US Full Feature PCBs

Tolerances and Design Requirements

1. Inner Layer Clearances
   We require a minimum of 0.010” inner layer clearance.
   
   
2. Copper to Edge of Printed Circuit Board
   Minimum of 0.010” (outer layers) and 0.014” for inner layers (0.020” preferred for inner layers). For scoring, minimum of .015 for outer layers and .020 for inner layers.
   
   
3. Pad Size/Annular Ring
   Pad size should be at least + 0.010” over finished hole size for vias and + 0.014” over finished hole size for component holes. This means the annular ring (radius of the pad) should be at least .005” for vias and a minimum of 0.007” for component holes.
   
   
4. Hole Size
   +/- 0.005”  Standard Spec
   +/- 0.005” Custom Spec default
   +/- 0.003” Custom Spec upon request 1 oz and 2 oz finished copper weight only
   Minimum finished hole size; 0.010”. Call your salesperson if you required a finished hole size less than 0.010”.
   
   
5. Printed Circuit Board Thickness
   Overall may vary +/- 10% (Minimum +/- 0.005”)
   Minimum finished thickness for 2-layer: 0.005” (Call if you need a thickness of less than 0.005”)
   Minimum finished thickness for 4-layers: 0.020”
   Minimum finished thickness for 6-layers: 0.031”
   Minimum finished thickness for 8-layers: 0.047”
   Minimum finished thickness for 10-layers: 0.062”
   
   
6. Inner Layer Thickness
   Tolerances do not apply to the inner layers of Standard Spec Orders.
   
   
7. Rout (Board Outline)
   +/- 0.010” (+/- 0.005” available for Custom Spec Orders upon request
   Note: We rout to your board size using the center of the board outline on your mask layer.
   
   
8. Copper Trace Width/Spacing
   This is the minimum air gap between any two adjacent copper features. Trace width is the minimum width of a copper feature, usually traces.
   For trace width/spacing, we require a minimum of 0.005” for 1 oz. finished copper weight on outer layers. Premiums are added for trace/space specs less than 0.008”
   For 1 oz. finished copper weight (inner layers), minimum trace width/space is 0.005”
   For 2 oz. finished copper weight (inner & outer), minimum trace width/space is 0.007”
   For 3 oz. finished copper weight (inner & outer), minimum trace width/space is 0.010”
   For 4 oz. f inished copper weight (inner & outer), minimum trace width/space is 0.012
   
   
9. Conductor width, thickness and spacing
   When not specified by the customer, the minimum conductor width shall be 80% of  the pattern supplied by the procurement documentation.  Both internal and external conductor conductor  thickness  tolerance  vary with the weight of the copper foil used for fabrication and  must    meet or exceed values established by IPC-6012.  Conductor  spacing may be reduced by a maximum of 30% (IPC Class2) unless otherwise stated in the documentation.
   
   
10. Soldermask Swell
    This is the expansion of mask relief over pad area. Our minimum is 0.005” over pad dimension or 0.0025” each side. PCB Unlimited will modify files to meet the minimum dimension.
    
    
11. Slot Width
    Minimum 0.031” in width. For smaller width, call your salesperson for pricing and turntime.
    
    
12. Tab Rout Spacing
    Please allow 0.100” spacing between your individual pcbs for tab rout spacing. When scoring there should be no spacing between boards.
    
    
13. Silkscreen (Legend)
    0.005” minimum line width.