JPH0832106A - Optical semiconductor device and substrate mounting device - Google Patents

Abstract

PURPOSE:To accurately mount an optical semiconductor device which communicates with a circuit formed on a wiring board on the wiring board by aligning the optical axis of a light emitting section coincident with that of a light receiving section and directing the light emitting surface of the light emitting section and the light receiving surface of the light receiving section in the opposite directions. CONSTITUTION:The front ends of external leads 251 and 252 which are horizontally lead out from the package of an optical semiconductor device 20 and bent in easily connectable states are soldered to wiring 12. Since the center of the package is coincident with an optical axis positioned to the center of a through hole 11, a lens 241 for light emitting element formed at the center of the package is inserted into through light 11. On the opposite side of the lens 241 at the center of the package, a lens 242 for light receiving element is formed. Therefore, the optical semiconductor device 20 fitted to a wiring board 10 in such a way can make optical communication with a circuit formed on the upper or lower surface of a wiring board 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical semiconductor device including a light emitting element and a light receiving element for performing optical space transmission over a short distance without using an optical fiber, and a substrate mounting apparatus mounting the same. .

[0002]

2. Description of the Related Art As the reliability of optical communication technology increases, the development and application of optical semiconductor devices used in this technology are progressing. In particular, a circuit formed on each wiring board by mounting the optical semiconductor device on a wiring board such as a printed circuit board, facing it with the wiring board also mounting the optical semiconductor device, and connecting two semiconductor devices with an optical signal. There is an electrical connection between them. By changing the communication between the circuits of the conventional wiring board from the conventional electric signal to the optical signal, it is possible to cope with the wiring resistance with a low resistance for the integrated circuit which is speeded up.

A conventional board mounting apparatus in which a conventional optical semiconductor device is mounted on a wiring board will be described with reference to FIGS.
As shown in FIG. 18, the wiring board 50 is formed of, for example, a printed wiring board, and an optical semiconductor device 60 such as an optical space transmitter or an optical space receiver is mounted thereon. The optical semiconductor device 60 includes an external lead 65 that is horizontally led out from the side surface of the package and electrically connected to an optical semiconductor element inside the package. The external lead 65 is
Wiring pattern (not shown) formed on the wiring board 50
It is electrically connected to, for example, by soldering. The external lead 65 is drawn out horizontally, then once bent downward, and again bent horizontally at the tip. And the tip part is connected to the wiring pattern. Therefore, the package is supported by the external leads 65 and floats in the air. That is, the package bottom surface is separated from the wiring board surface. 19A is a plan view of the optical semiconductor device 60 mounted on a wiring board, FIG. 19B is a side view from the arrow D direction, and FIG. 19C is a side view of FIG. 19A. C-C '
It is sectional drawing of the part which follows a line.

As shown in FIGS. 19A and 19B, the package 64 is composed of a resin encapsulant made of a translucent resin such as an epoxy resin. A pair of external leads 65 are led out from two opposite sides of the package 64. A dome-shaped lens portion 641 made of the same material as the package body is formed on the upper portion of the package 64, and the optical axis of the optical semiconductor element inside the package 64 is formed in the direction perpendicular to the center of the lens. Further, in FIG. 19C, an optical semiconductor element 62 such as a light receiving element or a light emitting element is horizontally mounted on the element mounting portion 61, and its optical axis is formed perpendicular to the optical semiconductor element 62. There is. The light emitting element is a light emitting diode (LED).
t Emitting Diode) and laser diode (LD)
e) and the like are used, and a photo diode (PD) is usually used as a light receiving element. The inner lead 66, which is continuously connected to the outer lead 65, is opposed to the optical semiconductor element 62 while being separated from the element mounting portion 61, and its tip has a bonding wire 63 such as an Au wire.
Is electrically connected to an electrode pad (not shown) formed on the surface of the optical semiconductor element 62. The element mounting portion 61, the optical semiconductor element 62, the bonding wire 63, and the internal lead 66 are formed of a transparent resin package 64.
It is molded.

