Matsushita Electric Industrial Co., Ltd.

Fumio Hasuike

Masatoshi Kondo

Takashi Kanehisa

Katsuyoshi Takemura

Yoshifumi Okada

Kenji Nogawa

Satoshi Kaneda

Chuji Shibuya

A disclosed method of continuous making flexible printed circuits for use in radio set or the like appliances, includes punching holes in a continuous copper-film clad insulating substrate, forming photopolymer films on the faces of the copper films exposing the photopolymer film to photochemical light of a predetermined pattern, developing the exposed photopolymer film, etching the copper film utilizing remaining parts of the photopolymer film as etching masks, removing the remaining photopolymer films 40 and printing solder-resist films on selected parts. The improvement is to provide and retain selected oblong parts of said conductor metal film disposed on and parallel to longitudinal direction of the continuous substrate by, for example, covering these parts by etching-resist films. The retained oblong parts of the metal film serve to prevent shrinkage of the substrate during the conduct of further manufacturing steps thereby assuring registration of the patterns of the printed circuits and the printed solder-resist films.

Method of making flexible printed circuits

A method of manufacturing printed circuit sheets which is capable of efficiently manufacturing printed circuit sheets from a base sheet composed of a base material in a sheet form having applied at least on one surface an electrically conductive foil.

Method of manufacturing flexible printed circuit sheets

Growing community of inventors

Kadoma, Japan

Fumio Hasuike