Abstract: A scrubber device is provided. The scrubber device may etch a backside of a wafer and may clean a frontside of the wafer simultaneously. The scrubber device may comprise a programmed controller adapted to supply a non-etching fluid to a frontside of the wafer whenever an etching fluid is supplied to the backside of the wafer.

Abstract: A resistive etching solution containing thiourea, which is particularly suitable for etching an electrically resistive material comprised of a nickel-chromium alloy. The resistive etching solution allows for fast and effective etching of a nickel-chromium alloy in cases where the ratio of (a) copper surface area to (b) nickel/chromium surface area, is relatively large, and where fine feature etching is desired.

Abstract: A processing solution preparation and supply apparatus includes a dissolving preparation bath to which a material powder and ultrapure water are supplied. This dissolving preparation bath is connected to a substrate processing apparatus via a pipe, and a processing solution prepared from the material powder on-site is supplied to the processing apparatus. To reduce an increase in the microorganism concentration in the ultrapure water, this ultrapure water is circulated substantially constantly. This suppresses deterioration and concentration fluctuations of a processing solution for use in processing of a semiconductor substrate, when this processing solution is supplied to the use side. This also reduces particles and improves the economical efficiency.

Abstract: A lead-containing copper-based alloy is immersed into a weak acidic or neutral etching solution having a buffer effect which is formed by adding an organic acid into a complexing agent having a high ability to form a complexing ion with lead, and lead particles present on the surface of the lead-containing copper-based alloy are then removed. The complexing agent is one of an organic ammonium salt such as ammonium acetate, or ammonium citrate, or may be an organic sodium salt such as sodium acetate, sodium tartrate, and sodium citrate. Preferably, an immersion temperature of the alloy to the etching solution falls within a range of from 10 to 50° C. The etching solution is agitated with oxygen or a gas containing oxygen blown thereinto during the immersion of the alloy into the etching solution. An extremely low voltage of −0.3 to +0.2 V vs. NHE is applied from outside to the lead-containing copper-based alloy as an anode.

Abstract: The invention includes a method of cleaning a surface of a copper-containing material by exposing the surface to an acidic mixture comprising NO3−, F− and one or more organic acid anions having carboxylate groups. The invention also includes a semiconductor processing method of forming an opening to a copper-containing material. A mass is formed over a copper-containing material within an opening in a substrate. The mass contains at least one of an oxide barrier material and a dielectric material. A second opening is etched through the mass into the copper-containing material to form a base surface of the copper-containing material that is at least partially covered by particles comprising at least one of a copper oxide, a silicon oxide or a copper fluoride. The base surface is cleaned with a solution comprising nitric acid, hydrofluoric acid and one or more organic acids to remove at least some of the particles.

Abstract: A method for treatment of the surface of a CdZnTe (CZT) crystal that provides a native dielectric coating to reduce surface leakage currents and thereby, improve the resolution of instruments incorporating detectors using CZT crystals. A two step process is disclosed, etching the surface of a CZT crystal with a solution of the conventional bromine/methanol etch treatment, and after attachment of electrical contacts, passivating the CZT crystal surface with a solution of 10 w/0 NH4F and 10 w/o H2O2 in water.

Abstract: A polishing composition comprising: (a) colloidal silica having a positively charged surface, (b) colloidal silica having a negatively charged surface, (c) at least one acid selected from the group consisting of nitric acid, hydrochloric acid, sulfuric acid, lactic acid, acetic acid, oxalic acid, citric acid, malic acid, succinic acid, butyric acid and malonic acid, (d) at least one anticorrosive selected from the group consisting of benzotriazole, benzimidazole, triazole, imidazole, tolyltriazole and their derivatives, and (e) water.

Abstract: An implantable prosthesis, for example a stent, is provided having one or more micropatterned microdepots formed in the stent. Depots are formed in the prosthesis via chemical etching and laser fabrication methods, including combinations thereof. They are formed at preselected locations on the body of the prosthesis and have a preselected depth, size, and shape. The depots can have various shapes including a cylindrical, a conical or an inverted-conical shape. Substances such as therapeutic substances, polymeric materials, polymeric materials containing therapeutic substances, radioactive isotopes, and radiopaque materials can be deposited into the depots.

