JP3143351B2 - Reflective optical coupling device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is applied to small OA equipment, precision equipment, and the like. The light emitted from a light emitting chip is reflected by an object to be detected in front of the light emitting chip to detect the light by a light receiving chip. The present invention relates to a reflection type optical coupling device (reflection type photo interrupter) for discriminating the presence / absence of an object without contact.

[0002]

2. Description of the Related Art The structure of a conventional reflection type optical coupling device will be described with reference to FIGS. 6 (a) to 6 (d) are plan views, and FIGS. 6 (e) to 6 (h) are plan views of the reflection type optical coupling device according to the conventional example. E in area e of the plan view
It is -E 'sectional drawing.

FIGS. 7A and 7B are structural views of a conventional reflection type optical coupling device. FIG. 7A is a plan view, FIG. 7B is a front view, and FIG. It shows the F 'cross-sectional view.

As shown in FIG. 6, in the conventional optical coupling device, a light emitting chip 1 is mounted on a light emitting side lead terminal 3 of a multiple lead frame 10 and a light receiving chip 2 is mounted on a light receiving side lead terminal 4, and the other light emitting side is connected. Electrical connection is made to the bonding areas of the light-receiving side lead terminals 5 and 6 from the two chips 1 and 2 using the gold wire 9 (FIGS. 6A and 6E).

Next, both chips 1 and 2 are individually coated with a light-transmitting resin 11 by a transfer molding method to form a light-emitting-side light-transmitting resin body 12 and a light-receiving-side light-transmitting resin body 13 [FIG. 6 (b), (f)].

The light-transmitting resin body 16 is formed by integrally molding the periphery of the two light-transmitting resin bodies 12 and 13 with a light-shielding resin 15 by a transfer molding method or an injection molding method using a molding die.

At this time, the window 18 through which the light emitted from the light emitting chip 1 passes and the window 19 through which the light entering the light receiving chip 2 passes are not covered with the light-shielding resin 15 [FIGS. 6 (c) and 6 (g)]. )].

Further, the tie bar portions 8 and 8 'are cut,
By performing lead forming as required, individual finished products shown in FIG. 7 are obtained.

At this time, by covering the surroundings of the two light-transmitting resin bodies 12 and 13 with the light-shielding resin 15, the two light-transmitting resin bodies 12 and 13 are arranged side by side at a fixed interval to prevent separation. [FIG. 6 (d), (h)].

[0010]

Due to the optical characteristics, the light-shielding resin body 16 shown in FIG. 7 is such that the light emitted from the light emitting chip 1 passes through the light-emitting side light-transmitting resin body 12 and is directly transmitted to the light-receiving side. There is no problem as long as the light-shielding wall 16 ′ exists between the light-emitting side light-transmitting resin body 12 and the light-receiving side light-transmitting resin body 13 so as not to enter the transparent resin body 13.

However, in the conventional reflection-type optical coupling device, as shown in FIG. 7, the light-emitting side translucent resin body 12 and the light-receiving side translucent resin body 13 are juxtaposed at a fixed interval, and are mechanically fixed so as not to be separated from each other. In order to secure the strength, the entire periphery of both translucent resin bodies 12 and 13 is covered with a light-shielding resin 15 except for the windows 18 and 19 which are the light entrance and exit sections. As described above, the light-shielding resin 1 extends to unnecessary portions (indicated by N1, N2 and N3) in terms of optical characteristics as described above.
5 that sufficiently satisfies the strong demand for miniaturization and thinning of the reflection type optical coupling device accompanying the high-density mounting of OA equipment and precision equipment on which the reflection type optical coupling device is mounted. Was not.

Here, the outer diameter of the package of the conventional reflection type optical coupling device in the horizontal direction (L1), the vertical direction (W1) and the height direction (H1) is, for example, 4 mm × 3 mm × 1.
In this case, the dimension of the light-shielding resin body 16 at a portion not required due to optical characteristics is N1 ×
2 = about 0.6 mm, vertical direction is N2 × 2 = 0.6 mm
The ratio N3 is about 0.4 mm in the height and height directions, which accounts for a large proportion of the outer diameter, which hinders miniaturization and thinning.

