| 摘要 |
PURPOSE:To permit to work the diaphragm with high efficiency and high accuracy in conformity with a requested size by a method wherein the working of a round hole for a silicon wafer for forming the diaphragm is effected by supersonic process in the diaphragm for a semiconductor pressure sensor. CONSTITUTION:The disk-like silicon wafer 7 is fixed by a vacuum chuck 12 and is located immediately below a tool 23 by driving a X-Y table 13 with the control signal of an operation control unit. Next, the slurry of loose abrasive grains, such as the same of Al2O3 or the like, and working liquid is supplied from a nozzle to a working position, further, supersonic oscillation is generated in an oscillating piece 20 by a supersonic oscillator 19 and is enlarged by a cone 21 and a horn 22 to deliver it to the tool 23. Subsequently, when the silicon wafer 7 is elevated by a pushing mechanism 9 to abut it against the tool 23, the round hole with bottom is formed and, further, a plurality of round holes 28 with bottoms are formed at predetermined positions with high efficiency and accuracy by moving the X-Y table 13. On the other hand, the height of the side wall of the diaphragm may be increased to reduce the effect of thermal strain upon bonding the diaphragm onto the seat table thereof, therefore, the reliability of measuring accuracy may be increased. |
