JP2003282936A - Optical coupled element, method of manufacturing the same, and electronic equipment using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve miniaturization, readily bend a lead in the inner region of a package, and prevent the shape of a lead frame from being complicated. <P>SOLUTION: A pitch P of a lead 14c and a lead 14d is changed on a part of a primary tie bar 21 so as to be narrower on a light-receiving element 12 than the part of the primary tie bar 21. Therefore, in the inner region of the package 19, the pitch P of the leads 14c and 14d is reduced and a margin width W1 between the outer edge of the lead 14c and the outer edge of a package 19 is increased. Alternatively, even when the package 19 is made smaller as indicated by a chain line, the margin width W1 can be secured sufficiently. Thus, the absence of a filling synthetic resin, a void, or a crack of the package 19 does not occur on the part of the margin width W1. Further, the shape of the lead frame 14 is not complicated and thus the lead frame 14 can be worked with ease. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical coupling element that insulates between input and output to transmit a signal, a method for manufacturing the same, and an electronic apparatus to which the same is applied.

[0002]

As is well known, in this type of optical coupling element,
The light emitting element and the light receiving element are arranged so as to face each other, the electric signal is converted into an optical signal by the light emitting element, the optical signal is transmitted from the light emitting element to the light receiving element, and the optical signal is converted into an electric signal by the light receiving element. In this way, the input side and the output side are electrically insulated and signal transmission is performed.

FIG. 9 (a) shows a lead frame in a conventional optical coupling element. This lead frame 10
Reference numeral 1 is for supporting and connecting the light receiving element 102. The light receiving element 102 is mounted on the header 103a, and the light receiving element 102 and the bonding portion 103b are connected by a bonding wire. Similarly, the light emitting element is also mounted on the header of the lead frame and connected to the leads (not shown). Then, each lead frame on which the light receiving element and the light emitting element are mounted is positioned, and a synthetic resin that seals the light receiving element, the light emitting element and a part of each lead frame is molded to form the package 105, and further, The tie bar of each lead frame is cut to complete the optical coupling element.

The lead frame 101 is provided with two tie bars 106a and 106b, and the tie bars 106a and 106b respectively connect the leads 104a and 104b.
Are connected. In order to facilitate the processing of the lead frame, each lead 104a, 104b and each tie bar 10
6a and 106b are linearly formed. Further, the tie bars 106a and 106b are connected to the leads 104a and 104b, respectively.
Not only is b connected, it also serves to prevent the outflow of synthetic resin when the package 105 is molded. Two tie bars 106a and 106b are provided because molding is performed twice for double sealing.

Here, the lead 104 on the side of the light receiving element 102
The outer edge 104c of a and the outer edge 105 of the package 105
When the space a is set to the allowance width W, it is necessary to make the allowance width W sufficiently wide in order to prevent unfilling of the synthetic resin, voids, or cracking of the package 105 at the allowance width W.

On the other hand, with the recent miniaturization of electronic equipment, miniaturization of electronic parts is required, and the same applies to optical coupling elements. However, the lead pitch is standardized in the wiring pattern on the substrate of the electronic device, and the pitches of 2.54 mm and 1.27 mm are generally adopted. Therefore, even if the optical coupling element is downsized, the lead pitch of the lead frame cannot be easily changed. Therefore, in order to miniaturize the optical coupling element, it is only possible to miniaturize the package 105 without narrowing the pitch P of the leads 104a and 104b.

However, if the small package 105A is adopted as shown in FIG. 9B, the margin width W becomes narrower. Therefore, at the margin width W portion, there is no filling of synthetic resin or voids, or cracks in the package 105A. There has occurred.

Therefore, instead of the lead 104a shown in FIGS. 9 (a) and 9 (b), a lead 107 having a detour as shown in FIG. 9 (c) is employed, and the outer edge 10 of the lead 107 is adopted.
7A and the margin W between the outer edge 105a of the package 105A is widened.

