IPC-A-610 Standard Explained: Classes, Certification & Inspection Criteria [2024 Guide]

If you’ve ever rejected a board because of a solder bridge, only to have someone argue it’s acceptable for the product class, you understand why IPC-A-610 matters. Without a common reference, “good enough” becomes a matter of opinion. Arguments happen. Quality suffers. Customers lose confidence.

IPC-A-610 eliminates that ambiguity. It’s the most widely used acceptance standard in electronics manufacturing, providing illustrated criteria that define exactly what’s acceptable, what’s a process indicator, and what’s a defect—for three distinct product classes. Whether you’re inspecting consumer electronics or flight-critical aerospace assemblies, IPC-A-610 gives you the objective criteria to make consistent accept/reject decisions.

I’ve used IPC-A-610 for years as both an inspector and a quality engineer. The standard isn’t perfect—no standard is—but it provides a foundation that makes quality discussions productive rather than adversarial. This guide covers what you need to know to implement IPC-A-610 effectively: the class system, key inspection criteria, certification requirements, and how it relates to J-STD-001.

What is IPC-A-610?

IPC-A-610, officially titled “Acceptability of Electronic Assemblies,” is the global benchmark for visual inspection of assembled printed circuit boards. Developed by IPC (Association Connecting Electronics Industries), it defines acceptance criteria for the finished product—what the assembly should look like when it’s ready to ship.

The standard covers virtually every aspect of assembled electronics you can see or measure without destructive testing: solder joint quality, component placement, mechanical assembly, cleanliness, coating, marking, and damage. It uses hundreds of color photographs and illustrations to show exactly what acceptable and unacceptable conditions look like.

IPC-A-610 Revision History

Revision	Year	Key Changes
Original	1983	First release
Rev D	2000	Major reorganization
Rev E	2005	Lead-free soldering criteria added
Rev F	2007	Enhanced SMT criteria
Rev G	2017	New component types, updated graphics
Rev H	2020	Target conditions removed, new anomalies
Rev J	2024	Current revision, participants from 31 countries

The current revision is IPC-A-610J, released in March 2024. Note that there’s no revision “I”—IPC skipped it to avoid confusion with the number “1” or lowercase “L.”

What IPC-A-610 Covers

The standard is organized into chapters addressing different aspects of electronic assembly:

Chapter 1-3: Scope, applicable documents, and handling requirements Chapter 4: Hardware assembly (fasteners, connectors, heat sinks) Chapter 5: Soldering criteria (general requirements for all solder joints) Chapter 6: Terminal connections (turret, bifurcated, pierced, hook) Chapter 7: Through-hole technology (component mounting, solder fill) Chapter 8: Surface mount technology (chip components, leaded, BGA) Chapter 9: Component damage (acceptable vs. rejectable damage) Chapter 10: PCB assembly conditions (laminate, conductors, markings) Chapter 11: Cleanliness and residue Chapter 12: Coating (conformal coating inspection) Chapter 13: Discrete wiring

What IPC-A-610 Does NOT Cover

Understanding the standard’s scope prevents misapplication. IPC-A-610 does NOT define:

• Bare board acceptance — That’s IPC-A-600
• Soldering processes — That’s J-STD-001
• Design requirements — That’s IPC-2221/2222 series
• Materials specifications — Covered by other standards
• Electrical testing — Functional test is separate from visual inspection
• Wire harness assemblies — That’s IPC/WHMA-A-620

IPC-A-610 assumes the bare board meets IPC-A-600 criteria and that soldering was performed according to J-STD-001. It defines acceptance criteria for the finished assembly, not the process used to create it.

IPC-A-610 Class 1, Class 2, and Class 3 Explained

The heart of IPC-A-610 is its three-class system. Each class represents different end-use requirements, with increasingly stringent acceptance criteria as you move from Class 1 to Class 3.

Class Definitions

Class 1 — General Electronic Products Products where the primary requirement is function of the completed assembly. Cosmetic imperfections are acceptable if the assembly works. These products typically have limited life expectancy and simple functionality.

