The laminated LTCC stack will be fired in a computer controlled furnace. The firing will follow a specific profile, which shows a slow rising of the temperature to burnout the organic. Then the temperature is increased up to 870°C, where the sintering takes place. Afterwards, the oven is cooled down. In a free sintering process the LTCC is shrinking up to 13% in X- and Y-direction and up to 15% in Z-direction (thickness). With the constrained or "zero" shrinking method the volume reduction is only 0.2% in X- and Y-, but 45% in Z-direction. IMST utilises unconstrained sintering only.
Process furnace peo 602 and 603 from atv.
Typical sintering profile for DuPont 951.