Bidirectional transient voltage suppression devices

Abstract

The utility model discloses a bidirectional transient voltage suppression device, comprising: a first chip, a second chip, an epoxy package body coated on the outside of the first chip and the second chip, a first pin and a second pin, one end of each of the first pin and the second pin is located outside the epoxy package body, the negative electrode surfaces of the first chip and the second chip stacked opposite to each other are electrically connected, the positive electrode surface of the vertically arranged first chip is electrically connected to a first connection portion of a first terminal, the positive electrode surface of the second chip is electrically connected to a second connection portion of a second terminal, the first lead portion of the first terminal is welded to an end of the first pin located in the epoxy package body at one end opposite to the first connection portion, and the second lead portion of the second terminal is welded to an end of the second pin located in the epoxy package body at one end opposite to the second connection portion. The utility model improves the stability and reliability of the performance of the device during long-term use on the basis of protecting circuit components from transient high voltage shocks.

Description

Technical Field

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

[0002] Transient voltage suppressors protect circuits and electronic components from damage by static electricity and surge pulses, or even failure. Generally, TVS is connected in parallel at both ends of the protected circuit and is in standby mode. When both ends of the circuit are impacted by transient pulses or surge currents, and the pulse amplitude exceeds the breakdown voltage of the TVS, the TVS can quickly change the impedance at both ends from high impedance to low impedance to achieve conduction and absorb transient pulses. When using axial transient voltage suppressors, it is generally necessary to bend the pins. The stress generated during the bending process can easily cause adverse effects on the chip, resulting in poor stability of the overall device. Utility Model Content

[0003] The utility model aims to provide a bidirectional transient voltage suppression device, which can protect circuit components from transient high voltage impact and improve the stability and reliability of the performance of the device during long-term use.

[0004] To achieve the above-mentioned purpose, the technical solution adopted by the utility model is: a bidirectional transient voltage suppression device, comprising: a first chip, a second chip, an epoxy package body coated on the outside of the first chip and the second chip, a first pin and a second pin, one end of each of the first pin and the second pin is located on the outside of the epoxy package body, the negative electrode surfaces of the first chip and the second chip stacked opposite to each other are electrically connected, the positive electrode surface of the vertically arranged first chip is electrically connected to the first connecting portion of a first terminal, the positive electrode surface of the second chip is electrically connected to the second connecting portion of a second terminal, the first lead portion of the first terminal is welded to one end of the first pin located in the epoxy package body at one end opposite to the first connecting portion, and the second lead portion of the second terminal is welded to one end of the second pin located in the epoxy package body at one end opposite to the second connecting portion.

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

[0006] 1. In the above scheme, a first overlapping portion is provided at one end of the first lead portion opposite to the first connecting portion, and the first overlapping portion is covered on the outside of the first pin and is welded and connected to the first pin through solder paste. A second overlapping portion is provided at one end of the second lead portion opposite to the second connecting portion, and the second overlapping portion is covered on the outside of the second pin and is welded and connected to the second pin through solder paste.

[0007] 2. In the above solution, the first connecting portion and the second connecting portion are both disc portions arranged parallel to the first chip and the second chip.

[0008] 3. In the above solution, the first chip and the second chip, the first chip and the first connecting portion, and the second chip and the second connecting portion are all connected by welding through a solder sheet.

[0009] Due to the application of the above technical solution, the utility model has the following advantages and effects compared with the prior art:

[0010] The utility model bidirectional transient voltage suppression device has a positive electrode surface of the first chip arranged vertically electrically connected to a first connection portion of a first terminal, a positive electrode surface of the second chip electrically connected to a second connection portion of a second terminal, a first lead portion of the first terminal opposite to the first connection portion is welded to an end of the first pin located in the epoxy package, and a second lead portion of the second terminal opposite to the second connection portion is welded to an end of the second pin located in the epoxy package. On the basis of protecting circuit elements from transient high voltage shock, stress transmission generated when the pin is bent during use can be effectively avoided. The situation in which the chip performance is affected by the plastic package body is improved, and the performance stability and reliability of the device during long-term use are improved; further, a first overlapping portion is provided at one end of the first lead portion opposite to the first connecting portion, and the first overlapping portion is coated on the outside of the first pin and is welded and connected to the first pin through solder paste; a second overlapping portion is provided at one end of the second lead portion opposite to the second connecting portion, and the second overlapping portion is coated on the outside of the second pin and is welded and connected to the second pin through solder paste, which can not only improve the stability of the connection structure at the welding point, but also enhance the bonding strength with the epoxy, and further improve the stability of the overall performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Attached Figure 1 It is a schematic diagram of the structure of the bidirectional transient voltage suppression device of the utility model;

[0012] Attached Figure 2 It is a schematic diagram of the local structure of the overlap between the first pin and the first overlap portion in Example 2;

[0013] Attached Figure 3 is a schematic diagram of the local structure of the overlap between the second pin and the second overlap portion in Embodiment 2;

[0014] Attached Figure 4 This is a structural cross-sectional view of the welding point between the second pin and the second overlapping portion in Example 2.

