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Place electronics parts correctly on PCB

Let’s go through a few examples of how to place electronic parts correctly on the PCB board.

SMD electronic parts, especially if the lead pitch is above 1 mm, then placement of leads has to be symmetrical on copper planes:

If IC has a smaller lead pitch like 0.5 – 0.8mm, positioning by hand becomes harder. Sometimes it is recommended to use special glue to fix SMD parts before soldering.

DIP electronic parts must be soldered as close to the PCB board as possible to make them stand stable and avoid heat resistance.

Electronic parts with axial leads are placed vertically for better air ventilation. Thus, diode and Zener diodes have to be mounted with cathodes with a gap of 1-2 mm between the electronic part and the PCB board. If there is enough place – they can be mounted horizontally. This way, between the electronic part and PCB, has to be a gap of about 1 – 2 mm.

Single side pin electronic components like ceramic, electrolytic capacitors, crystals, semiconductor fuses have to be placed with a minimal gap (about 1 mm) between PCB.

H49U crystals have to be placed with a minimal gap between PCB. If there are no holes or tracks under the resonator, it is better to sell them without gaps. For crystals with high packages H49, it is better to bend them towards PCB with a ground plane. It is recommended to glue the side of the crystal to PCB.

LED’s with a diameter of 5mm; it is recommended to mount close to PCB without gaps. Miniature LED’s (diameter of 3mm) is mounted at the fixed-length left on leads.

Bigger electrolytic capacitors can be mounted close to PCB or bent:

Mechanical parts like buttons, jumpers, LCD usually have fixers or screw holes fixed to PCB. In other cases, parts have to be fixed tightly closer to PCB.

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