Further, in the conventional reflection type optical coupling device, since the formation of the light-shielding resin body is performed by the transfer molding method or the injection molding method, a molding die is required, which causes an increase in cost.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a reflection type optical coupling device which is significantly smaller and thinner than conventional products.

[0015]

To achieve the above object, a reflection type optical coupling device according to the present invention has a pair of a light emitting side lead terminal and a light receiving side lead terminal, and one of the light emitting side lead terminals. And a lead frame in which one of the light-receiving side lead terminals is connected via a connection frame portion, and a light-emitting chip and a light-receiving chip bonded to the light-emitting side and light-receiving side lead terminals of the lead frame, respectively. By molding each of the chips independently with a light-transmitting resin, a light-emitting side light-transmitting resin body and a light-receiving side light-transmitting resin body are juxtaposed on both sides of the connection frame portion at a constant interval. Formed between opposing side surfaces of the two translucent resin bodies juxtaposed at a fixed interval ,
Opposite side surfaces of the two translucent resin bodies and the connection frame
Liquid light-blocking resin is injected into the space surrounded by the
And a light- shielding substance which is a light-shielding resin body .

[0016]

Further , the reflection type optical coupling device of the present invention comprises
With a light emitting side lead terminal and a light receiving side lead terminal
One of the light emitting side lead terminals and the light receiving side lead end
One terminal of the child is connected via the connection frame
Lead frame and the light emitting side of the lead frame
And light-receiving lead terminals respectively
Light-emitting chip and light-receiving chip, and both chips are independent
And molding with a translucent resin
Light emission juxtaposed at regular intervals on both sides of the frame
A certain distance between the side translucent resin body and the light receiving side translucent resin body
Opposing side surfaces of the two translucent resin bodies juxtaposed with
A liquid light shielding property is provided in a space formed between the auxiliary frame, which is formed between the connecting frame and is bent at an angle of about 90 degrees, and which is surrounded by the connecting frame and the opposing side portions of the light transmitting resin bodies. It is characterized by being a light-shielding resin body in which a resin is injected and cured.

Further , the reflection type optical coupling device of the present invention comprises
With a light emitting side lead terminal and a light receiving side lead terminal
One of the light emitting side lead terminals and the light receiving side lead end
One terminal of the child is connected via the connection frame
Lead frame and the light emitting side of the lead frame
And light-receiving lead terminals respectively
Light-emitting chip and light-receiving chip, and both chips are independent
And molding with a translucent resin
Light emission arranged at regular intervals on both sides of the frame
A certain distance between the side translucent resin body and the light receiving side translucent resin body
Opposing side surfaces of the two translucent resin bodies juxtaposed with
A metal wall or a light-shielding resin wall mounted on a connection frame between opposing side surfaces of both light-transmitting resin bodies formed therebetween .

[0019]

According to the reflection type optical coupling device of the present invention having the above-described structure, since the light-shielding substance is interposed only between the light-emitting side light-transmitting resin body and the light-receiving side light-transmitting resin body, the conventional example is used. The size and thickness can be significantly reduced as compared with.

Further, since the lead frame in which the light emitting side lead terminal and the light receiving side lead terminal are connected by the connection frame portion is used, the light receiving side translucent resin body and the light emitting side translucent resin body are spaced at a predetermined interval. To ensure sufficient strength so as not to separate from each other.

Further, since the amount of the light-shielding resin can be reduced as compared with the conventional example, the cost can be reduced.

Further, since the formation of the light-shielding resin body is not performed by using a mold, the mold is unnecessary.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In a reflection type optical coupling device according to the present invention, a light emitting chip and a light receiving chip are mounted on a lead frame in which one light emitting side lead terminal and one light receiving side lead terminal are connected by a connection frame portion. Are molded independently with a light-transmitting resin to form a light-emitting side light-transmitting resin body and a light-receiving side light-transmitting resin body, and a light-shielding substance is interposed only between the two light-transmitting resin bodies. It was made.

Hereinafter, a detailed description will be given with reference to the drawings.

