IPC-A-610: acceptability of electronic assemblies
IPC-A-610 is the IPC standard that defines visual acceptance criteria for electronic assemblies. It describes what acceptable and defective solder joints, component placement, cleanliness and damage look like on a populated PCB, using photographs and illustrations, across three product classes. It is the most widely used inspection standard in PCB assembly.
IPC-A-610 explained
IPC-A-610, Acceptability of Electronic Assemblies, is used by assembly manufacturers, inspectors and customers as a common reference for judging the finished assembly. It is a post-assembly acceptance document: it shows what the result should look like, rather than prescribing how to solder.
The standard covers a wide range of topics, including surface-mount and through-hole solder joints, component mounting and orientation, wire and terminal connections, hardware installation, marking, cleanliness, conformal coating, and damage to components and laminate. For many conditions it describes three levels: target (close to perfect), acceptable (may not be perfect but maintains integrity and reliability) and defect (insufficient to ensure form, fit and function). It also notes process indicators — conditions that are not defects but suggest the process should be looked at.
Like other IPC standards, IPC-A-610 uses three product classes. Class 1 covers general electronic products. Class 2 covers dedicated-service electronic products, where extended life and uninterrupted service are desired but not critical. Class 3 covers high-performance or harsh-environment products where downtime cannot be tolerated. The criteria get stricter from Class 1 to Class 3.
IPC-A-610 is revised periodically, with each revision identified by a letter. Customers usually reference the current revision and the class on their purchase order or drawing. The standard is closely related to J-STD-001, which sets the requirements for soldered electrical and electronic assemblies, and to IPC-A-600, which covers bare boards. Inspectors are often trained and certified through IPC's training programmes.
When IPC-A-610 matters
IPC-A-610 matters whenever you need an agreed definition of a good assembly. Without a stated standard and class, the assembler applies its own default, which is usually Class 2. That is fine for most commercial products, but a mismatch between expectations and the delivered workmanship is a common source of disputes.
Specify the class early. Class 3 has stricter criteria for things such as solder fill in plated through-holes, heel fillets and component placement offsets, which can influence both the design and the assembly process. A board designed without Class 3 in mind may be difficult to assemble to Class 3.
IPC-A-610 is a visual standard. It does not replace electrical testing, X-ray inspection of hidden joints or reliability testing; hidden joints such as BGA balls require X-ray to evaluate. Also note that the acceptance criteria apply to the assembly, so the bare board should be ordered to a matching IPC-6012 class.
IPC-A-610 vs IPC-A-600 vs J-STD-001
IPC-A-600 is used to inspect the bare board before assembly, while IPC-A-610 is used to inspect the board after components are fitted. J-STD-001 specifies how soldered assemblies must be made — materials, processes and requirements — whereas IPC-A-610 is the inspection reference for the result. Many customers reference J-STD-001 for process requirements and IPC-A-610 for acceptance, at the same class.
IPC-A-610 in your quote request
In your quote request, state the IPC-A-610 class you require and, if relevant, the revision. If you also have process requirements, reference J-STD-001 at the same class, and specify the IPC-6012 class for the bare boards so they match. Note any inspection requirements beyond visual inspection, such as X-ray for BGAs or first-article inspection reports. If you are unsure which class fits your product, describe the application.
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PCB assembly →FAQ about IPC-A-610
What is the IPC-A-610 standard?
IPC-A-610 is the acceptability standard for electronic assemblies. It defines, with photographs and illustrations, what acceptable and defective solder joints, component placement, cleanliness and damage look like on a populated PCB. It uses three classes with increasingly strict criteria and is the most widely used reference for inspecting assembled boards.
What is the difference between IPC-A-610 and IPC-A-620?
IPC-A-610 covers the acceptability of electronic assemblies, meaning populated printed circuit boards. IPC/WHMA-A-620 covers cable and wire harness assemblies, including crimps, wire terminations, splices and harness construction. A product with both a PCBA and cable assemblies often references both standards, each for its own part of the build.
What is the difference between IPC-A-610 Class 2 and Class 3?
Class 2 is for dedicated-service electronics, where long life is desired but occasional failure is not critical. Class 3 is for high-reliability products where downtime cannot be tolerated. Class 3 sets stricter criteria for solder fillets, through-hole fill, placement offsets and visible defects, so more conditions are rejected and inspection effort increases.
Related terms
- IPC-A-600
IPC-A-600 is the IPC standard that defines visual acceptance criteria for bare printed circuit boards. It specifies what surface, dimensional, and structural conditions are acceptable across three class levels, and is the reference document fabricators use to inspect boards before shipment.
- IPC class 2 vs class 3
IPC class 2 and class 3 are two acceptance levels defined in IPC standards (A-600 for bare boards, A-610 for assemblies). Class 2 covers dedicated-service electronics; class 3 covers high-reliability electronics where failure cannot be tolerated. Class 3 demands tighter tolerances, stricter inspection, and typically costs more.
- AOI
AOI (Automated Optical Inspection) uses high-resolution cameras to inspect solder joints, component placement, and orientation after assembly. Modern 3D AOI measures joint height and volume volumetrically, catching defects like lifted leads and insufficient solder that 2D systems miss. Limited to visible surfaces — hidden joints under BGAs require X-ray inspection.
- X-ray inspection
X-ray inspection is a non-destructive testing method that penetrates the PCB to reveal hidden solder joints under BGAs, QFNs, and other bottom-terminated packages. It detects voids, head-in-pillow defects, bridging, and missing joints that AOI cannot see. Available in 2D (top-down) and 3D CT (full volumetric) variants.
- PCBA
PCBA (Printed Circuit Board Assembly) is the process of populating a bare PCB with electronic components — resistors, capacitors, ICs, connectors, and other parts — to produce a functional electronic assembly ready for testing or integration into a finished product.