Tracker Week, CERN, Oct Oct 2003Tracker Week - Bonding WGSalvatore Costa - Catania Which strips should the Bonders skip because of known Sensor defects (a question from Bonding WG to Sensor experts)

21 Oct 2003Tracker Week - Bonding WG2 Salvatore Costa - Catania Recipe for strips to leave unbonded React only to bond immediately upstream of sensor with bad strip Skip (= leave unbonded) –All bad IDIEL (considered pinholes) (IDIEL_1_SEN_.POSITION_OF_BAD_STRIPS) –All Isolated bad CAC (believed to have high chance to develop into pinholes with irradiation) (CAC100HZ_1_ SEN_.POSITION_OF_BAD_STRIPS) –All but lowest in a bad CAC chain (believed to represent shorts) (CAC100HZ_1_ SEN_.POSITION_OF_BAD_STRIPS) CAC Example: skip isolated 3, skip all but lowest in chain, or: bond only 34

21 Oct 2003Tracker Week - Bonding WG3 Salvatore Costa - Catania Isolated bad-CAC strips Recently questioned, because: They should fail the Pinhole search with Karlsruhe’s LED system But some Italian Labs and UCSB have bonded them anyways in this initial Module Prod for investigation purposes and found no evidence of pinholes: >>>>>>>>>>>> LED test NEVER failed <<<<<<<<<<<< We wanted to learn more on bad I_DIEL & bad C_AC strips  I’ve performed a comprehensive study of the bad strips…and…  as a result of this study, we are no longer confident on any part of our current rule to skip bad strips  So we are turning to Sensor experts for guidance!

21 Oct 2003Tracker Week - Bonding WG4 Salvatore Costa - Catania Bad strips study In DB there are relevant data, in Tables IDIEL & CAC100HZ, for 2427 Sensors For 7 Sensors, data are nonsense  2420 Sensors are included in this study For each of 2420 sensors, download from DB: 1)I_DIEL value (in nA) for all strips 2)List of bad strips for I_DIEL 3)C_AC value (in pF) for all strips 4)List of bad strips for C_AC

21 Oct 2003Tracker Week - Bonding WG5 Salvatore Costa - Catania

21 Oct 2003Tracker Week - Bonding WG6 Salvatore Costa - Catania Bad strips study Accounting: out of 2420 Sensors… 1.Bad-I_DIEL strips are 2898 in total (~1.2 per Sensor in average) 2.Bad-C_AC strips are in total (~4 per Sensor in average) 1.Of these, 3707 are ‘isolated’, 6544 are ‘chain’ (‘shorted’) 2.Out of the 3707 isolated bad-C_AC strips: (30%) are also flagged as bad-I_IDIEL (70%) are not flagged as bad-I_IDIEL Plot Distributions of: 1.I_DIEL for good-I_DIEL strips (expect ~0) 2.I_DIEL for bad-I_DIEL strips (expect >0, but… ) 3.‘relative’ C_AC for isolated bad-C_AC strips (expect small values, <1) 3.‘relative’ C_AC for chain bad-C_AC strips (expect integer multiples, 2, 3,…, but… ) 4.IDIEL for isolated bad-C_AC strips which are also in bad-I_DIEL list 5.IDIEL for isolated bad-C_AC strips which are not in bad-I_DIEL list

21 Oct 2003Tracker Week - Bonding WG7 Salvatore Costa - Catania I_DIEL for good strips (1) Plotted for 869,158 strips (approx 1700 Sensors) Extends to ~1  A but peaks near 0 as expected

21 Oct 2003Tracker Week - Bonding WG8 Salvatore Costa - Catania I_DIEL for good strips (2) Plotted for 869,158 strips (approx 1700 Sensors) 857,754 (99 %) are within 1 nA

21 Oct 2003Tracker Week - Bonding WG9 Salvatore Costa - Catania I_DIEL for good strips (3) Plotted for 869,158 strips (approx 1700 Sensors 742,388 (85 %) are within 0.1 nA ~560,000 (65%) have I_DIEL=0.00 There are a few negative values

21 Oct 2003Tracker Week - Bonding WG10 Salvatore Costa - Catania I_DIEL for bad-IDIEL strips (1) 2400 Sensors 2898 bad- IDIEL strips (~1.2/Sensor) Extends to 1.2x10 7, but most are much lower

21 Oct 2003Tracker Week - Bonding WG11 Salvatore Costa - Catania I_DIEL for bad-IDIEL strips (2) 2400 Sensors 2898 bad-IDIEL strips (~1.2/Sensor) 0< I_DIEL <1.2x10 7 nA 1576 (54%) 1  A< I_DIEL ≤1mA

21 Oct 2003Tracker Week - Bonding WG12 Salvatore Costa - Catania I_DIEL for bad-IDIEL strips (3) 2400 Sensors 2898 bad-IDIEL strips (~1.2/Sensor) 0< I_DIEL <1.2x10 7 nA 1576 (54%) 1  A< I_DIEL ≤1mA 797 ( 27%) 0.1nA< I_DIEL ≤1  A A peak at ~100 nA ?

