Strip Module Working Group Meeting 16 th May 2012 Hybrids A Greenall

1. Strip Module Working Group Meeting 16th May 2012 Hybrids A Greenall

2. Outline • ABCN-25 Shield-less hybrid • Changes being made • Current status • Serial Powering of Modules • Latest results with “Chain of Modules” configuration for a single module • ABC130 • First pass at Pad ring • Iterative process between hybrid and asic designers – converging to a preferred geometry • See Francis’s talk... • Irradiation of new family of NTCs • Prerequisite for use with HCC

3. ABCN-25 Shield-less Hybrid • Primarily being used as a test vehicle for differing flavoured hybrid attachment tabs • Trying to identify a tab which does not compromise the planarity of the hybrid after reflow • Each of the 8 hybrids, on a panel, comes with a different flavoured tab • Tabs differ in geometry, builds (Cu inlay) and cut profile • Other changes taken on board • Hybrid build now reduced to 4 layers (5th shield layer dropped) • Use of blind vias through out • Final opportunity to confirm that shield is not needed before we move to ABCN130 • Other (minor) changes taken on board: • Wshunt disable line now hard-wired to VDD (no longer bussed) • CLKmode80 hard-wired to VDD on panel (fixed to 80MHz Dclk) • Mshunt VDD monitor point now revised so that 3 (mutually exclusive) locations are now available • Far-end (as before), centre of hybrid or hybrid power entry – set by wire bond • Via chains added to panel – allows QA of vias by use of (4-wire) resistance measurement • 3 chains added of ~190 vias/chain • Via connections monitored are L1-L2, L1-L3 and L1-L4 • Minor changes to solder resist (requested by Forest at SCIPP) • Hybrid NTCs are now brought out to 0.1” connector on panel (one per hybrid location) for monitoring • Layout and drill files for manufacture now complete • Will go for submission this week

4. Serial Powering of Modules • Request to implement “Chain of Modules” powering configuration in more sanitary manner • PCB designed, based on PPB geometry • STAR topology implemented for both power and return (centred on hybrid power feeds and not PCB) • Provides serial powered configuration for a module i.e. not serial powering of hybrids • Results in 2.5V (~10A) across module PPB Replacement (PPBR) SPout SPin Return Return Hybrid Power SPin SPout STAR Point Pi-filter Pi-filter 2.5V/10A SPin 12nH 12nH V+ V+ V- V- 2 x 10µF 22µF 22µF 2 x 10µF SPout

5. Double Trigger Noise (DTN) Results DTN @ 0.5fC AC Out of the box results Hybrid 0 Hybrid 1 Hybrid 2 Results obtained with Hybrids 2/3 AC referenced to sensor – they should be DC Hybrids now DC referenced occupancy globally reduced Hybrid 3 • Went through series of incremental changes – goal is to make electrical configuration as per new Bus cable • Identified 2nd HV connection missing off “low side “ hybrid - adding this connection brought occupancy down dramatically • Both 1fC & 0.5fC clean (0 hits) • At 0.5fC record 29, 114, 907 and 593 hits (hybrids 0 to 3 respectively) • Added 2nd “shield” connection to the cooling block at the BCC end, followed by 2nd sensor HV contact DTN @ 0.5fC AC Adding 2nd sensor HV contact Still see evidence of noise bands – see DTN plot BCC shield connection only

6. But DTN doesn’t tell the whole story... Input noise of module was originally high with normal grounding test configuration Input noise with PPBR and DC referenced hybrids – comparable to seen in the past with elevated noise Input noise with PPBR with both ends of hybrids referenced to cooling block With 2nd sensor HV contact Noise reduction of ~40e achieved Global reduction of ≥50e is now achieved compared to original

7. Irradiation of new family of NTCs • Irradiation of Hybrid NTCs for future ABC130 modules • Request from ASIC designers to revise NTC type such that the resistance at 25°C is 1kΩ • HCC temperature measuring circuit has a leakage current which introduces a DC offset • NTCs with high R could be problematic for measurement • NTCs used on present hybrids are 10kΩ • Switching to different NTC will require their qualification to expected Upgrade radiation dose • 3 candidate manufacturers identified: • Murata, Vishay and Panasonic • Current family of devices, manufactured by Semitec, don’t go below 10kΩ • Plan to irradiate the following devices plus reference, vis: • 5 x 1kΩ and 5 x 2kΩ - from each manufacturer 30 off total • 5 x Semitec (reference) • Devices will be hooked up to a multiplexed data logger for real time measurement during irradiation • To be done at CERN PS (July/August) and possibly the irradiation facility at Birmingham

8. Summary • ABCN-25 shield-less hybrid is now more or less ready for submission • Issue of planarity of tabs is being addressed • Will come as a 4 layer build – no shield (preparing for the future ABC130 hybrids) • Other minor changes taken on board (see list on slide 2 ) • Serial Powering of modules – configured as “Chain of Modules” • PCB designed with “star” topology has been demonstrated to work • Incremental changes to electrical configuration showed improving noise performance • Changes reflect configuration of new bus cables • The future for a stavelet with this adopted configuration looks promising • ABC130 first pass at Pad Ring has been done • Preliminary layout has been demonstrated to fit within the asic geometry of 6mm x 7.9mm • Irradiation of new family of NTCs • Candidate families of NTCs with lower resistance at 25°C have been identified (1kΩ at 25°C, present NTCs are 10kΩ at 25°C) • Requested for matching up to current HCC design • Will go for irradiation in summer to qualify their robustness to radiation damage