Bidirectional tvs protection device

Abstract

The utility model discloses a bidirectional TVS protection device, include: first TVS chip, second TVS chip, connecting piece, first lead frame and second lead frame, one end of this second lead frame has a second pad piece, and the one end of connecting piece close to TVS chip is first pad piece, four corners of second pad piece all have second V-shaped gap, and first TVS chip is located in the central region of second pad piece, and four second V-shaped gaps are located in the outside of the central region of second pad piece, four corners of first pad piece all have first V-shaped gap, and second TVS chip is located in the central region of first pad piece, and one insulating package is covered on first TVS chip, second TVS chip, first pad piece, second pad piece and the one end of first lead frame and second lead frame close to TVS chip. The utility model can avoid the lead frame and connecting piece in its inside from the reason such as vibration and temperature change and so on and make the TVS chip and the component connected with it separate, and the reliability of bidirectional TVS protection device is increased.

Description

Technical Field

[0001] This utility model relates to a bidirectional TVS protection device, belonging to the technical field of overvoltage protection devices. Background Technology

[0002] As electronic devices develop towards higher density and higher reliability, the performance requirements for TVS circuit protection components are becoming increasingly stringent. TVS, also known as transient voltage suppressor diode, is essentially a semiconductor device based on a PN junction. TVS protection devices are widely used in circuit protection. When a transient voltage exceeds the breakdown voltage of the TVS protection device, its PN junction rapidly avalanche breaks down, and the impedance drops from the megaohm level to the ohm level, clamping the voltage within a safe range. At the same time, the TVS protection device is grounded, providing a low-impedance conduction path to prevent excessive voltage surges from damaging downstream precision electronic components. Bidirectional TVS protection devices, as a special structural form, are characterized by symmetrical current-voltage characteristics, which can effectively absorb and clamp transient overvoltages in both positive and negative directions. In current bidirectional TVS protection devices, when exposed to vibration or temperature changes, the internal components are prone to displacement, making it easy for the components to disconnect. Therefore, how to solve the above problems has become an urgent technical issue. Summary of the Invention

[0003] The purpose of this invention is to provide a bidirectional TVS protection device that can prevent the internal lead frame and connecting piece from separating from their predetermined positions due to vibration and temperature changes, thereby preventing the TVS chip from separating from the components it is connected to, thus increasing the reliability of the bidirectional TVS protection device.

[0004] To achieve the above objectives, the technical solution adopted by this utility model is: a bidirectional TVS protection device, comprising: a first TVS chip, a second TVS chip, a connecting piece, a first lead frame and a second lead frame, wherein one end of the second lead frame has a second pad, and the end of the connecting piece near the TVS chip is the first pad. The second pad, the first TVS chip, the second TVS chip, and the connecting piece are stacked at one end, and the cathode of the first TVS chip and the cathode of the second TVS chip are connected through a middle solder paste layer. The anode of the first TVS chip is connected to the second pad located below it through a lower solder paste layer, and the anode of the second TVS chip is connected to the first pad located above it through an upper solder paste layer. The other end of the connecting piece is connected to one end of the first lead frame, and the ends of the first lead frame and the second lead frame opposite to the TVS chip are respectively the negative pin and the positive pin; The second pad has a second V-shaped notch at each of its four corners, the first TVS chip is located in the central area of ​​the second pad, and the four second V-shaped notches are located outside the central area of ​​the second pad; the first pad has a first V-shaped notch at each of its four corners, the second TVS chip is located in the central area of ​​the first pad, and the four first V-shaped notches are located outside the central area of ​​the first pad. An insulating package covers a first TVS chip, a second TVS chip, a first pad, a second pad, and a first lead frame and a second lead frame near one end of the TVS chip.

[0005] The following are further improvements to the above technical solution: 1. In the above scheme, a metal mesh layer is provided in the middle solder paste layer.

[0006] 2. In the above scheme, the warp and weft lines in the metal mesh layer are arranged perpendicularly.

[0007] 3. In the above scheme, the negative electrode pin extends from the insulating package body, and the negative electrode pin is composed of a negative electrode side pin portion located on the side wall of the insulating package body and a negative electrode bottom pin portion located at the bottom of the insulating package body.

[0008] 4. In the above scheme, the positive electrode pin extends from the insulating package body, and the positive electrode pin is composed of a positive electrode side pin portion located on the side wall of the insulating package body and a positive electrode bottom pin portion located at the bottom of the insulating package body.

