Bidirectional TVS device

Abstract

The utility model discloses a bidirectional TVS (Transient Voltage Suppressor) device, which comprises a first chip, a second chip and an epoxy packaging body which are parallel and oppositely arranged, and the negative electrode surface of the first chip is electrically connected with the negative electrode surface of the second chip through a first soldering paste layer. The positive electrode faces of the first chip and the second chip which are vertically arranged are electrically connected with a welding disc through a second welding paste layer, the first chip, the second chip and the welding disc are all wrapped in an epoxy packaging body, and each welding disc is provided with a pin part extending to the outer side of the epoxy packaging body in the horizontal direction. The area of the surfaces of the sides, facing the first chip and the second chip, of the bonding pads is smaller than the area of the surfaces of the sides, facing the bonding pads, of the first chip and the second chip, and the surface of the side, welded to the first chip or the second chip, of each bonding pad is provided with a plurality of wire grooves arranged at intervals. According to the utility model, on the basis that circuit elements are protected from transient high-voltage impact, the stability of the overall structure and performance of the device can be improved.

Description

Technical Field

[0001] The utility model relates to the technical field of semiconductor power devices, in particular to a bidirectional TVS device. Background Art

[0002] Transient voltage suppression diodes (TVS) are widely used in electrostatic and overvoltage protection for semiconductors, sensitive parts, secondary power supplies, and signal circuits. TVS has many advantages such as small size, high power, fast response, no noise, reliable performance, and long service life. The damage of electronic components is divided into sudden damage and latent damage. Sudden damage refers to partial damage to the device and loss of function. Latent damage refers to partial damage to the device, but the function has not been lost, and it cannot be found in the production process test, but it will make the product unstable during use, sometimes good and sometimes bad, thus posing a greater threat to product quality. With the widespread use of TVS devices, how to reduce and improve the stability of product quality and avoid potential damage has become a problem that needs to be solved. Utility Model Content

[0003] The utility model aims to provide a bidirectional TVS device, which can protect circuit components from transient high-voltage shocks, avoid chip leaks, and avoid chip deflection during welding due to excessive thickness of the solder paste layer, thereby affecting welding stability, thereby improving the stability of the overall structure and performance of the device.

[0004] To achieve the above-mentioned purpose, the technical solution adopted by the utility model is: a bidirectional TVS device, comprising: a first chip, a second chip and an epoxy package body arranged in parallel and facing each other, the negative electrode surface of the first chip is electrically connected to the negative electrode surface of the second chip through a first solder paste layer, and the positive electrode surfaces of the vertically arranged first chip and second chip are electrically connected to a welding pad through a second solder paste layer, the first chip, the second chip and the welding pad are all encapsulated in the epoxy package body, each of the welding pads has a pin portion extending to the outside of the epoxy package body in a horizontal direction, the area of ​​the surface of the welding pad facing the first chip and the second chip is smaller than the area of ​​the surface of the first chip and the second chip facing the welding pad, and a plurality of spaced wire grooves are provided on the surface of each welding pad on the side where it is welded to the first chip or the second chip.

[0005] The further improved scheme in the above technical scheme is as follows:

[0006] 1. In the above solution, the first solder paste layer and the second solder paste layer are both tin paste layers.

[0007] 2. In the above solution, a protrusion is formed on the surface of each of the first chip and the second chip, which is opposite to the welding pad.

[0008] 3. In the above solution, the surface of the welding pad on the side where the first chip and the second chip are welded is a circular surface.

[0009] 4. In the above solution, each of the three wire grooves extends in the radial direction of the surface of the welding disk and is evenly spaced in the circumferential direction.

[0010] 5. In the above solution, the wire trough is a fan-shaped wire trough or a strip-shaped wire trough.

[0011] 6. In the above solution, the three wire grooves are connected at the center of the welding disk.

[0012] Due to the application of the above technical solution, the utility model has the following advantages and effects compared with the prior art:

[0013] The utility model bidirectional TVS device has a first chip and a second chip whose negative electrode surface is electrically connected through a first solder paste layer, and a first chip and a second chip whose positive electrode surfaces are vertically arranged are electrically connected to a welding pad through a second solder paste layer. The first chip, the second chip and the welding pad are all encapsulated in an epoxy package, and each welding pad has a pin portion extending to the outside of the epoxy package in a horizontal direction. The surface area of ​​the welding pad facing the first chip and the second chip is smaller than the surface area of ​​the first chip and the second chip facing the welding pad. A plurality of wire grooves are provided on the surface of the side where each welding pad is welded to the first chip or the second chip. On the basis of protecting the circuit elements from transient high voltage impact, the chip can be prevented from being leaked and the situation where the chip is deflected during welding due to the excessive thickness of the solder paste layer locally, which affects the welding stability, thereby improving the stability of the overall structure and performance of the device. In addition, a convex portion is formed on the surface of the first chip and the second chip on the side opposite to the welding pad, thereby improving the strength and stability of the welding structure between the two chips, thereby improving the stability of the overall performance of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Attached Figure 1 It is a structural schematic diagram of the bidirectional TVS device of the utility model;

[0015] Attached Figure 2 It is a front view of the welding plate in Example 1 of the utility model;

[0016] Attached Figure 3 This is a front view of the welding plate in Example 2 of the utility model.