Dome type lens portion 641 of the package 64
Is formed in the upper part of the central portion of the optical semiconductor element 62, and the light generated in the element 62 is emitted from here. The optical axis is formed in the vertical direction at a right angle to the element mounting portion 61 and the optical semiconductor element 62 which are arranged horizontally. Element mounting part 6
1, the outer leads 65 and the inner leads 66 are usually formed from an integrated lead frame. Figure 2
FIGS. 0 (a) and 20 (b) are cross-sectional views of a board mounting device for explaining optical space transmission performed by two sets or three sets or more of wiring boards on which a conventional optical semiconductor device is mounted. Figure 20 (a)
In the first wiring board 51, the optical space transmitter 60
3 and the optical space receiver 600 are mounted. Also the second
An optical space transmitter 601 and an optical space receiver 602 are mounted on the wiring board 52 of FIG. The two wiring boards face each other to form two optical axes composed of a pair of transceivers. An integrated circuit having a predetermined function is formed on each wiring board. For example, when the first wiring board 51 is a master unit having an operation function, the second wiring board 52 has a combination of operated slave units, and
There is a case where the first wiring board 51 is used as a first calculator and the second wiring board is used as a second calculator. Further, in order to increase the directivity of the light emitting element, a lens having high directivity may be selected.

In FIG. 20B, a third wiring board 53 is inserted and arranged between the first and second wiring boards 51 and 52. On the third wiring board 53, two sets of transmitters / receivers 604 to 607 mounted back to back on both sides of the board are formed. This is an example in which wiring boards are connected to each other when one circuit device is configured by these three wiring boards.

[0007]

In the past, signals were often exchanged between a pair of wiring boards. However, as the circuit device becomes complicated, one circuit board as described above should exchange signals. In many cases, three or more substrates are included. As described above, the conventional board mounting device is
Since the transmitter and the receiver formed on a plurality of wiring boards are combined and arranged on the optical axis, it is difficult to accurately arrange the optical semiconductor devices on the two sets of optical axes.
If the accuracy was low, there were problems such as poor transmission. Further, in the case of communicating between three or more wiring boards, the wiring board requires double-sided mounting to perform double-sided wiring, which has a drawback of increasing cost. Further, when connecting the wiring boards at both ends of the three wiring boards by an optical signal, an opening is formed in the peripheral portion of the optical axis of the intermediate wiring board, and an optical connection is made between the wiring boards at both ends through the opening. Was going on.

The present invention has been made under such circumstances, and a semiconductor device for communication between wiring boards which receives and transmits an optical signal along one optical axis and between three or more wiring boards is provided. The optical semiconductor device that communicates between the wiring boards can be mounted on the wiring boards with high accuracy even when communicating with each other, and the wiring board has one side even when communicating with three or more wiring boards. It is an object of the present invention to provide a board mounting device which can be mounted on one side of wiring and can be formed at low cost.

[0009]

SUMMARY OF THE INVENTION An optical semiconductor device of the present invention includes a light emitting element having a light emitting portion for emitting light to the outside, a light receiving element having a light receiving portion for receiving light from the outside, and an electric signal of an external circuit. A first lead for transmitting to the light emitting element, a second lead for transmitting an optical signal from the light receiving section to an external circuit as an electric signal, a light emitting element, the light receiving element, and one end of the first lead And a part including the one end of the second lead are covered, and at least a region covering the light emitting part and the light receiving part is provided with a transparent resin mold package, and the optical axis of the light emitting part and the light receiving part are provided. It is characterized in that they coincide with the optical axis, and that the light emitting surface of the light emitting portion and the light receiving surface of the light receiving portion face in opposite directions. A lens is mounted on one of the light emitting surface of the light emitting portion and the light receiving surface of the light receiving portion or the light receiving surface and the light emitting surface such that the optical axis is in the center thereof. It may be formed integrally with. Each of the light emitting element and the light receiving element has two, and the resin mold package has a first optical axis composed of the first light emitting element and the first light receiving element, and a second optical axis. It is also possible to have a second optical axis composed of the light emitting element and the second light receiving element. The light emitting direction of the first light emitting element may be opposite to the light emitting direction of the second light emitting element.

