1. WP6 meeting 30/07/2013

2. Status of flex prototypes production New laser soldering tests Discussion on mass production schedule

3. Flex prototypes FHR order: 2 foils with 3 circuits, 25  m apical from Rui (obtained removing Cu layers bu chemical etching) + 15  m Al (compatible with chemical etching procedure at CERN), issue on first foil coated (Al peels off at the edge) due to bad quality of apical? Next: another test using 50  m apical from FHR and15  m Al + 2 foils coated with 25  m Al Goals: 1) check chemical and laser etching on two Al thickness; 2) electrical tests Delivered ….

4. Differential impedance simulations

5. New laser soldering tests Test performed at Neu Ulm not conclusive, issues with: – soldering grid design – Single chip flex: holes too small (160  m), metallisation? – Small SnAg balls (200  m) Laser soldering system rented at Dr Mergenthaler to optimize parameters (temperature profile, beam focusing) System to be installed in DSF, safety requirements to be verified next week with laser safety officer (actions for DSF?) Aim at starting at the beginning of September

6. Single chip flex, w/o coverlay, no soldering grid

8. Issues: -Mismatch between microscope and metallurgy pictures numbering -Most of solderings does not wet the chip pad Single chip flex, w/o coverlay, no soldering grid

9. Planning of staves assembly Inner barrel – 48 staves x 2 + 10% ~ 110 staves – 990 chips, 49500 solderings Outer barrel – 1602 modules +10% ~ 1800 modules – 25200 chips, 1260000 solderings

10. Planning of staves assembly Assembly sequence hypothesis: 1)Placement of chips on vacuum table (auto): 9x10” ~ 90” (14 chips: 140”) 2)Placement of flex on vacuum table + grid on flex (man, pinholes): 300” 3)Alignment (auto): 300” 4)SnAg balls deposition + soldering of one chip (auto): 300” + 50x 10”= 800” Total per IB module: 2h 11’ -> 30 d for full IB Total per OB module: 3h 19’ -> ~ 750 d for full OB (1 d = 8h)

11. Planning for Layers 0, 1, 2, 3 and 4

12. Short term plans (for TDR final version) By the end of September: – Preliminary results on technology for Al flex production, chemical vs laser engraving – Preliminary results on chips embedding – Laser soldering: optimization of process parameters, tooling Critical issues – Design of flex depends on chips specs not available (i.e. power consumption: if 25 mW/cm 2 instead of 250 mW/cm 2 less constraints on Al thickness?) – Al flex processing dependence on Al layer thickness – Study of electrical characterization/ performance of flex