Managing thermal warpage of a laminate
AssigneeInternational Business Machines Corporation
InventorsCharles L. Arvin, Marcus E. Interrante, Thomas E. Lombardi, Hilton T. Toy, Krishna R. Tunga, Thomas Weiss
Life of this patent
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Abstract
A method of managing thermal warpage of a laminate which includes: assembling a stiffener and an adhesive on the laminate, the stiffener being a material that has a higher modulus of elasticity than the laminate; applying a force to deform the laminate a predetermined amount; heating the laminate, stiffener and adhesive to a predetermined temperature at which the adhesive cures to bond the stiffener to the laminate; cooling the laminate, stiffener and adhesive to a temperature below the predetermined temperature, the laminate maintaining its deformed shape.
Claims16
A method of managing thermal warpage of a laminate comprising:
- assembling a stiffener and an adhesive on the laminate, the stiffener being a material that has a higher modulus of elasticity than the laminate;
- applying a force to deform the laminate a predetermined amount so as to drive the thermal warpage of the laminate at a solder reflow temperature of a semiconductor chip joined to the laminate during a subsequent semiconductor chip joining process to zero, plus or minus 20 μm, the predetermined amount related to the thermal warpage of the laminate due to the stiffener and the thermal warpage of the laminate due to the adhesive;
- heating the laminate, stiffener and adhesive to a predetermined temperature at which the adhesive cures to bond the stiffener to the laminate;
- and
- cooling the laminate, stiffener and adhesive to a temperature below the predetermined temperature, the laminate maintaining its deformed shape.
A method of managing thermal warpage of a laminate comprising:
- assembling a stiffener and an adhesive on the laminate, the stiffener being a material that has a higher modulus of elasticity than the laminate,
- wherein the laminate is an organic laminate having a glass transition temperature (Tg) and wherein the stiffener is a metallic stiffener that has a coefficient of thermal expansion (CTE) within ±1 ppm/° K of the laminate at a temperature range above the glass transition temperature of the laminate;
- applying a force to deform the laminate a predetermined amount, the predetermined amount related to the thermal warpage of the laminate due to the stiffener and the thermal warpage of the laminate due to the adhesive;
- heating the laminate, stiffener and adhesive to a predetermined temperature at which the adhesive cures to bond the stiffener to the laminate;
- and
- cooling the laminate, stiffener and adhesive to a temperature below the predetermined temperature, the laminate maintaining its deformed shape.
A method of managing thermal warpage of an organic laminate, the method comprising:
- assembling a metallic stiffener and an adhesive on the organic laminate to form a laminate assembly, the metallic stiffener being a material that has a higher modulus of elasticity than the laminate, the metallic stiffener chosen to have a coefficient of thermal expansion (CTE) within ±1 ppm/° k of the laminate at a temperature range above a glass transition temperature (Tg) of the organic laminate;
- applying a force perpendicular to a plane of the laminate to deform by a predetermined amount the laminate in a direction perpendicular to the plane of the laminate;
- heating the laminate assembly to a predetermined temperature above the Tg of the laminate at which predetermined temperature the adhesive cures to bond the stiffener to the laminate;
- and
- cooling the laminate assembly to a temperature less than the Tg, the laminate maintaining its deformed shape after cooling to the temperature less than the Tg.
Dependencies are inferred from the claim text.