Recetly a Japan factory has developed a copper powder that can be joined to electronic parts without heating at a high temperature. The heating temperature is about 200 ° C, which is 100 ° C lower than in the past. It does not melt other materials and can be directly used as a bonding material. It is expected to be used in power semiconductors for controlling power supplies instead of high-heat-resistant but expensive silver powder, and the price will be reduced to half.
Copper is oxidized as soon as it is too small, so a sintering temperature of about 300 ° C is required, but other electronic parts are also melted, so it has been difficult to apply it to bonding materials for electronic parts. The diameter of the copper powder developed this time is 30 nm. When processing, the plural particles will be combined to form a block with a total diameter of 100-200 nm. In the past, the diameter of the copper powder particles was 100 to 200 nm, and the smaller the particles, the lower the temperature required for sintering the metal powder.
In order to be used in the bonding materials of power semiconductors, the company has already launched samples to reach 1 billion yen in revenue within 5 years. Since the power semiconductor for controlling the power supply releases a high temperature of about 200 ° C, at this temperature, as long as copper can be used instead of expensive silver, the material cost is effectively reduced. The company also uses copper powder processed into a paste to study how it is used as a material for making circuits.