Manufacturing method of metal-ceramic composite substrate and composite substrate manufactured through manufacturing method

Abstract

The invention discloses a manufacturing method of a metal-ceramic composite substrate and the composite substrate manufactured through the manufacturing method and belongs to the technical field of ceramic metallization. The manufacturing method comprises the following steps of forming a first brazing material layer on the surface of a ceramic substrate, wherein the first brazing material layer isa copper, silver and active metal brazing material layer; forming a second brazing material layer on the surface of the first brazing material layer, wherein the second brazing material layer is a copper and silver brazing material layer; forming a copper layer on the surface of the second brazing material layer; and sintering a metal-ceramic composite substrate precursor in vacuum. According tothe manufacturing method, an active metal in the first brazing material layer reacts with ceramic during vacuum sintering, so that the binding force is high and the thermal shock resistance is high. Copper and silver in the second brazing material layer are subjected to eutectic reaction with copper foil, so that the copper and the silver are tightly combined with the copper foil; and meanwhile, by adopting two brazing material layers, on one hand, the content of the silver is reduced and the cost is lower, and on the other hand, the content of the active metal is reduced, electrical impedanceis reduced and the metal-ceramic composite substrate is higher in high voltage resistance and high current resistance.

Description

technical field [0001] The invention relates to the technical field of ceramic metallization, in particular to a method for manufacturing a metal-ceramic composite substrate and the manufactured composite substrate. Background technique [0002] There are two general methods for manufacturing ceramic circuit boards of power modules or installing semiconductors on them. One is direct copper clad technology (DBC), which uses metal oxides as transition layers on ceramic substrates in an open or semi-open environment. Copper foil is directly covered on the top, so that the two are bonded to each other. The other is active metal brazing technology (AMB), which uses brazing materials containing active metals such as Ti, Zr or Hf to heat and weld the copper foil and the ceramic substrate together in a vacuum protection environment, so that the ceramic substrate and copper The foils are bonded to each other. Among them, the metal-ceramic composite substrate made by the AMB process...

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Problems solved by technology

[0003] However, at present, when the metal-ceramic composite substrate is formed by the AMB process, there is only one layer of brazing material. In order to ensure sufficient eutectic reaction with copper foil at the sintering temperature, this layer of brazing material can obtain a tightly bonded metal-ceramic composite lining. At the bottom, silver content ≥ 72wt% is required, too much silver content will increase the cost

On the other hand, this layer of brazing material needs to contain enough active metal components to react at the entire ceramic-brazing material interface, so the active metal content in the entire brazing material is too much, resulting in an increase in electrical impedance, making the metal-ceramic The flow capacity of the composite substrate is reduced

Such as patent literature [1] and patent literature [2], in order to obtain metal-ceramic composite substrates with non-contact parts, the silver content in the solder is required to be ≥ 90.0%, which greatly increases the manufacturing cost

[0004] Patent document [3] proposes a brazing material using a low content of silver (15% to 35%), but the electrical impedance increases due to the high content of active metal (4 to 8% Ti), and although the adhesion Increased strength, however, the metal plate is prone to cracking when bonded to the ceramic substrate

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