Contact Sales & After-Sales Service

Contact & Quotation

  • Inquire: Call 0086-755-23203480, or reach out via the form below/your sales contact to discuss our design, manufacturing, and assembly capabilities.
  • Quote: Email your PCB files to Sales@pcbsync.com (Preferred for large files) or submit online. We will contact you promptly. Please ensure your email is correct.
Drag & Drop Files, Choose Files to Upload You can upload up to 3 files.

Notes:
For PCB fabrication, we require PCB design file in Gerber RS-274X format (most preferred), *.PCB/DDB (Protel, inform your program version) format or *.BRD (Eagle) format. For PCB assembly, we require PCB design file in above mentioned format, drilling file and BOM. Click to download BOM template To avoid file missing, please include all files into one folder and compress it into .zip or .rar format.

Dielectric Thickness Calculator - PCBsync

Dielectric Thickness Calculator

PCBsync Engineering Tools
Impedance Design
Input Parameters
Trace Configuration
Target Impedance 50 Ω
Trace Width 0.15 mm
Copper Thickness 1 oz (35µm)
Dielectric Material εᵣ = 4.3
Custom εᵣ (Override) 4.3
Solder Mask
Calculated Results
Required Dielectric Thickness
0.185
mm
7.3 mils | 185 µm
Effective εᵣ
3.28
W/H Ratio
0.81
Propagation Delay
6.04 ps/mm
Loss @ 1GHz
0.12 dB/cm
Prepreg Style Resin % Thickness Match
Recommended Stack-up
For 50Ω microstrip with 0.15mm trace on FR4, use 1x 7628 prepreg (0.185mm) or 2x 2116 prepreg (0.19mm combined). Verify with your fab house.
Standard prepreg available for this configuration
Calculation Notes
Microstrip calculation using IPC-2141 approximation. Trace: 0.15mm width, 35µm copper on FR4 (εᵣ=4.3). Solder mask effect included. Manufacturing tolerance: ±10% typical.

Understanding Dielectric Thickness for Impedance Control

The dielectric thickness (height between trace and reference plane) is a critical factor in determining trace impedance. For a given trace width and material, adjusting dielectric thickness is often the most practical way to achieve target impedance. This calculator helps you determine the required thickness or verify impedance for a given stack-up.

Microstrip: h = (5.98 × w) / (e^(Z₀ × √(εᵣ + 1.41) / 87) - 0.8w - t)

Stripline: h = (0.67π × (0.8w + t) × e^(Z₀ × √εᵣ / 60)) / 4

Where h is dielectric height, w is trace width, t is copper thickness, εᵣ is dielectric constant, and Z₀ is target impedance. These are rearrangements of standard impedance equations to solve for height.

Common Prepreg Styles
  • 1080 — 0.065mm (2.5 mil), fine glass
  • 2116 — 0.095mm (3.7 mil), standard
  • 1506 — 0.130mm (5.1 mil), medium
  • 7628 — 0.185mm (7.3 mil), thick
Core Thickness Options
  • 0.1mm (4 mil) — Thin core, HDI
  • 0.2mm (8 mil) — Standard thin
  • 0.36mm (14 mil) — Common 6-layer
  • 0.71mm (28 mil) — Standard 4-layer
εᵣ Effects on Design
  • Higher εᵣ → thinner dielectric needed
  • Higher εᵣ → slower signal propagation
  • Lower εᵣ → better high-frequency performance
  • εᵣ varies with frequency (dispersion)
Manufacturing Considerations
  • Prepreg compresses 10-15% after lamination
  • Combine prepregs to achieve target thickness
  • Resin content affects final εᵣ
  • Always request fab house stack-up review

Pro Tip: The effective dielectric constant (εᵣ,eff) for microstrip is lower than bulk εᵣ because some field lines travel through air. This calculator accounts for this effect. For stripline (buried between planes), the full εᵣ applies since the trace is fully enclosed in dielectric.

Contact Sales & After-Sales Service

Contact & Quotation

  • Inquire: Call 0086-755-23203480, or reach out via the form below/your sales contact to discuss our design, manufacturing, and assembly capabilities.

  • Quote: Email your PCB files to Sales@pcbsync.com (Preferred for large files) or submit online. We will contact you promptly. Please ensure your email is correct.

Drag & Drop Files, Choose Files to Upload You can upload up to 3 files.

Notes:
For PCB fabrication, we require PCB design file in Gerber RS-274X format (most preferred), *.PCB/DDB (Protel, inform your program version) format or *.BRD (Eagle) format. For PCB assembly, we require PCB design file in above mentioned format, drilling file and BOM. Click to download BOM template To avoid file missing, please include all files into one folder and compress it into .zip or .rar format.