Class 2 — Dedicated Service Electronic Products Products where continued performance and extended life are required, and for which uninterrupted service is desired but not critical. Some cosmetic imperfections are acceptable, but workmanship standards are higher than Class 1.

Class 3 — High-Performance/High-Reliability Electronic Products Products where continued high performance or performance-on-demand is critical. Equipment downtime cannot be tolerated, the end-use environment may be harsh, and the product must function when required. Highest workmanship standards apply.

IPC-A-610 Class Comparison

Aspect	Class 1	Class 2	Class 3
Primary Focus	Function	Function + Extended Life	Continuous High Reliability
Cosmetic Requirements	Minimal	Moderate	Stringent
Solder Joint Criteria	Basic	Standard	Most demanding
Component Placement Tolerances	Widest	Moderate	Tightest
Typical Cost Impact	Lowest	Moderate	Highest
Inspection Time	Shortest	Moderate	Longest
Documentation Requirements	Basic	Standard	Comprehensive

Which Class Should You Use?

The customer determines the class, not the manufacturer. However, if no class is specified, Class 2 is typically the default for commercial/industrial products. Here’s how class selection typically aligns with applications:

Class 1 Applications:

• Disposable electronics
• Novelty items and toys
• Promotional products
• Low-cost consumer goods
• Products with < 1 year expected life

Class 2 Applications:

• Consumer electronics (TVs, computers, smartphones)
• Industrial controls and automation
• Commercial telecommunications
• Office equipment
• Automotive infotainment
• Home appliances

Class 3 Applications:

• Aerospace and defense systems
• Medical life-support equipment
• Implantable medical devices
• Space flight hardware
• Critical automotive safety systems (braking, airbags)
• Nuclear facility controls
• Military weapon systems

The Cost of Class Selection

Higher classes cost more—sometimes significantly more. Class 3 requirements mean slower production, more inspection time, higher reject rates, and more documentation. A board that passes Class 2 inspection might fail Class 3, requiring rework that adds cost without adding functionality.

Don’t over-specify. If your product is a consumer appliance with a 5-year expected life, Class 3 requirements add cost without corresponding benefit. Conversely, under-specifying for critical applications creates liability and reliability risks.

Key IPC-A-610 Inspection Criteria

Let’s examine the acceptance criteria that quality engineers and inspectors apply most frequently.

Solder Joint Inspection Criteria

Solder joints are the most common inspection focus. IPC-A-610 defines acceptable solder joint characteristics including wetting, fillet formation, and surface appearance.

Acceptable Solder Joint Characteristics:

• Good wetting to both the lead and pad
• Smooth, shiny, or satin finish (lead-free solder may appear grainy/matte)
• Concave fillet shape showing evidence of wetting
• Lead/termination outline visible through solder
• No cracks, fractures, or disturbed joints

Common Solder Defects:

Defect	Description	Class 1	Class 2	Class 3
Insufficient solder	Fillet doesn’t meet minimum requirements	Defect	Defect	Defect
Excess solder	Lead/termination outline not visible	Acceptable	Process Indicator	Defect
Solder bridge	Unintended solder connection between conductors	Defect	Defect	Defect
Cold joint	Grainy, dull appearance with poor wetting	Defect	Defect	Defect
Disturbed joint	Evidence of movement during solidification	Defect	Defect	Defect
Nonwetting	Solder doesn’t adhere to surface	Defect	Defect	Defect
Dewetting	Solder recedes after initial wetting	Defect	Defect	Defect

Through-Hole Component Criteria

For through-hole components, IPC-A-610 specifies requirements for component mounting, lead protrusion, and solder fill.

Lead Protrusion Requirements:

Class	Minimum Protrusion	Maximum Protrusion
Class 1	Lead visible in hole (solder side)	2.5 mm (0.098″)
Class 2	Lead visible in hole (solder side)	2.5 mm (0.098″)
Class 3	0.5 mm (0.020″) minimum	1.5 mm (0.059″) preferred

Vertical Solder Fill Requirements (Unsupported Holes):

Class	Primary Side	Secondary Side
Class 1	180° wetting	180° wetting
Class 2	270° wetting	180° wetting
Class 3	330° wetting	270° wetting

Read more IPC Standards:

Surface Mount Component Criteria

SMT inspection involves evaluating placement accuracy, solder joint formation, and component orientation.

