News Article
Mitsubishi Electric advances SiC ingot processing
The firms new technology improves productivity of silicon carbide slice processing for semiconductor wafers
SiC is expected to be used increasingly in power semiconductors due to its superior energy-saving and CO2 emissions-reduction properties compared to silicon.
Until now, sliced wafers have been produced through multi-wire saw with diamond particles because SiC is the third hardest compound on earth.
But this method requires lengthy machining time and large kerf widths.
The new parallel multi-wire electrical discharge machining method utilises Mitsubishi Electric's proven electrical discharge technology for difficult-to-cut material, and employs a dedicated power supply specially developed for SiC.
The key technologies include
Simultaneous cutting of SiC ingots into 40 pieces
- Forty wire electrodes with a diameter of 0.1 mm aligned at 0.6mm intervals are rotated to cut 40 slices at once, improving productivity.
- The non-contact, thermal process-wire electrical discharge method slices faster and at closer intervals compared to contact cutting (220 microns or less cut at a speed of 80 microns per minute)
- More wafer slices extracted per SiC ingot for improved efficiency.
Power supply dedicated to SiC slice processing
- Simultaneous wire cuts with even energy enabled by 40 electrically independent power feed contacts to wire electrodes.
- Uninterrupted processing with even very thin (0.1mm) wire electrodes thanks to a newly developed high-frequency power supply tailored to the characteristics of SiC material.
Pending patents for the technology number 22 in Japan and 10 overseas.
Until now, sliced wafers have been produced through multi-wire saw with diamond particles because SiC is the third hardest compound on earth.
But this method requires lengthy machining time and large kerf widths.
The new parallel multi-wire electrical discharge machining method utilises Mitsubishi Electric's proven electrical discharge technology for difficult-to-cut material, and employs a dedicated power supply specially developed for SiC.
The key technologies include
Simultaneous cutting of SiC ingots into 40 pieces
- Forty wire electrodes with a diameter of 0.1 mm aligned at 0.6mm intervals are rotated to cut 40 slices at once, improving productivity.
- The non-contact, thermal process-wire electrical discharge method slices faster and at closer intervals compared to contact cutting (220 microns or less cut at a speed of 80 microns per minute)
- More wafer slices extracted per SiC ingot for improved efficiency.
Power supply dedicated to SiC slice processing
- Simultaneous wire cuts with even energy enabled by 40 electrically independent power feed contacts to wire electrodes.
- Uninterrupted processing with even very thin (0.1mm) wire electrodes thanks to a newly developed high-frequency power supply tailored to the characteristics of SiC material.
Pending patents for the technology number 22 in Japan and 10 overseas.