Abstract: An etchant and a method for roughening a copper surface each capable of permitting copper with roughened surface which exhibits acid resistance and permits a copper conductive pattern and an outer layer material to be firmly bonded to each other therethrough in manufacturing of a printed wiring board to simplify the manufacturing. The etchant may contain an oxo acid such as sulfuric acid, peroxide such as hydrogen peroxide and an auxiliary component such as an azole and chlorine. The azole may comprise benzotriazole (BTA). The chlorine may be in the form of sodium chloride (NaCl). The etchant permits a copper surface to be roughened in an acicular manner.

Abstract: When iron group, especially high nickel, metal alloys that contain substantial amounts of copper are pickled, a displacement coating of copper that is called a “copper kiss” often forms on the pickled surface from the dissolved copper ions in the pickling solution before the pickling solution can be rinsed away. Traditionally this has been removed by treatment with aqueous ammonia, an annoying and potentially hazardous reagent that in many instances requires expensive pollution abatement devices. In this invention, copper kiss is equally effectively removed by treatment with a mixture of sulfuric acid and hydrogen peroxide, optionally also containing hydrofluoric acid.

Abstract: A chemical mechanical polishing slurry and method for using the slurry for polishing copper, barrier material and dielectric material that comprises a first and second slurry. The first slurry has a high removal rate on copper and a low removal rate on barrier material. The second slurry has a high removal rate on barrier material and a low removal rate on copper and dielectric material. The first and second slurries at least comprise silica particles, an oxidizing agent, a corrosion inhibitor, and a cleaning agent.

Abstract: There is provided an aqueous dispersion for CMP with an excellent balance between chemical etching and mechanical polishing performance. The aqueous dispersion for CMP of the invention is characterized by comprising an abrasive, water and a heteropolyacid. Another aqueous dispersion for CMP according to the invention is characterized by comprising an abrasive, water, a heteropolyacid and an organic acid. Yet another aqueous dispersion for CMP according to the invention is characterized by comprising colloidal silica with a primary particle size of 5-100 nm, water and a heteropolyacid. Preferred for the heteropolyacid is at least one type selected from among silicomolybdic acid, phosphorotungstic acid, silicotungstic acid, phosphoromolybdic acid and silicotungstomolybdic acid. Preferred for the organic acid is at least one selected from among oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, maleic acid, fumaric acid, phthalic acid, malic acid, tartaric acid and citric acid.

Abstract: A simple surface treatment process is provided which offers a high performance surface for a variety of applications at low cost. This novel surface treatment, which is particularly useful for Ti-6Al-4V alloys, is achieved by forming oxides on the surface with a two-step chemical process and without mechanical abrasion. First, after solvent degreasing, sulfuric acid is used to generate a fresh titanium surface. Next, an alkaline perborate solution is used to form an oxide on the surface. This acid-followed-by-base treatment is cost effective and relatively safe to use in commercial applications. In addition, it is chromium-free, and has been successfully used with a sol-gel coating to afford a strong adhesive bond that exhibits excellent durability after the bonded specimens have been subjected to a harsh 72 hour water boil immersion. Phenylethynyl containing adhesives were used to evaluate this surface treatment with a novel coupling agent containing both trialkoxysilane and phenylethynyl groups.

Abstract: Lead brass components for potable water distribution circuits (e.g., plumbing components made of CuZn39Pb3, containing 3% Pb), also chronium plated ones, are subjected to a lead-selective surface etching to reduce, in operation, the release of Pb caused by Pb surface “smearing”, resulting either from machining or molding; said elements are firstly contacted by an aqueous solution of an acid capable of forming soluble Pb salts, preferably a non-oxidizing solution, by simply dipping the components in the solution, e.g., a solution of 0.1 M sulfamic acid, at 20°-50° C. for 10 to 50 minutes, and, subsequently, the elements are passivated by immersion into a strong base aqueous solution, e.g., a solution of 0.1 M NaOH at 20°-25° C., for approximately 10 minutes; in this manner, plumbing components made of a copper based alloy containing Pb are obtained, which components, after 15 days of test according to US NSF STD61 procedure, release Pb in an amount less than 0.

Abstract: Controlled chemical etching of rotating metal substrates has been shown to be a feasible and economic method for the reproducible production of thin, reactive metallic foils such as copper foils. Foils thus prepared react readily with chemical substances, apparently by chemisorption. The organic-metal assemblies exhibit the same corrosion and wetting behavior as those prepared by other processes, and they readily undergo additional functional group transformations.

