Inputs
- Base copper weight
- Plated copper thickness
FPC / PCB Engineering Calculator
Copper Thickness Converter: 1 oz to um
Convert PCB copper thickness between oz, um, mil and mm, including 1 oz to um, base copper and plated copper thickness.
How to use the Copper Thickness Converter (1 oz to um)
Copper thickness conversion is a foundation step for stack-up review, plating planning and trace current estimates. Use this page to convert copper weight into microns, mils and millimeters, including common 1 oz to um checks.
Copper weight to thickness
Formula: Copper thickness (um) = Copper weight (oz) x 34.79 + plated copper (um)
- Copper weight: base copper foil weight in oz/ft2.
- Plated copper: additional copper deposited by plating.
- Total copper: base copper plus plated copper.
Formula Basis
- Formula basis: standard copper mass-per-area conversion using copper density; 1 oz/ft2 is commonly treated as about 34.79 um, so the 1 oz to um conversion is shown explicitly.
- Engineering note: measured finished copper should be confirmed with the PCB / FPC manufacturer when plating or current capacity is critical.
Example
0.5 oz base copper with 18 um plated copper gives about 35.4 um total copper.
Outputs
- Total copper in um
- Total copper in mil
- Total copper in mm
Engineering Notes
- FPC flex areas often use thinner RA copper for bend performance.
- Finished copper should include plating where current capacity or etching result is reviewed.
- Factory reports may use nominal copper weight, measured copper thickness, or finished copper thickness. Keep the term consistent.
Validation Checks
- Stack-up total thickness
- Trace current capacity
- Etching compensation
- Plating specification
Related Manufacturing Process
- Material Selection - PI / PET / FR-4 thickness, RA or ED copper, adhesive type, coverlay thickness
- Stack-up Design - Total thickness, dielectric spacing, symmetry, controlled impedance
- Copper Plating - Current density, copper thickness, throwing power, plating area loading
Related Calculators
- Stack-up Thickness & Feature Drawing Tool - Build stack-up thickness and draw coverlay openings, air gaps, through holes, buried vias and blind vias for engineering review.
- Stiffener / ZIF Thickness Calculator - Check assembled FPC stiffener thickness against a connector or ZIF target thickness.
- Engineering Unit Converter - Convert common PCB and FPC engineering units, including 1 oz to um copper thickness.
FAQ
Is 1 oz copper exactly 35 um?
It is commonly rounded to 35 um. This calculator uses 34.79 um as the engineering conversion basis.
Should plated copper be added for FPC?
Yes, when the conductor receives copper plating and the finished copper thickness affects current, resistance, etching or hole reliability.