Abstract: Recycled slurry is continuously blended with the slurry in use to provide a consistent polishing rate while consuming or discarding a small fraction of the slurry flowing continuously across the polishing pad. The slurry is recovered in a catch ring and fed to a recycle loop to blend the recovered slurry with fresh slurry, rejuvenating chemicals, or water; test the blend; filter the blend; and return the blend to the polishing pad. The volume returned to the pad slightly exceeds the volume recovered, causing the catch ring to overflow. Rinse water is recycled in the same fashion to keep the polishing pad wet between polishing cycles.

Abstract: The invention relates to a method and an apparatus for polishing an object by CMP with use of a polishing liquid. A change point of the temperature of a surface-to-be-polished of the object at the time of polishing is detected on the basis of information on the temperature of the surface-to-be-polished of the object, which information is obtained in advance at the time of polishing. An end point of the polishing of the object is detected on the basis of information on the change point. The object and a reference object are interlocked and simultaneously polished by a common polishing body, the degree-of-polishing of the reference object is monitored, and the degree-of-polishing of the object is detected on the basis of the degree-of-polishing of the reference object.

Abstract: Recycled slurry is continuously blended with the slurry in use to provide a consistent polishing rate while consuming or discarding a small fraction of the slurry flowing continuously across the polishing pad. The slurry is recovered in a catch ring and fed to a recycle loop to blend the recovered slurry with fresh slurry, rejuvenating chemicals, or water; test the blend; filter the blend; and return the blend to the polishing pad. The volume returned to the pad slightly exceeds the volume recovered, causing the catch ring to overflow. Rinse water is recycled in the same fashion to keep the polishing pad wet between polishing cycles.

Abstract: A process for control of recycle of ammoniacal copper etchant which uses metallic aluminum to remove copper without substantially adding undesirable byproducts, by controlling the temperature and mixture rate of the removal process. The very rapid reaction can be controlled by using a diluent of copper-free etchant, heating to process temperature, then adding spent, copper containing etchant at a controlled rate while actively cooling the system to control the temperature. The copper concentration can be monitored by colorimetry while maintaining the pH above pH 8. The separated metallic copper and aluminum hydroxide sludge are easily filtered from the etchant. The purified etchant is now suitable for chemical adjustment and reuse.

Abstract: A method of improved control of recycle of ammoniacal copper etchant which uses metallic aluminum to remove copper without substantially adding undesirable byproducts. The very rapid reaction can be controlled by using a diluent of copper-free etchant, eliminating overheating. The separated copper and aluminum hydroxide sludge are easily filtered from the etchant. The purified etchant is now suitable for chemical adjustment and reuse.

Abstract: A metal dissolving liquid and method for stripping tin and solder coatings, including the underlying tin-copper alloy, from the copper substrate of a printed circuit board. The liquid includes an aqueous solution of nitric acid in an amount sufficient to dissolve solder and tin, a source of ferric ions in an amount sufficient to dissolve tin-copper alloy, a source of halide ions in an amount sufficient to solubilize tin, an effective amount of methylsulfonic acid as promoter for complete stripping, and a source of an organic, water soluble amine. The combination of ingredients will substantially eliminate sludge formation, reduce attack on the copper substrate and provide a bright copper finish after solder removal. A liquid further including organic triazoles including benzotriazole in amounts not more than about 5% by weight and sulfamic ions in amounts not more than about 2.5% by weight.

Abstract: This invention relates to the removal of lead from spent ferric nitrate based solder strippers, the regeneration of the spent ferric nitrate based solder strippers, and the reuse of these solutions at least one time. It comprises a method and process for precipitating lead salts from used acidic solder strippers which are employed to strip solder coatings, including the underlying tin-copper alloy, from the copper substrate of a printed circuit board. The method includes the use of sulfate ions which are directly added to an aqueous solution of spent solder stripper, without neutralization of the spent solder stripper, optionally in combination with nitric or methylsulfonic acid addition. After precipitation and removal of the lead salts, additional components of the solder stripper composition may be added to substantially restore the initial functioning of the solder stripper.

Abstract: An electroless silver plating solution comprises a silver(I) complex, a thiosulfate salt, and a sulfite salt. This electroless silver plating solution uses a novel reducing agent combination of thiosulfate and sulfite. It shows a plating rate and a plating solution stability far superior to those of conventional silver plating solutions containing formaldehyde, reducing sugars, borohydride, hydrazine, and other reducing agents.

Abstract: An electroless silver or gold plating solution comprising a noncyanide metal complex, a thiosulfate, a sulfite, and at least one amino acid. These electroless plating solutions containing an amino acid exhibit an accelerated plating rate compared to identical solutions lacking amino acids.

Abstract: The use of aluminum sulfate to neutralize alkaline solutions yields a gelatinous precipitate. When neutralization of the solution causes other materials to precipitate along with the gel, filtration of the precipitated materials is very difficult because of the gel. The addition of water soluble magnesium, aluminum, and/or calcium salts as primary neutralizing agents for an alkaline stripper solution of a photoresin, followed by the acidification of the resulting slurry to a pH of from about 2 to about 3 gives a slurry of the precipitated resin which may be filtered quickly.

