- Jun 18, 2022
- 3 min read

Electrode forming technology of Power device product

Updated: Apr 20

Hello! I'm TZ of sales department.

The power semiconductor market is currently expanding amid the demand for energy conservation due to the tight global power demand and countermeasures against the global warming problem.

Especially in the automobile industry, the demand for power modules, mainly silicon IGBTs, is increasing with the spread of hybrid vehicles(HV) and electric vehicles(EV). In order to meet the growing demand for power semiconductors, mass production factories of overseas power semiconductor manufacturers are increasing their production capacity by increasing the wafer size to 12 inches.

In order to follow the movements of overseas manufacturers, domestic power semiconductor manufacturers have also announced large-scale capital investment plans, including 12 inches mass production line.

In this article, we would like to introduce what kind of activities are being carried out at Tosetz　in response to the electrode forming technology required for power devices as described above.

WBG (Wide Band Gap), the next-generation power semiconductor

WBGs (wide band gap) such as silicon carbide (SiC), gallium nitride (GaN), gallium oxide (Ga2O3) for the next-generation power semiconductors are expected for applications such as in-vehicle inverters and 5G communications which market are growing further in the future.

In the electrode formation of power semiconductors, UBM (Under Barrier Metal) with electroless NiAu(ENIG) and NiPdAu(ENEPIG) plating films formed on the aluminum pad and gold bump formed by electroplating are generally used.

However, we are now in an era where higher withstand voltage, lower loss, and higher temperature operation are required for power semiconductors. In the next chapter, we will talk about what kind of manufacturing process will be required in the future.

Increased adoption of Cu and Ag electrode formed by electroplating method

For power semiconductors that require high withstand voltage, low loss, and high temperature operation, there is currently a movement to adopt copper plating or silver plating, which has low electrical resistance and high thermal conductivity. In addition, SiC requires higher temperature operation than silicon, and bonding with paste made from copper or silver is being considered without using solder.

In addition, modules with improved heat dissipation characteristics have been commercialized by sandwiching chips with thicker copper ribbons and copper plates without using conventional wire bonds.

In the future, we expect a wide variety of packaging technologies, such as a board type with built-in components that embeds chips in a multilayer printed circuit board and connects via copper plating, and a fan-out wafer level / panel level package (FO-WLP, FO-PLP) type, to be applied to power device products.

Tosetz’ prototype / contract development / contract processing service

Tosetz supports a wide range of Cu, Au, Ni, magnetic film (Ni / Fe / Co) electroplating, electroless plating, etc. In addition, we can evaluate electroless plating of tungsten alloys with cobalt and nickel, which has a higher copper diffusion barrier effect than conventional electroless Ni plating.

We can collaborate with wafer processing manufacturers to evaluate the effect of dissolved oxygen in chemicals and pure water on the wafer rinsing process by applying our degassing system for the purpose of improving the quality of the entire wet process such as pre/post treatment of electroplating, photoresist removing and wet etching.

This blog post also contains details such as the analysis and measurement environment, so if you are interested, please see it!

Proposal of Tosetz’ prototype / mass production equipment

Tosetz design and manufacture manual, semi-automatic and automatic transfer type Cu / Ni / Au continuous laminated electroplating and electroless plating equipment that can achieve excellent film thickness uniformity suitable for customer requirements.

We support customized design of prototype and mass production equipment that meets your needs, from automatic transfer mechanisms that support thin and fragile wafers, small diameters to 12 inches, and large square substrates.