JPS5832515B2 - handoutaihikariketsugousoshi - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a semiconductor coupling device that obtains optical coupling by combining a light emitting element die and a light receiving element die, and in particular improves the optical coupling efficiency and simplifies the assembly process. It is something.

A cross section of an example of a conventional semiconductor optical coupling device is shown in FIGS. 1 and 2.

Of these, FIG. 2 is a cross-sectional view taken from a different direction from FIG. 1. Of these two figures, in FIG. Alternatively, a visible light emitting diode using GaP material is used.

Moreover, as the light receiving element die 2, Cds, Cd5e
, Si photodiode or transistor, but here we will use GaAs infrared light emitting diode and S i photodiode.
The case of an i-phototransistor will be explained.

Now, the light emitting diode 1 is die-bonded to the lead 4, and the other electrode 9 of the light emitting diode 1 and the lead 3 are connected to the thin metal wire 1.
0 to wire bond to obtain electrical connection.

Similarly, for the light receiving element, the phototransistor 2 is die-bonded to the lead 7, and the emitter electrode 11 and the lead 6 are die-bonded.
, and the base electrode 12 and the lead 8 are each connected to a thin metal wire 1.
3 and 14 to obtain electrical connection by wire bonding.

Next, a pair of lead frames 101 and 102 were fixed as shown in Fig. 2, a transparent material 15 was filled between the light emitting diode 1 and the phototransistor 2, and the whole was molded with an opaque material 16 to block external light. It is something.

For the transparent material 15 and the opaque material 16, inexpensive plastics such as epoxy resin and silicone resin are often used.

When such a conventional semiconductor optical coupling device operates, an input signal is applied to the leads 3 and 4, causing the light emitting diode 1 to emit light, and the emitted light is transmitted through the transparent material 15.
The light passes through the phototransistor 2, generates a photocurrent, and is taken out as an output signal.

However, in this way, a pair of lead frames 101.1
When fixing the light emitting diode 1 and the phototransistor 2, the distance between the light emitting diode 1 and the phototransistor 2 must be sufficiently widened so that the thin metal wires 10°13.14 do not come into contact with each other.

Therefore, the optical coupling efficiency was poor.

Moreover, the optical coupling efficiency varied due to misalignment of the dies 1 and 2 to be die-bonded and bending of the lead frames 101 and 102.

In addition, two types of lead frames 1 after wire bonding are shown.
01 and 102 were difficult to handle until they were sealed with the transparent material 15, and the work required to be skilled and careful when injecting the resin of the transparent material 15, resulting in poor workability and speed. It was making the buildup worse.

The present invention has been made in view of the above-mentioned drawbacks, and an object thereof is to provide a semiconductor optical coupling device having a structure that improves optical coupling efficiency and simplifies work.

Next, embodiments of the semiconductor optical coupling device of the present invention will be described with reference to the drawings. FIGS. 3a to 3f each show the manufacturing process of the semiconductor optical coupling device of the present invention. First, in FIG. 3a, an electrode plate 17 is formed by plating one side of an insulating plate made of ceramic, polyimide, Bakelite, or a printed circuit board with copper, silver, gold, or the like.

A conductive epoxy resin 18 is applied to the conductive surface of the electrode plate 17, and then the conductive epoxy resin 18 is applied by aligning the light emitting diode 1 (FIG. 3b) with the window 19 of the electrode plate 17 through which light passes. Die-bond to the exposed side and heat cure to fix.

Note that the electrode 9 on the side from which the light of the light emitting diode 1 is emitted is provided around the window 19 so that light can be emitted effectively, and 21 is the electrode of the light emitting diode.

Next, a transparent material 15 (FIG. 3C) is placed on the window 19 through which light passes.
inject.

Since this transparent material 15 needs to be insulative and have an adhesive effect, epoxy resin is suitable.

After injecting the transparent material 15, the phototransistor 2 is placed on the transparent material 15 as shown in FIG. harden and fix.

