When commissioning a printed circuit board assembly (PCBA), one of the most important decisions you make is which quality standard to specify. Get it right and your product ships on time, performs reliably in the field, and satisfies your regulatory obligations. Get it wrong, and you face field returns, costly rework, compliance failures, or a product that costs far more to build than the application warranted.
IPC-A-610, the globally recognised standard for the acceptability of electronic assemblies, provides a shared framework for answering this question. It’s used by EMS providers, OEMs, procurement teams, and quality managers worldwide to define what 'good' looks like, from solder joint geometry to component placement tolerances to cleanliness requirements.
This guide explains the three IPC-A-610 classes, compares them across the dimensions that matter most to OEMs, and provides a practical decision framework for selecting the right class for your product.
What is IPC-A-610?
IPC-A-610, formally titled 'Acceptability of Electronic Assemblies', is published by the IPC (Association Connecting Electronics Industries). It is the most widely used acceptance standard in the electronics manufacturing industry, covering visual inspection criteria, workmanship standards, and quality assurance requirements for finished PCBAs.
Divided into three classes—Class 1, Class 2, and Class 3—the standard spans solder joint quality, component placement and orientation, cleanliness, conformal coating, mechanical integrity, and marking. It is used on production lines by inspectors, quality engineers, and EMS providers as the objective reference for accepting or rejecting a finished assembly.
IPC-A-610 works in conjunction with related standards, including J-STD-001 (soldering requirements), IPC-A-600 (PCB acceptability), and IPC-6012 (rigid PCB qualification). Together, these form a comprehensive quality framework for the full manufacturing process.
What is IPC-A-610J? (2024 revision)
IPC-A-610J is the current revision of the standard, released in April 2024. Key updates in this revision include:
- New and enhanced guidance on conformal coating inspection, including clarified criteria for voiding and bubble assessment
- Substantially expanded visual reference imagery to improve inspection consistency across facilities and geographies
- Updated solder joint evaluation guidelines
- Revised cleanliness standards to address modern flux residue chemistry
- Recommendations for enhanced inspector training programmes
When specifying IPC-A-610 on a purchase order or RFQ, always state the revision explicitly; for example, 'IPC-A-610J Class 3'. Acceptance criteria can differ between revisions, and you should confirm which version your EMS partner is certified to.
The three classes of IPC-A-610
The standard organises electronic assemblies into three performance classes based on the consequences of failure and the reliability demands of the end application.
Class 1: General electronic products
Class 1 applies to assemblies where the primary requirement is functionality, and where cosmetic imperfections or minor workmanship variations are acceptable, provided the product operates as intended. Typical examples include consumer toys, simple household appliances, and short-lifecycle disposable electronics.
For Class 1 products, cost-effectiveness is usually the dominant driver. Visual appearance and long-term reliability are secondary. The standard is the most lenient of the three classes and allows the widest range of workmanship conditions.
Class 2: Dedicated service electronic products
Class 2 covers assemblies that require an extended, reliable service life in normal operating environments, where failure is undesirable but not catastrophic. This is the most widely specified class in commercial and industrial electronics manufacturing.
Typical Class 2 applications include:
- Industrial control systems and automation equipment
- Telecommunications infrastructure
- Commercial computing hardware
- Automotive electronics (non-safety-critical)
- Instrumentation and measurement equipment
Class 2 tolerates limited cosmetic imperfections, for example, a surface-mount component that is slightly offset from its pad but maintains full electrical and mechanical connection. These conditions are acceptable under Class 2 because they do not affect performance or reliability in standard operating environments.
The class strikes a practical balance between quality assurance and manufacturing throughput, making it the default choice for most PCBA programmes.
Class 3: High-performance electronic products
Class 3 is the most stringent classification, reserved for assemblies where failure could result in severe consequences like loss of life, serious injury, mission failure, or system-level catastrophe. There is zero tolerance for workmanship defects that might pass under Class 2.
Typical Class 3 applications include:
- Medical devices — implantables, life-support systems, surgical equipment
- Aerospace and avionics systems
- Defence and military electronics
- Safety-critical industrial and automotive systems
To achieve Class 3, every aspect of production must meet the IPC-A-610J acceptance criteria: laminate selection, plating thickness, solder joint geometry, cleanliness, conformal coating, and inspection processes.
This typically requires slower SMT placement speeds, more frequent verification steps, and tighter process controls, all of which contribute to higher unit cost and longer lead times.
ICP Performance Classes for PCB
| IPC Class 1 | IPC Class 2 | IPC Class 3 | |
| Category | General electronics | Dedicated service electronics | High-reliability electronics |
| Lifecycle | Short (1-3 years) | Moderate to long (3-10 years) | Very long (10+ years) |
| Quality | Cost-effective | Reliable | Highly reliable |
| Examples | Disposable electronics, basic IoT devices | Smart home appliances, some industrial equipment, EV charging systems | Aerospace, autonomous systems, medical devices, safety-critical e-mobility applications |
| Cost implications | Low | Moderate | High |
| Reliability requirements | Basic functionality | Extended reliability | Mission-critical reliability |
| Manufacturing complexity | Low | Medium | High |
| Typical testing | Basic functional testing | ICT and functional environmental stress screening | Extensive reliability testing, X-ray inspection, environmental stress testing |
How to choose the right IPC-A-610 Class
Use this decision framework to guide your class selection:
- Could failure of this product cause injury, death, or mission failure? → If YES: Class 3 required.
- Is this product used in a regulated sector with defined quality management requirements (medical, aerospace, defence, automotive safety)? → If YES: Class 3 strongly indicated; verify with your regulatory/quality team.
