CMS Tracker Week, CERN, 24-28 Oct 2005 26 Oct 2005 CMS Tracker Week - Module Product ion Salvatore Costa - Catania Report from Module Bonding Working Group Salvatore Costa Università di Catania and INFN – Sezione di Catania
Report from Module Bonding Working Group. Salvatore Costa Universit à di Catania and INFN – Sezione di Catania. Outline. Pull Test results Open issues Some peculiar failures. Global review of Module bonding quality that is, Module Pull Test results. # Modules Pull Tested. - PowerPoint PPT Presentation
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ModProd Mtg*
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CMS Tracker Week, CERN, 24-28 Oct 2005
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that is,
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CMS Tracker Week, CERN, 24-28 Oct 2005
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CMS Tracker Week, CERN, 24-28 Oct 2005
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Review of established practices in EU and US
Preparation for it in Italy
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v. 6.0
v. 6.0_US
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Conductive Glue dots between gold pad and Sensor (at Gantry)
Conductive Glue reinforcement over gold pad and Sensor (normally at
Gantry, occasionally at Bonding)
Bonds without encapsulation (at Bonding)
Bonds with encapsulation (at Bonding)
Current established practice:
US: 1 + 4 [existing TOB modules retrofitted]
Reason for reinforcement (EU) or encapsulation (US):
Bonds on back are considered at higher risk of being damaged when
modules mounted on rods or petals because people’s attention is
focused on front and the back may get neglected.
CMS Tracker Week - Module Production
Slide *
Material and Preparation
Sylgard 186 Silicone Elastomer, 2 part kit, 10:1 mixing ratio
(manufacturer: Dow-Corning)
Mixing cups
Mixing sticks
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Slide *
Dispensing Equipment
Pneumatic glue dispenser with foot pedal and timed pulse option
(manufacturer: EFD model: Ultra 1400) www.efd-inc.com
3ccm syringe barrel and piston (EFD)
Smooth-flow tapered tips, gage 20 (EFD)
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Slide *
Set up Equipment
Base plate (UCSB design), to hold the module on a module carrier
upside down
Plastic trowel (UCSB design), to spread the encapsulant over the
wirebonds and to keep the height of the encapsulant below the
maximum height
Stereo microscope (optional)
Slide *
Mix encapsulant, degas the mixture and fill syringe
Set pneumatic dispenser to 15 psi and 1 second dispense time
Set module in carrier upside down onto base plate
Dispense a line of encapsulant across the width of the
wirebonds
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Slide *
Procedure II
Position the trowel with one leg on the sensor, one leg on the
kapton
Spread the encapsulant over all 15 wirebonds by sliding the trowel
across the bonds
Once the trowel is past the wirebonds, lift it up and clean it off
with a dry tissue paper
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Procedure III
Check that all wirebonds are covered completely with the
encapsulant (this can be done with or without a stereo
microscope)
If necessary apply more silicone and repeat the troweling
procedure
Cure for 24 hours with the backside of the module facing up to
avoid beading up of the encapsulant
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9.unknown
M.Krammer:
no bond encapsulation experience in EU TEC community: use
conductive glue reinforcement
All tests OK
This procedure is now officially requested by TEC to Italy
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How is Back bonding going?
Aachen: Vibration test of backplane HV bonds: with additional glue
near bonds, but bonds bare, in one module some bonds broke, in
another module no bonds broke. In modules with encapsulated bonds,
none broke.
Strasbourg: Bonded (in hole) 16 modules electrically OK
Vienna: Bonded (in hole) 80 modules previously front-bonded, using
special supports that hold module carrier all around: sensors not
supportedNo problems.
Hamburg: Not started yet since the backplane jigs are not done
before next week. For the last weeks have reinforced the glue
connection on the backplane with conductive glue, for some modules
where this had not been done before at the Gantries.
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Recipe for TEC Mod prod in Italy
At the end of the Bonding Meeting, I conveyed its outcome at the
Gantry Meeting…
Bari has agreed to use conductive glue under HV pad when assembling
modules
Bari has agreed to place conductive glue reinforcement over the
“top” of the T-shaped pad
Bonding centers will bond “in the hole” without encapsulation
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CMS Tracker Week, CERN, 24-28 Oct 2005
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IV failures:
Affect modules not randomly in time, but in concentrated
clusters:
Recently: 5/53 in Aachen, 4/36 in Catania
Had also been seen at least in Catania and Padova in the
past.
Seen (in Catania) first TIB module where gold layer on HV pad on
back is peeling away.
May drag away the bonds with it
Module will be declared faulty Repair center
Since Sep we see many TIB PA’s where bonds would stick with
unusually high parameters, or would not stick at all, in one or
more of these locations:
Pads 1-2, 27-30, 738-741, 767-768
Seen in: Bari, Catania, Padova.
Suspect bad PA metallization in those (symmetric!) spots
CMS Tracker Week - Module Production