Abstract: Metal surfaces, particularly copper surfaces, which are oxidatively micro-etched to increase surface area through the use of molybdenum. The micro-etch solutions contain a proton source, e.g., a mineral acid, an oxidizer agent, e.g., hydrogen peroxide, an azole compound, and a molybdenum source. These micro-etched surfaces can further be rendered acid-resistant by exposure to a thiazole compound and/or a thiocarbamide compound. The thiazole compound and/or thiocarbamide compound may be provided either in the oxidative micro-etching solution or provided in a post-micro-etching solution.

Abstract: A method of manufacturing electronic components includes disposing a top metal layer (502) comprised of solder over a bottom metal layer (201, 202) comprised of titanium or tungsten, and selectively etching the bottom metal layer (201, 202) over the top metal layer (502) with an etchant mixture (601) comprised of an etchant, an additive to control the temperature of the etchant mixture (601), and another additive to reduce the redeposition of the top layer (502).

Abstract: A composition and process are described which are useful in treating metal surfaces, which composition comprises an oxidizer, an acid, a corrosion inhibitor, an organic nitro compound and, optionally, a benzotriazole with an electron withdrawing group in the 1-position which electron withdrawing group is a stronger electron withdrawer than a hydrogen group, optionally, a source of adhesion enhancing species selected from the group consisting of molybdates, tungstates, tantalates, niobates, vanadates, isopoly or heteropoly acids of molybdenum, tungsten, tantalum, niobium, vanadium, and combinations of any of the foregoing and optionally but preferably a source of halide ions. The composition and process are useful in increasing the adhesion of metal surfaces to polymeric substances and in preserving said adhesion through temperature variation.

Abstract: This invention relates to a method of forming a substrate with preparing a surface capable of making a cocontinuous bond comprising the steps of 1) obtaining a copper or copper alloy substrate and 2) applying an etching composition which comprises (a) an acid, (b) an oxidizing agent, (c) a copper complexing agent, and (d) a copper complex, wherein the copper complex is present in an amount which precipitates when applied to the copper or copper alloy substrate. The method also includes the step of 3) treating the substrate with a coating composition and/or 4) applying a stripping composition to the substrate. The invention also relates to copper articles, having surface porosity, including multilayer articles such as printed circuit boards and compositions used in the method. The present invention provides microporous copper or copper alloy substrates which have improved adhesion properties to organic material.

Abstract: The invention relates to a process, and compositions for its implementation, to promote adhesion between an inorganic substrate and an organic polymer, especially between the copper surfaces of printed circuits for electronic use and a polymer resin, in which an organometallic layer of a dark brown colour, which is very uniform and compact, is deposited on the inorganic substrate by means of treatment in a composition which comprises: a) a silane or a mixture of functional organic silanes with a structure represented by the following general formula: Y—(CH2)n—Si(OR)3 where: Y represents a functional organic group, n is a number which has a value between 0 and 3, and R represents a hydrogen atom or any easily hydrolysable group which is capable of releasing an atom of hydrogen b) an azole compound; c) an oxygen carrier; d) an organic or inorganic acid; and preferably e) a zinc compound.

Abstract: A micro-etching composition and a printed circuit board fabricated by using the micro-etching composition are provided. The micro-etching composition, comprising a main ingredient consisting of sulfuric acid and hydrogen peroxide and an assisting ingredient consisting of phenyltetrazole and a chloride ion source, can continuously treat the surface of copper and copper alloys to produce fine microscopic pits for improved adhesion to resins without producing a brown or black deposit. The printed circuit board exhibits excellent adhesion between inner layer circuit patterns and insulation resin layers, and is free from haloing.

Abstract: The present invention is to provide a hydrophilic treating method of the surface of metal comprising, the first process which treat the surface of metal with a chemical conversion solution to form a chemical conversion film on the metal surface while etching the metal surface and the second process which remove said film formed on the surface of metal to obtain rougher surface, and the final process which forms a hydrophilic film on the surface of metal. Desirably the surface roughness indicated by Rz after above mentioned second process is rougher than 1.5 &mgr;m.

Abstract: A method for producing a pinhole-free dielectric film comprising applying a photopolymer to a first dielectric surface of a dielectric film having pinholes, exposing a second and opposing surface to an amount of radiation effective to polymerize the photopolymer exposed by the pinholes, and removing unpolymerized photopolymer.

Abstract: Metal surfaces, particularly copper surfaces, which are oxidatively micro-etched to increase surface area through the use of molybdenum. The micro-etch solutions contain a proton source, e.g., a mineral acid, an oxidizer agent, e.g., hydrogen peroxide, an azole compound, and a molybdenum source.