The board mounting apparatus of the present invention has a through hole,
A plurality of wiring boards arranged and stacked at intervals, and an optical semiconductor device mounted on the wiring board and arranged so that an optical axis passes through the inside of the through hole, the optical semiconductor device includes: A light emitting element having a light emitting portion that emits light to the outside,
A light receiving element having a light receiving section for receiving light from the outside, a first lead for transmitting an electric signal of an external circuit to the light emitting element, and a second lead for transmitting an optical signal from the light receiving section to the external circuit as an electric signal. And the light emitting element, the light receiving element, a part including one end of the first lead and a part including one end of the second lead, and at least a region covering the light emitting part and the light receiving part is transparent. A resin mold package that is, the optical axis of the light emitting unit and the optical axis of the light receiving unit are aligned, and the light emitting surface of the light emitting unit and the light receiving surface of the light receiving unit are in opposite directions. It is characterized by facing. In the optical semiconductor device, a lens is attached such that the optical axis is located at the center of the light emitting surface of the light emitting portion and the light receiving surface of the light receiving portion or the light receiving surface and the light emitting surface. The lens may be integrally molded with the resin mold package.

[0011]

The wiring substrate is provided with a through hole through which the optical axis passes, the light receiving element and the light emitting element are arranged in the optical semiconductor device so that the optical axes coincide with each other, and the light emitting surface of the light emitting element and the light receiving surface of the light receiving element. By arranging and so as to face in mutually opposite directions, when communicating between three or more wiring boards, it is possible to easily communicate without mounting the intermediate wiring board on both sides. Further, in the optical semiconductor device, since a pair of upper and lower light emitting elements / light receiving elements are arranged in parallel and resin-molded, the accuracy between the optical axes is improved and the number of parts is reduced.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. First, a first embodiment will be described with reference to FIGS. 1 is a cross-sectional view of a substrate mounting device on which the optical semiconductor device of the present invention is mounted, FIG. 2A is a plan view seen from above the optical semiconductor device, and FIG. 2B is FIG. 2A. 2A is a side view of the optical semiconductor device viewed from the direction A in FIG.
2 is a cross-sectional view of a portion taken along the line BB ′ of FIG.
FIG. 4A is a plan view of a light emitting element portion inside a package of an optical semiconductor device, and FIG. 5 is a plan view of a light receiving element portion inside a package of an optical semiconductor device. 6 and 6 are cross-sectional views of a board mounting device in which an optical semiconductor device is mounted on a plurality of wiring boards.

In FIG. 1, the wiring board 10 has a through hole 11
The wiring 12 is formed on the front surface (back side of the drawing) of the substrate to which electronic components (not shown) around it are attached. The optical axis of the optical semiconductor device 20 is the through hole 11
It is implemented while passing through the inside. That is, the tips of the external leads 25, which are drawn out horizontally from the package 24 of the optical semiconductor device 20 and bent for easy connection, are the wirings 1.
Soldered to 2. Since the center of the package 24 is along the optical axis arranged at the center of the through hole 11, the light emitting element lens 2 formed at the center of the package 24
41 is inserted into the through hole 11. Same package 2
A light receiving element lens 242 is formed on the opposite side of the light emitting element lens 241 at the center of 4. The optical semiconductor device 20 thus mounted on the wiring board 10 is
Communication (signal transmission / reception) between a circuit formed on a wiring board (not shown) arranged above or below 0 and a circuit formed on the wiring board 10 is optically performed. An optical signal from an optical semiconductor device (not shown) on the lower wiring substrate passes through the light receiving element lens 242 of the optical semiconductor device 20 on the wiring substrate 10 along the optical axis, and the light receiving element in the optical semiconductor device 20. Is transmitted to the circuit formed on the wiring board 10 from this light receiving element as an electric signal. On the other hand, a signal from the circuit formed on the wiring board 10 is emitted as an optical signal from the light emitting element of the optical semiconductor device 20, and the optical signal is sent along the optical axis to the optical semiconductor device (not shown) on the wiring board above. ) And is transmitted to the circuit formed on this wiring board.

