Oven setup temperature is not exactly the same as PCB temperature. The PCB thickness and the components’ thermal capacitance will affect heat transfer.
It is also the key parameter in obtaining quality soldering. To obtain a given time and temperature profile, technicians modify the conveyor speed and zone temperatures. PCBs are treated at a regulated rate as they pass through the oven and each zone. PCB thermal capacitance impacts the thermal stability of the target board. Commercial conveyorised reflow ovens include numerous separately heated zones that may be individually temperature adjusted. Metals have less thermal resistance than non-metal materials, so the number of PCB layers and cooper thickness will affect heat transfer. 250 C is recommended as the maximum temperature for all solder joints on the board, except for components with temperature ratings lower than 250 C. It may be related to the oven setup temperature directly however, it is not the same as the value of set up point.Įvery material has thermal resistance. Reflow oven chamber temperature is the hot air temperature. For the reflow oven, a peak temperature value of 422 o F (217 o C) and a TAL of 70 sec was specified. The greater the difference between PCB temperature and oven chamber temperature, the faster the PCB board will get heat. In most of situations, the initial PCB temperature is the same as room temperature. There are many factors that affect the board’s ability to warm up accurately. The data of hot air temperature around this particular heat element will be fed back to controller, which decide to turn on or off the heat energy. This is a closed loop control process using a modern PID control concept. With the help of a DIY thermocouple measurement system, you can use a cheap toaster oven to accurately reproduce a reflow-soldering temperature profile.
Reflow oven zone temperature is a set point where the heat element will be heated to reach this temperature set point. Before starting to “cook” the target board, the reflow oven zone temperature needs to be set up. The process of hot air reflow soldering is essentially a heat transfer process. Reflow oven zone temperature set up and thermal profile
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