JP3489979B2 - MOS-FET output 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 MOS-FET output optical coupling device and a method of manufacturing the same, and more specifically,
The present invention relates to a small-input type small-sized MOS-FET optical coupling element having stable electric characteristics and quality and a manufacturing method thereof.

[0002]

2. Description of the Related Art A relay for switching a connection of a modem device to a telephone line is shifting from a conventional electromagnetic relay to a semiconductor relay in order to achieve high reliability and non-contact. Especially, a MOS-
In recent years, the development of FET output optical coupling elements has been rapidly advanced. Further, as the modem device is made smaller and thinner, the elements used are also required to be smaller and thinner.

5A and 5B show a conventional MOS-FE.
The structure of a T output optical coupling element is shown. As shown in FIG. 1B, the pair of upper and lower lead frames 1 and 1 are formed into an L shape by bending a metal plate material, and one ends thereof vertically oppose each other.

As shown in FIGS. 1A and 1B, a light emitting element 2, a photoelectric conversion element 3 and a MOS-FET 4 are die-bonded to the opposing surfaces of the lead frames 1 and 1. More specifically, the light emitting element 2 is die-bonded to the facing surface of the upper lead frame 1, and the photoelectric conversion element 3 and the MOS-FET 4 are die-bonded to the facing surface of the lower lead frame 1. Since this MOS-FET output optical coupling element is a bidirectional output type MOS-FET output optical coupling element, the MOS-FET 4 is provided on both left and right sides of the photoelectric conversion element 3.

In addition, a gold wire 5 is wire-bonded to these elements 2, 3 and 4. A light path (docking path) 6 made of a transparent resin such as a silicone resin is formed between the light emitting element 2 and the photoelectric conversion element 3. The light path 6 is formed in a shape in which the diameter gradually increases toward the lower side. The above-mentioned elements and members are molded with the light-shielding epoxy resin 7.

Next, referring to FIG. 6, the conventional MOS-F described above is used.
The process of shipping the ET output optical coupling device will be described.
First, the light emitting element 2 is attached to the lead frames 1 and 1 having the above shapes
The photoelectric conversion element 3 and the MOS-FETs 4 and 4 are die-bonded. Next, after wire bonding is performed with the gold wire 5, a transparent resin is filled between the light emitting element 2 and the photoelectric conversion element 3 to thereby form the light path 6. Subsequently, molding is performed with the light-shielding epoxy resin 7.

Thereafter, as shown in FIG. 6, exterior plating,
Lead forming, dielectric strength test, electrical characteristic test,
Marking and visual inspection are performed, and then the product is packaged before shipping.

The above manufacturing process is performed by the same process regardless of the difference in package (DIP, SOP).

[0009]

The conventional MOS-FET output optical coupling device described above has the following problems.

(1) Problems caused by the shape of the docking path 6 When the docking path 6 is formed between the light emitting element 2 and the photoelectric conversion element 3 with a silicone resin or the like and light is transmitted, the docking according to the conventional technique is performed. Change in viscosity of resin forming path 6,
The shape of the docking path 6 is difficult to stabilize due to variations in viscosity, variations in angle when injecting resin, and the like, and almost all reflected light from the side surface of the light emitting element 2 is included in the photoelectric conversion element 3.
Is not transmitted to.

For example, as shown in FIGS. 7A and 7B, when the amount of resin forming the docking path 6 is small, the edge 8 of the photoelectric conversion element 3 is exposed from the docking path 6, and the exposed edge is exposed. 8 may be cracked.

The photoelectric conversion element 3 has a structure in which a plurality of light receiving cells are arranged in series. Due to the structure, the required voltage cannot be obtained unless the entire light receiving portion receives light.

Further, the photoelectric conversion element 3 is, as described above,
Although it is necessary to receive a larger amount of light in the entire light receiving portion and convert it into a voltage, the MOS-FET 4 has a drawback that malfunction (leakage) occurs when receiving light.