This phototransistor 2 has an emitter electrode 11, as shown in FIG. 4a (a plan view of the semiconductor optical coupling device of the present invention) and FIG. Base electrode 1
The bonding workability is better when each of the bonding portions 23 and 24 of No. 2 is located at a corner.

Further, the surface of the parts other than the bonding parts 23 and 24 is insulated with an insulating material 29 such as phosphor glass, and the electrically resistant ball becomes larger if the parts are bonded to the insulating surface of the electrode plate 17.

Next, as shown in FIG. 3e, the leads 20 of the lead frame 103 are die-bonded using a conductive epoxy resin 18.

Then, the back electrode 21 of the light emitting diode 1 and the lead 30
(See FIG. 3f; however, FIG. 3f is a plan view of FIG. 3e.) The conductive surface of the electrode plate 17 and the lead 31
, the bonding portions 23, 24 of the base electrode 12 and the leads 33, 34 are wire-bonded using the thin metal wires 22 to obtain electrical connection.

Finally, the entire structure is sealed with an opaque material 16.

In the figure, 20 is a lead, 25 is a collector electrode of the phototransistor, 32 is a lead, 26 is an emitter region,
27 is a base area, and 28 is a collector area.

In the above embodiment, the case where a phototransistor was used as the light receiving element was explained, but it is also possible to use other semiconductor elements such as a photodiode, and a conductive epoxy resin can be used as the conductive adhesive. Although described above, a solder material such as Au-8i may also be used.

Further, in the above description, a case has been described in which only one side of the electrode plate 17 is subjected to conductive treatment, but the other side may also be subjected to conductive treatment to be used as one electrode of a phototransistor or the like.

As described above, according to the semiconductor optical coupling device of the present invention,
The following effects can be achieved.

(1) Since the distance between the light-emitting element and the light-receiving element is approximately the same as the thickness of the electrode plate, they can be positioned very close together, and the light from the light-emitting element reaches the light-receiving element without leaking to the outside, allowing optical coupling. Improved efficiency.

(2) The thickness of the electrode plate is uniform, and the structure is such that it is not affected by misalignment of the die to be bonded, so there is little variation in optical coupling efficiency.

(3) It becomes easier to inject a transparent substance between the light emitting element and the light receiving element.

(4) The wire bonding of the light-emitting element and the light-receiving element, which was conventionally done separately, can be done at the same time, so the assembly process can be simplified.

(5) The lead frame does not require an expensive mold for bending, and it is inexpensive because two types of lead frames are replaced by one type.

(6) Since the work is simplified overall, workability is improved and yield is improved.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a conventional semiconductor optical coupling device, FIG. 2 is a cross-sectional view of the same semiconductor optical coupling device taken in a direction different from that in FIG. 1, and FIGS. FIG. 3f is a plan view of FIG. 3e, and FIG.
FIG. 4A is a plan view of an embodiment of the semiconductor optical coupling device of the present invention, and FIG. 4 is a sectional view of FIG. 4A. DESCRIPTION OF SYMBOLS 1... Light emitting diode die, 2... Phototransistor die, 9... Light emitting diode electrode, 17... Electrode plate, 18...・Conductive epoxy resin, 20.30-34... Lead, 21... Back electrode of light emitting diode, 22
...Metal thin wire, 23... Bonding part of emitter electrode, 24... Bonding part of base electrode, 25... Collector electrode of phototransistor, 29. ...Insulating layer. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Claims] 1. An electrode plate that has a window through which light passes and has conductive treatment applied to one or both sides of the insulating plate, and one side of the electrode plate is coated with a conductive substance and the electrode on one side of the light emitting element die is adhered to it. a light-emitting element, an insulating transparent material injected into the window with the light-emitting element adhered, and a portion other than the first electrode adhered to the other surface of the electrode plate via an insulating substance. A light-receiving element, a lead frame die-bonded to the second electrode of the light-receiving element via a conductive resin that does not require bending, and each electrode of the light-emitting element and the light-receiving element being wire-bonded, and the whole is sealed. A semiconductor optical coupling device comprising an opaque substance.