Why you need an automated optical pcb inspection of the assembly

Whether turning the pages of the Sherlock Holmes mystery or watching the replay of "Monk", I hope to see these investigators find important details that others cannot. However, even the largest of these detectives finds it difficult to find problems on the assembled printed circuit board. On complex circuit boards, there may be thousands of opportunities for defects, and manual inspection simply cannot reliably search for all defects within a reasonable time.

As part of the different inspection methods that contract manufacturers should use, the Automated Optical PCB Inspection (AOI) system will handle most inspections on the PCBA. The system can quickly assess thousands of details, which are too small for the human eye to capture and report any detected problems to the operator. 

What is AOI PCB assembly inspection and how does it work?

Automated optical inspection equipment has been around for a while, and it is constantly being improved and updated to improve its functionality. This inspection equipment is used in many industries, including PCB manufacturing, for inspecting bare boards, solder paste applications and assembly. For PCB assembly, the AOI system will check component placement and soldering, and will alert inspection technicians of various potential problems, from the use of incorrect parts to bad solder connections.

AOI PCB inspection equipment relies on high-resolution camera systems and different illumination sources such as fluorescence, LED, ultraviolet and infrared to capture image arrays. When assembling a new PCB, the contract manufacturer will run the circuit board through the AOI system after the parts are placed, and then run again after the circuit board is soldered.

In subsequent runs, the AOI system will scan each assembled board and compare these images with the archived images of the gold standard board. When areas that fail to meet the gold standard are found, it will mark these areas as possible defects so that technicians can conduct more detailed inspections.

AOI adjustability: the key to successfully preventing assembly defects

PCB AOI equipment can be "adjusted" according to the needs of the assembled board. The system's adjustability allows contract manufacturers to filter out acceptable problems and capture hard-to-see defects that were difficult to find through visual inspection in the past. The manual inspection process requires technicians to look at every part, marking, and solder joint on the board, which may involve thousands of details in order to check on a complex board. With so many details to check, it is easy to understand the incompleteness. 

On the other hand, the automated optical pcb inspection system enables highly skilled inspectors to focus only on the relatively few potential defects identified by the system. Compared with the labor-intensive manual inspection process, this allows your CM to discover actual defects in a relatively short time.

At Insun, we have a variety of testing and inspection methods that we often use on all production boards including AOI. From the incoming inspection of raw materials and parts to the functional testing of the assembled boards under power, we all ensure that your boards have been assembled and operated as expected. Our goal is to provide you with the best assembled printed circuit board.