Thick film circuit resistant to scratching and solvent - produced from solventless paste of conductor particles and radiation curable resin binder

摘要

Thick film circuit consists of an (organic) substrate (I) coated with a circuit of electrically conductive particles (II) and a resin binder (III), which is cured by radiation after application. Pref. (I) is a polyester film and (III) an acrylated prepolymer cured by electron radiation. Circuit is applied to (I) in the form of a paste of (II) and (III) prepolymer and/or monomer in a thickness of max. 100 mu, pref. by screen printing, and cured cold by electrons with energies of 140-250(150) keV under normal atmos. conditions. It is tempered after and pref. also before cure, pref. for 1 min to 3 h at 40-200 degrees C, esp. for 2 min at 150 degrees C before and 1 min at 150 degrees C after cure. Conductivity can be reduced by irradiating again after tempering. Use of solvents and high baking temps. is avoided and the circuits are resistant to scratching and solvents.