Dowa Mining Co., Ltd.

Dai-ichi Kogyo Seiyaku Co., Ltd.

Matsushita Electric Industrial Co., Ltd.

Masami Sakuraba

Masami Kimura

Junji Nakamura

Masaya Takahara

Masatoshi Suehiro

Masashi Echigo

Katsuaki Suganuma

Choju Nagata

Xiao-Shan Ning

Toshikazu Tanaka

Seiichi Nakatani

Tsutomu Nishimura

Takashi Ono

Nobutoshi Kawamura

Yutaka Mitsune

Shuji Saeki

Susumu Okada

A metal-ceramic composite substitute is produced by joining a metal plate to a ceramic substrate by using a brazing material in a paste form prepared by adding 10-14 parts by weight of a vehicle to 100 parts by weight of a powder of which the solid centent comprises 90.0&tilde;99.5% of an Ag powder, 0&tilde;9.5% of a Cu powder and 0.5&tilde;4.0% of an active metal powder, and 0.0&tilde;0.9% of a titanium oxide powder if necessary.

Brazing material for use in joining a metal plate to a ceramic substrate

Process for producing a metal-ceramic composite substrate

In the present invention, a metal-ceramic composite substitute is produced by joining a metal plate to a ceramic substrate by using a brazing material in a paste form prepared by adding 10-14 parts by weight of a vehicle to 100 parts by weight of a powder of which the solid centent comprises 90.0&tilde;99.5% of an Ag powder, 0&tilde;9.5% of a Cu powder and 0.5&tilde;4.0% of an active metal powder, and 0.0&tilde;0.9% of a titanium oxide powder if necessary.

Metal-ceramic composite substrates, producing methods thereof and brazing materials for use in such method

An electronic circuit substrate including an aluminum-ceramic composite material having an electronic circuit formed on aluminum or an aluminum alloy plate of the aluminum-ceramic composite material which is prepared directly solidifying molten aluminum or an aluminum alloy on at least a portion of a ceramic substrate.

Electronic circuit substrates fabricated from an aluminum ceramic composite material

A metal-ceramic composite circuit substrate having a ceramic substrate and a metal plate joined to at least one main surface of the ceramic substrate, the rate of voids formed on at least a joint surface at a semiconductor mounting portion of the metal plate per unit surface area being not more than 1.49%. The diameter of void formed on at least the joint surface at a semiconductor mounting portion of the metal plate is not larger than 0.7 mm. The surface undulation of the ceramic substrate is not more than 15 .mu.m/20 mm measured by a surface roughness tester in case that the ceramic substrate is joined directly to the metal plate. The metal plate is joined to the ceramic substrate through a brazing material containing at least one active metal selected from a group consisting of Ti, Zr, Hf and Nb. The ceramic substrate is at least one kind of ceramic substrate selected from a group consisting of Al.sub.2 O.sub.3, AlN, BeO, SiC, Si.sub.3 N.sub.4 and ZrO.sub.2.

Metal-ceramic composite substrate

A paste of active metallic brazing material is applied to the entire surface of each side of aluminum nitride or alumina ceramic substrate 1; circuit forming copper plate 3 having a thickness of 0.3 mm is placed in contact with one surface of the substrate and a heat dissipating copper plate 4 having a thickness of 0.25 mm placed in contact with the other surface; the individual members are compressed together and heated at 850.degree. C. in a vacuum furnace to form a joint; an etching resist is applied to the circuit forming copper plate and etching is performed with an iron chloride solution to form a circuit pattern and the unwanted brazing material is removed from the marginal portions; a second resist layer is applied and etched with an iron chloride solution to form a second marginal step; a third resist layer is similarly applied and etched to form a third marginal step; the completed circuit board having three marginal steps of which the lowest one is solely or partly made of the brazing material can withstand 1,500 heat cycles, which is the result that has ben unattainable by the prior art. Having such high heat cycle characteristics, the circuit board is suitable for use as semiconductor substrate in automobiles, electric trains and other applications that require high output power.