Abstract: Multicurved copper films having fine-line elements suitable for radome applications can be improved by cutting the elements with reproducible precision to close tolerance (typically line widths of 3-10±0.25 mil) using an etchant comprising a concentrated saline solution of CuCl2.

Abstract: This invention relates to a method of forming a substrate with preparing a surface capable of making a cocontinuous bond comprising the steps of 1) obtaining a copper or copper alloy substrate and 2) applying an etching composition which comprises (a) an acid, (b) an oxidizing agent, (c) a copper complexing agent, and (d) a copper complex, wherein the copper complex is present in an amount which precipitates when applied to the copper or copper alloy substrate. The method also includes the step of 3) treating the substrate with a coating composition and/or 4) applying a stripping composition to the substrate. The invention also relates to copper articles, having surface porosity, including multilayer articles such as printed circuit boards and compositions used in the method. The present invention provides microporous copper or copper alloy substrates which have improved adhesion properties to organic material.

Abstract: A process for treating a copper or copper alloy substrate surface with a composition and corrosion inhibitor solution to minimize defect formation and surface corrosion, the method including applying a composition including one or more chelating agents, a pH adjusting agent to produce a pH between about 3 and about 11, and deionized water, and then applying a corrosion inhibitor solution. The composition may further comprise a reducing agent and/or corrosion inhibitor. The method may further comprise applying the corrosion inhibitor solution prior to treating the substrate surface with the composition.

Abstract: A method for treating a component made of a copper-based alloy containing lead. The component has Pb and Pb salts on a surface thereof. The method includes the step of etching the surface of the component selectively to remove almost entirely the Pb and Pb salts from the surface. The etching includes treating the surface with an acidic aqueous solution that is a) a non-oxidizing acidic aqueous solution of an acid capable of forming soluble Pb salts or b) an oxidizing acidic aqueous solution of an organic acid mixed with peroxide. The method also includes the step of passivating the etched surface whereby to inhibit release of any Pb or Pb salts remaining in the component when the passivated surface is in contact with water.

Abstract: A method of manufacturing electronic components includes disposing a top metal layer (502) comprised of solder over a bottom metal layer (201, 202) comprised of titanium or tungsten, and selectively etching the bottom metal layer (201, 202) over the top metal layer (502) with an etchant mixture (601) comprised of an etchant, an additive to control the temperature of the etchant mixture (601), and another additive to reduce the redeposition of the top layer (502).

Abstract: A process and composition for treating a metal surface to increase its surface roughness for subsequent adhesion to a polymer layer. The composition comprises hydrogen peroxide, inorganic acid, an amine free of a surfactant group and optionally, a corrosion inhibitor. The composition is characterized by elimination of a surfactant from solution.

Abstract: Coupling elements of a slide fastener or stringer thereof manufactured by cutting and forming a multiplicity of coupling elements from a linear material of copper or a copper alloy and fixing the coupling elements as spaced with a prescribed interval to the longitudinal edge of a fastener tape are immersed in an acidic treating liquid containing hydrogen peroxide, sulfuric acid, phosphoric acid, a surfactant, and an aliphatic alcohol to effect acid treatment thereby smoothing the outer surfaces of the coupling elements. The acid-treated outer surfaces of the coupling elements of the slide fastener or stringer thereof may be further subjected to a rustproofing treatment. The rustproofed outer surfaces of the coupling elements may be further subjected to a clear coating treatment. The acid-treated outer surfaces of the coupling elements may be further plated.

Abstract: A process for the treatment of brass components to reduce leachable lead therefrom when the components are exposed to water which includes the steps of first cleaning the brass components with a cleaning agent in the form of a mineral acid, a mineral acid plus an oxidizing agent, ammonium chloride or ferric chloride and then rinsing to remove the cleaning agent. Thereafter, the brass components are contacted with a lead removal reagent after which the brass components are washed again. It is also possible, in the preferred embodiment, to remove any leachable lead remaining on the surface of the brass components by the additional step of treating the brass components with a water soluble acid and thereafter rinsing the components to leave the components substantially free of the acid. The process as disclosed reduces the leachable lead to well within the most stringent state and/or federal guidelines.

