Inputs
- Target X
- Target Y
- Shrinkage X
- Shrinkage Y
- Process bias X
- Process bias Y
FPC / PCB Engineering Calculator
Material Shrinkage Compensation Calculator
Calculate artwork or tooling compensation from X/Y shrinkage and process bias.
How to use the Material Shrinkage Compensation Calculator
FPC materials may shrink or expand through lamination, baking, etching and profiling. This calculator estimates X/Y artwork or tooling compensation from target size and directional shrinkage.
Directional shrinkage compensation
Formula: Tooling size = target size / (1 - shrinkage rate) + process bias
- Target size: desired final dimension after processing.
- Shrinkage rate: expected dimensional loss in each direction.
- Process bias: additional empirical correction from factory data.
Formula Basis
- Formula basis: dimensional compensation by inverse shrinkage ratio plus empirical process bias.
- Engineering note: real compensation should be built from FAI and factory measurement history by material and process route.
Example
A 100 mm target dimension with 0.12% shrinkage needs about 100.12 mm before process bias.
Outputs
- Compensated X size
- Compensated Y size
- X compensation
- Y compensation
Engineering Notes
- Use measured historical data whenever possible instead of generic shrinkage assumptions.
- X/Y shrinkage can be different because of material grain direction, panel layout and process flow.
- Different process stages may need separate compensation tables.
Validation Checks
- Final outline dimension
- Layer registration
- Tooling compensation
- FAI measurement feedback
Related Manufacturing Process
- Lamination - Lamination thickness, adhesive squeeze-out, registration, CTE mismatch
- Profiling / Routing / Punching - Routing tolerance, punch clearance, outline compensation, edge rail
Related Calculators
- Via Aspect Ratio Calculator - Check finished hole aspect ratio, drill allowance and annular ring.
- Etching Compensation Calculator - Estimate artwork width from finished trace width, copper thickness and etch factor.
- Copper Plating Time Calculator - Estimate copper plating current, time and amp-hour loading.
- PCB Panelization / Panel Utilization Calculator - Calculate PCB panelization count, rotation option and material utilization.
FAQ
Can shrinkage be negative?
Yes. Negative shrinkage represents expansion. The calculator will reduce the compensated size accordingly.
Where should the process bias come from?
The best source is factory measurement history by material, panel size, copper ratio and process route.