Method of manufacturing semiconductor device
View Patent ↗When a bump electrode is formed on an opening formed in a semiconductor substrate, the invention prevents a void that is caused by gas trapped in the opening. A method of manufacturing a semiconductor device of the invention includes forming a first wiring on a main surface of a semiconductor substrate, forming an opening in the semiconductor substrate from the back surface to the main surface so as to expose the back surface of the first wiring, forming a second wiring connected to the back surface of the first wiring and extending from inside the opening onto the back surface of the semiconductor substrate, forming a solder layer connected to part of the second wiring on the bottom of the opening and extending from inside the opening onto the back surface of the semiconductor substrate, and forming a bump electrode on the opening by reflowing the solder layer.
1. A method of manufacturing a semiconductor device, comprising:
providing a semiconductor substrate comprising a first insulation film formed on a main surface of the semiconductor substrate;
forming a first wiring on the first insulation film;
forming an opening in the semiconductor substrate from a back surface of the semiconductor substrate so as to expose the first insulation film, the opening having a first end at the main surface and a second end at the back surface;
forming a second insulation film in the opening and on the back surface;
forming a second wiring on the second insulation film so that the second wiring is connected to the first wiring at the first end and extends from inside the opening and beyond the second end to cover a portion of the back surface;
forming a continuous solder layer on the back surface so as to be in contact with the second wiring extending beyond the second end and so as to enter the opening to cover only a portion of the second wiring on a sidewall and also a portion of the second wiring on a bottom of the opening; and
reflowing the solder layer so that a portion of the solder layer flows into the opening,
whereby the solder layer is formed on the back surface so that a portion of the solder layer is in contact with the second wiring at the first end of the opening prior to the reflowing.
2. The method of claim 1 , wherein the solder layer is formed by a screen printing method.
3. The method of claim 1 , wherein the solder layer is formed by a dispensing method.
4. The method of claim 1 , wherein the second end of the opening is truncated.
5. The method of claim 1 , wherein the opening is formed so as to have a cylindrical shape.