Abstract: A surface mounting base for an oscillator that is provided with: an insulation base comprising a casing wall having a through hole; a sealing glass that is filled into the through hole and forms a space part on one principal surface side of the insulation base; and a J lead terminal, which passes through the sealing glass and clamps an inner surface and an outer surface of the casing wall, and which has a holding part for a crystal element on a top surface of the sealing glass that is one principal surface side of the insulation base, and which has a tip end part bent in a concave shape projecting from a bottom surface of the sealing glass and extending from the inside of the casing wall towards the outside across a tip end surface, and in which the tip end part is soldered to the insulation base.

Abstract: A quartz crystal unit includes a casing body having a cavity defined therein and having an opening, a quartz crystal blank disposed in the cavity, and a metal cover closing the opening of the cavity and hermetically sealing the crystal blank in the cavity. The metal cover has a core made of Kovar, a barrier metal layer disposed on one principal surface of the core, and a brazing layer disposed on the barrier metal layer. The barrier metal layer is made of an alloy which is composed mainly of copper and which has a thermal expansion coefficient that is smaller than a thermal expansion coefficient of cupper. The metal cover is joined to a peripheral edge portion of the opening by the brazing layer. The barrier metal layer is preferably made of a copper-nickel alloy, and the brazing layer is preferably made of silver brazing material.

Abstract: A surface mounting base for an oscillator that is provided with: an insulation base comprising a casing wall having a through hole; a sealing glass that is filled into the through hole and forms a space part on one principal surface side of the insulation base; and a J lead terminal, which passes through the sealing glass and clamps an inner surface and an outer surface of the casing wall, and which has a holding part for a crystal element on a top surface of the sealing glass that is one principal surface side of the insulation base, and which has a tip end part bent in a concave shape projecting from a bottom surface of the sealing glass and extending from the inside of the casing wall towards the outside across a tip end surface, and in which the tip end part is soldered to the insulation base.

Abstract: A quartz crystal unit includes a casing body having a cavity defined therein and having an opening, a quartz crystal blank disposed in the cavity, and a metal cover closing the opening of the cavity and hermetically sealing the crystal blank in the cavity. The metal cover has a core made of Kovar, a barrier metal layer disposed on one principal surface of the core, and a brazing layer disposed on the barrier metal layer. The barrier metal layer is made of an alloy which is composed mainly of copper and which has a thermal expansion coefficient that is smaller than a thermal expansion coefficient of cupper. The metal cover is joined to a peripheral edge portion of the opening by the brazing layer. The barrier metal layer is preferably made of a copper-nickel alloy, and the brazing layer is preferably made of silver brazing material.