Abstract: The present invention is a persulfate etchant composition especially useful for dissolving copper during fabrication of microelectronic packages. The etchant is characterized by its ability to selectively etch copper in the presence of nickel, nickel-phosphorous and noble metal alloys therefrom. Furthermore, no deleterious galvanic etching occurs in this etchant-substrate system so that substantially no undercutting of the copper occurs. The combination of high selectivity and no undercutting allows for a simplification of the microelectronic fabrication process and significant improvements in the design features of the microelectronic package, in particular higher density circuits. The persulfate etchant composition is stabilized with acid and phosphate salts to provide a process that is stable, fast acting, environmentally acceptable, has high capacity, and can be performed at room temperature. A preferred etchant composition is 230 gm/liter sodium persulfate, 3 volume % phosphoric acid and 0.

Abstract: A polishing composition comprising the following components:(a) an abrasive,(b) an oxidizing agent capable of oxidizing tantalum,(c) a reducing agent capable of reducing tantalum oxide, and(d) water.

Abstract: An electrolytically reclaimable etching solution for etching circuit boards and mold parts of copper and copper-based alloys, with a content of copper tetrammine sulfate, ammonia, ammonium sulfate, ammoniachloride, if necessary ammonium nitrate, and also a catalyzer for raising the etching rate. According to the invention, such an etching solution excels through a content of vanadium or a vanadium compound as a catalyzer in a concentration of 1 mg to 99 mg/l of etching solution, calculated as vanadium.

Abstract: A cleaner composition for removing from within a microelectronic fabrication a copper containing residue layer in the presence of a copper containing conductor layer, and a method for stripping from within a microelectronic fabrication the copper containing residue layer in the presence of the copper containing conductor layer. The cleaner composition comprises: (1) a hydroxyl amine material; (2) an ammonium fluoride material; and (3) a benzotriazole (BTA) material. The cleaner composition contemplates the method for stripping from within the microelectronic fabrication the copper containing residue layer in the presence of the copper containing conductor layer.

Abstract: The present invention advantageously provides a method for obtaining access to an integrated circuit chip encapsulated within a device package. The present method involves positioning a masking material, i.e., gasket, adjacent to the heat spreader of the device package. The gasket includes a cavity which is aligned adjacent a portion of the heat spreader directly above the chip. An etchant injection system is then placed against the gasket. A heat spreader etchant is then injected directly into the cavity such that the etchant contacts the exposed surface of the heat spreader. The etchant is supplied to the cavity until a opening is etched vertically through the thickness of the heat spreader. If the heat spreader is composed of copper plated with nickel, it is preferred that the etchant be a solution of 70% nitric acid heated to about 80.degree. C. Formation of the opening through the heat spreader may expose an adhesive layer.

Abstract: A method for planarizing an exposed metal surface on a substrate is provided in which surface irregularities are eliminated. A photoresist layer is first removed from the substrate. Then a conformal planarizing head is placed in contact with the metal surface while chemical etchant essentially free of abrasives is supplied to an interface between the metal substrate and the planarizing head. The surface is then planarized until it is free of irregularties.

Abstract: A process and composition for treating a metal surface to increase its surface roughness for subsequent adhesion to a polymer layer. The composition comprises hydrogen peroxide, inorganic acid, an amine free of a surfactant group and optionally, a corrosion inhibitor. The composition is characterized by elimination of a surfactant from solution.

Abstract: The present invention discloses a method for depositing a coating layer on an article without edge bead formation by integrating the steps of an edge bead rinsing process with a coating spin-out process such that an edge portion of the wafer can be efficiently cleaned with a cleaning solvent when the coating material is still in its liquid state. While the present invention method can be applied to any coating materials and to any coated substrate, it is particularly suitable for cleaning a spin-on-glass material from a semiconductor wafer such that the wafer edge is not coated with a SOG material and thus particulate contamination caused by cracked SOG from the wafer edge can be avoided.

Abstract: A microetching composition for copper or copper alloys comprising, (a) an oxidizing agent which can oxidize the copper or copper alloy, (b) a polymer compound which contains polyamine chains or a cationic group or both in the amount of 0.000001 to 1.0% by weight, and (c) 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 adaptable to the manufacture of printed wiring boards with highly integrated fine line patterns.

Abstract: A process for the treatment of brass components to reduce leachable lead therefrom when the component is exposed to water in which the brass component is first treated with an aqueous caustic solution to remove some of the leachable lead therefrom. Thereafter, the brass component is leached to remove excess caustic and then contacted with a water soluble carboxylic acid to remove most of the remaining leachable lead. It has been found that the efficiency of the process can be significantly enhanced through the use of ultrasonic agitation to ensure intimate contact between the treating solutions and the brass component. In the practice of the invention, the amount of lead removed is sufficient to meet the most stringent regulatory requirements for water quality.