Semiconductor substrates of high reliability ceramic metal composites

A conductor pattern is formed on at least one surface of an AlN- or Si.sub.3 N.sub.4 -based ceramic substrate which is such that the ratio between the principal metal component binding with N to form the ceramic mass and the B in the BN remaining on the surface layer is no more than 50.times.10.sup.-6 as either B/Al or B/Si, wherein B/Al represents the ratio of I.sub.B to I.sub.Al where I.sub.B is the X-ray diffraction intensity of boron present on the surface layer and I.sub.Al is the X-ray diffraction intensity of aluminum, and B/Si represents the ratio of I.sub.B to I.sub.Si where I.sub.B is as defined above and I.sub.Si is the X-ray diffraction intensity of silicon. The thus produced circuit board has both a peel strength of at least 30 kg/mm.sup.2 and a capability of withstanding at least 30 heat cycles and, hence, satisfies the performance requirements of the recent models of power module ceramic circuit boards.

Power module circuit board and a process for the manufacture thereof

Molten aluminum and a ceramic substrate are held in direct contact with each other and thereafter cooled to have the aluminum joined directly to the ceramic substrate. This method is capable of consistent and easy production of aluminum-ceramics composite substrates having satisfactory joint strength, thermal conductivity and heat resistance characteristics. A ceramic member is fed successively into and through molten metal to directly bond the metal on the ceramic to produce a metal-bonded-ceramic (MBC) material at a low cost. An electronic circuit substrate made of an aluminum ceramic composite material wherein an electronic circuit is formed on an aluminum surface of the aluminum-ceramic composite material. The aluminum-ceramic composite material is made by directly solidifying molten aluminum or an aluminum alloy on at least a portion of a ceramic substrate.

Process for preparing a ceramic electronic circuit board and process for

A brazing material having 0.25-0.9 wt % of titanium oxide added to a basic formula consisting of 60-94.25 wt % Ag, 5-30 wt % Cu and 0.5-4.5 wt % of an active metal is processed to form a paste, which is applied to an AlN substrate and overlaid with a copper plate and heat treated to form a joint between the AlN substrate and the copper plate. A resist is applied to the copper plate to form a circuit pattern, which is etched to form a metallized circuit, thereby producing a metal-ceramics composite substrate capable of operation on high electrical power. The substrate is improved in various characteristics of a power module device over the composite substrates produced by using the conventional brazing materials.

Brazing materials for producing metal-ceramics composite substrates

A copper paste composition for low temperature firing on a ceramic substrate is comprised of inorganic components and organic vehicle components. The inorganic components mainly consist of cooper powder, cuprous oxide powder, cupric oxide powder and glass powder. The mixing ratio off the inorganic components of this composition is 100 parts by weight of copper powder, about 10 to 15 parts by weight of cuprous oxide powder, about 12 to 17 parts by weight of cupric oxide powder, and about 7 to 12 parts by weight of glass powder. The mixing ratio of the inorganic components with the organic vehicle components is about 95 to 70 parts by weight of the organic vehicle components. Also the the average particle size of the copper powder is in a range of about 0.5 to 3 .mu.m and the oxygen content of the copper powder is about 0.05 to 0.15 weight percent.

Copper paste composition

A copper conductor composition comprising a copper powder, an inorganic oxide powder, a glass powder and an organic vehicle, said copper powder having an average particle size of 0.5 to 3 .mu.m, a tap density of 3.0 to 5.0 g/cm.sup.3, and an oxygen content of 0.05 to 0.15% by weight. Zinc oxide powder and, optionally, nickel powder are used as the inorganic oxide powder. The composition which contains the copper powder having such an oxygen content as low as 0.05 to 0.15% by weight, can provide copper conductors having excellent conductor properties such as solderability, adhesive strength and matching property to resistances.

Copper conductor composition

A copper conductor composition having an improved solderability as well as a good adhesion, which comprises a copper powder, an inorganic binder and a boride or silicide of a metal such as W, Mo, Ti, Ta, Nb or Cr. The solderability is kept on a good level even if the composition is subjected to a firing operation repeatedly.

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Tokyo, Japan

Masami Sakuraba