What Is Automatic Optical Inspection?

With all the latest technological advancements and the need for more robust devices, the need for good quality and top-notch PCBs is rising drastically. Throughout the years, customers have become increasingly used to PCB-integrated smart electronics and smart devices. 

It means the printed circuit boards must be top quality without any production error. There should be zero errors during the production of the PCB. If the PCB does not work properly, it can affect the device’s performance and damage it.

Hence, manufacturers must pass their PCBs via strict methods for checking the PCB’s quality. It helps to identify and eliminate the errors within a PCB.

PCBs are bound to get more complex for future devices. However, it raises the risks as well. Printed Circuit Boards in today’s time are the finest, and the method for checking the quality must be top-notch.

In terms of quality control, there are several inspection methods for PCB. There are several techniques that you can opt for based on your requirements, as well as PCB variants. In this article, we will look at the significance of PCB inspection and how automated optical inspection can help.

Why Optical Inspection Requires Optical Inspection?

During PCB manufacturing, it is essential to inspect the end product. It is for ensuring that everything in the PCB is in its dedicated location. Defective printed circuit boards will cause permanent damage.

The automated optical inspection for the PCB identifies the problems that can be fixed before they are released on the market. Sometimes, the issues within the PCB are not easy to detect, and often, they can be overlooked. If the issues arise in the future, it can affect and hinder the performance of the PCB.

Passing the PCBs via extreme quality control methods will allow you to easily point out unseen and hidden defects. Faulty PCBs are a major concern and affect the reputation of the manufacturer. 

A bad PCB will hinder the reputation of the PCB manufacturer as customers are bound to get disappointed by the lack of quality on their electronic devices. 

Defective PCB can lead to electrical fluctuations and current leakage that can shock the users. The faulty printed circuit board integrated into electronic devices can lead to severe consequences.

Now that you know why PCB inspection is essential before giving the devices to the customers, let us tell you about the techniques for PCB inspections.

Inspection Techniques For PCBs

The PCB inspection can be defined as detecting the possible faults in the PCBs, re-checking the positioning of the PCB parts, and verifying the quality of every part after production.

There are several ways of inspecting the PCBs. Some manufacturing companies use remarkable equipment for quality control. On the other hand, many people use automated testing techniques to inspect the PCB for defects.

However, for less complex and small PCBs, such measures will not be needed. Workers can easily inspect small PCBs for any faults. It is also essential to manual inspection and its significance for different PCB productions.

Manual Visual Inspection

Manual visual inspection is the best method for small and less complicated PCBs. Workers visualize the PCBs themselves or may use a microscope.

The technicians generally double-check the design details of the PCB for the end product as it helps them to confirm whether the end product matches the details.

Workers can inspect the PCBs whenever they want to. There isn’t any rule for the inspection method. However, it is essential to know the factors when inspecting the MVI. Following are the methods that you must keep in mind when performing a manual inspection of your PCB:

• The broadness of the PCB must be accurate.
• The conductive parts of the PCB must be standard.
• The coating quality should be flawless, and you must verify the amounts of placement and flux.
• Ensure that the wirings are properly placed. 
• The pad plating must work at its finest and ensure that there is not any rigidness or roughness.

 Automated Optical Inspection

The manual visual inspection is helpful. However, this method alone does not guarantee that a PCB is in top-notch condition, as there are chances of human errors. However, with the help of automated optical inspection, manufacturers can save themselves from such errors.

The optical inspection process consists of a camera and lights for a 100% quality check of PCBs. These lights aim to easily find the faults in a PCB. Lights across the directions will help to identify the flaws. 

After this, these cameras are used for filming the PCBs while taking images as well to ensure that each part and component is covered. With this, technicians will ensure that the end product is according to the design requirements. 

You can also choose to use the colored lights for optical inspection. Automated optical inspection is amongst the latest methods that is the best alternative to manual visual inspection.

What Is Via Filling?

Every PCB needs vias for them to operate in an efficient environment. Vias are an essential PCB part that provides them with varying features. These vias aim to transfer the signals inside all layers of the PCB.

PCB vias ensures that every layer sends and receives signals without any issues. Optical inspection is essential since these vias are tiny holes filled with copper. 

The copper within the vias leaves no space to provide the best results. However, the copper filling should be controlled because severe fillings can make PCB layers hefty. Additional copper filling can also increase the weight of the PCBs. 

Today, portable and small printed circuit boards are commonly used, and the vias are even smaller. Sometimes, regulating everything in a confined area can be troublesome. However, a good PCB manufacturer can efficiently tackle this task.

Benefits Of Via Filling

PCBs that have via fillings will perform significantly better than those without ones. The PCBs benefit the electronics in several ways. Following are the reasons why PCB vias are essential:

• The PCB components provide greater surface mounting when required.
• The PCB assembly is free from defects. 
• The via-fillings PCBs do not prevent air and liquid from escaping the system.

Copper-plated and Copper-Filled Vias

Copper-plated and copper-filled vias have different uses that are based on the requirements of the users and the type of device PCB is needed for. The following are the benefits of copper-filled vias:

• These vias are essential for enhancing thermal conductivity.
• The heat can easily flow throughout the PCB, which reduces the defect’s chances.
• Copper absorbs a significant amount of heat and leaves sufficient space to keep other components cool when the temperature rises.

Benefits Of Copper-Vias Over Gold-Vias

Different PCB manufacturing companies use resins and gold fillings instead of copper for PCBs. Although you can achieve better results from such fillings, copper offers better output than gold and epoxy resins. Following are some primary reasons why copper vias are better:

• Gold has less thermal conductivity than copper.
• Copper is more affordable than gold.
• Copper fillings are more reliable.
• Copper enhances the longevity of PCBs.
• Smart gadgets and electronics benefit significantly from copper than gold or resin vias.

Conclusion

It is essential and critical to verify the quality of the PCB assembly, and nothing is better than opting for the tried and tested method called automated optical inspection. The optical method makes it easier for manufacturers to detect and correct the errors to avoid recurrence.