A heat dissipation ceramic packaging structure for SiC power devices

Abstract

The present invention relates to the field of semiconductor technology, specifically to a SiC power device heat dissipation ceramic packaging structure, including a substrate, a silicon carbide device and a ceramic package, the left and right inner walls of the ceramic package are fixed with a plurality of heat conducting plates, the end surface of the heat conducting plate away from the ceramic package is fixed with a wavy heat conducting sheet, the lower surface of the convex part of the wavy heat conducting sheet abuts the upper surface of the silicon carbide device, and the lower surface of the concave part of the wavy heat conducting sheet is fixed with a plurality of I-type heat conducting sheets arranged in parallel at equal intervals on the left and right, the bottom end of the I-type heat conducting sheet is fixed with an S-type heat conducting sheet, and the bottom end of the S-type heat conducting sheet is fixed with an L-type heat conducting sheet. The present invention can clamp the silicon carbide device together with the substrate through the heat conducting plate, the wavy heat conducting sheet, the I-type heat conducting sheet, the S-type heat conducting sheet and the L-type heat conducting sheet, and is connected to the ceramic package through the heat conducting sheet to construct an efficient heat conduction and heat dissipation channel.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and in particular to a heat dissipation ceramic packaging structure for a SiC power device. Background Art

[0002] Silicon carbide (SiC) has the advantages of wide bandwidth, strong critical breakdown field, high thermal conductivity, high voltage, high temperature, and high frequency. The traditional packaging method used for silicon-based devices has large parasitic inductance parameters, which is difficult to match the fast switching characteristics of SiC devices. At the same time, the packaging reliability is greatly reduced under high temperature conditions. In order to give full play to the advantages of SiC devices, it is necessary to improve the existing packaging technology. Summary of the invention

[0003] The object of the present invention is to provide a SiC power device heat dissipation type ceramic packaging structure to solve the problems raised in the above background technology.

[0004] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a SiC power device heat dissipation ceramic packaging structure, comprising a substrate and a silicon carbide device, a ceramic package is fixedly provided on the upper surface of the substrate and located outside the silicon carbide device, the upper surface of the substrate abuts the lower surface of the silicon carbide device, a plurality of heat conducting plates are fixedly provided on the left and right inner walls of the ceramic package, and the plurality of heat conducting plates are arranged at equal intervals in the front-to-back direction, a wavy heat conducting sheet is fixedly provided on the end surface of the heat conducting plate away from the ceramic package, the lower surface of the convex part of the wavy heat conducting sheet abuts the upper surface of the silicon carbide device, and a plurality of I-type heat conducting sheets arranged in parallel at equal intervals on the left and right are fixedly provided on the lower surface of the concave part of the wavy heat conducting sheet, an S-type heat conducting sheet is fixedly provided at the bottom end of the I-type heat conducting sheet, and an L-type heat conducting sheet is fixedly provided at the bottom end of the S-type heat conducting sheet and located above the silicon carbide device.

[0005] Optionally, an annular gap is provided between the outer wall of the silicon carbide device and the inner wall of the ceramic package, a terminal is fixedly provided on the upper surface of the silicon carbide device, the upper surface of the terminal is fixedly passed through the upper surface of the ceramic package, and the two wavy heat conductive plates are located on the left and right sides of the terminal.

[0006] Optionally, the left and right side walls of the ceramic package are integrally formed with chamfered surfaces, the inner walls of the chamfered surfaces are fixedly connected to the heat conducting plate, the outer walls of the chamfered surfaces are fixedly provided with a heat sink, and the chamfered surfaces are provided with a through hole extending upward and downward, and a heat conducting column passing through the through hole is fixedly provided between the heat sink and the heat conducting plate.

[0007] Optionally, a plurality of inverted conical holes are opened on the lower surface of the L-shaped thermal conductive sheet, and the plurality of inverted conical holes are evenly distributed in a matrix manner. A single-component room-temperature curing thermal conductive silicone is coated between the lower surface of the L-shaped thermal conductive sheet and the upper surface of the silicon carbide device. The length of the single-component room-temperature curing thermal conductive silicone extending into the inverted conical hole is less than the depth of the inverted conical hole.

