| 摘要 |
PURPOSE:To improve the production yield of a piezoelectric element by mounting and fixing the piezoelectric element on one main face of the stem through an adhesive where ferrite powder is mixed. CONSTITUTION:Many piezoelectric groups 341 are formed on the surface, which is polished into a mirror surface, of a wafer for piezoelectric element on a basis of orientation flat line by the PEP method. In element group 341, a pair of comb- shaped electrodes 35 and 36 at a prescribed interval are formed oppositely, and a surface wave is generated on the surface of element 341 and near it due to the voltage signal applied to input-side terminals 351 and 352, and this surface wave is converted to an electric signal again and is teken out from output terminals 361 and 362. Element 341 is mounted and fixed to stem 39, where system pins 38 corresponding to terminals 351, 352, 361, and 362 are planted, through adhesive 40 including ferrite powder, and pins 38 and terminals 35 and 36 are connected. Reverse face 322 of the piezoelectric element is processed into fine rough face 371 to be able to restrain warp of the wafer to a prescribed value or less, so that cracks of the wafer can be reduced to set the yield of the piezoelectric element to a fraction defective of 10% or less. |