Therefore, as shown in FIGS. 8A and 8B, when the amount of resin is large, the docking path 6 forming between the light emitting element 2 and the photoelectric conversion element 3 has MOS-FETs 4 and 4.
The light from the light-emitting element 2 flows to the side, and the MOS-FETs 4 and 4
To the MOS-FETs 4 and 4, resulting in poor characteristics.

(2) Problems Caused by Wiring Between Optoelectronic Element 2 and MOS-FET 4 FIG. 9 shows the internal wiring diagram and wire layout of a general MOS-FET output optical coupling element (bidirectional output type). Indicates. As shown in FIG. 9, the photoelectric conversion element 3 and the MOS-FET
4 and 4 need to be electrically connected, and if a dummy lead is not used, it is necessary to hit a wire between chips. It should be noted that it is impossible to make dummy leads if the package does not have enough space as in the SOP type.

In the case of hitting a wire between chips, generally, in the second bonding, the stress applied to the bonding portion is larger than that in the first bonding, so that the size of the chip pad and the thickness of the pad are restricted. It's done.

Therefore, when the second bonding is performed on the chip pad, the adjustment in the process becomes difficult as compared with the general wire bond between the chip and the lead, and the process yield is lowered.

The present invention has been made in view of the above circumstances, and provides a MOS-FET output optical coupling element and a method of manufacturing the same, which have stable electric characteristics and quality and can improve the yield. The purpose is to do.

Another object of the present invention is to provide a small input type small-sized MOS-FET optical coupling element and a manufacturing method thereof.

Another object of the present invention is to provide a method of manufacturing a MOS-FET output optical coupling device which can reduce the number of steps and correspondingly improve the manufacturing efficiency.

[0021]

Means for Solving the Problems MOS-FET of the present invention
In the output optical coupling element, a plating pattern is provided on a pair of injection-molded resin substrates, a light-emitting element is mounted on one injection-molded resin substrate, and a photoelectric conversion element and a MO light-emitting element are mounted on the other injection-molded resin substrate.
A MOS-FET output optical coupling device having a structure in which an S-FET is mounted and both injection-molded resin substrates are bonded to each other through a translucent resin, wherein each injection-molded resin substrate has at least two walls. parts are respectively provided, the light emitting element and the between the two walls in each of the injection molding resin substrate
Each photoelectric conversion element is arranged, and the photoelectric conversion element is arranged.
The outer wall of the injection-molded resin substrate placed on the
The MOS-FET is arranged between the wall and
A plating pattern is provided between the photoelectric conversion element and the MOS-FET.
Are provided, the plating pattern and the photoelectric conversion element
And the MOS-FET are wire-bonded respectively.
In addition, inclined reflecting surfaces that efficiently transmit the reflected light from the side surface of the light emitting element to the photoelectric conversion element are formed on the facing surfaces of the respective wall portions located on both sides of the light emitting element. The above object is achieved.

Preferably, the photoelectric conversion element is arranged.
Both sides of the photoelectric conversion element of the other injection molded resin substrate
From the side surface of the light emitting element to the facing surface of each wall portion located at
Tilt reflection that efficiently transmits the reflected light of the
Each of the shooting surfaces is formed .

Further, it is preferable that the inclined reflection surface of the injection-molded resin substrate is plated with a material having high reflection efficiency.

[0024] Preferably, the front end surfaces of the wall portions formed on the both injection-molded resin substrates are in close contact with each other when the both injection-molded resin substrates are attached to each other. .

[0025]

Preferably, the MOS-FET is arranged on both sides of the photoelectric conversion element.

A method of manufacturing a MOS-FET output optical coupling element according to the present invention is a MOS-type device according to any one of claims 1 to 6.
A method of manufacturing a FET output optical coupling element, comprising: die-bonding a light emitting element to a facing surface of one injection-molded resin substrate; and photoelectric conversion element and MOS on a facing surface of another injection-molded resin substrate.
-The step of die-bonding the FET and the wire-bonding to these elements, the step of bonding both injection-molded resin substrates through the translucent resin, the step of dividing the bonded substrates into chips, and then And a step of performing an inspection such as a dielectric strength test, thereby achieving the above object.