In the embodiment, the same symbols are given to the same functional parts as in the conventional example.

1 (a) to 1 (d) are plan views, and FIGS. 1 (e) to 1 (h) are plan views of a reflection type optical coupling device according to a first embodiment of the present invention. FIGS. 3A to 3D are cross-sectional views taken along the line AA ′ in a region a of the plan views. FIG.
FIGS. 3A and 3B are diagrams showing the structure of a reflection type optical coupling device according to a first embodiment of the present invention, wherein FIG. 3A is a plan view, FIG. 3B is a front view, FIG. FIG. 4D is a plan view of FIG.
It is B 'sectional drawing.

Referring to FIG. 2, a method of manufacturing the reflection type optical coupling device according to the first embodiment of the present invention will be described.

First, the light emitting chip 1 is connected to the light emitting side lead terminal 3 of the multiple lead frame 10 in which the light emitting side lead terminal 3 and the light receiving side lead terminal 6 are connected by the connection frame portion 7, and the light receiving side lead terminal 4 receives the light. The chip 2 is mounted, and the light emitting chip 1 is electrically connected to the other light emitting side lead terminal 5 and the light receiving chip 2 is electrically connected to the other light receiving side lead terminal 6 by an Au wire 9 or the like.

Here, 8, 8 'are multiple lead terminals 3,
A tie bar portion for connecting 4, 5, and 6.

In this embodiment, the light emitting side lead terminal 3 on which the light emitting chip 1 is mounted and the light receiving side lead terminal 6 which is wire-bonded by the Au wire 9 or the like are connected by the connection frame portion 7. The light-emitting-side lead terminals 5 wire-bonded with the wires 9 and the light-receiving-side lead terminals 4 on which the light-receiving chip 2 is mounted may be connected by the connection frame portion 7 (FIGS. 1A and 1E).

Next, the light emitting chip 1 and a part of the light emitting side lead terminals 3 and 5, and the light receiving chip 2 and a part of the light receiving side lead terminals 4 and 6 are each independently made of a translucent resin such as epoxy resin. The light-emitting side light-transmitting resin body 12 and the light-receiving side light-transmitting resin body 13 are formed by performing molding using a transfer molding method or the like using 11.

At this time, as the shape of the two translucent resin bodies 12 and 13, the protrusions 14 are provided at both ends of the opposing side faces, so that the distance between the opposing side faces of the two translucent resin bodies 12 and 13 is provided. Is small at both ends and relatively large at the center [FIGS. 1 (b) and (f)].

Next, a liquid light-shielding resin 15 is potted by a potting method in a space surrounded by the connecting frame 7 on the bottom surface and the opposing surfaces of the light-transmitting resin bodies 12 and 13 including the projections 14 on the side surfaces. By filling, the light-shielding resin body 16 is formed [FIGS. 1 (c) and 1 (g)].

Finally, the tie bars 8, 8 'connecting the lead terminals 3, 4, 5, 6 and the like are cut, and if necessary, are led out from the light-transmitting resin bodies 12, 13. By forming the lead terminals 3, 4, 5, and 6, which are formed, a single product is completed as shown in FIG. [FIG. 1 (d),
(H)].

Here, as the light-shielding resin 15, for example, a thermosetting epoxy resin is used. This light-shielding resin 1
In the filling method of No. 5, the main component of the thermosetting epoxy resin and the curing agent are mixed, agitated, defoamed, and then dispensed to the opposing surfaces of the translucent resin bodies 12 and 13 and the connection frame 7. The defoamed liquid epoxy resin is injected into the enclosed space. Thereafter, by heating, the injected epoxy resin, which is a liquid thermosetting resin, is cured, and the light-shielding resin body 16 is formed.

In the above-mentioned filling method, a two-component epoxy resin comprising a main agent and a curing agent is used, but a one-component epoxy resin may be used.

The reason why the distance between the two light-transmitting resin bodies 12 and 13 is relatively large (about 0.5 mm) at the center (C2) is that the liquid light-shielding resin 15 is injected with a dispenser. This is to secure a region into which the tip of the dispenser can be inserted.

