Patent ID: 7416923

Claim:
A method comprising: forming as a sheet a first film portion of an underfill film, the first film portion having a poor thermal conductivity relative to a thermally conductive sheet of the underfill film, the first film portion being a resin material, the thermally conductive sheet being a thermally conductive graphite sheet; forming as a sheet a second film portion of the underfill film, the second film portion having the poor thermal conductivity relative to the thermally conductive sheet, the second film portion being a resin material; forming a plurality of holes within the thermally conductive sheet such that no holes are formed within the first film portion and within the second film portion, the holes formed by a stamping process; roughening a top surface and a bottom surface of the thermally conductive sheet to promote subsequent adhesion of the top and the bottom surfaces to the first and the second film portions of the underfill film; disposing the thermally conductive sheet onto the first film portion such that the thermally conductive sheet adheres to the first film portion; disposing the second film portion on the thermally conductive sheet, such that the thermally conductive sheet adheres to the second film portion, such that the thermally conductive sheet is sandwiched between the first and the second film portions, and such that the underfill film includes the first film portion, the thermally conductive sheet, and the second film portion, where the thermally conductive sheet has a coefficient of thermal expansion (CTE) substantially equal to a CTE of the underfill film, such that inclusion of the thermally conductive sheet within the underfill film does not affect a functionality of the underfill film to relax thermal stresses; applying the underfill film to a printed circuit board; applying the solder bumps to an electrical component; and, attaching the electrical component to the printed circuit board such that the underfill film is positioned between the electrical component and the printed circuit board, such that the solder bumps correspond to and are aligned to the holes within the thermally conductive sheet, and such that the solder bumps penetrate the first film portion and the second film portion of the underfill film, wherein presence of the thermally conductive sheet within the underfill film promotes greater heat dissipation from the electrical component as compared to where the thermally conductive sheet is not included within the underfill film.