Issues Caused by Voids
- Reduced adhesion of device to substrate
- Reduced thermal performance
- Electrical failures from “solder creep”
- Lower reliability & shorter lifetime+
Pressure Curing Removes Voids
As pressure is increased, more gas molecules are able to dissolve (Henry’s Law)
- Henry’s Law – The amount of dissolved gas in a liquid is proportional to its partial pressure above the liquid.
- Increasing pressure during the curing process removes voids.
Pressure Curing Oven Process
- A Pressure Cure Oven (PCO), or Autoclave, is used to minimize voiding and increase adhesion strength for a variety of bonding and curing application.
- A PCO pressurizes a rigid chamber with air or Nitrogen and maintains a pressure profile during the curing cycle as defined by the recipe.
Convection heaters and heat exchangers maintain a recipe-defined thermal profile during the entire curing cycle.
A typical PCO temperature and Pressure profile.
Typical PCO Applications
- Die Attach Curing
- Underfill Curing
- Ag Sintering Cure
- MEMS Sealing
- Taping / Lamination
- PCB Via Fill
- Encapsulation Curing
- Composite Forming