Base island structure of alternating current photoelectric coupler

Abstract

The utility model relates to the technical field of photoelectric couplers, in particular to a base island structure of an alternating current photoelectric coupler. The distance between the welding position of the light-emitting source wire and the light-emitting source can be increased through the arranged independent base islands, so that the diffusion distance from the conductive adhesive located at the light-emitting source to the welding position of the light-emitting source wire is increased, and the probability that the conductive adhesive is diffused to the welding position of the light-emitting source wire can be greatly reduced; by means of the welding piece arranged at the welding position of the light-emitting source wire, the firmness of the light-emitting source wire can be enhanced by means of the large contact area between the welding piece and the first base island, and the reliability of the light-emitting source wire is improved. In addition, electric signal transmission can be further achieved by means of the conductivity of the welding piece, and the probability of product failure can be greatly reduced; the problem that in the prior art, due to the fact that the area of the base island is small, a wire is prone to being welded to a conductive adhesive diffusion substance during secondary welding, and product failure is caused is solved.

Description

Technical Field

[0001] The utility model relates to the technical field of photoelectric couplers, in particular to a base island structure of an AC photoelectric coupler. Background Art

[0002] like Figure 1 As shown in the figure, the traditional planar AC optocoupler uses conductive glue to fix two light sources on the two base islands at the input end, then bonds are performed on the two light sources respectively, and then the other end of the wire is bonded to the other input base island end, and silicone is used to protect the chip. Then, a detector is fixed on the other side with conductive glue to receive the light signal, and then a transparent or translucent resin is plastic-sealed for light transmission. At this point, the "electric-to-photoelectric" conversion is realized, and finally the plastic-sealed protective glue is sealed to isolate the ambient light from causing leakage and other impurities such as water vapor from causing product functional problems.

[0003] However, due to the small area of the base island, the conductive glue will diffuse after dispensing, resulting in silver glue diffusion on 80% of the entire base island area. During the second soldering, if the wire is soldered on the conductive glue diffusion material, it will cause a cold solder joint and cause the product to fail. In addition, since the IR chip requires dispensing silicone to protect the IR chip from light decay, it will further affect the product CTR (current transfer ratio). Because the silicone will wrap the second solder joint, and the second solder is a fishtail soldering, it is easy to disconnect. After being shipped to the customer's end, during SMT, the product will be subjected to high temperature due to the excessive expansion coefficient of the internal silicone (the expansion coefficient is about 30×10-5 / ℃), which will generate stress and pull the gold wire, causing the second solder to disconnect, further leading to open circuit failure of the product. Utility Model Content

[0004] In view of the shortcomings of the existing technology, the present invention provides a base island structure for an AC photoelectric coupler, which solves the problem in the existing technology that due to the small base island area, the wires are easily welded on the conductive adhesive diffusion material during the second welding, causing product failure.

[0005] To achieve the above objectives, the present invention provides the following technical solutions:

[0006] A base island structure for an AC photoelectric coupler includes a first base island as an input end for respectively welding two light sources, and two second base islands for welding detectors. Protective glue is provided outside the first and second base islands, and pins extending to the outside of the conductive glue are provided on the first and second base islands. Each of the first base islands is provided with an independent base island for welding the leads of the light source on the other first base island. The welding points between the leads of the light source and the independent base islands are welded with welding pieces for pressing the leads of the light source.

[0007] Preferably, the independent base island is arranged on one side between the two first base islands.

[0008] Preferably, the two independent base islands are staggered and distributed between the two first base islands.

[0009] Preferably, one of the independent base islands is located at an end of the first base island close to the second base island, and the other independent base island is located at an end of the first base island away from the second base island.

[0010] Preferably, the distance between the whole formed by one of the first base islands and the corresponding independent base island and the whole formed by another first base island and the corresponding independent base island is 0.15 mm to 1 mm.

[0011] Preferably, the distance between the first base island and the corresponding independent base island and the second base island is 0.38 mm to 3 mm.

[0012] Preferably, the welding member is a gold ball.

[0013] Compared with the prior art, the present invention provides an island structure for an AC optocoupler, which has the following beneficial effects:

[0014] 1. The independent base island can increase the distance between the welding position of the light source wire and the light source, thereby increasing the diffusion distance of the conductive adhesive located at the light source to the welding position of the light source wire, which can greatly reduce the probability of the conductive adhesive diffusing to the welding position of the light source wire, thereby greatly reducing the probability of product failure caused by the light source wire being welded on the conductive adhesive material.

[0015] 2. By setting a welding piece at the welding position of the light source wire, the firmness of the light source wire can be enhanced by virtue of the larger contact area between the welding piece and the first base island to prevent it from falling off, and the conductive ability of the welding piece can be used to further realize the transmission of electrical signals, which can greatly reduce the probability of product failure. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] 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:

[0017] Figure 1 It is a schematic diagram of the prior art;

[0018] Figure 2 It is a schematic diagram of the utility model.

