Executive summary from Bonding WG Meeting 21 Oct 2003

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Executive summary from Bonding WG Meeting 21
Oct 2003

• Salvatore Costa
• INFN Catania

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Summary of recent TIBTOB prod
3
Module Pull Tests (1)
4
Module Pull Tests (2)
Firenze
To
Pd
Santa Barbara
5
Module Pull Tests (3)
Firenze
To
Pd
Santa Barbara
Bari
Pisa
6
Module Pull Tests (4)
Santa Barbara
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Highlights from Center Reports

• AACHEN
• Just completed pilot run for TEC with 10 R6
  frames. Bonded and tested the 10 frames within
  two days. No problems with the P.A to sensor
  bondings. Had 1-2 failures (5-8 lift-offs)
  during automatic bonding sensor-to-sensor.
  Investigating this with HesseKnipps.
• BARI
• Got 48 Hyb in Sep. Bonded APV-PA for 11. New PAs
  pose no bonding problems.
• CATANIA
• Both Hughes are back in operation and equipped
  with fresh wire, after fixing hw damage suffered
  in moving from old to new Dept. Building
• Will begin bonding Test Structures, Modules after
  this TK Week
• CERN
• Whiskers still a problem in Bonding APVs to
  Planar PA with Delvotec).It appears that KS
  8090/8060 do not have this problem. So, UCSB OK.
  
• FNAL has accepted to help in bonding TEC 2,5,6).
  Hybrid bonding at CERN is otherwise OK. If FNAL
  does pick up 20 of PA-APV bonding, will need to
  bond about 24 hybrids per day instead of 35/day.
• PISA
• Showed Pull test results for Sensor qualification
  on 32 new Test Structures (16 STM and 16
  Hamamatsu).
• Over 898 channels total pull tested, FBL or SBL
  occurs on 16 strips (1,78 )
• An overall summary of 199 Test Structures (145
  STM and 54 Hamamatsu) indicates that over 5560
  channels total pull tested, FBL or SBL occurs on
  118 strips (2,12 )

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Highlights from Center Reports

• Reported on mechanical stress tests of proposed
  (now adopted) Hyb cable stiffener. 3 out of 4
  Modules were retrofitted with stiffener and all 4
  tortured with many different types of mechanical
  stress. Subsequently tested, the 3 with stiffener
  showed normal electric behavior, while in the one
  without 6/13 lines were lost, besides exhibiting
  evident cracks at optical inspection.
• SANTA BARBARA
• Received first Hybrids with Planar PA's, bonded,
  and didn't see any of the "whiskering" problem
  that Alan had found.
• Received first 6-chip hybrids and bonded 8 of
  them. Also bonded 5 of the 4-chip hybrids. (All
  the stereo hybrids received were already bonded).
• Bonded 2 6-chip modules, 3 stereo modules.
• All modules have been fully tested with ARCS and
  LT system
• Both pulsed and continuous LED tests taken
• ALL of 42 strips designated in DB as bad-CAC and
  isolated had regular test results (passed)
• No problem seen with these channels
• Also worked (Tony) on adding stiffener to Hybrid
  cable ?test ?also OK.
• STRASBOURG
• Working on Just received 15 modules of the ring
  7.
• VIENNA
• Will need to adapt jig as soon as they receive
  Modules with new frame
• ZURICH
• Received 4 Modules which all failed test after
  ground bonding

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Alans Comments on mod to TEC modules to avoid
bond breakage

• TEC module design modified, adding a ceramic
  piece to be glued between Sen PA spacer (and
  Sen-Sen). Ceramic piece and glue joint are
  exactly where one wants to support the module for
  bonding. Thus, bonding jigs must be modified.
  Alan would like to know how and how it works.
• TID modules may also have the same risk of bond
  breakage so some solution will have to be devised
  for them as well. Alan would like to know that
  solution and how it works.

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Which strips should the Bonders skip because
of known Sensor defects(a question from Bonding
WG to Sensor experts)
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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 3 34 35 36 37 skip isolated
  3,
• skip all but lowest in 34-37 chain, or bond only
  34

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Isolated bad-CAC strips

• Recently questioned, because
• They should fail the Pinhole search with
  Karlsruhes 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
• gtgtgtgtgtgtgtgtgtgtgtgt LED test NEVER failed ltltltltltltltltltltltlt
• We wanted to learn more on bad I_DIEL bad C_AC
  strips
• Ive performed a comprehensive study of the bad
  stripsand
• 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!

