Changes

Of course, defect detection on assembled PCB's is a matter that is strictly related to the core business of DAVE Embedded Systems. Also, PCB assembling is an industrial process under the full control of the company itself. This was a great help for creating a dataset of defected boards. As detailed in the rest of the section, our assembly line was configured purposely to generate a relatively high rate of defects in a controlled fashion on a limited numbers of boards. For this first attempt, 5 panels are were prepared, each one containing 4 PCBs of the same type and with same template project i.e. the same bill of materials (BOM) for the [https://www.dave.eu/en/solutions/system-on-modules/diva-som ''DIVA series 2SoM'']. In this case, it has been was decided to mount components only on ''top'' side of the PCB. Furthermore, in order to reduce complexity and simplify the problem for this test, anomalies generation is restricted to 2 contacts SMD passive components i.e. resistors, capacitors, and inductors. The table below reports all plausible anomalies that can be generated by editing the standard template project containing all the positions of the components for the pick-and-place (P&P ) machine, decreasing or increasing the quantity of solder deposited by the serigraphy screen printer on the panel or that can be generated directly by the operator.

*'''Manhattan''': the component is in place , but it is erected horizontally (the operation has to be performed manually by the operator).*'''Shift x-axis''': the component is in place according to the PCB design , but it shows a small shift along its x-axis.*'''Shift y-axis''': the component is in place according to the PCB design , but it shows a small shift along its y-axis.*'''Shift&Rotation (x+z-axes)''': the component is in place according to the PCB design , but is shifted along its x-axis and rotated along its z-axis.*'''Rotation (z-axis)''': the component is in place according to the PCB design , but it is rotated along its z-axis.

The same template for the P&P machine is used for all the 5 panels, but some of them use a different configuration for the program of the serigraph machinescreen printer:

After completing the assembly of all 5 panels, a visual inspection was performed with the a traditional AOI machine. A total amount of '''832 anomalies''' were found and the corresponding unmarked images were saved for dataset building.