Phase 1 FPIX mechanics status Phase 1 Pixel Upgrade Workshop - Aug2012 Plenary IV Session1 Kirk Arndt Purdue University for CMS FPIX Mechanical Group S. Kwan, C.M. Lei, S. Los, G. Derylo (Fermilab) G. Bolla, D. Bortoletto, I. Shipsey, Y. Ding, V. Noe-Kim, D. Snyder (Purdue)

4-Blade Thermal Test Setup 1st and 4th blades were glued to C-C rings with high-temperature thermally-conductive epoxy Duralco nd and 3rd blades were bonded with indium solder #1E (52%In 48%Sn). Duralco 132 epoxy was applied on all blade corners to reinforce the indium-bonded blade- to-rings joints. SS tubing was bonded within grooves in the C- C rings with Indalloy solder 121 (96.5%Sn 3.5%Ag) in the lower half and filled with thermal fillers in the upper half. RTDs were glued at points of interest. An IR Camera was used to measure the blade temperatures. SS tubing was connected to the Fermilab CO2 cooling system The whole assembly was installed inside an insulated enclosure which is cooled by CO2 and purged by dry nitrogen. Coolant inletCoolant outlet Blade #1 Inner C-C ring 2 Phase 1 Pixel Upgrade Workshop - Aug2012 Plenary IV Session

Blade 1Blade 2Blade 3Blade 4 4-Blade Test Results Temperature data at different module heating powers: 0, 1, 2 and 3 W per module Ambient n/a n/a n/a n/a Coolant inlet Coolant outlet Inner C-C ring Note: C-C rings and tubing temperatures measured by RTDs. Blade temperatures obtained from IR camera images. 3 Outer C-C ring Phase 1 Pixel Upgrade Workshop - Aug2012 Plenary IV Session

4 Blade temperatures (relative to the temperature measured on inlet tube) as a function of total power per blade Phase 1 Pixel Upgrade Workshop - Aug2012 Plenary IV Session

5 C-C ring temperatures (relative to the temperature measured on inlet tube) as a function of total power per blade Phase 1 Pixel Upgrade Workshop - Aug2012 Plenary IV Session

Conclusions from 4-Blade Test Blade and C-C ring temperatures varied in proportion to the module power – ∆T from center to ends of the blades was ~2.5 o C with 3W per module (6 W per blade) input power – ∆T from the inlet tube to the center of the blades was about: 22 o C on blade 3 (solder joints) 17 o C on blade 2 (solder joints) 17 o C on blade 1 (epoxy joints) 13 o C on blade 4 (epoxy joints) – ∆T from the inlet tube to the RTDs on the C-C rings was about: 4 to 6 o C on the outer ring 5 to 9 o C on the inner ring All Blade ∆T’s failed to meet the <10 o C design goal (which is actually <~8 o C between blades and cooling to allow for ~2 o C ∆T between modules and blades). The solder joints between blades and C-C rings performed poorly compared to the epoxy joints. The temperature rise of the C-C rings above the cooling inlet temperature was large. 6 Phase 1 Pixel Upgrade Workshop - Aug2012 Plenary IV Session

7 Post Mortem of Blade #3 Silver coating remained, never wetted. Silver coating never wetted by solder Once bonded with indium then coating detached because of surgery. Once bonded with solder then coating detached during surgery Finding: large voids existed between solder bonding surfaces, probably as a result of unmatched machined surfaces. Phase 1 Pixel Upgrade Workshop - Aug2012 Plenary IV Session

Alternative Blade Attachment Designs Option A: Slot with depth plus cf on both sides Option B: Slot with depth plus cf on 1 side Option C: Through slot plus cf on 1 side - Option A: 0.8 mm end surface only - Option B : 0.75 mm wall on 1 side mm end surface - Option C : 2 mm wall on 1 side only Abandon the elevated tab design, which required 2 perfectly matched machined surfaces Adopt a slot design which is easier to machine, solder, and increases contact area Solder required to be in contact with TPG directly The following 3 options are considered: Notes: After the solder joint is made, epoxy will be used between the cf & C-C for a better structural joint. The blade profile is different for the inner and outer assemblies. 8 Phase 1 Pixel Upgrade Workshop - Aug2012 Plenary IV Session

