Process for forming polyimide-metal laminates

The process of hydrophilizing a surface of a polyimide sheet which comprises contacting said sheet with a one-phase solution comprising between about 5 to 20 percent by weight of an amine of the formula:

• H.sub.2 N(CH.sub.2).sub.n NH.sub.2 by wherein n is an integer from 2 to 6, 25 and 50 percent by weight of an alkali metal hydroxide between about 5 and 20 percent by weight of a water miscible glycol of the formula:
• OH(CH.sub.2).sub.m OH wherein m is an integer from 2 to 4 and the remainder of the solution being water for a time, and at a temperature sufficient to render the surface uniformly and substantially completely hydrophilized.

The process for coating both surfaces of a polyimide sheet in the absence of an adhesive, said process comprising contacting said sheet with a one-phase diamine with the formula:

• H.sub.2 N--(CH.sub.2).sub.n NH.sub.2 wherein n is an integer from 2 to 6, an alkali metal hydroxide, a glycol of the formula OH(CH.sub.2).sub.m OH wherein m is an integer from 2 to 4 and water for a time, and at a temperature sufficient to render the said surfaces uniformly and substantially completely hydrophilized, treating said surfaces with a catalyst to create surfaces receptive to the electroless deposition of nickel or cobalt, depositing nickel or cobalt on said receptive surfaces by electroless deposition to form nickel or cobalt coated surfaces of said sheet, said deposited nickel or cobalt metal layers being electrically conductive, forming microcracks in each of said metal coatings, baking said polyimide sheet coated with said dual metal coatings containing microcracks to volatilize components in said polyimide sheet while avoiding delamination of said coatings and depositing copper on said metal coatings by electrolytic deposition to form exposed copper coatings on said polyimide sheet.

A process for coating at least one surface of a polyetherimide sheet with copper in the absence of an adhesive said process comprising contacting said sheet with a one-phase solution comprising a diamine with the formula:

• H.sub.2 N--(CH.sub.2).sub.n.sup..about. --NH.sub.2 wherein n is an integer between 2 and 6, an alkali metal hydroxide, a water miscible glycol of the formula:
• OH(CH.sub.2).sub.m OH wherein m is an integer from 2 to 4 and the remainder of the solution water for a time, and at a temperature sufficient to render at least one surface uniformly and substantially completely hydrophilized, treating said at least one surface with a catalyst to render at least one surface receptive to the electroless deposition of nickel or cobalt, depositing nickel or cobalt on said receptive surface by electroless deposition to form a nickel or cobalt coated surface on said sheet, said deposited nickel or cobalt metal layer being electrically conductive, and depositing copper on said nickel or cobalt metal layer by electrolytic deposition to form at least one exposed copper coating on said polyetherimide sheet.

The process of hydrophilizing a surface of a polyetherimide sheet which comprises contacting said sheet with a one-phase solution comprising between about 5 to 20 percent by weight of an amine of the formula H.sub.2 N--(CH.sub.2).sub.n --NH.sub.2 wherein n is an integer from 2 to 6, 25 and 50 percent by weight of an alkali metal hydroxide, between about 5 and 20 percent by weight of a water miscible glycol of the formula:

• OH(CH.sub.2).sub.m OH wherein m is an integer from 2 to 4 and the remainder of the solution water for a time, and at a temperature sufficient to render at least one surface uniformly and substantially completely hydrophilized.

A process for coating both surfaces of a polyetherimide sheet in the absence of an adhesive said process comprising contacting said sheet with a one-phase solution comprising a diamine with the formula:

• H.sub.2 N--(CH.sub.2).sub.n NH.sub.2 wherein n is an integer between 2 and 6, an alkali metal hydroxide, a glycol of the formula:
• OH(CH.sub.2).sub.m OH wherein m is an integer from 2 to 4 and water for a time, and at a temperature sufficient to render both surfaces uniformly and substantially completely hydrophilized, treating said surfaces with a catalyst to create surfaces receptive to the electroless deposition of nickel or cobalt, depositing nickel or cobalt on said receptive surfaces by electroless deposition to form a nickel or cobalt coated surfaces of said sheet, said deposited nickel or cobalt metal layer being electrically conductive, forming microcracks in each of said metal coatings, baking said polyetherimide sheet while avoiding delamination of said coatings and depositing copper on said metal coatings by electrolytic deposition to form exposed copper coatings on said polyetherimide sheet.

The process of claim 41 wherein nickel is electrolessly deposited.