Abstract: Copper foil having a matte surface and an opposite shiny surface, the shiny surface having thereon a protective metallic coating comprised of a first protective metallic layer, preferably iron, electrodeposited on the shiny surface and a second metallic layer, preferably zinc, electrodeposited on the first layer, the metallic coating be chemically removable without damage to the copper foil and the second metallic layer being softer than the first metallic layer. The matte surface of the copper foil can be bonded to a dielectric material, and the protective metallic coating can be removed from the shiny surface by etching.

Abstract: A process for etching the sides of a trace remove the feet which extend laterally out from the sides and over a circuit board substrate adjacent the trace.

Abstract: A method of using diluted nitric acid and an edge bead removal tool to remove copper from the perimeter of a semiconductor wafer is provided. In one embodiment, sensitive areas of the wafer are covered with photoresist, and the wafer perimeter cleared of photoresist, before the acid is applied. In another embodiment, sensitive areas of the wafer are protected with water spray as the copper etchant is applied. In a third embodiment, the nitric acid is applied to clear the wafer perimeter of copper before a chemical mechanical polishing (CMP) is performed on the layer of deposited copper. The excess thickness of copper protects copper interconnection structures from reacting with the copper etchant. All these methods permit copper to be removed at a low enough temperature that copper oxides are not formed. A semiconductor wafer cleaned of copper in accordance with the above-described method, and a system for low temperature copper removal is also provided.

Abstract: A technique for polishing an exposed surface of metal on a substrate to remove defects from mechanical working of metals, such as burrs and pigtails resulting from drilling, and defects from plating, such as nodules and depressions, is provided. The substrate has an exposed metal surface such as copper thereon which is to be treated to remove defects. A planarizing or polishing head, preferably a rotating roller, is provided which is continuously rotating with respect to the substrate, with the head in contact with the metal surface on the substrate. A chemical etchant, essentially free of abrasive material, is continuously supplied to the interface between the metal surface and the head. The treating and polishing continues until the defects have been removed or reduced to an acceptable value. In some instances where significant height reduction is required, thus requiring significant metal removal, several passes of the substrate may be required or a device with multiple heads may be used.

Abstract: The microetching and cleaning of copper clad substrates in printed wiring board production with solutions containing alkali metal persulfate and sulfuric acid is controlled to provide slower and more consistent copper etch rates by the presence of high proportions of alkali metal sulfate or an alkali metal sulfate/bisulfate mixture in the solutions, in a mole ratio of persulfate to sulfate or sulfate/bisulfate mixture of 1:0.1 to 1:10. When bisulfate is present with the sulfate, the sulfate will comprise at least about 10 mole % of the sulfate/bisulfate mixture. A surfactant may be present in the solutions to aid wettability on the copper clad substrates.

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: The present invention relates to a chemical etchant for etching metals in the presence of one or more metals not to be etched, the etchant comprising 10-25 gms EDTA, 15-35 gms K.sub.2 HPO.sub.4 and 25-45 gms oxalic acid in a liter of 30% H.sub.2 O.sub.2. More particularly, in the fabrication of interconnections for microchip structures, the present invention addresses the removal of intermediate adherent layers, e.g., Ti--W, without damaging other microchip structures made of other metals, such as Al or Al--Cu test pads; Cu and phased Cr--Cu layers; and Sn--Pb solder bumps. The use of potassium phosphate in the hydrogen peroxide+EDTA bath has been found to significantly reduce the attack on the metal not to be etched. Furthermore, the use of oxalic acid in the bath prevented the deposition of tin oxide on the substrate adherent layer metal, thus facilitating its complete removal.

Abstract: A method of metal-plating electrode portions of a printed-wiring board includes copper-plating the overall surface of the printed-wiring board on which an electric circuit has been formed, forming a metal plating resist coating on the copper plated wiring board except for on the electrode portions, and subjecting the electrode portions, which are not covered with the resist coating, to an electrolytic metal plating process, at least once, and then removing the remaining resist coating. The resist coating formation and the electrolytic metal plating process may optionally be repeated a predetermined number of times. An etching resist coating is then formed on the circuit portion including the electrode portions, and the copper-plated portion is then removed except from the circuit portion by etching and then stripping the etching resist coating.