Abstract: A microetching composition for copper or copper alloys comprising, (a) a cupric ion source, (b) an organic acid with an acid dissociation constant (pKa) of 5 or less, (c) a halide ion source, and (d) water. The composition can produce surfaces of copper or copper alloy exhibiting excellent adhesion to resins such as prepregs and resists and superior solderability. The composition can be very adaptable to the manufacture of printed wiring boards with highly integrated fine line patterns.

Abstract: A pause mechanism for a cassette tape recorder having a drive mechanism for accomplishing modes, such as a record mode, a playback mode, a fast forward mode and a fast rewind mode, and a switch for enabling or disabling the modes, comprises a lever for setting the switch on or off. The lever is designed to have a double-lever structure in such a manner that when a pause lever is operated in each of the modes, the switch can be set on or off without operating each mode lever.

Abstract: A process for electroplating a surface comprising copper and an insulating material, comprising: applying specific carbon particles or a palladium compound to this surface, microetching the copper to remove the specific carbon particles or the palladium compound, and providing electroplating. The process is characterized by using an aqueous solution comprising 5 to 60 wt % of sulfuric acid, 3 to 35 wt % of hydrogen peroxide, 0.01 to 10 wt % of a phosphonic group-containing amine or a salt thereof, and, optionally, 0.1 to 10 wt % of an amine other than the phosphonic group-containing amine, as a microetching agent. This process can ensure highly reliable electroplating to inner walls of printing wiring board through-holes.

Abstract: An etching solution for copper or copper alloys comprising, (a) sulfuric acid, (b) a persulfate, (c) at least one compound selected from imidazole, imidazole derivatives, pyridine derivatives, triazine, and triazine derivatives, and (d) water. The etching solution exhibits a high etching speed and does not oxidize the copper surfaces after etching.

Abstract: The invention relates to a process for directly electroplating a conductive metal to the inner walls of through-holes in printed-wiring boards. The process comprises steps of providing an aqueous dispersion containing graphite particles with an average particle diameter of 2 .mu.m or less or carbon black particles with an average particle diameter of 1 .mu.m or less; applying this aqueous dispersion to a surface of a nonconductive surface substrate; dipping the nonconductive surface in a strong acidic aqueous solution with pH 3 or lower to form a layer of said particles; and electroplating using the particle layer as a conductive layer.

Abstract: A method for roughening surfaces of copper or copper alloy to provide an excellent adhesion of a coated or laminated layer thereon, comprising treating said surfaces with an amount and for a time effective to roughen them with an aqueous solution comprising an azole compound, a copper compound dissolvable in the solution, an organic or inorganic acid and a halogen ion.

Abstract: A composition for treating surfaces of copper and copper alloys comprising a specific imidazole derivative and water, and an acid or a water-soluble solvent. The composition can produce a heat resistant organic film with superior solderability when applied to surfaces of copper or copper alloys. It is particularly useful as a rust preventing agent for printed-wiring boards.

Abstract: A novel benzimidazole derivative is disclosed. The benzimidazole derivative is represented by the following formula (I), ##STR1## wherein R.sup.1 is a hydrogen atom, a lower alkyl group, or a halogen atom; R.sup.2 is a hydrogen atom or a lower alkyl group; R.sup.3 is an alkylene group with 1 to 18 carbon atoms; and n and m are integers from 0 to 3. The compound has an excellent rust preventing effect and can be used as a component of a composition for the treatment of surfaces of copper and copper alloys comprising the benzimidazole derivative which is particularly useful in preventing rust in printed-wiring boards.

Abstract: A composition suitable for the treatment of surfaces of copper and copper alloys is disclosed. It comprises, (a) a cupric complex of an azole compound, (b) an organic acid having a boiling point or a decomposition point of 230.degree. C or lower, (c) a difficultly volatile complexing agent, (d) a complexing agent having a complexing power which is weaker than that of the azole compound, and (e) water. The treatment of copper or copper alloys with the composition produces abraded surface with moderate irregularities, thereby ensuring better adhesion of various resists thereto and increased solderability. The composition is particularly useful for the manufacture of printed-wiring boards.

Abstract: A novel benzimidazole derivative is disclosed. The benzimidazole derivative is represented by the following formula (I), ##STR1## wherein R.sup.1 is a hydrogen atom, a lower alkyl group, or a halogen atom; R.sup.2 is a hydrogen atom or a lower alkyl group; R.sup.3 is an alkylene group with 1 to 18 carbon atoms; and n and m are integers from 0 to 3. The compound has an excellent rust preventing effect and can be used as a component of a composition for the treatment of surfaces of copper and copper alloys comprising the benzimidazole derivative which is particularly useful in preventing rust in printed-wiring boards.

Abstract: Soldering flux and solder paste compositions which are non-acidic, low-residue, and non-corrosive, leaving no substantial residue after soldering without a subsequent cleaning process and yet exhibiting excellent solderability are disclosed. The compositions comprise (A) at least one compound which generates a peroxide by decomposition or oxidation when subjected to heating, and (B) at least one ester from an inorganic or organic acid which generates an acid by decomposition in the presence of compound (A). They are particularly advantageous for eliminating the cleaning process with a solvent such as Flon to solve the ozone layer destruction problem and for improving the performance of the in-circuit test for printed-circuit boards after soldering.

Abstract: A soldering flux includes at least one acid component and at least one ester component. The acid component is selected from among dibasic carboxylic acid, hydroxycarboxylic acid and keto carboxylic acid. The ester component is selected from among phosphoric ester, phosphorous ester and hypophosphite ester.

Abstract: Disclosed is a method for removing a layer of tin or tin-lead alloy from a copper substrate of a printed circuit board employing the two different reagents in a two-step procedure without damaging the substrate, and at the same time, preventing formation of whitish precipitates in the treating solution.In the first step, the layer of tin or tin-lead alloy is selectively removed with the first reagent having a comparatively mild oxidation capability, then in the second step the intermetallic layer consisting of tin and copper is removed with the second reagent having a comparatively strong oxidation capability.This process ensures a smooth and effective operation in the production of high quality printed circuit boards.

Abstract: A stripping solution for tin or tin alloys which comprises an inorganic and/or organic acid, an oxidizing agent and a heterocyclic compound free of a sulfur atom but containing a nitrogen atom in the form of .dbd.NH or .tbd.N as a ring-forming member.