[0008] Optionally, the heat conducting plate and the wave-shaped heat conducting sheet are integrally formed, and the I-shaped heat conducting sheet, the S-shaped heat conducting sheet and the L-shaped heat conducting sheet are integrally formed.

[0009] Optionally, the heat conducting plate is an aluminum sheet or a copper sheet, and the I-type heat conducting sheet is an aluminum sheet coated with a graphene film or a copper sheet coated with a graphene film.

[0010] Compared with the prior art, the present invention has the following beneficial effects:

[0011] 1. The present invention can clamp the silicon carbide device together with the substrate through the heat conductive plate, the wave-shaped heat conductive sheet, the I-shaped heat conductive sheet, the S-shaped heat conductive sheet and the L-shaped heat conductive sheet, and connect the heat conductive sheet with the ceramic package to construct an efficient heat conduction and heat dissipation channel;

[0012] 2. In the present invention, the air in the inverted cone hole provides moisture for the curing of the single-component room-temperature curing thermally conductive silicone to produce a chemical reaction, thereby achieving condensation curing. The cured single-component room-temperature curing thermally conductive silicone forms an inverted cone block in the inverted cone hole, and a snap connection is formed between the inverted cone block and the lower surface of the L-shaped thermal conductive sheet, so that the L-shaped thermal conductive sheet can stably adsorb the silicon carbide device. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a front view of the present invention;

[0014] Figure 2 It is a left partial cross-sectional view of the present invention;

[0015] Figure 3 It is a schematic diagram of the structures of the heat conducting plate, the wave-shaped heat conducting sheet, the I-shaped heat conducting sheet, the S-shaped heat conducting sheet and the L-shaped heat conducting sheet in the present invention;

[0016] Figure 4 for Figure 2 Schematic diagram of the structure with the A part in the middle enlarged.

[0017] In the figure: 1. substrate; 2. silicon carbide device; 3. ceramic package; 4. heat conducting plate; 5. wavy heat conducting sheet; 6. I-type heat conducting sheet; 7. S-type heat conducting sheet; 8. L-type heat conducting sheet; 9. terminal; 10. chamfered surface; 11. heat sink; 12. thermal conductive column; 13. through hole; 14. inverted tapered hole. DETAILED DESCRIPTION

[0018] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0019] Example: See Figures 1 to 4 The present invention provides a SiC power device heat dissipation ceramic packaging structure, including a substrate 1 and a silicon carbide device 2. A ceramic package 3 is fixedly provided on the upper surface of the substrate 1 and located outside the silicon carbide device 2. The ceramic package 3 is silicon carbide ceramic. The upper surface of the substrate 1 abuts against the lower surface of the silicon carbide device 2. An annular gap is provided between the outer side wall of the silicon carbide device 2 and the inner side wall of the ceramic package 3. A terminal 9 is fixedly provided on the upper surface of the silicon carbide device 2. The upper surface of the terminal 9 is fixedly passed through the upper surface of the ceramic package 3.

[0020] A plurality of heat conducting plates 4 are fixedly provided on the left and right inner walls of the ceramic package 3. The left and right side walls of the ceramic package 3 are integrally formed with chamfered surfaces 10. The inner walls of the chamfered surfaces 10 are fixedly connected to the heat conducting plates 4. The outer walls of the chamfered surfaces 10 are fixedly provided with heat sinks 11. The chamfered surfaces 10 are provided with through holes 13 extending upward and downward. A heat conducting column 12 extending through the through holes 13 is fixedly provided between the heat sink 11 and the heat conducting plates 4.