21 Oct 2003Tracker Week - Bonding WG13 Salvatore Costa - Catania I_DIEL for bad-IDIEL strips (4) 2400 Sensors 2898 bad-IDIEL strips (~1.2/Sensor) 0< I_DIEL <1.2x10 7 nA –1576 (54%) 1  A< I_DIEL ≤1mA –797 ( 27%) 0.1nA< I_DIEL ≤1  A 476 (16%) have ‘normal’ (=as 85% of good strips) I_DIEL < 0.1nA !!!  Bond or not?

21 Oct 2003Tracker Week - Bonding WG14 Salvatore Costa - Catania Relative C_AC for Isolated bad-CAC strips (1) 2400 Sensors bad-C_AC strips (~4/Sensor) 3707 Isolated (~1.5/Sensor) Extends from < <2000 but most are much lower C_AC

21 Oct 2003Tracker Week - Bonding WG15 Salvatore Costa - Catania Relative C_AC for Isolated bad-CAC strips (2) 2400 Sensors 3707 Isolated bad C_AC strips (~1.5/Sensor) < < (96%) -2 < < 2 Some negative values Peaks at ~0 and ~0.6  Bond or not? C_AC C_AC

21 Oct 2003Tracker Week - Bonding WG16 Salvatore Costa - Catania I_DIEL for Isolated bad-CAC strips (1) 2400 Sensors 3707 Isolated bad C_AC strips (~1.5/Sensor) 1148 (30%) also in bad I_DIEL list I_DIEL Distributions are similar to the whole bad- I_DIEL ones in all scale ranges (as expected)

21 Oct 2003Tracker Week - Bonding WG17 Salvatore Costa - Catania I_DIEL for Isolated bad-CAC strips (2) 2400 Sensors 3707 Isolated bad C_AC strips (~1.5/Sensor) 1148 (30%) also in bad I_DIEL list I_DIEL Distributions are similar to the whole bad- I_DIEL ones in all scale ranges (as expected)  Picked in bad IDIEL list

21 Oct 2003Tracker Week - Bonding WG18 Salvatore Costa - Catania I_DIEL for Isolated bad-CAC strips (3) 2400 Sensors 3707 Isolated bad- C_AC strips (~1.5/Sensor) 2561 (70%) not in bad I_DIEL list I_DIEL Distributions are similar to the whole good-I_DIEL ones in all scale ranges

21 Oct 2003Tracker Week - Bonding WG19 Salvatore Costa - Catania Out of the 2561 not in bad I_DIEL list: 2556 (~100%) 0 < I_DIEL < 1nA 2358 (92%) have ‘normal’ 0 < I_DIEL < 0.1nA Only 193 (8%) have 0.1nA < I_DIEL < 1nA (not shown)  Bond or not? I_DIEL for Isolated bad-CAC strips (4)

21 Oct 2003Tracker Week - Bonding WG20 Salvatore Costa - Catania Relative C_AC for Chain bad-CAC strips (1) 2400 Sensors bad-C_AC strips (~4/Sensor) 6544 Chain (~2.7/Sensor) Extends from -200< <1000 but most are much lower C_AC

21 Oct 2003Tracker Week - Bonding WG21 Salvatore Costa - Catania Relative C_AC for Chain bad-CAC strips (2) 2400 Sensors 6544 Isolated bad C_AC strips (~2.7/Sensor) -200< < (99%) -2 < < 8 Expected integers (2,3,4…) Some do, but most have <1 with distrib ~ Isolated:  Our rule that assumed them to be all shorts might be too naïve! C_AC C_AC

21 Oct 2003Tracker Week - Bonding WG22 Salvatore Costa - Catania Relative C_AC for Chain bad-CAC strips (3) 2400 Sensors 6544 Isolated bad C_AC strips (~2.7/Sensor) -200< <1000  5889 (90%) -2 < < 2  Neighbors, but ‘isolated’?  619 (10%) 2< <8  There is a peak at 2.5  Actually shorted? C_AC C_AC C_AC

21 Oct 2003Tracker Week - Bonding WG23 Salvatore Costa - Catania Summary & Request for guidance 1.Strips in bad-IDIEL list:  16 % do not seem to have a bad I_DIEL: bond or skip? 2.Isolated strips in bad-CAC list: –They all seem to have bad C_AC (‘relative’ C_AC mostly <1) –30 % are also in bad-IDIEL list –70 % are not in bad-IDIEL list –92% of those not in bad-IDIEL list have indeed good I_DIEL, 8% slightly high I_DIEL, almost none outrageously high I_DIEL –Those tested with LED pinhole search, all pass it  We wonder if we should bond these 3.Chain strips in bad-CAC list: –Only 10% of these seem to actually be shorted (‘relative’ C_AC >1) –Most (90%) behave just like the isolated ones  We wonder if we should bond or skip these or treat them in a more sophisticated way, such as: compute relative C_AC, then  If <some threshold (1?), treat them the same way as the isolated  If >, apply the current rule for shorts i.e. bond only the 1 st in chain In all cases we ask Sensor experts for guidance If adopted, new v.3.2 of DB I/F needed to implement new rules