A super-power TVS diode for vehicle

Abstract

The utility model discloses a kind of vehicle superpower TVS diodes, belong to press-fit vehicle superpower DO-218AB package, TVS diode product design and packaging field. The diode includes fin, lower soldering sheet, lower chip, middle soldering sheet, upper chip, upper soldering sheet, connecting sheet, terminal, small soldering sheet, each component is arranged and welded fixed by specific mode, polyimide is applied to the periphery of chip, and epoxy resin is plastic-encapsulated outside. The utility model uses chip lamination design, improves the power of TVS diode under the condition of not increasing chip size, reduces stress in production process, reduces reverse leakage current, and PN junction is protected by polyimide, improves the reliability of product, and is suitable for automobile circuit protection field.

Description

Technical Field

[0001] This utility model relates to the field of TVS diode technology, specifically to an ultra-high power TVS diode for automotive applications. Background Technology

[0002] High-power TVS diodes in DO-218AB packages are core automotive components, specifically designed for automotive circuit protection. They are semiconductor devices designed to withstand damage to sensitive electronic components from transient voltages such as surges, ESD, and inductive load switching. They are suitable for the circuit systems of new energy vehicles and the 12V / 24V network protection of traditional vehicles. With the development of automotive electrification, connectivity, intelligence, and sharing, customers have increasingly higher power requirements for automotive power components. For the ultra-high power TVS diodes required by customers, the industry currently mainly uses glass passivation technology or planar technology to increase the chip size and thus increase the power of the component by increasing the chip area.

[0003] Currently, the industry primarily uses glass passivation technology or planar technology chips for ultra-high power TVS diodes, increasing the chip size to improve the device's power. However, this approach has several drawbacks: the DO-218AB main package size is fixed, limiting the range for increasing chip size; when the chip size approaches the main package size, there is a risk of side leakage, leading to poor appearance and reliability; the larger the chip size, the greater the stress generated during manufacturing processes such as high-temperature welding, molding, and lead bending, significantly impacting the product's electrical properties and reliability, easily leading to poor electrical performance and premature failure; larger chip sizes increase the probability of surface defects and impurities, resulting in increased reverse leakage current, especially noticeable at high temperatures, affecting product reliability; and due to the characteristics of the PN junction protection material, glass passivation or planar technology chips are prone to brittleness during packaging and use, leading to premature failure. Utility Model Content

[0004] This invention provides an ultra-high power TVS diode for automotive applications to solve a series of problems caused by increasing the chip size to improve power when the DO-218AB package size is fixed. It achieves power improvement without increasing chip size, while reducing stress, reducing reverse leakage current, and improving reliability.

[0005] To solve the above-mentioned technical problems, the technical solution provided by this utility model is as follows:

[0006] A high-power TVS diode for automotive applications includes a heat sink, on which a lower solder pad, a lower chip, a middle solder pad, an upper chip, an upper solder pad, and a connecting piece are stacked sequentially upwards.

[0007] A terminal is installed on one side of the connecting piece;

[0008] Small solder pads are installed between the terminals and connecting pieces. The components are fixed by a fixture, and the components are welded together using a vacuum furnace. Finally, epoxy resin is used to seal the components to form the upper shell.

[0009] Preferably, the outer surfaces of the lower and upper chips are coated with polyimide.

[0010] Preferably, a groove is formed at the upper end of the terminal to accommodate a small solder pad.

[0011] Preferably, the side of the terminal away from the connecting piece has a bent structure.

[0012] Preferably, the lower chip and the upper chip are the same size, and both are smaller than the main body size of the package.

[0013] Preferably, the size of the middle solder pad is adapted to the lower chip and the upper chip.

[0014] With the above structure, this utility model has the following advantages:

[0015] Employing a chip stacking design, the power of the TVS diode is increased without increasing chip size, meeting customer demand for ultra-high power components above 15KW. It avoids the risk of side leakage caused by chip size being close to the package body size, ensuring product appearance and reliability. It reduces stress on the product caused by welding and molding processes during production, lowering the probability of electrical defects and early failure. It reduces reverse leakage current, especially at high temperatures, improving product reliability. The use of polyimide to protect the chip's PN junction provides excellent protection and high reliability during packaging and use.

[0016] The above overview is for illustrative purposes only and is not intended to be limiting in any way. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features of the present invention will become readily apparent from the accompanying drawings and the following detailed description. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the structure of this utility model.

[0019] Figure 2 This is an exploded view of this utility model.

[0020] Figure 3 This is a schematic diagram of the structure of this utility model before packaging.