[0021] In addition to the above-mentioned embodiment, in this embodiment, a plurality of heat conducting plates 4 are arranged at equal intervals in the front-to-back direction, and a wave-shaped heat conducting sheet 5 is fixedly provided on the end surface of the heat conducting plate 4 away from the ceramic package 3, and two wave-shaped heat conducting sheets 5 are located on the left and right sides of the terminal 9. The lower surface of the convex part of the wave-shaped heat conducting sheet 5 abuts against the upper surface of the silicon carbide device 2, and the lower surface of the concave part of the wave-shaped heat conducting sheet 5 is fixedly provided with a plurality of I-shaped heat conducting sheets 6 arranged in parallel at equal intervals on the left and right, and an S-shaped heat conducting sheet 7 is fixedly provided at the bottom end of the I-shaped heat conducting sheet 6, and an L-shaped heat conducting sheet 8 is fixedly provided at the bottom end of the S-shaped heat conducting sheet 7 and located above the silicon carbide device 2. The wave-shaped heat conducting sheet 5 has a certain elasticity, and the wave-shaped heat conducting sheet 5 and the substrate 1 can clamp the silicon carbide device 2 together. The S-shaped thermal conductive sheet 7 also has a certain elasticity and can be compressed. In the process of the wavy thermal conductive sheet 5 and the substrate 1 clamping the silicon carbide device 2, the S-shaped thermal conductive sheet 7 is compressed, providing a downward extrusion force for the L-shaped thermal conductive sheet 8, so that the L-shaped thermal conductive sheet 8 can evenly fit the silicon carbide device 2.

[0022] In addition to the above-mentioned embodiment, in this embodiment, a plurality of inverted conical holes 14 are provided on the lower surface of the L-shaped thermal conductive sheet 8, and the plurality of inverted conical holes 14 are evenly distributed in a matrix, and a single-component room temperature curing thermal conductive silicone is coated between the lower surface of the L-shaped thermal conductive sheet 8 and the upper surface of the silicon carbide device 2. Before assembly, it is necessary to coat the lower surface of the L-shaped thermal conductive sheet 8 with a single-component room temperature curing thermal conductive silicone. The length of the single-component room temperature curing thermal conductive silicone extending into the inverted conical hole 14 is less than the depth of the inverted conical hole 14, so the single-component room temperature curing thermal conductive silicone will not fill the inverted conical hole 14, and the air in the inverted conical hole 14 provides moisture for the curing of the single-component room temperature curing thermal conductive silicone to react chemically, thereby achieving condensation curing. After curing, the single-component room temperature curing thermal conductive silicone forms an inverted conical block in the inverted conical hole 14, and the inverted conical block and the lower surface of the L-shaped thermal conductive sheet 8 form a snap connection, so that the L-shaped thermal conductive sheet 8 can stably adsorb the silicon carbide device 2.

[0023] The thermally conductive spring structure of the present invention, which is composed of a thermally conductive plate 4, a wavy thermally conductive sheet 5, an I-type thermally conductive sheet 6, an S-type thermally conductive sheet 7 and an L-type thermally conductive sheet 8, can clamp the silicon carbide device 2 together with the substrate 1, and is connected to the ceramic package 3 through the thermally conductive spring to construct an efficient heat conduction and heat dissipation channel. In the process of the thermally conductive spring structure and the substrate 1 jointly clamping the silicon carbide device 2, first, the lower surface of the convex part of the wavy thermal conductive sheet 5 abuts against the upper surface of the silicon carbide device 2, and the friction force generated by the above abutment hinders the horizontal movement of the silicon carbide device 2 in the ceramic package 3. Then, the L-shaped thermal conductive sheet 8 coated with the single-component room temperature curing thermal conductive silicone on the lower surface will abut against the upper surface of the silicon carbide device 2 and compress the S-shaped thermal conductive sheet 7. The elastic force generated by the S-shaped thermal conductive sheet 7 will act on the L-shaped thermal conductive sheet 8. Finally, the single-component room temperature curing thermal conductive silicone is evenly spread between the lower surface of the L-shaped thermal conductive sheet 8 and the upper surface of the silicon carbide device 2, thereby improving the coating uniformity of the single-component room temperature curing thermal conductive silicone and facilitating heat dissipation.

