High-power surface-mounted transient voltage protector

Abstract

The utility model provides a high-power surface-mounted transient voltage protector. The high-power surface-mounted transient voltage protector comprises a packaging main body, a chip body and a first electrode, the first electrode comprises a platform part and a lead part; the lead part is in a dovetail-like shape and comprises a convergent end and an open end; the convergence end of the lead part is connected with one end of the platform part; the chip body is arranged on the platform part; the packaging main body wraps the chip body and the platform part, and the open end of the lead part penetrates through the packaging main body to serve as a first external pin. The size of the chip body is improved to be rectangular, so that the effective area of the chip is increased to the maximum extent under the condition that the packaging size limitation is met, and the power performance of a product is improved; and meanwhile, the dovetail-like structure is adopted as the lead part, so that the stability between the lead part and the platform part is improved, the packaging stress is reduced, and the problems of product yield loss and poor reliability caused by the packaging stress are solved.

Description

Technical Field

[0001] The utility model relates to the technical field of semiconductor device packaging, in particular to a high-power surface mounted transient voltage protector. Background Art

[0002] As terminal products become increasingly miniaturized, users have more stringent requirements on electronic components such as TVS (Transient Voltage Suppressor), hoping that the unit power density of TVS components can be higher.

[0003] At present, TVS mainly adopts DO-214AB (SMD, Surface Mounted Devices) packaging. Among them, the power of SMD single-core products is mostly 3.0kW or less, and the power of dual-core products is basically 5kW or less, which cannot meet high power requirements. At the same time, because the product is limited by the package size, and according to the package size, the chip size in the package is also limited. For example, the chip used in DO-214AB products is square, and due to the influence of the package size, the upper limit size of the chip is about 160mil. When the chip size is further expanded, due to the influence of the package stress, the chip is prone to microcracks or cracks, and the product yield and reliability capabilities will be significantly reduced, which cannot meet market demand. Utility Model Content

[0004] The technical problem to be solved by the utility model is to provide a high-power surface-mount transient voltage protector to reduce the problems of product yield loss and poor reliability caused by packaging stress.

[0005] In order to solve the above technical problems, the technical solution adopted by the utility model is:

[0006] A high-power surface-mount transient voltage protector comprises a package body, a chip body and a first electrode; the first electrode comprises a platform portion and a lead portion; the lead portion is dovetail-shaped and comprises a convergent end and an open end; the convergent end of the lead portion is connected to one end of the platform portion; the chip body is arranged on the platform portion; the package body covers the chip body and the platform portion, and the open end of the lead portion passes through the package body as a first external pin.

[0007] Furthermore, a through hole is provided at the convergent end of the lead portion.

[0008] Furthermore, a boss is arranged at the center of the platform portion; and the chip body is arranged on the boss.

[0009] Furthermore, a gap is provided between the chip body and the boss.

[0010] Furthermore, a surface of the boss close to one side of the chip body is provided with bumps; the bumps are symmetrically arranged about the platform portion; the chip body is arranged on the bumps, and gaps are formed between the bumps.

[0011] Furthermore, a tin-fixing groove is provided on a surface of the boss close to one side of the chip body; and a gap is formed between the chip body and the tin-fixing groove.

[0012] Furthermore, grooves are provided on the upper surface and the lower surface of the lead portion.

[0013] Furthermore, it also includes a second electrode and a top electrode; the top electrode is connected to the side of the chip body away from the first electrode; one end of the second electrode is connected to the top electrode; the other end of the second electrode passes through the package body as a second external pin.

[0014] Furthermore, the second electrode is dovetail-shaped, and grooves are provided on the upper surface and the lower surface.

[0015] Furthermore, the chip body is rectangular.

[0016] The beneficial effects of the utility model are as follows: by improving the size of the chip body from a square to a rectangle under the existing DO-214AB product package size, the effective area of ​​the chip is increased to the maximum extent while meeting the package size limitations, thereby improving the product power performance and achieving a more effective transient voltage protection effect; at the same time, in order to reduce the stress problem caused by increasing the chip body size, the electrode structure of the product is optimized, a dovetail-shaped structure is used as the lead part, the stability between the lead part and the platform part is improved, and the package stress is reduced, thereby solving the stress problem caused by increasing the chip body size, and solving the product yield loss and poor reliability problems caused by the package stress. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a side view of a high-power surface mount transient voltage protector in an embodiment of the utility model;