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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
• I_DIEL value (in nA) for all strips
• List of bad strips for I_DIEL
• C_AC value (in pF) for all strips
• List of bad strips for C_AC

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(No Transcript)
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Bad strips study

• Accounting out of 2420 Sensors
• Bad-I_DIEL strips are 2898 in total (1.2 per
  Sensor in average)
• Bad-C_AC strips are 10251 in total (4 per
  Sensor in average)
• Of these, 3707 are isolated, 6544 are chain
  (shorted)
• Out of the 3707 isolated bad-C_AC strips
• 1146 (30) are also flagged as bad-I_IDIEL
• 2561 (70) are not flagged as bad-I_IDIEL
• Plot Distributions of
• I_DIEL for good-I_DIEL strips (expect 0)
• I_DIEL for bad-I_DIEL strips (expect gt0, but )
• relative C_AC for isolated bad-C_AC strips
• (expect small values, lt1)
• relative C_AC for chain bad-C_AC strips
• (expect integer multiples, 2, 3,, but )
• IDIEL for isolated bad-C_AC strips which are also
  in bad-I_DIEL list
• IDIEL for isolated bad-C_AC strips which are not
  in bad-I_DIEL list

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I_DIEL for good strips (1)

• Plotted for 869,158 strips
• (approx 1700 Sensors)
• Extends to 1mA
• but peaks near 0 as expected

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I_DIEL for good strips (2)

• Plotted for 869,158 strips
• (approx 1700 Sensors)
• 857,754 (99 ) are within 1 nA

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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_DIEL0.00
• There are a few negative values

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I_DIEL for bad-IDIEL strips (1)

• 2400 Sensors
• 2898 bad-IDIEL strips
• (1.2/Sensor)
• Extends to 1.2x107, but most are much lower

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I_DIEL for bad-IDIEL strips (2)

• 2400 Sensors
• 2898 bad-IDIEL strips
• (1.2/Sensor)
• 0ltI_DIELlt1.2x107nA
• 1576 (54)
• 1mAltI_DIEL1mA

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I_DIEL for bad-IDIEL strips (3)

• 2400 Sensors
• 2898 bad-IDIEL strips
• (1.2/Sensor)
• 0ltI_DIELlt1.2x107nA
• 1576 (54)
• 1mAltI_DIEL1mA
• 797 ( 27)
• 0.1nAltI_DIEL1mA
• A peak at 100 nA

?
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I_DIEL for bad-IDIEL strips (4)

• 2400 Sensors
• 2898 bad-IDIEL strips
• (1.2/Sensor)
• 0ltI_DIELlt1.2x107nA
• 1576 (54)
• 1mAltI_DIEL1mA
• 797 ( 27)
• 0.1nAltI_DIEL1mA
• 476 (16) have normal
• (as 85 of good strips) I_DIEL lt 0.1nA !!!
• Bond or not?

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Relative C_AC for Isolated bad-CAC strips (1)

• 2400 Sensors
• 10251 bad-C_AC strips
• (4/Sensor)
• 3707 Isolated
• (1.5/Sensor)
• Extends from
• -10000lt lt2000
• but most are much lower

C_AC ltC_ACgt
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Relative C_AC for Isolated bad-CAC strips (2)

• 2400 Sensors
• 3707 Isolated bad C_AC strips
• (1.5/Sensor)
• -10000lt lt2000
• 3566 (96)
• -2 lt lt 2
• Some negative values
• Peaks at 0 and 0.6
• Bond or not?

C_AC ltC_ACgt
C_AC ltC_ACgt
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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)

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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

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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

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I_DIEL for Isolated bad-CAC strips (4)

• Out of the 2561 not in bad I_DIEL list
• 2556 (100)
• 0 lt I_DIEL lt 1nA
• 2358 (92) have normal
• 0 lt I_DIEL lt 0.1nA
• Only 193 (8) have
• 0.1nA lt I_DIEL lt 1nA
• (not shown)
• Bond or not?

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Relative C_AC for Chain bad-CAC strips (1)

• 2400 Sensors
• 10251 bad-C_AC strips
• (4/Sensor)
• 6544 Chain
• (2.7/Sensor)
• Extends from
• -200lt lt1000
• but most are much lower

C_AC ltC_ACgt
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Relative C_AC for Chain bad-CAC strips (2)

• 2400 Sensors
• 6544 Isolated bad C_AC strips
• (2.7/Sensor)
• -200lt lt1000
• 6508 (99)
• -2 lt lt 8
• Expected integers (2,3,4) Some do, but most have
  lt1 with distrib Isolated
• Our rule that assumed them to be all shorts might
  be too naïve!

C_AC ltC_ACgt
C_AC ltC_ACgt
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Relative C_AC for Chain bad-CAC strips (3)

• 2400 Sensors
• 6544 Isolated bad C_AC strips
• (2.7/Sensor)
• -200lt lt1000
• 5889 (90)
• -2 lt lt 2
• Neighbors, but isolated?
• 619 (10)
• 2lt lt8
• There is a peak at 2.5
• Actually shorted?

C_AC ltC_ACgt
C_AC ltC_ACgt
C_AC ltC_ACgt
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Summary Request for guidance

• Strips in bad-IDIEL list
• 16 do not seem to have a bad I_DIEL bond or
  skip?
• Isolated strips in bad-CAC list
• They all seem to have bad C_AC (relative C_AC
  mostly lt1)
• 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
• Chain strips in bad-CAC list
• Only 10 of these seem to actually be shorted
  (relative C_AC gt1)
• 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 ltsome threshold (1?), treat them the same way
  as the isolated
• If gt , apply the current rule for shorts i.e.
  bond only the 1st in chain
• In all cases we ask Sensor experts for guidance