AOI

AOI = Automated Optical Inspection. AOI uses optical images and pattern matching technology to inspect products. TRI's AOI systems are developed to target light, thin and/or high-density electronic printed circuit boards and assemblies (PCBs/PCBAs). AOI is a non-destructive process that can detect defects without the use of expensive fixtures and without electrical testing.

In the SMT (surface-mount technology) production process, AOI can replace visual inspection performed by human operators and standardize the inspection process. AOI can test end products as well as products in process.

Human inspection can be unstable and affected by many variables. AOI not only standardizes the process, but also reduces the inspection time and maintenance cost, and raises manufacturing capability and quality.

The Repair Station is a stand-alone system closely integrated with the AOI system. The AOI system outputs inspection results to the Repair Station, where users can confirm the defect and/or repair the PCB immediately. The Repair Station offers a graphical user interface for easy and quick use. Also, the Repair Station provides a complete statistical process control (SPC) function for data collection and can output reports in an MS-Excel format for greater flexibility in managing the data.

TRI provides both inline and desktop AOI.

TRI's AOI systems can be located on the SMT manufacturing line either pre-reflow or post-reflow, or both. No software or hardware change is needed.

TRI's AOI detects the following defects in components and solder joints -- Component: Missing, Tombstone, Billboard, Polarity, Skew, Marking, Defective Solder Joint: Insufficient/excess solder, Bridge, Through-hole pins, Lifted lead, Golden finger scratch/blur

Resolution means the real size a pixel represents. It is usually represented in micrometers (um). For example, 10um resolution means that one pixel on screen is 10um actual distance. The smaller the number means the higher the resolution, but the higher resolution only can be achieved at a slower speed. Users can choose the resolution that best fits their production process based on the component size and the cycle time.

The resolution of a TRI AOI system is chosen by the customer when they order the machine. It is fixed by the specified hardware. If a customer needs to change the resolution, TRI does provide this service. Please contact your TRI representative or authorized agent.

Inline AOI systems are equipped with an automatic conveyor system for both the left and right sides (left in/right out or right in/left out). Inline systems also can provide input and output signals to the previous or next stations in the manufacturing process. An inline AOI system can be a station in an automated production line, can link with a loader/unloader or can be a standalone work station. TRI's desktop AOI systems include all of the same imaging technology as inline systems, but are designed to be independent work stations. An operator manually loads and unloads the boards for inspection. Desktop AOI, with its compact size, can easily be located/relocated anywhere on the factory floor.

Basic knowledge of computer operation and the SMT production process are necessary. Also, a knowledge of optical inspection techniques is recommended. These courses are included in TRI's basic training program.

When used properly, no. During machine operation, the operator must not put any part of his/her body into the AOI system to avoid injury due to electrical or mechanical causes. Also, looking directly at the light source, laser, or sensors should be avoided. Shut down the system completely before performing any maintenance. There is no harmful radiation created by TRI's AOI systems.

The warpage that is ±3mm compared with the datum plane does not affect inspection. For a greater amount of warpage, it is suggested to use support pins to reduce the effect of warpage.

TRI uses the MS- Windows operating system on the system computer. Inline systems are equipped with a Human Computer Interface (HCI), which offers multi-language support.

TRI's AOI uses the leading top-based design for board clamping. The PCB is clamped upward to align with the clamping mechanism, thus the distance between the top side of the PCB and the camera is fixed: focus and inspection are not affected by the thickness of the PCB.

TRI's board-clamping mechanism is motor-driven and does not need air input.

TRI's software offers a self-checking function, so users can test some functions at any time. Optical calibration is suggested to be performed once an year. This can only be performed by a TRI or TRI-certified engineer.

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