[0018] Figure 2 It is a schematic diagram of the electrode structure of a high-power surface-mount transient voltage protector in an embodiment of the utility model;

[0019] Figure 3 A top view of an electrode structure of a high-power surface-mount transient voltage protector in an embodiment of the utility model;

[0020] Figure 4 It is a side view of the electrode structure of a high-power surface mount transient voltage protector in an embodiment of the utility model;

[0021] Figure 5 It is a schematic diagram of a boss structure of a high-power surface-mount transient voltage protector in an embodiment of the utility model;

[0022] Figure 6 It is a schematic diagram of another boss structure of a high-power surface-mount transient voltage protector in an embodiment of the utility model;

[0023] Description of labels:

[0024] 1. Package body; 2. Chip body; 21. Voltage protection chip; 3. First electrode; 31. Platform part; 311. Boss; 3111. Bump; 3112. Soldering bath; 32. Lead part; 321. Groove; 33. Through hole; 4. Second electrode; 5. Top electrode. DETAILED DESCRIPTION

[0025] In order to explain the technical content, achieved objectives and effects of the present invention in detail, the following is an explanation in conjunction with the implementation modes and the accompanying drawings.

[0026] Please refer to Figure 1 A high-power surface-mount transient voltage protector comprises a package body, a chip body and a first electrode; the first electrode comprises a platform portion and a lead portion; the lead portion is dovetail-shaped, comprising a convergent end and an open end; the convergent end of the lead portion is connected to one end of the platform portion; the chip body is arranged on the platform portion; the package body covers the chip body and the platform portion, and the open end of the lead portion passes through the package body as a first external pin.

[0027] From the above description, it can be seen that the beneficial effects of the utility model are: by improving the size of the chip body from a square to a rectangle under the existing DO-214AB product packaging size, the effective area of ​​the chip is maximized while meeting the limitations of the packaging size, thereby improving the product power performance and thus achieving a more effective transient voltage protection effect; at the same time, the electrode structure of the product is optimized, and a dovetail-shaped structure is used as the lead part, which improves the stability between the lead part and the platform part and reduces the packaging stress, thereby solving the problem of product yield loss and poor reliability caused by packaging stress.

[0028] Furthermore, a through hole is provided at the convergent end of the lead portion.

[0029] From the above description, it can be seen that by setting a through hole at the convergent end of the lead part, the package body fills the through hole position when the package body covers the chip body and the first electrode, thereby increasing the electrode fixation and locking the package body, and can improve the product's ability to prevent the intrusion of moisture or humidity.

[0030] Furthermore, a boss is arranged at the center of the platform portion; and the chip body is arranged on the boss portion.

[0031] From the above description, it can be seen that by setting a boss in the center of the platform part, when the chip body is set on the boss by solder, the excess solder around the chip body can be released, avoiding the product from being punctured or burned early due to the excess solder around in subsequent applications.

[0032] Furthermore, a gap is provided between the chip body and the boss.

[0033] In one embodiment, a surface of the boss close to one side of the chip body is provided with bumps; the bumps are symmetrically arranged about the platform portion; the chip body is arranged on the bumps, and gaps are formed between the bumps.

[0034] In another embodiment, a tin-fixing groove is provided on a surface of the boss close to the chip body; and a gap is formed between the chip body and the tin-fixing groove.

[0035] From the above description, it can be seen that by setting structures such as bumps or tin-fixing grooves on the bosses, a gap is formed between the chip body and the bosses, and the gap formed can fix and maintain the thickness of the solder, thereby avoiding the problem of random failure of electrical performance of the product due to structural stress during the subsequent reflow soldering of the PCB board.

[0036] Furthermore, grooves are provided on the upper surface and the lower surface of the lead portion.

[0037] From the above description, it can be seen that by providing grooves on both the upper surface and the lower surface of the lead part, the grooves can increase the effect of fixing the electrodes and locking the package body, thereby improving the product's ability to prevent the intrusion of moisture and humidity.

[0038] Furthermore, it also includes a second electrode and a top electrode; the top electrode is connected to the side of the chip body away from the first electrode; one end of the second electrode is connected to the top electrode; the other end of the second electrode passes through the package body as a second external pin.

[0039] It can be seen from the above description that by providing the second electrode and the top electrode, the positive and negative pins of the product can be led out.

