JP2986621B2 - Transmission type optical coupling device and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure and a manufacturing method of a high-sensitivity, surface-mounted transmission optical coupling device having a lead frameless structure.

[0002]

2. Description of the Related Art FIGS. 7A to 7C show structural diagrams of a conventional transmission type optical coupling device (photo interrupter) having a lead frameless structure. A conventional transmission type optical coupling device is manufactured as follows.

[0003] First, a package (resin substrate) 1 is formed by injection molding or the like using a light-shielding and plating heat-resistant resin.
Is prepared. At this time, an H-shaped concave portion 2 is formed on the upper surface of the package (resin substrate) 1.

On the surface of the resin substrate 1, for example, Cu-Ni-Au, Ni-
A metal layer of Au or the like is formed, and thereafter, the three-dimensional wiring 3a and the element wiring pads 3b are formed by partial etching or the like.
And an electrode pad 3c. These wirings 3a,
3b and 3c are connected to soldering pads 3d on the back surface of the substrate through through holes. Here, as a method of forming a metal layer on the substrate surface, vacuum plating, sputtering, or the like can be used instead of plating.

Next, the light emitting element 4 and the light receiving element 5 are die-bonded to the element wiring pads 3b of the chambers 2a and 2b of the recess 2 with a conductive paste such as a silver paste.

After the electrodes of the elements 4 and 5 and the electrode pads 3c of the resin substrate 1 are wire-bonded with a gold wire 6 or the like, for the purpose of protecting the elements 4 and 5 and improving the external quantum efficiency, An epoxy resin 7 having high optical transmittance is injected, thermally cured, and sealed.

After the resin sealing, a light shielding layer 8 is formed on the upper surfaces of the resin substrate 1 and the sealing resin 7. This light shielding layer 8
Is realized by printing a light-shielding ink or laminating a light-shielding film or a thin plate.

Further, the central portion of the resin substrate 1, that is, between the light emitting element 4 and the light receiving element 5, is half-diced to form a groove 9
Is defined as the detection space of the detected object.

Finally, the light is divided by dicing or the like to complete a transmission type optical coupling device.

[0010]

In a conventional transmission type optical coupling device, a light-shielding layer 8 is formed by printing light-shielding ink or pasting a light-shielding film on the upper surface of a sealing resin 7. In this structure, the shape of the upper surface of the sealing resin 7 is almost flat, and there is no function of condensing the light emitted from the light emitting element 4 to the light receiving element 5. Light other than light reaching the light-receiving element 5 does not efficiently reach the light-receiving element 5. In particular, as the light receiving element 5, single crystal Si
Is used, since the light receiving surface is on the upper surface of the element 5, the light receiving surface has no sensitivity to the side light illuminating the side surface of the light receiving element 5, and reaches the light receiving element 5 directly from the light emitting element 4. The side light cannot be received, and the light use efficiency is very poor.

SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide a transmission type optical coupling device capable of improving light use efficiency.

[0012]

As shown in FIGS. 1 (A) to 1 (C) and FIG. 2, a light emitting side recess 1 for accommodating a light emitting element 12 is provided on an upper surface of a package 11 as shown in FIGS.
3, an H-shaped recess 17 including a light receiving side recess 15 for housing the light receiving element 14 and a connecting recess 16 connecting the light receiving side and the light receiving side recess 13, and the light emitting side recess 13 is provided with a thin film-shaped mounting part for mounting the light emitting element 12. A light emitting side mounting wiring section 22 and a thin film light emitting side connecting wiring section 24 connected to the light emitting element 12 via a bonding wire 23 are formed, and the light emitting element 12 is mounted on the light emitting side mounting wiring section 22. The light emitting element 12 and the light emitting side connection wiring section 24 are connected by a bonding wire 23, and a thin film light receiving side mounting wiring section 25 for mounting the light receiving element 14,
A light receiving side connection wiring portion 26 in the form of a thin film is formed on the light receiving side mounting wiring portion 25, and the light receiving element 14 is mounted on the light receiving side mounting wiring portion 25. Are connected by a bonding wire 23, and the wiring portions 22, 24, 25, and 26 are connected to external connection back terminals 31, 32, and 32 on the back surface of the package 11.
33, 34, and are connected to each other.
3 and 15 are resin-sealed with a light-transmitting sealing resin 18, a light-shielding body 19 is formed on the light-transmitting sealing resin 18 and the upper surface of the package 11, and the space between the light emitting element 12 and the light receiving element 14 is formed. In the transmission type optical coupling device in which the transmission groove 21 for the detection space of the detected object is formed by half dicing, the lower surface of the light shield 19 facing the light emitting element 12 is the light emitting element 1.
The position of the light-emitting element 12 is a paraboloid which is a focal point so that the light emitted from 2 has a lateral directivity toward the transmission groove 21, and the lower surface of the light shield 19 facing the light-receiving element 14 is The position of the light receiving element 14 is a paraboloid whose focal point is such that the light in the horizontal direction from the transmission groove 21 is focused on the light receiving element 14.

