FPC / PCB Engineering Calculator

FPC Stackup Drawing Tool: Thickness, Air Gap & Vias

Draw and calculate FPC stack-up thickness with coverlay openings, air gaps, through holes, buried vias, blind vias and copyable PNG output.

How to use the Stack-up Thickness & Feature Drawing Tool

Stack-up thickness and feature drawing are used for quotation, material selection, bend radius review, connector fit and reliability planning. This tool builds a layer-by-layer estimate with draggable assembly features for coverlay openings, air gaps, through holes, buried vias and flippable blind vias, then copies a clean stack-up diagram for PPT or engineering reports.

Zone layer sum

Formula: Zone thickness = included material thickness + air-gap thickness

  • Layer thickness: nominal material thickness in mm.
  • Included layer: material counted in the current local zone.
  • Air gap: spacing retained in the geometry, but not counted as material.
  • Removed / reference layer: excluded from the local thickness calculation.
  • Assembly feature span: selected start and stop layers used to draw local features such as through, buried and blind vias.

Formula Basis

  • Formula basis: arithmetic stack-up thickness summation from nominal material thickness values.
  • Engineering note: lamination compression, adhesive flow and local openings should be confirmed with factory stack-up data.

Example

A 2-layer FPC can show a coverlay opening over the top layer, an air gap over the PI core, a blind via from the surface to L1, a buried via between copper layers, or a through hole across the full stack-up.

Inputs

  • Calculation zone
  • Layer name
  • Layer material type
  • Zone state
  • Layer thickness
  • Layer enabled state
  • Assembly feature type
  • Feature X position
  • Feature width
  • Feature start layer
  • Feature stop layer
  • Feature drag, resize, duplicate and flip controls

Outputs

  • Zone stack-up thickness
  • Material thickness
  • Air-gap thickness
  • Feature span thickness
  • Thickness in mil
  • Quick bend radius reference
  • Editable stack-up feature drawing
  • Copyable PNG diagram for PPT

Engineering Notes

  • Adhesive and coverlay thickness may change after lamination.
  • For connector areas, include stiffener and bonding adhesive in the local thickness.
  • For coverlay openings, removed layers are shown for review but excluded from the zone total.
  • For air-gap bend areas, the gap keeps geometric spacing while contributing no material thickness.
  • Dragging an assembly feature changes its board position while preserving the selected layer span.
  • Ctrl-drag duplicates an assembly feature, and double-clicking a blind via flips its stack-up direction.
  • The copy-image action exports a clean diagram without selection handles, making it suitable for PowerPoint, RFQ notes and process review documents.

Validation Checks

  • Zone thickness tolerance
  • Coverlay opening review
  • Air-gap bend-zone review
  • Through-hole span review
  • Buried-via span review
  • Blind-via direction review
  • Connector thickness match
  • Lamination review
  • PPT diagram communication

Related Manufacturing Process

  • Stack-up Design - Total thickness, dielectric spacing, symmetry, controlled impedance
  • Lamination - Lamination thickness, adhesive squeeze-out, registration, CTE mismatch

Related Calculators

FAQ

Should stiffener be included?

Include it only for local connector or support areas. Do not include stiffener when calculating a pure flex bend area.

Does lamination change the result?

Yes. The calculator gives a nominal sum. Process compression and adhesive flow should be handled with factory tolerance data.

Can this be used as an FPC stack-up drawing tool?

Yes. It is designed to calculate stack-up thickness and create a practical engineering diagram with openings, air gaps and via features.

Can the diagram be pasted into PowerPoint?

Yes. Use Copy image to place a clean PNG stack-up diagram on the clipboard, then paste it into PPT, RFQ documents or design review notes.