Easily Overlooked Details in PCB Layout

 

  1. Distance between through-hole components and SMD components As shown in the figure above, a sufficient distance should be maintained between through-hole resistors and SMD components, preferably 1-3mm. Currently, through-hole components are rarely used due to the complexity of processing.
  2. Heat dissipation considerations when pads are in a solid copper area If a pad is located in a solid copper area, the connection between the pad and the solid copper should follow the method on the right. Additionally, the number of connecting wires (1 or 4) should be determined based on the current. Using the method on the left may cause difficulties in soldering or removing components during maintenance, as heat will be dispersed through the solid copper, making it hard to reach the required temperature.
  3. Teardrops required when wires are narrower than through-hole pads If the wire width is narrower than the pad of a through-hole component, teardrops should be added as shown in the method on the right. Adding teardrops offers the following benefits:
  • Prevents signal reflection caused by a sudden reduction in wire width, ensuring a smooth transition between the trace and the component pad.
  • Solves the problem of potential breakage at the connection between the pad and the trace due to impact.
  • Makes the PCB look more visually consistent.
  1. Vias should not be placed on pads Note that through vias should not be placed directly on pads, as this may cause solder leakage and cold solder joints.
  2. Electrolytic capacitors must be kept away from heat sources First, ensure that the ambient temperature meets the requirements of electrolytic capacitors. Second, place capacitors as far as possible from heat-generating areas to prevent the liquid electrolyte inside the capacitors from drying out due to high temperatures

If you want know about PCB layout detail pls contact Sandy at hitechpcb.com




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