Silicon carbide enhanced field effect transistor

Abstract

The utility model discloses a silicon carbide enhanced field effect transistor, and belongs to the technical field of semiconductor packaging. A silicon carbide enhanced field effect transistor comprises a plastic package body, a mounting groove, a deformation groove, a waterproof groove, a substrate, a chip, a pin, a cooling fin and an extrusion block. The plastic package body is usually made of epoxy resin, and the chip is welded in the middle of the substrate through solder paste. In order to improve the sealing performance of the field effect transistor, the annular protrusion is formed on the periphery of the substrate through the stamping technology, and the waterproof groove matched with the annular protrusion is formed in the plastic package body, so that the compactness of connection between the substrate and the plastic package body is improved, water is prevented from entering components, and the effect of protecting the components is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor packaging, and more specifically, to a silicon carbide enhanced field effect transistor. Background Art

[0002] Silicon carbide enhanced field effect transistor is a metal oxide semiconductor field effect transistor that uses silicon carbide as the semiconductor material. It can be driven under high-frequency conditions where IGBTs cannot work, thereby achieving the miniaturization of passive devices and is suitable for high-frequency circuit applications. Silicon carbide field effect transistors can reduce switching losses and achieve miniaturization of heat dissipation components. They have better high-temperature resistance and are more reliable under high-temperature conditions.

[0003] When packaging a silicon carbide enhanced field effect transistor, it is necessary to consider the heat dissipation effect and waterproofness of the package. The existing patent document with publication number CN108766947B provides a silicon carbide enhanced field effect transistor, which provides a heat sink on the lower surface of the chip substrate. The integrated setting of the heat sink eliminates the need to install a heat sink in subsequent use, saves installation procedures and is convenient to use.

[0004] The above method achieves the purpose of increasing the heat dissipation effect of the MOS tube by adding a heat sink to the plastic package body. However, there is a difference in the thermal expansion coefficient between the material used as the heat sink and the material of the plastic package body, which causes the thermal deformation of the heat sink and the plastic package body to be out of sync. When the MOS tube works at a high temperature, the contact interface between the heat sink and the plastic package body will peel off, thereby reducing the heat transfer efficiency between the heat sink and the plastic package body, resulting in a reduction in the heat dissipation effect.

[0005] Although the device has many beneficial effects, the following problems still exist:

[0006] In view of this, we propose a silicon carbide enhanced field effect transistor. Summary of the invention

[0007] 1. Technical issues to be solved

[0008] The object of the present invention is to provide a silicon carbide enhanced field effect transistor to solve the problems raised in the above background technology.

[0009] 2. Technical solution

[0010] The present invention is achieved through the following technical solutions:

[0011] A silicon carbide enhanced field effect transistor, comprising a plastic package, a substrate, a chip, a pin, and a heat sink;

[0012] The substrate is encapsulated in a plastic package, the chip is welded on the substrate, and the pins are connected and fixed to the plastic package;

[0013] The surface of the heat sink is arranged in an up-and-down undulating shape;

[0014] A plurality of mounting grooves are provided on the back side of the plastic package body, and the heat sink is inserted into the mounting grooves;

[0015] Both sides of the installation groove are provided with deformation grooves opened on the back side of the plastic sealing body;

[0016] An extrusion block is inserted into the deformation groove.

[0017] As an optional solution of the technical solution of this application document, the bottom size of the installation groove is larger than the upper size.

[0018] As an optional solution of the technical solution of this application document, the depth of the deformation groove is greater than the depth of the installation groove.

[0019] As an optional solution of the technical solution of the present application document, the depth of the extrusion block inserted into the deformation groove is less than the depth of the installation groove.

[0020] As an optional solution of the technical solution of the present application document, the extrusion block is made of silicone rubber material, and the extrusion block is fixedly arranged on the heat sink.

[0021] As an optional solution of the technical solution of this application document, the bottom size of the deformation groove is smaller than the upper size.

[0022] As an optional solution of the technical solution of the present application document, a waterproof groove is opened inside the plastic packaging body, and the substrate is inserted into the waterproof groove.

[0023] 3. Beneficial effects

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1. The present application sets a heat sink on the back side of the plastic package body, and utilizes the structural feature of ups and downs to increase the heat dissipation efficiency of the heat sink; the heat sink can be stably installed inside the mounting groove by virtue of the structural feature that the bottom size of the mounting groove is larger than the external size.

[0026] 2. The present application sets a deformation groove on the back side of the plastic package body and inserts an extrusion block inside the deformation groove. When the field effect tube is in a high-temperature working environment, the extrusion block produces thermal deformation, and the internal stress acts on the heat sink through the side wall of the installation groove, thereby increasing the effective contact area between the heat sink and the plastic package body, suppressing the interface peeling phenomenon caused by the different thermal expansion coefficients between the heat sink and the plastic package body, and increasing the heat dissipation effect of the field effect tube.

