Patent ID: 6196871
Filing Date: 2001-03-06
Classification: H01R,H05K,Y02P

Abstract:
A method for mounting a ball-grid-array (BGA) electrical socket to a circuit board, said electrical socket and circuit board having different coefficients of thermal expansion (CTE), said method comprising the steps of:(a) manufacturing an electrical socket and a circuit board, a plurality of contacts received in the electrical socket, a plurality of contact pads formed on the circuit board corresponding to the contacts of the electrical socket, a plurality of holes defined in the electrical socket surrounding the contacts, and a plurality of positioning holes defined in the circuit board and corresponding to the holes of the electrical socket;(b) planting a plurality of solder balls onto the corresponding contacts of the electrical socket;(c) disposing a plurality of posts made of adhesive fusible material into the holes of the electrical socket and the positioning holes of the circuit board; and(d) subjecting the electrical socket and the circuit board to a heat treatment process to cause the solder balls of the electrical socket to be soldered to the contact pads of the circuit board and the posts to melt and then solidify to fix the electrical socket to the circuit board, said posts absorbing most of fracture stress exerted on the solder balls by the socket and the circuit board due to the different CTEs of the electrical socket and the circuit board thereby preventing misalignment between the contacts of the electrical socket and the contact pads of the circuit board.