Cantilever-type displacement sensor using diffused silicon strain gauges

Abstract

Two kinds of alloys have been developed as cantilever and solder materials which are suitable for semiconductors. The cantilever material is an ironnickelcobalt ternary alloy that has a high elasticity with a tensile strenght of 1GPa, and a low thermal expansion coefficient 50 × 10 −7/K. The material for the solder is goldcoppergermanium ternary eutectic alloy that has a tensile strength of 1.1 GPa. Two strain gauges were diffused in parallel on a silicon pellet, and the pellet was bonded by the alloy solder on each surface of the cantilever, taking into account linearity and temperature effect. It was confirmed that the linearity was less than ±0.1% and a zero-point shift was under ±0.1% after 10 7 repeated stresses. The temperature effect was less than ±05% over a range of 230 – 390K using a non-linear compensation.