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US 6,617,674 B2Granted
Semiconductor package and method of preparing same
AssigneeDow Corning Corporation
InventorsGregory Scott Becker, Geoffrey Bruce Gardner, Brian Robert Harkness, Louise Ann Malenfant, Satyendra Kumar Sarmah
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Abstract
A semiconductor package comprising a wafer having an active surface comprising at least one integrated circuit, wherein each integrated circuit has a plurality of bond pads; and a cured silicone layer covering the surface of the wafer, provided at least a portion of each bond pad is not covered with the silicone layer and wherein the silicone layer is prepare by the method of the invention.
Claims30
A semiconductor package comprising:
- a semiconductor wafer having an active surface comprising a plurality of bond pads;
- and
- a cured silicone layer covering the active surface of the wafer except the bond pads, wherein the silicone layer is prepared by a method comprising the steps of:
- (i) applying a silicone composition to the active surface of the semiconductor wafer to form a film, wherein the active surface comprises a plurality of bond pads, and the silicone composition comprises:
- (A) an organopolysiloxane containing an average of at least two silicon-bonded alkenyl groups per molecule,
- (B) an organosilicon compound containing an average of at least two silicon-bonded hydrogen atoms per molecule in a concentration sufficient to cure the composition, and
- (C) a catalytic amount of a photoactivated hydrosilylation catalyst;
- (ii) exposing a portion of the film to radiation having a wavelength of from 150 to 800 nm to produce a partially exposed film having non-exposed regions covering at least a portion of each bond pad and exposed regions covering the remainder of the active surface;
- (iii) heating the partially exposed film for an amount of time such that the exposed regions are substantially insoluble in a developing solvent and the non-exposed regions are soluble in the developing solvent;
- (iv) removing the non-exposed regions of the heated film with the developing solvent to form a patterned film;
- and
- (v) heating the patterned film for an amount of time sufficient to form the cured silicone layer.
9 more elements
A method of preparing a semiconductor package, the method comprising the steps of:
- (i) applying a silicone composition to an active surface of a semiconductor wafer to form a film, wherein the active surface comprises a plurality of bond pads, and the silicone composition comprises:
- (A) an organopolysiloxane containing an average of at least two silicon-bonded alkenyl groups per molecule,
- (B) an organosilicon compound containing an average of at least two silicon-bonded hydrogen atoms per molecule in a concentration sufficient to cure the composition, and
- (C) a catalytic amount of a photoactivated hydrosilylation catalyst;
- (ii) exposing a portion of the film to radiation having a wavelength of from 150 to 800 nm to produce a partially exposed film having non-exposed regions covering at least a portion of each bond pad and exposed regions covering the remainder of the active surface;
- (iii) heating the partially exposed film for an amount of time such that the exposed regions are substantially insoluble in a developing solvent and the non-exposed regions are soluble in the developing solvent;
- (iv) removing the non-exposed regions of the heated film with the developing solvent to form a patterned film;
- and
- (v) heating the patterned film for an amount of time sufficient to form a cured silicone layer.
6 more elements
A method of producing a patterned film, the method comprising the steps of:
- (i) applying a silicone composition to a surface of a substrate to form a film, wherein the silicone composition comprises:
- (A) an organopolysiloxane containing an average of at least two silicon-bonded alkenyl groups per molecule,
- (B) an organosilicon compound containing an average of at least two silicon-bonded hydrogen atoms per molecule in a concentration sufficient to cure the composition, and
- (C) a catalytic amount of a photoactivated hydrosilylation catalyst;
- (ii) exposing a portion of the film to radiation having a wavelength of from 150 to 800 nm to produce a partially exposed film having non-exposed regions covering a portion of the surface and exposed regions covering the remainder of the surface;
- (iii) heating the partially exposed film for an amount of time such that the exposed regions are substantially insoluble in a developing solvent and the non-exposed regions are soluble in the developing solvent;
- (iv) removing the non-exposed regions of the heated film with the developing solvent to form a patterned film;
- and
- (v) heating the patterned film for an amount of time sufficient to form a cured silicone layer.
6 more elements
A semiconductor package comprising:
- a semiconductor wafer having an active surface comprising a plurality of bond pads;
- a cured silicone layer covering the active surface of the wafer except the bond pads;
- a metal trace having a proximal end attached to each bond pad and a distal end lying on the surface of the silicone layer;
- and
- a solder mask covering the bond pads, the cured silicone layer, and the metal trace;
- wherein at least a portion of the distal end of the trace is free of the solder mask;
- and wherein the solder mask is prepared by a method comprising
- (i) applying a silicone composition onto a surface including the bond pads, the cured silicone layer, and the metal traces, to form a mask film;
- wherein the silicone composition comprises
- (A) an organopolysiloxane containing an average of at least two silicon-bonded alkenyl groups per molecule,
- (B) an organosilicon compound containing an average of at least two silicon-bonded hydrogen atoms per molecule in a concentration sufficient to cure the composition, and
- (C) a catalytic amount of a photoactivated hydrosilylation catalyst;
- (ii) exposing a portion of the mask film to radiation having a wavelength of from 150 to 800 nm to produce a partially exposed film having non-exposed regions covering the distal ends of the metal traces and exposed regions covering the remainder of the surface;
- (iii) heating the partially exposed mask film for an amount of time such that the exposed regions are substantially insoluble in the developing solvent and the non-exposed regions are soluble in the developing solvent;
- (iv) removing the non-exposed regions of the heated mask film with the developing solvent to form a patterned mask film;
- and
- (v) heating the patterned mask film for an amount of time sufficient to form the solder mask.
14 more elements
Dependencies are inferred from the claim text.