Process for forming cone shaped solder for chip interconnection

A process for forming non-spherical shapes in solder interconnects comprising the steps of:

• (a) providing a semiconductor wafer and a substrate for mounting said wafer;
• (b) applying a masking layer to said wafer or to said substrate;
• (c) patterning and developing a plurality of openings in said masking layer;
• (d) forming a plurality of solder interconnects by plating a layer of solder into said plurality of openings in said masking layer;
• and
• (e) molding said plurality of solder interconnects into a non-spherical shape,
• wherein the non-spherical shape of said plurality of solder interconnects facilitates joining of said wafer and said substrate in a non-planar environment.

A process for forming cone shaped solder on a semiconductor wafer or a substrate for use in controlled chip collapse connections comprising the steps of:

• (a) providing a first surface;
• (b) applying a bond pad for a connection to said surface;
• (c) applying a seed layer over said surface;
• (d) applying and patterning a masking layer over said seed layer to form an opening in said masking layer exposing said seed layer;
• (e) plating a metal solder into the opening of said masking layer;
• (f) stripping said masking layer;
• (g) removing said seed layer not covered by said solder;
• and
• (h) molding said solder to form a cone shape.

A method of joining semiconductor chips and substrates in a non-planar environment using non-spherically shaped solder comprising the steps of:

• (a) providing a semiconductor chip and a substrate for mounting said chip;
• (b) forming a plurality of non-spherical solder interconnects on a surface of said chip or substrate;
• (c) forming standoffs on a surface of said chip or said substrate;
• and
• (d) contacting said chip with said substrate,
• whereby the placement force is reduced and said standoffs limit the extent of collapse of said solder interconnects.

A method of joining semiconductor chips and substrates in a non-planar environment using non-spherically shaped solder comprising the steps of:

• (a) providing a semiconductor chip and a substrate for mounting said chip;
• (b) forming a plurality of non-spherical solder interconnects on a surface of said chip;
• (c) forming standoffs on a surface of said chip or substrate;
• and
• (d) contacting said chip with said substrate,
• whereby the placement force is reduced and said standoffs limit the extent of collapse of said solder interconnects.

A method of joining semiconductor chips and substrates in a non-planar environment using non-spherically shaped solder comprising the steps of:

• (a) providing a semiconductor chip and a substrate for mounting said chip;
• (b) forming a plurality of non-spherical solder interconnects on a surface of said substrate;
• (c) forming standoffs on a surface of said chip or said substrate;
• and
• (d) contacting said chip with said substrate,
• whereby the placement force is reduced and said standoffs limit the extent of collapse of said solder interconnects.