disclosed is a method of encapsulating integrated circuit chips formed on an insulating substrate which permits complete filling of areas under the chip . the encapsulant employed is a dispersion of a material , such as a silicone elastomer , which cures by reaction with water vapor . subsequent to application of the encapsulant over and under the chip , the solvent of the dispersion is evaporated during a pre - cure treatment by means of a dry ambient of less than 5 % relative humidity which suppresses crosslinking . after essentially all the solvent is thus removed , the encapsulant is cured by exposure to a second ambient of higher relative humidity which enhances crosslinking .