Kyoritsu Electrical Instruments Works, Ltd.

Showa Denko K.k.

Kyoritsu Electrical Instrument Works, Ltd.

Takeo Kuramoto

Takashi Shoji

Satoshi Noda

Masataka Watabe

Takekazu Sakai

A method of forming a solder film on a metallic surface such as a pad of a metallic circuit of a printed circuit board and a lead frame of electronic parts, which is capable of forming a precise and fine pattern and which comprises selectively imparting tackiness to only a predetermined part of the metallic surface by means of a tacky layer-forming solution containing at least one compound selected from benzotriazole derivatives, naphthotriazole derivatives, imidazole derivatives, benzoimidazole derivatives, mercaptobenzothiazole derivatives, benzothiazole thiofatty acid derivatives, and triazine derivatives, adhering a powdered solder to the resulting tacky part, and then melting the solder by heating to thereby form a solder film.

Solder circuit

A method of forming a solder film on a metallic surface such as a pad of a metallic circuit of a printed circuit board and a lead frame of electronic parts, which is capable of forming a precise and fine pattern and which comprises selectively imparting tackiness to only a predetermined part of the metallic surface by means of a tacky layer-forming solution, adhering a powdered solder to the resulting tacky part, and then melting the solder by heating to thereby form a solder film.

Method of forming solder film

Solution for selectively imparting tackiness to a metallic surface

A method is available for forming a solder film on a metallic surface such as a pad of a metallic circuit of a printed circuit board and a lead frame of electronic parts which is capable of forming a precise and fine pattern. The method comprises selectively imparting tackiness to only a predetermined part of the metallic surface by use of a tacky layer-forming solution, adhering a powdered solder to the resulting tacky part, and then melting the solder by heating to thereby form a solder film.

Ampere-volt-wattmeter or the like

Portable volt-ohm-ammeter or the like

Volt-ohm-ammeter or the like

A center-opening clamp type ammeter provided with a pair of magnetic cores each having actuating means provided on the basal portion thereof and constructed so that the opening operation of one of the magnetic cores causes the other magnetic core to be opened and that when the opening operation is freed the magnetic cores are brought into a closed state.

Growing community of inventors

Tokyo, Japan

Takeo Kuramoto