JPS6328354B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an optical coupling interrupter formed by directly attaching a chip-shaped light emitting element and a light receiving element to a substrate of a hybrid integrated circuit.

Thick-film hybrid ICs utilize film technology to form on insulating substrates to form passive elements such as resistors and conductors, and integrate active elements such as transistors and ICs or light emitting elements. The production process is
Since printing technology is the main component, the circuit configuration has a two-dimensional expansion.

For example, as shown in FIG. 1, a resistor 1 and a conductor 2 are two-dimensionally formed on a substrate 3, a semiconductor chip 4 is die-bonded on the substrate 3, and electrically connected to an electrode 6 using a very thin wire 5. It is connected to the. However, forming the optical coupling interrupter 9 by mounting the light-emitting element 7 and the light-receiving element 8 in a chip state on such a substrate 3 means that the light-emitting element 7 and the light-receiving element 8 are
This has been difficult to realize because it is necessary to make the two face each other with a gap 11 in between to allow the light shield 10 to pass through.

For this reason, in the past, the light emitting element 7 and the light receiving element 8 were individually housed in packages 12 and 13 to form one component, and these packages 12 and 13 were individually housed.
13 so that their light emitting and light receiving surfaces face each other and mounting them on the board 3 using connecting terminals, or by housing the light emitting element and the light receiving element as a pair in one package, and connecting both elements of this package. A method has been adopted in which a groove serving as a gap is provided in between, and the component is mounted on a board using a connecting terminal. In this way, the production process in which a light emitting element and a light receiving element are housed individually or in a common package to form a component and then mounted on a board has a three-dimensional configuration.
The production process is complex and it is difficult to integrate peripheral circuits, leading to high costs and making it difficult to miniaturize integrated circuits. Furthermore, since it is difficult to accurately determine the mutual arrangement of the light emitting element and the light receiving element, the accuracy as an optical coupling interrupter is also poor.

The present invention has been made in view of the above points, and involves mounting a light emitting element and a light receiving element directly on the same substrate, and molding a transparent synthetic resin onto the light emitting surface of the light emitting element and the light receiving surface of the light receiving element, respectively. The first and second convex lenses are provided, the first and second convex lenses are shielded by a horizontal part of a light shielding plate, and two vertical parts are placed on the horizontal part of the light shielding plate. are integrally provided to form a gap, and the ends of the first and second light guides made of optical cables are disposed in the holes drilled in the horizontal and vertical parts, and The light guide is made to face the end of the gap and pass through the light shield. By mounting the light-emitting element and the light-receiving element directly on the same substrate in this way, it is possible to simplify the production process such as wire bonding between these elements and electrodes, and also to mount peripheral circuits etc. on the substrate immediately adjacent to the element. The present invention facilitates miniaturization of the hybrid integrated circuit by making it possible to form a hybrid integrated circuit, and further improves the accuracy of the optical coupling interrupter by accurately determining the mutual positional relationship between the light emitting element and the light receiving element.

Hereinafter, embodiments of the present invention will be described based on the drawings from FIG. 2 onwards.

Reference numeral 14 denotes a substrate made of glass, ceramic, etc., and a resistor 15 is connected to the conductor 1 on this substrate 14.
6th grade was printed and formed into a chip shape.
A light emitting element 17 such as an LED and a light receiving element 18 such as a photodiode or phototransistor formed into a chip are directly die-bonded. These light emitting elements 17 and light receiving elements 18 are connected to electrodes 20 ₁ and 20 ₂ by ultrafine wires 19.
These electrodes 20 ₁ and 20 ₂ are connected to a peripheral circuit (not shown). Further, the light emitting surface of the light emitting element 17 is formed of plastic, glass, etc. through the first convex lens 21 and the space 22, and the shape thereof may be a pipe shape, a column shape, a bundle of fibers, etc. One end of the first light guide 23 is provided temporarily, and an inverted π-shaped light shielding plate 2 made of synthetic resin or the like is provided.
It is inserted into a hole 26 drilled in one horizontal part 25 of 4. Similarly, one end of the second light guide 29 is connected to the light-shielding plate 24 on the light-receiving surface of the light-receiving element 18 via the second convex lens 27 and the space 28.
The hole 31 of the other horizontal portion 30 is inserted into the hole 31 of the horizontal portion 30 .

These first and second light guides 23, 29
The other ends of each are inserted into holes 34 and 35 bored in the vertical parts 32 and 33 of the light shielding plate 24 so that their optical axes coincide with each other, and a gap is formed for passing the light shield 36. They are optically coupled via 37.

The first and second convex lenses 21 and 27 are
The light-emitting element 17 and the light-receiving element 18 are molded with transparent silicone resin, epoxy resin, etc. that also serves as a surface protection material, and their optical axes are aligned with the respective elements 17 and 18.
The light-emitting surface and the light-receiving surface are aligned with the central axes of the light-emitting surface and the light-receiving surface. Note that the first and second convex lenses 2
1 and 27 are, for example, light emitting elements 1 on the surface of the substrate 14.
7. After mounting the light receiving element 18 and wire bonding, a black resin layer is formed as a means for blocking external light so as to leave a circular hole 38 with a step for forming a lens on the top of these elements 17 and 18. 39 is formed, and then liquid transparent silicone resin or the like is injected into this circular hole 38 using a metering injection machine, and the hole 38 is formed by the action of the surface tension of the liquid.

That is, when the amount of liquid transparent silicone resin injected is slightly larger than the volume of the small diameter portion of the circular hole 38, the center portion swells up more than the periphery due to surface tension, forming convex lenses 21 and 27. be done.

