Daiwa Fine Chemicals Co., Ltd.

Other

Ishihara Chemical Co., Ltd.

Harima Chemicals, Incorporated

Sumitomo Electric Industries, Limited

Hyogo Prefectural Government

Obata, Doni, Daiwa, Fine Chemicals Co., Ltd.

Ishibara Chemical Co., Ltd.

Obata, Dohi, Daiwa Fine Chemicals Co. Ltd.

Ishihaa Chemical Co., Ltd.

Keigo Obata

Takao Takeuchi

Yoshiaki Okuhama

Hidemi Nawafune

Masakazu Yoshimoto

Seiichiro Nakao

Nobuyasu Dohi

Seishi Masaki

Kiyotaka Tsuji

Tetsuji Nishikawa

Yukiyoshi Okada

Masatoshi Majima

Shinji Inazawa

Kazuki Ikeda

Ayao Kariya

Hidenori Tsuji

Shigeyoshi Nakayama

Shingo Kitamura

Dong-Hyun Kim

Yasuhito Kohashi

Naoya Inoue

Hiroshi Tanaka

Hisao Irie

Shunsuke Ishikawa

Takaaki Anada

Tadashi Yoshida

Osamu Masuyama

Emiko Tanaka

Shigeru Takatani

Masayuki Nishino

Yuji Kato

Tetsuya Kondo

Keiji Shiomi

Kyoko Kuba

Mitsuo Komatsu

Kim Dong Hyun

To develop stable, non-cyanide silver and silver alloy plating baths. The present invention is a silver and silver alloy plating bath, comprises: (A) a soluble salt, comprising a silver salt or a mixture of a silver salt and a salt of a metal selected from the group consisting of tin, bismuth, cobalt, antimony, iridium, indium, lead, copper, iron, zinc, nickel, palladium, platinum, and gold; and (B) at least one aliphatic sulfide compound comprising a functionality selected from the group consisting of an ether oxygen atom, a 3-hydroxypropyl group, and a hydroxypropylene group, with the proviso that the aliphatic sulfide compound does not comprise a basic nitrogen atom.

Silver and silver alloy plating bath

A flux contains resin having film forming ability, activator, solvent and at least one complex selected from silver complex and copper complex. The flux is used when soldering is performed onto a circuit having electroless nickel plating or further having gold plating on the electroless nickel plating. Allowing a barrier layer of silver or copper to deposit on the surfaces of lands suppresses the diffusion of nickel into the melted solder alloy during soldering, and also prevents phosphorous concentration. This improves the bonding strength of soldering and suppresses the reduction deposition of silver and/or copper to portions other than circuit patterns.

Flux for soldering and circuit board

A silver and silver alloy plating bath, includes (A) a soluble salt, having a silver salt or a mixture of a silver salt and a salt of a metal such as tin, bismuth, indium, lead, and the like; and (B) a particular aliphatic sulfide compound, such as thiobis(diethyleneglycol), dithiobis(triglycerol), 3,3'-thiodipropanol, thiodiglycerin, 3,6-dithiooctane-1,8-diol, and the like, which contain at least one or more of an ether oxygen atom, a 1-hydroxypropyl group, a hydroxypropylene group, or two or more of a sulfide bond in the molecule, and not containing a basic nitrogen atom. Compared to baths containing aliphatic monosulfide compounds, such as thiodiglycol or beta-thiodiglycol, which do not contain an ether oxygen atom, 1-hydroxypropyl group, a hydroxypropylene group, or two or more of a sulfide bond in the molecule, by having these particular compounds, the plating bath of the present invention has excellent stability over extended time, excellent co-deposition of silver and various metals, and excellent appearance of the electrodeposition coating.

A pretreatment solution for providing a catalyst for electroless plating and a pretreatment method using the solution are provided. The pretreatment solution comprises a silver colloidal solution containing, as essential components, at least the following components (I), (II) and (III): (I) silver colloidal particles, (II) one or more ions selected from an ion of a metal having an electric potential which can reduce a silver ion to metal silver in the solution and an ion oxidized at the time of reduction of the silver ion, and (III) one or more ions selected from a hydroxycarboxylate ion, a condensed phosphate ion and an amine carboxylate ion, the silver colloidal particles (I) being produced by the ion of the metal (II) having an electric potential which can reduce a silver ion to metal silver. When an object to be plated is pretreated by use of the pretreatment solution, provision of an effective catalyst for electroless plating is achieved.

