The present invention is to provide a plating film which can improve soldering bond reliability of solder bond against the accumulation of thermal history.

The present invention is a multilayer plating film comprising an electroless nickel-germanium alloy plating film; an electroless palladium plating film; and an electroless gold plating film in this order.

The present invention concerns an electroless gold plating bath comprising a) gold ions; b) sulfite ions; c) iodide ions; d) at least one phosphonate compound according to formula (1) ##STR00001## wherein each X is independently an alkanediyl group; R.sup.1, R.sup.2, R.sup.3 and each R.sup.4 are independently alkanediyl groups; M is independently hydrogen, a metal atom or a cation forming radical; each n is a rational number and selected in accordance with the valency of the respective M; and b is an integer ranging from 1 to 10.
The invention further is directed to the use of the bath and a method for depositing a gold layer on a surface of a substrate. The bath is particularly suitable in the manufacture of printed circuit boards, IC substrates, semiconducting devices, interposers made of glass and the like.

The present invention concerns an electroless gold plating bath comprising a) gold ions; b) sulfite ions; c) iodide ions; d) at least one phosphonate compound according to formula (1) ##STR00001## wherein each X is independently an alkanediyl group; R.sup.1, R.sup.2, R.sup.3 and each R.sup.4 are independently alkanediyl groups; M is independently hydrogen, a metal atom or a cation forming radical; each n is a rational number and selected in accordance with the valency of the respective M; and b is an integer ranging from 1 to 10.
The invention further is directed to the use of the bath and a method for depositing a gold layer on a surface of a substrate. The bath is particularly suitable in the manufacture of printed circuit boards, IC substrates, semiconducting devices, interposers made of glass and the like.

The preparation and colloidal gold nanoparticles deposited using a wet-chemical, three-phase ligand-exchange procedure carried out at room temperature on anodic alumina oxide to enhance detection of materials using Surface-enhanced Raman Scattering (SERS) is disclosed.

An electroless palladium plating liquid containing at least hydrazine or a salt thereof as a reducing agent, which has excellent bath stability in the vicinity of acidity to neutrality range, long-term stability, and is capable of suppressing the Pd film deposition rate decrease caused by elution of etching resist. An electroless palladium plating solution of the invention includes a palladium compound, hydrazine or its salt, at least one selected from a group consisting of a compound represented by the following formula (1) or its salt and a compound represented by the following formula (2) or its salt; and a pH of 8 or less, NH.sub.2NHCOR.sub.1 (1), (NH.sub.2NHCO).sub.2(R.sub.2)n (2), wherein R.sub.1 represents H, NH.sub.2, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, NHNH.sub.2, or an aromatic group, wherein each of these groups may have a substituent; R.sub.2 represents (CH.sub.2) or an aromatic group, wherein each of these groups may have a substituent; and n represents an integer of 0 to 10.

An electroless palladium plating liquid containing at least hydrazine or a salt thereof as a reducing agent, which has excellent bath stability in the vicinity of acidity to neutrality range, long-term stability, and is capable of suppressing the Pd film deposition rate decrease caused by elution of etching resist. An electroless palladium plating solution of the invention includes a palladium compound, hydrazine or its salt, at least one selected from a group consisting of a compound represented by the following formula (1) or its salt and a compound represented by the following formula (2) or its salt; and a pH of 8 or less, NH.sub.2NHCOR.sub.1 (1), (NH.sub.2NHCO).sub.2(R.sub.2)n (2), wherein R.sub.1 represents H, NH.sub.2, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, NHNH.sub.2, or an aromatic group, wherein each of these groups may have a substituent; R.sub.2 represents (CH.sub.2) or an aromatic group, wherein each of these groups may have a substituent; and n represents an integer of 0 to 10.

Present invention is related to a metallic particle-deposition substrate having a metal substrate and multiple metallic particles attached thereon. The metallic particles are nano-particles with at least 90% of these nano-particles as single layer being evenly dispersed on the metal substrate. Each of the metallic particle is isolated without toughing or overlapping. The metal substrate has different material than the metallic particles in each preferred embodiment in the present invention. More preferably, at least 80% of the metallic particles have the distance between each metallic particle is at a range of 2-6 nm for better generation of hotspot effects. The present invention provides a fast production method for producing the substrate with heterogeneous interface. The metallic particles are evenly attached to the surface of the metal substrate to obtain better surface enhanced Raman effect as to apply for sensors in all kinds of field.

The present disclosure relates to a method for forming a glass structure having a metallized surface portion. The method may comprise forming a structure using a flowable first material, adapted to form a glass, which includes a metal component. The structure is then treated to remove substantially all solvents and organic components contained in the first flowable material. Finally, the structure is exposed to a bath of a metal salt during which nucleation occurs and a metallized surface coating is formed on at least a portion of an outer surface of the structure.

The present disclosure relates to a method for forming a glass structure having a metallized surface portion. The method may comprise forming a structure using a flowable first material, adapted to form a glass, which includes a metal component. The structure is then treated to remove substantially all solvents and organic components contained in the first flowable material. Finally, the structure is exposed to a bath of a metal salt during which nucleation occurs and a metallized surface coating is formed on at least a portion of an outer surface of the structure.

A method for manufacturing a wiring substrate includes forming a conductor layer including first and second pads, forming a resin insulating layer on the conductor layer, forming, in the insulating layer, a first opening exposing the first pad and a second opening exposing the second pad, forming a covering layer on the insulating layer such that the covering layer covers the first and second openings, forming a third opening in the covering layer such that the third opening communicates with the first opening and the first pad is exposed in the third opening, forming, on a surface of the first pad, a protective film formed of material different from material forming the conductor layer, removing the covering layer from the insulating layer, and forming a conductor post on the second pad such that the conductor post is formed of material that is same as the material forming the conductor layer.