JPH06132561A - Lead frame for optical coupler - Google Patents

Abstract

PURPOSE:To perform a complete finish plating by one operation and eliminate a welding process of a light emitting side lead frame and a light receiving side lead frame. CONSTITUTION:A light emitting side lead frame 100 and a light receiving side lead frame 200 are provided. Both the lead frames 100 and 200 comprise a pair of cradle parts 110a, 110b and 210a, 210b, a plurality of lead parts 120 and 220 formed between the cradle parts in parallel with the cradle parts, and header parts 130 and 230 formed on the tops of the lead parts 120 and 130. Further, when the header parts 130 and 230 of the lead frames 100 and 200 are oppositely combined, the cradle parts 110a, 110b and 210a, 210b of the lead frames 100 and 200 overlap, and a protrusion 150 formed on the cradle parts 110a and 110b of the light emitting side lead frame 100 fits into an opening 250 formed in the cradle parts 210a and 210b of the light receiving side lead frame 200.

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 lead frame, and more particularly to a transfer mold type photo coupler lead frame.

[0002]

2. Description of the Related Art Generally, photocouplers are roughly classified into a single transfer mold type (docking type) and a double transfer mold type. These transfer mold type photocouplers have a light emitting element and a light receiving element, respectively. After die bonding and wire bonding to individual lead frames, the light emitting element and the light receiving element are combined so as to face each other by spot welding, and a molded body is formed in a molding die. After that, the lead frame portion led out of the mold body is subjected to exterior plating with solder or tin, and the photo coupler is completed through the steps of lead cutting and forming.

This conventional example will be described with reference to FIGS. 12 and 13. FIG. 12 is a plan view of a light emitting side lead frame 500 and a light receiving side lead frame 600 which constitute a conventional optical coupling element lead frame, and FIG. 13 shows a state where a secondary molding body is formed on the optical coupling element lead frame. It is a top view.

The header portion 53 of the light emitting side lead frame 500
Die-bond and wire-bond the light-emitting element to 0 and the light-receiving element to the header section 630 of the lead frame 600 on the light-receiving side, and then perform spot welding with the welded sections 540 and 640 of both lead frames 500 and 600 overlapped. Connect both leadframes 500 and 600. Thereafter, a primary mold body (not shown) that covers the header portions 530 and 630 is formed in a molding die (not shown). Furthermore, from the top of the primary mold body, a secondary mold body 700 as shown in FIG.
To form. Lead part extended from the secondary mold body 700
The 520 and 620 are plated with an exterior by solder or tin. Since this exterior plating is usually performed by an electrolytic plating method, as shown in FIG. 13, one in which both lead frames 500 and 600 are joined by a cathode electrode K (hereinafter, referred to as
"Lead frame combination". ) Is manually sandwiched and held.

[0005]

However, the above-mentioned conventional lead frame for an optical coupling element has the following problems. That is, the exterior plating process is being automated in order to increase the processing capacity, shorten the turn, and reduce the cost. For this reason, automation cannot be achieved by a method in which the lead frame assembly is manually sandwiched between the cathode electrodes. Therefore, a method of hooking a J-shaped hook-shaped cathode electrode on one of the saw holes 511 and 611 formed in the cradle portion of one of the lead frames 500 and 600, and a method of cathode electrode The method of putting the lead frame assembly one by one in a basket made of is becoming mainstream.

However, in both methods, the light emitting side lead frame is used.
Exterior plating is performed in a state where the cathode electrode K is in contact with only one of the 500 and the light-receiving side lead frame 600. At this time, both lead frames 500 and 600 are welded to
, 640 is also electrically connected, so there seems to be no problem, but in reality, the welds 540 and 640 are stressed by pressure and heat during molding (both leadframes).
Often due to stress due to the difference in expansion coefficient between 500 and 600 and the mold resin), as a result, plating may be applied only to the lead frame which is in contact with the cathode electrode K. For this reason, re-plating is required, which causes a reduction in the number of processes, an increase in turn, and a cost increase.

The present invention was devised in view of the above circumstances, and is an optical coupling that can perform a complete exterior plating in a single operation and that does not require a welding process of a light emitting side lead frame and a light receiving side lead frame. It is intended to provide a lead frame for a device.

