Double-sided heat dissipation airtight packaging structure

Abstract

The utility model provides a double-sided heat dissipation airtight packaging structure, which comprises a chip, a drain electrode, a gate electrode and a source electrode, the chip is fixed at the top in the conductive cover plate, the drain electrode is fixed at the edge of the bottom end of the ceramic frame, and the drain electrode and the gate electrode are fixed at the bottom end of the ceramic frame and are respectively connected with the gate connecting column and the source connecting column. The upper surface and the lower surface of the chip are in direct contact with materials with good electric conduction and heat conduction, and the electrodes on the two surfaces dissipate heat outwards, so that the heat dissipation efficiency of the chip is improved; all the electrodes are positioned at the bottom, so that the patch is convenient to use; the electrodes at the bottom are separated by ceramics, and the ceramic frame has higher reliability compared with a plastic frame; the longitudinal top of the upper cover is connected with the bottom electrode through soft solder, and the whole interior has good space sealing performance.

Description

Technical Field

[0001] The utility model relates to a double-sided heat dissipation airtight packaging structure and its manufacturing process. Background Art

[0002] With the continuous improvement of the performance of electronic devices, especially high-performance computing devices such as servers, personal computers, mobile phones, etc., the heat output of their internal components has also increased significantly. Effective heat dissipation technology is crucial for ensuring the stable operation of devices, extending the service life of devices, and improving the energy efficiency ratio. At present, there have been many achievements in the research of heat dissipation media for chip heat dissipation technology in the market. For example, immersion cooling is achieved by using insulating liquids, and heat pipes formed by using the principle of phase change cooling, etc. However, these methods are limited in their wide application due to their system complexity, cost, and maintenance difficulty. Most of the existing power devices are packaged in a plastic packaging method during packaging, but plastic packaging cannot be completely sealed and belongs to a semi-sealed packaging. In addition, the high temperature during the operation of the internal devices in the packaging may accelerate the aging of the plastic and affect the long-term reliability.

[0003] For example, a power module and an electronic device disclosed in the publication number CN115966530A accelerate the heat dissipation ability of the power chip by setting a heat dissipation bottom plate at the bottom of the chip; and the chip and the metal frame are welded by implanting solder balls, so that the connection between the metal brackets is stable and the heat dissipation effect is enhanced. However, the top of the chip does not directly contact the heat dissipation component, nor is there a heat dissipation component set, resulting in only dissipating heat through the bottom heat dissipation plate, and the heat dissipation efficiency is not very high. Summary of the Utility Model

[0004] To solve the above technical problems, the utility model provides a double-sided heat dissipation airtight packaging structure.

[0005] The utility model is achieved through the following technical solutions.

[0006] A double-sided heat dissipation airtight packaging structure provided by the utility model includes a chip, a drain electrode, a gate electrode, and a source electrode; the chip is fixed at the inner top of a conductive cover plate, the drain electrode is fixed at the bottom edge of a ceramic frame, the drain electrode and the gate electrode are fixed at the bottom of the ceramic frame and are respectively connected to a gate connection column and a source connection column, the gate connection column and the source connection column respectively extend out of the top of the ceramic frame and are connected to the chip through solder balls, the conductive cover plate is buckled on the ceramic frame, and the edge is fixedly connected to the drain electrode.

[0007] The solder balls are tin balls evenly distributed on the gate and source of the chip.

[0008] The source occupies most of the middle position of the chip, a square notch is provided at one corner of the source, and a gate that is not connected to the source is provided at the notch.

[0009] The shapes and sizes of the source electrode and the gate electrode are respectively the same as the cross-sections of the source connection post and the gate connection post.

[0010] The bottom parts of the drain electrode and the gate electrode are respectively provided with a drain contact boss and a gate connection boss, and the bottoms of the drain contact boss and the gate connection boss are on the same plane as the bottom of the source electrode.

[0011] The beneficial effects of the present utility model are as follows: By using the cover plate as the connecting piece of the drain electrode, both the upper and lower surfaces of the chip are directly in contact with materials with good electrical and thermal conductivity, and heat is dissipated outward from both surfaces of the electrode, accelerating the heat dissipation efficiency of the chip; all the electrodes are located at the bottom, which is convenient for patch use; the ceramic is used to separate the electrodes at the bottom, and the ceramic frame has higher reliability than the plastic frame; the longitudinal top of the upper cover is connected to the bottom electrode through soft solder, and the whole interior has good space sealing performance. Description of the Drawings

[0012] Figure 1 It is a cross-sectional structure diagram of the present utility model;

[0013] Figure 2 It is a schematic diagram of the electrode position distribution of the present utility model;

[0014] Figure 3 It is a schematic diagram of the process flow of the present utility model.

[0015] In the figure: 1 - conductive cover plate, 2 - low melting point solder, 3 - chip, 4 - solder ball, 5 - high melting point solder, 6 - drain electrode, 61 - drain contact boss, 7 - gate electrode, 71 - gate connection post, 72 - gate connection boss, 8 - source electrode, 81 - source connection post, 9 - ceramic frame. Detailed Embodiment

[0016] The technical solution of the present utility model will be further described below, but the scope of protection is not limited thereto.

