Plasma-Treated Heat Spreader Surface for FCBGA-H TIM Adhesion

The patent applies local quality by treating only the surface of the heat spreader that contacts the TIM with plasma treatment, while the bulk material remains nickel-plated copper for thermal conductivity. This creates different properties in different regions: the bulk maintains thermal performance while the surface gains adhesion properties through plasma-induced roughness and chemical activation.

The plasma treatment changes the physical and chemical parameters of the heat spreader surface. The surface roughness increases, chemical composition changes (creation of carbon-oxygen bonds and activated groups), and surface energy increases. These parameter changes enhance adhesion without altering the bulk thermal conductivity properties of the nickel-plated copper material.

The plasma treatment is applied as a preliminary action before TIM deposition. By pre-treating the heat spreader surface with plasma to create the desired roughness and chemical activation, the subsequent TIM deposition process becomes simpler and more effective. This preliminary preparation prevents adhesion problems before they occur rather than requiring complex post-processing.

The patent replaces mechanical surface preparation methods (such as abrasion or chemical etching) with plasma treatment. Plasma provides a cleaner, more controllable, and environmentally friendly approach to surface modification. The plasma process uses ionized gas to achieve surface activation without the mechanical complexity or waste associated with traditional methods.