Electronics inspection uses automated optical inspection (AOI) and solder paste inspection (SPI) to check printed circuit boards at each stage of assembly: paste deposits, component placement, polarity and solder joints. Faults are found while a board can still be reworked cheaply.
Automated optical inspection (AOI) images an assembled circuit board and compares every component and joint with what the design and workmanship standard require. Solder paste inspection (SPI) does the same for the paste deposits before components are placed, usually in 3D.
Inspection at several points in the line matters because most solder defects start with the paste. Catching a bad print before placement costs almost nothing; finding the same fault in a finished product costs a great deal.
Solder paste inspection measures the volume, area, height and position of every deposit after printing.
Pre-reflow AOI confirms parts are present, correct and aligned before soldering fixes any mistake in place.
Post-reflow AOI checks solder joints, bridges, polarity and tombstoning with multi-angle lighting.
An operator reviews flagged locations on screen and sends real defects to rework.
Defect data is linked back to the printer, placement machine or oven so the cause is corrected.
Measures paste height and volume, not just area, which is the strongest early predictor of solder joint quality.
Coloured light from several angles reveals the shape of solder fillets, so joint quality can be judged from the image.
Reads component markings and checks polarity marks so reversed or wrong-value parts are caught.
Conformal coatings with a UV tracer glow under UV light, so coverage and keep-out areas can be checked.
Two example project scopes showing how the station, the checks and the outputs are defined. Every plant is different, so the final configuration is confirmed after a feasibility study on your own parts.
The situation: An electronics assembler inspects boards under a magnifier after reflow and misses intermittent faults.
The situation: A controls manufacturer ships assembled units and receives returns for missing connectors.
Industrial cameras, lenses, line-scan cameras and code readers are available through our machine vision catalog, quoted with delivery to Sri Lanka. We select the hardware for your application during the feasibility study.
Browse the hardware catalogEvery product, surface and line behaves differently under a camera, so every project starts with evidence from your own material.
A site visit to understand your product, line speed, quality criteria and where the check should sit.
We image your good and defective samples and show what the system can reliably detect. This is the go or no-go.
One station on one line, running beside your inspectors until results match and your team trusts them.
More lines, integration with your PLC and systems, and local support from our Sri Lankan engineering team.
Vision error-proofing (poka-yoke) for assembly lines: confirm every component is present, correct, oriented and seated, count parts, and keep an image record of each assembly for traceability.
Non-contact measurement of lengths, diameters, hole positions, gaps and profiles with telecentric optics and 3D laser profiling. Measure every part in-line, pass or fail it against tolerance, and log data for SPC.
Sort fabric rolls, cut panels and washed garments into buyer shade bands with CIELAB measurement and 555 codes.
Every machine vision application we design and build, in one place.
SPI inspects solder paste after printing and before components are placed, usually measuring in 3D. AOI inspects components and solder joints, before reflow for placement and after reflow for soldering.
IPC-A-610 is the widely used industry standard for the acceptability of electronic assemblies. It defines what acceptable and defective solder joints and component placements look like, in three product classes with increasing requirements.
Post-reflow AOI is the most common starting point. Adding SPI after the printer catches the cause of most solder defects earlier. The right combination depends on board complexity and volume.
Yes. Through-hole components and wave or selective solder joints can be inspected, usually from the solder side, with lighting chosen for through-hole fillets.
No. AOI finds visible defects quickly and cheaply; in-circuit and functional tests check electrical behaviour. Used together, they give much better coverage than either alone.
Tell us what you need to check and share some good and faulty samples. We will show you what a camera can reliably see before you commit to anything.
Photographs show representative plants and equipment, not Cerox installations or client sites. Diagrams by Cerox Engineering. Photo credits, via Wikimedia Commons: SMT placement line by Megger Ltd., CC BY 3.0; Populated circuit board by Loozrboy, CC BY-SA 2.0; Inspection camera in a placement machine by Nelatan, CC BY-SA 3.0.