[0019] In the figure: 1. First base island; 2. Second base island; 3. Protective glue; 4. Pin; 5. Independent base island; 6. Welding part. 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 in the prior art that the wire is easily welded on the conductive adhesive diffusion material due to the small base island area during the second welding process, thereby causing product failure, this embodiment provides a base island structure of an AC optocoupler, such as Figure 2 As shown, it includes a first base island 1 as an input end for respectively welding two light sources, the light source is generally a light emitting diode, and also includes two second base islands 2 for welding detectors, the detector is used to receive the light signal emitted by the light source and convert it into an electrical signal, the first base island 1 and the second base island 2 are provided with a protective glue 3, the protective glue 3 has the functions of packaging, reflecting light and protecting, the first base island 1 and the second base island 2 are both provided with pins 4 extending to the outside of the conductive glue, the pins 4 are used to be plugged into an external circuit, and the first base island 1 is provided with an independent base island 5 for welding the lead of the light source on another first base island 1. By setting the independent base island 5, the distance between the welding position of the light source and the lead of the other light source is increased, thereby reducing the probability of the conductive glue at the light source diffusing to the independent base island 5, and reducing the probability of the lead of the light source being welded to the conductive glue diffusion material during welding. Figure 1 and Figure 2 The red oval area in the middle is the possible diffusion area of the conductive adhesive diffusion material. The welding point between the lead of the light source and the independent base island 5 is welded with a welding part 6 for pressing the lead of the light source. Even if there is a small amount of conductive adhesive at the welding point between the lead of the light source and the independent base island 5, the setting of the welding part 6 can reduce the probability of the lead of the light source being out of contact with the independent base island 5 when the conductive adhesive is subsequently expanded by high temperature due to the compression effect of the welding part 6, thereby greatly improving the reliability of the product and reducing the probability of product failure.

[0022] The independent base island 5 can be distributed around the first base island 1, but in order to facilitate the welding distance of the leads of the light source and reduce the lead cost, the independent base island 5 is set on one side between the two first base islands 1, that is, the independent base island 5 is located between the two first base islands 1, which can maximize the reduction of the welding distance of the leads of the light source, reduce the difficulty of welding, and reduce the possibility of breakage of the leads of the light source.

[0023] The two independent base islands 5 may be arranged opposite to each other or staggered with each other. In order to reduce the volume of the product and to reduce the corresponding amount of protective glue 3, the two independent base islands 5 are staggered between the two first base islands 1, thereby maximally reducing the volume of the product.

[0024] The independent base island 5 may be located at any position on one side of the position between the two first base islands 1, but in order to maximize the distance between the independent base island 5 and the welding position of the light source and reduce the probability of the conductive adhesive diffusing onto the independent base island 5, one of the independent base islands 5 is located at one end of the first base island 1 close to the second base island 2, and the other independent base island 5 is located at the end of the first base island 1 away from the second base island 2.

[0025] In order to ensure that the addition of an independent base island 5 will not affect the electrical safety of the product, the spacing between one of the first base islands 1 and another first base island 1, between one of the first base islands 1 and the non-corresponding independent base island 5, and between an independent base island 5 and another independent base island 5 needs to be set. The spacing between the whole composed of one first base island 1 and the corresponding independent base island 5 and the whole composed of another first base island 1 and the corresponding independent base island 5 is 0.15mm~1mm, which can ensure its electrical safety distance on the basis of ensuring the product size.

[0026] In order to ensure that the addition of the independent base island 5 does not affect the electrical safety of the product, the distance between the entirety of the first base island 1 and the corresponding independent base island 5 and the second base island 2 is 0.38 mm to 3 mm.

[0027] In order to improve the electrical signal transmission capability of the welding part 6, the welding part 6 is made into a gold ball according to the material of the wire on the light source. The gold ball contacts the gold wire on the light source which serves as the wire. On the one hand, the contact area between the gold ball and the first base island 1 is larger and the contact is firmer, which can achieve the purpose of pressing the wire on the light source. In addition, it can also serve the purpose of conducting electricity after contacting the wire, further ensuring the transmission of electrical signals.

[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 base island structure of an AC photoelectric coupler, comprising a first base island (1) as an input end for respectively welding two light sources, and also comprising two second base islands (2) for welding detectors, wherein a protective adhesive (3) is provided outside the first base island (1) and the second base island (2), and pins (4) extending to the outside of the conductive adhesive are provided on the first base island (1) and the second base island (2), characterized in that: Each of the first base islands (1) is provided with an independent base island (5) for welding the leads of a light source on another first base island (1), and a welding piece (6) for pressing the leads of the light source is welded at the welding point between the leads of the light source and the independent base island (5).

2. The island structure according to claim 1, wherein: The independent base island (5) is arranged on one side between the two first base islands (1).

3. The island structure according to claim 1, wherein: The two independent base islands (5) are staggered and distributed between the two first base islands (1).

4. The island structure according to claim 3, wherein: One of the independent base islands (5) is located at one end of the first base island (1) close to the second base island (2), and the other independent base island (5) is located at one end of the first base island (1) away from the second base island (2).

5. The island structure according to claim 1, wherein: The spacing between the whole formed by one of the first base islands (1) and the corresponding independent base island (5) and the whole formed by another first base island (1) and the corresponding independent base island (5) is 0.15 mm to 1 mm.

6. The island structure according to claim 1, wherein: The distance between the first base island (1) and the corresponding independent base island (5) and the second base island (2) is 0.38 mm to 3 mm.

7. The island structure according to claim 1, wherein: The welding piece (6) is a gold ball.

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