Welcome to Entech Electronics Inc

Printed Circuit Board

PCB Tolerances & Specifications

Manufacturing capability for single, double sided and multilayer printed circuit boards. Where tighter tolerances are required then these must be referred to Entech’s Customer Liaison Engineers.

 

  1. BOARD SIZES – PLATED THROUGH HOLE.
    Maximum Board Dimensions 22.5” x 16” (571.5mm x 406.4mm)
    Minimum Board Dimensions 0.5” x 0.25” (12.7mm x 6.35mm)
    Maximum Print & Etch 32” x 25” (812mm x 635mm)
  2. BOARD SIZES MULTILAYER.
    Maximum Board Dimensions 21” x 15” (533.4mm x 381mm)
    Minimum Board Dimensions 1” x 0.5” (25.4mm x 12.7mm)
  3. MINIMUM PLATED HOLE DIAMETERS.
    Minimum diameter plated through component hole 0.024”
    Minimum diameter plated through via hole 0.008”
    Note: Via holes may block during plating or solder coating and hence are not subject to tolerance limits.
  4. HOLE DIAMETERS TOLERENCES RANGE - DRILLED HOLES.
    Up to 1.00mm ± 0.025mm
    1.00mm to 2.00mm ± 0.038mm
    Above 2.00mm ± 0.05mm
  5. HOLE DIAMETERS TOLERANCE RANGE PLATED THROUGH HOLES.
    Up to 1.00mm ± 0.05mm
    1.00mm to 2.00mm ± 0.075mm
    Above 2.00mm ± 0.087mm
  6. DRILLED HOLE POSITIONAL TOLERANCE.
    Located from films 0.006”
    Derived from CAD tape, outer layers 0.003”
  7. MACHINE CUTTING TOLERANCE.
    NC Routing ± 0.010”
    Standard Router 0.079”
    Minimum Router 0.032”
    V-groove (center of V to nearest feature) 0.032” (0.8mm)
  8. PLATING THICKNESS CONTROL.
    Acid Copper Plating.
    ± 15% Dependant on area distribution.
    Each batch is measured for plated through hole copper thickness by non-destructive testing and a statistical profile is kept on record.
  9. REGISTRATION TOLERANCE (PAD/HOLE RATIO).
    Finished minimum Annular Ring is 0.001” based on a minimum circuit pad of drilled hole diameter plus 0.012”, 0.016” preferred. Holes classified as via holes, may have pad breakout except at the track to pad junction - we suggest use of teardrop or filleted pads.
    Inner layer clearance requirements are drilled hole size plus 0.020” minimum, 0.024” preferred.
  10. REGISTRATION TOLERANCE SOLDER RESIST.
    Photo liquid imageable solder mask 0.006” oversize
    Minimum Soldermask web between SMD pads 0.006”
  11. NOTATION COMPONENT CODE.
    Alignment positional tolerance ± 0.008”
  12. MINIMUM TRACK WIDTHS AND SPACINGS.
    Minimum conductor width 0.006”
    Minimum conductor spacing 0.006”
    Note: Dependant on copper weight specified.
  13. FINISHES AVAILABLE.
    Solder Leveled
    Copper
    Gold
    Electroless Nickel/Immersion Gold, for SMD applications
    Graphite/Carbon Ink
    Immersion Silver
  14. SOLDER MASKS AVAILABLE.
    Photo imageable solder mask in various colours
    UV soldermask
    Peelable solder mask
  15. BARE BOARD TESTING.
    Entech has the following “in-house” Bare Board Electrical Test capability.     Trace Series 9090 Universal Bare Board Tester.
    Netlist Testing using Lavenir Test Fixture Software.
    Fixturing system software gives double sided SMD test capability.
    Active test points 20,480 (16” x 12.8”) on the primary side & 10,240 active test points on the secondary side.
    For Double sided testing configured as 15360 test points on bottom(12.6”x12.0”) and 12288 test points on the top side ( 12.6”x9.6”). Isolation Stimulus Voltage 10V to 250V.
    Continuity resistance 1 Ohm – 10 K Ohms.
    Isolation resistance is programmable to 10K to 100 MegOhms
    Pitch 0.020”
    ATG3 Flying Probe Testers.
    Fixtureless.
    Maximum Board Size- 24”x18”
    Maximum Test Area- 20.4” x 15.7”
    Optical Registration.
    Continuity resistance from 1 Ohm
    Test Voltage- to 500V/ 100 MOhm.
    Resistance- 10 Ohm to 50 Mohms.
    Smallest Test pad- 0.004”.
    Fault Verification/ Repair and Retest
  16. BASE LAMINATES USED.
    Epoxy woven glass prepregs, copper clad FR4. Other substrates such as Teflon etc., available on request.
  17. APPROVALS HELD BY ENTECH
    Quality endorsed to ISO 9002. QEC 200.
    Printed Circuit Boards Flammability Rating UL 94 VO Approval. UL 796 Printed Wiring Boards. File No. E137389.
    UL File has been extended to provide Canadian CSA Approval. PCB Assemblies- UL approved for some customers builds. PCB Assemblies CSA approved for selected customer builds.
  18. AUTOMATED TOOLING SYSTEM.
    Gerber Photoplotter.
    EMU Panellisation System.
  19. MACHINING.
    NC Drilling – NC Routing, NC – Milling, “V” Grooving – Edge Beveling.
  20. ADDITIONAL FEATURES.
    Membrane switches, Decals, specialist screen printers, digital printing, Wave soldering, Automated SMD assembly, solder paste stencils, exotic substrates, flexibles, NC Milling.
  21. BATCH SIZES.
    Minimum quantity – one.
    Maximum quantity – negotiable.