[0008]

A lead frame for an optical coupling element according to a first aspect of the present invention comprises a light emitting side lead frame and a light receiving side lead frame, both lead frames having a pair of cradle portions and the cradle portion. It has a plurality of lead parts formed in parallel with the cradle part and a header part formed at the tip of this lead part, and when combined so that the header parts of both lead frames face each other. , The cradle parts of both lead frames overlap.

A lead frame for an optical coupling element according to a second aspect comprises a light emitting side lead frame and a light receiving side lead frame, and the cradle portions of the both lead frames are aligned when the cradle portions are overlapped. An aperture is provided.

A lead frame for an optical coupling element according to a third aspect of the present invention includes a light emitting side lead frame and a light receiving side lead frame, and when the both lead frames are combined, a protruding portion electrically connecting the both lead frames is formed. It is provided on at least one of the lead frames.

A lead frame for an optical coupling element according to a fourth aspect of the present invention comprises a light emitting side lead frame and a light receiving side lead frame, and one of the lead frames has a protrusion on the cradle and the other lead frame. An opening is provided in each of the cradle parts, and when the lead frames are combined, the projection is fitted in the opening.

A lead frame for an optical coupling element according to a fifth aspect includes a light emitting side lead frame and a light receiving side lead frame, and one of the lead frames has a protrusion on the cradle and the other lead frame. The cradle portion is provided with an opening, respectively, and when both lead frames are combined, the projection is fitted into the opening, and the portion where both are fitted is covered with a resin mold.

[0013]

FIG. 1 is a plan view and a side view of a light emitting side lead frame and a light receiving side lead frame constituting a lead frame for an optical coupling element according to an embodiment of the present invention, and FIG. 2 is a header portion of both lead frames. Is a plan view and a side view, and FIG. 3 is a plan view and a side view showing a state in which a light emitting side lead frame and a light receiving side lead frame are combined and subjected to a primary molding.
FIG. 4 is a plan view and a side view showing a state in which a light emitting side lead frame and a light receiving side lead frame are combined and subjected to a secondary molding, and FIG. 5 is a projection formed by combining the light emitting side lead frame and the light receiving side lead frame. FIG. 6 is a cross-sectional view taken along the line AA of FIG. 3, FIG. 6 is an explanatory view when the lead frame for an optical coupling element is subjected to exterior plating, and FIG. FIG. 8 is a schematic sectional view of an optical coupling element using an element lead frame, and FIG. 8 is a sectional view showing another embodiment of the optical coupling element lead frame according to the present invention.

FIG. 9 is a cross-sectional view for explaining a case where a resin mold is used to cover a portion where the projection and the opening are fitted by combining the light emitting side lead frame and the light receiving side lead frame, and FIG. 11 is a plan view and a side view of the side lead frame and the light receiving side lead frame, and FIG. 11 is a plan view and a side view of a state in which the light emitting side lead frame and the light receiving side lead frame are combined and primary molding is performed.

The lead frame for an optical coupling element according to this embodiment comprises a light emitting side lead frame 100 and a light receiving side lead frame 200.

The light emitting side lead frame 100 includes a pair of cradle parts 110a and 110b, a plurality of lead parts 120 formed between the cradle parts 110a and 110b in parallel with the cradle parts 110a and 110b, and the lead parts 120. And a header portion 130 formed at the tip of the. The cradle section 110
Protrusions 150 are provided on a and 110b.

The pair of cradle portions 110a and 110b of the light emitting side lead frame 100 are formed in parallel with each other, and openings 111a and 111b are formed at predetermined intervals. Also,
Both of the cradle 110a, 110b are a slightly thicker base end side tie bar 140, and a slightly thinner primary tie bar 141 and secondary tie bar provided in parallel to the base end side tie bar 140.
142 and are connected by.

