Why You Need Automated Optical Inspection for Your PCB Assembly

Printed Circuit Board or ‘PCB’ is crucial to any electronic product, whether it is for consumer use or for industrial purposes. Being the central processing unit for electronics, it is crucial for PCBs to be assembled properly to facilitate effective functioning for electronic products.
As technological innovations continue to grow, PCBs are developed to be smaller, more compact, and more sophisticated to be used to increase the functionalities and streamlining designs of products. This is made possible with the introduction of Surface Mount Technology (SMT).

SMT is a method of mounting electrical components directly onto the surface of the PCB boards. The benefits of using SMTs is the increase in efficiency by automating the manufacturing process to allow for the reduction of costs and improving the quality. Most importantly, SMT allows the average PCB boards to have thousands of soldering joints, whereas it’s through-hole counterpart cannot.

But this comes at a cost.
As components on the PCB become smaller and denser, identifying and repairing defects becomes increasingly more difficult, this is especially true when a defect is only discovered during the final stages of the manufacturing process.
The solution to this is the Automated Optical Inspection (AOI).

What is Automated Optical Inspection?

Automated Optical Inspection as the name suggests, is an automated visual inspection process for the manufacturing of PCBs. This involves cameras that autonomously scans the PCBs for problems such as missing components, short circuits, damaged components, and quality defects. AOI is typically used in the manufacturing process because it is a form of a zero-contact test method, so it won’t interfere with the components on the board.

Advantages of Automated Optical Inspection

  • AOI uses infrared, LED, ultraviolet, and fluorescent illumination to detect problems in real-time during the manufacturing process.
  • AOI is extremely flexible as it can be used throughout any stage of the production process, and it can be carried multiple times if necessary.
  • Identify problems during the early stages of the manufacturing process can drastically reduce costs and time, as opposed to finding out during the final stages of production.
  • As production volumes increase, it can detect surface defects such as missing component, skew, shift, tilts, wrong orientation and co-planarity more efficiently compared to manual inspections which are more susceptible to errors.
  • You can set a standard to which you want the PCBs to match, and the algorithm will test if the PCBs are matching the requirements which you have set for quality assurance, as well as improving the overall manufacturing process speed.

Disadvantages of Automated Optical Inspection

Although AOI comes with many benefits, it also has its limitations:
  • AOI pass rate results are not absolute. Just because a manufactured product has a high pass rate, it does not guarantee the performance of the product itself.
  • In contrast, a low pass rate may not accurately reflect a product’s build quality. The pass rate score can be influenced by the standard in which the EMS provider has set in place. This means that if your EMS provider has set a very high standard for the final product, it can make it more difficult to achieve a high pass rate.
  • It is also important to note that AOI only examines for what it is asked to, this means that if the criteria to be examined are not set properly, it can lead to potential flaws going unnoticed.

Improve Your PCB Assembly Process with Automated Optical Inspection

As we have discussed, AOI can provide many benefits to help streamline the PCB assembly process. As the demand for small and sophisticated boards continue to increase, manual inspections are just not enough to keep up with the demand for high-quality boards that can be produced in high quantities.

AOI will help your business reduce costs in the long-run as it can help detect defects early on in the production process, and it will continue to learn as it identifies more problems, so that it can increase its efficiency of creating high-quality boards without compromising the production speed.

If you are looking for a provider that can produce high-quality boards at high volumes without compromise, we have the solution for you! At ECI Technology, we employ the use of Automated Optical Inspection in our PCBs assembly to provide high-quality and reliable products to meet the need of your business.

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