[0017] A double-sided heat dissipation airtight packaging structure includes a chip 3, a drain electrode 6, a gate electrode 7, and a source electrode 8; the chip 3 is fixed to the inner top of the conductive cover plate 1, the drain electrode 6 is fixed to the bottom edge of the ceramic frame 9, the drain electrode 6 and the gate electrode 7 are fixed to the bottom of the ceramic frame 9 and are respectively connected to the gate connection post 71 and the source connection post 81, the gate connection post 71 and the source connection post 81 respectively extend out of the top of the ceramic frame 9 and are connected to the chip 3 through the solder ball 4, the conductive cover plate 1 is buckled on the ceramic frame 9, and the edge is fixedly connected to the drain electrode 6.

[0018] The solder ball 4 is a tin ball evenly distributed on the gate and source of the chip 3.

[0019] The source electrode occupies most of the middle part of the chip 3. A square notch is provided at one corner of the source electrode, and the gate electrode connected to the source electrode is arranged at the notch, making the area of the chip smaller.

[0020] The shapes and sizes of the source electrode and the gate electrode are respectively the same as the cross-sections of the source connection post 81 and the gate connection post 71.

[0021] At the bottoms of the drain electrode 6 and the gate electrode 7, a drain contact boss 61 and a gate connection boss 72 are respectively provided. The bottoms of the drain contact boss 61 and the gate connection boss 72 are on the same plane as the bottom of the source electrode 8. When the chip is welded on the circuit board, the drain contact boss 61 and the gate connection boss 72 provided at the bottoms of the drain electrode 6 and the gate electrode 7 make there be a gap between the chip and the circuit board, enabling the heat conducted by the electrodes to be dissipated through the gap.

[0022] The present invention adopts a structure of welding both sides of the chip. The chip is inverted, and the back is connected to the upper cover using silver sintering technology. While the upper cover conducts heat, it serves as the drain electrode. The entire upper cover is in the shape of an inverted bowl, introducing the drain to the bottom. The lower side of the chip is connected to the bottom electrode through ball mounting and FC flip-chip technology. In this way, both the upper and lower sides of the chip are directly connected to electrodes with good electrical and thermal conductivity, and then heat is dissipated outward through the two-sided electrodes. All the electrodes are located at the bottom, facilitating surface mounting. Ceramics are used to separate the electrodes at the bottom, and the ceramic frame has higher reliability compared to the plastic frame. The longitudinal top of the upper cover is connected to the bottom electrode through soft solder, and the entire internal space is sealed. Through the above-described structure, double-sided heat dissipation and hermetic ceramic package are achieved. Moreover, the package of the present invention is very compact, without wire connection, and the package size can be made only slightly larger than the chip size.

[0023] During the manufacturing process, Al2O3 or AlN material is used as the material of the ceramic frame.

[0024] The melting point of the low-melting solder 2 is lower than that of the solder ball 4, and the melting point of the high-melting solder 5 is equal to that of the solder ball 4. When the chip is fixed on the cover plate, the solder ball will not melt. When the cover plate is welded to the ceramic frame, the melting point of the solder ball is the same as that of the high-melting solder. Only one sintering is used to connect the chip to the electrode assembly, and at the same time, the cover plate is welded to the ceramic frame to complete the package.

[0025] The drain electrode 6, the gate electrode 7, and the source electrode 8 are all made of CPC material. The CPC material has good electrical and thermal conductivity, which can accelerate the heat dissipation of the chip.

Claims

1. A double-sided heat dissipation airtight packaging structure, comprising a chip (3), a drain electrode (6), a gate electrode (7), and a source electrode (8), characterized in that: The chip (3) is fixed at the inner top of the conductive cover plate (1). The drain electrode (6) is fixed at the bottom edge of the ceramic frame (9). The drain electrode (6) and the gate electrode (7) are fixed at the bottom of the ceramic frame (9) and are respectively connected to the gate connection post (71) and the source connection post (81). The gate connection post (71) and the source connection post (81) respectively protrude from the top of the ceramic frame (9) and are connected to the chip (3) through solder balls (4). The conductive cover plate (1) is buckled on the ceramic frame (9), and its edge is fixedly connected to the drain electrode (6).

2. The double-sided heat dissipation airtight packaging structure according to claim 1, wherein: The solder balls (4) are tin balls evenly distributed on the gate and source of the chip (3).

3. The double-sided heat dissipation airtight packaging structure according to claim 2, wherein: The source occupies most of the middle position of the chip (3). A square notch is provided at one corner of the source, and a gate that is not connected to the source is provided at the notch.

4. The double-sided heat dissipation airtight package structure according to claim 3, characterized in that: The shapes and sizes of the source and the gate are respectively the same as the cross-sections of the source connection post (81) and the gate connection post (71).

5. The double-sided heat dissipation airtight packaging structure according to claim 1, wherein: The bottom parts of the drain electrode (6) and the gate electrode (7) are respectively provided with a drain contact boss (61) and a gate connection boss (72). The bottoms of the drain contact boss (61) and the gate connection boss (72) are on the same plane as the bottom of the source electrode (8).

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