Tanaka has developed an active brazing filler metal/copper composite material that can be used as next-generation heat sinks for power devices.
Tanaka Kikinzoku Kogyo K.K., which operates the Tanaka Precious Metals manufacturing business, has developed an active brazing filler metal/copper composite material that can be used as next-generation heat sinks for power devices.
A composite (cladding) of copper (Cu) material with active brazing filler metal (alloy of silver, copper, tin, and titanium, or AgCuSnTi) on one side, the new product can be joined directly to any material including ceramics—oxides, nitrides, and carbides—and carbon materials. It can also be tailored to customer needs, ranging from supply of prototypes using this product to brazing processes, testing, and evaluation.
With the new composite product, the thick Cu electrodes needed for high heat dissipation heat sinks can be formed directly on ceramics, which was difficult to do with existing etching processes. This makes possible even finer wiring pitch. And, since the material does not contain any solvents, there is no residue and bonding reliability is improved. Moreover, the brazing time can be greatly reduced, which leads to energy savings and reduced environmental impact.
The brazing filler thickness can be 10μm or less, which means that compared to earlier active brazing filler metal, silver bullion costs can be reduced by half or more and the brazing filler thermal resistance is halved. Because the Cu material is compounded, a pattern can be formed simply by setting the material, thereby reducing processing costs.
The new composite material can be used in a wide range of semiconductor applications, with expectations particularly high for deployment in the heat dissipation field.
In the power devices market, higher outputs and increased efficiency are demanded, and in conjunction with this, heat generation is rising. As a result, providing individual components with high heat dissipation, high heat resistance, and high bonding reliability and developing materials that are compatible with even further miniaturization are urgent priorities for the industry. This is especially the case in the market for eco-cars such as electric vehicles (EVs) and hybrid vehicles (HVs), the high-output laser diode market, and the market for next-generation heat sinks, demand for which in the PC, smartphone, and other markets is expected to grow.
To maintain high heat dissipation, high heat resistance, and high bonding reliability, it is first necessary to increase the thickness of the Cu plate. This product makes it possible to form electrodes on a thick Cu material and enhances bonding reliability without using etching, so it can be expected to contribute to higher heat dissipation.
Tanaka plans to begin full-scale sample shipments in 2021 and establish a mass production system in 2023.