Bumpless flip chip assembly with solder via

A method of making a flip chip assembly, comprising the following steps in the sequence set forth:

• providing a substrate with first and second surfaces that are opposite one another and a via hole that extends between the first and second surfaces;
• depositing metallization on walls of the via hole;
• depositing solder on the metallization such that the solder is disposed in the via hole without filling the via hole;
• attaching the substrate to a semiconductor chip that includes a terminal pad, wherein the first surface is opposite the chip, the via hole exposes the pad and the solder contacts the pad;
• and
• applying heat to reflow the solder to form a solder joint that contacts and electrically connects the metallization and the pad and prevents the via hole from exposing the pad.

A method of making a flip chip assembly, comprising the following steps in the sequence set forth:

• providing a semiconductor chip that includes a terminal pad;
• depositing solder on the pad;
• attaching a substrate to the chip, wherein the substrate includes first and second surfaces that are opposite one another and a via hole that extends between the first and second surfaces, the via hole includes metallization on its walls, the via hole is aligned with the pad and exposes the solder, the solder contacts the metallization without filling the via hole, the first surface is opposite the chip, and the substrate is at a fixed position relative to the chip;
• and
• applying heat to reflow the solder such that the solder wets and flows on the metallization in the via hole and forms a solder joint that contacts and electrically connects the metallization and the pad while the substrate remains at the fixed position relative to the chip.

A method of making a flip chip assembly, comprising the following steps in the sequence set forth:

• providing a substrate with first and second surfaces that are opposite one another and a via hole that extends between the first and second surfaces;
• electrolessly plating metallization on walls of the via hole;
• electroplating solder on the metallization such that the solder is disposed in the via hole without filling the via hole;
• attaching the substrate to a semiconductor chip using an adhesive therebetween, wherein the first surface is opposite the chip, the chip includes a bumpless terminal pad, the via hole exposes the pad and the solder contacts the pad;
• and
• applying heat to reflow the solder such that the solder wets and flows on the pad and forms a solder joint that contacts and electrically connects the metallization and the pad and prevents the via hole from exposing the pad.

A method of making a flip chip assembly, comprising the following steps in the sequence set forth:

• providing a substrate with first and second surfaces that are opposite one another, wherein the substrate includes a via hole and a conductive trace, the via hole extends between the first and second surfaces, and the conductive trace includes metallization on walls of the via hole and a bond site outside the via hole;
• depositing solder on the metallization and the bond site, wherein the solder on the metallization is in the via hole, the solder on the bond site is proximate to the first surface and outside the via hole, and the solder on the metallization does not contact the solder on the bond site;
• attaching the substrate to a semiconductor chip, wherein the first surface is opposite the chip, the chip includes a terminal pad, the solder on the metallization contacts the pad, and the solder on the bond site does not contact the chip;
• and
• applying heat to reflow the solder such that the solder on the metallization forms a solder joint that contacts and electrically connects the metallization and the pad, the solder on the bond site forms a solder contact that does not contact the solder joint and does not contact the chip, and the conductive trace electrically connects the solder joint and the solder contact.