Matsushita Electric Industrial Co., Ltd.

Tomohiko Niikawa

Kazuei Kenmochi

Kenroku Tani

Hideo Mifune

Kazuhiko Nasu

Atsushi Matsui

A method for manufacturing an electronic device having therein a lead frame and a vibration-generating element integrally provided on the lead frame. The lead frame and the element are first provided in a metallic mold assembly comprising an upper mold portion and a lower mold portion, the upper and lower mold portions respectively having recess portions so as to form a cavity when the upper and lower mold portions are assembled with each other. A first sealing material is injected into the cavity so that the element is covered by the injected first sealing material, the first sealing material having a shrinkage property and a low adhesion property. After solidification of the injected first sealing material, they are removed from the mold assembly and then immersed in a second sealing material at a vacuum state so that the second sealing material is impregnated between the first sealing material portion and the lead frame. The second sealing material impregnated therebetween is hardened so as to seal a gap formed therebetween.

Method for manufacturing electronic device including a vibration

A piezoelectric pressure sensor for detecting the amount of oil in an engine oil pan of an automobile, and liquid level or the amount of liquid such as water level in a water bath, makes use of the phenomenon that an impedance of an excited piezoelectric element varies between in a gas and in a liquid. The pressure sensor is insensitive to surrounding temperature, and has high response and is of simple construction.

Growing community of inventors

Osaka, Japan

Tomohiko Niikawa