The distance (C1) between the opposing projections 14 at both ends of both translucent resin bodies 12, 13 is 0.15 to 0.15.
It is good to be 0.3 mm, preferably about 0.2 mm.

The reason is that if C1 is about 0.2 mm, the liquid light-shielding resin 15 is injected into the space surrounded by the opposing surfaces of the light-transmitting resin bodies 12 and 13 and the connection frame 7. In this case, the liquid light-shielding resin 1
5 does not flow out, and the liquid light-shielding resin 15 can be injected into a desired space.

In view of the light blocking that prevents light emitted from the light emitting chip 1 from directly reaching the light receiving chip 2, the thickness (C1) of the light shielding resin 15 is 0.15 m.
m is enough.

This can be proved by the following experimental results.

When a transmission type optical coupling device is used and the thickness of the light-shielding resin wall is 0.15 mm, light emitted from the light-emitting chip is generated in the light-receiving chip by light reaching the light-receiving chip through the light-shielding resin wall. Output is photocurrent Ic = 22 nA
(Forward current IF of light emitting chip = 10 mA, C of light receiving chip
−E voltage VCE = 5 V). This value is 100 n which is a general allowable value of the dark current ICEO (IF = 0 mA).
Within A, it can be seen that the light is completely blocked.

3 (a) to 3 (e) are plan views, and FIGS. 3 (f) to 3 (e) are plan views of a reflection type optical coupling device according to a second embodiment of the present invention. FIGS. 7A and 7B are cross-sectional views taken along the line CC ′ in a region c of the plan views of FIGS.

FIGS. 4A and 4B show the structure of a reflection type optical coupling device according to a second embodiment of the present invention. FIG. 4A is a plan view, FIG. 4B is a front view, and FIG. () Is a side view, and (d) is a cross-sectional view taken along line DD 'of the plan view.

A method of manufacturing a reflection type optical coupling device according to a second embodiment of the present invention will be described with reference to FIG.

First, a pair of light emitting side lead terminals 3 and 5 and a pair of light receiving side lead terminals 4 and 6 are provided. One light emitting side lead terminal 3 and one light receiving side lead terminal 6 are connected by a connection frame 7. The light emitting chip 1 is connected to the light emitting side lead terminals 3 of the multiple lead frames 10 which are connected and include auxiliary frames 17, 17 'extending from the connection frame portion 7 to the tie bar portions 8, 8'. The light receiving chip 2 is mounted on the terminal 4, and the other light emitting side lead terminal 5
And the other of the light-receiving side lead terminals 6 from the light-receiving chip 2
Electrical connection is made by the u-line 9 or the like.

Incidentally, similarly to the first embodiment, the light emitting side lead terminal 5 and the light receiving side lead terminal 4 may be connected by a connection frame 7 (FIGS. 3A and 3F).

Next, the light emitting chip 1 and a part of the light emitting side lead terminals 3 and 5 and the light receiving chip 2 and a part of the light receiving side lead terminals 4 and 6 are each independently made of a light shielding resin 11 such as an epoxy resin. The light-emitting side translucent resin body 12 and the light-receiving side translucent resin body 13 are formed by molding using a transfer molding method or the like, as shown in FIG.
(G)].

Next, unnecessary portions of the tie bar portions 8, 8 'are cut, and the light emitting side lead terminals 3, 5 and the light receiving side lead terminals 4, 6 are separated from the auxiliary frames 17, 17' [FIG.
(C), (h)].

Thereafter, the auxiliary frames 17, 17 'are bent at an angle of about 90 degrees to the side where the light-shielding resin bodies 12, 13 are formed [FIGS. 3 (d), (i)].

Next, a liquid light-shielding space is formed in the space surrounded by the connecting frame portion 7 on the bottom surface and the auxiliary frames 17 and 17 'whose side surfaces are bent and the opposing surfaces of the two translucent resin bodies 12 and 13. The light-blocking resin body 16 is filled with the light-blocking resin 15.
Is formed. As the light shielding resin 15, for example, a thermosetting epoxy resin is used.

The method for filling the light-shielding resin 15 is as follows.
The description is omitted because it is the same as that of the embodiment [FIG.
(J)].

