1. Measurements of the Printed Circuit Boards (PCB) Simon Gonzalez (CSU Fresno) DespinaSampsonidou ( AUTH) and Claudio Savarese(Napoli Federico II )

2. Precision of strips over large area • 5 PCBs (0.6 x 2 m2) PCBs from ELTOS at CERN. • Measurements to be taken • position of fiducial marks. • Strip pitch at different positions. Side A Side B

3. Instrument for fiducial measurements • Traveling Microscope • Microscope that travels on tracks above a table • Digital readout • Measurements can be taken down to 0.01mm (10 μm) • Used on PCB2 and PCB3 Fiducial mark Copper strip

4. Fiducial results PCB2 – (B)

5. Results for Fiducial reading • PCB2 • average fiducial to strip reading of 24.87mm and fiducial to fiducial reading of 99.97mm for side B. • average fiducial to strip reading of 24.88mm and fiducial to fiducial reading of 99.97mm for side A. • Average length from strip A edge to strip B edge 500.28mm • PCB3 • average fiducial to strip reading of 24.89mm and fiducial to fiducial reading of 99.98mm for side B. • average fiducial to strip reading of 24.88mm and fiducial to fiducial reading of 99.99mm for side A. • Average length from strip A edge to strip B edge 500.33mm

6. Instrument for Strip pitch • NA62 laser interferometer • Computer controlled laser that can take reading down to a nanometer. laser

7. Full Scan of PCB1 Full Scan 2 Full Scan 1 Full Scan 3

8. Finding the pitch • What is pitch? • Small region analysis of the full data set. pitch pitch

9. Current results Scan 1 • Other “big” peaks → multiples of 400μm • Other “small” peaks → multiples of 200μm • Misidentified local maxima

10. Current results Scan 2 measurements Gaussian

11. Problems • Some bad fiducial marks/copper strips • Laser would move along the vertical after being set

12. Conclusion • The boards are close to uniform with at most a 10μm to 50μm difference. • Short analyses are promising a pitch of 400μm • About 1250 copper Strips within the 500mm width of the board. • Work still needs to be done on the remaining boards and analyses of the full data set need to be completed.