[0009]

However, as shown in FIG.
Even if the lead 107 that is bent as shown in (c) is adopted, since the bent portion of the lead 107 is in the inner region of the package 105A, between the other outer edge 107b of the lead 107 and the outer edge 105a of the package 105A. The allowance width W ′ is narrow, and unfilled with synthetic resin, voids, or cracks in the package 105 </ b> A occurred at the part of the allowance width W ′.

Further, in general, in order to appropriately set the distance between the light emitting element and the light receiving element, it is necessary to bend each lead supporting the light emitting element and the light receiving element in the inner region of the package. However, in the case of the lead 107, since the lead 107 has a bent portion, it is difficult to bend the lead 107. If the lead 107 is bent near the bent portion, the lead 1 is bent.
A complicated stress acts on 07, the processing accuracy of the lead 107 is deteriorated, and the characteristics of the optical coupling element become unstable.

On the other hand, Japanese Unexamined Patent Publication No. 10-326856 discloses a semiconductor device in which leads are bent outside the tie bar. However, because the lead is detoured outside the tie bar and the lead pitch is set,
The leads became too long, and it could not be said that the semiconductor device as a whole was downsized.

Further, even if the lead is bent in the inner region of the package or the lead is bent outside the tie bar, the shape of the lead frame is still complicated, which makes it difficult to process the lead frame. And the cost has risen.

Therefore, the present invention has been made in view of the above-mentioned problems of the prior art, and it is possible to achieve miniaturization, easy bending of the lead in the inner region of the package, and the shape of the lead frame. The present invention relates to an optical coupling element that does not cause complication, a manufacturing method thereof, and an electronic device to which the optical coupling element is applied.

[0014]

In order to solve the above problems, the present invention mounts a light emitting element and a light receiving element on a lead frame, and seals a part of the light emitting element, the light receiving element and the lead frame with a sealing resin. In the sealed optical coupling element, the lead frame on the side of the light receiving element has a plurality of leads and a tie bar that connects the leads. The pitch of each lead is changed at the tie bar portion, and the pitch is adjusted by the tie bar. It is narrower on the side of the light receiving element than on the part.

According to the optical coupling element of the present invention having such a configuration, the pitch of each lead is changed at the portion of the tie bar and is made narrower at the light receiving element side than the portion of the tie bar. Therefore, in the inner region of the package, the pitch of each lead is narrowed, and it is possible to reduce the size of the package while ensuring a margin between the outer edge of the lead and the outer edge of the package. Further, in the inner region of the package, it is not necessary to detour the lead, and the lead can be easily bent. Furthermore, since the pitch of each lead is changed at the tie bar, compared to the conventional one in which the pitch is changed outside the tie bar, each lead can be shortened, which facilitates downsizing of the entire optical coupling element. Become. Further, the shape of the lead frame does not become complicated, the lead frame can be easily processed, and the increase in cost can be suppressed.

In the present invention, the primary tie bar,
Also, a secondary tie bar that is farther from the light receiving element than the primary tie bar is provided, and the pitch of each lead is changed at any part of the primary tie bar and the secondary tie bar so that the pitch becomes narrower on the light receiving element side. is doing. Alternatively, a primary tie bar and a secondary tie bar farther from the light receiving element than the primary tie bar are provided, and the pitch of each lead is changed stepwise at the secondary tie bar part and the primary tie bar part,
The pitch is narrower on the primary tie bar side than on the secondary tie bar portion, and is further narrower on the light receiving element side than the primary tie bar.

When two tie bars are provided in this way, the pitch of each lead may be narrowed by changing the position of either the primary tie bar or the secondary tie bar, or the pitch of each lead. May be gradually changed to be narrower at the secondary tie bar portion and the primary tie bar portion.

Further, in the present invention, the lead is orthogonal to the tie bar.

By making the leads orthogonal to the tie bars in this way, the shape of the lead frame is most simplified, and the processing accuracy can be improved by pressing the tie bars when bending the leads.

Further, in the present invention, the lead frame on the light emitting element side has a plurality of leads and a tie bar for connecting the respective leads, and the pitch of each lead is changed at the tie bar portion to obtain the pitch. Is narrower on the light emitting element side than the tie bar portion.

