Tokyo Japan, May 24, 2012 - New Japan Radio Co., Ltd. (New JRC) has introduced to the market, the technology of the thick copper wire bonding to aluminum electrodes on chip. Due to the reliability problem in conventional methods, this technology has been difficult to use in mass production. New JRC is the first in the world*1 to provide the established mass production technology about the thick copper wire bonding.
We have been putting our energies into research and development focusing a high reliability and an environmental load reduction. They are suitable for various applications requiring high voltage and high current such as industry equipments, electric vehicles, hybrid cars and smart grid power transmission/distribution.
New JRC has been researching and developing the thick copper wire bonding technology to apply it to our semiconductor products. Generally, the direct bonding to aluminum electrodes on chip with the thick copper wire has been difficult to use in mass production. In combination with bonding machine and material manufacturers*2, we have achieved the thick copper wire (over 200μm wire diameter) bonding to aluminum electrodes on chip as the established mass production technology using wedge bonding technology*3.
Wire bonding by thick copper
In industrial and electric vehicle applications, a longer temperature cycle*4 life is required due to a higher temperature operation request than consumer products. Our test results have shown that the temperature cycle life in the copper wire bonding is over 5,000-cycle, and around 2,000-cycle in the aluminum wire bonding.
Compared with aluminum wire, the copper wire has a higher fusing current.
The copper wire of 200μm diameter has the same characteristics as the aluminum wire of around 300μm diameter, so that the copper wire bonding saves wire material and reduces an environmental load. Moreover the copper thermal conductivity of 397W/mK is higher than the aluminum thermal conductivity of 238W/mK, so that the copper wire bonding has a higher heat dissipation and provides a low loss.