[0015] In the above figures: 1, first chip; 2, second chip; 3, epoxy package; 41, first pin; 42, second pin; 5, first terminal; 51, first connecting part; 52, first lead part; 53, first overlapping part; 6, second terminal; 61, second connecting part; 62, second lead part; 63, second overlapping part; 7, solder sheet. DETAILED DESCRIPTION

[0016] The utility model is further described below in conjunction with the accompanying drawings and embodiments:

[0017] Embodiment 1: A bidirectional transient voltage suppression device comprises: a first chip 1, a second chip 2, an epoxy package body 3 wrapped around the outside of the first chip 1 and the second chip 2, a first pin 41 and a second pin 42, wherein one end of each of the first pin 41 and the second pin 42 is located outside the epoxy package body 3, the negative electrode surfaces of the first chip 1 and the second chip 2 stacked opposite to each other are electrically connected, the positive electrode surface of the vertically arranged first chip 1 is electrically connected to a first connecting portion 51 of a first terminal 5, the positive electrode surface of the second chip 2 is electrically connected to a second connecting portion 61 of a second terminal 6, the first lead portion 52 of the first terminal 5 is welded to one end of the first pin 41 located in the epoxy package body 3 at one end opposite to the first connecting portion 51, and the second lead portion 62 of the second terminal 6 is welded to one end of the second pin 42 located in the epoxy package body 3 at one end opposite to the second connecting portion 61.

[0018] The first connecting portion 51 and the second connecting portion 61 are both disc portions arranged parallel to the first chip 1 and the second chip 2;

[0019] The first chip 1 and the second chip 2 , the first chip 1 and the first connecting portion 51 , and the second chip 2 and the second connecting portion 61 are all connected by welding via a solder sheet 7 .

[0020] Embodiment 2: A bidirectional transient voltage suppression device comprises: a first chip 1, a second chip 2, an epoxy package body 3 wrapped around the outside of the first chip 1 and the second chip 2, a first pin 41 and a second pin 42, wherein one end of each of the first pin 41 and the second pin 42 is located outside the epoxy package body 3, the negative electrode surfaces of the first chip 1 and the second chip 2 stacked opposite to each other are electrically connected, the positive electrode surface of the vertically arranged first chip 1 is electrically connected to a first connecting portion 51 of a first terminal 5, the positive electrode surface of the second chip 2 is electrically connected to a second connecting portion 61 of a second terminal 6, the first lead portion 52 of the first terminal 5 is welded to one end of the first pin 41 located in the epoxy package body 3 at one end opposite to the first connecting portion 51, and the second lead portion 62 of the second terminal 6 is welded to one end of the second pin 42 located in the epoxy package body 3 at one end opposite to the second connecting portion 61.

[0021] The first lead portion 52 is provided with a first lap portion 53 at one end opposite to the first connecting portion 51, and the first lap portion 53 is covered on the outer side of the first pin 41 and is welded and connected to the first pin 41 through solder paste. The second lead portion 62 is provided with a second lap portion 63 at one end opposite to the second connecting portion 61, and the second lap portion 63 is covered on the outer side of the second pin 42 and is welded and connected to the second pin 42 through solder paste.

[0022] When the above-mentioned bidirectional transient voltage suppression device is used, it can effectively avoid the stress generated when the pins are bent during use from being transmitted to the inside of the plastic package and affecting the chip performance, based on protecting the circuit components from transient high voltage impacts, thereby improving the stability and reliability of the performance of the device during long-term use; further, it can not only improve the stability of the connection structure at the welding point, but also enhance the bonding strength between the solder joint and the epoxy, further improving the stability of the overall performance.

[0023] 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 transient voltage suppression device, comprising: A first chip (1), a second chip (2), an epoxy package (3) wrapped around the outside of the first chip (1) and the second chip (2), a first pin (41) and a second pin (42), wherein one end of each of the first pin (41) and the second pin (42) is located outside the epoxy package (3), and the negative electrode surfaces of the first chip (1) and the second chip (2) stacked opposite to each other are electrically connected, characterized in that: the positive electrode surface of the vertically arranged first chip (1) is electrically connected to a first connecting portion (51) of a first terminal (5), the positive electrode surface of the second chip (2) is electrically connected to a second connecting portion (61) of a second terminal (6), an end of a first lead portion (52) of the first terminal (5) opposite to the first connecting portion (51) is welded to an end of the first pin (41) located inside the epoxy package (3), and an end of a second lead portion (62) of the second terminal (6) opposite to the second connecting portion (61) is welded to an end of the second pin (42) located inside the epoxy package (3).

2. The bidirectional transient voltage suppression device according to claim 1, characterized in that: A first lap joint (53) is provided at one end of the first lead portion (52) opposite to the first connecting portion (51); the first lap joint (53) is wrapped around the outside of the first pin (41) and is welded to the first pin (41) via solder paste; and a second lap joint (63) is provided at one end of the second lead portion (62) opposite to the second connecting portion (61); the second lap joint (63) is wrapped around the outside of the second pin (42) and is welded to the second pin (42) via solder paste.

3. The bidirectional transient voltage suppression device according to claim 1, characterized in that: The first connecting portion (51) and the second connecting portion (61) are both disc portions arranged parallel to the first chip (1) and the second chip (2).

4. The bidirectional transient voltage suppression device according to claim 1, characterized in that: The first chip (1) and the second chip (2), the first chip (1) and the first connecting portion (51), and the second chip (2) and the second connecting portion (61) are all connected by welding via a solder sheet (7).

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