JPH1093132A - Photocoupler - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize smallsized and thin-type product, without deteriorating its reliability. SOLUTION: The photocoupler comprises a substrate 32 having a pair of emitting side plated wirings 30a, 30b and pair of light-receiving side plated wirings 31a, 31b, light-emitting element connected to the emitting side wiring 30a, a photodetecting element 34 connected to the receive side wiring 31, a transparent resin block 35 which molds both elements 33, 34 with a transparent resin in a single body, and recesses 36, formed by cutting the resin block 35 off between these electrodes 33 and 34 to optically separate them. The recesses 36 has a screen 37 for blocking the light from direct incidence on the photodetecting electrode from the emitting element 33.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical coupling device for detecting an object to be detected by light without contact.

[0002]

2. Description of the Related Art A conventional reflection type optical coupling device is shown in FIGS. As a first conventional example, as shown in FIG. 7, a pair of gold-plated wirings 1a and 1a for light emission and light reception are used.
The light emitting element 4 and the light receiving element 5 are die-bonded to the substrate 3 on which b, 2a, and 2b have been formed, and are internally connected by gold wires 6, respectively. Next, a substrate 8 having holes 7 corresponding to the light-emitting side and the light-receiving side is bonded together, and a light-transmitting resin 9 is poured into the holes 7 by potting and sealed. At this time, the light emitting element 4 and the light receiving element 5 are optically separated by the light shielding wall 10 of the substrate 8. The substrates 3 and 8 are vertically and horizontally cascaded as shown by long dashed lines in the plan view, and thereafter, each one cut out by dicing becomes a product.

FIG. 8 shows a second conventional example. A pair of gold-plated wirings 11a and 11 for light emission and light reception
b, 12a, and 12b on the three-dimensional substrate 13
Then, the light receiving element 5 is die-bonded and internally connected with the gold wire 6, respectively, and the light transmitting resin 14 is poured into the space where the light emitting element 4 and the light receiving element 5 are die bonded by potting and sealed. At this time, the substrate 13
The light emitting element 4 and the light receiving element 5 are optically separated by the light shielding wall 15. The substrates 13 are vertically and horizontally cascaded as shown by long dashed lines in the plan view, and then each product cut out by dicing becomes a product.

FIG. 9 shows a third conventional example. Lead terminal 1
The light emitting element 4 and the light receiving element 5 are bonded to 6a and 17a, respectively, and connected to the lead terminals 16b and 17b facing the respective lead terminals 16a and 17a by the gold wire 6. One terminal 16a of the light-emitting side lead terminal and one terminal 17b of the light-receiving side lead terminal are connected via a connection frame portion 18. These lead terminals 16
In this state, a, 16b, 17a, and 17b are connected to adjacent similar sections by tie bars to form a multiple connection. A lead frame in which each of the elements 4 and 5 is bonded and connected by a gold wire 6 is independently molded on a light emitting side and a light receiving side with a light transmitting resin by transfer molding to form a light emitting side and a light receiving side light transmitting resin body. 1
9 and 20 are formed. Thereafter, the two translucent resin bodies 19, 2
The light-shielding resin 21 is poured into the space surrounded by the opposing side surfaces of the “0” and the connection frame 18 by potting. Further, the tie bar is cut, and the lead terminals 16a, 16b, 1
7a and 17b are formed into individual products.

[0005]

In the first and second conventional reflection type optical coupling devices, light is directly transmitted from the light emitting element to the light receiving element between the light receiving side and the light emitting side due to the optical characteristics of the product. There is no problem if a light shielding wall exists so as not to enter. However, in the conventional reflection type optical coupling device, since a liquid translucent resin is poured to cover the light receiving and emitting elements, a frame is provided to prevent the translucent resin from flowing out in addition to the light shielding wall. Is required, which hinders miniaturization and thinning of the package.

In the optical coupling device of the third conventional example, the package body has a light-shielding resin only between the light receiving side and the light emitting side, which is necessary for optical characteristics, so that miniaturization can be achieved.
The lead terminals protrude outside the package, which increases the mounting area. These lead terminals are insert-molded and fixed in a light-transmitting resin, and a light-transmitting epoxy resin is usually used as the light-transmitting resin. Since the softening point of this resin due to heat is about 100 to 150 ° C, the temperature of the package rises due to the heat of the solder when soldering the product, and even if a slight force is applied to the lead terminals, Relatively displaced,
There is a problem that the internal gold wire is broken or the lead terminal comes off from the package, which lowers the reliability of the product.

Also, in the transmission type optical coupling device, since the light emitting element and the light receiving element are mounted on separate lead terminals and are molded with a translucent resin, heat at the time of soldering or protrusion of the lead terminals. As a result, the above-described problems of miniaturization, thinning, and reliability arise.