Abstract: An electroless gold plating solution comprising a gold(I) complex, a thiosulfate, a sulfite, a pH regulator and an oxidation controller. The electroless gold plating solution uses a novel reducing agent system, the thiosulfate-sulfite-sulfate system. It shows a plating rate and a plating solution stability comparable to those of conventional gold plating solutions containing borohydride, thiourea, hydrazine, and other reducing agents.

Abstract: This invention relates to electroless nickel plating of metals which are normally noncatalytic for electroless nickel initiation. It is especially useful in the electronics industry, such as for production of electroless nickel/electroless gold tabs or surface mount pads on printed circuit boards, and for use in electroless nickel plating over copper for radiofrequency interference shielding. More particularly, it comprises ammonium halide salt solutions of a palladium salt with another Group VIII precious metal salt and acid and optionally an alkali halide salt for effectively and completely catalyzing the initiation of electroless nickel plating on copper substrates.

Abstract: An improved method for rapidly stripping solder or tin from a substrate, such as copper, without adversely affecting the substrate. This is especially useful in the preparation of printed circuit boards. The composition comprises an acidic solution of an iron salt, a nitrate, at least one complexing agent such as gluconate, citrate, or EDTA, and at least one acid source. The acid source can comprise any mixture of compatible mineral and organic acids in any combination. The organic acids can include soluble aliphatic, substituted aliphatic, aromatic, or mixed acids. The mixture should be substantially free of halides and sulfates. This highly stable, rapid stripping rate formulation gives no attack on exposed glass fibers or epoxy printed circuit laminate material. It can operate over a wide temperature range without needing close temperature control.

Abstract: This invention relates to electroless nickel plating of metals which are normally noncatalytic for electroless nickel initiation. It is especially useful in the electronics industry, including production of electroless nickel/electroless gold tabs or surface mount pads on printed circuit boards, and for use in electroless nickel plating over copper for radiofrequency interference shielding. More particularly, it comprises alkali halide salt solutions of a palladium salt with another Group VIII precious metal salt in an inorganic acid solution for effectively and completely catalyzing the initiation of electroless nickel plating on copper substrates.

Abstract: The use of aluminum sulfate to neutralize alkaline solutions yields a gelatinous precipitate. When neutralization of the solution causes other materials to precipitate along with the gel, filtration of the precipitated materials is very difficult because of the gel. When the combination of magnesium sulfate and aluminum sulfate is used as the neutralizing agent for an alkaline stripper solution of a photoresin, the voluminous sludge may be filtered quickly.

Abstract: A forced air, ambient temperature, evaporator coupled to an electroless copper plating bath and to a purification system for replenishing and maintaining the stability of the plating bath, which bath tends to become depleted as the result of the reduction of water soluble cupric salt in an alkaline solution under copper plating and reducing conditions and in which the rate of evaporation of water from the surface thereof is insufficient to preclude growth in the volume thereof resulting from liquid additions thereto required to replace consumed constituents, thus giving rise to a need for bailout to prevent overflow thereof, solves the following problems: evaporation is independent of plating bath geometry; very high evaporation rates enable bailout to be zero at all plating loadings and plating thicknesses; the high evaporation rates provide sufficient cooling whereby the electroless copper solution can be introduced directly to the purification system with no additional cooling; dragout losses may be comple

Abstract: An improved electrodialysis stack and method of making the same wherein the border surface areas of the flow spacer frames are microroughened, as by chemical etching, sandblasting, with a patterned mold or embossing, the peripheral inner edges of the frame border are machined smooth, the microroughened border surface areas are coated with a thin layer of inert grease such as silicone, and placed under pressure with other electrodialysis components to form a closed system closely packed and essentially solid stack which is free from cross leakage between compartments and seepage therefrom.

Abstract: An electroless copper plating bath is improved so as to facilitate its regeneration in an electrodialysis cell. The bath includes elevated amounts of an added salt, preferably as Na salt. The elevated sodium ion level serves as additional counter-cation to hydroxyl ion which is produced at the cathode of the electrodialysis cell. The excess anion from the added salt increases the rate of out-migration of by-products, such as formate ions and sulfate ions, relative to hydroxyl ions through an anion permselective membrane.

Abstract: A forced air, ambient temperature, evaporator coupled to an electroless copper plating bath and to a purification system for replenishing and maintaining the stability of the plating bath, which bath tends to become depleted as the result of the reduction of water soluble cupric salt in an alkaline solution under copper plating and reducing conditions and in which the rate of evaporation of water from the surface thereof is insufficient to preclude growth in the volume thereof resulting from liquid additions thereto required to replace consumed constituents, thus giving rise to a need for bailout to prevent overflow thereof, solves the following problems: evaporation is independent of plating bath geometry; very high evaporation rates enable bailout to be zero at all plating loadings and plating thicknesses; the high evaporation rates provide sufficient cooling whereby the electroless copper solution can be introduced directly to the purification system with no additional cooling; dragout losses may be comple

Abstract: A method is provided for regenerating the spent permanganate ions in an alkaline permanganate-containing etchant composition by adding to the composition an oxidizer selected from the group consisting of an inorganic bromate, hypochlorite, chlorite, chlorate, peroxydisulfate, monopersulfate and mixtures thereof.