Strip Module Working Group Meeting

16th May 2012

Hybrids

A Greenall

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

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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

ABCN-25 Shield-less Hybrid

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)

SPin

SPout

SPin SPout

STAR Point

Hybrid PowerReturn Return

Pi-filter Pi-filter2.5V/10A

SPout

SPin

V+

V-

V+

V-2 x 10µF22µF

12nH

2 x 10µF 22µF

12nH

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Double Trigger Noise (DTN) Results

1fC AC 0.75fC AC 0.5fC AC 1fC DC 0.5fC DC

Hybrid 0 0 295 39125 0 25229

Hybrid 1 8 1150 57005 1 38472

Hybrid 2 41 2690 107167 1 48254

Hybrid 3 144 3199 120743 60 52275

DTN @ 0.5fC AC

Results obtained with Hybrids 2/3 AC referenced to sensor – they

should be DC

Hybrids now DC referenced occupancy globally reduced

Hybrid 0

Hybrid 1

Hybrid 2

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

1fC 0.75fC 0.5fC 0.5fC

Hybrid 0 0 0 17 75

Hybrid 1 0 0 57 112

Hybrid 2 0 0 998 641

Hybrid 3 0 0 539 292

BCC shield connection only

Adding 2nd sensor HV contact

DTN @ 0.5fC AC

Still see evidence of noise bands –

see DTN plot

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Out of the box results

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

Global reduction of ≥50e is now achieved compared to original

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Noise reduction of ~40e achieved

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

Irradiation of new family of NTCs

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•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

Summary

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