SUMMARY OF THE INVENTION In view of the above, it is an object of the present invention to provide an optical coupling device which has improved reliability of a product, and has been reduced in size and thickness.

[0009]

Means for solving the problems according to the present invention include a substrate on which a light emitting side wiring and a light receiving side wiring are formed, a light emitting element connected to the light emitting side wiring, and a light emitting element connected to the light receiving side wiring. Light-receiving element, a light-transmitting resin body obtained by molding both elements with a light-transmitting resin, and the light-transmitting resin body is cut between them to separate the light-emitting element and the light-receiving element. And a dent formed by the above method.

When this is a reflection type optical coupling device, a light shielding body for preventing light from directly entering the light receiving element from the light emitting element is provided in the recess. Further, the light-shielding body is made higher than the light-transmitting resin body to completely eliminate light passing through the recess from the light-emitting side light-transmitting resin body and entering the light-receiving side light-transmitting resin body.

In the case of a transmission type optical coupling device, a reflection wall is provided on each of the light-transmitting resin bodies on the light-emitting side and the light-receiving side so that light emitted from the light-emitting element passes through the recess and reaches the light-receiving element. An optical path is formed at

Further, in order to prevent light from transmitting from the light-emitting side to the light-receiving side via the translucent resin body, the recess is formed so as to reach a part of the substrate. Thereby, the light emitting side and the light receiving side are completely separated.

According to the optical coupling device having the above structure,
Using a board with wiring, a light-transmitting resin body is molded and a recess is provided between the light-emitting side and the light-receiving side, so lead terminals are eliminated, and the board will be directly mounted. Solder heat resistance is obtained, and product reliability does not decrease. In addition, since the light-transmitting resin body is formed by molding on the substrate, there is no frame member or lead terminal from around the light-transmitting resin body, so that the size and thickness can be reduced.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A reflection type optical coupling device according to an embodiment of the present invention will be described with reference to FIGS. This reflection type optical coupling device includes a substrate 32 on which a pair of light-emitting side plating wirings 30a and 30b and a pair of light-receiving side plating wirings 31a and 31b are formed, a light emitting element 33 connected to the light emitting side plating wiring 30a, and a light receiving element. A light-receiving element 34 connected to the side plating wiring 31a; a light-transmitting resin body 35 formed by integrally molding the two elements 33 and 34 with a light-transmitting resin;
A recess 36 formed by cutting a light-transmitting resin body 35 between the light-receiving element 3 and the light-receiving element 34 to optically separate the light-receiving element 3 from the light-receiving element 34.
And a light shielding body 37 for preventing light from directly entering the light receiving element 34 from the light emitting element 33 is provided in the recess 36.

The substrate 32 is a single insulating long plate,
A pair of wirings of the light emitting side plating wirings 30a, 30b and the light receiving side plating wirings 31a, 31b are opposed to each other, and are plated with gold which also serves as an electrode from the upper surface of the substrate 32 to the lower surface via the side surface. Also, the light-emitting side plating wiring 30
The a and 30b and the light-receiving-side plating wirings 31a and 31b are adjacent to each other in the longitudinal direction to form a single section, which is arranged at a constant interval to form a multiple section. The plated region of the side surface in the width direction of the substrate 32 is slightly depressed, and when this optical coupling device is mounted on a circuit board or the like by soldering, the solder should not spread outside the device. ing.

The light-transmitting resin body 35 includes a light-emitting side light-transmitting resin body 35a covering the light-emitting element 33 and the light-emitting side plating wirings 30a and 30b, a light-receiving element 34, and a light-receiving side plating wiring 31.
a, 31b, which cover the light receiving side, and are separated by a recess 36 formed between them.

The dent 36 is formed by cutting the translucent resin body 35 in the width direction with a dicing saw so as to form a concave shape, and bites into the substrate 32 by a depth L (≒ 0.05 mm). As a result, the light-transmitting resin body 35 is cut off, and the light-emitting side and the light-receiving side are completely separated from each other, so that light from the light-emitting element 33 propagates inside the light-transmitting resin body 35 and Will not be reached.

The light-shielding body 37 is a light-shielding wall formed by filling a recess 36 with a light-shielding resin such as a thermosetting epoxy resin. The light-shielding body 37 is formed of a light-transmitting light-transmitting resin body 35a and a light-receiving light-transmitting resin body 35b. It is surrounded by opposing sides and substrate 32. The upper surface is d slightly smaller than each translucent resin body 35.
(≒ 0.1 mm). Further, the side surface in the width direction is tapered, and protrudes outward from the translucent resin body 35. By making the light shielding body 37 one size larger than the translucent resin body 35, the light shielding body 37 passes directly from the light emitting side translucent resin body 35a to the light receiving side translucent resin body 35b through the recess 36. Light is blocked.

