Method for adopting aluminum or aluminum alloy to directly braze aluminum nitride ceramics

Abstract

The invention provides a method for adopting aluminum or aluminum alloy to directly braze aluminum nitride ceramics. The method include the following steps that a pure Al or Al alloy coating serving as brazing filler metal is plated on the surfaces to be brazed of the AlN ceramics by adopting a physical vapor deposition coating method, then the two ceramics are arranged in the mode that the coated surfaces are oppositely attached, and after a pressing force is exerted, vacuum heating brazing is performed to obtain brazing connectors for using the Al or Al alloy to directly braze the AlN ceramics. According to the method, the Al or Al alloy is adopted to directly braze the AlN ceramics, the shortcoming that an existing brazing method needs to metallize the ceramics and accordingly transition layers are produced between a brazing seam and the ceramics is avoided, and the brazing connectors having high strength and high toughness are obtained. The method can perform brazing at lower vacuum degree, the very high brazing penetration rate of large-area planar brazing connectors is obtained, and the method can serve as a connecting technology to be used for machining and manufacturing of the AlN ceramics.

Description

technical field [0001] The invention relates to a brazing method for ceramic materials, in particular to a method for directly brazing AlN ceramics by using aluminum or aluminum alloy as brazing material, which is used in the field of ceramic processing. Background technique [0002] AlN and the most commonly used Al 2 o 3 They are all engineering ceramics with excellent performance. They not only have high strength and high temperature stability, but also have many excellent properties such as high insulation, dielectric properties, and corrosion resistance. They are widely used in modern industry and high-tech fields. Broad prospects for more applications. For example, in the electronics industry, since AlN has a higher 2 o 3 Nearly 10 times the thermal conductivity of metal Al and the thermal expansion coefficient matching with semiconductor materials such as Si, SiC, GaAs, etc., become a substitute for Al 2 o 3 An important substrate material for high-power integra...

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Problems solved by technology

However, since the wetting angle of aluminum melt to AlN can only be less than 90° above 850°C, the brazing temperature above 850°C will reduce the quality and performance of the joint due to severe overburning of the Al melt

[0004] A search of the prior art found that: Chinese patent [Method for connecting ceramics and metals, CN200910092748.8] discloses a method of coating a layer of micron-scale thick Al or Al alloy film on the surface of ceramics by hot-dip plating to realize ceramics Between ceramics and metal brazing connection method, the patent inventor in the paper "Aluminum and aluminum nitride ceramic bonding strength and mechanism research" [Wang Bo, Ning Xiaoshan, Li Sha. Aluminum and aluminum nitride ceramic bonding strength and mechanism Research, Journal of Inorganic Materials, 2011,26(3):249-253], reported the brazing results of AlN and Al at 670-820°C using this method, but this method is due to hot-dip coating of Al and Al The bonding strength between the alloy and AlN ceramics is not high, and the strength of the obtained brazed joint is still not ideal

[0005] There is still no report on direct brazing of AlN ceramics and obtaining high-strength joints using Al and Al alloys

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