According to a second aspect, as shown in FIG. 4, a high reflectance layer 41 is formed at a boundary between the parabolic surface of the light shielding body 19 according to the first aspect and the translucent sealing resin 18. It is.

In a third aspect, as shown in FIG. 5, an air layer 42 is formed at the boundary between the parabolic surface of the light shielding body 19 according to the first aspect and the translucent sealing resin 18. .

According to a fourth aspect, on the upper surface of the package 11,
A light-emitting side recess 13 for housing a light-emitting element 12;
H-shaped recess 17 comprising a light receiving side recess 15 for accommodating the light emitting element 4 and a connecting recess 16 connecting the light receiving side recesses 4, and a thin film light emitting side mounting wiring portion for mounting the light emitting element 12 in the light emitting side recess 13. 22, a light emitting side connection wiring portion 24 in the form of a thin film connected to the light emitting element 12 via a bonding wire 23
Are formed, and the light receiving element 14 is
And a thin-film light-receiving-side connecting wiring portion 26 connected to the light-receiving element 14 via a bonding wire 23.
2, 24, 25, and 26 are routed to and connected to the external connection back surface terminals 31, 32, 33, and 34 on the back surface of the package 11, and the light emitting element 12 is mounted on the light emitting side mounting wiring portion 22; The element 12 and the light-emitting side connection wiring section 24 are connected by a bonding wire 23, the light receiving element 14 is mounted on the light receiving side mounting wiring section 25, and the light receiving element 14 and the light receiving side connection wiring section 26 are connected to the bonding wire 23. The transparent sealing resin 18 is injected into each of the recesses 13 and 15, and a through hole 35 for venting air is provided in the center portion.
Light emitted from the light emitting element 12 to the transmission groove 21 side
Downward facing the light emitting element 12 so as to have
If the surface is a paraboloid whose focus is on the position of the light emitting element 12,
In both cases, the lateral light from the transmission groove 21 is transmitted to the light receiving element 14.
The lower surface facing the light receiving element 14 is
In front of the light shield 19, which is a paraboloid focusing on the position 14
Coordinated <br/> location on the upper surface of serial translucent sealing resin 18 and the package 11, curing the light-transmissive sealing resin 18, transmural light shield 19
As remove the hole 35 as a transmission groove 21, and half-dicing between the light emitting element 12 and the light receiving element 14 is to produce a transmission grooves 21 for the detection space of the detected object.

[0016]

According to the first and fourth aspects of the present invention, since the light emitting element 12 is located at the focal point of the paraboloid of the light shield 19, when light emitted from the light emitting element 12 hits the paraboloid, All the light becomes parallel light in the horizontal direction, passes through the object detection space, and hits the paraboloid on the light receiving side. Since the paraboloid has a function of condensing parallel light at its focal point, light can be used efficiently by arranging the light receiving surface of the light receiving element 14 at the focal position.

According to the second aspect, when the high reflectivity layer 41 is formed on the paraboloid of the light shielding body 19, attenuation of light at the time of reflection is reduced.

According to the third aspect, when the air layer is formed on the paraboloid of the light-shielding body, the light hitting the paraboloid undergoes total reflection, and reaches the light receiving element without being attenuated at the time of reflection. .

[0019]

(First Embodiment) A transmission type optical coupling device (photo interrupter) according to a first embodiment of the present invention is shown in FIGS.
(C) As shown in FIG. 2 or FIG. 2, on the upper surface of the resin substrate 11 as a package, the light emitting side recess 13 for housing the light emitting element 12 is provided.
And an H-shaped recess 17 including a light receiving side recess 15 for accommodating the light receiving element 14 and a connecting recess 16 connecting the light receiving side 14 and the light emitting element 12 is housed in the light emitting side recess 13. The recesses 13 and 15 are resin-sealed with a light-transmitting sealing resin 18 for the purpose of protecting the light-emitting element 12 and the light-receiving element 14 and improving external quantum efficiency. A light-shielding body 19 is formed on the upper surface of the sealing resin 18 and the package 11, and
Half-dicing is performed between the light receiving element 2 and the light receiving element 14 to form a transmission groove 21 for a detection space of an object to be detected.