2 different shapes for blades needed Blade matched to outer assembly C-C rings shown here Identical blade does not match inner assembly C-C rings Phase 1 Pixel Upgrade Workshop - Aug2012 Plenary IV Session9

Choices of Solder SolderAvailable Form Joining Temp, C Tensile Strength, psi Lap shear, psi Thermal K, W/m-K CTE ppm/C 50 In 50 Sn0.030" wire/0.002" ribbon Bi 42 Sn0.030" wire only Sn 3.0Ag 0.5Cu0.030" wire/0.002" ribbon n/a 96.5Sn 3.5Ag0.030" wire/0.002" ribbon S " wire only220n/a500050n/a Solder in ribbon form can be placed in contact with the C-C part first. Blade is then inserted into the slot and brought into contact with the solder. Solder in the form of wire is applied after the blade is inserted, along the width of blade just outside the slot. Electrical heater or ultrasonic solder iron is then used to flow the solder to fill the gap. Flux may or may not be needed. Setup time for the production HD is long and flux can be boiled away, so it is preferred that no flux be used. Brazing Graphite–Carbon Bonding is available from a carbon-bonding vendor S-Bond Technologies. Joining with S-Bond requires a special high temperature/vacuum metallization done at SBT or under a special license. Thermal conductivity >50 W/m-K and shear strength >5000 psi is claimed.S-Bond Technologies After the S-Bond metallization is complete, any solder filler may be used to bond the graphite/carbon surfaces, provided it is fluxless and uses mechanical agitation to disrupt the solder’s oxide surfaces during assembly. This is an accessibility issue for production (i.e. can ultrasonically solder only 1 blade at a time). 10 Phase 1 Pixel Upgrade Workshop - Aug2012 Plenary IV Session

Next Steps Fabricate simple test samples with different blade attachments. Profile and dimensions are basically the same as those for production except with straight TPG edges on flat C-C pieces. Perform FEA to verify thermal and structural performances. Resume thermal tests including thermal cycles. Typical 1-Blade Sample (Option C as shown) 11 Phase 1 Pixel Upgrade Workshop - Aug2012 Plenary IV Session

Phase 1 FPIX Service Cylinder Concept for assembly of the cooling lines beyond the Half-Disks, DC-DC converters and POH/Portcards 12 3 Half Disks Port Cards and POH End Flange DC-DC converters Pipes and Cables CO2 cooling tubes and flex cables Phase 1 Pixel Upgrade Workshop - Aug2012 Plenary IV Session

13 Phase 1 Pixel Upgrade Workshop - Aug2012 Plenary IV Session

Supply Tubes between HDs and Portcards (blue) Return Tubes (white) 14 Phase 1 Pixel Upgrade Workshop - Aug2012 Plenary IV Session

DC-DC Converter Bus boards 15 Phase 1 Pixel Upgrade Workshop - Aug2012 Plenary IV Session

Supply Tubes for DC-DC Converters 16 Phase 1 Pixel Upgrade Workshop - Aug2012 Plenary IV Session

DC-DC Converter Mount Blocks 17 Phase 1 Pixel Upgrade Workshop - Aug2012 Plenary IV Session

DC-DC Converters 18 Phase 1 Pixel Upgrade Workshop - Aug2012 Plenary IV Session

POH / Portcard mount blocks (lower halves) 19 Phase 1 Pixel Upgrade Workshop - Aug2012 Plenary IV Session

Supply Tubes for POH / Portcards 20 Phase 1 Pixel Upgrade Workshop - Aug2012 Plenary IV Session

POH / Portcard mount blocks (upper halves) 21 Phase 1 Pixel Upgrade Workshop - Aug2012 Plenary IV Session

POH (3 per port card) on mount blocks 22 Phase 1 Pixel Upgrade Workshop - Aug2012 Plenary IV Session

POH and Portcards 23 Phase 1 Pixel Upgrade Workshop - Aug2012 Plenary IV Session

Single Portcards with 14 module readout flex cables per portcard 24 Phase 1 Pixel Upgrade Workshop - Aug2012 Plenary IV Session

Double-stacked Portcards (2 POH per port card) with with 7 module readout flex cables per portcard 25 1 st tier Phase 1 Pixel Upgrade Workshop - Aug2012 Plenary IV Session