As shown in FIGS. 3A and 3B, the optical semiconductor device 20 has an optical semiconductor element in a package 24, and the optical semiconductor element is an LED (Light Emitted Diode).
And a light emitting element 211 such as an LD (Laser Diode) and a PD
(Photo Diode) or the like, and its optical axis intersects vertically with these optical semiconductor elements 211 and 212 mounted horizontally on the element mounting portions 221 and 222 arranged horizontally. There is. An internal lead 261 arranged inside the package 24 is integrally connected to the element mounting portion 221 to which the light emitting element 211 is attached. The internal lead 261 is an external lead led out of the package 24. 251, and is integrally connected. The element mounting portion 221, the outer leads 251, and the inner leads 261 are formed by molding the first lead frame. Similarly, the element mounting portion 222 to which the light receiving element 212 is attached is connected to an internal lead 262 integrally arranged in the package 24, and the internal lead 262 is
It is connected integrally with an external lead 252 led out of the package 24. Element mounting portion 222, external lead 252
The inner leads 262 are formed by molding the second lead frame.

The optical axes of the light emitting element 211 and the light receiving element 212 are arranged so that they coincide with each other and face in opposite directions. The bonding wire 23 electrically connects the electrode pad (not shown) of the light emitting element 211 on the element mounting portion 221 of the first lead frame and the internal lead 223 which is not continuously connected to the element mounting portion 221. Then, the element mounting portion 221 and the internal lead 224 are electrically connected. Similarly, the bonding wire 23 electrically connects the electrode pad (not shown) of the light receiving element 212 on the element mounting portion 222 of the second lead frame and the internal lead 225 which is not continuously connected to the element mounting portion 222. Then, the element mounting portion 222 and the internal lead 226 are electrically connected. The package 24 is made of, for example, a molded body of a translucent resin such as an epoxy resin, and has an optical semiconductor element such as a light emitting element 211 and a light receiving element 212.
Element mounting portions 221 and 2 of the first and second lead frames
22 and the inner leads 261 and 262 are covered.

The translucent resin package 24 is a dome-shaped lens 241, 24 integrally molded with the main body.
2 and these protrude from the package 24 main body in mutually opposite directions along the optical axis direction. The dome-shaped lens is formed to concentrate the light emission output of the light emitting element or the light energy of the light receiving element on the optical axis center. At least the tip of the dome-shaped lens portion 241 is the wiring board 10 at least.
Is inserted into the through hole 11. Both the light-receiving element lens and the light-emitting element lens are always formed on these elements. However, its size is arbitrary, and it is sufficient that it covers the element. Also, it may be made a little larger so as to cover the integrated circuit attached to each element. In this example, the integrated circuit is uncoated.
In the optical semiconductor device 20, the external leads 251 and 252 are led out from the package 24 as described above. The external leads 251 and 252 are drawn out horizontally from the side portion of the package 24 and then bent in the protruding direction of the dome-shaped lens portion 241, and the tip portions thereof are bent again horizontally. Then, the external leads 251 and 252 are soldered to the wiring 12 of the wiring board 10. The optical axis of the optical semiconductor device 20 is formed parallel to the protruding direction of the dome-shaped lens portion, and is formed in the direction perpendicular to the surface of the wiring board 10.

This optical semiconductor device 20 is manufactured through the steps of die bonding, wire bonding, packaging, lead plating, lead cutting, lead forming, etc. of the optical semiconductor elements 211 and 212, as in the usual semiconductor device manufacturing method. To be done. 4 and 5 show the internal structure of the package 24. As shown in FIGS. 3A and 3B, the optical semiconductor device includes a light emitting element and a light receiving element, which are arranged vertically with their optical axes aligned. Therefore, FIG. 4 is used to show the plane inside the package in which the light emitting element 211 is arranged, and FIG. 5 is used to show the plane inside the package below the previous figure where the light receiving element 212 is arranged. First, the optical semiconductor device 20
The package 24 includes, for example, a light emitting element 211 including an LED and an integrated circuit (IC) 271 that controls the light emission. The integrated circuit 271 is fixed to the board mounting portion 281 and includes an input terminal and a GND terminal. A signal from an external circuit is input to the integrated circuit 271 from the input terminal as an input signal. The light emitting element 211 is operated at 5V. The light emitting element 211 is fixed to the board mounting portion 221,
It has a 5V terminal.

