JPH04369873A - Photoelectric ic module - Google Patents

Abstract

PURPOSE:To provide an IC package where signal light is inputted or outputted through both its surfaces and an photoelectric IC module structure provided with the IC packages which can be mounted high in density. CONSTITUTION:A first wiring metal 17 provided with a window 19 for signal light is deposited on a transparent package substrate 16, and a mesa-shaped photoelectric IC provided with a light emitting element of a photodetective element is mounted thereon. An electrode 22 is deposited on the top of a mesa 21, and the electrode 22 is bonded to the first wiring metal 17. A part of the top of the mesa 21 where the electrode 22 is not deposited is aligned with the window 19 of the first wiring metal 17, output light 26 emitted from the mesa 21 is outputted from the package 16 through the window 19. Input light 25 is made to impinge on the rear side of the IC substrate 20.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mounting technique for a photoelectronic IC including a light receiving element and a light emitting element which input or output signal light from an approximately perpendicular direction to an IC substrate.

0002

2. Description of the Related Art A photoelectronic IC including a light-receiving element and a light-emitting element that inputs or outputs signal light from an approximately perpendicular direction to an IC substrate is disclosed in Japanese Patent Application No. 60-18404, for example.
There is an image storage device disclosed in Publication No. 7. As shown in FIG. 4, this device has optical bistable elements 1 arranged in a two-dimensional array on an IC board 2, and stores two-dimensional optical information inputted by input light 3 and outputs it as output light 4. It functions as an optical input/output storage device for output. The optical bistable element 1 is
A light-emitting element and a phototransistor (light-receiving element) that can receive light emitted from the light-emitting element are connected in series.
1) Even if a bias voltage (holding voltage) that allows the phototransistor to take an on state is applied, no current flows through the phototransistor and the light emitting element does not emit light (off state). (2) The applied voltage remains at the holding voltage. , when input light enters the phototransistor, a current flows and the light emitting element emits light (on state), (3)
Even if the input light is stopped while the applied voltage remains at the holding voltage, the phototransistor receives the light emitted from the light emitting element, so the on state is maintained. ), it returns to the off state.

In this image storage device, the input light 3 is I
Since the light enters from the back surface of the C board 2 and the output light 4 is emitted upward from the IC board 2, an IC package that can input and output light from both sides is required. However, conventional packages do not support, for example, rewritable read-only memories (EPROMs) or charge-coupled devices (EPROMs) that are erased using ultraviolet light.
Although there are CCD packages that allow light to be input from the top surface, there are no packages that allow signal light to be input and output from both sides. That is, it is impossible to modularize the image storage device using conventional packages.

0004

[Problem to be solved by the invention] Patent application 1840-1986
The image storage device shown in Publication No. 47 is a conventional IC.
Although it is impossible to modularize using a package, more generally, it is possible to modularize an optoelectronic IC that includes a light receiving element and a light emitting element that input or output signal light from approximately perpendicular to the IC substrate. In this case, it is desirable to use an IC package that can input and output signal light from both sides. This is because when inputting and outputting both input and output light from the top surface, optical components such as a half mirror or polarizing beam splitter are required to separate the input and output lights, which increases the number of steps for optical alignment. Moreover, it becomes difficult to downsize the entire device.

SUMMARY OF THE INVENTION Accordingly, a first object of the present invention is to provide an IC package capable of inputting and outputting signal light from both sides, and a structure of an optoelectronic IC module using the IC package. A second object of the present invention is to provide a novel structure in which optoelectronic ICs that input and output signal light from both sides are mounted in high density.

[0006]

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present invention provides a photoelectronic IC including a light receiving element and a light emitting element that input or output signal light from a direction approximately perpendicular to an IC substrate, and a through hole. a pedestal having a pedestal and a package including a lead electrically insulated from the pedestal; The structure is such that a photoelectronic IC is mounted on the package.

