PCB Inspection Services


You may have noticed, we're a bit obsessed with delivering excellent quality and exceptional service. In an effort to insure we meet our own high standards — and yours — Sunstone has adopted an inspection program using the IPC-A-600 Rev H as our guide. This industry specification is the pictorial guide for the acceptability of printed circuit boards. This method of inspection is our default inspection method for all products. If your needs differ from these standards please inquire or use Custom Quote to order IPC-6012 class II or III compliant boards.

IPC-A-600 and IPC-6012 Inspection Items

The following chart shows the IPC-A-600H (or its supporting document IPC-6012) inspection item and its call-outs. The Sunstone inspection column gives the Sunstone method of compliance.

IPC (Institute of Interconnecting and Packaging Electronic Circuits) publishes the IPC-A-600 Rev H pictorial guide.

Notes for IPC PCB Inspection Standards

*We seek to use the standard’s classification and defect determinations to maintain a “Class II” quality level. We have elected to use an adapted inspection system to maintain production quality. Our quality program, sampling plans, coupon use, record keeping, and use of outside labs is different than the IPC-6012.

Characteristic IPC-600G Guideline * Sunstone Inspection
Board edges
  • Haloing and nicks maximum 0.100" or 50% of distance to nearest conductor, whichever is less.
  • Final inspection
Bow and twist
  • General 1.5% max.
  • SMT boards 0.75%. max.
  • Final inspection
Conductor thickness
  • Table 3-9 (external)
  • Table 3-8 (internal)
  • Measurement made at post etch inspection
  • Measurement made at post etch inspection
Copper plating thickness,
minimum in holes
  • Class 2, avg. 0.0008" , thin spots 0.0007"
  • Class 3, avg. 0.001", thin spots 0.0008" (Table 3-2)
  • Sample of holes measured by PTX to determine average plated hole thickness.
Copper plating voids
  • Class 2 - One Cu void allowed per hole in not more than 5% of the holes.
  • Class 3 - No Cu voids allowed.
  • Shall not exceed 5% of hole length or 90° of circumference (Table 3-3)
  • Sample visual inspection after etching· cross section referee
  • Sample visual inspection after etching· cross section referee
Delamination/blisters
  • Evaluated in accordance with IPC-A-600
  • Class 1 now same as Class 2, 3 (2.3.3)
  • Evidence of delamination in micro section now refers to 2.3.3 instead of being automatically nonconforming (3.1.4)
  • Post-final surface finish inspection / final inspection
Solder Dewetting
  • Ground planes and traces: allowed
  • Solder connection areas: max. 5% (Class 2, 3)
  • Post-final surface finish inspection / final inspection
Finish plating voids
  • Class 2 - Three solder voids allowed per hole in not more than 5% of the holes.
  • Class 3 - One solder void per hole in not more than 5% of the holes.
  • Shall not exceed 5% of hole length or 90° of circumference (Table 3-3)
  •  Post-final surface finish inspection / final inspection
Foreign inclusions
  •  Evaluated in accordance with IPC-A-600, except no maximum dimension specified (3.3.2.1)
  • Post-final surface finish inspection
Gold thickness
  •  Class 2 - min. 30µ"· Class 3 - min. 50µ"· Solderable gold - 30µ" maximum.
  • Beta-backscatter or XRF measurement on sample after gold plating
Hole location
  • As specified on procurement document.
  • In-process visual inspection (after etching, before mask)
Hole sizes
  •  ±0.005" for plated through holes, ±0.003" for non-plated through holes, +0.003" / - hole size for vias, unless otherwise specified by customer
  • Hole sizes not verified for Express product. All other product lines: plug gauge measurements made.
Solder Mask coverage
  • See 3.8.1
  • Post-final surface finish inspection
Solder Mask cure &
adhesion
  • No tackiness
  • Blisters/delamination: 2 per side, max. 0.010 in, does not reduce spacing by more than 25%
  • Soda-strawing is now defined as applying to DFSM only (2.9.9)
  • Post-final surface finish inspection
Solder Mask in holes
  • Allowed only in holes in which are not to be soldered.
  • Post-final surface finish inspection
Solder Mask registration
  • Post-final surface finish inspection
Solder Mask thickness
  • Visual coverage; no thickness requirement
  • Not checked unless specifically required by drawing
Solder Mask touch-up
  • Touch-up material specified (IPC-A-600G 2.9.1)
  • Post-final surface finish inspection
Measles/crazing
  • Evaluated in accordance with IPC-A-600
  • Measles acceptable for all except high voltage applications [not defined] (2.3.1)
  • Crazing spec. now same as delamination except 50% of distance between conductors may be spanned; also now shows pictures of crazing (2.3.2)
  • In-process inspection (after etch, before solder mask)
Min. ann. ring NPTH
  • Class 2: No breakout allowed.
  • Final inspection
Min. ann. ring-internal
  • Class 2: 90° breakout allowed
  • Process control using etched drill panel (selecting the design review option ensures design is within capability).
Min. external ann. ring - PTH
  •  Class 2: 90° breakout allowed except at junction of pad and trace, where .002" minimum is allowed.
  • In-process inspection (after etch, before mask). Selecting the design check option ensures design is within capability.
Nomenclature (silkscreen)
  •  Refers to IPC-A-600 for legibility requirements Marking ink on surface mount lands no longer nonconforming (IPC-A-600G 2.8.3)
  • Final inspection
Nonwetting
  • None allowed
  • Post-final surface finish inspection
Pink ring
  • Acceptable (3.3.2.6)
 
Pits and voids in base material
  • Acceptable if no larger than 0.8 mm [0.03 in] and no more than 5% of board area
  • Post-final surface finish inspection
Plating adhesion
  • Tape test required (slivers coming off with tape is not cause for rejection)
  • In-process inspection (after etch, before mask)
Plating cracks
  • See Table 3-7 (basically none allowed)
  • In-process visual inspection (after etch, before mask) cross section referee
Resin fill of blind/buried vias
  • Buried vias shall be at least 60% filled with resin (3.3.14)
  • Not applicable
Routing tolerances
  • As specified on procurement document.
  • Final inspection; sample checked per customer drawing or default to ±.010
Spacing reduction
  •  When not specified on the customer's documentation, 30% allowed for class 2; 20% allowed for class 3.
  • Post-final surface finish inspection (when required)
Tenting (via holes)  
  • Post-final surface finish inspection (when required)
Tin/lead, solder coat
  • Unfused tin/lead: min. thickness 0.0003"
  • Fused or HAL: coverage and solderable.
  • Sidewalls do not have to be covered.
  • Post-final surface finish inspection
Trace width
  • Class 2, 3: When not specified on the customer's documentation, 20% max. line loss, additional 20% for isolated defects
  • In-process measurement / inspection (after etch, before mask)
Weave exposure and
exposed/disrupted fibers
  •  Acceptable for Class 1, 2, 3 as long as minimum conductor spacing is met.
  • In-process inspection (after etch, before mask)
Weave texture
  • Not addressed
  • Not applicable
Documentation Retention
  • Evidence of Inspection and / or Testing
  • Express Product 90 Days
  • PCB123 Product 90 Days
  • Full-Feature Product 3 Years