Process for metallizing non-conductive substrates

A process for fully covering with an adherent essentially void-free metal layer the non-conductive surfaces of a through-hole formed in a printed circuit board substrate material comprised of glass-reinforced thermosetting or thermoplastic material, said process comprising the steps of:

• contacting said surfaces with a conditioning agent consisting essentially of an organosilane compound for a time sufficient to deposit said compound on said through-hole surfaces;
• depositing on the so-treated through-hole surfaces species catalytic to electroless metal deposition;
• and contacting the catalyzed through-hole surfaces with an electroless metal depositing solution to deposit metal fully and adherently and essentially void-free onto said catalyzed through-hole surfaces.

In a process for manufacturing printed circuit boards of the double-sided type in which a planar non-conductive substrate material comprised of a glass-reinforced thermosetting or thermoplastic material is provided with conductive circuit patterns on both sides thereof, and in which through-holes are provided through said non-conductive substrate, the surfaces of said through-holes being metallized to provide conductive interconnection between the conductive circuitry patterns on both sides of said substrate, the improvement comprising metallizing the surfaces of said through-holes by a process comprising the steps of:

• contacting said surfaces with a conditioning agent consisting essentially of an organosilane compound for a time sufficient to deposit said compound on said surfaces;
• depositing on the so-treated surfaces species catalytic to electroless metal deposition;
• and contacting the catalyzed through-hole surfaces with an electroless depositing solution to deposit metal fully and adherently and essentially void-free onto said catalyzed through-hole surfaces.

In a process for manufacturing printed circuit boards of the multi-layer type, in which a planar composite substrate material is provided comprised of a laminate of alternating parallel layers of metal and non-conductive, glass-reinforced thermosetting or thermoplastic material, and in which through-holes are provided through said composite substrate, the surfaces of said through-holes being metallized to provide conductive interconnection among metal portions of said composite substrate, the improvement comprising metallizing the surfaces of said through-holes by a process comprising the steps of:

• contacting said surfaces with a conditioning agent consisting essentially of an organosilane compound for a time sufficient to deposit said compound on said surfaces;
• depositing on the so-treated surfaces species catalytic to electroless metal deposition;
• and contacting the catalyzed through-hole surfaces with an electroless metal depositing solution to deposit metal fully and adherently and essentially void-free onto said catalyzed through-hole surfaces.

In a process for manufacturing printed circuit boards of the multi-layer type, in which a planar composite substrate material is provided comprised of a laminate of alternating parallel layers of metal and non-conductive, glass-reinforced thermosetting or thermoplastic material, and in which through-holes are provided through said composite substrate, the surfaces of said through-holes being first subjected to a desmearing process and then metallized to provide conductive interconnection among metal portions of said composite substrate, the improvement comprising metallizing the surfaces of said desmeared through-holes by a process comprising the steps of:

• contacting said surfaces with a conditioning agent consisting essentially of an organosilane compound for a time sufficient to deposit said compound on said surfaces;
• depositing on the so-treated surfaces species catalytic to electroless metal deposition;
• and contacting the catalyzed through-hole surfaces with an electroless metal depositing solution to deposit metal fully and adherently and essentially void-free onto said catalyzed through-hole surfaces.

A process for providing a full-coverage, essentially void-free, adherent metal layer on the surface of a non-conductive material, said surface consisting of the surface of a through-hole formed in a printed circuit board substrate material comprised of a glass-reinforced thermosetting or thermoplastic material, said process comprising the steps of:

• contacting said surface with a conditioning agent consisting essentially of an organosilane compound for a time sufficient to deposit said compound on said surface;
• depositing on the so-treated surface species catalytic to electroless metal deposition;
• and contacting said catalyzed surface with an electroless metal depositing solution to deposit metal fully and adherently and essentially void-free onto said catalyzed surface, wherein said organosilane compound is selected from the group consisting of aminoalkylsilanes, vinylsilanes, ureidoalkylsilane esters, epoxyalkylsilanes, and methacryloalkylsilane esters.