Abstract A process for producing conductive articles suitable for use as printed circuit boards is provided. These articles comprise an inner substrate having at least one ply of fibrous sheet material (glass fabric) impregnated with a polyimide resin, and a conductive metal such as nickel, copper or silver bonded to at least a portion of at least one surface of the inner substrate. The process comprises (1) electrolessly depositing an essentially continuous nickel/boron alloy coating on the conductive metal portion, the alloy having a boron content of from about 0.1 to 15 percent by weight, based on the weight of alloy, and (2) soldering the coated article. The electroless nickel/boron coating permits greater flexibility in soldering, especially when the article has been heated in air.
A PROCESS FOR MAKING A LAMINATED AND SOLDERED ARTICLE OF MANUFACTURE COMPRISING AN INNER SUBSTRATE HAVING AT LEAST ONE PLY OF FIBROUS SHEET MATERIAL IMPREGNATED WITH A CURED POLYMERIC PRECURSOR OF A POLYIMIDE RESIN, SAID RESIN BEING THE REACTION PRODUCT OF AN ANHYDRIDE COMPONENT AND AN AMINE COMPONENT, AND A CONDUCTIVE METAL BONDED TO AT LEAST A PORTION OF AT LEAST ONE SURFACE OF SAID INNER SUBSTRATE, SAID PROCESS COMPRISING (1) ELECTROLESSLY DEPOSITING AN ESSENTIALLY CONTINUOUS NICKEL/BORON ALLOY COATING ON SAID CONDUCTIVE METAL PORTION OF SAID ARTICLE, SAID ALLOY HAVING A BORON CONTENT OF FROM ABOUT 0.1 TO 15 PERCENT BY WEIGHT, BASED ON THE WEIGHT OF ALLOY, (2) HEATING SAID ARTICLE OF MANUFACTURE IN AN OXIDIZING ATMOSPHERE AT A TEMPERATURE OF AT LEAST ABOUT 215*C. FOR AT LEAST ABOUT ONE MINUTE, AND (3) SOLDERING THE COATED ARTICLE.
Claim 2
Dependent Claim
138 words
A PROCESS FOR MAKING A LAMINATED AND SOLDERED ARTICLE OF MANUFACTURE COMPRISING AN INNER SUBSTRATE HAVING AT LEAST ONE PLY OF FIBROUS SHEET MATERIAL IMPREGNATED WITH A CURED POLYMERIC PRECURSOR OF A POLYIMIDE RESIN, SAID RESIN BEING THE REACTION PRODUCT OF AN ANHYDRIDE COMPONENT AND AN AMINE COMPONENT, AND A CONDUCTIVE METAL BONDED TO AT LEAST A PORTION OF AT LEAST ONE SURFACE OF SAID INNER SUBSTRATE, SAID PROCESS COMPRISING (1) ELECTROLESSLY DEPOSITING AN ESSENTIALLY CONTINUOUS NICKEL/BORON ALLOY COATING ON SAID CONDUCTIVE METAL PORTION OF SAID ARTICLE, SAID ALLOY HAVING A BORON CONTENT OF FROM ABOUT 0.1 TO 15 PERCENT BY WEIGHT, BASED ON THE WEIGHT OF ALLOY, (2) HEATING SAID ARTICLE OF MANUFACTURE IN AN OXIDIZING ATMOSPHERE AT A TEMPERATURE OF AT LEAST ABOUT 215*C. FOR AT LEAST ABOUT ONE MINUTE, AND (3) SOLDERING THE COATED ARTICLE.
Claim 3
Dependent Claim
20 words
The process of claim 1 in which the soldering is carried out in the presence of a non-corrosive, rosin-based flux.
Claim 4
Dependent Claim
19 words
The process of claim 1 wherein said nickel/boron alloy is deposited to a thickness of at least 0.02 mil.
Claim 5
Dependent Claim
40 words
The process of claim 3 wherein the nickel/boron alloy has a boron content within the range of about 0.1 to 2 percent by weight and the coating is deposited to a thickness in the range of 0.02 to 5 mils.