The operation of the present invention will be described below.

As described above, at least one injection-molded resin substrate is provided with at least two wall portions, the light emitting element is disposed between the two wall portions, and the side surface of the light emitting element is provided on the opposite surface of the wall portion. According to the configuration in which the inclined reflection surface that efficiently transmits the reflected light of the photoelectric conversion element is formed, the utilization efficiency of the reflected light guided to the photoelectric conversion element can be improved.
Does not cause a characteristic defect due to the leakage. In addition, a small input current type small MOS-FET
There is also an advantage that an output optical coupling element can be realized.

Further, according to the construction in which the wall portion and the inclined reflecting surface are formed on the other injection-molded resin substrate and the photoelectric conversion element is mounted between the wall portions, the efficiency of utilizing the reflected light can be further improved. A FET output optical coupling element can be realized.

Further, according to the configuration in which the inclined reflecting surface is plated with a material having high reflection efficiency, the attenuation of light can be reduced, so that the reflected light from the light emitting element can be guided to the photoelectric conversion element more efficiently. it can. For this reason, a low input current type small-sized MOS-FE with more stable characteristics.
A T output optical coupling element can be realized.

Further, according to the construction in which the wall portions are formed on the both injection-molded resin substrates, and when the both injection-molded resin substrates are bonded together, the front end surfaces of the both wall portions are in close contact with each other, the light emitting element and the MOS Since the -FET output optical coupling element is optically blocked by the wall portion, light from the light emitting element does not leak to the MOS-FET. Therefore, since the MOS-FET does not malfunction, the MOS-FET having excellent electrical characteristics is used.
A FET output optical coupling element can be realized.

Further, according to the structure in which the plating pattern is formed between the photoelectric conversion element and the MOS-FET, the 2nd bonding is performed on the plating pattern.
The wire between the chips can be deleted, and the wire bonding process can be stabilized accordingly, so that the product yield can be improved.

Further, according to the configuration in which the MOS-FET is arranged on both sides of the photoelectric conversion element, the bidirectional output type MOS is provided.
A FET output optical coupling device can be realized.

[0035]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be specifically described below with reference to the drawings.

(Embodiment 1) FIGS. 1 and 2 show the MO of the present invention.
1 shows Embodiment 1 of an S-FET output optical coupling element. First,
The structure of the MOS-FET output optical coupling element will be described with reference to FIG. In this MOS-FET output optical coupling element, an injection-molded resin substrate 9 to which the light emitting element 2 is die-bonded and an injection-molded resin substrate 9 to which the photoelectric conversion element 3 and the MOS-FETs 4 and 4 are die-bonded are made of a silicone resin or the like. It is manufactured by pasting together through the light-sensitive resin 6. As a material for the injection molded resin substrates 9 and 9, for example, liquid crystal polymer may be used.

Each of the injection-molded resin substrates 9 and 9 has a U-shape in a front sectional view, and two wall portions 10 and 10 are provided upright in the middle portion in the left-right direction thereof. The facing surfaces (horizontal facing surfaces) of the two wall portions 10 and 10 are formed as inclined surfaces 10 ′ and 10 ′ that become narrower toward the tip. A gap is formed between the upper and lower wall portions 10 and 10 when the two injection-molded resin substrates 9 and 9 are bonded to each other.

Two walls 1 of the upper injection-molded resin substrate 9
The light emitting element 2 is die-bonded between 0 and 10. That is, the light emitting element 2 is die-bonded to the bottom surface of the recess formed by the two wall portions 10 and 10. In addition, the light emitting element 2
A wire bond is made with a gold wire 5.

Inclined surface 1 formed on the walls 10 and 10.
0 ′ and 10 ′ are formed in order to efficiently guide the reflected light from the light emitting element 2 to the photoelectric conversion element 3. That is, the inclination angles of the inclined surfaces 10 ′ and 10 ′ are selected so that the reflected light from the light emitting element 2 (particularly the side surface thereof) can be efficiently guided to the photoelectric conversion element 3.

