You can use the reflow profiles in the code if you use the same type or set up a new profile based on the solder paste that you are using. One is 183 degree SN-PB and the other one is 138 degree lead free type. Currently I have two types of solder paste. It uses PID based temperature controlling which I explained in a previous video. So I reduced the trace resistance by shorting the wire and then I was able to reach 230 degree Celsius. But Still I couldn’t reach the desired temperature. Later I fixed it by using alligator clips instead of soldering the wire directly. Because the entire PCB was heating up so the solder joint melted. So at 24 volts it draws about 7 amps of current and the temperature rises to 178 degree Celsius.Īt that time the connection was interrupted because one of the wires got disconnected from the PCB. Initial Testing:Īfter getting the PCB I first measured the trace resistance and it’s 4 ohms which is slightly bigger than the previously calculated value. After designing the PCB I head over to PCBway for manufacturing the PCB. There are two mosfets to control the heatbed and a small cooling fan. Along with MAX6675 ic with k type thermocouple. I will use this TTGO T-Display module since it has a builtin TFT display. An online calculator shows that the trace resistance will be 3 ohms.Īnd at 24v it will draw about 200w of power. Although aluminium PCBs are bit more expensive, they are well suited for this job. So regular FR4 PCB is not a suitable option, But aluminium PCBs are made to withstand high temperatures and they spread the heat evenly throughout the entire surface. and since my last experiment 200 to 220 degree celsius should be sufficient for the solder paste that I use. Key things to note here is that different solder paste has different melting point. ![]() So if we make a PCB that has a very lengthy trace and apply voltage to it’s end terminals it should generate enough heat to reflow a PCB. The idea is simple, when you apply power to both ends of a conductor, it generates heat. The only issue is it uses mains AC voltage which I don't feel super comfortable to work with so I tried low voltage DC approach. Last time I made a reflow soldering hotplate from a regular clothing iron.
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