged; a third step of placing the light-receiving element chip, which includes a light-receiving element, a light-receiving element electrode, a light-emitting element wiring connected to the light-emitting element electrode, and a through hole, on the mounting section to which the insulating member has been applied, such that the light-emitting element chip is arranged within the through hole; a fourth step of pressing the insulating member with the light-receiving element chip to push out the insulating member from between the light-receiving element chip and the mounting section, and covering the conductive member exposed in the through hole with the pushed-out insulating member; and a fifth step of hardening the insulating member and mounting the light-receiving element chip on the mounting section. a sixth step of connecting, by metal wires, the light-emitting element electrode arranged on the light-emitting surface of the light-emitting element chip, the wiring for the light-emitting element arranged on the light-receiving surface of the light-receiving element chip, the wiring for the light-emitting element, and the light-receiving element electrode arranged on the light-receiving surface of the light-receiving element chip and the mounting portion electrode.

4. The method for manufacturing a reflective optical semiconductor device according to claim 3, wherein the conductive member contains silver, and the insulating member is made of a material that is impermeable to sulfur gas.

5. A method for manufacturing a reflective optical semiconductor device as claimed in claim 3 or 4, wherein the pressing of the insulating member by the light-receiving element chip in the fourth step is continued until the height position of the upper surface of the light-receiving element chip coincides with the height position of the upper surface of the light-emitting element chip.

6. A method for manufacturing a reflective optical semiconductor device as set forth in claim 3 or 4, wherein the metal wire connecting the light-emitting element electrode and the light-emitting element wiring in the sixth step is positioned so as not to block light emitted from the light-emitting element.

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