In the first embodiment, in order to guide the reflected light to the photoelectric conversion element 3 more efficiently, the inclined surface 10 ',
10 'is provided with a plating 11 made of a material having high reflection efficiency such as gold plating, palladium plating, silver plating and the like. That is, when such plating 11 is applied, the attenuation of light can be reduced, and the reflected light can be guided to the photoelectric conversion element 3 more efficiently.

On the other hand, the wall portion 1 of the lower injection-molded resin substrate 9
The photoelectric conversion element 3 is die-bonded between 0 and 10. Further, MOS-FETs 4 and 4 are die-bonded on the left and right sides thereof. That is, the MOS-FET 4 is die-bonded between the wall portion 10 and the outer wall of the injection-molded resin substrate 9. For the same reason as above, plating 11 is also applied to the inclined surfaces 10 'and 10' of the wall portions 10 and 10 of the lower injection-molded resin substrate 9.

The photoelectric conversion element 3 and the MOS-FET
Wire bonds are applied to the wires 4 and 4 with a gold wire 5.

In the above structure, the direct light from the light emitting element 2 is directly transmitted to the light receiving portion of the photoelectric conversion element 3. Further, the light from the side surface of the light emitting element 2 is transmitted to the light receiving portion of the photoelectric conversion element 3 by the inclined surface 10 ′ formed on the wall portions 10 of the upper and lower injection molded resin substrates 9, 9.

Next, the MOS of the first embodiment will be described with reference to FIG.
The manufacturing process of the -FET output optical coupling element will be described.

Similar to the above-mentioned conventional example, the light emitting element 2 and the photoelectric conversion element 3 are provided on the corresponding portions of the upper and lower injection molded resin substrates 9, 9.
Then, the MOS-FETs 4 and 4 are die-bonded, and subsequently, a gold wire 5 is wire-bonded to these elements.

Next, the upper and lower injection-molded resin substrates 9 and 9 are attached to each other with a translucent resin 6 such as a silicone resin interposed therebetween.

Next, the bonded substrates are divided into individual chips by the dicing process. Then, for each of the divided chips, withstand voltage test, electrical characteristic test,
Marking and visual inspection are performed, and then the product is packaged before shipping.

When the manufacturing method of the present invention is compared with the conventional manufacturing process shown in FIG. 6, the welding process of the metal frame, the docking forming process, the molding process, the exterior plating process and the lead forming process are unnecessary, and the bonding process is added. Therefore, the number of steps can be significantly reduced as compared with the conventional method.

Therefore, according to the method of the present invention, there is an advantage that the manufacturing efficiency can be improved and an inexpensive MOS-FET output optical coupling element can be provided.

In the first embodiment, the upper and lower injection-molded resin substrates 9 and 9 are provided with the inclined surfaces 10 'on the walls 10, but only the wall 10 of the upper injection-molded resin substrate 9 is formed. Since the utilization efficiency of the reflected light guided to the photoelectric conversion element can also be improved by the configuration of forming the inclined surface 10 ′, such an embodiment is also within the scope of application of the present invention.

(Embodiment 2) FIG. 3 shows the MOS-FE of the present invention.
Embodiment 2 of a T output optical coupling element is shown. The MOS-FET output optical coupling element of the second embodiment is the same as the MOS-FET output optical coupling element of the first embodiment except that the heights of the wall portions 12 formed on the upper and lower injection-molded resin substrates 9, 9 are different. It has a configuration of. Therefore, the same reference numerals are given to corresponding parts, duplicated description will be omitted, and only different points will be described below.

As shown in FIG. 3, the height of the wall portion 12 is the same as the height of the outer wall in both the upper and lower injection-molded resin substrates 9 and 9.
The tip surfaces of 2 and 12 are in close contact with each other.

Therefore, the photoelectric element 3 and the MOS-FET are
The walls 4 and 4 are optically separated from each other. Therefore, the light from the light emitting element 2 is emitted from the MOS-FET 4,
Since there is no leakage to the MOS-FET 4, the MOS-FETs 4 and 4 do not malfunction.

