JTEKT recently demonstrated a new double-disc horizontal grinder that simultaneously grinds both sides of silicon wafers to +/- 1 micron from as-sliced condition. The DXSG320 performance represents a massive improvement in accuracy and productivity over the single-spindle vertical grinders common in the chip industry today which grind to 3-4 microns, according to the company.
The new machine design is a first in the industry. A total of 300 machines are installed around the world. Previously, JTEKT offered a single-spindle wafer grinding machine.
A further advantage, the new DXSG320 grinder footprint is approximately 20% smaller than other machines while including fully automated work handling internal to the machine. Wafers are put into a fixture and loaded into a rack system to carry the wafers into the machine for sizing and finishing to customer specifications.
To assure correct stock removal and optimum quality, wafer thickness is measured before and after grinding. During grinding, discs float in the fixtures and spin during the grinding process, resulting in rapid, even material removal. Since there is no need to flip over the part during the grinding process, users will save considerable cycle time. According to a spokesman, the machine’s single-wafer grinding method makes for ease of automation and easy traceability.
“A key advantage this machine offers over the vertical spindle design is equal stock removal on both sides of the disc in one operation. This not only reduces the need for multiple machines to achieve desired production levels, users are also assured of consistently removing the same amount of stock on both sides, compared to vertical machines which only grind one side at a time.”
Key features of the grinder include a GW high-frequency spindle with air static pressure and a built-in motor to achieve high speed, high accuracy grinding. In-process, wheel positioning is automatic through high-accuracy air gauging. The use of pure water instead of coolant is environmentally friendly.
The machine is compatible with a variety of data collection systems through easy-to-use communication software.