Next, the effect will be explained.

In FIG. 2, the light emitted from the light emitting element 17 spreads radially as shown by the arrows, is condensed by the first convex lens 21, becomes a ray approximately parallel to its optical axis, and is transmitted through the space 22. The light enters one end of the first light guide 23. This incident light passes through the first light guide 23, the gap 37, the second light guide 29, and the space 28, and then passes through the second convex lens 27.
The light is focused and enters the light-receiving surface of the light-receiving element 18. In this way, the light emitted from the light emitting element 17 is sensed by the light receiving element 18, and the perforation state of the perforated tape or the like serving as the light shielding material 36 passing through the gap 37 is read.

In the above embodiment, the optical coupling interrupter is formed with one light emitting element and one light receiving element, but as shown in FIGS. 3, 4 and 5, a plurality of light emitting elements 17 ₁ are formed. , 17 ₂ , 17 ₃ ... and the light receiving elements 18 ₁ , 18 ₂ , 18 ₃ ..., respectively.
The same applies to the case where multi-channel optical coupling interrupters, which are used in pairs in parallel, are formed on the substrate. That is, the first light guides 23 1 , 23 are provided on the light emitting surfaces of the light emitting elements _{17 1} , 17 ₂ , _{17 3} . . . and the light receiving surfaces of the light receiving elements 18 1 , 18 ₂ , ₁₈ 3 .
₂ , 23 ₃ ... and the second light guide 29
₁ , 29 ₂ , 29 ₃ ... are provided, and these first and second light guides 23 ₁ , 23 ₂ , 23 ₃
The other ends of ...29 ₁ , 29 ₂ , 29 ₃ ... are inserted into holes 34 and 35 bored in the vertical parts 32A and 33A of the inverted π-shaped light shielding plate 24A so that their optical axes coincide, They are formed by optically coupling a pair of light emitting element 17 ₁ and light receiving element 18 ₁ , 17 ₂ and 18 ₂ , 17 ₃ and 18 ₃ , . . . through a gap 37, respectively.

In the present invention, as described above, a light emitting element and a light receiving element are mounted in a chip state on the same substrate of a hybrid integrated circuit to form an optical coupling interrupter. This simplifies the production process, and also enables the miniaturization of hybrid integrated circuits because resistors, conductors, or peripheral circuits can be formed on the substrate immediately adjacent to the light-emitting element or light-receiving element. Furthermore, since the light-emitting element and the light-receiving element can be mutually positioned on substantially the same plane, positioning can be performed with higher precision than in the past, and the optical coupling interrupter has high precision.

The above effects are the same when forming a multi-channel optical coupling interrupter in which a large number of pairs of light emitting elements and light receiving elements are provided.

Furthermore, since convex lenses are inserted between the light emitting element and the first light guide and between the light receiving element and the second light guide, the light emitted from the light emitting element can be effectively transmitted to the light receiving element. . Further, when a light shielding means is provided around the outer periphery of these convex lenses other than the light transmission path, an additional effect of preventing interference of light from the outside is added. The first and second convex lenses are made by molding transparent synthetic resin onto the surfaces of the light emitting element and the light receiving element.
Not only are these light-emitting elements and light-receiving elements sufficiently protected, but they can also be formed using the surface tension of the resin without the need for special convex lenses. Further, the light shielding plate is formed by molding two vertical parts into which the ends of the first and second light guides are inserted, and a horizontal part which shields the light emitting element and the light receiving element as an integrated block, and Since the gap is formed between the vertical parts of the hole, not only can manufacturing be done at low cost, but the position of the hole and the dimensions of the gap can be accurate, allowing for more accurate control.

[Brief explanation of drawings]

FIG. 1 is a side view showing a conventional example, FIG. 2 is an enlarged sectional view showing an embodiment of the optical coupling interrupter according to the present invention, and FIG. Front view,
FIG. 4 is a plan view of the same, and FIG. 5 is a side view of the same. 3, 14...Substrate, 4...Semiconductor chip, 5,
19... extra fine wire, 6,20 ₁ , 20 ₂ ... electrode,
7, 17, 17 ₁ , 17 ₂ , 17 ₃ ... light emitting element,
8, 18, _{18 1} , 18 ₂ , 18 ₃ ... light receiving element,
9... Optical coupling interrupter, 10, 36... Light shielding object, 11, 37... Gap portion, 21, 27... Convex lens, 22, 28... Space portion, 23, 23 ₁ , 2
3 ₂ , 23 ₃ , 29, 29 ₁ , 29 ₂ , 29 ₃ ... light guide, 24 ... light shielding plate.

Claims (1)

[Claims] 1. Mounting a light emitting element and a light receiving element on a substrate of a hybrid integrated circuit, optically coupling the light emitting surface of the light emitting element and the light receiving surface of the light receiving element with a light guide, and passing a light blocking object between the light guides. In an optical coupling interrupter having a gap, a plurality of sets of light-emitting elements and light-receiving elements are mounted substantially in a straight line on the substrate, and the light-emitting element and the light-receiving element are made of a transparent synthetic resin that also serves to protect the surfaces thereof. molding first and second convex lenses onto the light emitting element and the light receiving element;
The tops of these first and second convex lenses are shielded by a horizontal part of one light shielding plate, and two vertical parts are integrally provided on the horizontal part of this light shielding plate to form the gap, An end portion of the light guide made of an optical cable is inserted into a hole drilled in the horizontal portion so as to face the first and second convex lenses, and a hole drilled in the vertical portion. An optical coupling interrupter featuring: