A kind of directional heat conduction sheet and its preparation method, and semiconductor cooling device

Abstract

The invention belongs to the field of preparation technology of heat conduction sheets and semiconductor heat dissipation, and specifically discloses a preparation method of oriented heat conduction sheets. The method includes the following steps: S1. preparing a fluid composition for heat conduction sheets; S2. placing the fluid composition obtained in step S1 in In the orientation molding device, a high-speed shear force of circular motion is applied to the fluid composition layer by layer, so that the thermally conductive filler in the fluid composition is oriented along the shear direction to form an oriented thin layer composition, and the thin layers are combined The objects are collected in the mold layer by layer to form a continuous multi-layer collection, S3. the multi-layer collection is thermally cured to obtain an orientation composition block; S4. slice the orientation composition block along the direction perpendicular to the orientation , to get a directional heat conduction film. The aggregate prepared by the method of the invention has good orientation, few defects, and high efficiency, and the heat conduction sheet obtained through slicing treatment has high orientation, high thermal conductivity and uniformity, and at the same time, the heat conduction sheet can be well applied to semiconductor heat sinks middle.

Description

technical field [0001] The invention relates to the preparation technology of a heat conduction sheet and the field of semiconductor heat dissipation, in particular to a preparation method of an oriented heat conduction sheet and a semiconductor heat dissipation device. Background technique [0002] With the development of 5G technology, the power density of chips continues to increase, which puts forward higher requirements for the heat dissipation of chips. In heat dissipation components, thermally conductive silicone gaskets are usually used to reduce the interface thermal resistance between the chip and the heat sink and improve heat dissipation efficiency. [0003] At present, conventional thermally conductive silica gel gaskets are realized by filling isotropic spherical thermally conductive fillers (aluminum oxide, aluminum nitride, zinc oxide, etc.) in the silica gel matrix. Due to the low intrinsic thermal conductivity of spherical ceramic fillers, the gasket It is...

AI Technical Summary

Problems solved by technology

Baolima Technology Co., Ltd. published the patent CN100548099C, which uses a superconducting magnetic field and applies a certain frequency of vibration to make the carbon fiber with a high filling amount oriented along the direction of the magnetic field in the high-viscosity composition. Since the densities of the added alumina and carbon fiber fillers are respectively 3.8 times and 2 times the density of the silicone resin matrix, after the vibration is applied, it will cause the filler to settle, causing the overall composition to be uneven, and ultimately affect the uniformity of thermal conductivity

In addition, the high price and operating costs of superconducting magnets increase the cost

Dexerials Co., Ltd. announced CN107004651A, CN108463882A and CN109891577A. This method is to use the extrusion method to orient the carbon fiber along the extrusion method. We have found through our experiments that in order to prepare a high thermal conductivity sheet, when the mass ratio of the filled carbon fiber to the resin When it is greater than 1.3, the viscosity of the composition is large, the fluidity becomes poor, and it is difficult to extrude and process

In addition, when molding in a hollow mold, gaps are easily formed between adjacent extruded bodies due to poor fluidity, so the extrusion method is not suitable for the orientation of high-filling compositions

Published patent CN110734562A adopts annular groove to do circular motion, and the fiber in the composition in the groove is oriented along the direction of rotation, and there are following two disadvantages in this method: 1. the size of the obtained annular cured product is limited by the size of the annular groove, so , the width of the heat conduction sheet obtained by slicing the annular cured product along the radial direction is also limited by the width of the annular groove, and it is impossible to obtain a heat conduction sheet with a larger width; 2. When the width of the annular groove becomes larger, only the The composition on both sides of the tank wall is oriented, but the inside of the composition cannot receive the frictional force between the tank wall and the composition, which will cause insufficient orientation of the composition. This shortcoming is especially reflected in high-viscosity compositions, resulting in the inability to obtain High orientation, high thermal conductivity thermal conductive sheet

Images