| 摘要 |
PROBLEM TO BE SOLVED: To reduce area and height dimensions by forming an input terminal of an IC chip on the opposite face from a circuit terminal and connecting a piezoelectric element to the input terminal on the opposite face. SOLUTION: A crystal oscillator is formed by hermetically enclosing a piece of quartz crystal 2 and an IC chip 3 in a package container 1. The chip 3 exposes circuit terminals 16 to one principal plane and a crystal terminal 14(ab) to the opposite. That is, an oxide film is formed on the principal plane, and respective elements are connected to each other with an alumina film to form the terminals 16 to be electrodes for fetching power source, output, grounding, etc. Then, the terminal 14 connected to a field effect transistor (FET element) as an amplifier for oscillation is formed on the other principal plane. Thus, the crystal 2 is connected to the terminal 14 on the opposite plane from the terminals 16 of the chip 3. Since the terminals 16 on the principal plane are exposed, without being covered with the crystal 2, the chip 3 does not always have to be equal to or larger than the plate face of the crystal 2. In such a case, the chip 3 is connected directly to the bottom of a container main body 5 by facedown bonding.
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