International Business Machines Corporation

Tien Y Wu

David L Questad

James Robert Wilcox

William T Chen

Thomas P Gall

George Henry Thiel

Donna Jean Trevitt

Patrick Robert Zippetelli

Anne Marie Quinn

Sampath Purushothaman

Michael A Gaynes

Eric A Johnson

Luis Jesus Matienzo

David Noel Light

John Steven Kresge

Irving Memis

Bahgat Ghaleb Sammakia

Janusz S Wilczynski

James Spalik

William Tze-You Chen

Steven F Arndt

Lawrence S-w Mok

A chip package includes a die having an active surface and an inactive surface. An adhesive is formed on the inactive surface where the adhesive has a low Young's modulus of elasticity. The low Young's modulus of elasticity may be 10,000 psi or less; 1,000 psi or less; or, preferably, about 1,000 psi. Further, the adhesive may include a thermal conducting material. A protective plate is coupled to the inactive surface using the adhesive and a chip carrier is coupled to the active surface of the die.

Protective cover plate for flip chip assembly backside

The bond strength between a semiconductor chip and a metal heat sink in an integrated circuit package can be improved by using an adhesive system comprising two separate layers, one layer exhibiting preferential bonding strength for the chip and the other layer exhibiting preferential bonding strength for the metal heat sink.

Integrated circuit package

Integrated circuit package including a heat sink and an adhesive

A power/ground structure and associated circuit card or board are provided in which the coefficient of thermal expansion of the power/ground structure and associated circuit board are closely matched to each other. The circuit board or card is formed of organic electrically-insulating material having electrical circuitry thereon which carries an integrated circuit chip. The power/ground assembly is formed of alternating layers of organic insulating material and at least two layers of electrically-conducting material, typically copper, one of the layers of electrically-conducting material forming a power connection and another layer of the electrically-conducting material forming a ground plane. There is also at least one additional layer of a structural material having a relatively high Young's Modulus and a CTE of less than about 10 PPM/.degree.C. Invar or copper clad Invar are preferred materials for this structure. The electrically-conducting copper material and the Invar are selected in thickness and number such that, together with the electrically-insulating material, the composite CTE of the power/ground structure closely matches that of the circuit card or board.

Laminated electronic package including a power/ground assembly

The present invention provides a novel method for improving the adhesion of polymers, particularly adhesives, to nickel surfaces. The method involves contacting the nickel surface with a hydrogen peroxide solution having a temperature of at least about 40.degree. C. for a time sufficient to form a wettable oxide surface having a water contact angle of less than about 10.degree..

Method for improving the adhesion of polymeric adhesives to nickel

An electronic package having an active cooling system for maintaining a semiconductor chip at approximately a constant temperature by monitoring the present temperature of the chip and varying the air flow over a heat sink in thermal contact with the chip in response to the temperature. In addition, the temperature difference between the semiconductor chip module and a printed circuit board is also monitored to maintain that difference at a preset value. The air flow is varied by a variable speed fan or a variable direction baffle.

Electronic package having active means to maintain its operating

A method of making a multilayered circuit board wherein at least two layered subassemblies, each comprising a dielectric layer and at least one conductive layer therein, are bonded together. Each subassembly includes a through-hole extending therethrough which is aligned with a respective through-hole of the other prior to bonding. The subassemblies are compressed at a predetermined pressure (e.g., 300 psi) and then heated to a first temperature (e.g., 300.degree. C.) for an established time period, resulting in formation of a bond between the two through-holes. The resulting alloy formed from this bond possesses a melting point significantly greater than that of the subassembly dielectric (e.g., PTFE). Following this time period, the compressed subassemblies are heated to an even greater temperature (e.g., 380.degree. C.), again for an established time period, to assure dielectric flow. The subassembly is then cooled and the pressure removed. The method possesses two significant features: (1) effective engagement between respective pairs of through-holes in the compressed subassemblies; and (2) prevention of dielectric incursion within the bond formed between the respective pairs of through-holes, which incursion could adversely affect the electrical connection therebetween.

Multilayered circuit board

Method of making multilayered circuit board

Growing community of inventors

Endwell, NY, United States of America

Tien Y Wu