Chip Component (Resistors, Capacitors) Placement:

Condition	Class 1	Class 2	Class 3
Side overhang (A)	≤ 50% W	≤ 50% W	≤ 25% W
End overhang (B)	≤ 50% W	≤ 50% W	Not allowed
End joint width (C)	≥ 50% W	≥ 50% W	≥ 75% W
Side joint length (D)	Some evidence	Some evidence	≥ 50% L

Where W = component width, L = component length

Gull-Wing Lead Criteria:

Measurement	Class 1	Class 2	Class 3
Heel fillet	Not required	Not required	Required, visible
Toe fillet	Some evidence	Some evidence	Evidence of wetting
Side joint length	≥ 50% lead width	≥ 50% lead width	≥ 75% lead width
Maximum side overhang	50% lead width	50% lead width	25% lead width

Component Damage Criteria

IPC-A-610 Chapter 9 defines acceptable levels of component damage. Some damage is acceptable depending on severity and class.

Body Damage:

• Scratches not exposing base material: Generally acceptable all classes
• Chips exposing base material: May be acceptable Class 1/2, defect Class 3
• Cracks: Defect all classes if structural or affecting function

Lead/Termination Damage:

• Scratches: Acceptable if plating intact
• Nicks reducing cross-section >10%: Defect all classes
• Bent leads: May require straightening, criteria vary by component type

Cleanliness and Residue Criteria

Cleanliness requirements depend on whether the assembly will be conformally coated and the type of flux used.

General Cleanliness Requirements:

• No flux residue that would impede visual inspection
• No particulate matter that could cause electrical issues
• No corrosive residue
• White residue from no-clean flux: Generally acceptable if non-corrosive

For Class 3 assemblies, cleanliness testing (ionic contamination, ROSE test) is typically required in addition to visual inspection.

IPC-A-610 vs J-STD-001: Understanding the Difference

One of the most common questions in electronics manufacturing is: “What’s the difference between IPC-A-610 and J-STD-001?” They’re companion standards that work together, not alternatives.

The Key Distinction

J-STD-001 defines how to build the assembly—materials, methods, and process requirements.

IPC-A-610 defines how to inspect the finished assembly—acceptance criteria for the completed product.

Comparison Table: IPC-A-610 vs J-STD-001

Aspect	IPC-A-610	J-STD-001
Full Title	Acceptability of Electronic Assemblies	Requirements for Soldered Electrical and Electronic Assemblies
Focus	End product inspection	Manufacturing process
Content Type	Visual acceptance criteria with photos	Process requirements and procedures
Primary Users	Inspectors, QC engineers	Process engineers, assemblers
Covers Processes	No	Yes (temperatures, materials, methods)
Covers Environment	No	Yes (ESD, humidity, lighting)
Hands-On Training	Optional (theory only)	Required (practical soldering)
Includes	What the product should look like	How to make the product correctly

When to Use Each Standard

Use J-STD-001 when:

• Setting up assembly processes
• Training soldering operators
• Specifying materials and methods
• Defining process controls
• Troubleshooting manufacturing issues

Use IPC-A-610 when:

• Performing incoming inspection
• Conducting in-process inspection
• Final product acceptance
• Resolving accept/reject disputes
• Training inspection personnel

How They Work Together

J-STD-001 tells your assemblers how to solder correctly. IPC-A-610 tells your inspectors how to evaluate the results. A well-run operation uses both: J-STD-001 to prevent defects through proper process control, and IPC-A-610 to verify the process is producing acceptable results.

If you’re only going to implement one standard, most companies choose IPC-A-610 because it directly addresses the accept/reject decisions that occur daily. However, for complete quality coverage, both standards should be part of your quality system.

IPC-A-610 Certification and Training

IPC offers a structured certification program for IPC-A-610 that validates understanding and application of the standard.

