In general, an electrically conductive pad is formed on a substrate to couple an electrically conductive pillar on a semiconductor die to the electrically conductive pad. In order to facilitate the coupling between the electrically conductive pad and the electrically conductive pillar, a solder is plated or coated onto the electrically conductive pad prior to the coupling.
In order to couple a semiconductor die to a substrate, the semiconductor die is first aligned with the substrate. Heat is applied to the substrate at high temperature to cause a solder to reflow. The substrate is subsequently cooled electrically and mechanically coupling the electrically conductive pillar on the semiconductor die to the electrically conductive pad on the substrate via the solder.
A passivation layer is coated on the substrate excluding the electrically conductive pad. Thus, the electrically conductive pads are exposed directly to the outside. Further, the electrically conductive pad is formed in a line shape having a predetermined length. Thus, during a reflow process for interconnecting the semiconductor die to the substrate, the solder previously formed by plating on the electrically conductive pad (hereinafter, to be called a “plating solder”) has an irregular shape. That is, the molten plating solder may exist only on a portion of the line-shaped electrically conductive pad, which is generally referred to as “solder flying.” In this case, a non-wetting phenomenon may occur in which the solder may not be formed on a portion of the electrically conductive pad that is substantially coupled to the electrically conductive pillar on the semiconductor die.
Accordingly, a conventional semiconductor device having the above-mentioned configuration may often suffer from failure of electrical and mechanical connection between the electrically conductive pillar and the electrically conductive pad, or faulty solder connection.
Therefore, a need existed to provide a system and method to overcome the above problem.