Each terminal is provided with an external lead 251 and an internal lead 261, which are connected to the board mounting portion 22.
First lead frame (not shown) together with 1, 281
Formed from. On the other hand, the light receiving element 212 including a PD
Has an integrated circuit (IC) 272 for controlling the light reception. The integrated circuit 272 is fixed to the board mounting portion 282 and has an output terminal and a GND terminal. An external optical signal received by the light receiving element is converted into an electric signal, controlled by the integrated circuit 272, and transmitted from an output terminal to an external circuit. The light receiving element 212 is operated at 5V. The light receiving element 212 is fixed to the board mounting portion 222 and has a 5V terminal. Each terminal includes an external lead 252 and an internal lead 262, and these leads are connected to the board mounting portion 22.
Second lead frame (not shown) with 2, 282
Formed from.

FIG. 6 is a cross-sectional view of the board mounting apparatus of this embodiment, which illustrates optical space transmission performed using this board mounting apparatus. This board mounting device is composed of a large number of wiring boards, but in this figure, three wiring boards in the middle are shown, and another wiring board is further stacked above and below the wiring board. Three wiring boards 101, 102, and 103 are used to describe the optical space transmission. Two optical semiconductor devices 201 and 20 are provided on each wiring board.
2, 203 and 204, 205 and 206 are installed. The electronic components constituting the circuit of the wiring board mounted on the wiring board are mounted on the surface of the wiring board on which the optical semiconductor device is mounted. At the time of this mounting, the dome-shaped lens 241 or the dome-shaped lens 242 of each optical semiconductor device is arranged so as to project into the through hole 11 of the wiring boards 101 to 103, and the optical axis of each optical semiconductor device is inside the through hole 11. Are formed so as to penetrate through in parallel. Wiring boards 101-10
3 are arranged in parallel at equal intervals, and each wiring board 10
The two through holes 11 formed in Nos. 1 to 103 overlap each other. Since the optical axis of each optical semiconductor device is formed in the through hole 11, the three wiring boards 101 to 103 include the optical axis of each optical semiconductor device.
The optical axis 1 and the optical axis 2 of the book are formed. The optical signals on the optical axis are transmitted in such a manner that the optical axis 1 is directed from the bottom to the top and the optical axis 2 is directed from the top to the bottom so that bidirectional transmission is possible.

FIG. 7 is a plan view of the wiring board 101.
The arrangement of an optical semiconductor device that communicates signals between wiring boards is described. As shown in the figure, the pair of optical semiconductor devices are mounted close to each other in a region where no other electronic component is mounted. In the figure, it is formed at the corner of the wiring board, but it may be at the center of the side of the wiring board or at the center of the wiring board as long as it is a region where no other electronic component is mounted. According to the board mounting apparatus of the present invention, an optical semiconductor device having a pair of a light emitting element and a light receiving element with their optical axes aligned with each other is mounted so that the lens is arranged in the through hole of the wiring board. Therefore, among the laminated wiring boards, it is not necessary to mount electronic components on both surfaces of the wiring boards in the lamination, and only one-sided wiring can be mounted on one side, so that low cost can be realized. Further, the optical semiconductor device can be accurately arranged on the two sets of optical axes.

8 to 10 show a cross section of the exterior and package of the optical semiconductor device of this embodiment. FIG. 8 is a plan view of the upper part of the package of the optical semiconductor device, and FIG.
8 is a side view seen from the direction B of FIG. 8, and FIG. 9B is a side view of FIG.
10A is a side view seen from the direction, FIG. 10A is a plan view of the lower portion of the package of FIG. 8, and FIG. 10B is a cross-sectional view of a portion taken along the line AA ′ of FIG. This figure shows, for example, an optical semiconductor device 202 attached to the wiring substrate used in FIG. The resin encapsulation package 24 includes a lens 241 that covers the light emitting element 211 supported by the substrate mounting portion 221.
And the light receiving element 21 supported by the board mounting portion 222
2 is provided with a lens 242. Package 2
An external lead 251 on the light emitting element side and an external lead 252 on the light receiving element side are led out from FIG.