[0040] Furthermore, the second electrode is dovetail-shaped, and grooves are provided on the upper surface and the lower surface.

[0041] It can be seen from the above description that the second electrode also adopts a dovetail-like shape, and grooves are provided on its upper surface and lower surface, thereby reducing the stress of the second electrode and improving its connection stability.

[0042] Furthermore, the chip body is rectangular.

[0043] From the above description, it can be seen that by changing the chip body from a traditional square design to a rectangular design, the effective area of ​​the chip is maximized while meeting the size limitations of the existing DO-214AB product package, thereby improving the product power performance.

[0044] The high-power surface mount transient voltage protector provided by the utility model can be applied to DO-214AB package products, which can meet the power requirements of the products and solve the problems of product yield loss and poor reliability caused by assembly stress. The following is an explanation through specific implementation methods:

[0045] Embodiment 1

[0046] Please refer to Figures 1 to 3 A high-power surface-mount transient voltage protector comprises a package body 1, a chip body 2, a first electrode 3, a second electrode 4 and a top electrode 5; the first electrode 3 comprises a platform portion 31 and a lead portion 32; the lead portion 32 is dovetail-shaped, comprising a convergent end and an open end; the convergent end of the lead portion 32 is connected to one end of the platform portion 31; the chip body 2 is arranged on the platform portion 31; the package body 1 covers the chip body 2 and the platform portion 31, and the open end of the lead portion 32 passes through the package body 1 as a first external pin; the top electrode 5 is connected to a side of the chip body 2 away from the first electrode 3; one end of the second electrode 4 is connected to the top electrode 5; the other end of the second electrode 4 passes through the package body 1 as a second external pin; wherein the package body 1 is injection molded using a thermosetting epoxy resin (black or white), and the first electrode 3 and the second electrode 4 need to be assembled and cut and bent A specific pin structure is formed; the chip body 2 includes at least two stacked voltage protection chips 21; the voltage protection chip 21 is a similar chip such as a silicon-based semiconductor voltage protection device or other similar chips; different from the traditional square chip (length × width: 4.064x4.064mm), the chip length in this embodiment can reach 4.7244mm and above, and the width can reach 4.0132mm and above, for example, a rectangular chip design of length × width × height: 8.2x6.3x2.8mm is adopted, with a unique electrode design, because the package size remains unchanged, when the width is fixed, the chip length is increased to form a rectangle, thereby increasing the chip area, which can improve the power performance of existing DO-214AB (SMD) products, and the power of single-chip products can be increased from 3kW to 5kW, and the power of dual-core products can be increased from 5kW to 8-10kW. Of course, the chip body 2 can also be other shapes such as square and round.

[0047] Please refer to Figures 2 to 4The convergent end of the lead portion 32 of the first electrode 3 is provided with a through hole 33; similarly, the second electrode 4 may also be provided with a through hole 33 as required; Figure 3 As shown, a racetrack-shaped through hole 33 is provided on the dovetail structure, and the shape of the through hole 33 can be adjusted according to the length and width of the dovetail structure, such as being set to an elliptical shape, etc., which has the purpose of increasing electrode fixation and locking epoxy resin, improving the ability to prevent moisture or humidity from intruding, and playing a positive role in the high reliability of the product;

[0048] In an optional embodiment, the upper surface and the lower surface of the lead portion 32 are both provided with grooves 321; similarly, the upper surface and the lower surface of the second electrode 4 are both provided with grooves 321; Figure 4 As shown, the groove 321 is a "V"-shaped structure, which serves to increase the electrode fixation and lock the epoxy resin, and improve the ability to prevent the intrusion of moisture or humidity.

[0049] Please refer to Figure 4 A boss 311 is provided at the center of the platform portion 31 of the first electrode 3; the chip body 2 is provided on the boss 311, that is, the boss 311 is directly connected to the chip body 2 through solder; wherein, the design requirement of the boss 311 is to generate less stress on the chip; the boss 311 can release the excess solder around the chip body 2 to avoid the product in subsequent applications, especially when the surge current is too large, the chip will be prematurely broken down or burned due to the excess solder around it, and at the same time, it has the function of fixing and maintaining the solder thickness; at the same time, the general solder design thickness needs to reach more than 10um to avoid the problem of random failure of electrical performance due to structural stress in the subsequent reflow soldering of the PCB board; and the boss 311 can be adjusted in size according to the size of the chip body 2, and its shape can be a square, rectangular, circular or other shaped platform.