As shown in FIGS. 1 to 3, the resin substrate 11 is made of a high heat-resistant functional polymer material having good plating workability, solder heat resistance and the like, such as a liquid crystal polymer, to have light-shielding properties. Therefore, a material mixed with a powdery substance that absorbs light, such as carbon, is used. The resin substrate 11
As shown in FIGS. 3A and 3B, the light emitting element 12 and the light receiving element 1 are collectively formed on a multi-cavity substrate by injection molding or the like.
After mounting and sealing 4, the semiconductor device is divided into individual device units using a scribe method or a dicing method. In addition, the upper surface of the resin substrate 11 is coated with an ink resist 18a for preventing resin leakage of the translucent sealing resin 18.

The light-emitting side recess 13 has a structure shown in FIGS.
As shown in (C), the thin-film-shaped light-emitting-side mounting wiring section 22 on which the light-emitting element 12 is mounted, and the thin-film-shaped light-emitting-side connecting wiring section 24 connected to the light-emitting element 12 via a bonding wire 23 are made of Cu. , Ni, Au, etc., electroless plating,
It is formed three-dimensionally by electrolytic plating, etching and the like. The light receiving side recess 15 is provided with the light receiving element 14.
And a thin-film light-receiving-side connection wiring portion 26 connected to the light-receiving element 14 via a bonding wire 23 are three-dimensionally formed by three-dimensional plating.

Each of the wiring sections 22, 24, 25, 26
As shown in FIGS. 1C and 2, the wiring is routed to the external connection back surface terminals (solder pads) 31, 32, 33, 34 via the through holes 27 of the package 11.

The light emitting side mounting wiring section 22 has a structure shown in FIG.
As shown in (B), the light emitting element 12 is fixedly mounted with an Ag paste or the like, and the light emitting element 12 and the light emitting side connection wiring portion 24 are connected by a bonding wire 23. Further, the light receiving element 14 is fixedly mounted on the light receiving side mounting wiring section 25 by using an Ag paste or the like, and the light receiving element 14 and the light receiving side connection wiring section 26 are connected by the bonding wire 23.

As the translucent sealing resin 18, for example, a transparent epoxy resin having high optical transmittance is used.

The light-shielding body 19 is made of the same liquid crystal polymer as that of the resin substrate 11 and the light-transmitting sealing resin 1 is used.
Secondary mold for two primary molds (two-color molding)
Is done. The lower surface of the light shield 19 facing the light emitting element 12 is:
As shown in FIG. 1 (B), the position of the light emitting element 12 is a parabolic surface where the light is emitted from the light emitting element 12 so that the light emitting element 12 has a directivity in the lateral direction toward the transmission groove 21. 1
9 faces the light receiving element 14 so that light in the lateral direction from the transmission groove 21 is condensed on the light receiving element 14.
The position 4 is a parabolic surface that is the focus.

Further, as shown in FIG. 4B, a through hole 35 for venting air is provided in a central portion of the light shielding body 19 which is removed as the transmission groove 21.

The transmission type optical coupling device having the above configuration is manufactured as follows.

First, the resin substrate 11 is collectively formed on a multi-cavity substrate.

At this time, an H-shaped concave portion 1 including a light-emitting side concave portion 13, a light-receiving side concave portion 15, and a connecting concave portion 16 is provided on the upper surface thereof.
7 is formed in advance . The wiring portions 22, 24, 25, 26 and the back terminals 31, 3 are formed on the surface of the resin substrate 11 including the recesses 17 by using a technique such as electroless plating or electrolytic plating.
2, 33 and 34 are formed in advance. Further, the resin substrate 11
Is coated with an ink resist 18a.

Next, the elements 12 and 14 are die-bonded to the mounting wiring portions 22 and 25, and after wire bonding, for the purpose of protecting the elements 12 and 14 and improving external quantum efficiency.
As shown in FIG. 4A, the translucent sealing resin 18 is injected.

