Thermal conductive substrate and manufacturing method thereof

Abstract

The invention provides a thermal conductive substrate and a manufacturing method thereof. The thermal conductive substrate comprises a conductive metal layer, a high-electric and reliable thermal conductive polymer composite layer, a thermal conductive and low-temperature laminated polymer composite layer, and a thermal conductive metal base material layer, wherein the high-electric and reliable thermal conductive polymer composite layer is formed on one side face of the conductive metal layer by using a wet coating technique; the thickness of the high-electric and reliable thermal conductivepolymer composite layer is between 1 and 25 micrometers; the thermal impedance value of the high-electric and reliable thermal conductive polymer composite layer is less than 0.13 DEG C-in2 / W; the glass transition temperature of the high-electric and reliable thermal conductive polymer composite layer is more than 200 DEG C; the thermal conductive and low-temperature laminated polymer composite layer is formed on one side face of the high-electric and reliable thermal conductive polymer composite layer by using the wet coating technique; the thickness of the thermal conductive and low-temperature laminated polymer composite layer is between 0 and 65 micrometers; the thermal impedance value of the thermal conductive and low-temperature laminated polymer composite layer is less than 0.1 DEGC-in2 / W; and the thermal conductive metal base material layer is laminated on one side face of the thermal conductive and low-temperature laminated polymer composite layer. The thermal conductive substrate has the advantages of low thermal resistance, high electrical reliability and the like, and has high dimension stability in a warming environment.

Description

technical field [0001] The invention relates to a heat-conducting substrate, which is especially arranged between an electronic component and a heat dissipation module, and is used for conducting heat generated by the electronic component to the heat dissipation module. Background technique [0002] With the advancement of technology, electronic products are gradually developing towards high efficiency, and high-performance electronic components require relatively high power to drive, but with the increase in power, electronic components also generate considerable heat during operation, which accumulates in electronic components. The heat on the components will cause damage to the electronic components, resulting in a decrease in the life and reliability of the electronic components. The importance is also increasing, especially in the lighting industry, which is actively replacing incandescent light sources with LED light sources, which drives the increasing demand for LEDs...

AI Technical Summary

Problems solved by technology

[0004] In the first process, heat-conducting powder and thermoplastic organic resin are dispersed and mixed, and the mixed solution is respectively coated on the surface of the conductive metal layer (31) and the surface of the heat-conducting metal layer (33), and the two are baked and completely dried. , so that a thermoplastic heat-conducting composite film is formed on the surfaces of the two metal layers (31) (33) respectively, and then the two metal layers (31) (33) are bonded on the side where the thermoplastic heat-conducting composite film is formed, and passed through heat The pressing process melts the thermoplastic heat-conducting composite film and adheres the two metal layers (31) (33) to form a heat-conducting and insulating metal substrate for electronic components. The disadvantage of this process is that high-temperature pressing is required, and the pressing temperature Greater than 200°C, and it is easy to generate holes at the interface of each layer, thus resulting in an increase in thermal impedance;

[0005] In the second process, heat-conducting solid powder and liquid thermosetting organic resin are mixed to form a resin slurry (slurry), and the slurry is coated on the surface of the heat-conducting metal layer (33) to form a thin layer of heat-conducting composite resin slurry, and then The conductive metal layer (31) is covered on the thin layer of slurry, and the thin layer of thermally conductive composite resin slurry is thermally cured by heating and pressing to form a thermally conductive insulating layer. The disadvantage of this process is that the resin slurry has flow before thermal curing. In the process of heating and pressing, it is easy to have the problem of uncured slurry overflowing the board, and the glue slurry is prone to phase separation between the thermally conductive solid powder and the liquid thermosetting resin during the pressing process, resulting in thermal conductivity The solid powder is unevenly dispersed in the thermally conductive insulating layer, resulting in a decrease in the thermal conductivity and reliability of the insulating layer;

[0006] The third process is to uniformly knead inorganic heat-conducting powder, thermoplastics, and thermosetting epoxy resin at a temperature above the melting point of the resin to form a uniform rubber material. Oxygen curing agent and catalyst, and through plastic processing engineering (including extrusion molding (extrusion), calendering (calendering), injection molding (inection molding)) to make a thermally conductive and insulating composite film with a release material, the thermally conductive The polymer part of the insulating composite material film is an inter-penetrating network (IPN, inter-penetrating network), and the thermally conductive insulating composite film with the release profile removed is placed between the conductive metal layer (31) and the thermally conductive metal layer (33) , and then the insulating layer and the two metal layers (31) (33) are laminated to form the thermally conductive insulating metal substrate by a heating and pressing process. The disadvantage of this process is that the rubber material preparation process needs to be kneaded at high temperature, and thermoplastic It is a high-viscosity fluid during the high-temperature kneading process, and the inorganic heat-conducting powder is not easy to disperse evenly in it, and the heat-conducting and insulating composite film with an interactive penetration structure must be heated above the melting point of the thermoplastic when pressing, so it is easy to cause The surface of the metal layer (31) (33) cannot be evenly leveled, and gaps or holes are formed at the interface, which increases the thermal resistance value of the heat-conducting insulating metal substrate

[0007] The thermally conductive insulating metal substrates prepared by the above three processes are limited by the influence of electrical reliability, the thickness of the thermally conductive insulating layer must be greater than 75 microns (μm), and in order to reduce the thermal impedance of the thermally conductive insulating layer, The thermal conductivity of the thermally conductive insulating layer must be improved, so the volume percentage of the added thermally conductive powder must be greater than 50%, resulting in poor mechanical strength of the thermally conductive insulating composite material, which is easily perforated or cracked by external forces, making Decreased electrical reliability

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