[0009] Due to the application of the above technical solution, this utility model has the following advantages compared with the prior art: This utility model relates to a bidirectional TVS protection device, wherein each of the four corners of the second pad has a second V-shaped notch, the first TVS chip is located in the central area of ​​the second pad, and the four second V-shaped notches are located outside the central area of ​​the second pad; each of the four corners of the first pad has a first V-shaped notch, the second TVS chip is located in the central area of ​​the first pad, and the four first V-shaped notches are located outside the central area of ​​the first pad; an insulating package covers the first TVS chip, the second TVS chip, the first pad, the second pad, and the first and second lead frames near the TVS chip ends. The V-shaped notches on the pads ensure that the lead frame where the second pad is located and the connecting piece where the first pad is located can be firmly bonded to the insulating package, preventing the lead frame and connecting piece from separating from their intended positions due to vibration and temperature changes, thus increasing the reliability of the bidirectional TVS protection device. Attached Figure Description

[0010] AppendixFigure 1 This is a schematic diagram of the structure of the bidirectional TVS protection device of this utility model; Appendix Figure 2 For the appendix Figure 1 Cross-sectional view from the perspective of the middle AA (analogous to ... Appendix Figure 3 For the appendix Figure 1 Cross-sectional view from the perspective of the middle BB.

[0011] In the above figures: 1. First TVS chip; 2. Connector; 3. First lead frame; 4. Second lead frame; 5. Second pad; 61. Lower solder paste layer; 62. Upper solder paste layer; 7. Negative lead; 8. Positive lead; 9. Second V-shaped notch; 10. Insulating package; 11. Second TVS chip; 12. First pad; 13. First V-shaped notch; 14. Middle solder paste layer. Detailed Implementation

[0012] The present patent can be further understood through the specific embodiments given below, but they are not intended to limit the present patent.

[0013] Example 1: A bidirectional TVS protection device includes: a first TVS chip 1, a second TVS chip 11, a connecting piece 2, a first lead frame 3 and a second lead frame 4, one end of the second lead frame 4 having a second pad 5, and the end of the connecting piece 2 near the TVS chip being the first pad 12. The second solder pad 5, the first TVS chip 1, the second TVS chip 11, and the connecting piece 2 are stacked at one end, and the cathode of the first TVS chip 1 and the cathode of the second TVS chip 11 are connected through the middle solder paste layer 14. The anode of the first TVS chip 1 is connected to the second pad 5 located below it through the lower solder paste layer 61, and the anode of the second TVS chip 11 is connected to the first pad 12 located above the connecting piece 2 through the upper solder paste layer 62. The other end of the connecting piece 2 is connected to one end of the first lead frame 3. The ends of the first lead frame 3 and the second lead frame 4 that are opposite to the TVS chip 1 are respectively the negative pin 7 and the positive pin 8. The second pad 5 has a second V-shaped notch 91 at each of its four corners. The first TVS chip 1 is located in the central area of ​​the second pad 5, and the four second V-shaped notches 91 are located outside the central area of ​​the second pad 5. The first pad 12 has a first V-shaped notch 13 at each of its four corners. The second TVS chip 11 is located in the central area of ​​the first pad 12, and the four first V-shaped notches 13 are located outside the central area of ​​the first pad 12. An insulating package 10 covers the first TVS chip 1, the second TVS chip 11, the first pad 12, the second pad 5, and the first lead frame 3 and the second lead frame 4 near one end of the TVS chip 1.

[0014] The aforementioned negative electrode pin 7 extends from inside the insulating package 10. This negative electrode pin 7 consists of a negative electrode side pin portion located on the side wall of the insulating package 10 and a negative electrode bottom pin portion located at the bottom of the insulating package 10.

[0015] The aforementioned positive pin 8 extends from inside the insulating package 10. This positive pin 8 consists of a positive side pin portion located on the side wall of the insulating package 10 and a positive bottom pin portion located at the bottom of the insulating package 10.