From the proximal tie bar 140 to the primary tie bar 141
A plurality of sets (5 sets in the drawing) of lead portions 120 are formed over the entire length. At the tip of the lead portion, a header portion 130 to which a light emitting element 410 such as a light emitting diode is bonded
Are formed. This header section 130 is shown in FIG.
, The light emitting element 410 is die-bonded to the cup portion 131, the light emitting element 410, and the bonding wire 41.
It is composed of a wire connecting portion 132 connected by 1. The header portion 130 is bent so as to be recessed toward the back side of the paper in the plan view of FIG. 2 (A). The shape of the header portion 130 shown in the figure is an example, and it goes without saying that it can be appropriately changed.

Cradle part of the lead frame 100 on the light emitting side
The protrusions 150 provided on the 110a and 110b project to the side of the light-receiving side lead frame 200 that is in close contact with the cradle 210a and 210b. Further, a positioning notch 160 is provided inside the cradle portions 110a and 110b. This positioning notch 160 is a combination of
The 0 tie bars 240, 241, 242 are designed to fit.

On the other hand, the light-receiving side lead frame 200 has substantially the same main parts as the light-emitting side lead frame 100,
The three tie bars 240, 241, 242 are cradle parts 210a,
It is different in that it is bent to the front side of the paper at the boundary with 210b. This is a tie bar on the positioning notch 160.
This is so that the 240, 241, and 242 fit together.
The header section 230 is composed of a cup section 231 to which the light receiving element 420 is die-bonded and a wire connecting section 232 which is connected to the light receiving element 420 by a bonding wire 421. Of course, the shape can be changed. The header portion 230 is bent so as to be recessed toward the back side of the paper in the plan view of FIG. 2 (B).

The cradle portions 210a and 210b of the light receiving side lead frame 200 are provided with openings 250 corresponding to the protrusions 150 of the light emitting side lead frame 100. That is, when the two lead frames 100, 200 are combined, the protrusion 150 is fitted in the opening 250. The cradle portions 210a and 210b of the light-receiving side lead frame 200 are formed to have the same width as the cradle portions 110a and 110b of the light-emitting side lead frame 100 or to be slightly narrower.

Next, such a light emitting side lead frame 10
A manufacturing process of an optical coupling element using the optical coupling element lead frame constituted by 0 and the light receiving side lead frame 200 will be described.

First, the light emitting element 410 and the light receiving element 420 are die-bonded and wire-bonded to the header portions 130 and 230 of the lead frames 100 and 200, respectively.
A precoat resin 412 such as a silicone resin is applied to the light emitting element 410 for protection.

Next, the lead frames 100 and 200 are combined so that the elements 410 and 420 face each other to form a lead frame assembly. In this state, both lead frames 100
, 200 holes 111a, 111b, 211a, 211b are aligned with each other, and the tie bar 24 of the receiving side lead frame 200 is
0, etc. are for the notch 16 for positioning the lead frame 100 on the light emitting side.
Fits in 0. At the same time, the projection 150 of the light emitting side lead frame 100 faces the opening 250 of the light receiving side lead frame 200 (see FIG. 5A).

Next, a primary molding die 45 for forming a primary molding body 310 on both the lead frames 100, 200.
Perform 0 mold clamping. Then, the protrusion 150 fits into the opening 250 (see FIG. 5B). As a result, both lead frames 100 and 200 are electrically connected.
After forming the primary mold body 310 (see FIG. 3), the mold 450 for the primary mold is opened, and the thick burrs of the primary mold body 310 are removed and the primary tie bars 141 and 241 are cut. . At this time, since the protrusion 150 is fitted into the opening 250, the protrusion 150 does not come off the opening 250 even when the mold 450 for the primary molding is opened (see FIG. )).

Further, a mold for secondary molding (not shown)
Thus, a secondary mold body 320 as shown in FIG. 4 is formed. The secondary mold body 320 is not blocked by the secondary tie bars 142 and 242 and does not go around to other parts. After this, after-curing is performed on the secondary mold body 320.

Exterior plating is applied to the lead frame assembly formed as described above.
As shown in (A) and (C), the hook-shaped cathode electrode K is hooked on the openings 111a (111b) and 211a (211b), and as shown in FIGS. This is performed by placing the lead frame assembly on the basket-shaped cathode electrode K. Since both the lead frames 100 and 200 that form the lead frame assembly are electrically connected to each other by the protrusion 150 and the opening 250, the outer plating can be reliably applied to both the lead frames 100 and 200.

