Generally speaking, it is nothing more than cost. In terms of size or weight, smd resistor are about 1/10 less than plug-in resistor. Generally, after SMT is adopted, the volume of electronic products is reduced by 40% to 60%, and the weight is reduced. 60%~80%. High reliability, strong anti-vibration ability, low solder joint defect rate, good high-frequency characteristics, reduced electromagnetic and radio frequency interference, easy to realize automation, increase production efficiency, and reduce costs by 30% to 50%.
Save materials, energy, equipment, manpower and working hours. For example, the commonly used smd resistor 0805 package or 0603 package is much smaller than the in-line resistor we used before. A bag can be filled with dozens of in-line resistor, but it is enough to hold thousands or even tens of thousands of them if replaced with smd resistor. If the power can be met, surface mount devices are generally preferred.
SMD resistor do not need vias and use less tin. The most troublesome in-line resistor is disassembly. When disassembling on a PCB with two or more layers, even if there are only two pins, it is not easy to remove it, and it is easy to damage the circuit board, other multi-pin Not to mention the components. It is much easier to disassemble the SMD electronic components, not only the pins are easy to disassemble, but also the circuit board is not easy to damage. The main tool for disassembling in-line components is a solder sucker. The automatic solder sucker is expensive, not easy to maintain, easily damaged, or blocked by air holes.