[0027] 3. The present application can increase the tightness of the connection between the substrate and the plastic package body by opening a waterproof groove in the plastic package body, prevent moisture from entering the interior of the components, and play a role in protecting the components. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of the internal structure of a silicon carbide enhanced field effect transistor;

[0029] Figure 2 This is a rear view of a silicon carbide enhanced field effect transistor;

[0030] Figure 3 It is a schematic diagram of the heat sink installation structure of a silicon carbide enhanced field effect tube;

[0031] In the figure: 1, plastic package body; 101, mounting groove; 102, deformation groove; 103, waterproof groove; 2, substrate; 3, chip; 4, pin; 5, heat sink; 501, extrusion block. DETAILED DESCRIPTION

[0032] The technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings.

[0033] Please refer to the figure, the present invention provides a technical solution:

[0034] A silicon carbide enhanced field effect transistor comprises a plastic package 1, a mounting groove 101, a deformation groove 102, a waterproof groove 103, a substrate 2, a chip 3, a pin 4, a heat sink 5, and an extrusion block 501.

[0035] The plastic package body 1 is usually made of epoxy resin, and the chip 3 is soldered to the middle of the substrate 2 by solder paste; in order to increase the sealing performance of the field effect tube, a stamping process is used to form an annular protrusion on the periphery of the substrate 2, and a waterproof groove 103 adapted to the annular protrusion is opened in the plastic package body 1 to increase the tightness of the connection between the substrate 2 and the plastic package body 1, prevent moisture from entering the interior of the component, and play a role in protecting the device.

[0036] In order to increase the heat dissipation effect of the field effect tube, a plurality of mounting grooves 101 are opened on the back side of the plastic package body 1, and the bottom size of the mounting groove 101 is larger than the upper size; the heat sink 5 is arranged to be undulating up and down to increase the surface area of ​​the heat sink 5 and improve the heat dissipation effect; the heat sink 5 is inserted into the mounting groove 101, and the heat sink 5 is fixed by utilizing the structural feature that the bottom size of the mounting groove 101 is larger than the upper size.

[0037] Deformation grooves 102 are provided on both sides of the installation groove 101 and are opened on the back side of the plastic package body 1. The depth of the deformation groove 102 is less than the depth of the installation groove 101, and an extrusion block 501 fixed on the heat sink 5 is inserted into the deformation groove 102. The depth of the deformation groove 102 is less than the depth of the installation groove 101, and the extrusion block 501 is made of silicone rubber.

[0038] The plastic package body 1 is made of epoxy resin, and the thermal expansion coefficient is between (50-70)×10^-6 / ℃; the heat sink 5 is made of aluminum alloy, and the thermal expansion coefficient is between (24-24)×10^-6 / ℃; the extrusion block 501 is made of silicone rubber, and the thermal expansion coefficient is on the order of 10^-4 / ℃; in a high-temperature working environment, the silicone rubber expands at the upper part of the deformation groove 102, pushing the inner wall of the installation groove 101 to both sides, and the inner wall of the installation groove 101 acts on the heat sink 5, which can play a role of squeezing the heat sink 5 downward, thereby increasing the positive stress of the contact surface between the heat sink 5 and the plastic package body 1, and reducing the interface peeling between the heat sink 5 and the plastic package body 1 due to the difference in thermal expansion coefficients, resulting in a decrease in the heat dissipation effect.

[0039] The gap between the deformation groove 102 and the extrusion block 501 provides space for the extrusion block 501 and the plastic package body 1 to deform thermally, which can effectively reduce the thermal stress inside the plastic package body 1 and increase the service life of the device.

Claims

1. A silicon carbide enhanced field effect transistor, characterized in that: It comprises a plastic package (1), a substrate (2), a chip (3), pins (4), and a heat sink (5); The substrate (2) is encapsulated in a plastic package (1), the chip (3) is welded on the substrate (2), and the pin (4) is connected and fixed to the plastic package (1); The surface of the heat sink (5) is arranged in an up-and-down undulating shape; The back side of the plastic package body (1) is provided with a plurality of mounting grooves (101), and the heat sink (5) is inserted into the mounting grooves (101); Both sides of the installation groove (101) are provided with deformation grooves (102) opened on the back side of the plastic packaging body (1); An extrusion block (501) is inserted into the deformation groove (102).

2. The silicon carbide enhanced field effect transistor according to claim 1, characterized in that: The bottom dimension of the installation groove (101) is larger than the upper dimension.

3. The silicon carbide enhanced field effect transistor according to claim 1, characterized in that: The depth of the deformation groove (102) is greater than the depth of the installation groove (101).

4. The silicon carbide enhanced field effect transistor according to claim 1, characterized in that: The depth of the extrusion block (501) inserted into the deformation groove (102) is less than the depth of the installation groove (101).

5. The silicon carbide enhanced field effect transistor according to claim 1, characterized in that: The extrusion block (501) is made of a silicone rubber material and is fixedly arranged on the heat sink (5).

6. The silicon carbide enhanced field effect transistor according to claim 1, characterized in that: The bottom dimension of the deformation groove (102) is smaller than the upper dimension.

7. The silicon carbide enhanced field effect transistor according to claim 1, characterized in that: A waterproof groove (103) is provided inside the plastic packaging body (1), and the substrate (2) is inserted into the waterproof groove (103).

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