Next, a second embodiment will be described with reference to FIG. The figure is a cross-sectional view of an optical semiconductor device. The board mounting apparatus of the present invention is mounted on each wiring board on which a pair of optical semiconductor devices, each of which is composed of a pair of light emitting elements and light receiving elements (hereinafter, referred to as light emitting / light receiving elements) whose optical axes are aligned, is laminated,
It is characterized by matching the optical axes. In order to attach the optical semiconductor device to the wiring board, the optical axis is placed in the through hole of the wiring board. This embodiment is characterized by using a pair of light emitting / receiving elements in the optical semiconductor device. Since the optical semiconductor device having such a structure is attached to the wiring board, the distance between the pair of optical axes can be accurately determined in advance. In the figure, the mounting surface on the wiring board is facing up. A first light emitting / receiving element is arranged on the optical axis 1, and this element is the first light emitting element 21 supported by the board mounting portion 223.
3 and a first light receiving element 214 that is arranged below the light receiving element 3 and is supported by the substrate mounting portion 224. The first light emitting element 213 is electrically connected to the integrated circuit 273 supported by the substrate mounting portion 283, and the first light receiving element 214 is
It is electrically connected to the integrated circuit 274 supported by the substrate mounting portion 284.

A second light emitting / receiving element is arranged on the optical axis 2, and this element is composed of a second light emitting element 215 and a second light receiving element 216 arranged thereon. This element is composed of a second light emitting element 215 supported by the substrate mounting portion 225 and a second light receiving element 216 arranged thereon and supported by the substrate mounting portion 226. The second light emitting element 215 is electrically connected to the integrated circuit 275 supported by the substrate mounting portion 285, and the second light receiving element 216.
Are electrically connected to the integrated circuit 276 supported by the substrate mounting portion 286. Since the positions of the light emitting element and the light receiving element of the second light emitting / light receiving element are upside down with respect to the first light emitting / light receiving element, the light emitting direction and the light receiving direction of both light emitting / light receiving elements are opposite. ing. In the present invention, in the optical semiconductor device using the pair of light emitting / receiving elements as in the second embodiment, it is not necessary to reverse the light emitting direction or the light receiving direction of the first and second light emitting / receiving elements. .
The light emitting direction or the light receiving direction can be the same. Such an optical semiconductor device can be applied to a board mounting device that connects circuits of a wiring board by a plurality of communication means.

Next, with reference to FIGS. 12 to 14, one cross section of the package and the package of the optical semiconductor device of this embodiment is shown. 12 is a plan view of the upper part of the package of the optical semiconductor device, FIG. 13 (a) is a side view seen from the direction B in FIG. 12, and FIG. 13 (b) is a side view seen from the direction C in FIG. 14
FIG. 14A is a plan view of the lower portion of the package of FIG.
12B is a sectional view of a portion taken along the line AA ′ in FIG. These figures show the exterior of the optical semiconductor device of FIG. The resin encapsulation package 24 includes the board mounting portion 22.
The lens 243 which covers the light emitting element 213 supported by the lens 3, the lens 244 which covers the light receiving element 214 which is supported by the substrate mounting portion 224, and the lens 24 which covers the light emitting element 215 which is supported by the substrate mounting portion 225.
5, the light receiving element 21 supported by the board mounting portion 226
6 is provided with a lens 246. Package 2
External leads 253 and 255 on the light emitting element side and external leads 254 and 256 on the light receiving element side are led out from FIG. 4, respectively.

Next, a third embodiment will be described with reference to FIG. The figure is a cross-sectional view of the substrate mounting apparatus. The board mounting apparatus of this embodiment is composed of three laminated wiring boards. Conventional optical semiconductor devices are mounted on the upper and lower wiring boards 104 and 105. Upper wiring board 10
No. 4 does not need to send a signal to it or receive it from above, and the wiring board 105 below does not need to send a signal below it or receive it from below. Therefore, the conventional optical semiconductor device mounted on the conventional wiring substrate having no through hole can be used as the upper and lower wiring substrates. The light receiving element 600 and the light emitting element 603 are attached to the lower surface of the upper wiring board 104. A light emitting element 601 and a light receiving element 602 are attached to the upper surface of the lower wiring board 105. The wiring board 106 according to the present invention is arranged between the upper and lower wiring boards 104 and 105.
An optical semiconductor device according to the present invention having a pair of light emitting / receiving elements is attached.

