Method of manufacturing a compact optical semiconductor module capable of being readily assembled with a high precision
AssigneeNEC Corporation
InventorYasuhisa Tanisawa
Life of this patent
Estimating the term…
Abstract
In an optical semiconductor module having an optical semiconductor chip mounted on a substrate through a plurality of solder bumps each of which has a predetermined height and which is formed by molten solder, each of the bumps is surrounded by a side wall lower than the predetermined height of each bump. The optical semiconductor chip is precisely positioned on the substrate not only in a horizontal direction by self-alignment effect of the molten solder but also in a vertical direction due to shrinkage of the molten solder with a bottom surface of the optical semiconductor chip kept contact with upper surface of the side walls, upon cooling the molten solder.
Claims7
A method of manufacturing an optical semiconductor module which comprises a substrate having a principal surface and an optical semiconductor chip mounted on said principal surface, said method comprising the steps of:
- depositing a plurality of first electrodes on a chip surface of said optical semiconductor chip;
- providing side walls which are offset relative to said substrate around portions of said principal surface, each of said side walls having a wall height;
- depositing a plurality of second electrodes at said portions;
- forming, on said second electrodes, a plurality of solder bumps each of which has a first height higher than said wall height;
- shrinking each of said solder bumps to have a second height substantially equal to said wall height at which said chip surface of said optical semiconductor chip is brought to rest on said principal surface of said substrate.
A method of manufacturing an optical semiconductor module which comprises a semiconductor structure having a principal surface, and an optical semiconductor chip mounted on said principal surface, said method comprising the steps of:
- (a) forming a plurality of first electrodes on a chip surface of said optical semiconductor chip;
- (b) forming a plurality of recessed portions within said principal surface, said recessed portions having side walls of a first height;
- (c) forming a plurality of second electrodes on a bottom surface of said recessed portions;
- (d) forming a plurality of solder bumps on said plurality of second electrodes, each of said solder bumps having a second height higher than said first height;
- (e) electrically connecting said solder bumps to said first electrodes;
- and
- (f) shrinking each of said solder bumps to a third height, substantially equal to said first height.
Dependencies are inferred from the claim text.