Here, the bent auxiliary frames 17 and 1
7 ′ and the gap between the translucent resin bodies 12 and 13 (0.1
(About 5 mm to 0.3 mm), the liquid light-shielding resin 15 does not flow out of the space due to the surface tension of the injected liquid light-shielding resin 15.

Lastly, the frames (not shown) connected in series are cut, and if necessary, the two translucent resin bodies 1 are cut.
Lead terminals 3, 4, which are led out from 2, 13
Forming of 5 and 6 results in a single product as shown in FIG.

As described above, according to the reflection type optical coupling devices of the first and second embodiments of the present invention, the light transmitting side light transmitting resin body 12 and the light receiving side light transmitting resin are Since the distance between the members 13 is fixed and the light-shielding resin member 16 is formed only between the two light-transmitting resin members 12 and 13, the same strength as that of the conventional reflection type optical coupling device is ensured and greatly increased. It is possible to achieve the miniaturization and thinning.

For example, the horizontal direction (L2) and the vertical direction (W) of the package of the reflection type optical coupling device of the first and second embodiments.
2) and the outer diameter dimension in the height direction (H2) is 3.6 mm
The size is about 2.4 mm x 1.3 mm, and the package volume can be reduced by about 45% as compared with the conventional reflection type optical coupling device.

Further, the amount of the light-shielding resin is reduced to about 1/7 as compared with the conventional product.

Further, since the light-shielding resin body conventionally formed by a mold is formed by a potting method, a mold is not required.

FIGS. 5A and 5B show the structure of a reflection type optical coupling device according to a third embodiment of the present invention. FIG. 5A is a plan view, FIG. 5B is a front view, and FIG. ) Is a side view.

The reflection type optical coupling device of the third embodiment uses a lead frame having the same shape as that of the first embodiment, and attaches a light emitting chip and a light receiving chip to the lead terminals 3 and 4 in the same manner as in the first embodiment. Mount, Au on lead terminals 5 and 6 from both chips
Electrical connection is made by wires or the like, and thereafter, the light-emitting side and the light-receiving side are each independently molded with the light-shielding resin 11 to form the light-emitting-side translucent resin body 12 and the light-receiving-side translucent resin body 13. I do. At this time, the protrusions 14 made of the translucent resin shown in FIG.
Is not provided.

Thereafter, an adhesive 20 is applied on the connection frame 7 exposed between the two translucent resin bodies 12 and 13, and a light-shielding made of metal or light-shielding resin is applied to a region where the adhesive 20 is applied. The wall 21 is mounted, and the adhesive 20 is cured by heating, and the light shielding wall 21 is fixed. As the adhesive 20, for example, an epoxy-based thermosetting resin is used.

The light-shielding wall 21 made of metal or light-shielding resin prevents light emitted from the light-emitting side light-transmitting resin body 12 from directly entering the light-receiving side light-transmitting resin body 13.

[0063]

As described above, the reflection-type optical coupling device of the present invention uses a lead frame in which one light-emitting side lead terminal and one light-receiving side lead terminal are connected by a connection frame portion. Since the light-blocking substance is interposed only between the opposing side surfaces of the light-transmitting resin body and the light-receiving-side light-transmitting resin body, the light-emitting-side light-transmitting resin body and the light-receiving-side light-transmitting resin body are spaced at a fixed interval. , And while ensuring sufficient strength so as not to separate from each other, a significant reduction in size and thickness can be achieved as compared with the conventional example. In other words, O, which is a device mounted with the reflection type optical coupling device,
It can sufficiently cope with high-density mounting of A equipment and precision equipment.

The amount of resin forming the light-shielding resin body is
Since it can be reduced to about 1/7 as compared with the conventional example, the cost of the reflection type optical coupling device can be reduced.

Further, since the formation of the light-shielding resin body is not performed by using a mold, this mold is unnecessary.

[Brief description of the drawings]

FIGS. 1A to 1D are manufacturing process diagrams of a reflective optical coupling device according to a first embodiment of the present invention, wherein FIGS.
(E) to (h) are cross-sectional views of (a) to (d).

