PCBA AOI detection

AOI Inspection Service

FS Technology cannot tolerate any slight errors in the PCBA manufacturing process, whether in production or after delivery. The failure of any link will lead to the increase of delivery time and manufacturing cost, which will damage the brand image of FS Technology and reduce the trust of customers in us. In order to avoid these negative effects, FS Technology not only formulates a strict quality management system, but also provides a wide range of PCB testing services. AOI automatic optical inspection is one of the links in all inspection processes. The picture below shows two advanced AOI inspection machines used by FS Technology to test the quality of SMT assembly.

aoi machine for pcb
EKT-VT-680D Vision Inspection AOI Automatic Optical Equipment
SONY automatic optical inspection equipment

What is AOI testing?

A technique for checking printed circuit boards (PCBs) and other electronic components for flaws or faults are called PCB AOI testing. Cameras and image processing tools are used in this kind of circuit board test to swiftly find inconsistencies in production quality. AOI PCB assembly inspection consists of three steps:

  • Take pictures of the surface-mounted components(SMD) on the surface of PCBA
  • Compare pictures to a set of predefined criteria
  • Report any discrepancies that do not meet specified criteria for additional evaluation

Advantages of 3D AOI inspection

AOI testing PCB capability is one of the measures used to test the strength of PCBA assembly companies. At present, most assembly companies in the industry use 2D PCB AOI equipment, but these low-level equipments have certain limitations in testing, such as insufficient information on the part of printing glue and soldering, and misjudgments often occur during testing. In order to solve this shortcoming, FS Technology introduces advanced 3d AOI inspection machines to ensure inspection quality. Below we will summarize the advantages of FS Technology in AOI detection:

  • AOI testing as an adaptive in-process test can save project costs, because if problems are found, the manufacturing or assembly settings can be adjusted immediately, so that subsequent products will not have these common PCB problems.
  • Modern electronic assembly and inspection procedures use AOI optical inspection as a key tool. It is quicker than manual inspections, produces more precise results, and removes the possibility of human error brought on by exhaustion or a lack of focus.
  • Additionally, it can swiftly and accurately spot any kind of mistake, including missing SMD components, solder voids, misshaped connectors, and wrong PCB component orientation.
  • The AOI test’s methodology is very helpful in making sure that the goods are safe and up to par before being delivered to clients. 
  • 3D AOI automatic optical inspection machine can detect more complete PCBA information, and reduce the work intensity of PCB engineers with a more operable programming method.
  • Accurately detect the floating of PCBA component pins that cannot be detected by 2D equipment, and improve the yield rate.
  • Overall, AOI inspection PCB is a crucial tool for any facility that assembles electronic components since it ensures high-quality products with little expense or effort.

When does the AOI inspection equipment work?

Continuous AOI testing can be carried out throughout production runs to guarantee quality control throughout the production phase. This enhances product dependability and lowers the cost of rework or errors that are passed on to customers. In AOI automated optical inspection, bare PCBs and PCBAs both operate flawlessly. Flaws like shorts, opens, and improper solder are evaluated during PCB manufacturing inspection. PCB Assembly examination looks for issues with component soldering, polarity, and values.  According to customers’ needs and their cost affordability, FS Technology installs AOI anywhere in the manufacturing line. In order to enhance inspection efficiency and save associated expenses, it is best to place the AOI circuit inspection after reflow soldering because the majority of faults are the result of nonconformance occurring during the soldering process. 

The Necessity of Automated Optical Inspection

Manual inspection with a magnifying glass

Although the PCBA industry has made progress in recent years, whether it is manufacturing, assembly or testing technology, better production capacity means that the circuit structure is more complex. We can clearly realize that with the development of surface mount technology, the size of the electronic PCBA board we use is getting smaller and smaller, and the electronic equipment is getting more and more sophisticated.

Due to the increasing complexity of circuit boards, manual PCBA inspection is no longer a sensible option. The majority of issues are located in the thousands of soldered joints that are present on even boards that are considered to be typical. Although manual inspection can occur in any link of the PCB assembly and manufacturing process and is instant, the efficiency of this inspection solution is not high. Even the most professional inspectors can become fatigued and improperly applied due to the high density of solder fillets. Facts have proved that this detection method is not reliable, and doing it for cost saving will lead to circuit board failure, causing more losses. Therefore, AOI solder fillet inspection will completely replace manual work, and manual inspection will become an auxiliary inspection solution. The picture below shows the high-density PCBA products tested by AOI automation equipment.

Given the market’s current demand for high volume, high quality products to be introduced to customers very quickly, techniques that are reliable and effective are necessary to ensure that product quality remains high. Automatic optical inspection(AOI), is a crucial component of an integrated electronics test strategy that guarantees costs are kept as low as possible by identifying issues early in the production process. The adoption of automated or automatic optical inspection tools is one remedy for this. Just after the soldering process, automated optical inspection devices can be added to the production line. They can be used in this way to identify issues early in the production process. This is undoubtedly the best area to uncover flaws because they are more expensive to correct the further along in the production process they are discovered. Additionally, early manufacturing difficulties in the solder and assembly areas can be identified, and the information is then used to provide prompt feedback to earlier stages. In this method, a prompt reaction can guarantee that issues are immediately identified and fixed before an excessive number of boards are created with the same issue.

How Automatic Optical Inspection System Works

Any non-compliant discrepancies in the automatic optical inspection system are flagged for further investigation. PCBA manufacturers can guarantee quality control during production runs and prevent expensive reworks or errors from being passed on to customers by measuring performance against a pre-defined set of criteria. AOI is a crucial tool in identifying faults before they affect customers because it also reduces human error brought on by fatigue or a lack of concentration. Before any items leave the assembly line, the AOI test’s operating principle ensures that product dependability and safety standards are met.

PCBA manufacturers can enhance their manufacturing processes while cutting expenses related to rework or recall campaigns by investing in automated optical inspection equipment. The AOI test’s working theory enables producers to quickly and reliably identify all types of faults and take appropriate action. AOI testing ensures quality control during production runs because it is quicker than manual inspections. Any firm seeking to generate high-quality products quickly and affordably must include an automated optical inspection system into their electronic assembly line.

Overall, the AOI test’s operating concept gives manufacturers a reliable and efficient way to rapidly and properly inspect components, while also enhancing manufacturing procedures and lowering the need for rework or recall campaigns.

FS Tech's AOI inspection better serves PCBA projects

It is the best way to gain understanding and influence our recommendations for your solutions. Because of our combined knowledge, we can provide you with PCBA guidance that is of the same high level and reliability. AOI test PCB can be used to discover a range of surface problems, including scratches, nodules, stains, openings, and shorts, too much or too little solder, incorrect or missing components, inappropriate component polarity, etc., according to visual techniques. Since AOI inspection can perform these tasks quickly and precisely, these defects are essentially parts of manual visual inspection that were regularly utilized before it became widely used.

Post-reflow When inspecting solder joint faults such bridges, fractured joints, dry joints, etc., AOI is less expensive than Automated X-ray Inspection (AXI).

To sum up, AOI manufacturing is a technology that integrates optics, mechanics, electrical control, and software to replace the human eye. PCBs are becoming smaller and more sophisticated in the real world; even a very simple board may include literally thousands of soldered components. To succeed in today’s competitive PCBA production environment, AOI continuously evaluating SMT and DIP assembly production quality and making necessary corrections to the process flow. A cheaper cost of production, reduced waste, and increased yields are all benefits of investing in AOI systems. 

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