Nippon Steel Corporation

Tosiharu Kikuchi

Tomohiro Uno

Yasuhide Ohno

Yasuhiro Suzuki

Tadakatsu Maruyama

Hiroaki Otsuka

Masashi Konda

Osamu Kitamura

Hisao Kuribayashi

A method of producing soft fine metal spheres for semiconductor packaging from a material selected from soft metals and soft alloys. A plurality of fine wires made of the material are arranged in parallel on a flat base plate. Each of the wires has a diameter of not more than 100 .mu.m. The fine wires are cut into wire chips having an equal mass relative to each other and a chip length/chip diameter ratio between 5 and 100 by utilizing a cutting jig having cutting edges which are arranged at a constant pitch. The resulting wire chips are arranged so that the chips are spaced apart a minimum distance sufficient to prevent the chips from merging when melted. The resulting spaced-apart wire chips are heated to a temperature up to but not exceeding 100.degree. C. above the melting point thereof, thereby forming the chips into molten spheres. The resulting molten spheres are cooled, thereby forming solid spheres having a diameter within about 5% of a desired diameter.

Method of producing fine metal spheres of uniform size

A method of bonding bumps to leads of a TAB tape comprises the steps of preparing a substrate which is provided with through-holes, each having a size which will not allow the bumps to pass therethrough, at positions corresponding to bonding positions of the leads of the TAB tape where the bumps are to be bonded; provisionally arranging the bumps at positions of the through-holes at one side of the substrate by reducing a pressure in another side of the substrate opposite to said one side thereof to such the bumps in said through-holes; disposing the substrate on which the bumps are provisionally arranged and said TAB tape in such a positional relationship that said bumps face to the bonding positions of the leads of said TAB tape; and bonding the provisionally arranged bumps to the leads at the bonding positions and an apparatus for arranging bumps in a positional relationship corresponding to bonding positions of leads of a TAB tape.

Method of bonding bumps to leads of tab tape and an apparatus for

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Kawasaki, Japan

Tosiharu Kikuchi