- Does the product operate continuously in harsh environments (extreme temperatures, vibration, humidity, altitude)? → If YES: consider Class 3, or at minimum a Class 2 programme with enhanced environmental validation.
- Is the product a commercial or industrial device with standard operating conditions, where failure is undesirable but not catastrophic? → If YES: Class 2 is almost certainly appropriate.
- Is the product short-lifecycle, low-cost, and non-critical? → If YES: Class 1 may suffice, but verify with your EMS partner.
When in doubt, the cost of specifying too low a class after a field failure is almost always higher than the upfront cost of specifying Class 3 from the outset.
Industry-specific guidance
Medical devices
The vast majority of medical device PCBAs are specified to Class 3. For implantable devices, life-support systems, and Class II or III medical equipment (under EU MDR / FDA classifications), Class 3 is effectively a baseline quality requirement. IPC-A-610 compliance complements your EMS partner's ISO 13485 quality management system certification.
Aerospace and defence
Aerospace and defence electronics are canonical Class 3 applications. The consequences of field failure — loss of aircraft, mission failure, personnel risk — make zero-defect workmanship a non-negotiable baseline. Relevant complementary frameworks include AS9100 (aerospace quality management) and ITAR/EAR requirements, where applicable.
Industrial electronics
Industrial control systems, power electronics, and automation equipment typically operate to Class 2. However, safety-critical industrial applications, such as machine safety controllers or process control systems in hazardous environments, may require Class 3 workmanship. Confirm with your functional safety team if IEC 61508 or similar standards apply.
Transportation
Transportation electronics span both classes. Infotainment systems, comfort electronics, and non-safety systems typically operate to Class 2. Powertrain, ADAS, braking, and steering systems require Class 3 due to safety implications. IATF 16949 quality management is standard in the automotive supply chain and complements IPC-A-610 compliance.
The practical considerations of specifying IPC-A-610
- Design for Manufacturability (DFM): Your class selection should inform — and be informed by — your design choices. Class 3 assemblies require tighter component pitch tolerances, pad geometry optimised for high-integrity solder joints, and careful consideration of through-hole barrel dimensions.
- Documentation: Specify the IPC-A-610 revision and class on every RFQ, purchase order, and assembly drawing. Attach any supplemental workmanship documents or customer-specific criteria. Ambiguity at the quoting stage leads to disputes at inspection.
- Supplier communication: Confirm that your EMS partner's IPC certification covers the class and revision you need. Ask specifically which revision they are trained and certified to, and whether their in-house trainers hold CIT (Certified IPC Trainer) status. IPC certification requires renewal every two years — ask for evidence of current validity.
Cost vs quality: The risks of over- and under-specifying
Applying Class 3 to a Class 2 product adds unnecessary cost without a corresponding reliability benefit. If your operating environment does not demand Class 3 workmanship, your overspecification is paying for inspection rigour that your product's end use does not require.
Likewise, applying Class 2 to a product that should be Class 3 creates reliability risks, potential regulatory noncompliance, and the far greater costs of field failures, recalls, and liability. In regulated sectors, under-specifying can also invalidate your product certification.
The right answer is the class that matches your product's criticality, operating environment, and regulatory context — no more, no less.
Working with your EMS partner
A well-established EMS partner should do more than simply meet the IPC class you specify at final inspection. The best providers apply IPC-A-610 criteria throughout the production process, from incoming component inspection to solder paste deposition, SMT placement, reflow profiling, and post-assembly cleaning, not just at the end of the line.
Look for:
- In-house IPC Trainers (CIT-certified) who can train and re-certify your inspection team
- IPC Certified Interconnect Specialists (CIS) on the production floor
- Documented process controls aligned to the specified class
- Willingness to work to customer-specific workmanship supplements where required
- Regular IPC certification renewal (every two years) and evidence on request
In some cases, OEMs choose to supplement IPC-A-610 with their own workmanship criteria — either to raise the standard in specific areas or to address product-specific requirements not covered by the standard. If you do this, communicate your criteria clearly and early, and reference them on every RFQ and purchase order.
Choosing the right IPC-A-610 class is one of the first conversations we have with every new customer. If you are unsure which class your product requires, or if you want to discuss how ESCATEC's IPC-certified processes can support your programme, our PCBA experts are ready to help. 
FAQs
1. What is IPC-A-610 and what does it cover?
IPC-A-610, titled 'Acceptability of Electronic Assemblies', is the globally recognised standard developed by IPC that defines visual inspection criteria, workmanship standards, and acceptance requirements for PCBAs. It covers solder joints, component placement, cleanliness, conformal coating, and mechanical integrity, and is used by EMS providers and OEMs worldwide to agree on what constitutes an acceptable assembly.
2. Does Class 3 significantly increase manufacturing cost?
Typically yes. Class 3 typically adds 15–30% or more to unit cost through slower SMT speeds, higher inspection overhead, increased scrap rates, and more extensive testing. This premium is almost always justified where product failure creates safety, regulatory, or mission risk.
3. What changed in IPC-A-610J (2024)?
IPC-A-610J introduced enhanced guidance for conformal coating inspection, expanded visual reference imagery, updated solder joint and cleanliness criteria, and training recommendations.
4. Can an EMS partner manufacture to both Class 2 and Class 3?
Yes. Most established EMS providers hold certification across both classes and apply the appropriate standard on a product-by-product basis. Ask specifically for evidence of current certification for the revision and class you require.
Editor’s note: this post was originally published in April 2019, and updated in May 2026 for relevance and accuracy.