A pair of through holes 11 are formed in the wiring board 106, and the lenses of the optical semiconductor devices 207 and 208 are inserted into the through holes 11 from below. A light emitting lens is inserted on the left side, and a light receiving lens is inserted on the right side.
Although not shown in the drawing, the wiring boards 104 and 106 are provided with electronic components constituting the circuits on the bottom surface of the wiring board 1 and the wiring board 1
In 05, electronic components that form the circuit are formed on the upper surface of the substrate. In this embodiment, the distance between the optical axes can be made exactly constant. The optical semiconductor device used in this embodiment may be one having two lenses each having a pair of light emitting / receiving elements used in the second embodiment formed on the upper surface and the lower surface.

Next, a fourth embodiment will be described with reference to FIG. This embodiment is characterized in that no lens is formed on the light receiving surface of the light receiving element. The figure is a cross-sectional view of an optical semiconductor device. In this embodiment, like the other embodiments, the optical semiconductor device is composed of a pair of light emitting / receiving elements whose optical axes are aligned. The light emitting element 217 and the light receiving element 218
Are arranged above and below so that their optical axes coincide with each other, and these elements are formed by a lead frame.
It is equipped with leads 257 and 258 which are supported by 28 and which input and output input signals and output signals. In order to attach the optical semiconductor device to the wiring board, the optical axis is placed in the through hole of the wiring board. The resin mold package 24 covers the pair of light emitting / receiving elements, the element mounting portion, and part of the leads. A part of the resin mold package 24 serves as a lens 247 and is arranged above the light emitting surface of the light emitting element 217. No lens is applied to the light-receiving surface.
Since light reception does not require directivity as much as light emission, it is possible to provide a lens on the light receiving surface that does not require high accuracy. Since the optical semiconductor device having such a structure is attached to the wiring substrate, the substrate mounting device has a reduced number of lenses, which enables downsizing.

Next, a fifth embodiment will be described with reference to FIG. This embodiment is characterized in that lenses are not formed on the light emitting surface of the light emitting element and the light receiving surface of the light receiving element. The figure is a cross-sectional view of an optical semiconductor device. In this embodiment, like the other embodiments, the optical semiconductor device is composed of a pair of light emitting / receiving elements whose optical axes are aligned. This light emitting element 2
19 and the light receiving element 220 are vertically arranged so that their optical axes coincide with each other, and these elements are supported by element mounting portions 229 and 230 formed from a lead frame, and leads 259 and 260 for inputting and outputting an input signal and an output signal. Is equipped with. In order to attach the optical semiconductor device to the wiring board, the optical axis is placed in the through hole of the wiring board. The resin mold package 24 covers the pair of light emitting / receiving elements, the element mounting portion, and part of the leads. If the resin mold package 24 does not require a high degree of directivity in the optical semiconductor device, it is not necessary to dispose the lens in this way. Since the optical semiconductor device having such a structure is attached to the wiring board, the board mounting apparatus has no lens and can be made thin and small.

[0029]

As described above, according to the present invention, an optical semiconductor device can be mounted on a plurality of wiring boards with high accuracy so that the optical axes thereof coincide with each other, and communication is performed between three or more wiring boards. Even in this case, the wiring board can be mounted on one side by single-sided wiring, so that a low-cost board mounting device can be obtained.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an optical device mounted on a wiring board according to a first embodiment of the present invention.

FIG. 2 is a plan view of the optical semiconductor device of FIG. 1 and a side view of the optical semiconductor device as seen from the direction A.

3 is a cross-sectional view of a portion along line BB ′ in FIG. 2 and C-
Sectional drawing of the part which follows the C'line.

FIG. 4 is a plan view of a light emitting element portion inside the package of FIG.

5 is a plan view of a light receiving element portion inside the package of FIG.

FIG. 6 is a sectional view of a wiring board to which an optical semiconductor device is attached.

FIG. 7 is a plan view of a wiring board to which an optical semiconductor device is attached.

FIG. 8 is a plan view showing the upper portion of the optical semiconductor device of the first embodiment.

9 is a side view of the optical semiconductor device viewed from the B direction and the C direction in FIG.

10 is a plan view and a cross-sectional view showing the bottom of the optical semiconductor device of FIG.

FIG. 11 is a sectional view of an optical semiconductor device according to a second embodiment.

FIG. 12 is a plan view showing an upper portion of an optical semiconductor device according to a second embodiment.

13 is a side view of the optical semiconductor device as seen from the B direction and the C direction in FIG.

