Polyamide material is heated until liquid

The low viscosity polyamide material flows gently into the mold-set cavity and around the electronics to be encapsulated. It also starts cooling down as soon as it touches the mold-set cavity and the electronics. A mold-set cavity is typically filled in a few seconds but a typical full molding cycle is 20 to 45 seconds. As the Polyamide material starts to cool down it also starts to shrink. Continuous injection pressure is therefore applied to the cavity, even after its initial fill. This is done in order to compensate for the shrinkage that naturally occurs when the Polyamide material goes from liquid to solid (i.e. hot to cold). The Polyamide temperature is not too hot for the electronics and does not re-melt or re-flow the solder. This is simply because the relative cold mold-set will absorb the brunt of the heat, thereby reducing the temperature that a circuit board may see. Millions of circuit boards are successfully over-molded without causing any harm in the process. A low injection pressure does not stress a fragile solder joint.