phase 1 fpix mechanics status phase 1 pixel upgrade workshop - aug2012 plenary iv session1 kirk...

Plenary IV Session 1

Phase 1 FPIX mechanics status

Phase 1 Pixel Upgrade Workshop - Aug2012

Kirk ArndtPurdue University

for CMS FPIX Mechanical GroupS. 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 132.

• 2nd 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 #1Inner C-C ring



-14.1-11.2-9.0

-7.9-11.1

Blade 1 Blade 2 Blade 3 Blade 4

4-Blade Test ResultsTemperature data at different module heating powers: 0, 1, 2 and 3 W per module

-15.2

Ambient

3.2

0 -19.31 -12.32 -8.13 -4.5

0 -17.41 -12.42 -7.33 -3.2

0 n/a1 n/a2 n/a3 n/a

3.2

0 -18.31 -9.92 -2.03 +5.5

0 -17.71 -9.22 -1.83 +5.7


3.2

0 -19.01 -12.02 -5.73 +0.4

0 -18.11 -11.82 -4.73 +0.8

0 n/a1 n/a2 -7.73 -2.1

3.2

0 -19.01 -12.02 -5.63 +0.8

0 -17.31 -10.62 -4.53 +1.4


0 -18.01 -18.02 -17.93 -17.7

0 -15.61 -14.22 -12.93 -11.7

0 -14.41 -11.62 -9.13 -6.8

0 -14.71 -12.82 -11.23 -9.9

0 -5.11 -4.82 -4.23 -3.9

0 -16.21 -14.92 -13.73 -12.7

0 -16.61 -16.52 -16.33 -16.3

Coolant inlet

Coolant outletInner C-C ring

Note: C-C rings and tubing temperatures measured by RTDs. Blade temperatures obtained from IR camera images.

Outer C-C ring



Blade temperatures (relative to the temperature measured on inlet tube) as a function of total power per blade



C-C ring temperatures (relative to the temperature measured on inlet tube) as a function of total power per blade



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 ~2.5oC with 3W per module (6 W per blade) input power

– ∆T from the inlet tube to the center of the blades was about:• 22oC on blade 3 (solder joints)

• 17oC on blade 2 (solder joints)

• 17oC on blade 1 (epoxy joints)

• 13oC on blade 4 (epoxy joints)

– ∆T from the inlet tube to the RTDs on the C-C rings was about:• 4 to 6oC on the outer ring

• 5 to 9oC on the inner ring

• All Blade ∆T’s failed to meet the <10oC design goal (which is actually <~8oC between blades and cooling to allow for ~2oC ∆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.



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


Alternative Blade Attachment Designs

Option A: Slot with depthplus

cf on both sides

Option B: Slot with depthplus

cf on 1 side

Option C: Through slotplus

cf on 1 side

- Option A: 0.8 mm end surface only - Option B : 0.75 mm wall on 1 side + 0.74 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.



• 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



Choices of Solder

Solder Available FormJoining 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 140 1720 1630 34 2058 Bi 42 Sn 0.030" wire only 160 8000 500 19 15

96.5Sn 3.0Ag 0.5Cu 0.030" wire/0.002"

ribbon 250 7200 n/a n/a n/a

96.5Sn 3.5Ag 0.030" wire/0.002"

ribbon 250 5800 2700 33 30S-200 0.063" wire only 220 n/a 5000 50 n/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.

• 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).


http://www.s-bond.com/


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)



Phase 1 FPIX Service CylinderConcept for assembly of the cooling lines beyond the Half-Disks,

DC-DC converters and POH/Portcards

3 Half Disks

Port Cards and POH

End Flange

DC-DC converters

Pipes and Cables

CO2 cooling tubes and flex cables


Plenary IV Session 13Phase 1 Pixel Upgrade Workshop - Aug2012


Supply Tubes between HDs and Portcards (blue)Return Tubes (white)



DC-DC Converter Bus boards



Supply Tubes for DC-DC Converters



DC-DC Converter Mount Blocks



DC-DC Converters



POH / Portcard mount blocks (lower halves)



Supply Tubes for POH / Portcards



POH / Portcard mount blocks (upper halves)



POH (3 per port card) on mount blocks



POH and Portcards



Single Portcards with 14 module readout flex cables per portcard



Double-stacked Portcards (2 POH per port card) withwith 7 module readout flex cables per portcard

1st tier



Double-stacked Portcards (2 POH per port card)

2nd tier



• 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

1st outer, 1st inner, 2nd outer, 2nd inner, 3rd outer and 3rd inner.