Thus, the lead frame on the light emitting element side can also achieve the same effect as the lead frame on the light receiving element side, and the degree of freedom in designing the optical coupling element is increased.

Next, the manufacturing method of the optical coupling element of the present invention is as follows.
The method includes mounting the light emitting element and the light receiving element on a lead frame, sealing the light emitting element, the light receiving element, and a part of the lead frame with a sealing resin, and cutting the tie bar of the lead frame. There is.

The optical coupling element of the present invention can be manufactured by such a manufacturing method.

The electronic equipment of the present invention includes the optical coupling element of the present invention.

That is, the present invention is not limited to the optical coupling element and the manufacturing method thereof, but includes electronic equipment to which the optical coupling element is applied. This electronic device is DV
A reproducing device such as D, VTR, STB, CD, MD, etc., an image receiving device, a power supply, an inverter, etc., and any kind of device as long as it includes a circuit which insulates between input and output and transmits a signal. I don't mind.

[0026]

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

FIGS. 1A and 1B are sectional views showing a first embodiment of an optical coupling element of the present invention as viewed from the front and side. In the optical coupling element of the present embodiment, the light emitting element 11 and the light receiving element 12 are connected to the lead frame 1 respectively.
The light emitting element 11 is mounted on the headers 13a and 14a of the wirings 3 and 14 to connect the light emitting element 11 to the bonding portion (not shown) of the lead frame 13 via the wire 15, and the light receiving element 12 to the bonding portion 14b via the wire 16. And the light-emitting element 11 and the light-receiving element 12 are arranged to face each other by positioning the lead frames 13 and 14, and the light-transmitting resin 1 becomes an optical path between the light-emitting element 11 and the light-receiving element 12.
7 is formed by primary molding, a light-shielding resin 18 that prevents the entry of ambient light and light leakage from the inside is formed by secondary molding, and a package 19 including the light-transmitting resin 17 and the light-shielding resin 18 is used. The light emitting element 11 and the light receiving element 12 are sealed.

In this optical coupling element, the light transmission path from the light emitting element 11 to the light receiving element 12 is set linearly,
As shown in FIG. 2, an electric signal is converted into an optical signal by the light emitting element 11, and this optical signal is transferred from the light emitting element 11 to the light receiving element 12.
The light receiving element 12 converts the optical signal into an electric signal, whereby the input side and the output side are electrically insulated, and the signal is transmitted.

FIG. 3 is a plan view showing an outer lead frame in which a plurality of lead frames 14 each mounting the light receiving element 12 are connected in a comb tooth shape. Here, the two leads 14c and 14d of the plurality of lead frames 14 are
The next tie bar 21, the second tie bar 22, and the outer frame portion 23 are connected to each other. Similarly, the two leads of each lead frame 13 on which the respective light emitting elements 11 are mounted are connected in a comb-teeth shape by a primary tie bar, a secondary tie bar, and an outer frame portion (not shown).

On the side of the light receiving element 12, the leads 14c and 14d of the lead frames 14 connected to each other are connected to each other as shown in FIG.
Each lead 14 is bent as shown in FIG.
Each light receiving element 12 is adhered to the header 14a at the tip of c by die bonding, and the bonding portion 14b at the tip of each lead 14d and each light receiving element 12 are connected via each wire 16 formed by wire bonding. Similarly, also on the light emitting element 11 side, each lead of each lead frame 13 is bent, each light emitting element 11 is bonded to each header 13a by die bonding, and each bonding portion and each light emitting element 11 are wire bonded. Each wire 15 formed by
Connect through.

Then, each lead frame 13 and each lead frame 14 are positioned, and each light emitting element 11 and each light receiving element 12 are arranged facing each other for each optical coupling element, and a transparent resin is provided for each optical coupling element. 17 is formed by primary molding, a light blocking resin 18 is formed by secondary molding, and the package 19 seals the light emitting element 11 and the light receiving element 12. During the primary molding and the secondary molding, the translucent resin 17 and the light-shielding resin 18 are prevented from flowing out by the primary tie bar and the secondary tie bar of each lead frame 13 and each lead frame 14.

