Method of forming solder on pad on fine pitch PCB and method of flip chip bonding semiconductor using the same

摘要

Disclosed are a method of forming a solder on pad on a fine pitch PCB and a method of flip chip bonding a semiconductor device using the same. The method of forming a solder on pad on a fine pitch PCB includes: applying a solder bump maker (SBM) paste with a predetermined thickness to an entire surface of a PCB including a metal pad and a solder mask; heating the SBM paste at a temperature higher than a melting point of solder contained in the SBM paste and then cooling the SBM paste to form a solder on pad; and washing a residual polymer resin and residual solder particles of the SBM paste by using a solvent.

主权项

1. A method of forming a solder on pad on a fine pitch PCB, the method comprising:
forming a metal pad and a solder mask on a PCB, wherein:
the metal pad has a lower surface facing the PCB and an opposite upper surface,the solder mask has a lower surface facing the PCB and an opposite upper surface, andthe upper surface of the solder mask is disposed at a level higher than a level at which the upper surface of the metal pad is disposed; applying a solder bump maker (SBM) paste with a predetermined thickness over an entire surface of the PCB including the metal pad and the solder mask, wherein the SBM paste applied over the PCB forms a first region covering the upper surface of the metal pad and a second region covering the entire upper surface of the solder mask, and the SBM paste of the first region has a bottom surface facing the metal pad and a top surface opposite to the bottom surface, the top surface being disposed at a level higher than a level at which the upper surface of the solder mask is disposed; while the SBM paste is above the solder mask, at a temperature higher than a melting point of solder contained in the SBM paste and then cooling the SBM paste to form a solder on pad; and washing a residual polymer resin and residual solder particles of the SBM paste by using a solvent.