2 (a) is a plan view, FIG. 2 (b) is a front view, FIG. 2 (c) is a side view, and FIG. 2 (d) is a cross-sectional view taken along line BB 'of the plan view. It is.

FIGS. 3A to 3E are manufacturing process diagrams of a reflection type optical coupling device according to a second embodiment of the present invention, wherein FIGS.
(F) to (j) are cross-sectional views of (a) to (e).

4 (a) is a plan view, FIG. 4 (b) is a front view, FIG. 4 (c) is a side view, and FIG. 4 (d) is a sectional view taken along line DD 'of FIG. It is.

5 (a) is a plan view, FIG. 5 (b) is a front view, and FIG. 5 (c) is a side view of a reflection type optical coupling device according to a third embodiment of the present invention. .

6 (a) to 6 (d) are plan views, and FIGS. 6 (e) to 6 (h) are cross-sectional views of FIGS. 6 (a) to 6 (d). It is.

7 (a) is a plan view, FIG. 7 (b) is a front view, and FIG. 7 (c) is a sectional view taken along line FF 'of the plan view.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 light emitting chip 2 light receiving chip 3, 4 light emitting side lead terminal 5, 6 light receiving side lead terminal 7 connection frame part 10 lead frame 11 light transmitting resin 12 light emitting side light transmitting resin 13 light receiving side light transmitting resin 16 Light-shielding resin body

──────────────────────────────────────────────────続 き Continuation of front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01L 31/12

Claims (3)

(57) [Claims] 1. A connecting frame portion for connecting a pair of light emitting side lead terminals, a pair of light receiving side lead terminals, and one terminal of the pair of light emitting side lead terminals to one terminal of the pair of light receiving side lead terminals. A light-emitting chip and a light-receiving chip bonded to the light-emitting side and light-receiving side lead terminals of the lead frame, respectively; and molding the both chips independently with a light-transmitting resin. Accordingly, a light emitting side translucent resin body and a light receiving side translucent resin body juxtaposed at both sides of the connection frame portion at regular intervals, and opposing side surfaces of the both translucent resin bodies juxtaposed at regular intervals. Formed between the opposite light-transmitting resin bodies
Light-shielding resin in the space surrounded by the side and the connection frame
And a light- shielding substance, which is a light-shielding resin body that has been injected and cured . 2. A pair of light emitting side lead terminals and a pair of light receiving sides.
A lead terminal and one of the pair of light emitting side lead terminals.
Terminal and one of the pair of light-receiving side lead terminals.
Lead frame composed of connection frame parts to be connected
And the light emitting side and light receiving side lead terminals of the lead frame.
Light-emitting chip and light-receiving chip
And the two chips are independently molded with a transparent resin.
With this, a fixed interval is provided on both sides of the connection frame portion.
Light-emitting side translucent resin body and light-receiving side translucent juxtaposed
Relative to the transparent resin body and the two translucent resin bodies juxtaposed at a certain interval.
The auxiliary frame formed between the connecting side surfaces and extending from the connecting frame and bent at an angle of about 90 degrees, and the surrounding side surfaces of the connecting frame and the opposing side portions of the light-transmitting resin bodies. reflective optical coupling device which characterized by including injecting a light-shielding resin in the space, the light-shielding material is a cured light shielding resin body. 3. A pair of light emitting side lead terminals and a pair of light receiving sides.
A lead terminal and one of the pair of light emitting side lead terminals.
Terminal and one of the pair of light-receiving side lead terminals.
Lead frame composed of connection frame parts to be connected
And the light emitting side and light receiving side lead terminals of the lead frame.
Light-emitting chip and light-receiving chip
And the two chips are independently molded with a transparent resin.
With this, a fixed interval is provided on both sides of the connection frame portion.
Light-emitting side translucent resin body and light-receiving side translucent juxtaposed
Relative to the transparent resin body and the two translucent resin bodies juxtaposed at a certain interval.
Formed between the side surface of, characterized by being provided with a light-shielding material is mounted on the metal wall or a light-shielding resin wall on the connection on the frame between the opposite sides of both translucent resin member Reflective optical coupling device.