Lets go through few examples how to place electronic parts correctly on PCB board.

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

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

DIP electronic parts has to be soldered as close to PCB board as possible to make them stand stabile and to avoid heat resistance.

Electronic parts with axial leads are placed vertically for better air ventilation. Because of this diodes and Zener diodes has to mounted with cathodes up with gap of 1-2 mm between electronic part and PCB board. If there is enough place – they can be mounted horizontally. This way between 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 minimal gap (about 1 mm) between PCB.

H49U crystals have to be placed with minimal gap between PCB. It under resonator there is no via holes or tracks, then it is better to solder them without gaps. Crystals with high packages H49 it is better to bend them towards PCB with Ground plane. It is recommended to glue side of crystal to PCB.

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

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

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

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This entry was posted on Friday, September 22nd, 2006 at 1:51 pm and is filed under Electronics, UV PCB Making. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.