摘要:
Simultaneous non-contact plating and planarizing of copper interconnections in semiconductor wafer manufacturing is performed by providing relative motion between a bipolar electrode and a metallized surface of a semiconductor wafer without necessary physical contact with the wafer or direct electrical connection thereto.
摘要:
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.
摘要:
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.
摘要:
An electrophotographic system is described in which a photoconductive ion modulator screen is used in conjunction with an anodized aluminum dielectric imaging surface. This combination enables the steps of image transfer and fixing to be carried out simultaneously without destroying the latent image produced on the dielectric imaging surface.A duplex anodized aluminum coating is prepared by forming a porous aluminum oxide layer by electrolytically oxidizing an aluminum surface and thereafter continuing the electrolytic oxidation under conditions which produce a barrier type aluminum oxide layer. The resulting duplex anodized aluminum coating containing both porous type aluminum oxide and barrier type aluminum oxide is used as the dielectric imaging surface in this electrophotographic system.
摘要:
An electrophotographic system is described in which a photoconductive ion modulator screen is used in conjunction with an anodized aluminum dielectric imaging surface. This combination enables the steps of image transfer and fixing to be carried out simultaneously without destroying the latent image produced on the dielectric imaging surface.A duplex anodized aluminum coating is prepared by forming a porous aluminum oxide layer by electrolytically oxidizing an aluminum surface and thereafter continuing the electrolytic oxidation under conditions which produce a barrier type aluminum oxide layer. The resulting duplex anodized aluminum coating containing both porous type aluminum oxide and barrier type aluminum oxide is used as the dielectric imaging surface in this electrophotographic system.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
A tin-palladium catalyst useful for electroless deposition of metals, such as copper or nickel, onto a nonconductive substrate, said catalyst containing a much lower concentration of halide ions than similar compositions presently known, or being completely free of halide ions. The tin-palladium catalyst can be prepared from nonhalide salts using a hydroxy substituted organic acid to stabilize the system.
摘要:
An electroless plating catalyst prepared by reacting a tin salt in the molten state with a precious metal complex. The final catalyst may be a solid or a liquid at room temperature, depending upon the reaction conditions, and it can be reconstituted by dilution with an appropriate aqueous solution to prepare or replenish catalytic working baths for electroless plating. Examples include the molten salt reaction of precious metal complexes with anhydrous stannous chloride or stannous chloride dihydrate.