Phenolic resin, useful for the production of epoxy resin systems for the encapsulation of semi-conductor devices, is prepared by reaction of an aromatic dihydroxyl compound with a phenol compound

摘要

A phenolic resin is prepared by reaction of an aromatic dihydroxyl compound with a phenol compound whereby the compound is terminated by structural units originating from the phenol compound and has a mol. wt. comprising the total mol. wt. of 2 moles of dihydroxyl compound and 3 moles of phenol compound minus the mol. wt. of 4 moles as analyzed by HPLC. A phenolic resin (I) is prepared by reaction of a dihydroxyl compound of formula (1) with a phenol compound whereby the compound (a) has a peak area of 90-100% (with respect to the total peak area) when measured by high performance liquid chromatography (HPLC) using a UV-detector (220 nm) and the compound (a) has a molecular structure terminated by structural units originating from the phenol compound, a mol. wt. comprising the total mol. wt. of 2 moles of dihydroxyl compound and 3 moles of phenol compound minus the mol. wt. of 4 moles of water and compound (b) has a molecular structure terminated by structural units originating from the phenol compound, a mol. wt. comprising the total mol. wt. of 2 moles of dihydroxyl compound and 2 moles of phenol compound minus the mol. wt. of 4 moles of water. Ar = 6-20C aromatic; R1-R4 = H, 1-20C alkyl, 5-20C cycloalkyl or 7-20 C aralkyl with the proviso that not both R1 and R3 and H and not both R2 and R4 are H Independent claims are included for: (1) a process for the production of the phenolic resin (I) by partial dehydration of the dihydroxyl compound followed by reaction with the phenol compound in a molar ratio of 40:100-90:100; (2) an epoxy resin (II) prepared by glycidyl etherification of the phenol resin (I); (3) an epoxy resin composition (III) prepared by mixing the epoxy resin (II), a hardener having hydroxyphenol groups and inorganic filler; (4) an encapsulated semiconductor device prepared by hardening of the composition (III).