14 is a plan view showing the bottom of the optical semiconductor device of FIG. 12 and a cross-sectional view of a portion taken along the line AA ′ of FIG.

FIG. 15 is a sectional view of a board mounting apparatus according to a third embodiment.

FIG. 16 is a sectional view of an optical semiconductor device according to a fourth embodiment.

FIG. 17 is a sectional view of an optical semiconductor device according to a fifth embodiment.

FIG. 18 is a cross-sectional view of an optical semiconductor device mounted on a conventional wiring board.

19 is a plan view of the optical semiconductor device of FIG. 18, a side view seen from the direction D, and a cross-sectional view of a portion along the line CC ′.

FIG. 20 is a cross-sectional view of a conventional board mounting device.

FIG. 21 is a sectional view of a conventional board mounting device.

[Explanation of symbols]

10, 101, 102, 103, 104, 105, 10
6 Wiring Board 11 Through Hole 12 Wiring 20, 201, 202, 203, 204, 205, 20
6, 207, 208 Optical semiconductor device 23 Bonding wire 24 Resin sealing body 25, 251, 252, 253, 254, 255, 25
6, 257, 258, 259, 260 External leads 211, 213, 215, 217, 219 Light emitting element 212, 214, 216, 218, 220 Light receiving element 221, 222, 223, 224, 225, 226, 2
81, 282, 283, 284, 285, 286
Substrate mounting part 241, 242, 243, 244, 245, 246, 2
47 lenses 261, 262, 263, 264, 265, 266, 2
67, 268, 269, 270 Internal lead 271, 272, 273, 274, 275, 276
Integrated circuit 600, 602 Receiver 601, 603 Transmitter

Claims (6)

[Claims] 1. A light emitting element having a light emitting portion for emitting light to the outside, a light receiving element having a light receiving portion for receiving light from the outside, a first lead for transmitting an electric signal of an external circuit to the light emitting element, A second lead for transmitting an optical signal from the light receiving portion to an external circuit as an electric signal; a part including the light emitting element, the light receiving element, one end of the first lead and one end of the second lead; A resin mold package that is transparent at least in a region that covers the light emitting unit and the light receiving unit, and the optical axis of the light emitting unit and the optical axis of the light receiving unit are coincident with each other, and An optical semiconductor device, wherein the light emitting surface of the light receiving portion and the light receiving surface of the light receiving portion face in mutually opposite directions. 2. A lens is attached on either one of the light emitting surface of the light emitting portion and the light receiving surface of the light receiving portion or on the light receiving surface or the light emitting surface such that the optical axis is in the center thereof. The optical semiconductor device according to claim 1, wherein the lens is formed integrally with the resin mold package. 3. The light emitting element and the light receiving element are each 2
Each of them has a first optical axis composed of a first light emitting element and a first light receiving element, a second light emitting element and a second light receiving element in the resin mold package. The optical semiconductor device according to claim 1 or 2, further comprising: 4. The optical semiconductor device according to claim 3, wherein the light emitting direction of the first light emitting element is opposite to the light emitting direction of the second light emitting element. 5. A plurality of wiring boards having through holes, arranged and stacked at intervals, and an optical semiconductor mounted on the wiring boards and arranged so that an optical axis passes through the inside of the through holes. The optical semiconductor device includes a light emitting element having a light emitting portion for emitting light to the outside, a light receiving element having a light receiving portion for receiving light from the outside, and an optical signal for transmitting an electric signal of an external circuit to the light emitting element. One lead, a second lead for transmitting an optical signal from the light receiving section to an external circuit as an electric signal, the light emitting element, the light receiving element, a part including one end of the first lead, and the second lead A part including the one end of the lead is covered, and at least a region covering the light emitting part and the light receiving part is provided with a transparent resin mold package, and the optical axis of the light emitting part and the optical axis of the light receiving part are Matches and the emission Substrate mounting apparatus characterized by the facing opposite directions with the light emitting surface and the light-receiving surface of the light receiving portion of the. 6. The optical semiconductor device according to claim 1, wherein an optical axis is located at the center of the light emitting surface of the light emitting portion and the light receiving surface of the light receiving portion or the light receiving surface and the light emitting surface. The board mounting device according to claim 5, wherein a lens is attached and the lens is integrally molded with the resin mold package.