1: Set the multimeter to the resistance measurement position, connect the two test leads to the metal of the soldering iron tip and connect the other test lead to the ground terminal of the power plug, and measure the resistance value. During the measurement, you need to stop for three seconds and keep stable equal to or less than 10Ω. If the measured value is greater than 10Ω, it means that the grounding is good; if the measured value is greater than 10Ω, it means that there is no grounding or the grounding is bad.
2: The soldering iron tip should not come into contact with plastics, lubricants, rubber and other compounds. If you come into contact with plastics, lubricants, and rubber during use, you need to clean it up with sponge and water in time, and then clean the soldering iron tip with tin.
The difference between manual welding of aluminum substrate PCB and FR4 PCB welding
1. Because the aluminum substrate has good heat dissipation, the aluminum parameter is thermal conductivity/237W/MK than hot melt/KJ/kg.k density/2.7/CM3. When soldering the plug-in components, choose an electric soldering iron with a power above 500W. When soldering the component pins to accommodate the tin, it can be completely accommodated, and it is not easy to cause worry about soldering, false soldering, etc. , The tin point on the pin is also satisfactory.
2. FR4 PCB has poor heat dissipation and good insulation, but it cannot withstand high temperatures. If the temperature is too high, it is easy to damage the circuit or the pads during operation. The physical properties of FR4 PCB will change at a certain temperature. The heat resistance of FR4 is represented by Tg, and the rated Tg of FR4 PCB is 130°C.
3. When selecting the soldering iron, it should be about 300W in the seat. The temperature of the soldering pin should be about 350~450 degrees. The temperature is too easy to burn the copper skin of the PCB or the pad is easy to fall off.
4. At the same time, please pay attention to the selection of tin wire. There are lead-tin wire and lead-free tin wire. The capacitance of lead-free tin wire is about 257 degrees, and the capacitance of lead-tin wire is about 178 degrees. At the same time, there are two types of tin wires. Cannot mix applications.