After the exterior plating is completed, the secondary tie bars 142 and 242 are cut and the lead portions 120 and 220 are lead-formed to complete the optical coupling element.

In the above-described embodiment, the double transfer mold type surface-mount type optical coupling element is taken as an example. However, the present invention is not limited to this, and the single transfer mold type optical coupling element is used. It can also be applied to a device, a DIP type or a single tie bar type.
Further, it is possible to form an opening in the light emitting side lead frame 100 and form a protrusion in the light receiving side lead frame 200, or to form an aperture and a protrusion in both lead frames 100, 200.

In the embodiment described above, both lead frames 10
Although the electrical connection of 0 and 200 is made by fitting the projection 150 and the opening 250, as shown in FIG. 8A, the projections are formed on the cradle parts 110a and 110b of the light emitting side lead frame 100. 15
It is not necessary to provide the openings 250 in the cradle portions 210a and 210b of the light-receiving side lead frame 200 only by providing 0. That is, when using the primary molding die 460 in which the upper mold 461 is provided with the gap 461a corresponding to the protrusion 150, the periphery of the protrusion 150 is crushed during mold clamping, and the cradle of the lead frame 200 on the light receiving side is crushed. The parts 210a and 210b are closely attached (Fig. 8).
(See (B) and (C)). In this way, both lead frames 1
It is also possible to secure 00, 200 electrical connections.

The protrusions 150 and the openings 25 are formed in the cradle portions 110a, 110b, 210a, 210b of the lead frames 100, 200.
Even if 0 is not provided, the cradle portions 110a, 110b, 210a, 210b of the lead frames 100, 200 are arranged to overlap each other, so that it is possible to secure the electrical connection between the lead frames 100, 200. .

Further, as shown in FIG. 9, the portion where the protrusion 150 and the opening 250 are fitted can be covered with the resin mold 311. This is because the fitting portion cavity 451 is formed in the primary molding die 450 for forming the primary molding body 310, and the fitting portion cavity 451 is formed.
A resin mold 311 is formed by injecting the same molding resin as that of the primary molding body 310 into the resin, and the lead frames 100 and 200 are firmly combined by the resin mold 311 (see FIG. 9B). ). Therefore, the formation of the primary mold body 310 and the resin mold 311 and the fitting of the protrusion 150 and the opening 250 are simultaneously performed.

As described above, the protrusion 150 is formed by the resin mold 311.
In the case of covering the fitted part of the hole 250 with the opening 250, it is desirable to differ from the one shown in FIGS. 1 to 8 in the following points. That is, the protrusions of the lead frames 100 and 200 shown in FIGS.
Although the 150 and the opening 250 are formed at positions deviated from the headers 130 and 230, it is desirable that they are formed on both sides of the headers 130 and 230 in FIGS. 9 to 11. Of.

Because the resin mold 311 must be formed at the same time when the primary mold body 310 is formed, the fitting portion cavity 451 is formed in the primary mold body 31.
This is because it is efficient that they are communicated with the same runner as the cavity forming 0 (not shown).

Further, of the cradle portions 110a and 110b of the light emitting side lead frame 100, both sides of the cradle portions 110a and 110b, on which the protrusions 150 are formed, are slightly thinner than the other portions, so that the light emitting side concave portion 17 is formed.
0 is formed. Similarly, the lead frame 20 on the receiving side
A light receiving side recess 270 is formed in a portion of the 0 cradle portion 210a, 210b where the opening 250 is formed and a portion corresponding to the light emitting side recess 170.

Since the portion where the protrusion 150 and the opening 250 are fitted together is covered with the resin mold 311, both lead frames 100 and 200 are electrically connected. Even when the mold 450 for the primary molding is opened, the fitting portion between the protrusion 150 and the opening 250 is covered with the resin mold 311 so that it is more difficult to come off (FIG. 9).
(See (C)).