A method for manufacturing the optical coupling device having the above configuration will be described. First, each plating wiring 30a, 30b, 31a, 31b
Plating wirings 30a and 31a on the substrate 32 on which
The light emitting element 33 and the light receiving element 34 are mounted by die bonding, respectively, and the other plating wirings 30b and 31b are mounted.
The light emitting element 33 and the light receiving element 34 are respectively connected by wire bonding with gold wires 38.

This is integrally molded with a translucent epoxy resin by transfer molding. In this state, the light-emitting side translucent resin body 35a and the light-receiving side translucent resin body 35b are not yet separated. Next, an intermediate portion between the light-emitting side and the light-receiving side of the light-transmitting resin body 35 is removed by dicing to form a recess 36, and the light-transmitting resin body 35a and the light-receiving side light-transmitting resin body 35b are separated. I do. At this time, both resin bodies 35
In order to completely separate a and 35b, the substrate 32 is also removed by a depth L by dicing.

Subsequently, a light-shielding body 37 is formed in the recess 36 so as to protrude from the light-transmitting resin body 35 by injection molding using a light-shielding resin. Finally, by dicing the substrate 32 together, adjacent similar sections are separated, and each product is manufactured one by one. After the appearance inspection and the characteristic inspection, the products are shipped.

The optical coupling device is surface-mounted on a circuit board of a small device such as an OA device by a solder reflow device, and the light emitted from the light emitting element 33 is blocked by the light shield 37 and directly goes to the light receiving element 34. However, it is used as a reflection type photo interrupter that detects the presence or absence of an object without contact by detecting the light reflected on the object to be detected in front by the light receiving element 34.

As described above, since the lead terminal is eliminated and the light-shielding member 37 is provided only between the light-transmitting resin bodies 35a and 35b on the light-emitting side and the light-receiving side, there is no adverse effect due to heat during soldering. , Does not reduce the reliability of the product. Moreover, there is no lead terminal on the side of the molded translucent resin body 35, and no substrate or the like serving as a frame when the translucent resin is poured is required.
It can be made thinner. In addition, due to the small size and thinness, materials used such as resin can be reduced, and the number of molds can be increased to improve production efficiency, leading to cost reduction.

Further, since the recess 36 is formed not by molding the translucent resin but by cutting the translucent resin body 35 by dicing or the like, the structure of the mold is simplified. Thus, the cost and time required for processing the mold can be reduced, and the cost can be reduced.

Here, the external dimensions of the package of the optical coupling device of the first conventional example are 3.4.times.3.7.times.
1.3 mm, the external dimensions of the package of the second conventional optical coupling device are 2.4 × 3.2 × 1.1 mm, and the external dimensions of the package of the third conventional optical coupling device are 3.0 mm. 6x
Although the dimensions are 2.4 × 1.3 mm, the outer dimensions of the optical coupling device of the present invention are 2.1 × 2.2 × 1.0 mm, which can achieve a significant reduction in size and thickness.

While the embodiment as a reflection type optical coupling device has been described above, a transmission type optical coupling device will be described as an applied embodiment. In this optical coupling device, as shown in FIG. 4, a substrate 3 on which a pair of light-emitting side plating wires 30a, 30b and a pair of light-receiving side plating wires 31a, 31b are formed.
2 and the light emitting element 3 connected to the light emitting side plating wiring 30a
3 and the light receiving element 3 connected to the light receiving side plated wiring 31a
4, a light-transmitting resin body 35 in which both elements 33 and 34 are integrally molded with a light-transmitting resin, and a light-transmitting resin between them to separate the light emitting element 33 and the light receiving element 34. Body 3
5 is formed by cutting. Here, a substrate 32 thicker than that of the reflection type is used.
Reflection walls 40, 41 are provided on the light-transmitting resin bodies 35a, 35b on the light-emitting side and the light-receiving side, respectively. Light emitted from the light-emitting element 33 is reflected by the light-reflecting side reflection wall 40, passes through the recess 36, and receives light. An optical path P is formed so that the light is reflected by the side reflection wall 41 and reaches the light receiving element 34.

Light-transmitting resin body 35 on light-emitting side and light-receiving side
A and 35b are simultaneously formed into a shape in which a part of the upper surface is tapered at an angle θ at the time of transfer molding, and these are used as reflection walls 40 and 41. Note that the outer surfaces of the reflecting walls 40 and 41 are preferably covered with a light-shielding resin or a metal film such as aluminum so that light is easily reflected. Further, the reflecting walls 40 and 41 may be formed by cutting, grinding, or the like after forming, instead of using transfer molding.

FIG. 5 shows a method of manufacturing the optical coupling device having the above configuration.
As shown in (1), the process from die bonding the light emitting element 33 and the light receiving element 34 to forming the recess 36 by dicing and separating the light emitting element 33 and the light receiving element 34 into the light emitting side and the light receiving side is the same as the case of the reflection type optical coupling device.

