JPS6046555B2 - Photocoupler - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a photocoupler having a light emitting part and a light receiving part in the same resin case.
This provides a structure that can easily improve the accuracy of electrical conversion functions (prevent malfunctions).

Conventionally, photocouplers have been constructed as shown in FIG.

That is, the light emitting part semiconductor chip 2a and the light receiving part semiconductor chip 2b are die-bonded onto the lead frame 1a, and then the lead frames lb, lc and the semiconductor chip 2 are bonded.
Connection wires 3a and 3b are connected to the surfaces of a and 2b by wire bonding, respectively, and these are inserted into a hollow, opaque resin case 4 that has a partition wall 5 inside, and then a transparent sealing resin 6 is injected. It was made by hardening. However, in such a configuration, as a result of the operation of the photocoupler, the light from the light emitting part semiconductor chip 2a leaks not only in the a direction but also in the d direction, which reduces the amount of light, and also causes light to leak to the light receiving part semiconductor chip 2b. In addition to the light in the direction only, unnecessary light in the c direction is incident, which can cause malfunctions, so the purity of the photocoupler's electrical-optical-electrical conversion is low.
It was easy for malfunctions to occur.

The present invention is intended to eliminate such conventional drawbacks, and one embodiment thereof will be described below with reference to FIG. 2.

In FIG. 2, the same components as those in the conventional configuration shown in FIG. 2a, 2b and lead frames lb, lc are connected with connection wires 3a, 3b,
After inserting these into the resin case 4, a transparent protective resin layer 7 is provided on the lead frame 1a including at least the semiconductor chips 2a and 2b by coating, and an opaque resin layer 7 is coated with metal foils Ba and 8b on both sides. A plate 9 is press-fitted into the protective resin layer 7 between the semiconductor chips 2a and 2b, and then the light transmission direction is aligned with the semiconductor chips 2a and 2b, respectively.
Optical fibers 10a, 1 are placed perpendicularly to the upper surface of 2b.
0b is similarly press-fitted into the protective resin layer 7, and the optical fibers 10a and 10b are connected to the metal foils 8a and 8b with transparent adhesives 11a and 11b, and then the resin case 4
An opaque sealing resin 12 is injected and cured.
With the above configuration, the light from the light emitting part semiconductor chip 2a becomes only the light in the e direction passing through the optical fiber 10a, eliminating light leakage, and the light entering the light receiving part semiconductor chip 2b passes through the optical fiber 10b. Since only light passes through the f-direction, there is no need to generate light that can cause malfunctions, or receive light in the g-direction, which greatly improves accuracy. It is something. Further, a resin plate 9 having metal foils 8a and 8b on both sides is provided between the light emitting part semiconductor chip 2a and the light receiving part semiconductor chip 2b in contact with the lead frame 1a.
The light-emitting semiconductor chip 2a and the light-receiving semiconductor chip 2b are completely separated, so that malfunctions are prevented by direct light from the light-emitting semiconductor chip 2a to the light-receiving semiconductor chip 2b.

Then, the metal foils 8a and 8b are connected to the optical fibers 10a and 10.
This allows light to pass through efficiently. In addition, in the above embodiment, the resin case 4
Although the sealing resin 12 is filled inside, since both of them are opaque, one can also serve as the other.

As described above, the present invention provides a resin plate having metal foil on both sides between the light-emitting semiconductor chip and the light-receiving semiconductor chip arranged in the same resin case, and is in contact with the metal foil so that the direction of light transmission is adjusted. With a simple configuration in which optical fibers are provided approximately perpendicular to the surface of each of the semiconductor chips, the accuracy of the photocoupler's electricity-to-light-to-electricity conversion function is improved, and reliable operation without malfunction is performed. be.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a conventional example, and FIG. 2 is a sectional view of an embodiment of the present invention. 1a, 1b, 1c...Lead frame, 2...
... Light emitting part semiconductor chip, 2b ... Light receiving part semiconductor chip, 4 ... Resin case, 7 ... Protective resin layer, 8a, 8b ... Metal foil, 9...
・Resin plate, 10a, 10b...optical fiber,
12...Sealing resin.

Claims (1)

[Claims] 1. A light-emitting semiconductor chip and a light-receiving semiconductor chip are arranged in the same resin case, and a resin plate having metal foil on both sides is arranged between the light-emitting semiconductor chip and the light-receiving semiconductor chip, and is in contact with both metal foils. Optical fibers are arranged so that the light transmission direction is substantially perpendicular to the surface of each semiconductor chip, and the light emitted from the light emitting semiconductor chip is guided by the optical fiber and emitted from inside the resin case to the outside. A photocoupler characterized in that the photocoupler is configured to emit light to an object to be detected, guide the reflected light reflected by the object through an optical fiber, and receive the light at a light receiving semiconductor chip.