US 6,150,255 AGranted

Method of planarizing a curved substrate and resulting structure

AssigneeInternational Business Machines Corporation

InventorsFrancis Joseph Downes, Jr., Stephen Joseph Fuerniss, Gary Ray Hill, Anthony Paul Ingraham, Voya Rista Markovich, Jaynal Abedin Molla

Life of this patent

Estimating the term…

patentgrep

Loading patent…

Abstract

According to the present invention a technique for providing a planarized substrate with dendritic connections of solder balls, especially a multi-layer ceramic substrate is provided. In the case where the substrate has a raised central portion on the top surface on which are disposed top surface metallurgy pads, a layer of conformable photoimagable material is placed over the top surface. The photoimagable material is exposed and developed in a pattern corresponding to the pattern of the top surface metallurgy pads to form vias in the photoimagable material. Copper is plated in the vias in contact with the top surface metallurgy pads. The exposed surface of the photoimagable surface is then planarized, preferably by mechanical polishing to form a flat planar surface, with the ends of the vias exposed. Dendritic connector pads are then grown on the exposed ends of the vias to which solder ball connections of an I/C chip are releasably connected.

Claims13

Dependent claims

A method of manufacturing a substrate for the removable reception of an integrated circuit (I/C) chip thereon, comprising the steps of:

providing a dielectric substrate having a top surface with a plurality of top surface metallurgy (TSM) pads therein, and wherein said top surface has a curvilinear configuration over at least the portion thereof where the TSM pads are located,
applying to the top surface of said substrate over said TSM pads a compliant photoimagable material having an exposed surface thereon,
photoimaging and developing said photoimagable material to provide a plurality of vias corresponding to the TSM pads and extending from the exposed surface to said underlying TSM pads,
depositing electrically conducting material in said vias in contact with said TSM pads, and extending at least to the exposed surface of said photoimagable material,
planarizing said exposed surface and said conducting material in said vias to an essentially flat planar configuration of the exposed surface and the top surface of said conducting material in the region of said vias, and
providing releasable electrical connections on said conducting material in said vias projecting from said planarized exposed surface of said photoimagable material.

3 more elements

Dependencies are inferred from the claim text.

Facts

Application: 09/373,868Filed 13 Aug 1999 · division
Priority: 17 Apr 1996
Granted: 21 Nov 2000
Term ends: Not estimatedThe source records don’t support an estimate.

Classification21 codes

H10W 90/401
Package configurations: characterised by multiple insulating or insulated package substrates, interposers or RDLs
H10W 70/68
Characterised by their insulating layers or insulating parts: shapes or dispositions thereof
H10W 72/00
Interconnections or connectors in packages
H05K 1/0306
Use of materials for the substrate: inorganic insulating substrates, e.g. ceramic, glass