Patent ID: 6524888
Filing Date: 2003-02-25
Classification: H01L

Abstract:
A method of attaching a semiconductor chip in a solder-effected connection to a substrate consisting of a conformal chip carrier, the semiconductor chip comprising a flip chip having an array of joining material bumps consisting of solder balls attached to said flip chip with a controlled collapse chip connection (C4) process, the substrate having an array of conductive pads corresponding to the array of joining material bumps, the method comprising:providing a fixture comprising a body having a first cavity for containing the semiconductor chip and a second cavity in communication with the first cavity for containing the substrate, placing the substrate over the semiconductor chip with the conductive pads opposing and in contact with the joining material bumps, such that during reflow of the joining material bumps, at elevated temperatures commensurate with the type of solder utilized, causing the weight of the substrate to act against the joining material bumps and aid in the attachment of the semiconductor chip to the substrate to form electrical connections therebetween, and removing said fixture upon completion of said electrical connections between said semiconductor chip and said substrate.