[0037]

The lead frame for an optical coupling element according to the present invention comprises a light emitting side lead frame and a light receiving side lead frame, both lead frames having a pair of cradle parts and a cradle part between the cradle parts. And a plurality of lead portions formed in parallel with each other, and a header portion formed at the tips of the lead portions. When the header portions of both lead frames are combined so as to face each other, Since the cradle portions are overlapped with each other and the projection formed on the cradle portion and the opening are fitted to each other, electrical connection between both lead frames can be surely performed. For this reason, complete outer plating can be applied in one operation,
Moreover, it is possible to reduce the number of steps and to adapt to the recent automated exterior plating process.

When both lead frames are combined, if at least one lead frame is provided with a protrusion for electrically connecting both lead frames, both lead frames can be electrically connected even if there is no hole for fitting. A reliable connection is possible.

[Brief description of drawings]

1A and 1B are a plan view and a side view of a light emitting side lead frame and a light receiving side lead frame that form a lead frame for an optical coupling element according to an embodiment of the present invention.

FIG. 2 is a plan view and a side view of a header portion of both lead frames.

3A and 3B are a plan view and a side view showing a state in which a light emitting side lead frame and a light receiving side lead frame are combined and primary molding is performed.

4A and 4B are a plan view and a side view showing a state in which a light emitting side lead frame and a light receiving side lead frame are combined and a secondary molding is performed.

5 is a cross-sectional view taken along the line AA of FIG. 3 for explaining fitting of the protrusion and the opening by combining the light emitting side lead frame and the light receiving side lead frame.

FIG. 6 is an explanatory diagram in the case of applying exterior plating to the lead frame for the optical coupling element.

FIG. 7 is a schematic cross-sectional view of an optical coupling element using the lead frame for the optical coupling element.

FIG. 8 is a cross-sectional view showing another embodiment of the lead frame for an optical coupling element according to the present invention.

FIG. 9 is a cross-sectional view illustrating a case in which a resin mold covers a portion where a protrusion and an opening are fitted by combining a light emitting side lead frame and a light receiving side lead frame.

FIG. 10 is a plan view and a side view of the light emitting side lead frame and the light receiving side lead frame.

11A and 11B are a plan view and a side view showing a state in which the light emitting side lead frame and the light receiving side lead frame are combined and primary molding is performed.

FIG. 12 is a plan view of a light emitting side lead frame and a light receiving side lead frame forming a conventional lead frame for an optical coupling element of this type.

FIG. 13 is a plan view showing a state where a secondary mold body is formed by combining a conventional light emitting side lead frame and a conventional light receiving side lead frame.

[Explanation of symbols]

 100 Light emitting side lead frame 110a, 110b (light emitting side lead frame) cradle section 111a, 111b (light emitting side lead frame) Opening 120 (light emitting side lead frame) Lead section 130 (light emitting side lead frame) Header section 150 Projection 200 Receiving side lead frame 210a, 210b (for receiving side lead frame) Cradle part 211a, 211b (for receiving side lead frame) Opening 220 (for receiving side lead frame) Lead part 230 (for receiving side lead frame) Header Part 250 opening

Claims (5)

[Claims] 1. A light emitting side lead frame and a light receiving side lead frame, both lead frames having a pair of cradle parts, and a plurality of lead parts formed between the cradle parts and in parallel with the cradle part. , Which has a header portion formed at the tip of this lead portion, and when the header portions of both lead frames are combined so as to face each other, the cradle portions of both lead frames are overlapped. Lead frame for optical coupling device. 2. The lead frame for an optical coupling element according to claim 1, wherein the cradle portions of the both lead frames are provided with openings that are aligned when the cradle portions are stacked. 3. The lead frame for an optical coupling element according to claim 1, wherein at least one lead frame is provided with a protrusion that electrically connects the both lead frames when the both lead frames are combined. . 4. A cradle portion of one of the lead frames is provided with a projecting portion, and a cradle portion of the other lead frame is provided with an opening. When both lead frames are combined, the projecting portion is fitted into the opening. The lead frame for an optical coupling element according to claim 1, wherein the lead frame and the lead frame are combined. 5. A protrusion is provided in the cradle portion of one of the lead frames, and an opening is provided in the cradle portion of the other lead frame. When both lead frames are combined, the protrusion fits into the opening. 2. The lead frame for an optical coupling element according to claim 1, wherein the fitted portion is covered with a resin mold.