Then, as shown in FIG. 4B, a light shielding body 19 having a paraboloid is overlaid. At this time, the light-transmitting sealing resin 18 overflows through the through-hole 35 provided at the center of the light-shielding body 19 to remove air. Then, the translucent sealing resin 1
8 is heat cured in an oven.

Thereafter, as shown in FIG. 4 (C), the resin substrate 11 forms a transmission groove 21 by half-dicing between the light emitting element 12 and the light receiving element 14, which is used as a detection space of the object to be detected.

Finally, the resin substrate 11 is divided into individual units by using a scribing technique or a dicing technique, and the transmission type optical coupling device is completed.

In the transmission type optical coupling device manufactured in the above process, when a light shielding body is put on a liquid sealing resin before curing in manufacturing a transmission type optical coupling device of a leadless structure, Since air can be evacuated from the through hole in the center of the body, a step such as vacuum defoaming is not required.

In forming a groove for detecting an object by dicing, the width of the detection space can be variously changed only by changing the thickness of the blade.

In use, the light from the light-emitting element 12 to the light-receiving element 14 can be efficiently condensed by providing the light-shielding body 19 with a paraboloid. Further, the light reflected on the paraboloid and emitted to the detection space of the object is passed (collimated) as a parallel light beam, which leads to improvement in detection accuracy.

(Second Embodiment) FIG. 5 is a sectional view showing a transmission type optical coupling device according to a second embodiment of the present invention. In the transmission type optical coupling device of this embodiment, a high reflectance layer 41 having a high reflectance is formed in advance on the parabolic surface portion of the light shield 19. The high reflectivity layer 41 can be realized by metal deposition, application of glossy ink having high reflectivity, or the like.

In use, the light-shielding member 19 is provided with a function of reflecting a paraboloid, so that the light-emitting element 12
4, light can be efficiently collected.

(Third Embodiment) FIG. 6 is a sectional view showing a transmission type optical coupling device according to a third embodiment of the present invention. In the transmission type optical coupling device of the present embodiment, an air layer 42 is formed at the boundary between the parabolic surface of the light shielding body 19 and the translucent sealing resin 18. The air layer 42 can be formed by applying a release material in advance to the parabolic surface of the light-shielding body 19 and peeling off the parabolic surface when the translucent sealing resin 18 is thermally cured.

In the above configuration, the light is totally reflected at the boundary surface between the translucent sealing resin 18 and the air layer 42 during use, so that the light is transmitted from the light emitting element 12 to the light receiving element 14 as in the second embodiment. Can be efficiently collected.

It should be noted that the present invention is not limited to the above-described embodiments, and it goes without saying that many modifications and changes can be made to the above-described embodiments within the scope of the present invention.

For example, in the above embodiment, each of the wiring portions 22,
Although 24, 25, and 26 and back terminals 31, 32, 33, and 34 are formed by metal plating, vacuum deposition or sputtering may be used instead.

[0043]

As is apparent from the above description, according to the first and fourth aspects of the present invention, light is efficiently condensed from the light emitting element to the light receiving element by providing the light shield with a parabolic surface.

Furthermore, when forming a groove for detecting an object by dicing, the width of the detection space can be variously changed only by changing the thickness of the blade.

According to a second aspect of the present invention, the light shield is provided with a parabolic high reflectivity layer to reflect light, and in the third aspect, an air layer is provided on the parabolic surface of the light shield to totally reflect light. Thereby, there is an excellent effect that light can be efficiently collected from the light emitting element to the light receiving element.

[Brief description of the drawings]

FIGS. 1A and 1B are diagrams of a transmission type optical coupling device according to a first embodiment of the present invention, wherein FIG.
A sectional view, (C) is BB sectional view of (A)

FIG. 2 is a perspective view of a transmission type optical coupling device according to a first embodiment of the present invention.

FIGS. 3A and 3B are diagrams showing a resin substrate of the transmission type optical coupling device according to the first embodiment of the present invention, wherein FIG. 3A is a plan view and FIG.
Is the bottom view

FIGS. 4A and 4B are views showing a resin substrate of the transmission type optical coupling device according to the first embodiment of the present invention, wherein FIG. 4A is a sectional view after sealing resin is injected, and FIG. And (C) are cross-sectional views after dividing the resin substrate.

FIG. 5 is a cross-sectional view of a transmission type optical coupling device according to a second embodiment of the present invention.

