Using FireBoard 2 Pro for Reflow Profiling
In October 2019, FireBoard began producing our own circuit boards with the addition of a surface mount assembly line. The final stage in our PCB assembly line is a BTU Pyramax 8-zone reflow oven. This is where the melting and then cooling of solder creates electrical connections between surface-mounted components and the board. Unlike a conventional food oven, the Pyramax reflow oven uses 8 stages of heating and a final cooling stage to ensure proper bonding of the components to the PCB and to form secure and reliable solder joints.
Building a Reflow Profile
To ensure the oven is properly set for the board being assembled, Matthew Zuiss, one of FireBoard’s techs, can test the oven’s performance. This process ensures proper soldering of electronic components onto the PCB by comparing the reading to the specific temperature profile provided by the component manufacturer (this is known as the reflow profile). All to ensure the melting and solidification of solder at different stages, ensuring reliable and consistent connections.
Zuiss explains, “We are looking at how quickly temp rises—and how long it stays at that temp. According to the chip manufacturer, it should be at peak temp for a specific amount of time.” If needed, adjustments are made to the oven’s zone temperatures and conveyor speeds.
A Purpose-Built Thermocouple Probe
To perform his measurements, Matthew uses a stock FireBoard 2 Pro and a special probe made from a length of Type K thermocouple wire soldered to a special circuit board. The oven’s conveyors carry the special board through the oven, giving real-time measurements.
How Does a Thermocouple Work?
The function of a thermocouple probe is a fascinating reaction between of two different metals joined together. When exposed to temperature changes, these metals produce a voltage due to the Seebeck Effect. The temperature is then measured by interpreting the voltage generated.