[0016] Example 2: A bidirectional TVS protection device includes: a first TVS chip 1, a second TVS chip 11, a connecting piece 2, a first lead frame 3 and a second lead frame 4, one end of the second lead frame 4 having a second pad 5, and the end of the connecting piece 2 near the TVS chip being the first pad 12. The second solder pad 5, the first TVS chip 1, the second TVS chip 11, and the connecting piece 2 are stacked at one end, and the cathode of the first TVS chip 1 and the cathode of the second TVS chip 11 are connected through the middle solder paste layer 14. The anode of the first TVS chip 1 is connected to the second pad 5 located below it through the lower solder paste layer 61, and the anode of the second TVS chip 11 is connected to the first pad 12 located above the connecting piece 2 through the upper solder paste layer 62. The other end of the connecting piece 2 is connected to one end of the first lead frame 3. The ends of the first lead frame 3 and the second lead frame 4 that are opposite to the TVS chip 1 are respectively the negative pin 7 and the positive pin 8. The second pad 5 has a second V-shaped notch 91 at each of its four corners. The first TVS chip 1 is located in the central area of ​​the second pad 5, and the four second V-shaped notches 91 are located outside the central area of ​​the second pad 5. The first pad 12 has a first V-shaped notch 13 at each of its four corners. The second TVS chip 11 is located in the central area of ​​the first pad 12, and the four first V-shaped notches 13 are located outside the central area of ​​the first pad 12. An insulating package 10 covers the first TVS chip 1, the second TVS chip 11, the first pad 12, the second pad 5, and the first lead frame 3 and the second lead frame 4 near one end of the TVS chip 1.

[0017] A metal mesh layer is provided in the solder paste layer 14 mentioned above. By providing the metal mesh layer, the first TVS chip 1 and the second TVS chip 11 are less likely to be displaced due to vibration or temperature changes, thereby increasing the stability of the connection between the first TVS chip 1 and the second TVS chip 11.

[0018] In the aforementioned metal mesh layer, the longitude and latitude lines are arranged perpendicularly.

[0019] When using the above-mentioned bidirectional TVS protection device, the V-shaped notch on the pads allows the lead frame where the second pad is located to be firmly bonded to the connecting piece where the first pad is located and the insulating package. This prevents the lead frame and connecting piece from separating from their predetermined positions due to vibration and temperature changes, thus avoiding the TVS chip from separating from the lead frame or connecting piece. This increases the reliability of the bidirectional TVS protection device.

[0020] The above embodiments are only for illustrating the technical concept and features of this utility model, and are intended to enable those skilled in the art to understand the content of this utility model and implement it accordingly. They should not be construed as limiting the scope of protection of this utility model. All equivalent changes or modifications made in accordance with the spirit and essence of this utility model should be included within the scope of protection of this utility model.

Claims

1. A bidirectional TVS protection device, characterized in that: include: The components include a first TVS chip (1), a second TVS chip (11), a connector (2), a first lead frame (3), and a second lead frame (4). One end of the second lead frame (4) has a second pad (5), and the connector (2) has a first pad (12) near the end of the TVS chip. The second pad (5), the first TVS chip (1), the second TVS chip (11), and the connecting piece (2) are stacked at one end, and the cathode of the first TVS chip (1) and the cathode of the second TVS chip (11) are connected through the middle solder paste layer (14). The anode of the first TVS chip (1) is connected to the second pad (5) located below it through the lower solder paste layer (61), and the anode of the second TVS chip (11) is connected to the first pad (12) located above the connecting piece (2) through the upper solder paste layer (62). The other end of the connecting piece (2) is connected to one end of the first lead frame (3). The first lead frame (3) and the second lead frame (4) are respectively the negative pin (7) and the positive pin (8) of the TVS chip (1). The second pad (5) has a second V-shaped notch (91) at each of its four corners. The first TVS chip (1) is located in the central area of ​​the second pad (5), and the four second V-shaped notches (91) are located outside the central area of ​​the second pad (5). The first pad (12) has a first V-shaped notch (13) at each of its four corners. The second TVS chip (11) is located in the central area of ​​the first pad (12), and the four first V-shaped notches (13) are located outside the central area of ​​the first pad (12). An insulating package (10) covers the first TVS chip (1), the second TVS chip (11), the first pad (12), the second pad (5), and the first lead frame (3) and the second lead frame (4) near one end of the TVS chip (1).

2. The bidirectional TVS protection device according to claim 1, characterized in that: A metal mesh layer is provided inside the solder paste layer (14).

3. The bidirectional TVS protection device according to claim 2, characterized in that: In the metal mesh layer, the longitude and latitude lines are arranged perpendicularly.

4. The bidirectional TVS protection device according to claim 1, characterized in that: The negative electrode pin (7) extends from inside the insulating package (10). This negative electrode pin (7) consists of a negative electrode side pin portion located on the side wall of the insulating package (10) and a negative electrode bottom pin portion located at the bottom of the insulating package (10).

5. The bidirectional TVS protection device according to claim 1, characterized in that: The positive lead (8) extends from inside the insulating package (10). The positive lead (8) consists of a positive side lead portion located on the side wall of the insulating package (10) and a positive bottom lead portion located at the bottom of the insulating package (10).

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