Fujitsu Corporation

Kaoru Hashimoto

Kyoichiro Kawano

Tatsuo Chiyonobu

Kouji Watanabe

Nobuo Kamehara

Koichi Niwa

Koji Watanabe

Takeshi Okuyama

Osamu Taniguchi

Teru Nakanishi

Masato Wakamura

Isao Watanabe

Kazuaki Karasawa

Masayuki Ochiai

Kyohei Murakawa

Joe Yamaguchi

Tatuo Chiyonobu

Hitoshi Suzuki

Toshimi Kawahara

Mineharu Tsukada

Wataru Yamagishi

Motoyuki Nishizawa

Hiromitsu Yokoyama

Mayumi Osumi

Seiichi Yamada

Toshihiro Sakamura

The conductive material comprises a first metal material having a melting point of not more than 250&#xb0; C. and a second metal material having a melting point of not less than 500&#xb0; C., and is paste at a temperature not more than 250&#xb0; C. Whereby the conductive material can have much higher conductivity than the resin paste. The conductive material can be used in paste, whereby the conductive material can be buried in the via-hole in the same way as the resin paste.

Conductive material and method for filling via-hole

In a method of manufacturing piezoelectric ceramics by molding pre-fired or calcined powders of ingredients of a piezoelectric ceramic material and sintering the powder mold at a high pressure, the powder mold is pre-sintered at an atmospheric pressure before sintering at high pressure (HIP). Preferably, after the sintering HIP step, a thermal treatment is performed at a temperature of from 500 to 1000.degree. C. under an oxidizing atmosphere. For a Pb(Zn.sub.1/3 Nb.sub.2/3)O.sub.3 --PbTiO.sub.3 based piezoelectric ceramic, the composition is preferably set to (Pb.sub.1-x Ba.sub.x)[(Zn.sub.1/3 Nb.sub.2/3).sub.1-y Ti.sub.y ]O.sub.3, where 0.001&lt;x&lt;0.055 and 0.05&lt;y&lt;0.20.

Method of manufacturing piezoelectric materials

A bump forming step forms a predetermined number of bumps on at least a first one of two components. A height measuring step measures the heights of the predetermined number of bumps. A fixing step fixes the two components together by means of the bumps with the distance between the two components determined, using the result of the height measurement, so that all of the predetermined number of bumps should come in contact with the second one of the two components. An oxide-film removing step removes the oxide film formed on the predetermined number of bumps after the height measuring step and before the fixing step. The fixing step comprises a press fixing step for press fixing the two components at the above distance by means of a press fixing method, and a melting step for causing the bumps to melt in a predetermined atmosphere so that the bumps firmly join the two components together. The distance is established by at least one of the press fixing step and the melting step.

Process of fabricating semiconductor unit employing bumps to bond two

A first contact member comprises a liquid conductor which comes into contact with a second contact member so as to establish the electric connection between the two contact members. A container contains the first contact member therein. The second contact member is pin-shaped. The container is tube-shaped and has a containing portion, which is filled with the liquid conductor, and has an opening through which the second contact member is inserted. An area contraction portion for contracting the cross sectional area of the container is formed at a position between the containing portion and the opening. The container is installed in a through hole provided in a base member. The container includes a pipe member of an electric conductor which comes into direct contact with the liquid conductor and a plug member to be inserted into the hole, before the pipe member is inserted, for preventing the liquid conductor from escaping from the container. The container is formed of elastic material. The portion of the container near to the opening is split into segments and portions of the segments are positioned away from each other as the portions are near to the opening so that the outer diameter of the segments is larger than the inner diameter of the hole before the container is installed into the hole, the segments approaching each other as the container is being inserted into the hole against the elastic force of the segments.

