International Business Machines Corporation

Jean Dery

Luis Jesus Matienzo

Frank Daniel Egitto

David L Questad

William John Rudik

Son K Tran

Luc Ouellet

Charles Ouellet

Michael A Gaynes

Eric A Johnson

James Robert Wilcox

David V Caletka

Eric Duchesne

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.

Thermally enhanced and mechanically balanced flip chip package and method of forming

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 O plasma or a microwave-generated Ar and N 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. The plasma treatment improves adhesion between the encapsulant and the IC chip, and between the encapsulant and the chip carrier.

Flip chip assembly

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 O,plasma or a microwave-generated Ar and N,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 treat with the plasma before they are joined to one another. The plasma treatment improves adhesion between the encapsulant and the IC chip, and between the encapsulant and the chip carrier.

Method of forming a flip chip assembly, and a flip chip assembly formed by the method

Thermally enhanced and mechanically balanced flip chip package and

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. The plasma treatment improves adhesion between the encapsulant and the IC chip, and between the encapsulant and the chip carrier.

Method of forming a flip chip assembly

Growing community of inventors

Granby, Canada

Jean Dery