After that, the primary tie bar and the secondary tie bar of each lead frame 13 and each lead frame 14 are cut to separate each optical coupling element.

The outer lead frame is not limited to one in which each lead frame is connected in the shape of a comb, but is also one in which each lead frame is connected in the shape of a ladder as shown in FIG. Also in the outer lead frame of FIG. 4, a plurality of lead frames 14 are attached to the primary tie bars 21, 2
It is connected by the next tie bar 22 and the outer frame portion 23.

Since the light receiving element 12 needs to have a large light receiving surface, its chip size is larger than that of the light emitting element 11. Therefore, the size of the header of the lead frame is larger in the light receiving element 12 than in the light emitting element 11. Therefore, in order to reduce the size of the package 19, first, the size of the lead frame on the light receiving element 12 side needs to be reduced in the inner region of the package 19.

FIG. 5A is a plan view showing the lead frame 14 and the package 19 on the side of the light receiving element 12, and FIG. 5B is a sectional view of the primary tie bar 21 and the secondary tie bar 22 of the lead frame 14. It is a top view showing the state where it did. In addition, in FIG. 5A and FIG.
The lead frame 13 on the first side is omitted.

As is apparent from FIGS. 5A and 5B, the pitch P of the leads 14c and 14d of the lead frame 14 is
Is changed in the part of the primary tie bar 21 and is narrower on the light receiving element 12 side than the part of the primary tie bar 21.
Therefore, in the inner region of the package 19, each lead 14
The pitch P of c and 14d becomes narrower, and the margin width W1 between the outer edge of the lead 14c and the outer edge of the package 19 becomes wider. Alternatively, even if the package 19 is downsized as shown by the one-dot chain line, the margin width W1 can be sufficiently secured. Therefore, it is possible to prevent unfilling of synthetic resin, voids, or cracking of the package 19 at the margin width W1. Further, since the pitch P of each lead 14c, 14d is changed at the portion of the primary tie bar 21, as compared with the conventional one in which the pitch is changed outside the tie bar,
Since the leads 14c and 14d are short, it is easy to downsize the entire optical coupling element. Further, the shape of the lead frame 14 does not become complicated, the lead frame 14 can be easily processed, and an increase in cost can be suppressed.

A die is used for bending each lead. Therefore, when the lead 107 is bent in the vicinity of the detoured portion as in the conventional case shown in FIG. 9C, a complicated stress acts on the lead 107, and the processing accuracy of the lead 107 deteriorates. On the other hand, in this embodiment, the primary tie bars 21 and 2 orthogonal to the leads 14c and 14d are provided.
Since the next tie bar 22 is pressed by the mold and the linear portions of the leads 14c and 14d in the inner region of the package 19 are bent, the processing accuracy is increased and the characteristics of the optical coupling element can be stabilized. it can.

In addition, moisture, plating liquid, etc., are contained in the package 19
When the light penetrates from the outside to the inside of the
In addition, since it adversely affects the light receiving element 12, it is necessary to suppress the infiltration of these. To this end, if the lead 107 is bent as in the conventional case shown in FIG. 9C, the penetration path of the water, the plating solution, etc., which is indicated by the arrow A, becomes long, and the penetration of these can be prevented. However, as described above, since the vicinity of the detoured portion of the lead 107 is bent, it is inevitable that the processing accuracy of the lead 107 deteriorates. On the other hand, in the present embodiment, after the primary tie bar 21 and the secondary tie bar 22 of the lead frame 14 are cut, the leads 14c and 14d are clearly detoured, and the arrow A of water, plating solution, etc. The intrusion route indicated by is long. Moreover, each lead 14
The c and 14d can be bent with high precision.
Further, in the present embodiment, the lead 19 is formed by the package 19 instead of forming the detour portion of the lead 107 at the time of manufacturing the lead frame as in the conventional case shown in FIG. 9C.
By cutting the primary tie bar 21 and the secondary tie bar 22 while pressing the c and 14d, the detoured portions of the leads 14c and 14d are formed, so that the machining accuracy of the detoured portions is increased.

