JPS6012296Y2 - optical coupler - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an optical coupler that is easy to manufacture, has high signal transmission efficiency, and is easy to use with an automatic insertion machine.

Conventionally, in an optical coupler in which a light emitter and a photoreceptor are arranged facing each other and signals are transmitted by sending and receiving light, the lead wires 102 and 103 are folded in a complicated manner as shown in Figure 1. 106 and 107 were opposed to each other, and the outer shape corresponded to the integrated circuit package (dashed line).

Although such an optical coupler has a standardized size and shape as a component and has high signal transmission efficiency, the lead wire 102
, 103 are bent in multiple directions without cutting the thin metal wires 108, 108 for wiring, making manufacturing extremely complicated and resulting in poor yield.

In addition, even though the size and shape have been standardized, automatic insertion machines for integrated circuits are much more complex and expensive than those for passive circuit components, so when the number of boards is small, It was difficult to introduce an automatic insertion machine when there were only a small number of integrated circuits to be loaded onto the board.

The present invention has been developed to overcome these drawbacks, and the present invention will be described in detail below based on examples.

FIG. 2 is a cross-sectional view of the optical coupler according to the embodiment of the present invention.
3. 4 is a lead wire arranged substantially parallel to the same plane.

The ends of the lead wires 1, 2, 3.4 are twisted so that they are arranged in a V-shape in the promotion case 5.

6 and 7 are optical semiconductors capable of transmitting and receiving light, such as light emitting diodes and phototransistors, respectively, and the lead wires 1.
2. 3. The tips of the lead wires 2 and 3 located in the center of 4 are placed and fixed on the inner side of the V-shape, and the outer lead wires 1 and 4 are wired with thin metal wires 8 and 8, respectively. ing.

An optical coupler having such a structure can be easily manufactured as follows.

First, a thin plate mainly made of copper or iron for a lead frame is punched, etched, etc. to form a lead frame in a desired shape as shown in FIG. 3a.

This lead frame has a set of four lead wires 1' and 2'.
, 3', 4' are connected and held together by connecting lines 9, 9',
Paired connecting wires 10, 10, . . . for connecting only two lead wires are provided on the tip side of the thin connecting wire 9'.

A conductive adhesive such as silver paste is applied by printing to desired locations on the tips of the lead wires 1', 2', 3', and 4' to form optical semiconductor devices such as light emitting diodes 6' and phototransistors 7'. Cure the conductive adhesive.

After the optical semiconductor is fixed, it is bonded using wire bonding method etc.
Wiring is performed using thin metal wires 8' and 8' (see Figure 3).

For example, in the conventional optical coupler shown in Fig. 1, optical semiconductor devices were either mounted on both sides of one lead frame, or two lead frames were used. It is very easy to work because only one side of the lead frame is needed.

Next, the thin connecting wire 9' of this lead frame is clamped and fixed with a fixing jig, and the paired connecting wire 10.10 is pressed with a triangular pressing jig.
...Press only.

As a result, the tips of the two lead wires on each side of the center are twisted so that the optical semiconductors are placed inside.

After this, the pair connecting line 10 is
, 10 . . . and lead wire 1'.

2', 3', and 4' are twisted in a fixed manner, and at least the paired connecting lines 10, 10, . . . are cut.

The lead frame shaped in this manner is shown in FIG. 3C.

At the tip of the lead frame formed in this way, a fourth
As shown in FIG. 2, an optical coupler as shown in FIG. 2 is formed by covering the corner portion with an outer case 5' having a filler 11.11.

The space 12 defined by the outer case 5' and the filling material 11.11 has a substantially triangular shape, on two sides of which the lead wires 1', 2', 3', 4' are located.

In addition, the outer case 5' and the filling material are made of white resin,
The peripheral wall of the space 12 serves as a reflective surface due to plating applied to necessary locations.

As a method of not using such an outer case 5', as shown in FIG. 12
' may be molded and the surrounding area may be covered with white resin 15.

To show such an optical coupler more specifically, lead wires 1', 2', 3', and 4' are 20 rm long and punched from a thin plate with a thickness of 0.6 mm, and the intervals between the lead wires are as follows. 0.1
inch (approximately 25 mm).

The thin connecting line 9' is provided at a position 611Un from the tip, and the distance between the thin connecting line 9' and the paired connecting lines 10, 10, . . . is 2.5M.

With this spacing, even if the lead wire is twisted by 120 degrees, it will not break and will not recover.

The light emitting diode 6' is a gallium phosphorus light emitting diode with a side of 0.3 mm, and the phototransistor 7' has a surface with a side of 0.3 mm.
．． It is a silicon Darlington type phototransistor with a square shape of 877EIl.

Lead wire 1'. The angle between 2' and lead wires 3' and 4' is 8
A range of 0 degrees to 135 degrees is preferable.

It is more preferable to slightly change the twisting method so that the light emitting diode 6' is located approximately at the center of the surface of the phototransistor 7' as shown in FIG.

In any case, when twisting the lead wire, pair connecting wire 10,
Since force is applied only to 10, no pressure is transmitted or tension is applied to the thin metal wires 8', 8', etc.

Furthermore, the light emitted from the side surface of the light emitting diode 6' directly reaches the light receiving surface of the phototransistor 7'. Since the reflected light reaches the light-receiving surface of the phototransistor 7', the light can be transmitted and received through a much shorter optical path than in a rectangular space, resulting in less loss.

As described above, the present invention includes a plurality of lead wires whose tips are arranged in an eight-shape shape and whose lead portions are arranged substantially parallel within the same plane.
It is an optical coupler that includes an optical semiconductor placed inside the figure-8 shape at the tip of the lead wire, and a reflective surface that surrounds the optical semiconductor and has a triangular cross-section with the figure-8 arrangement as two sides. There is no need for complicated work such as complicated bending of lead wires, and there is no tension applied to the thin metal wires, so manufacturing can be done at a high yield. Light is transmitted from one side of the triangular room to the other, so signal transmission efficiency is also high. Also, since the lead wires are aligned in one plane in the same direction and can be spaced evenly if necessary, an automatic insertion machine can be easily used in the same way as passive circuit components such as resistor arrays.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a lead frame of a conventional optical coupler, FIG. 2 is a sectional view of an embodiment of the present invention, and FIG. 3a. 4b and 4c are plan views of a lead frame for explaining the manufacturing process of the optical coupler of the present invention, and FIGS. 4a and 4b are sectional views of the optical coupler of the present invention. 1.2, 3.4... Lead wire, 5...
Outer case, 6,7 optical semiconductor.

Claims (1)

[Scope of utility model registration request] A plurality of lead wires whose tips are arranged in a V-shape and whose lead portions are arranged substantially parallel in the same plane, an optical semiconductor placed inside the V-shape at the tips of the lead wires, and a 1. An optical coupler characterized by having a triangular cross section with two sides arranged in a letter shape, and comprising a reflective surface surrounding an optical semiconductor.