Abstract: A method of making a flip chip package that maintains flatness over a wide temperature range and provides good heat dissipation is described. A laminate substrate is electrically connected to electrical contacts disposed on a chip and underfill material is applied between the soldered connections. A body, for example an uncured dielectric material, is applied to the chip, the laminate substrate, a thermally conductive member or combinations thereof, and thermally conductive member is disposed adjacent to the surface of the chip that is opposite the surface connected to the laminate substrate. The body is extruded between the chip and the thermally conductive member. The thickness of the thermally conductive member is determined by balancing the stiffness and the CTE of both the thermally conductive member and the laminate substrate, and the length and width of the thermally conductive member may vary but are at least the size of the corresponding length and width of the chip.

Abstract: A method for forming a flip-chip-on-board assembly. An integrated circuit (IC) chip having a polyimide passivation layer is joined to a chip carrier via a plurality of solder bumps which electrically connect a plurality of contact pads on the IC chip to corresponding contacts on the chip carrier. A space is formed between a surface of the passivation layer and a surface of the chip carrier. A plasma is applied, to chemically modify the surface of the chip carrier and the passivation layer of the IC chip substantially without roughening the surface of the passivation layer. The plasma is either an O2 plasma or a microwave-generated Ar and N2O plasma. An underfill encapsulant material is applied to fill the space. The plasma treatment may be performed after the step of joining. Then, the chip and chip carrier are treated with the plasma simultaneously. Alternatively, the IC chip and chip carrier may be treated with the plasma before they are joined to one another.

Abstract: A method for forming a flip-chip-on-board assembly. An integrated circuit (IC) chip having a polyimide passivation layer is joined to a chip carrier via a plurality of solder bumps which electrically connect a plurality of contact pads on the IC chip to corresponding contacts on the chip carrier. A space is formed between a surface of the passivation layer and a surface of the chip carrier. A plasma is applied, to chemically modify the surface of the chip carrier and the passivation layer of the IC chip substantially without roughening the surface of the passivation layer. The plasma is either an O2 plasma or a microwave-generated Ar and N2O plasma. An underfill encapsulant material is applied to fill the space. The plasma treatment may be performed after the step of joining. Then, the chip and chip carrier are treated with the plasma simultaneously. Alternatively, the IC chip and chip carrier may be treat with the plasma before they are joined to one another.

Abstract: A method of making a flip chip package that maintains flatness over a wide temperature range and provides good heat dissipation is described. A laminate substrate is electrically connected to electrical contacts disposed on a chip and underfill material is applied between the soldered connections. A body, for example an uncured dielectric material, is applied to the chip, the laminate substrate, a thermally conductive member or combinations thereof, and thermally conductive member is disposed adjacent to the surface of the chip that is opposite the surface connected to the laminate substrate. The body is extruded between the chip and the thermally conductive member. The thickness of the thermally conductive member is determined by balancing the stiffness and the CTE of both the thermally conductive member and the laminate substrate, and the length and width of the thermally conductive member may vary but are at least the size of the corresponding length and width of the chip.

Abstract: A method for forming a flip-chip-on-board assembly. An integrated circuit (IC) chip having a polyimide passivation layer is joined to a chip carrier via a plurality of solder bumps which electrically connect a plurality of contact pads on the IC chip to corresponding contacts on the chip carrier. A space is formed between a surface of the passivation layer and a surface of the chip carrier. A plasma is applied, to chemically modify the a surface of the chip carrier and the passivation layer of the IC chip substantially without roughening the surface of the passivation layer. The plasma is either an O.sub.2 plasma or a microwave-generated Ar and N.sub.2 O plasma. An underfill encapsulant material is applied to fill the space. The plasma treatment may be performed after the step of joining. Then, the chip and chip carrier are treated with the plasma simultaneously. Alternatively, the IC chip and chip carrier may be treated with the plasma before they are joined to one another.