Automated Optical Inspection (AOI) Analysis

AOI Analysis An automated optical inspection (AOI) is an analysis which canvass the solder joints for their correctness after soldering the board. As it is often the case that the camera cannot detect all the components to be inspected, it is necessary to ensure this beforehand. PCB Investigator‘s automated optical inspection provide an analysis tool for this detection of the missing inspectability.

 

AOI Analysis 2D

By using the 'AOI check' button the following window appears:

aoi_2d_mainview

 

 

    Open a PCB design first and then start the ‚AOI check‘.
  1. First you have to decide, if you want to analyze your design with a 2D or 3D inspection. However, the following section deals only with 2D inspection. If you need information about the 3D inspection, use the 3D AOI description.
  2. Enter the angle of your future automated optical inspection for the camera angle. Tolerances can be calculated using’ additional distance’. By default, this value is set to 0.00. As 2-pin components often aren´t relevant or, due to their shape, difficult to analyze , they can be excluded here. Occasionally components with very large pins are used. These pins often do not need to be checked due to their size. For this reason, enter an area in the’ Value of an area to hide huge pins’ input field that meets your requirements. You can also select the two options’ Create an aoi check layer’ and’ Color pins’. If you want an additional layer, on which the direction of inspection per pin is marked, activate ’Create an aoi check layer’.With the use of the ’Color pins’ option, the pins in the diagram displayed in color are also colored in the design.
  3. After you have adapted all values to your requirements, you can start the inspection.
  4. The inspected components and their pins are now displayed and can be sorted using the riders. The result list contains one line per pin. It contains the following information:
    • ID: Identification Number
    • Layer: Contains on which side the pin can be found
    • Component: Component name
    • Pin: Pin number
    • Shadow Component: Component that is too close to the pin
    • Distance: Shows the calculated distance
    • Checkdistance: Shows the required distance
    • Shadowcomp. Height: Shadow component height
  5. The diagram illustrates the result of the inspection.
  6. The inspection can now be saved using the ’Export Result’ option. When using the import result, an old inspection result can be loaded.
  7. If you move the mouse over the ’Help’ icon, the following picture will be displayed to explain how 2D inspection works.

 

aoi_2d_description_view

 

Example:

Doubleclick an entry shows the component J1 and the corresponding pin 8 (red colored) with too small distance to the component LDR after the 2D inspection.
aoi_2d_list_entry_on_board

AOI Analysis 3D

By using the 'AOI check' button and switching to 3D AOI the following window appears:

aoi_3d_mainview

Open a PCB design start, then the ‚AOI‘.

  1. First you have to decide,if you want to analyze your design with a 2D or 3D inspection. However, the following section deals only with 3D inspection. If you need information about the 2D inspection, use the 2D AOI description.
  2. First replace the’ laser angle’ arranged between the laser and the camera with its actual laser angle. Since the direction the laser head moves in differs during the 3D inspection, it can also be adjusted with ’horizontal’ and ’vertical’. The colouring of the affected components can be selected as required. It is also possible to graphically display the overlapping of the shadow with other components in separate layers using the’ create shadow layers’ option. So the layers show the shadow of a component in both test directions and are shown as follows.

 

aoi_3d_additional_layer

  1. After you have adapted all values and selection options to your requirements, you can start the inspection.
  2. The inspected components and their pins are now displayed and can be sorted using the riders. The result list contains one line per pin. It contains the following information:
    • ID: Identification Number
    • Layer: Contains on which side the pin can be found
    • Component: Component name
    • Shadow on: Identifier whether the shadow falls on a component body or the corresponding pin
    • Package: Package name
    • Shadow Components: Shows the component names of the components affected by the shadow
  3. The diagram illustrates the result of the inspection.
  4. The inspection can now be saved using the ’Export Result’ option. When using the import result, a past inspection result can be loaded.
  5. If you move the mouse over the ’Help’ icon, the following picture will be displayed to explain how 2D inspection works.

aoi_3d_description

Example:
Doubleclick an entry shows the component J1 and the corresponding pin 8 (red colored) with too small distance to the component LDR after the 2D inspection.
aoi_3d_list_entry_on_board