Notes:

Mock-up of phase 1 service cylinder

Dummy flex cables outside cylinder

Some interference of this cable with the spoke

Cable slots to be relocated to reduce cable

interference with the spokes



Backup slides


Phase 1 FPix Cooling & Mechanics Update 291-Feb-12

• 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

USCMS Collaboration Meeting 30

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

18 May 2012


Sample Option A A A B C C C D

Large end C-C 0.75mm dp slot 0.75mm dp slot 0.75mm dp slot thru' slot thru' slot thru' slot thru' slot 0.75mm dp slotLarge blade end cf on both sides cf on both sides cf on both sides cf on 1 side cf on 1 side cf on 1 side cf on 1 side cf on 1 side

Small end C-C 0.75mm deep slot 0.75mm deep slot 0.75mm deep slot 0.75mm deep slot thru' slot thru' slot thru' slot 0.75mm deep slot Small blade end cf on both sides cf on both sides cf on both sides cf on both sides cf on 1 side cf on 1 side cf on 1 side cf on 1 side

TPG L end t, mm 0.8 0.8 0.8 0.74 0.74 0.74 0.74 0.74Slot width, mm 1.04 1.04 1.04 1.04 1.04 1.04 1.04 1.04

solder t, mm 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1glue t, mm 0.14 0.14 0.2 0.2 0.2 0.2 0.2

Blade installation

slide in through open-end slot

engage L end C-C first; move in S end C-C

with tooling

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;


push TPG sideway in contact with indium; fill up the gap with

epoxy;


keep 0.004" gap btw TPG & C-C wall; fill up the gap with epoxy;


keep 0.004" gap btw TPG & C-C wall; fill up the gap with epoxy;

slide in through open-end slot

coating Ni + Cu Ni + Cu S-Bond Ni + Cu Ni + Cu S-Bond S-Bond 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 add epoxy btw C-C &


cfadd 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-

assembliescook 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;



whole HD; largest contact area btw

indium & C-C;



whole HD; largest contact area btw indium & C-C; can

only bond 1 blade at 1 time, laborious.



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 go go. go? debatable go go, make 2? no go. no go.

Blade-ring attachment Options



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 = 0oC - Option A : 0.8 mm end surface only - Option B : 0.75 mm wall on 1 side + 0.74 mm end surface - Option C : 2 mm wall on 1 side only



Results Max temp drop % ReductionOption A 2.12 91%Option B 2.10 91%Option C 2.32 100%

Option A Option 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.Phase 1 Pixel Upgrade

Workshop - Aug2012


50um gaps solder

C-C

TPGepoxy epoxy

Blade-Ring S-Bond design option



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



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



Engineering data used for this structural analysisC-C rings:Isotropic Instantaneous Coefficient of Thermal Expansion 4E-06 C^-1Isotropic Elasticity Derive from Bulk Modulus and Young's Modulus

Young's Modulus 95000 MPaPoisson's Ratio 0.318 PaBulk Modulus 87000 MPaShear Modulus 36039 MPa

Isotropic Thermal Conductivity 200 W m^-1 C^-1

TPG blades:Orthotropic Instantaneous Coefficient of Thermal Expansion

Coefficient of Thermal Expansion X direction 5E-07 C^-1Coefficient of Thermal Expansion Y direction 5E-07 C^-1Coefficient of Thermal Expansion Z direction 6.5E-06 C^-1

Isotropic Elasticity Derive from Bulk Modulus and Young's ModulusYoung's Modulus 20000 MPaPoisson's Ratio 0.467 PaBulk Modulus 100000 MPaShear Modulus 6818 MPa

Orthotropic Thermal ConductivityThermal Conductivity X direction 400 W m^-1 C^-1Thermal Conductivity Y direction 400 W m^-1 C^-1Thermal Conductivity Z direction 3.5 W m^-1 C^-1

Silicon modules:Isotropic Instantaneous Coefficient of Thermal Expansion 2.49E-06 C^-1Isotropic Elasticity Derive from Bulk Modulus and Shear Modulus

Young's Modulus 114701 MPaPoisson's Ratio 0.306 PaBulk Modulus 98740 MPaShear Modulus 43900 MPa

Isotropic Thermal Conductivity 124 W m^-1 C^-1



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 http://www.s-bond.com/cms/files/file_ID53422.pdf


http://www.s-bond.com/cms/files/file_ID53422.pdf


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 weldingPhase 1 Pixel Upgrade Workshop - Aug2012

phase 1 fpix mechanics status phase 1 pixel upgrade workshop - aug2012 plenary iv session1 kirk...

Documents

cc rings

blade testblade

blade corners

inner cc ring2phase

outer cc ringphase

indiumbonded blade

blade input power t

blade thermal test setup1st