MACRO-DEFECT-FREE Cements for Electronic Packaging
Original Publication Date: 1989-May-01
Included in the Prior Art Database: 2005-Jan-28
The features of this disclosure are: (a) the possibility of using MACRO-DEFECT-FREE (MDF) cements for electronic packaging, and (b) improving their properties for use at high humidities by impregnation with a hydrophobic monomer and in-situ polymerization. The recently discovered MDF cements [1, 2, 3], based on ordinary Portland or calcium aluminate cements, but using a hydrophilic polymer as an additive, e.g., partially hydrolyzed polyvinylacetate, and shear mixing, have much higher tensile strength and toughness and lower permeability than ordinary cements. They have the added advantage of low temperature processing and easy forming, when compared to ceramics. They have high electrical strength (8.7 kV/mm) and, in dry atmospheres, have low dielectric constant (8-9 at 1 MHz), low loss factor (0.01-0.