CMS Tracker Week, CERN, Oct Oct 2005CMS Tracker Week - Module ProductionSalvatore Costa - Catania Report from Module Bonding Working Group Salvatore Costa Università di Catania and INFN – Sezione di Catania

26 Oct 2005CMS Tracker Week - Module Production2 Salvatore Costa - Catania Outline 1.Pull Test results 2.Open issues 3.Some peculiar failures

CMS Tracker Week, CERN, Oct Oct 2005CMS Tracker Week - Module ProductionSalvatore Costa - Catania Global review of Module bonding quality that is, Module Pull Test results

26 Oct 2005CMS Tracker Week - Module Production4 Salvatore Costa - Catania # Modules Pull Tested

26 Oct 2005CMS Tracker Week - Module Production5 Salvatore Costa - Catania Mean pull forces

26 Oct 2005CMS Tracker Week - Module Production6 Salvatore Costa - Catania Mean pull forces

26 Oct 2005CMS Tracker Week - Module Production7 Salvatore Costa - Catania StDev/Mean of pull forces

26 Oct 2005CMS Tracker Week - Module Production8 Salvatore Costa - Catania StDev/Mean of pull forces

CMS Tracker Week, CERN, Oct Oct 2005CMS Tracker Week - Module ProductionSalvatore Costa - Catania Open issues

CMS Tracker Week, CERN, Oct Oct 2005CMS Tracker Week - Module ProductionSalvatore Costa - Catania TEC Backplane HV Connection A Bonding and Gantry joined operation 1.Review of established practices in EU and US 2.Preparation for it in Italy

26 Oct 2005CMS Tracker Week - Module Production11 Salvatore Costa - Catania TEC Backplane HV Connection New DB Interface with new section –v. 6.0 –v. 6.0_US

26 Oct 2005CMS Tracker Week - Module Production12 Salvatore Costa - Catania HV Connection types Connection type inventory: 1.Conductive Glue dots between gold pad and Sensor (at Gantry) 2.Conductive Glue reinforcement over gold pad and Sensor (normally at Gantry, occasionally at Bonding) 3.Bonds without encapsulation (at Bonding) 4.Bonds with encapsulation (at Bonding) Current established practice: EU: US: [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.

Slide 13Susanne KyreTracker week, October 2005 Material and Preparation Sylgard 186 Silicone Elastomer, 2 part kit, 10:1 mixing ratio (manufacturer: Dow-Corning) Mixing cups Mixing sticks Digital bench scale Small vacuum chamber or centrifuge for degassing

Slide 14Susanne KyreTracker week, October 2005 Dispensing Equipment Pneumatic glue dispenser with foot pedal and timed pulse option (manufacturer: EFD model: Ultra 1400) 3ccm syringe barrel and piston (EFD) Smooth-flow tapered tips, gage 20 (EFD)

Slide 15Susanne KyreTracker week, October 2005 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 16Susanne KyreTracker week, October 2005 Procedure I 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

Slide 17Susanne KyreTracker week, October 2005 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

Slide 18Susanne KyreTracker week, October 2005 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

26 Oct 2005CMS Tracker Week - Module Production19 Salvatore Costa - Catania Established EU procedure 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

26 Oct 2005CMS Tracker Week - Module Production20 Salvatore Costa - Catania …Except for R4S modules… …because:

26 Oct 2005CMS Tracker Week - Module Production21 Salvatore Costa - Catania

26 Oct 2005CMS Tracker Week - Module Production22 Salvatore Costa - Catania

26 Oct 2005CMS Tracker Week - Module Production23 Salvatore Costa - Catania

26 Oct 2005CMS Tracker Week - Module Production24 Salvatore Costa - Catania 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 supported  No 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.

26 Oct 2005CMS Tracker Week - Module Production25 Salvatore Costa - Catania 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

CMS Tracker Week, CERN, Oct Oct 2005CMS Tracker Week - Module ProductionSalvatore Costa - Catania Some peculiar Module failures

26 Oct 2005CMS Tracker Week - Module Production27 Salvatore Costa - Catania Some recent peculiar Module failures 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, , –Seen in: Bari, Catania, Padova. –Suspect bad PA metallization in those (symmetric!) spots