The Benefits of AOI in SMT Assembly


When surface mount technology is used on printed circuit boards, quality control becomes exceptionally important. During SMT assembly, short lead and leadless components are assembled on the printed circuit board. Even the slightest defects in the SMT assembly process can cause serious concerns about the manufactured electronics. With AOI technology, inspecting the SMT assembly process is easier, faster, and more efficient. Let’s examine the benefits of using an AOI machine in SMT assembly.

Reasons to Apply AOI in SMT Environments

You should consider implementing an AOI machine in the SMT assembly environment for several reasons. We’ll cover some of the reasons and benefits that you can obtain below:


  • Cost reduction: One of the most important benefits is that AOI can help reduce the cost of inspection processes in an SMT assembly environment. While the initial investment may seem big, in the long run, it saves significant time and reduces the need for multiple inspectors.
  • Reliability: Another important reason to incorporate an AOI machine is its reliability. Detecting defects in the SMT environment early on is incredibly important. An AOI machine is highly reliable and accurate in identifying these defects and errors, saving you from serious manufacturing faults later on.
  • Ease of use: The initial programming phase is relatively quick and easy to complete. Following this process, the AOI machine becomes easy to use in your production line.


Core Fundamentals of AOI

Certain core elements form part of an AOI machine. It’s important to understand the role that each of these fundamental parts plays – and how it contributes to the overall efficacy in PCBA manufacturing and SMT assembly:


  • CCD image system:The CCD image system helps capture circuit board photographs. A high-resolution lens is generally used to ensure even the finest details can be captured by the AOI machine. Better quality images help to ensure defects can be identified with greater accuracy.
  • Servo-actuated control system: Implementing a servo-actuated control system helps increase the overall precision and accuracythat AOI machines can provide in the manufacturing process.
  • Image processing system:Finally, an image processing system analyzes the image that was taken to identify any potential defects that may be present. The results are then displayed, and you can use this data to correct any defects early in manufacturing.


Information That can be Delivered Through an AOI Machine

An AOI machine is capable of delivering a diverse range of information related to a printed circuit board, as well as in areas of SMT assembly. Some of the data that can be identified with these machines include:


  • Components that are missing or placed incorrectly
  • Problems with bridging and paste smearing
  • Chips that are missing or offset to the wrong position
  • Stains and scratches that are present on the printed circuit board
  • Solder that is too thin or not correctly placed on the board
  • Spacing violations that may cause problems in the final electronic product
  • Circuits that may cause a short when power is connected to the board
  • Defects in the orientation of chips and other components that are assembled on the board
  • Lifted leads that may cause problems with the connection between two elements


These are all defects and mishaps that can become costly when they are not taken into consideration and addressed during manufacturing. By identifying these particular problems, you can take the board back to the SMT assembly environment and have them corrected. The board can then be placed back in the AOI machine to ensure any previous faults identified have been corrected. It’s also an important opportunity to identify cases where some of the required components are not installed on the board.



Quality control is a critical element in the manufacturing process, and with Maker-ray at your side, you can ensure no defects go unnoticed. Maker-ray specializes in the production of various AOI machine options, giving you more versatility when incorporating these devices into the manufacturing process. Simply reach out to learn more about the SMT, THT, and Coating AOI machine solutions that Maker-ray offers.