[0017] In the above figures: 1, first chip; 2, second chip; 3, epoxy package; 41, first solder paste layer; 42, second solder paste layer; 5, solder pad; 6, pin portion; 7, wire groove; 8, protrusion. DETAILED DESCRIPTION

[0018] The utility model is further described below in conjunction with the accompanying drawings and embodiments:

[0019] Embodiment 1: A bidirectional TVS device comprises: a first chip 1, a second chip 2 and an epoxy package 3 arranged in parallel and facing each other, the negative electrode surface of the first chip 1 is electrically connected to the negative electrode surface of the second chip 2 through a first solder paste layer 41, and the positive electrode surfaces of the vertically arranged first chip 1 and second chip 2 are electrically connected to a welding pad 5 through a second solder paste layer 42, the first chip 1, the second chip 2 and the welding pad 5 are all encapsulated in the epoxy package 3, each of the welding pads 5 has a pin portion 6 extending to the outside of the epoxy package 3 in a horizontal direction, the area of ​​the surface of the welding pad 5 facing the first chip 1 and the second chip 2 is smaller than the area of ​​the surface of the first chip 1 and the second chip 2 facing the welding pad 5, and a plurality of spaced wire grooves 7 are provided on the surface of each welding pad 5 on the side where it is welded to the first chip 1 or the second chip 2, the wire grooves can provide overflow and material leveling space for the molten solder paste during the welding process, and avoid chip skewness due to uneven solder layer thickness while achieving good welding.

[0020] The first solder paste layer 41 and the second solder paste layer 42 are both solder paste layers;

[0021] The surface of the welding pad 5 on the side where the first chip 1 and the second chip 2 are welded is a circular surface;

[0022] The three wire grooves 7 each extend in the radial direction of the surface of the welding plate 5 and are evenly spaced in the circumferential direction;

[0023] like Figure 2 As shown, the wire groove 7 is a fan-shaped wire groove.

[0024] Embodiment 2: A bidirectional TVS device comprises: a first chip 1, a second chip 2 and an epoxy package 3 arranged in parallel and facing each other, the negative electrode surface of the first chip 1 is electrically connected to the negative electrode surface of the second chip 2 through a first solder paste layer 41, and the positive electrode surfaces of the vertically arranged first chip 1 and second chip 2 are electrically connected to a welding pad 5 through a second solder paste layer 42, the first chip 1, the second chip 2 and the welding pad 5 are all encapsulated in the epoxy package 3, each of the welding pads 5 has a pin portion 6 extending horizontally to the outside of the epoxy package 3, the area of ​​the surface of the welding pad 5 facing the first chip 1 and the second chip 2 is smaller than the area of ​​the surface of the first chip 1 and the second chip 2 facing the welding pad 5, and a plurality of spaced wire grooves 7 are provided on the surface of each welding pad 5 on the side where it is welded to the first chip 1 or the second chip 2.

[0025] A protrusion 8 is formed on the surface of each of the first chip 1 and the second chip 2 on the side opposite to the welding pad 5;

[0026] The surface of the welding pad 5 on the side where the first chip 1 and the second chip 2 are welded is a circular surface;

[0027] The three wire grooves 7 each extend in the radial direction of the surface of the welding plate 5 and are evenly spaced in the circumferential direction;

[0028] like Figure 3 As shown, the wire groove 7 is a strip-shaped wire groove; the three wire grooves 7 are connected at the center of the welding plate 5, which can further improve the uniformity of the overflow of the solder paste.

[0029] When the above-mentioned bidirectional TVS device is used, it can not only protect the circuit components from transient high-voltage shocks, but also avoid the chip from being leaked and the chip from being deflected during the welding process due to the local excessive thickness of the solder paste layer, thereby affecting the welding stability, thereby improving the stability of the overall structure and performance of the device; in addition, it can improve the strength and stability of the welding structure between the two chips, thereby improving the stability of the overall performance of the device.

[0030] The above embodiments are only for illustrating the technical concept and features of the utility model, and their purpose is to enable people familiar with the technology to understand the content of the utility model and implement it accordingly, and they cannot be used to limit the protection scope of the utility model. Any equivalent changes or modifications made according to the spirit of the utility model should be included in the protection scope of the utility model.

Claims

1. A bidirectional TVS device, comprising: A first chip (1), a second chip (2) and an epoxy package (3) are arranged in parallel and facing each other, the negative electrode surface of the first chip (1) and the negative electrode surface of the second chip (2) are electrically connected via a first solder paste layer (41), and the characteristics are as follows: the positive electrode surface of each of the vertically arranged first chip (1) and second chip (2) is electrically connected to a welding pad (5) via a second solder paste layer (42), the first chip (1), the second chip (2) and the welding pad (5) are all encapsulated in the epoxy package (3), each of the welding pads (5) has a pin portion (6) extending horizontally to the outside of the epoxy package (3), the area of ​​the surface of the welding pad (5) facing the first chip (1) or the second chip (2) is smaller than the area of ​​the surface of the first chip (1) or the second chip (2) facing the welding pad (5), and a plurality of wire grooves (7) arranged at intervals are provided on the surface of each welding pad (5) on the side where it is welded to the first chip (1) or the second chip (2).

2. The bidirectional TVS device according to claim 1, characterized in that: The first solder paste layer (41) and the second solder paste layer (42) are both tin paste layers.

3. The bidirectional TVS device according to claim 1, characterized in that: A protrusion (8) is formed on the surface of each of the first chip (1) and the second chip (2) on the side opposite to the welding pad (5).

4. The bidirectional TVS device according to claim 1, characterized in that: The surface of the welding pad (5) on the side where it is welded to the first chip (1) and the second chip (2) is a circular surface.

5. The bidirectional TVS device according to claim 4, characterized in that: The three wire grooves (7) each extend in a radial direction of the surface of the welding plate (5) and are distributed at equal intervals in the circumferential direction.

6. The bidirectional TVS device according to claim 1, 4 or 5, characterized in that: The wire trough (7) is a fan-shaped wire trough or a strip-shaped wire trough.

7. The bidirectional TVS device according to claim 5, characterized in that: The three wire grooves (7) are connected at the center of the welding plate (5).

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