Abstract Printed circuit boards having a plurality of circuit layers are produced on a copper-clad substrate by first forming a pattern in a desired configuration to produce the first layer of the printed circuit board, then covering it with an energy-sensitive material comprising a rubber modified epoxy resin, an acrylated epoxy resin and a viscosity modifier; the energy-sensitive material is delineated in a desired pattern and developed to uncover portions of the underlying metallization pattern and the entire substrate is then blanket cured to produce a rigid layer having openings in appropriate places; the openings are metallized and a second copper pattern is produced on the cured polymer by conventional metallization and lithographic techniques. If desired, the process is repeated until a suitable number of copper patterned levels are obtained.
An energy sensitive material capable of curing under the influence of radiation comprises a non-rubber modified first epoxy resin wherein the terminal groups have been at least partially acrylated, a rubber modified second epoxy resin having a rubber in the backbone of the resin derived from reacting an epoxy resin with a carboxy terminated butadiene-acrylonitrile containing rubber and the terminal groups of which have been at least partially acrylated, said second epoxy resin being compatible with the first epoxy resin.
Claim 2
Dependent Claim
80 words
An energy sensitive material capable of curing under the influence of radiation comprises a non-rubber modified first epoxy resin wherein the terminal groups have been at least partially acrylated, a rubber modified second epoxy resin having a rubber in the backbone of the resin derived from reacting an epoxy resin with a carboxy terminated butadiene-acrylonitrile containing rubber and the terminal groups of which have been at least partially acrylated, said second epoxy resin being compatible with the first epoxy resin.
Claim 3
Dependent Claim
10 words
The composition recited in claim 1 including a viscosity modifier.
Claim 4
Dependent Claim
21 words
The composition recited in claim 1 wherein said first and second epoxy resins are termed from the diglycidyl ether of bisphenol-A.