[0050] In a preferred embodiment, a gap is provided between the chip body 2 and the boss 311;

[0051] Please refer to Figure 5 In an optional embodiment, a bump 3111 is provided on the surface of the boss 311 close to the chip body 2; and the chip body 2 is disposed on the bump 3111, so that a gap is formed between the chip body 2 and the boss 311 through the bump 3111; Figure 5 As shown, the bumps 3111 are symmetrically arranged about the platform portion 31, and play an effective supporting role for the chip body 2; wherein, the shape of the bumps 3111 can be circular, square, or the like.

[0052] Please refer to Figure 6In another optional embodiment, a tin-fixing groove 3112 is provided on the surface of the boss 311 close to the chip body 2, and when the chip body 2 is placed on the boss 311, a gap is formed between the chip body 2 and the tin-fixing groove 3112; Figure 6 As shown, the tin-fixing groove 3112 is a cross V-shaped groove 321; the number, shape and setting direction of the tin-fixing groove 3112 can be adjusted according to actual conditions, for example, it can also be set to a "well" shaped structure, etc. At the same time, the description of the position, shape, number, size, etc. of the structure in this example should not be interpreted as being limited to the embodiments described herein.

[0053] In summary, the high-power surface mount transient voltage protector provided by the utility model improves the product chip size from square to rectangular under the existing DO-214AB (SMD) product package size, maximizes the effective chip area while meeting the package size limitation, and optimizes the design of the frame and jumper used in conjunction with the product, thereby improving the power performance of the existing DO-214AB (SMD) product, and the power of the single-chip product can be increased from 3kW to 5kW, and the power of the dual-core product can be increased from 5kW to 8-10kW; at the same time, the product structure is optimized, and a dovetail structure for stress release, a "V"-shaped groove structure, and a specially designed platform for improving solder overflow and solder thickness are designed to meet the product power requirements and solve the stress problem caused by increasing the chip body size and the product yield loss caused by assembly stress, as well as the problem of poor reliability; at the same time, the package structure adopts high-reliability thermosetting epoxy resin in combination with a mature injection molding process, and has a long service life and high reliability.

[0054] The above description is only an embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent transformations made using the contents of the specification and drawings of the present invention, or directly or indirectly applied in the relevant technical field, are also included in the patent protection scope of the present invention.

Claims

1. A high power surface mount transient voltage protector, characterized in that: It includes a packaging body, a chip body and a first electrode; The first electrode includes a platform portion and a lead portion; The lead portion is dovetail-shaped and includes a convergent end and an open end; The convergent end of the lead portion is connected to one end of the platform portion; The chip body is arranged on the platform portion; The package body covers the chip body and the platform portion, and the open end of the lead portion passes through the package body as a first external pin.

2. A high power surface mount transient voltage protector according to claim 1, characterized in that: The convergent end of the lead portion is provided with a through hole.

3. A high power surface mount transient voltage protector according to claim 1, characterized in that: A boss is provided at the center of the platform portion; The chip body is arranged on the boss.

4. A high power surface mount transient voltage protector according to claim 3, characterized in that: A gap is arranged between the chip body and the boss.

5. A high power surface mount transient voltage protector according to claim 4, characterized in that: The surface of the boss close to the chip body is provided with a convex point; The protrusions are symmetrically arranged about the platform portion; The chip body is arranged on the bumps, and gaps are formed between the bumps.

6. A high power surface mount transient voltage protector according to claim 4, characterized in that: A tin-fixing groove is provided on the surface of the boss close to the chip body; A gap is formed between the chip body and the tin-fixing bath.

7. The high power surface mount transient voltage protector according to claim 1, characterized in that: The upper surface and the lower surface of the lead part are both provided with grooves.

8. The high power surface mount transient voltage protector according to claim 1, characterized in that: Also comprising a second electrode and a top electrode; The top electrode is connected to a side of the chip body away from the first electrode; One end of the second electrode is connected to the top electrode; The other end of the second electrode passes through the package body as a second external pin.

9. A high power surface mount transient voltage protector according to claim 8, characterized in that: The second electrode is dovetail-shaped, and grooves are arranged on the upper surface and the lower surface.

10. The high power surface mount transient voltage protector according to claim 1, characterized in that: The chip body is rectangular.

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