However, when the light emitting side and the light receiving side are separated by dicing, the substrate 32 is set at L '(≧ 0.5 mm).
Just get rid of. In this way, by using the thick substrate 32 and removing it deeply, it is possible to secure the passage of the object without increasing the external dimensions of the package in the height direction.

Finally, adjacent sections are cut off in the same manner as in the case of the reflection type, and one product is obtained. Therefore, also in the optical coupling device of the present embodiment, the same effects as those of the above embodiment can be achieved.

The optical coupling device is surface-mounted on a circuit board of a small device such as an OA device by a solder reflow device, and is used as a transmission type photo interrupter. That is, the light emitted from the light emitting element 33 is reflected by the reflection wall 40 and passes through the recess 36. At this time, if there is an object in the dent 36, the light is blocked and does not reach the light receiving element 34, and if there is no object to be detected, the light passes through the dent 36 and
Then, the light is reflected toward the light receiving element 34 and is detected by the light receiving element 34, so that the presence or absence of the passage of the object can be identified without contact.

It should be noted that the present invention is not limited to the above-described embodiment, and it goes without saying that many modifications and changes can be made to the above-described embodiment within the scope of the present invention. For example, in a reflection type optical coupling device, instead of forming a light shielding body by injection molding using a light shielding resin,
As shown in FIG. 6, a light-shielding body 42 made of metal or light-shielding resin is separately formed, and an adhesive is applied onto the substrate 32 exposed in the recess 36, and the light-shielding body 42 is mounted. May be fixed.

When forming the dents, cutting may be performed by applying a laser beam or an ultra-high pressure water flow instead of dicing.

[0034]

As is apparent from the above description, according to the present invention, the lead terminals are eliminated by using a board with wiring, so that the board is directly mounted, and the transparency due to heat at the time of soldering is obtained. There is no adverse effect on the translucent resin body such as softening of the optical resin, and the reliability of the product is not reduced. In addition, a recess is provided between the light-transmitting resin body on the light-emitting side and the light-receiving side, and only the light-shielding body is provided in the recess as necessary, so that the light-transmitting resin body projects beyond the side of the light-transmitting resin body. This eliminates the need for lead terminals and substrates, thereby realizing compactness and thinning. In addition, due to the small size and thinness, materials used such as resin can be reduced, and the number of molds can be increased to improve production efficiency, leading to cost reduction.

[Brief description of the drawings]

FIGS. 1A and 1B are diagrams showing a reflection type optical coupling device according to an embodiment of the present invention, wherein FIG. 1A is a plan view, FIG. 1B is a side view, and FIG.

FIG. 2 is a manufacturing process diagram of the same.

FIG. 3 is a flowchart of the same manufacturing process.

4A and 4B are diagrams showing a transmission type optical coupling device, wherein FIG. 4A is a plan view and FIG.

FIG. 5 is a flowchart of the same manufacturing process.

6A and 6B are diagrams showing another reflection type optical coupling device, and FIG.
Is a plan view, (b) is a side view

FIGS. 7A and 7B are diagrams showing a first conventional reflection type optical coupling device, wherein FIG. 7A is a plan view and FIG.

8A and 8B are views showing a reflection type optical coupling device of a second conventional example, wherein FIG. 8A is a plan view, and FIG.

FIGS. 9A and 9B are diagrams showing a third conventional example of a reflection type optical coupling device, wherein FIG. 9A is a plan view and FIG.

[Explanation of symbols]

 30a, 30b Light-emitting side plating wiring 31a, 31b Light-receiving side plating wiring 32 Substrate 33 Light-emitting element 34 Light-receiving element 35 Translucent resin body 36 Depression 37 Light-shielding body

Claims (5)

[Claims] A substrate on which a light-emitting side wiring and a light-receiving side wiring are formed; a light-emitting element connected to the light-emitting side wiring; a light-receiving element connected to the light-receiving side wiring; A light-transmitting resin body molded with a light-emitting element and a light-receiving element, in order to separate the light-emitting element and the light-receiving element from each other. Characteristic optical coupling device. 2. The optical coupling device according to claim 1, wherein a light shielding body for preventing light from directly entering the light receiving element from the light emitting element is provided in the recess. 3. The optical coupling device according to claim 2, wherein the light shielding body is made higher than the translucent resin body. 4. A light-transmitting resin body on each of a light-emitting side and a light-receiving side is provided with a reflecting wall, and an optical path is formed so that light emitted from the light-emitting element passes through the recess and reaches the light-receiving element. The optical coupling device according to claim 1, wherein 5. The optical coupling device according to claim 1, wherein the recess reaches a part of the substrate.