System and method for an improved fine pitch joint

A method of forming an interconnect, comprising:

• applying a flux on a mounting surface of a mounting pad disposed on a first surface of a first substrate;
• applying a metal ball on the flux;
• heating the metal ball in a convection environment;
• forming a molding compound around the interconnect, the molding compound exposing an upper portion of the metal ball, wherein before the forming the molding compound, the metal ball has a first height and a first width, and wherein after the forming the molding compound, the metal ball has the first height and the first width;
• and
• reflowing the metal ball, wherein after the reflowing, the metal ball has the first height and the first width, the first height being about equal to the first width, wherein the flux, the convection heating environment, and the molding compound are utilized to control the first height and the first width of the metal ball.

A method comprising:

• forming a mounting pad over a first substrate;
• forming a conductive interconnect on a mounting surface of the mounting pad, a sidewall of the conductive interconnect contacting the mounting pad at a sidewall angle, the sidewall angle being less than about 20 degrees from a plane perpendicular to the mounting surface of the mounting pad, the forming the conductive interconnect further comprises:
• applying a flux on the mounting surface of the mounting pad;
• applying a metal ball to the flux;
• and
• heating the metal ball in a convection environment to form the conductive interconnect;
• forming a molding compound around the conductive interconnect, the molding compound covering at least a lower portion of the conductive interconnect, at least a portion of the conductive interconnect being exposed through the molding compound, wherein the flux, the convection heating environment, and the molding compound are utilized to control the sidewall angle of the conductive interconnect;
• and
• bonding a second substrate to the conductive interconnect, the second substrate being separated from a top surface of the molding compound by a first distance measured in a direction perpendicular to a major surface of the second substrate.