| 摘要 |
PURPOSE:To prevent Q value lowering at a vacuum enclosure time by generating a soft material bank in the junction flat part of the outside circumference of a flat type case and forming junction materials in a part of the outside of the bank. CONSTITUTION:Bank 8 such as gold, silver and copper is provided along the outside circumference flat frame of case 1 which contacts with vacuum enclosure part 7, and junction materials 9 are provided outside this bank. The height of the bank is higher than that of junction materials, and a temperature where the bank generates adsorption gas much is selected higher than the melting point of junction materials. Gold chromium film 10 is evaporated to the enclosure junction face. A crystal vibrator piece is held between cases, and pressure is applied to crash the bank, and cases are heated and are enclosed. Since the surface of frame 2 of the vibrator piece is smooth, gas generated from junction materials 9 at a junction enclosure time is prevented from flowing into a package due to crashed bank 8, and air-tightness in- side and outside the package is sufficiently held and is kept in a high vacuum to prevent Q value from lowering at a vacuum enclosure time. Air-tight enclosure and vacuum enclosure are performed at the same time, so that a stable unit can be produced in a simple process. |
