Fujitsu Corporation

Hidefumi Ueda

Junichi Kasai

Masataka Mizukoshi

Yasuo Yamagishi

Nobuo Kamehara

Michio Sono

Masayuki Ochiai

Ichiro Yamaguchi

Koki Otake

Kazuhiko Mitobe

Yutaka Yamada

Koji Asano

Susumu Abe

Atsushi Shiraishi

A solder paste including a solder powder; and a flux including at least an activating agent, and acid anhydride obtained by a dehydration reaction of aliphatic carboxylic acid having up to seven carbon atoms. The solder paste provides excellent solderability, high corrosive resistance and a good shelf life, but not an offensive smell, during the soldering operation.

Solder paste and soldering method of the same

First and second ball forming plates are prepared. The cavities of the first plate and the cavities of the second plate are filled with solder paste, respectively. The first plate and the second plate are placed in a facing relationship to each other and heated to form metal balls each of which corresponds to the total metal components of the solder paste in one cavity of the first plate and one cavity in the second plate. The metal balls are formed in the cavities of the lower plate . The metal balls are transferred from the cavities of the first plate to a device on which bumps are to be formed.

Bump-forming method using two plates and electronic device

A method for fabricating solder bumps onto a semiconductor chip. A solder ball forming member having a flat surface and a plurality of cavities arranged on the flat surface in a predetermined pattern is prepared. The cavities are then filled with a solder paste, and the solder ball forming member is heated to a temperature higher than the melting point of the solder so that the molten solder powder in the solder paste form solder balls due to surface tension. The semiconductor chip is then moved toward the solder ball forming member to transfer the heated solder balls from the solder ball forming member to the semiconductor chip.

Method for fabricating solder bumps by forming solder balls with a

A method for fabricating a semiconductor device using a solder ball forming plate having cavities. The plate is made from a silicon plate having a flat surface in a &lt;110&gt; crystallographic plane, and an orientation flat in a &lt;1-11&gt; crystallographic plane. The cavities are formed on the flat surface of the plate by etching, using a mask having openings in the shape of rhombus arranged such that one side of the rhombus is generally parallel to the &lt;1-11&gt; crystallographic plane. As a result, the cavities having wedge-shaped bottom are formed. The cavities are then filled with a solder paste and are heated to form solder balls in the cavities while the plate in an inclined position. The solder balls are then transferred from the plate to a semiconductor chip.

Process for forming solder balls on a plate having apertures using

A manufacturing apparatus which thermal design is easy, and which is small in size and light in weight is provided which is operated by a person in a micro-gravity environment. The manufacturing apparatus has a manufacturing unit having an operation side on which an operation is performed directly by the hand of an operator who faces the front of the facility, and a housing section for supporting the manufacturing unit slidably along the operation side and in such a manner as to be pulled out from the front of the apparatus to the outside. The manufacturing unit is housed with the operation side being vertical, and slides substantially horizontally. Also, an observation facility is disposed between two manufacturing unit housed in a constant-temperature tank so that the two facing sides of the member are observed simultaneously.

Manufacturing apparatus for use in a micro-gravity environment

Growing community of inventors

Kawasaki, Japan

Hidefumi Ueda