Further, the lead frame 1 on the light receiving element 12 side
In addition to the pitch P of the leads 14c and 14d of No. 4,
The pitch of the leads of the lead frame 13 on the light emitting element 11 side may be narrowed at the primary tie bar portion.

Here, by inclining each wall 19a of the package 19 as shown in FIGS. 1 (a) and 1 (b),
The incidence rate of light on the light receiving surface of the light receiving element 12 is increased. Therefore, the space between the inner walls 19a is widest in the vicinity of the center of the package 19. On the other hand, the input current of the light emitting element 11 is IF
And the output current of the light receiving element 12 is IC, the current transfer ratio CTR = IC / IF, and the current transfer ratio CT
R is important as a characteristic of the optical coupling element. If the light emitting element 11 and the light receiving element 12 have already been used, it is preferable not to change the existing distance between the light emitting element 11 and the light receiving element 12 in order to maintain the current transfer ratio CTR, and the device design is easy. Is. Therefore, the positions of the light emitting element 11 and the light receiving element 12 cannot be easily changed.

Regarding the light receiving element 12, since the pitch P of the leads 14c and 14d of the lead frame 14 is narrowed from the portion of the primary tie bar 21, the light receiving element 12 is located near the center of the package 19 where the distance between the inner walls 19a is wide. Even if the element 12 is not moved, a sufficient margin width W1 between the outer edge of the lead 14c and the outer edge of the package 19 can be secured. That is, the degree of freedom in setting the position of the light receiving element 12 is high. Similarly, with respect to the light emitting element 11, if the pitch of the leads of the lead frame 13 is narrowed from the primary tie bar portion, the light emitting element 11 does not have to be moved toward the center of the package 19 as shown in FIG. It is possible to secure a sufficient margin W2 between the outer edge of the lead and the outer edge of the package 19. That is, the degree of freedom in setting the position of the light emitting element 11 can be increased. Therefore, the current transfer ratio CT
Even if the positions of the light emitting element 11 and the light receiving element 12 are set by giving priority to R, the margin widths W1 and W2 do not become narrow.

Further, as shown in FIG. 7, the pitch P between the leads 14c and 14d of the lead frame 14 on the light receiving element 12 side.
Is changed by the secondary tie bar 22, and each lead 14c, 14 is changed.
The pitch P of d may be narrowed on the light receiving element 12 side. Alternatively, as shown in FIG. 8, the pitch P of each lead 14c, 14d of the lead frame 14 on the side of the light receiving element 12 is changed in each part of the primary tie bar 21 and the secondary tie bar 22, and each lead 14c, 14d is changed. The pitch P may be narrowed stepwise. In this case, the invasion path of water, plating solution, or the like, which is indicated by the arrow A, is detoured in a complicated manner, so that infiltration of these can be effectively prevented.

Further, the lead frame 1 on the light emitting element 11 side
With respect to No. 3, the pitch of each lead may be narrowed at the secondary tie bar portion, or may be gradually narrowed at each of the primary tie bar and secondary tie bar portions.

The present invention is not limited to the above embodiment and can be modified in various ways. For example,
It is also possible to make only one of the leads of the lead frame detour at the tie bar portion to narrow the pitch of the leads. Further, the present invention is not limited to the optical coupling element and the manufacturing method thereof, and includes electronic equipment to which the optical coupling element is applied. This electronic device is a DVD, VTR, S
Any kind of reproducing device such as TB, CD, MD, an image receiving device, a power source, an inverter, etc. may be used as long as it includes a circuit that insulates between input and output and transmits a signal.

[0045]

As described above, according to the present invention, the pitch of each lead is changed at the tie bar portion and narrower at the light receiving element side than at the tie bar portion. Therefore,
In the inner region of the package, the pitch of each lead is narrowed, and it is possible to reduce the size of the package while ensuring a margin between the outer edge of the lead and the outer edge of the package.
Further, in the inner region of the package, it is not necessary to detour the lead, and the lead can be easily bent. Furthermore, since the pitch of each lead is changed at the tie bar, compared to the conventional one in which the pitch is changed outside the tie bar, each lead can be shortened, which facilitates downsizing of the entire optical coupling element. Become. Further, the shape of the lead frame does not become complicated, the lead frame can be easily processed, and the increase in cost can be suppressed.

