6.18 IPC/J-STD Quick Reference

Standards form the backbone of modern electronics manufacturing, turning subjective arguments into objective, enforceable rules. IPC and J-STD references provide the common language that links design intent, assembly workmanship, and repair decisions across the factory floor. By consolidating the most-used criteria into a quick reference, this guide enables faster alignment, fewer disputes, and consistent quality across products and processes.

A.6.18.1 Read this first (how to use standards)

Hierarchy: Customer spec/drawing ➝ referenced standard (latest rev) ➝ internal SWI. When they conflict, ask—don’t guess.
Classes:
- Class 1: General.
- Class 2: Most EMS work (service life expected).
- Class 3: High performance/critical.
  Class drives acceptance limits and what’s reworkable.
Words matter: “Shall” = mandatory, “Should” = recommendation.
Evidence: quote section/table numbers in your traveler or ECN; attach photos/measurements.

A.6.18.2 Most-used standards by topic (one page you can live on)

Topic	What you’re deciding	Go-to standard(s)	Quick cue (floor language)
Workmanship – assemblies	Visual accept/reject for solder, parts, labels	IPC-A-610	Class 2/3 callouts for fillets, lead protrusion, cleanliness, cosmetics
Soldering process requirements	Materials, methods, acceptability	J-STD-001	Defines what “acceptable solder joint” means and the process to get it
Rework & repair	How to remove/replace parts & pads	IPC-7711/7721	Approved methods; what’s repairable at your Class
PCB fabrication acceptance	Finished bare board quality	IPC-6012 (+ 600 visual)	Hole wall, plating, solder mask, annular rings, bow/warp
PCB design rules (generic)	Creepage/clearance, trace/space, vias	IPC-2221/2222	Baseline design constraints; pair with stackup data
Land patterns	Pad sizes/courtyards	IPC-7351	Footprints that print/reflow well; courtyard A/B/C
Stencil design	Apertures, reductions, step rules	IPC-7525	Area/aspect ratios, windowpane/home-plate tips
Solderability test – components	Plating wetting quality	J-STD-002	Dip/plate test methods & criteria
Solderability test – PCBs	Finish wetting quality	J-STD-003	HASL/ENIG/OSP solderability checks
Moisture sensitivity	MSL labels, floor life, bake	JEDEC J-STD-033, J-STD-020	Handling & reflow classification for ICs
ESD control	Program elements & audits	ANSI/ESD S20.20	Zones, grounding, PPE, compliance checks
Cable & wire harness	Acceptability classes	IPC/WHMA-A-620	Crimps, solder lugs, lacing, overmold acceptance
Conformal coating	Materials, qualification	IPC-CC-830	What “good coating” looks like; test methods
Cleanliness (ionic)	Process residue control	J-STD-001 + IPC-TM-650 methods	ROSE/SIR per method; control by process, not guesswork
Traceability	Depth, labels, genealogy	IPC-1782	Lot vs unit serialization levels
Component labeling/marking	Polarity, orientation marks	IPC-A-610, JEDEC JESD refs	Pin-1, polarity, readable designators
Press-fit	Acceptance for compliant pins	IPC-A-610, IPC-9797 (guidance)	Hole prep, insertion, inspection cues
Solder joint reliability (guidance)	Thermal/shock behavior	IPC/JEDEC-9701/9702/9703/9704	Use for qual—not daily line calls

Tip: keep IPC-A-610 + J-STD-001 + 7711/7721 at every line PC. Those three solve 80% of arguments.

A.6.18.3 Fast acceptance cues (Class 2 unless noted)

(Always verify numbers in the current standard—use this as memory joggers.)

Feature	What you look for	Where to confirm
Through-hole solder (leaded)	Smooth, concave fillet; evidence of wetting; proper lead protrusion; no icicles/voids	IPC-A-610 (THT sections) / J-STD-001
SMT gull-wing	Toe/heel/wet fillets formed; full side wetting; no lift/bridge	IPC-A-610 (SMT)
QFN/DFN	Side wetting or meniscus at edges; center pad % coverage in range; no edge shorts	IPC-A-610 + J-STD-001 notes
BGA	Ball collapse consistent; no head-in-pillow; X-ray voiding within limit	IPC-A-610 (BGA), J-STD-001 (voiding % guidance)
Cleanliness (ionic)	Process verified by method (ROSE/SIR) within program limits	J-STD-001 + IPC-TM-650
Conformal coat	Uniform coverage; protected keepouts; no bubbles/bridges where forbidden	IPC-CC-830 + IPC-A-610 coating section
Wires/terminals	Correct strip length; barrel fill; insulation support; pull-test	IPC/WHMA-A-620
Labels/marking	Legible, durable, correct location; no bridging seams	IPC-A-610 general; your label spec

A.4 Quick “which Class?” cheat (when customers don’t specify)

Consumer/office gear: default Class 2.
Industrial controls, telecom base, pro A/V: Class 2 (sometimes Class 3 for safety-critical).
Avionics, medical life-support, downhole, military: Class 3 unless the contract says otherwise.

When in doubt, ask and document the decision in the traveler.

A.5 Inspection & rework triad (who governs what)

Situation	Use this standard first	Then this
Is it acceptable as built?	IPC-A-610	Customer spec/drawing
Can we build it this way?	J-STD-001	Process doc / supplier data
Can we repair it (and how)?	IPC-7711/7721	Customer waiver if Class 3 & critical

A.6 Handy cross-refs for daily questions

“What footprint should I use?” → IPC-7351 (land pattern), then your paste aperture rules (IPC-7525).
“Board finish good enough to assemble?” → J-STD-003 (PCB solderability).
“Parts wetting okay?” → J-STD-002 (component solderability).
“How clean is clean?” → J-STD-001 program + IPC-TM-650 method callout.
“Harness crimp looks short—reject?” → IPC/WHMA-A-620 figure & table.
“Coating blobs near connector—okay?” → IPC-CC-830 + IPC-A-610 coating keepouts.
“What trace/space & creepage can I use?” → IPC-2221/2222 with your voltage/environment.

A.7 Pocket checklist (how to cite standards in your build)

Class specified on traveler (1/2/3).
Latest rev confirmed in the cell library/PLM.
SWIs reference exact section/table numbers (not just the book title).
Rework tickets cite 7711/7721 method IDs.
Incoming/FAI forms list J-STD-002/003 when solderability is in scope.
Coating/cleaning steps cite CC-830 and TM-650 methods where required.
Traceability depth matches IPC-1782 level in the control plan.

Using standards with discipline—quoting exact clauses, applying the correct Class, and documenting decisions—keeps builds defensible and repeatable. The result is fewer delays, less ambiguity, and a smoother path from production to customer acceptance.