Thermal profilers are temperature instruments or recorders that provide temperature profiles for furnaces, kilns, or other continuous thermal processes. Some thermal profilers are enclosed in an insulated case and can travel along with components in an oven or furnace. Thermal profilers are frequently used in surface mount technology (SMT) reflow ovens to monitor the soldering temperatures used in making printed circuit boards (PCBs). They meet a variety of quality standards and are available from many different suppliers.
Thermal profilers are used to determine the optimum temperature in both the heating zone and cooling zone in an SMT reflow oven to ensure high-quality soldered joints in PCBs. Thermal profiling enables PCB manufacturers to monitor the quality of furnace and oven equipment and make necessary adjustments to any particular machines that may be outside of the ideal thermal profile. The thermal profile needed for one PCB assembly may be different for another, depending upon the configuration of different components. Thermal profilers work to establish standard profiles for specific PCB products, ensuring that optimum conditions are based on each configuration.
The introduction of lead-free solder alloys has complicated the heat treating process in PCB manufacturing. The temperature needed to melt the solder is close to the temperature that may damage some components. Thermal profilers allow manufacturers to balance reflow temperatures with safe operating temperatures. A thermal profiler is able to measure the actual temperature of the circuit, enabling manufacturers to determine a specific operating temperature range that produces quality soldering joints while minimizing damage to the circuit. Since thermal profilers are self-contained, battery-powered temperature recorders (data loggers,) may travel behind or be mounted directly on the PCB as it passes through the oven. The temperature instrument is connected to the circuit through a series of thermocouple leads that can be connected to multiple points along the circuit.