[0024] In the above embodiment, the heat conducting plate 4 and the corrugated heat conducting sheet 5 are integrally formed in this embodiment, and the heat conducting plate 4 is an aluminum sheet or a copper sheet. The I-type heat conducting sheet 6, the S-type heat conducting sheet 7 and the L-type heat conducting sheet 8 are integrally formed, and the I-type heat conducting sheet 6 is a graphene film-coated aluminum sheet or a graphene film-coated copper sheet. The I-type heat conducting sheet 6, the S-type heat conducting sheet 7 and the L-type heat conducting sheet 8 have excellent elasticity and strength, and the addition of graphene can significantly reduce its thermal expansion coefficient and improve thermal conductivity.

[0025] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A SiC power device heat dissipation ceramic packaging structure, comprising a substrate (1) and a silicon carbide device (2), wherein a ceramic package (3) is fixedly provided on the upper surface of the substrate (1) and outside the silicon carbide device (2), characterized in that: The upper surface of the substrate (1) is in contact with the lower surface of the silicon carbide device (2); a plurality of heat conducting plates (4) are fixedly provided on the left and right inner walls of the ceramic package (3); the plurality of heat conducting plates (4) are arranged at equal intervals in the front-to-back direction; a wavy heat conducting sheet (5) is fixedly provided on the end surface of the heat conducting plate (4) away from the ceramic package (3); the lower surface of the convex portion of the wavy heat conducting sheet (5) is in contact with the upper surface of the silicon carbide device (2); and a plurality of I-type heat conducting sheets (6) are fixedly provided on the lower surface of the concave portion of the wavy heat conducting sheet (5) and are arranged in parallel at equal intervals on the left and right; an S-type heat conducting sheet (7) is fixedly provided at the bottom end of the I-type heat conducting sheet (6); and an L-type heat conducting sheet (8) is fixedly provided at the bottom end of the S-type heat conducting sheet (7) and located above the silicon carbide device (2).

2. A SiC power device heat dissipation ceramic packaging structure according to claim 1, characterized in that: An annular gap is provided between the outer wall of the silicon carbide device (2) and the inner wall of the ceramic package (3); a terminal (9) is fixedly provided on the upper surface of the silicon carbide device (2); the upper surface of the terminal (9) is fixedly passed through the upper surface of the ceramic package (3); and the two wavy heat conducting sheets (5) are located on the left and right sides of the terminal (9).

3. A SiC power device heat dissipation ceramic packaging structure according to claim 1, characterized in that: The left and right side walls of the ceramic package (3) are integrally formed with chamfered surfaces (10), the inner wall of the chamfered surface (10) is fixedly connected to the heat conducting plate (4), the outer wall of the chamfered surface (10) is fixedly provided with a heat sink (11), and the chamfered surface (10) is provided with a through hole (13) penetrating from top to bottom, and a heat conducting column (12) penetrating the through hole (13) is fixedly provided between the heat sink (11) and the heat conducting plate (4).

4. A SiC power device heat dissipation ceramic packaging structure according to claim 1, characterized in that: The lower surface of the L-shaped heat conductive sheet (8) is provided with a plurality of inverted conical holes (14), the plurality of inverted conical holes (14) being evenly distributed in a matrix pattern, a single-component room temperature curing thermal conductive silicone is coated between the lower surface of the L-shaped heat conductive sheet (8) and the upper surface of the silicon carbide device (2), the length of the single-component room temperature curing thermal conductive silicone extending into the inverted conical hole (14) being less than the depth of the inverted conical hole (14).

5. The SiC power device heat dissipation ceramic packaging structure according to claim 1, characterized in that: The heat conducting plate (4) and the wave-shaped heat conducting sheet (5) are integrally formed, and the I-shaped heat conducting sheet (6), the S-shaped heat conducting sheet (7) and the L-shaped heat conducting sheet (8) are integrally formed.

6. A SiC power device heat dissipation ceramic packaging structure according to claim 5, characterized in that: The heat conducting plate (4) is an aluminum sheet or a copper sheet, and the I-type heat conducting sheet (6) is a graphene film-coated aluminum sheet or a graphene film-coated copper sheet.

Images