Therefore, according to the second embodiment, it is possible to realize a MOS-FET output optical coupling element having excellent electrical characteristics.

In the second embodiment as well, the wall portion 12
It is possible to apply the plating 11 to the inclined surface 12 ′.

Further, the MOS-FET output optical coupling element of the second embodiment is manufactured by the process shown in FIG. Similarly, the MOS-FET output optical coupling element of the third embodiment, which will be described next, is also manufactured by the same process.

(Third Embodiment) FIG. 4 shows the MOS-FE of the present invention.
Embodiment 3 of a T output optical coupling element is shown. The MOS-FET output optical coupling element according to the third embodiment includes a photoelectric element 3 and a MOS.
The configuration is the same as that of the first and second embodiments except that the plating patterns 13 and 13 are formed between the -FETs 4 and 4. Corresponding parts are designated by the same reference numerals, and overlapping description will be omitted. In FIG. 4, the wall portion 10
Etc. are omitted.

In the MOS-FET output optical coupling element of the third embodiment, 2nd is formed on the plating patterns 13 and 13.
Bonding is performed, thereby removing the chip-to-chip wire.

Therefore, the MOS-FET of the fourth embodiment is
According to the output optical coupling element, since the wire bonding process can be stably and easily performed correspondingly, there is an advantage that the yield of products can be improved.

[0060]

According to the above MOS-FET output optical coupling element of the present invention, at least one injection-molded resin substrate,
At least two wall portions are provided, the light emitting element is arranged between the two wall portions, and an inclined reflection surface that efficiently transmits light reflected from the side surface of the light emitting element to the photoelectric conversion element is formed on the opposite surface of the wall portion. According to this configuration, the utilization efficiency of the reflected light guided to the photoelectric conversion element can be improved, so that characteristic defects due to leakage of the MOS-FET do not occur. In addition, there is an advantage that a small input current type MOS-FET output optical coupling element can be realized.

In particular, the MOS-FET according to claim 2
According to the output light coupling element, since the wall portion and the inclined reflection surface are formed on the other injection-molded resin substrate and the photoelectric conversion element is mounted between the wall portions, the utilization efficiency of reflected light is further improved. A possible MOS-FET output optical coupling device can be realized.

In particular, the MOS-FET according to claim 3
According to the output light coupling element, since the inclined reflection surface is plated with a material having high reflection efficiency, the attenuation of light can be reduced, so that the reflected light from the light emitting element can be more efficiently converted into a photoelectric conversion element. I can guide you. Therefore, the characteristics are much more stable, and the low input current type small MO
An S-FET output optical coupling device can be realized.

In particular, the MOS-FET according to claim 4
According to the output optical coupling element, since the wall portions are formed on the both injection-molded resin substrates, and when the both injection-molded resin substrates are bonded together, the tip surfaces of the both wall portions are in close contact with each other, the light emission is improved. Since the element and the MOS-FET output optical coupling element are optically blocked by the wall portion, light from the light emitting element does not leak to the MOS-FET. Therefore, MOS-FET
Does not cause a malfunction, it is possible to realize a MOS-FET output optical coupling element having excellent electrical characteristics.

In particular, the MOS-FET according to claim 5
According to the output optical coupling element, the photoelectric conversion element and the MOS-FE
Since the plating pattern is formed between T, by performing the 2nd bonding on this plating pattern, the wire between the chips can be deleted, and the wire bonding process can be performed stably and easily by that amount. The product yield can be improved.

In particular, the MOS-FET according to claim 6
According to the output optical coupling element, since the MOS-FET is arranged on both sides of the photoelectric conversion element, a bidirectional output type MOS-FET output optical coupling element can be realized.

Further, according to the method of manufacturing the MOS-FET output optical coupling element of the present invention, the MOS-F having the above-mentioned effects is obtained.
The ET output optical coupling element can be manufactured in a small number of steps, and the manufacturing efficiency can be improved. As a result, the cost of the MOS-FET output optical coupling element can be reduced.

