How Are PCB Assemblies Inspected - Miracle Electronics

PCBs are one of the most important constituents of every electronic application, which is why it is important that these elements are error-free. One fault in this part means failure of the entire application. This is why you must always buy standard quality PCBs from a reliable and trustworthy PCB assembly manufacturerfrom Germany. Generally, PCBs are inspected well after construction before being delivered to the customer, so that they are prevented as much as possible from the most common defects. Some of these like opens, shorts, missing electrical components, defective components, wrong component placement, component misalignment, inconsistent soldering, and wrong orientation. Listed below are some of the methods used by manufacturers to inspect their final PCB products. Some manufacturers also inspect their PCB at every stage of manufacturing so that they can identify the defects early enough, rectify them quickly, and minimize product recalls.

Visual inspection

This is one of the most common types of inspection procedures followed for testing a PCB assembly. While the naked eye may miss out on some of the tiny errors, certain kind of special equipment is used to visually inspect a PCB assembly. However, the validity of visual inspection depends on the inspection staff’s capability. The inspectors have to be completely aware of the technical requirement for each type of solder joint. Every solder joint type possibly contains as many as eight kinds of defect standards. Furthermore, visual inspection is applicable only for large defect inspection; it isn't fit for hidden solder joint inspection and other tiny defects.

X-ray Inspection (AXI)

Today, densely populated circuit boards and mini sized PCB assemblies are being manufactured. This makes it very difficult for visual inspection to be carried out. Here, X-ray inspection serves as the best option. With thousands of solder connections, every connection is not visible. This is where X-ray inspection comes in handy. With such kind of inspection, every component, soldering, and misalignment can be checked. In this process, X-rays are directed on the PCB components, which absorb them and produce an image on the other side, which helps identify defects in the wiring assemblies, voids in solder joints, soldering defects, semiconductor packaging, and much more.

Automated Optical Inspection (AOI)

This is a process wherein the circuit board is scanned using a single or multiple video cameras, which click images of the components from various angles. These images are then analyzed by experts to identify defects like scratches, dimensional defects, nodes, stains, incorrect components, and more. Today, with the advancements made, 3D AOI equipment is used to find such tiny faults. Such AOI processes can be employed at various stages of PCB manufacturing.

These are only the most popular inspection methods used. There is a wide range of processes that can be otherwise used like Automatic Laser Test (ALT), X-ray Fluoroscopic System, X-ray Lamination System, and more. So, how do you determine the best PCB assembly inspection method for your particular product? You can leave the choice in the hands of Miracle Electronics, the leading PCB assembly manufacturer from Germany, where not only are the best quality PCB assemblies manufactured, but also, the facility is equipped with test fixture design consisting of lab view functional test fixtures, which is designed for specific PCB assembly testing requirements.

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