[0021] As shown in the figure: 1. Heat sink; 2. Lower solder pad; 3. Lower chip; 4. Middle solder pad; 5. Upper chip; 6. Upper solder pad; 7. Connecting piece; 8. Terminal; 9. Small solder pad; 10. Polyimide; 11. Upper housing; 12. Groove. Detailed Implementation

[0022] The embodiments of this application are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0023] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0024] The present invention will now be described in further detail in conjunction with the full text.

[0025] Combined with appendix Figures 1-3 A high-power TVS diode for automotive applications includes a heat sink 1, on which a lower solder pad 2, a lower chip 3, a middle solder pad 4, an upper chip 5, an upper solder pad 6, and a connecting piece 7 are stacked sequentially upwards. Using this method can improve the diode power, reduce stress caused during production, reduce reverse leakage current, improve product yield and reliability, and enable the product to meet customers' application requirements for high-power components.

[0026] A terminal 8 is installed on one side of the connecting piece 7;

[0027] A small solder pad 9 is installed between the terminal 8 and the connecting piece 7. All components are fixed by a fixture, and the components are welded together using a vacuum furnace. The upper shell 11 is formed by encapsulation with epoxy resin.

[0028] The outer surfaces of the lower chip 3 and the upper chip 5 are coated with polyimide 10.

[0029] A groove 12 is provided at the upper end of terminal 8 to accommodate small solder pads 9.

[0030] The side of terminal 8 away from connecting piece 7 has a bent structure.

[0031] The lower chip 3 and the upper chip 5 are the same size, and both are smaller than the main body size of the package.

[0032] The size of the middle solder pad 4 is compatible with the lower chip 3 and the upper chip 5.

[0033] This invention uses a chip stacking method to increase the power of the DO-218AB TVS diode and uses polyimide to protect the PN junction of the chip, meeting customers' needs for ultra-high power components with a power of up to 15KW or more.

[0034] Increase the power of components using a chip stacking design without increasing chip size.

[0035] Without increasing the chip size, there is no risk of poor appearance and reliability due to chip leakage on the side.

[0036] Reduce stress during the production process and improve product reliability.

[0037] Compared to large-size chips, this reduces reverse leakage current and improves product reliability.

[0038] Using polyimide to protect the PN junction provides good protection and high reliability during packaging and use.

[0039] In specific implementation, this utility model

[0040] The chip-stacking automotive high-power TVS diode provided in this embodiment is assembled as follows: First, the lower solder pad 2 is placed on the heat sink 1, and then the lower chip 3, middle solder pad 4, upper chip 5, and upper solder pad 6 are placed in sequence. The small solder pad 9 is placed in the groove 12 at the terminal 8, and then the connecting piece 7 is placed. After all the components are fixed by a special fixture, they are placed in a vacuum furnace for welding to connect the components into a whole. After welding, polyimide 10 is applied around the lower chip 3 and the upper chip 5. Finally, epoxy resin is used for encapsulation to form the upper shell 11, completing the final product.

[0041] The present invention and its embodiments have been described above. This description is not restrictive, and the embodiments shown throughout the text are only one of the embodiments of the present invention. The actual structure is not limited to this. In conclusion, if a person skilled in the art is inspired by this description and designs a similar structure and embodiment without departing from the inventive spirit of the present invention, such design should fall within the protection scope of the present invention.

Claims

1. A vehicle use super power TVS diode, characterized by, It includes a heat sink (1), on which a lower solder pad (2), a lower chip (3), a middle solder pad (4), an upper chip (5), an upper solder pad (6), and a connecting piece (7) are stacked in sequence upwards; A terminal (8) is installed on one side of the connecting piece (7); Small solder pads (9) are installed between the terminal (8) and the connecting piece (7). The components are fixed by a fixture, and the components are welded together using a vacuum furnace. The upper shell (11) is formed by encapsulation with epoxy resin.

2. The super power TVS diode for vehicle of claim 1, wherein: The outer surfaces of the lower chip (3) and the upper chip (5) are coated with polyimide (10).

3. The super power TVS diode for vehicle of claim 1, wherein: The upper end of the terminal (8) has a groove (12) for use with a small solder pad (9).

4. The super power TVS diode for vehicle of claim 1, wherein: The side of the terminal (8) away from the connecting piece (7) has a bent structure.

5. The super power TVS diode for vehicle of claim 1, wherein: The lower chip (3) and the upper chip (5) are the same size, and both are smaller than the main body size of the package.

6. The super-power TVS diode for vehicle of claim 1, wherein: The size of the middle solder pad (4) is adapted to the lower chip (3) and the upper chip (5).

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