Connector employing liquid conductor for electrical contact

An electrical connecting device including a first circuit board providing thereon with input/output terminals, each of the terminals having a tip surface coated with gallium and a second circuit board providing thereon with contact terminals, each of the terminals having a tip surface coated with indium or tin. A low-melting point alloy layer is formed by a mutual action between gallium and indium or tin, when the input/output terminals of the first circuit board are in contact with the respective terminals of the second circuit board and the terminals are electrically connected to each other. The second metal layer includes a plurality of wire-like metal supports extending substantially perpendicular to the surface of the terminal and a low-melting point metal retained by the wire-like metal supports.

Electrical connecting device and method for making same

Metal such as solder is immersed in a heating medium containing a rosin or derivative thereof and an organic solvent and heated to a temperature above the melting point of the metal, to remove the oxide film of the metal and make the metal spherical. If a hardened caster oil or high softening point rosin or derivative thereof is further added as a thickener to the heating medium, the size increase of the metal particle can be prevented. By heating at a temperature lower than the melting point of the metal, the oxide film can be removed without making the particles spherical. Using thus obtained solder particles, fluxless soldering can be done. Also, a fluxless soldering method is provided.

Methods for making metal particle spherical and removing oxide film

An electrical connecting device including a first circuit board providing thereon with input/output terminals, each of the terminals having a tip surface coated with gallium and a second circuit board providing thereon with contact terminals, each of the terminals having a tip surface coated with indium or tin. A low-melting point alloy layer is formed by a mutual action between gallium and indium or tin, when the input/output terminals of the first circuit board are in contact with the respective terminals of the second circuit board and electrically connected to each other. The second metal layer includes a plurality of wire-like metal supports extending substantially perpendicular to the surface of the terminal and a low-melting point metal retained by the wire-like metal supports.

An electrical connecting method connects a first contact of a first object to a second contact of a second object. The electrical connecting method includes the steps of coating a Ga system liquid metal on at least one of the first and second contacts, where the Ga system liquid metal includes a predetermined weight percent of Bi, and contacting the first contact to the second contact via the Ga system liquid metal. The predetermined weight percent of Bi is selected such that the liquid state of the Ga system liquid metal is maintained when the first and second contacts make contact via the Ga system liquid metal.

Electrical connecting method

A process of producing a multiple-layer glass-ceramic circuit board having a copper conductor, comprising the steps of: forming throughholes in a glass-ceramic green sheet at sites where via-contacts will be formed; filling the throughholes with a powder mixture of a copper powder blended with a ceramic powder, the copper powder and the ceramic powder having a powder particle size providing a packing density comparable with or greater than that of the glass-ceramic green sheet when filled in the throughholes; printing a conductor paste on the green sheet having the throughholes filled with the powder mixture, to form a circuit conductor pattern on the green sheet; laminating a plurality of the green sheets having the conductor pattern formed thereon, to form a laminate body; heating the laminate body to thereby remove a binder therefrom and preliminary-fire the laminate body; and firing the preliminary-fired body.

Process of producing multiple-layer glass-ceramic circuit board

A process for a flip chip connection of a semiconductor chip includes the steps of forming a plurality of stud bumps on the semiconductor chip, on which a plurality of solder bumps are formed, in the vicinity of the outer periphery thereof and on the outside of the solder bumps, providing a cut groove between a plurality of the solder bumps and the stud bumps, mating the solder bumps on the semiconductor chip and the corresponding solder bumps on the circuit board and heating for subsequent integration of the mating solder bumps, and breaking way the outer peripheral portion of the semiconductor chip along the cutting groove after a flip chip connection in order to remove the stud bumps.

Process for flip chip connecting a semiconductor chip

A ceramic substrate, suitable for use as a circuit substrate on which integrated circuit chips are bonded, which consists essentially of, based on the weight of the substrate, 0.5.about.5.0% by weight of MgO, and 95.0.about.99.5% by weight of the total of Al.sub.2 O.sub.3 and SiO.sub.2, the proportion of the Al.sub.2 O.sub.3 to the SiO.sub.2 being in the range from 50:50 to 80:20 by weight.

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Kawasaki, Japan

Kaoru Hashimoto