The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 25, 2000
Filed:
Jan. 13, 1997
Lee Melbourne Cook, Steelville, PA (US);
David B James, Newark, DE (US);
Charles William Jenkins, Newark, DE (US);
Heinz F Reinhardt, Chadds Ford, PA (US);
John V Roberts, Newark, DE (US);
Raj Raghav Pillai, Newark, DE (US);
Rodel, Inc., Newark, DE (US);
Abstract
Polymer-based pads useful for polishing objects, particularly integrated circuits, having interconnected porosity which is uniform in all directions, and where the solid portion of said pad consists of a uniform continuously interconnected polymer material of greater than 50% of the gross volume of the article, are produced directly to final shape and dimension by pressure sintering powder compacts of thermoplastic polymer at a temperature above the glass transition temperature but not exceeding the melting point of the polymer and at a pressure in excess of 100 psi in a mold having the desired final pad dimensions. In a preferred version, a mixture of two polymer powders is used, where one polymer has a lower melting point than the other. When pressure sintered at a temperature not to exceed the melting point of the lower melting powder, the increased stiffness afforded by incorporation of the higher melting polymer component gives improved mechanical strength to the sintered product. Conditions for producing the pads of this invention are such that the polymer powder particles from which the pads are produced essentially retain their original shape and are point bonded to form the pad.