WP-1 Wafer Bumping Printer

The WP-1 Wafer Bumping Printer is for precision stencil printing of solder paste on silicon wafers. The system is also designed for printing conductive epoxies and other materials on wafers. The WP-1 is capable of processing up to 60 wafers per hour.

The printer features look-up/look-down vision alignment system for alignment accuracies within ±5µ. To automatically load the wafers, the printer incorporates a robotic loader/unloader with dual cassettes and wafer aligner. After the wafer is loaded into the system by the robot and held in place with a vacuum, the stencil is registered to the wafer with fiducials. After printing, the wafer is removed from the printer by the robot and returned to the cassette.

Paste is dispensed automatically from cartridges with a choice of 300, 600, or 1200 g capacity. The system requires minimal operator intervention. Cleaning of the stencil is also automated using an independently programmable process for residual paste removal. Stencil cleaning modes are dry/wet and with/without vacuum. A captivated solvent bar optimizes solvent use.

The printer is capable of handling wafers up to 200mm in size. A kit is available for upgrading to 300mm wafers. The system accepts 20-in. x 20-in. and 29-in. x 29-in. tubular-framed stencils. Wafers are held in place with vacuum during fiducial find, align, print, and release stages. Insufficient vacuum will prevent printing or stencil release and sound an alarm.

Speedline Materials Deposition Systems, 16 Forge Park, Franklin, MA 02038-3137. Tel: 508-520-6999; Fax: 508-520-2288