[0007] A photoelectronic IC including a light receiving element and a light emitting element that input or output signal light from a direction approximately perpendicular to the IC substrate, and a wiring metal having a window for the signal light is attached to the signal light. The photoelectronic IC is provided with a transparent package substrate, and the optoelectronic IC is mounted on the package by aligning the light receiving element or the light emitting element with the window.

Alternatively, at least two optoelectronic ICs including a light receiving element and a light emitting element that input or output signal light in a direction approximately perpendicular to the IC substrate are stacked,
The IC substrate is transparent to the signal light, and the light emitting element or the light receiving element of the optoelectronic IC has a mesa shape, and electrodes formed at the top of the mesa are stacked adjacent to each other. A photoelectronic IC module is constructed by bonding the photoelectronic IC to the back surface of the photoelectronic IC.

[0009]

[Operation] In the first configuration of the optoelectronic IC module of the present invention, a through hole is formed in the base of the IC package, and the optoelectronic IC is mounted on the through hole. At this time, the area of the through hole is made slightly smaller than the chip size of the optoelectronic IC, and a guide for fitting the optoelectronic IC is provided around the through hole. For example, a non-penetrating guide hole of the same size as the photoelectronic IC is made around the through hole, and the photoelectronic IC is fitted into the guide hole. At this time, if the light receiving element or light emitting element in the optoelectronic IC is positioned above the through hole, it is possible to input and output signal light from the back side of the package. Furthermore, if the wire bonding pad is positioned above the guide hole which is off from the through hole, wire bonding can be performed in the same way as with a normal IC.

[0010] In the second configuration of the present invention, for example, glass,
A transparent package substrate made of plastic or the like is coated with wiring metal to form a package. A window for signal light is opened in this metal wiring, and a photoelectronic IC is mounted by aligning the window with a light receiving element or a light emitting element. This allows signal light to be input and output from the back side of the package as well. The optoelectronic IC may be bonded with the surface on which the light receiving element and the light emitting element are formed facing upward, and the bonding pad of the optoelectronic IC and the wiring metal of the package may be connected by wire bonding, but if the light emitting element or the light receiving element is in a mesa shape, In the case where the mesa has this surface facing down, the electrode formed on the top of the mesa may be directly bonded to the wiring metal of the package. The latter structure has advantages such as eliminating the need for electrical wiring within the optoelectronic IC and efficiently dissipating heat from the element.

A third configuration of the present invention is to stack two or more optoelectronic ICs and mount them in the same package. At this time, a semiconductor substrate that is transparent to signal light is used as the IC substrate. A light emitting element or a light receiving element in a photoelectronic IC is formed into a mesa shape, and an electrode formed at the top of the mesa is bonded to the back surface of the photoelectronic IC stacked adjacently. Here, if the IC board has a structure in which a semi-insulating semiconductor layer is sandwiched between two conductive semiconductor layers, the conductive semiconductor layer on the back side of the IC board functions as wiring for the optoelectronic IC below, and the IC board It is electrically insulated from elements formed on the surface by a semi-insulating semiconductor layer. Furthermore, since the IC substrate is transparent to signal light, the signal light can be transmitted from the light emitting elements in the upper and lower optoelectronic ICs to the light receiving elements.

0012

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a sectional perspective view of a main part of an optoelectronic IC module according to an embodiment of the present invention. A package is constituted by a pedestal 5 made of metal such as Kovar, an insulating frame 6 made of ceramic or the like, and metal leads 7. The pedestal 5 has a through hole 8 on which a photoelectronic IC 9 is mounted. This optoelectronic IC 9 includes a light receiving element and a light emitting element that input or output signal light from approximately perpendicular to the IC substrate.
I, such as the image storage device shown in Publication No. 4047.
It is C. The size of the through hole 8 is smaller than the chip size of the optoelectronic IC 9, and the optoelectronic IC 9 is fitted into a non-penetrating guide hole 10, which is provided around the through hole 8 and has the same size as the optoelectronic IC 9. At this time, the active region 11 in which the light receiving element or the light emitting element in the photoelectronic IC 9 is integrated.
is positioned above the through hole 8. Further, the pad 12 for wire bonding is positioned above the guide hole 10 which is removed from the through hole 8, and wire bonding is performed between the pad 12 and the lead 7 using the wire 13. When the optoelectronic IC 9 is the image storage device described above, the input light 14 enters from the back surface of the package, and the output light 15 is emitted upward from the optoelectronic IC 9.

