Methods for Metal Bump Die Assembly

A method, comprising:

• providing a substrate core having a plurality of die attach regions on a die side surface each for receiving an integrated circuit, and having regions outside the die attach regions;
• forming conductive traces on the substrate core, the conductive traces exposed in the die attach regions for coupling to conductive terminals of an integrated circuit die to be flip chip mounted in each die attach region;
• receiving a plurality of integrated circuit dies, each having a plurality of conductive terminals for flip chip mounting to the substrate core, each conductive terminal having solder deposited on at least an end portion;
• aligning an integrated circuit die of the plurality of integrated circuit dies with each die attach region on the substrate, and bringing the solder deposited on the end portion of the conductive terminals into physical contact with the conductive traces;
• and
• performing a thermal reflow of the solder deposits by selectively heating the plurality of integrated circuit dies to a temperature sufficient to melt the solder deposits, without heating the substrate above a temperature of 180 degrees Celsius.

A method, comprising:

• forming a solder deposit on an least an end portion of a plurality of conductive terminals of each of a plurality of integrated circuit dies;
• providing a substrate having die attach regions for flip chip mounting of the integrated circuit dies to a die side of the substrate, and having conductive traces disposed in the die attach regions and corresponding to the conductive terminals of the integrated circuit dies, and having cover material over the die side of the substrate outside of the die attach regions;
• and
• disposing one of the plurality of integrated circuit dies in each die attach region, bringing the solder deposits into contact with the conductive traces and selectively heating the integrated circuit dies to melt the solder deposits, and forming an electrical connection and a physical solder connection between the conductive terminals and the conductive traces.