Abstract: The present invention is a method for cleaning the cavities in electronic components by providing a semiconductor component having an outside surface and a cavity therein. The component including hole in the outside surface enabling fluid flow in to or out of the cavity. The component is immersed in a solvent bath where solvent is flowed into the cavity using the hole, the solvent cleaning the cavity and then optionally being evacuated from the cavity. Specifically, the principles of the present invention may be used to clean the underfill space of a flip-chip package. The flip-chip package includes a packaging substrate with an evacuation port passing through the bulk of the packaging substrate such that the port is in communication with the underfill space and a bottom surface with the packaging substrate. This assembly is immersed in a solvent filled solvent bath. Solvent is drawn into the underfill space through said port. Alternatively, solvent may be injected into the underfill space through the port.

Abstract: A TAB device (10) is coupled to a circuit board (12). The TAB device (10) includes a semiconductor die (11) having leads (18) extending therefrom. A material layer (30), typically a polyimide layer, covers the inward portion of the leads (18) to maintain leading position during attachment of the TAB device (10) to the circuit board (12). Prior to attachment, a backside encapsulation region (40) is applied to the backside of the TAB device (10), sealing the backside of the leads (18). The backside encapsulation material is selected to have a coefficient of thermal expansion similar to the coefficient of thermal expansion of the first material layer (18). The backside encapsulation material is selected to have a coefficient of thermal expansion similar to the coefficient of thermal expansion of the first material layer (30), to prevent excessive warpage.

Abstract: A TAB device (10) is coupled to a circuit board (12). The TAB device (10) includes a semiconductor die (11) having leads (18) extending therefrom. A material layer (30), typically a polyimide layer, covers the inward portion of the leads (18) to maintain leading position during attachment of the TAB device (10) to the circuit board (12). Prior to attachment, a backside encapsulation region (40) is applied to the backside of the TAB device (10), sealing the backside of the leads (18). The backside encapsulation material is selected to have a coefficient of thermal expansion similar to the coefficient of thermal expansion of the first material layer (18). The backside encapsulation material is selected to have a coefficient of thermal expansion similar to the coefficient of thermal expansion of the first material layer (30), to prevent excessive warpage.

Abstract: A method for assembly of bare silicon die onto flexible or thin laminate substrates that minimizes substrate and die warpage induced after underfill cure operations and at the same time reduces the cycle time for the assembly process. More specifically, an opposing layer of thermoset component is adhered to a balance plate (metal) or other material with applicable coefficient of thermal expansion "CTE" and modulus of elasticity on the top of the die. The offsetting layer of material causes the die to warp to the other side and as a result the two self opposing warpage effects neutralize themselves.