Patent ID: 6135791
Filing Date: 2000-10-24
Classification: H05K

Abstract:
An electrical connector assembly comprising a connector and a circuit board, said connector including a base plate fixed to the circuit board and a cover movably mounted to the base plate, the base plate defining contact receiving bores for receiving and retaining conductive contacts therein, the contacts being soldered to corresponding conductive pads formed on the circuit board by means of solder balls, the cover being adapted to retain an electronic device thereon, pins of the electronic device extending through holes defined in the cover and partially extending into the contact receiving bores whereby when the cover is moved with respect to the base, the pins are brought into contact with and thus electrically engage with the contacts the holes in the base plate having shape different than the shape of the bores, the base plate additionally defining a plurality of holes not having contacts therein, said holes being arranged in a particular pattern on the base plate, the base plate further being made of a dielectric material, said dielectric material being completely and uniformly distributed in the base plate and having a regular arrangement of molecules, said regular arrangement of molecules being achieved by means of injection molding the base plate with a mold comprising core pins whereby the base plate molded thereby defines the plurality of holes in the particular pattern, said pattern having been determined empirically to reduce, both by arrangement of said plurality of holes in the finished base plate and by promotion of said regular arrangement of molecules during the injection molding process, a difference between thermal expansion coefficients of the base plate in first and second directions substantially normal to each other.