This function forces the furnace to reach the highest temperature set in the curve and to hold it for the defined time.
To avoid any strong overheating, the holding period starts with a tolerance of -8°C in reference to the highest temperature point. If the external sensor is in use, the phenomena will always be controlled by this. If the external sensor is not in use it will be controlled by furnace sensor. This function may extend (set a too steep curve) or shorten the process (too slow and/or too long at a high temperature).
eC-reflow-pilot hold time graph
The curve shows a process of a double sided PCB. The maximum temperature climb (ext. sensor) is between approx. 70°C-80°C per minute.
This is possible because of the support from the preheater set as „follow temp 0° C“.
This setting allows the preheater to unfold its full power.
In the curve we see that after 1,5 minutes the furnace temperature (160°C) rises over the preset temperature (150°C). As a consequence the temperature controller regulates to a slower curve as the external sensor is running behind due to thermal Inertia of the PCB. This gives a very smooth curve for the external sensor. During the entire processl the PCB is about 2.5 minutes above 225° C which causes all components to be soldered.
