Manufacturing Tolerance
Inner Layer Hole to Copper
Tolerance: Hole size + 0.020”
Design Tip: Ensure that holes for both vias and components do not come within 0.010” of copper from a different net.
Hole Location (Annular Ring, Pad Size)
Tolerance: +/- 0.003”
Design Tip: Pads for plated holes must be at least 0.010” larger than the plated hole to ensure an IPC 6012 annular ring.
Board Outline
Tolerance: +/- 0.005”, unless a scored array is required (see below)
Design Tip: Keep outer layer copper at least 0.005” away from the board edge and inner layer copper at least 0.010” away from the board edge.Leave more space on the inner layers because inner layers can shift and because the pre-preg needs to adhere to the layers above and below.Some exceptions are necessary, such as gold fingers, which usually meet the board edge.
Scoring
Locational Tolerance: +/- 0.003”
Depth tolerance: +/- 0.005”
Design Tip: Use these tolerances and some trigonometry to determine how close your copper can come to a scored edge.Remember that the center of the score line is the edge of your board.
Hole Size
Tolerance: +/- 0.003” for plated holes less than 0.247” in diameter, +/- 0.002” for nonplated holes less than 0.250” in diameter, +/- 0.005” for larger holes
Slots
Tolerance: +/- 0.005”
Internal Cutouts
Tolerance: +/- 0.005” nonplated, +/- 0.010” plated
Thickness
Tolerance: +/- 10% or +/- 0.005”, whichever is greater
Trace Width
Tolerance: +/- 20%
Copper-to-Copper Spacing
Tolerance: +/- 20%
Soldermask Registration
Tolerance: +/- 0.003”
Depth tolerance: +/- 0.005”
Design Tip: Soldermask clearances should be 0.003” larger than their pads (this distance is sometimes called a “soldermask swell”).With a standard minimum soldermask dam of 0.004”, components whose pads are within 0.010” of each other may require special processing.