FIG. 6 is a sectional view of a transmission type optical coupling device according to a third embodiment of the present invention.

FIG. 7 is a diagram of a conventional transmission type optical coupling device, wherein FIG.
Is a plan view, (B) is a CC sectional view of (A), and (C) is a DD sectional view of (A).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Package 12 Light emitting element 13 Light emitting side recess 14 Light receiving element 15 Light receiving side recess 16 Connecting recess 17 H-shaped recess 18 Translucent sealing resin 19 Shield 21 Transmission groove 22 Light emitting side mounting wiring part 23 Bonding wire 24 Light emitting side connection wiring Part 25 Light-receiving-side mounting wiring part 26 Light-receiving-side connection wiring part 31 to 34 Back terminal 35 Through hole 41 High-reflectance layer 42 Air layer

Claims (4)

(57) [Claims] An H-shaped recess formed on a top surface of the package, the recess including a light-emitting side housing a light-emitting element, a light-receiving side recess housing a light-receiving element, and a connecting recess connecting the light-emitting side recess and the light-emitting side recess; A thin-film-shaped light-emitting-side mounting wiring portion on which the light-emitting element is mounted, and a thin-film-shaped light-emitting-side connection wiring portion connected to the light-emitting device via a bonding wire; A light-emitting element and a light-emitting side connection wiring section are connected by a bonding wire; a thin-film light-receiving side mounting wiring section for mounting the light-receiving element in the light-receiving side recess; and a bonding wire to the light-receiving element. A light-receiving side connection wiring portion in the form of a thin film, which is connected via the light-receiving side, a light-receiving element is mounted on the light-receiving side mounting wiring portion, and the light-receiving element and the light-receiving side connection wiring portion are connected by a bonding wire. The wiring portions are connected to the external connection back surface terminal on the back surface of the package by being drawn around, and the recesses are resin-sealed with a light-transmitting sealing resin; In a transmission type optical coupling device in which a light shield is formed on an upper surface, and a halfway dicing is performed between the light emitting element and the light receiving element to form a transmission groove for a detection space of an object to be detected, The lower surface is a paraboloid where the position of the light emitting element is a focal point so that the light emitted from the light emitting element has lateral directivity toward the transmission groove side, and the lower surface of the light shield facing the light receiving element Is a parabolic surface where the position of the light receiving element is a focal point so that light in the lateral direction from the transmission groove is focused on the light receiving element. 2. A transmission type optical coupling device, wherein a high reflectivity layer is formed at a boundary between the parabolic surface of the light shielding body according to claim 1 and a translucent sealing resin. 3. A transmissive optical coupling device, wherein an air layer is formed at a boundary between the parabolic surface of the light-shielding body according to claim 1 and a translucent sealing resin. 4. An H-shaped recess including a light-emitting side recess for housing a light-emitting element, a light-receiving side recess for housing a light-receiving element, and a connecting recess for connecting the light-emitting side recess and the light-emitting side recess on the upper surface of the package. A thin-film light-emitting side mounting wiring portion for mounting the light-emitting element, and a thin-film light-emitting side connection wiring portion connected to the light-emitting element via a bonding wire; Forming a thin-film light-receiving-side mounting wiring portion for mounting the element, and a thin-film light-receiving-side connection wiring portion connected to the light-receiving element via a bonding wire; A light emitting element is mounted on the light emitting side mounting wiring portion, and the light emitting element and the light emitting side connection wiring portion are connected by a bonding wire, and the light receiving element is mounted on the light receiving side mounting wiring portion. Equipped with Connecting the light-receiving element and the light-receiving-side connection wiring section with a bonding wire, injecting a light- transmitting sealing resin into each of the concave portions, providing a through hole for venting air at a central portion, and
The light emitted from the element has a lateral directivity to the transmission groove side.
So that the lower surface facing the light emitting element
It is a paraboloid that is the focal point, and the side from the transmission groove
Facing the light receiving element so that the light in the direction
Shielding with a paraboloidal bottom surface focusing on the position of the light receiving element
Body was placed on the upper surface of the translucent sealing resin and the package, curing the light-transmissive sealing resin, so as remove the through-hole of the light shielding member as a transmission groove, between the light emitting element and the light receiving element A method for manufacturing a transmission-type optical coupling device, comprising forming a transmission groove for a detection space of an object to be detected by half dicing.