Double-stacked Portcards (2 POH per port card) 26 2 nd tier Phase 1 Pixel Upgrade Workshop - Aug2012 Plenary IV Session

Flex cables attachment to the port cards still to be done. Some cable slots on the forward section need to be relocated slightly. For the first installation, it seems doable and easier to install in this order 1 st outer, 1 st inner, 2 nd outer, 2 nd inner, 3 rd outer and 3 rd inner. Notes: Mock-up of phase 1 service cylinder Dummy flex cables outside cylinder 27 Some interference of this cable with the spoke Cable slots to be relocated to reduce cable interference with the spokes Phase 1 Pixel Upgrade Workshop - Aug2012 Plenary IV Session

Backup slides 28 Phase 1 Pixel Upgrade Workshop - Aug2012 Plenary IV Session

1-Feb-12Phase 1 FPix Cooling & Mechanics Update29 3 joint samples consisting of cf encapsulated TPG & CC were successfully made – 2 samples made on coatings of Ni + Ag – 1 sample made on coatings of Al + Ti + Ni + Ag Reasonable joint strength observed Thermal testing was conducted on first 2 samples Indium Bonding R&D Status Weight of steel ruler & al block ~ 235 g

X-Ray for TPG sample through CC base New Joint Samples Made and Inspection Coating recipe: 5 micron Nickel + 1 micron Silver - 1 sample between cf encapsulated TPG and CC - 1 sample between ss tubing and CC - all samples appear to have good joint strength Cut-section Check 30USCMS Collaboration Meeting18 May 2012

Sample OptionAAABCCCD Large end C-C0.75mm dp slot thru' slot 0.75mm dp slot Large blade endcf on both sides cf on 1 side Small end C-C0.75mm deep slot thru' slot 0.75mm deep slot Small blade endcf on both sides cf on 1 side TPG L end t, mm Slot width, mm1.04 solder t, mm0.1 glue t, mm Blade installation slide in through open- end slot engage L end C-C first; move in S end C- C with tooling slide in radial inwards thru' L end C-C; push TPG sideway in contact with indium; fill up the gap with epoxy; slide in radial inwards thru' L end C-C; push TPG sideway in contact with indium; fill up the gap with epoxy; slide in radial inwards thru' L end C-C; keep 0.004" gap btw TPG & C-C wall; fill up the gap with epoxy; slide in radial inwards thru' L end C-C; keep 0.004" gap btw TPG & C-C wall; fill up the gap with epoxy; slide in through open- end slot coatingNi + Cu S-BondNi + Cu S-Bond solder application place 0.76mm 96.5Sn, 3.5 Ag wire beyond the groove after blade installation place 0.1mm 96.5Sn, 3.5 Ag ribbon before blade installation place 1.6 mm S-200 wire after blade installation place 0.76mm 96.5Sn, 3.5 Ag wire after blade installation place 1.6 mm S-200 wire after blade installation Post work add epoxy btw C-C & cf Remarks "capillary" with flux, may not cook the whole HD in 1 step because flux may boil off if too long time for setting up. cook smaller HD sub- assemblies Need something extra to support the L end C-C ring for installation; can cook whole HD; largest contact area btw indium & C-C; Need something extra to support the L end C-C ring for installation; can cook whole HD; largest contact area btw indium & C-C; Need something extra to support the L end C-C ring for installation; can cook whole HD; largest contact area btw indium & C-C; can only bond 1 blade at 1 time, laborious. Need something extra to support the L end C-C ring for installation; can cook whole HD; largest contact area btw indium & C-C; can only bond 1 blade at 1 time, laborious. can only bond 1 blade at 1 time, laborious. with or without flux if ribbon works, S- bond coating is another option no diff btw B & C, same cons for installation, thermal performance, machining $ may be higher, no ooze out for blind slot.all vendor's work. make sample?no gogo.go?debatablegogo, make 2?no go. Blade-ring attachment Options 31 Phase 1 Pixel Upgrade Workshop - Aug2012 Plenary IV Session

