1. Field of the Invention
The present invention relates to a process of reducing friction, which is encountered in molds utilized in injection molded solder processing.
2. Background Art
In the fabrication of mold plates, which are utilized for purposes of injection molded solder processes, particularly those employed to produce semiconductor chip connection processes, for instance, such as for the controlled collapse chip connect new process (C4NP), the normally glass material mold plates are generally produced utilizing an etching process which causes the surface of the mold plates to be provided with mold pits or cavities. These etched mold pits in the mold plate surfaces are frequently encountered in possessing sharp edges, whereby the sharp edges have a tendency to abrade the mold fill head o-rings of the mold apparatus. This may cause debris from the o-rings to be located on or embedded in the mold plate, which is equipped with pits or cavities to be filled with solder in order to produce the solder connections. Consequently, this presence of the sharp pit edges may result in defects in the components and operation of the molding apparatus, and in a reduced service life for the o-rings due to excessive wear during the employment thereof.
Moreover, the abrasive phenomenon which is encountered through the presence of the sharp edges of the etched pits in the surface of the mold plates, may also lead to an increase in friction forces opposing the motion of the mold plates during operation of the molding apparatus, potentially producing a reduction in operating margins or efficiency caused by a twisting of the fill head while dispensing the solder into the cavities which are to be filled therewith. Moreover, the resultant increase in friction may also generate debris deposited on the mold plate surface, which emanates from the fill head seal of the apparatus, thereby rendering the mold filling process subject to considerable difficulties.
Generally, as indicated, the mold plates may be constituted of a material such as glass, the property of which may be considered as constituting a “solid liquid” in the technology, and which, at elevated temperatures, acts in many instances like any other liquid, with forces due to surface tension, viscosity and interaction with neighboring materials comprising a determining in its behavior and characteristic.
In this instance, surface tension forces may possess a tendency to soften any sharp edges in the pits, which have been formed in the surface of the glass mold plates, and whereby an increase in the temperature to levels at which these forces can overcome the viscosity over a period of time at elevated temperatures may tend to smooth or round off the sharp edges of the mold pits.