The benefits of the inorganic metals tungsten and copper are combined in the alloy known as tungsten-copper (W-Cu).Specifically, it not only has the characteristics of high melting point, high density and low expansion coefficient of metal tungsten, but also has good electrical and thermal conductivity of Copper is a common material for microelectronic packaging since it is a metal.
It should be noted that by altering the composition of tungsten copper to more closely match the thermal expansion coefficient of the chip, the thermal conductivity and thermal expansion coefficient of W-Cu alloy can both be modified. Additionally, the alloy's flatness and surface grit will have a significant impact on the chip's quality. Generally speaking, an alloy's benefits to enhancing chip performance increase with its visual quality.
Common production methods of tungsten copper alloy
(1) Powder metallurgy method: the technological process is powder making-ingredient mixing-compression molding-sintering infiltration-cold working. The characteristics are that the product uniformity is not good, there are many voids, the density is lower than 98%, the operation is cumbersome, the production efficiency is low, and it is difficult to mass produce.
(2) Injection molding method: it is to mix nickel powder, copper tungsten powder or iron powder with tungsten powder, then add organic binder for injection molding, after which the binder will be removed by steam cleaning, irradiation, and hydrogen sintering. High-density products can be obtained.
(3) Copper oxide powder method: Copper oxide powder is reduced to produce copper, and then the copper is formed into a continuous matrix in the sintered compact, and tungsten is used as a strengthening framework, and then the mixed powder is sintered in wet hydrogen at a lower temperature, that is product available.
(4) Tungsten skeleton infiltration method: first press the tungsten powder into shape, and sinter it into a tungsten skeleton with a certain porosity, and then infiltrate copper. This method is suitable for the preparation of tungsten-copper products with low copper content, and the products have the disadvantages of low density and insufficient electrical and thermal conductivity.