If you are buying PCB made in China, you may often come across some unit conversion issues? The Chinese PCB factories has their own style in making quotations, now let's review the commonly used unit conversion in PCB industry.
1. Metric System and English System
Metric System include the following unit:
dm
cm
mm
um
English System include the following unit:
ft
ln
mil
uin
PCB manufacturers often use cm/mm and inch/mil to measure line space/line width
2. Conversion
1dm=10cm
1ft=12in
1cm=10mm
1in=1000mil
1mm=1000um
1mil=1000uin
3. Metric and British mutual convesion
1in=2.54cm=25.4mm=25400um
1mil=25.5um
1mil=0.0254mm
1uin=0.0254um
1mm=39.37mil
1um=39.37uin
4. Copper foil thickness conversion
1oz=35um=1.35mil
2oz=70um=2.7mil
1/2oz=17.5um=0.7mil
1/3oz=11.7um=0.5mil
1/4oz=8.8um=0.35mil
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