| 摘要 |
<p>Apparatus for automatic lapping control, based on imbedding an electrode of special construction in a lapping plate of a lapping machine, including at least one piezoelectric wafer in the lapping load, sensing the resonance frequency of the piezoelectric wafers as they pass by the electrode, and automatically terminating the lapping when the resonance frequency equals or exceeds a target frequency; the special electrode construction comprising a facing of a dielectric material with a high dielectric constant and surrounded by an insulator having a low dielectric constant and an average wall thickness larger than its wall thickness at the surface of the lapping plate.</p> |