Pretreatment solution for providing catalyst for electroless plating, pretreatment method using the solution, and electroless plated film and/or plated object produced by use of the method

A method for forming a circuit pattern includes at least a step (a) of subjecting a non-conductor to electroless copper plating to form a copper film and a step (b) of etching the copper film so as to form a circuit pattern. As a catalyst for the electroless copper plating, a silver colloidal solution is used containing as essential components at least the following: (I) silver colloidal particles; (II) one or more of ions of metal having an electric potential which can reduce silver ions to metal silver in the solution and/or ions which result from oxidation of the ion at the time of reduction of the silver ions; and (III) one or more of hydroxycarboxylate, condensed phosphate and/or amine carboxylate ions. The silver colloidal particles (I) are produced by the ion (II) of the metal having an electric potential which can reduce silver ions to metal silver. The circuit pattern may be formed on a printed wiring board.

Method for forming circuit pattern

According to present invention, there is provided a lead-free solder precipitating composition comprising a tin powder, and a complex of silver ions and/or copper ions and aryl phosphines, alkyl phosphine, phosphines or azoles. The solder precipitating composition can form proper lead-free solder on lands of a circuit board, without forming silver and/or copper film on the circuit board.

Solder precipitating composition

To provide a plating method, which enables wide industrial use of the redox system electroless plating method having excellent characteristics, and a plating bath precursor which is preferable for the plating method. The plating method comprises a process oxidizing first metal ions of a redox system of a plating bath from a lower oxidation state to a high oxidation state, and second metal ions of said redox system are reduced and deposited onto the surface of an object to be plated, wherein a process is provided in which by supplying the electrical current to the plating bath, the first metal ions are reduced from said lower oxidation state to thereby activate the plating bath. The plating bath precursor is formed stabilizing the plating bath so that reduction and deposition of the second metal ions substantially do not occur in order to improve its storing performance.

Plating method and plating bath precursor used therefor

The present invention provides a tin-copper alloy plating bath, tin-copper-bismuth alloy plating bath or tin-copper-silver alloy plating bath containing a soluble metal compound and a specific sulfur-containing compound. The plating bath of the present invention is an alloy plating bath containing tin and copper, the bath being capable of preventing deposition of copper on a tin anode by substitution, having low dependence of plated coating composition on current density, high bath stability and resistance to turbidness.

Plating bath and process for depositing alloy containing tin and copper

Redox system electroless plating method

An aqueous solution for obtaining a noble metal by chemical reduction containing at least one water-soluble compound or complex of a metal selected from the group consisting of gold, platinum, silver, and palladium as a source of the metal to be deposited, and at least one mercapto compound or sulfide compound or a salt thereof as a reducing agent. The reducing agent is typically mercaptoacetic acid, 2-mercaptopropionic acid, 2-aminoethanethiol, 2-mercaptoethanol, glucose cysteine, 1-thioglycerol, sodium mercaptopropanesulfonate, N-acetylmethionine, thiosalicylic acid, 2-thiazoline-2-thiol, 2,5-dimercapto-1,3,4-thiadiazole, 2-benzothiazolethiol, or 2-benzimidazolethiol. They may be used singly or in combination.

Aqueous solutions for obtaining noble metals by chemical reductive deposition

Aqueous solutions for obtaining metals by reductive deposition

A tin, lead, or tin-lead alloy plating bath comprising, as essential ingredients, an alkali metal salt, and a soluble divalent tin compound or/and a lead compound, all of an aliphatic or aromatic sulfocarboxylic acid of the general formula ##STR1## wherein R is a C.sub.1-4 hydrocarbon radical, M.sub.1 is a hydrogen atom or alkali metal atom, M.sub.2 is an alkali metal atom, and X.sub.1 and X.sub.2 are each a hydrogen atom, OH, COON, or SO.sub.3 N (where N represents a hydrogen atom or alkali metal atom).

Tin, lead, or tin-lead alloy plating bath

A tin-lead alloy plating bath based on a principal plating bath comprising an alkanesulfonic or alkanolsulfonic acid and both bivalent tin and lead salts thereof is characterized by the addition of a guanamine compound having the general formula ##STR1## wherein R.sub.1 and R.sub.2, which may be the same or different, represent each a hydrogen atom, C.sub.1-18 straight- or branched-chain alkyl radical, C.sub.1-18 straight- or branched-chain alkoxy-lower alkyl radical, or a C.sub.3-7 cycloalkyl radical, or R.sub.1 and R.sub.2 may combine to form a carbon cycle or hetero cycle, and A represents a lower alkylene radical.

Tin-lead alloy plating bath

A tin, lead or tin-lead alloy plating bath, which comprises

Tin, lead, and tin-lead alloy plating baths

A method of electroplating of tin-lead alloys, which comprises using a solution containing hydroxyalkyl sulfonic acid and its divalent tin salts and lead salts, said solution being mixed with reaction products of acetaldehyde with O-toluidine as additives for brightening.

Method of bright electroplating of tin-lead alloy

Growing community of inventors

Akashi, Japan

Keigo Obata