FIG. 2(A) is a sectional view of a photoelectronic IC module according to a second embodiment of the present invention, and FIG. 2(B) is a plan view of a package which is a component thereof. The package includes a transparent package substrate 1 made of glass, plastic, etc.
The first wiring metal 17 has a window 1 for signal light, and the first wiring metal 17 has a window 1 for signal light.
9 is provided. On the other hand, the optoelectronic IC mounted in this package includes a light receiving element and a light emitting element that input or output signal light from a direction approximately perpendicular to the IC substrate 20, and the light emitting element or the light receiving element has a mesa shape. There is. An electrode 22 is deposited on the top of the mesa 21, and the first wiring metal 17 is bonded to the electrode 22. In order to bond the electrode 22 and the first wiring metal 17, for example, a bump made of In or the like is formed on the surface of the electrode 22, and this and the first wiring metal 17 made of Au or the like are thermally fused. During this bonding, the portion of the top of the mesa 21 on which the electrode 22 is not deposited is aligned with the window 19 of the first wiring metal 17, and the signal light is transmitted through the window 19.
It is possible to input and output to and from the mesa 21 through this. Further, the back electrode 23 of the IC board 20 and the second wiring metal 18
A wire 24 connects between them. Photoelectronic IC
When is the image storage device shown in Japanese Patent Application No. 60-184047, the input light 25 enters from the back surface of the IC board 20, and the output light 26 is emitted from the mesa 21 through the package board 16. . According to this structure, electrical wiring within the optoelectronic IC becomes unnecessary, and heat generated from the light emitting element is efficiently radiated to the package substrate.

FIG. 3 shows a photoelectronic IC according to a third embodiment of the present invention.
FIG. 3 is a cross-sectional view of the module. This is two or more photoelectrons I
C is stacked and mounted in the same package,
FIG. 3 shows an example for two optoelectronic ICs. Figure 3
Although no package is shown in , if the package shown in the first or second embodiment of the present invention is used, it is easy to mount this structure in a package. The first and second optoelectronic ICs 27, 28 have the same structure, and three or more optoelectronic ICs can also be stacked in a similar structure. First and second optoelectronic IC2
The IC boards 29 of 7 and 28 are transparent to the signal light,
It consists of three layers: a first conductive semiconductor layer 30, a semi-insulating semiconductor layer 31, and a second conductive semiconductor layer 32. In order to make the IC substrate 29 transparent to signal light, a light receiving element and a light emitting element made of, for example, an InGaAsP/InP system may be formed on an InP substrate. Further, the light emitting element or the light receiving element in the photoelectronic IC has a mesa shape, and the electrode 34 formed at the top of the mesa 33 is bonded to the back surface of the IC substrate 29 of the photoelectronic IC stacked adjacently. In order to bond the electrode 34 and the IC substrate 29, for example, a bump made of In or the like is formed on the surface of the electrode 34, and the IC substrate 29 made of InP or the like is thermally fused to the bump.

The second conductive semiconductor layer 32, which corresponds to the ground wiring of the first and second optoelectronic ICs 27, 28, is connected to the leads of the package via first and second pads 35, 36. Further, the first conductive semiconductor layer 30 of the second optoelectronic IC 28 functions as a power supply wiring for the first optoelectronic IC 27 and is connected to a lead of the package via a third pad 37. Here, a semi-insulating layer is formed between the first conductive semiconductor layer 30 and the second conductive semiconductor layer 32 so that the power supply wiring of the first optoelectronic IC 27 and the ground wiring of the second optoelectronic IC 28 are insulated. A semiconductor layer 31 is provided. The power supply wiring of the second optoelectronic IC 28 may be formed on the IC, but if the mounting structure shown in the second embodiment of the present invention is used, the wiring on the package substrate can be used as the power supply wiring. Can be done. Since the IC board 29 is transparent to the signal light, the first output light 38 from the light emitting element in the first optoelectronic IC 27 is transmitted to the IC board 29 of the second optoelectronic IC 27.
can be input to the light receiving element in the second photoelectronic IC 28 through the photoelectronic IC 28. Input light 3 to the light receiving element in the first photoelectronic IC 27
9 is input through the IC board 29 of the first optoelectronic IC 27, and the second output light 40 from the light emitting element in the second optoelectronic IC 28 is output upward from the second optoelectronic IC 28.