Certification Levels

Level	Title	Duration	Purpose
CIS	Certified IPC Specialist	2-3 days	Operators, inspectors, technicians
CSE	Certified Standards Expert	Additional training	Advanced knowledge, conflict resolution
CIT	Certified IPC Trainer	4-5 days	Train and certify CIS candidates

CIS (Certified IPC Specialist) The most common certification level. CIS certification demonstrates working knowledge of IPC-A-610 and ability to apply acceptance criteria correctly. Suitable for assembly operators, inspectors, quality technicians, and engineers.

CSE (Certified Standards Expert) Advanced certification for personnel who need deeper understanding of the standard. CSEs are qualified to resolve accept/reject disputes and provide technical guidance on IPC-A-610 interpretation.

CIT (Certified IPC Trainer) The highest level. CITs can train and certify CIS candidates within their organization. This requires demonstrating both technical expertise and training ability. Having an in-house CIT allows companies to train their own personnel without relying on external training providers.

Certification Requirements

To become CIS certified:

• Attend training from a CIT or approved training center
• Pass open-book written exams for each module (minimum 70% score)
• No prerequisite certifications required

To become CIT certified:

• Prior CIS certification recommended
• Attend CIT training (4-5 days)
• Pass both open-book and closed-book exams (minimum 80% score)
• Demonstrate ability to deliver training effectively

Recertification

All IPC certifications are valid for two years. Recertification requires:

• Updated training on current revision (if changed)
• Passing current exams
• Completed within 90-day grace period after expiration

Training Costs and Providers

CIS training typically costs $800-1,500 per person depending on provider and location. CIT training ranges from $2,500-4,000 including materials.

Authorized Training Providers:

• EPTAC Corporation
• BEST Inc.
• STI Electronics
• Blackfox Training Institute
• IPC regional training centers worldwide

Implementing IPC-A-610 in Your Facility

Adopting IPC-A-610 requires more than buying the standard and telling inspectors to use it. Effective implementation involves training, documentation, and process integration.

Step 1: Determine Your Class Requirements

Work with customers and engineering to determine the appropriate class for each product. Document class requirements in work orders, travelers, or quality plans.

Step 2: Train Personnel

At minimum, train all inspection personnel. Consider training assembly operators as well—inspectors catch defects, but trained operators prevent them.

Recommended training levels:

• Inspectors: CIS certification
• Quality engineers: CIS or CSE certification
• Production supervisors: CIS certification or awareness training
• Assembly operators: Awareness training on key criteria

Step 3: Establish Inspection Procedures

Create work instructions that reference IPC-A-610 for specific criteria. Include:

• Inspection equipment requirements (magnification, lighting)
• Sampling plans (100% inspection vs. AQL-based)
• Documentation requirements
• Accept/reject authority
• Nonconformance handling

Step 4: Provide Proper Equipment

IPC-A-610 inspection requires appropriate tools:

Equipment	Purpose	Typical Specification
Magnification	Visual inspection	1.5X-10X depending on feature size
Lighting	Illuminate inspection area	500-1000 lux minimum
Reference standard	Accept/reject criteria	Current IPC-A-610 revision
ESD protection	Prevent damage	Per ANSI/ESD S20.20

Step 5: Integrate with Quality System

Link IPC-A-610 to your broader quality management system:

• Reference in quality manual
• Include in process control plans
• Use as basis for supplier quality requirements
• Include in customer quality agreements

What’s New in IPC-A-610J (2024)

The 2024 revision includes several significant changes from Revision H:

Major Changes:

• Participation from 31 countries (expanded from 29)
• New surface mount component types added
• Updated graphics and illustrations
• Clarified criteria for several conditions
• Continued removal of target conditions (started in Rev H)

Removed Content: Target conditions were eliminated in Rev H and remain absent in Rev J. The rationale: target conditions created confusion because inspectors sometimes rejected acceptable conditions that didn’t match the target. Now criteria are simply Acceptable, Process Indicator, or Defect.

Updated Criteria: Several specific criteria were refined for clarity, particularly around newer component packages (QFN, LGA, press-fit connectors) and mixed technology assemblies.

IPC-A-610 Resources and Downloads

Where to Purchase the Standard

• IPC Official Store: shop.ipc.org/ipc-a-610 (PDF or hardcopy)
• ANSI Webstore: webstore.ansi.org
• Document Center: document-center.com

Prices range from approximately $200-400 depending on format and membership status. IPC members receive discounts.