[Brief description of drawings]

FIG. 1 is a front sectional view showing a structure of a MOS-FET output optical coupling element according to a first embodiment.

FIG. 2 is a process flow chart showing a manufacturing process of the MOS-FET output optical coupling element according to the first embodiment.

FIG. 3 is a front sectional view showing the structure of a MOS-FET output optical coupling device according to a second embodiment.

FIG. 4 is a front sectional view showing a structure of a MOS-FET output optical coupling element according to a third embodiment.

5A and 5B show a structure of a conventional MOS-FET output optical coupling device, FIG. 5A is a front sectional view, and FIG. 5B is a side view.

FIG. 6 is a process flow chart showing a manufacturing process of a conventional MOS-FET output optical coupling element.

FIG. 7 is a diagram for explaining a problem of a conventional MOS-FET output optical coupling element, (a) is a front sectional view,
(B) is a side view.

FIG. 8 is a diagram for explaining another problem of the conventional MOS-FET output optical coupling element, (a) is a front sectional view,
(B) is a side view.

FIG. 9 is a diagram showing an internal connection diagram and a wire layout of a general MOS-FET output optical coupling element.

[Explanation of symbols] 2 light emitting element 3 Photoelectric conversion element 4 MOS-FET 5 gold wire 9 Injection molded resin substrate 10 and 12 walls Inclined surface formed on the 10 'and 12' walls 11 Plating on inclined surface 13 Plating pattern

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

Claims (6)

(57) [Claims] 1. A pair of injection-molded resin substrates are provided with plating patterns, one injection-molded resin substrate is mounted with a light emitting element, and the other injection-molded resin substrate is provided with a photoelectric conversion element and a MOS.
-A MOS-FET output optical coupling device having a structure in which an FET is mounted and both injection-molded resin substrates are bonded together via a translucent resin, wherein each injection-molded resin substrate has at least two wall portions. Gazo
Each of the two is provided on each of the injection molded resin substrates.
Between the wall of the book, the light emitting element and the photoelectric conversion element are
An injection molding tree in which the photoelectric conversion elements are respectively arranged
Between the outer wall of the oil substrate and at least one wall portion, the M
An OS-FET is arranged, and a plating pattern is provided between the photoelectric conversion element and the MOS-FET.
And a photoelectric conversion element provided with the plating pattern.
And the MOS-FET are wire-bonded, respectively.
In the MOS-FET , inclined reflection surfaces for efficiently transmitting the reflected light from the side surface of the light emitting element to the photoelectric conversion element are formed on the facing surfaces of the walls located on both sides of the light emitting element. Output optocoupler. 2. Each of the injection-molded resin substrates , on which the photoelectric conversion element is arranged , located on both sides of the photoelectric conversion element.
Reflected light from the side surface of the light emitting element is also applied to the facing surface of the wall portion.
Each slanted reflective surface that efficiently transmits to the photoelectric conversion element
The MOS-FET output optical coupling element according to claim 1, which is formed by the above method. 3. The injection molding resin substrate, wherein the inclined reflecting surface is plated with a material having high reflection efficiency.
Alternatively, the MOS-FET output optical coupling device according to claim 2. 4. The structure in which the front end surfaces of the wall portions formed on both of the injection molded resin substrates are in close contact with each other when the both injection molded resin substrates are bonded to each other .
4. The MOS-FET output optical coupling element according to any one of 3 above. 5. The MOS-FET output optical coupling device according to claim 1, wherein the MOS-FETs are arranged on both sides of the photoelectric conversion device. 6. The MOS-FE according to claim 1.
A method of manufacturing a T-output optical coupling element, comprising: die-bonding a light-emitting element to the facing surface of one injection-molded resin substrate, and die-bonding a photoelectric conversion element and a MOS-FET to the facing surface of the other injection-molded resin substrate. The process of wire-bonding these elements, the process of bonding both injection-molded resin substrates through the translucent resin, the process of dividing the bonded substrates into chips, and the subsequent inspection such as dielectric strength test. A method of manufacturing a MOS-FET output optical coupling device, including the step of performing.