Ngk Spark Plug Company, Limited

Hideshi Matsubara

Kazuo Kimura

Motohiko Itai

Kozo Yamasaki

A printed circuit board includes a number of ball-shaped terminals provided on one main surface of the board. Each of the ball-shaped terminals includes a metallic ball brazed on a pad provided on the main surface of the board. A thin gold layer is deposited by plating on the surface of the metallic ball.

Printed circuit board

A method of making a laminate ceramic substrate with domed pads is provided. In the method, a ceramic green sheet is prepared which has a pair of first and second opposite main surfaces and a plurality of through holes extending between the first and second main surfaces. The ceramic green sheet is placed upon a flat elastic sheet in such a manner that the first main surface of the ceramic green sheet is in contact with the flat elastic sheet. Metallizing ink is filled into the through hole so that a portion of the ink protrudes beyond the first main surface to form domed protruded portions by elastic deformation of the elastic sheet. The green sheet (optionally placed upon at least one other green sheet in such a manner that the second main surface is in contact with the other green sheet) is then sintered, thereby forming the domed, protruded portions of the metallizing ink into domed pads.

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Nagoya, Japan

Hideshi Matsubara