| Budget Amount *help |
¥11,300,000 (Direct Cost: ¥11,300,000)
Fiscal Year 2000: ¥2,800,000 (Direct Cost: ¥2,800,000)
Fiscal Year 1999: ¥8,500,000 (Direct Cost: ¥8,500,000)
|
|---|
| Research Abstract |
This project describes the development of the micro-ice jet machining (IJM) device for the via fabrication on the resin isolation film of semiconductors, which is capable of intermittent blasting of micro-ice. The IJM process is similar to an abrasive jet machining (AJM), and selectively removes softer materials than the micro ice of pure water. IJM uses fine ice powders, which are produced under the low temperature condition of -150 ℃ or below. First, the spray pattern from the nozzle and the injected velocity distribution were measured using PIV (Particle Image Velocimetry) system. The size of ice chamber for IJM device was designed on the basis of measured spray pattern and calculated value of critical freezing time of water drop. Then, we investigated the blasting characteristics and the possibility of the IJM process. As the ice jet stream from the nozzle is focused onto the workpiece, small holes or slots can be machined. The blasted micro-ice is melted and has no influence upon the environment of production processes. Al, Cu, Si and resin plates were blasted with ice jet stream. Al and Cu, which have similar hardness, were not machined. The surface roughness, however, increased and its center of blasted area rises due to the residual stress. Si (single crystal wafer), which is harder than micro-ice, was not machined and has no influence on the surface. Resin, which is softer than the micro-ice, was removed. Then, we made a resinoid isolation film on the silicon wafer and a metal mask was overlapped. Ice jet was blasted on the mask. Only the resin isolation film was removed, and the same pattern of the mask was transcribed onto the film. The selective removal process was demonstrated.
|