FEA of Temperatures with Different Blade Attachments Simplified rectangular blade; same overall thickness with 0.68 mm TPG plus 0.06 mm cf facings; eqv. blade area half model: 39.5 mm x 30.4 mm x 0.8 mm heat input for half model: 3W heat sink temperature on ‘exposed’ TPG = 0 o C - Option A : 0.8 mm end surface only - Option B : 0.75 mm wall on 1 side mm end surface - Option C : 2 mm wall on 1 side only 32 Phase 1 Pixel Upgrade Workshop - Aug2012 Plenary IV Session

ResultsMax temp drop% Reduction Option A2.1291% Option B2.1091% Option C % Option AOption COption B Conclusion: End surface contact with TPG generates less temperature drop, but amount is not significant. Blade solder attachment location should not be a deciding factor. 33 Phase 1 Pixel Upgrade Workshop - Aug2012 Plenary IV Session

50um gapssolder C-C TPG epoxy Blade-Ring S-Bond design option Phase 1 Pixel Upgrade Workshop - Aug2012 Plenary IV Session34

Boundary conditions: -30C fixed temperature in C-C cooling grooves No heat from modules (so entire assembly is the same -30C temperature) C-C rings, TPG blades, Si modules material properties TPG blades bonded to C-C rings (no separation or slippage allowed) Si modules allowed to slip on, but not separate from, surfaces of the blades 35 Phase 1 Pixel Upgrade Workshop - Aug2012 Plenary IV Session

Boundary conditions same as previous slide, but with 3W power generated in each Si module  Negligible change in overall stress with modules powered on or off  Most of the thermal stress results from the difference in CTE between C-C and TPG 36 Phase 1 Pixel Upgrade Workshop - Aug2012 Plenary IV Session

Engineering data used for this structural analysis C-C rings: Isotropic Instantaneous Coefficient of Thermal Expansion4E-06 C^-1 Isotropic Elasticity Derive from Bulk Modulus and Young's Modulus Young's Modulus95000MPa Poisson's Ratio0.318Pa Bulk Modulus87000MPa Shear Modulus36039MPa Isotropic Thermal Conductivity200W m^-1 C^-1 TPG blades: Orthotropic Instantaneous Coefficient of Thermal Expansion Coefficient of Thermal Expansion X direction5E-07C^-1 Coefficient of Thermal Expansion Y direction5E-07C^-1 Coefficient of Thermal Expansion Z direction6.5E-06C^-1 Isotropic Elasticity Derive from Bulk Modulus and Young's Modulus Young's Modulus20000MPa Poisson's Ratio0.467Pa Bulk Modulus100000MPa Shear Modulus6818MPa Orthotropic Thermal Conductivity Thermal Conductivity X direction400W m^-1 C^-1 Thermal Conductivity Y direction400W m^-1 C^-1 Thermal Conductivity Z direction3.5W m^-1 C^-1 Silicon modules: Isotropic Instantaneous Coefficient of Thermal Expansion2.49E-06C^-1 Isotropic Elasticity Derive from Bulk Modulus and Shear Modulus Young's Modulus114701MPa Poisson's Ratio0.306Pa Bulk Modulus98740MPa Shear Modulus43900MPa Isotropic Thermal Conductivity124W m^-1 C^-1 37 Phase 1 Pixel Upgrade Workshop - Aug2012 Plenary IV Session

The tensile strength of #1E In solder is 1720psi = 11.8 MPa  This is 72% of the maximum stress in the blade/ring joints from the FEA In solder properties Araldite 2011 epoxy cured properties The tensile strength of Araldite 2011 is 4800psi = 33 MPa  This is 200% of the maximum stress in the blade/ring joints  S-Bond claims their “active” solder joints between carbon materials are “strong” (>5000psi), see Phase 1 Pixel Upgrade Workshop - Aug2012 Plenary IV Session

Removable Coupling Status (laser welded to 1.6mm OD tubing) Successfully held hydrostatic pressure up to 4,000 psi (276 bar) Safety factor >2.5 based on design pressure = 110 bar (EU standards require testing with safety factor x1.43 = 157 bar) Existing coupler design can be modified for larger tubing weldment for supply and return tubes. Male plug hole ID can be machined for larger tube and welding 39 Phase 1 Pixel Upgrade Workshop - Aug2012 Plenary IV Session