Printed electronics means manufacturing electronics by utilising traditional printing methods. In comparison to traditional graphic printed products, the quality of the print becomes more significant when printing electronics. Flawlessness of the imprint is very important to ensure fully functional end products. This thesis studies measuring register accuracy between separate print units in printed electronics printing press by using a machine vision system. One such system is described in this thesis. As printing technologies and materials evolve, throughput of printing lines increases and the sizes of printed details get smaller. This places increasing challenges on quality assurance. Today's technology enables smallest printed feature sizes between 20 and 100 micrometres depending on the used printing technique. Reaching 10 micrometre scale is likely to be achieved in the near future. The system described in this thesis has a resolution of 11 to 15 micrometres depending on the circumstances. Software compatible with the described system was developed alongside this thesis. The software uses machine vision methods to find register marks from pictures captured by the camera in the system. The software then uses these marks to determine the offset between marks printed in different printing units. The calculated offset is the print's register error. The performance and suitability for register error measurement of both the software and the entire system are verified experimentally in this thesis.
|Place of Publication||Oulu|
|Publication status||Published - 2013|
|MoE publication type||G2 Master's thesis, polytechnic Master's thesis|
- optical inspection
- machine vision
- computer vision
- printed electronics