[0016]

According to the first or second configuration of the present invention, an IC package capable of inputting and outputting signal light from both upper and lower surfaces and a photoelectronic IC module using the same can be realized. This allows a half mirror or polarized beam to be used to separate input light and output light when modularizing a photoelectronic IC that includes a light receiving element and a light emitting element that input or output signal light from a direction approximately perpendicular to the IC substrate. Optical components such as a splitter are not required, the number of steps for optical alignment can be reduced, and the entire device can be downsized. Furthermore, according to the third configuration of the present invention, high-density packaging is realized in which two or more optoelectronic ICs that input and output signal light from both sides are stacked. Furthermore, according to the second or third configuration of the present invention, power supply wiring within the optoelectronic IC becomes unnecessary, and high density integration of the optoelectronic IC becomes easy.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional perspective view of a main part of an optoelectronic IC module according to an embodiment of the present invention.

FIG. 2 is a sectional view and a plan view of an optoelectronic IC module according to a second embodiment of the present invention.

FIG. 3 is a sectional view of an optoelectronic IC module according to a third embodiment of the present invention.

FIG. 4 is a perspective view of a conventional optoelectronic IC.

[Explanation of symbols]

5 Pedestal 7 Lead 8 Through hole 9 Photoelectronic IC 10 Guide hole 10 16 Package board 17 First wiring metal 19 Window 20 IC board 21 Mesa 22 Electrode 27 First optoelectronic IC 28 Second optoelectronic IC 29 IC board 30 First conductive semiconductor layer 31 Semi-insulating semiconductor layer 32 Second conductive semiconductor layer 33 Mesa 34 Electrode

Claims (6)

[Claims] 1. A photoelectronic IC including a light-receiving element and a light-emitting element that input or output signal light from a direction substantially perpendicular to an IC substrate, a pedestal having a through hole, and a lead electrically insulated from the pedestal. a package, and the optoelectronic IC is mounted on the package so that all or part of the peripheral part of the IC substrate is adhered to all or part of the peripheral part of the through hole. IC module. 2. The optoelectronic IC module according to claim 1, wherein the area of the through hole is smaller than the area of the optoelectronic IC, and a guide for fitting the optoelectronic IC is provided around the through hole. 3. A photoelectronic IC including a light-receiving element and a light-emitting element that input or output signal light in a direction approximately perpendicular to an IC substrate, and a wiring metal having a window for the signal light attached to the signal light. 1. A photoelectronic IC module, comprising: a transparent package substrate; and the photoelectronic IC is mounted on the package by aligning the light receiving element or the light emitting element with the window. 4. The photoelectronic device according to claim 3, wherein the light-emitting element or the light-receiving element has a mesa shape, and the electrode formed on the top of the mesa is bonded to the wiring metal of the package substrate. IC module. 5. At least two photoelectronic ICs each including a light receiving element and a light emitting element that input or output signal light in a direction approximately perpendicular to the IC substrate are stacked,
The C substrate is transparent to the signal light, and the photoelectron I
A photoelectronic IC characterized in that the light emitting element or the light receiving element of C has a mesa shape, and an electrode formed on the top of the mesa is adhered to the back surface of the photoelectronic ICs stacked adjacently. module. 6. The optoelectronic IC module according to claim 5, wherein the IC substrate has a structure in which a semi-insulating semiconductor layer is sandwiched between two conductive semiconductor layers.