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Turn Your Stackup Preview into a Manufacturing Build

A stackup preview is useful during early design, but production impedance depends on the fabricator’s actual laminate, copper thickness, dielectric spacing, and process tolerances.

Send us your target impedance, layer count, material preference, and board quantity. Contact us for all your PCB, PCBA, and custom service needs!

PCB

PCB Stack-up Builder

Engineering Tools — Impedance Preview
Impedance Preview
Layer Stack
4
Copper Layers
1.57
Total (mm)
2
Signal Layers
2
Plane Layers
Cross-Section & Impedance
Trace Parameters for Impedance
Calculated Impedance
Stack-up Notes
Standard 4-layer stack-up. Suitable for mixed-signal designs up to 1 GHz.

PCB Stack-up Design Guide

A well-designed PCB stack-up is crucial for signal integrity, EMI control, and manufacturability. The arrangement of signal and plane layers, along with dielectric materials, determines impedance, crosstalk, and power delivery performance.

Microstrip: Z₀ ≈ (87 / √(εᵣ + 1.41)) × ln(5.98h / (0.8w + t))

Stripline: Z₀ ≈ (60 / √εᵣ) × ln(4h / (0.67π × (0.8w + t)))

Where εᵣ is dielectric constant, h is height to reference plane, w is trace width, and t is copper thickness. Accurate within ~5% for typical PCB geometries.

Common Dielectric Materials
  • FR4 Standard — εᵣ = 4.2–4.5, low cost
  • High-Speed FR4 — εᵣ = 3.8–4.0, better Df
  • Rogers 4350B — εᵣ = 3.48, RF/microwave
  • Megtron 6 — εᵣ = 3.4, high-speed digital
Layer Pairing Rules
  • Signal layers should reference solid planes
  • Keep high-speed signals adjacent to GND
  • Avoid routing over plane splits
  • Balance copper symmetrically to prevent warpage
Impedance Targets
  • 50Ω — Single-ended (USB, SPI, general)
  • 90Ω — Differential (USB 2.0/3.0)
  • 100Ω — Differential (Ethernet, LVDS)
  • 85Ω — Differential (HDMI, DisplayPort)
Manufacturing Tolerances
  • Impedance: ±10% standard, ±5% tight
  • Dielectric thickness: ±10%
  • Trace width: ±0.5–1.0 mil
  • Registration: ±2–3 mils layer-to-layer

Design Tip: For controlled impedance, always consult your fabricator's capabilities and request their recommended stack-up. Actual impedance depends on their specific materials and processes. This calculator provides estimates for early design planning.