Piezoelectric vibrating reed, piezoelectric vibrator, method for manufacturing piezoelectric vibrating reed, and method for manufacturing piezoelectric vibrator

Abstract

A piezoelectric resonator plate includes at least a pair of excitation electrodes and at least a pair of extraction electrodes. The pair of extraction electrodes are respectively extracted from the pair of excitation electrodes to electrically and mechanically bond the pair of excitation electrodes to an external electrode. The pair of extraction electrodes each include a distal end portion. The distal end portion includes a connecting electrode extracted to a vicinity of one end portion on one principal surface of the piezoelectric resonator plate. The connecting electrodes each include a top surface where a first metal film to be bonded to the external electrode is formed. The first metal film includes a top surface with two or more protruding portions. The first metal film has a larger surface roughness and a smaller area compared with the respective connecting electrodes. The protruding portions are formed with cross-sections in curvature shapes.

Description

technical field [0001] The present invention relates to piezoelectric vibrating reeds used in electronic products and the like, piezoelectric vibrators using the piezoelectric vibrating reeds, and methods for manufacturing them. Background technique [0002] Piezoelectric vibration devices represented by piezoelectric vibrators are widely used in mobile communication devices such as mobile phones. As one of piezoelectric vibrating pieces used in piezoelectric vibrators, there is a crystal vibrating piece. Excitation electrodes, lead-out electrodes for extending these excitation electrodes to the ends of the crystal vibrating piece, and the like are formed on the front and back principal surfaces of the crystal vibrating piece. Such a crystal vibrating piece is bonded to a terminal electrode (connection electrode) formed on the end of the lead-out electrode of the crystal vibrating piece by using a conductive bonding material to connect the terminal electrodes formed inside ...

AI Technical Summary

Problems solved by technology

[0004] However, the structure in Patent Document 1 not only increases the number of manufacturing steps required for electrode formation, but also complicates the electrode structure.

Therefore, it becomes a structure that is expensive and unsuitable for miniaturized piezoelectric vibrators that require a simple structure.

In addition, in the case of using plated bumps as metal bumps, since the shape of the top surface is flat, if ultrasonic bonding is performed by the FCB method, only the peripheral part of the top surface of the plated bumps is deformed and bonded, and the plated bumps The middle area of ​​the top surface cannot be bonded, thus making the effective bonding area (efficiency) smaller

In order to avoid such a problem, the piezoelectric vibrating piece can be bonded to the inside of the package with a strong ultrasonic wave, but in this case, a strong external force is applied to the piezoelectric vibrating piece, which will increase the vibration The new problem of damage to the piezoelectric vibrating piece

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