Back to results
US 4,191,800 AGranted
Devices employing flexible substrates and method for making same
AssigneeBell Telephone Laboratories, Incorporated
InventorKenneth A. Holtzman
Life of this patent
Estimating the term…
Abstract
Processes and devices are described which employ flexible substrates made from cloth impregnated with a resin of a particular composition. The flexible substrate is made into double-clad printed wiring substrate for use in double-sided circuits. These substrates exhibit excellent dimensional stability during circuit fabrication and soldering as well as excellent flame retardance and electrical insulation resistance.
Claims8
A process for the fabrication of electronic circuits with flexible substrates comprising the steps of
- a. impregnating a cloth-mat material with an epoxy resin-hardener composition free from solvent,
- b. adhering a copper sheet to both sides of the impregnated cloth-mat material to form a double-sided clad flexible substrate,
- c. curing the double-sided clad flexible substrate by heating, characterized in that epoxy resin-hardener composition consists essentially of, in parts by weight,
- ______________________________________ Epoxy Resin 100 Antimony Oxide 0-80 Chlorinated Hydrocarbon Flame Retardant 0-160 Maleic Anhydride Adduct of Methylcyclopentadiene 68-95 Carboxy Terminated Butadiene-Acrylonitrile 69-107 2,4,6 tri(dimethylaminomethyl) Phenol 0.5-3.0 Antioxidant 0.1-6.0 ______________________________________
- and the impregnated cloth is cured at a temperature between 150 and 180 degrees C. for a time between 24 and 96 hours.
2 more elements
Dependencies are inferred from the claim text.