PCB Tolerance Standards
This page summarizes common printed circuit board manufacturing tolerances for standard PCB production. If your design requires tighter tolerances, impedance control, heavy copper, or special process control, please contact us before placing the order.
General Standard Tolerance Overview
| Item | Standard Tolerance |
|---|---|
| Board Outline Dimension | ±0.15mm (±0.006") |
| Board Thickness | ±10% of finished thickness |
| Finished Hole Diameter | ±0.08mm (±0.003") |
| Hole Position Accuracy | ±0.075mm (±0.003") |
| Minimum Trace Width / Spacing Control | Subject to ordered specification and production capability |
| Copper Thickness | Typically within ±10% |
| Solder Mask Registration | ±0.075mm (±0.003") |
| Silkscreen Registration | ±0.15mm (±0.006") |
| Surface Finish Thickness | According to process standard and material specification |
| Warp and Twist | ≤0.75% for standard boards unless otherwise specified |
Note: Tolerance capability may vary depending on PCB thickness, copper weight, layer count,
panel size, material type, and special processing requirements.
Drilling and Hole Tolerance
| Item | Typical Capability |
|---|---|
| Mechanical Drill Hole Diameter | Finished size tolerance typically ±0.08mm |
| Via Hole Registration | Controlled by drilling and layer alignment process |
| Plated Through Hole (PTH) Copper | Produced to standard plating requirement |
| Non-Plated Through Hole (NPTH) | Processed separately according to fabrication data |
For designs with press-fit holes, tight connector fit, or special mechanical assembly requirements,
tighter tolerance control must be confirmed before production.
Board Thickness and Copper Tolerance
| Item | Standard |
|---|---|
| Finished Board Thickness | Usually ±10% |
| Outer Layer Copper Thickness | Based on ordered copper weight and plating process |
| Inner Layer Copper Thickness | Based on base laminate copper specification |
| Heavy Copper Board | Needs special review; tolerance may be wider |
Actual finished thickness can be influenced by prepreg structure, copper distribution,
resin content, and final surface finish.
Solder Mask, Silkscreen and Routing Tolerance
| Item | Standard Tolerance |
|---|---|
| Solder Mask Registration | ±0.075mm |
| Silkscreen Registration | ±0.15mm |
| Routing / CNC Outline | ±0.15mm |
| V-Cut Alignment | Subject to panel design and board structure |
| Edge to Copper Clearance | Should follow DFM recommendation |
- Solder mask dam capability depends on trace spacing and mask process.
- Very small silkscreen text may become unclear after production.
- Special edge plating, castellated holes, or half-holes require separate review.
Special Tolerance Requirements
The following requirements are not recommended to assume as default standard. They should be clearly stated in your Gerber notes, fabrication drawing, or order comments:
- Controlled impedance tolerance
- Tight hole-to-hole positional tolerance
- Special board thickness tolerance tighter than ±10%
- Press-fit connector hole tolerance
- Heavy copper or asymmetric copper balance control
- Rigid-flex or flex PCB special dimensional tolerance
- Special flatness requirement for assembly or BGA application
If your PCB has critical mechanical or electrical requirements, please send the fabrication drawing for engineering review before order confirmation.