Lead frame of photoelectric coupler

Abstract

The utility model relates to the technical field of photoelectric couplers, in particular to a lead frame of a photoelectric coupler. The third base island for welding the light-emitting source wire is arranged, so that the distance between the welding position of the light-emitting source wire and the light-emitting source is greatly increased, and the conductive adhesive is more difficult to spread to the welding position for welding the light-emitting source wire on the third base island when being diffused; therefore, the probability of product failure caused by the fact that a wire is welded to a conductive adhesive diffusion substance can be greatly reduced, the third base island is arranged in a protruding mode, the conductive adhesive can be prevented from spreading to the third base island by means of the height difference between the third base island and the first base island, the conductive adhesive is further prevented from spreading to the surface of the third base island, and the product quality is improved. The probability that a light-emitting source wire is welded to a conductive adhesive diffusion substance during secondary welding is reduced; the problem that in the welding process of a lead frame of an existing alternating-current photoelectric coupler, due to the fact that the area of a base island is small, a wire of a light-emitting source can be welded to a conductive adhesive diffusion substance, and a product loses efficacy is solved.

Description

Technical Field

[0001] The utility model relates to the technical field of photoelectric couplers, in particular to a lead frame of a photoelectric coupler. Background Art

[0002] In the current lead frame welding process used to produce AC optocouplers, due to the small base island area, the conductive adhesive will diffuse into 80% of the base island area when welding the light source. Therefore, there is a high probability that it will diffuse into the wire welding point of the light source during the second welding. When the wire is welded to the conductive adhesive diffusion material, it is very likely to cause a cold solder joint and cause product failure. In addition, due to the high thermal expansion coefficient of the conductive adhesive, the high temperature may cause the conductive adhesive to expand when passing through the customer's SMT, thereby generating stress, pulling the gold wire, causing the second solder joint to fall off the base island, and thus causing the product to fail open circuit. Utility Model Content

[0003] In response to the shortcomings of the existing technology, the utility model provides a lead frame for an optocoupler, which solves the problem that during the welding process of the current AC optocoupler lead frame, due to the small base island area, the wires of the light source may be welded to the conductive adhesive diffusion material, causing the product to fail.

[0004] To achieve the above objectives, the present invention provides the following technical solutions:

[0005] A lead frame for an AC photoelectric coupler includes two symmetrically arranged side rails and a plurality of connecting ribs arranged between the two side rails. Two first base islands for mounting a light source and two second base islands as output ends for mounting detectors are arranged between any two connecting ribs. Pins are provided on both the first and second base islands. A third base island is provided on the first base island, extending toward a side away from the mounting position of the light source.

[0006] Preferably, the third base island is arranged on one side between the two first base islands.

[0007] Preferably, the two third base islands are staggered and distributed between the two first base islands.

[0008] Preferably, one of the third base islands is located at an end of the first base island close to the second base island, and the other third base island is located at an end of the first base island away from the second base island.

[0009] Preferably, the third base island protrudes toward the side where the light source is installed.

[0010] Preferably, the length of the side rail is 200mm-220mm.

[0011] Preferably, the outer edge distance between the two side rails 1 is 66 mm-80 mm.

[0012] Compared with the prior art, the present invention provides a lead frame for an optocoupler, which has the following beneficial effects:

[0013] 1. By setting up a third base island for welding the light source wire, the distance between the welding position of the light source wire and the position of the light source can be greatly increased, so that when the conductive glue spreads, it is more difficult to spread to the welding position of the light source wire on the third base island, thereby greatly reducing the probability of product failure caused by the wire being welded on the conductive glue diffusion material.

[0014] 2. By providing a raised third base island, the height difference between the third base island and the first base island can be used to prevent the conductive adhesive from spreading to the third base island, thereby further improving the reliability of the third base island and further preventing the conductive adhesive from spreading to the surface of the third base island. This reduces the probability of the light source wire being welded to the conductive adhesive diffusion material during the second welding process, thereby reducing the probability of product failure. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0016] Figure 1 A size comparison diagram of the lead frame of the present invention and the existing lead frame;

[0017] Figure 2 For this utility model Figure 1 A magnified schematic diagram of point A in the middle;

[0018] Figure 3 This is a schematic diagram of the third base island of the present invention.

[0019] In the figure: 1, side rail; 2, connecting reinforcement; 3, first base island; 4, second base island; 5, pin; 6, third base island. DETAILED DESCRIPTION

[0020] The following will describe the implementation methods of the present application in detail with reference to the accompanying drawings and examples, so that the implementation process of how the present application applies technical means to solve technical problems and achieve technical effects can be fully understood and implemented accordingly.

