Electrically high grade binder for printed circuit board - contg. bisphenol=A di:cyanate, bisphenol=A epoxide resin and opt. brominated bisphenol=A

摘要

Electrically high-grade binder for making PCB base boards consist of a one-component system based on bisphenol-A dicyanate (IA) or its prepolymer (IB) in a solvent (mixt.) such as ketones and/or aromatic hydrocarbons, e.g. acetone, MEK, cyclohexane, xylene and ethylene glycol. The novelty is that the binder consists of a combination of 100 (wt.) pts. (I) or its soln. with a B time (at 160 deg.C) of at least 4 h; 70-210 pts. bisphenol-A epoxide resin (combination) (II) or its soln. with an epoxide equiv. of 330-600 and readily hydrolysable Cl content of max. 0.1%; and 6.5-22 pts. bisphenol-A (IIIA) and/or tetrabromobisphenol A (IIIB) in the form of a 20-80% soln. Pref. the amts. used are 70-75 pts. (II) and 8-22 pts. (III). (IB) is used as 60-80% soln. in MEK. The (II) (combination) has low and medium mol. wt. and an epoxide equiv. of 330-430. It is used as 70-75% soln. in MEK. ADVANTAGE - The binder is suitable for making boards with a low, dielectric constant over a wide frequency range, without impairing other properties, e.g. good adhesion to Cu and storage stabilit