Related IPC Standards

Standard	Title	Relationship to IPC-A-610
J-STD-001	Requirements for Soldered Electrical and Electronic Assemblies	Process requirements (companion to A-610)
IPC-A-600	Acceptability of Printed Boards	Bare board acceptance (prerequisite)
IPC-A-620	Requirements and Acceptance for Cable and Wire Harness Assemblies	Wire/cable assemblies
IPC-7711/7721	Rework, Modification and Repair of Electronic Assemblies	Rework procedures
IPC-6012	Qualification and Performance Specification for Rigid Printed Boards	Board fabrication

Free IPC Resources

• IPC.org — Standards information, training provider directory
• IPC EDGE — Online learning platform
• IPC Validation Services — Testing and certification programs

Training Provider Contacts

• EPTAC: eptac.com — 800-643-7822
• BEST Inc.: solder.net — 847-797-9250
• STI Electronics: stiusa.com — 256-461-9191
• Blackfox: blackfox.com — 888-837-9959

Frequently Asked Questions About IPC-A-610

Is IPC-A-610 certification required by law?

No, IPC-A-610 certification is not legally required. However, many customers—especially in aerospace, defense, and medical industries—require suppliers to have IPC-A-610 certified personnel. Government contracts often specify IPC standards. Even without external requirements, certification provides credibility and ensures consistent inspection practices.

How often does IPC-A-610 get updated?

IPC typically revises major standards every 3-5 years. The revision cycle for IPC-A-610 has been: Rev G (2017), Rev H (2020), Rev J (2024). Each revision incorporates industry feedback, addresses new technologies, and clarifies ambiguous criteria. When a new revision releases, certified personnel should update their training within a reasonable timeframe, typically at their next recertification.

Can I use IPC-A-610 for wire harness inspection?

No, IPC-A-610 is specifically for electronic assemblies (PCBAs). For wire and cable harness assemblies, use IPC/WHMA-A-620, which provides acceptance criteria tailored to wire harness construction including crimping, wire routing, and connector assembly. Some overlap exists where wires terminate to PCBs, but dedicated harness inspection should reference A-620.

What’s the difference between a “process indicator” and a “defect”?

A process indicator is a condition that doesn’t affect product function or reliability but indicates the process could be improved. It’s acceptable but suggests the manufacturing process isn’t optimized. A defect is a condition that fails to meet acceptance criteria and requires disposition—either rework, use-as-is with customer approval, or scrap. Process indicators don’t require action; defects do.

If my customer doesn’t specify a class, which should I use?

When no class is specified contractually, Class 2 is the industry default for commercial and industrial electronics. This provides reasonable workmanship standards without the cost premium of Class 3. However, document this assumption and communicate it to your customer. Some companies establish Class 2 as their standard and require explicit customer authorization for Class 1 (to avoid quality complaints) or Class 3 (to address cost implications).

Conclusion

IPC-A-610 is the foundation of electronics assembly quality inspection. It transforms subjective quality judgments into objective, documented criteria that everyone in the supply chain can understand and apply consistently. Whether you’re inspecting boards on a production line or evaluating suppliers halfway around the world, IPC-A-610 provides the common language that makes quality discussions productive.

The three-class system allows appropriate quality levels for different applications—rigorous enough for aerospace, practical enough for consumer products. The illustrated criteria remove ambiguity. The certification program ensures inspectors apply criteria consistently.

If you’re responsible for electronics quality and haven’t yet implemented IPC-A-610, start now. Train your inspectors. Document your class requirements. Use the standard as your reference for accept/reject decisions. The investment in training and standards pays back through reduced disputes, consistent quality, and customer confidence.

For those already using IPC-A-610, ensure you’re working with the current J revision and that your certified personnel maintain their certifications. The standard evolves, and staying current ensures your quality practices reflect industry best practices.

Quality isn’t an accident. It’s the result of clear standards, trained people, and disciplined execution. IPC-A-610 provides the standards—the rest is up to you.