[0021] In order to solve the problem that during the welding process of the lead frame of the current AC photoelectric coupler, the wires of the light source may be welded to the conductive adhesive diffusion material due to the small base island area, thereby causing the product to fail, this embodiment provides a lead frame of an AC photoelectric coupler, including two symmetrically arranged side rails 1 and a plurality of connecting ribs 2 arranged between the two side rails 1. Two first base islands 3 for mounting the light source are arranged between any two connecting ribs 2, and two second base islands 4 as output ends for mounting detectors. The detectors are used to receive the light signal emitted by the light source and convert it into an electrical signal. The first base islands 3 and The second base island 4 is provided with a pin 5, and the first base island 3 is provided with a third base island 6 extending to the side away from the installation position of the light source. When the light source is welded to the first base island 3 during the first welding, the conductive glue at its bottom will spread to the surrounding areas. Since the third base island 6 is far away from the light source on the first base island 3, the probability that the conductive glue can spread to the welding position of the light source wire on the first base island 3 for welding is low. Therefore, during the second welding, the probability of the wire on the light source being welded to the conductive glue diffusion material can be reduced, thereby greatly reducing the probability of product failure caused by the wire being welded to the conductive glue diffusion material.

[0022] Theoretically, the third base island 6 can be set at any position around the first base island 3. However, in order to shorten the length of the light source wire, since the wire is generally a gold wire, its cost can be reduced and the probability of the light source wire breaking due to excessive length can also be reduced. Therefore, the third base island 6 is set on one side between the two first base islands 3, which can greatly reduce the probability of the light source wire being pulled apart.

[0023] When the two third base islands 6 are located between the two first base islands 3, their positions may be staggered or opposite. When they are opposite, the amount of encapsulation colloid used will increase, and the length of the light source wire will also increase, which is more disadvantageous than advantageous. Therefore, staggering the two third base islands 6 between the two first base islands 3 can greatly reduce the size of the product and also reduce the cost.

[0024] The third base island 6 can be located at any side edge on one side between the two first base islands 3. In order to increase the distance between the position for welding the light source wire on the third base island 6 and the light source installation position as much as possible, and reduce the probability of the conductive adhesive spreading to the position for welding the light source wire on the third base island 6, one of the third base islands 6 is located at one end of the first base island 3 close to the second base island 4, and the other third base island 6 is located at one end of the first base island 3 away from the second base island 4, thereby maximizing the position of the third base island 6 and the light source, which can greatly reduce the probability of the wire being welded to the conductive adhesive diffusion material during subsequent welding.

[0025] Based on the principle that fluid flows downward when diffusing, when the position of the third base island 6 is higher than the position of the plane where the first base island 3 is located, the conductive glue can be prevented from flowing onto the third base island 6 through the connection between the two. Therefore, the third base island 6 is raised toward the side where the light source is installed. Figure 3 As shown, the light source is mounted on the upper surface of the first base island 3 .

[0026] During the production process, the existing lead frame is too long and easily bends during operation, causing abnormalities and loss of yield. Therefore, the length of the side rail 1 is set to 200mm-220mm, which can maximize the number of products while ensuring the yield.

[0027] When the lead frame length is reduced, the width is relatively narrow, resulting in insufficient product density, high bracket unit price, and inconvenient operation. Therefore, the outer distance between the two side rails 1 is set to 66mm-80mm, and the overall width is increased to increase the product density. Figure 1 As shown, the lead frame marked as H1 has a size of a conventional lead frame, and the lead frame marked as H2 has a size of the lead frame of this embodiment.

[0028] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus.

[0029] Although the embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A lead frame for a photoelectric coupler, comprising two symmetrically arranged side rails (1), and a plurality of connecting ribs (2) arranged between the two side rails (1), two first base islands (3) for mounting a light source, and two second base islands (4) as output ends for mounting a detector, are arranged between any two connecting ribs (2), and pins (5) are provided on both the first base islands (3) and the second base islands (4), characterized in that: A third base island (6) is provided on the first base island (3) and extends towards a side away from the light source installation position.

2. The lead frame of a photocoupler according to claim 1, wherein: The third base island (6) is arranged on one side between the two first base islands (3).

3. The lead frame of a photocoupler according to claim 1, wherein: The two third base islands (6) are staggered and distributed between the two first base islands (3).

4. The lead frame of a photocoupler according to claim 3, wherein: One of the third base islands (6) is located at one end of the first base island (3) close to the second base island (4), and the other third base island (6) is located at one end of the first base island (3) away from the second base island (4).

5. The lead frame of a photocoupler according to claim 1, wherein: The third base island (6) protrudes toward the side where the light source is installed.

6. The lead frame of a photocoupler according to claim 1, wherein: The length of the side rail (1) is 200 mm to 220 mm.

7. The lead frame of a photocoupler according to claim 1, wherein: The outer distance between the two side rails (1) is 66mm-80mm.

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