Further, according to the present invention, when two tie bars are provided, the pitch of each lead can be changed by making it narrower at any part of the primary tie bar and the secondary tie bar, or by changing the pitch of each lead. The pitch is gradually changed and narrowed at the secondary tie bar part and the primary tie bar part.

Further, according to the present invention, since the lead is orthogonal to the tie bar, the shape of the lead frame is most simplified, and when the lead is bent, the tie bar is pressed to improve the working accuracy. be able to.

Further, according to the present invention, the lead frame on the light emitting element side is also made narrower by changing the pitch of each lead at the portion of the tie bar, so that the same effect as the lead frame on the light receiving element side is achieved. Therefore, the degree of freedom in designing the optical coupling element is increased.

[Brief description of drawings]

1A and 1B are cross-sectional views showing a first embodiment of an optical coupling element of the present invention as viewed from the front and side surfaces.

FIG. 2 is a circuit diagram showing the optical coupling element of FIG.

FIG. 3 is a plan view showing an outer lead frame in which a plurality of lead frames each mounting the light receiving element of FIG. 1 are connected in a comb tooth shape.

FIG. 4 is a plan view showing an outer lead frame in which a plurality of lead frames each mounting the light receiving element of FIG. 1 are connected in a ladder shape.

5A is a plan view showing a lead frame and a package on the light receiving element side of FIG. 1, and FIG. 5B is a plan view showing a state where a tie bar of the lead frame is cut.

FIG. 6 is a cross-sectional view showing a modified example of the optical coupling element of FIG. 1 when viewed from the side.

7 is a plan view showing a modified example of the lead frame on the light receiving element side of FIG. 1. FIG.

8 is a plan view showing another modified example of the lead frame on the light receiving element side of FIG. 1. FIG.

9A, 9B, and 9C are plan views showing examples of a conventional optical coupling element.

[Explanation of symbols]

11 Light emitting element 12 Light receiving element 13,14 Lead frame 13a, 14a header 14b Bonding part 14c, 14d lead 15,16 wire 17 Translucent resin 18 Light-shielding resin 19 packages 21 Primary Tie Bar 22 Second tie bar 23 Outer frame

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Claims (7)

[Claims] 1. An optical coupling element in which a light emitting element and a light receiving element are mounted on a lead frame, and the light emitting element, the light receiving element, and a part of the lead frame are sealed with a sealing resin, wherein the lead frame on the side of the light receiving element is , A plurality of leads, and a tie bar connecting the leads, wherein the pitch of each lead is changed at the tie bar portion and the pitch is made narrower on the light receiving element side than at the tie bar portion. Optical coupling element. 2. A primary tie bar and a secondary tie bar farther from the light receiving element than the primary tie bar are provided, and the pitch of each lead is changed at any part of the primary tie bar and the secondary tie bar. The optical coupling element according to claim 1, wherein the pitch is narrowed on the light receiving element side. 3. A primary tie bar and a secondary tie bar that is farther from the light receiving element than the primary tie bar are provided, and the pitch of each lead is changed stepwise at the secondary tie bar part and the primary tie bar part. 2. The optical coupling element according to claim 1, wherein the pitch is narrower on the primary tie bar side than on the secondary tie bar portion, and the pitch is further narrower on the light receiving element side than the primary tie bar. . 4. The optical coupling element according to claim 1, wherein the lead is orthogonal to the tie bar. 5. The light emitting element side lead frame has a plurality of leads and a tie bar that connects the leads, and the pitch of each lead is changed at the tie bar portion so that the pitch is greater than the tie bar portion. 5. The optical coupling element according to claim 1, wherein the light-emitting element side is also narrowed. 6. The method for manufacturing an optical coupling element according to claim 1, wherein the light emitting element and the light receiving element are mounted on a lead frame, the light emitting element, the light receiving element, and a part of the lead frame. And a step of cutting the tie bar of the lead frame. A method of manufacturing an optical coupling element, comprising: 7. An electronic device comprising the optical coupling element according to claim 1. Description: