Tracker Upgrade Workshop - June 3, 2009

1K. Arndt - Purdue

Phase 1 FPix Mechanics Plans for module assembly

Phase 1 design objectives:1. Reduce # of module types and interfaces 2. Integrate CO2 cooling and lightweight support3. Improve cooling and cable routing and move the control

electronics to high η 4. Improve the geometry to maximize 4 pixel hit η range

Kirk ArndtPurdue University

K. Arndt - Purdue Tracker Upgrade Workshop - June 3, 2009

22

Phase 1 Mechanics R&D tasks at Purdue

• Continue study of module, cooling tube and electronics layout with

FNAL to optimize mechanical design

• Identify candidate adhesives/thermal interface materials and test

radiation effects

• Begin integration of optics, vacuum, and glue dispensing to motion

control system for semi-automated module assembly

• Assemble mechanical grade module prototypes to evaluate

adhesives, interconnects, and develop assembly tooling and

procedure

K. Arndt - Purdue Tracker Upgrade Workshop - June 3, 2009

33

Module development - Adhesives study

• Requirements for adhesive:– Thermal conductivity: > 0.2 W/m-K

– Soft: shear modulus < 50 N/mm^2

– Conformable to 50 micron non-flatness

– Radiation hard

– Electrically non-conductive

– Curing at room temperature

– Not flowing during application: adhesive confined within chip

– Good wetting properties

– Not creeping after curing

– Allow integrated module replacement without damaging the support

• Status– Begun a market survey of adhesives for pixel integrated module

assembly with potential to meet requirements for SLHC (including adhesives used in current LHC detectors – ALICE, ATLAS, CMS, LHCb and TOTEM)

– 6 primary candidate adhesives selected for further testing so far

– Building mechanical grade samples using candidate adhesives for evaluation of mechanical properties before and after irradiation

FPIX adhesive sample for tensile testing after

irradiation

K. Arndt - Purdue Tracker Upgrade Workshop - June 3, 2009

44

Radiation resistance of adhesives

• Extensive work has been carried out on radiation effects in polymers, mainly for nuclear reactor applications and radiation processing.

• Radiation damage studies of organic materials (at CERN in the 1990’s) produced the table above with approximate radiation levels up to which category adhesives can be used.

• The relative radiation resistance of a number of different materials indicates that high temperature resins are extraordinarily resistant to radiation.

• The adhesive-substrate interface (composed of ionic and physical bonds) is not usually sensitive to radiation – typically no degradation is observed until the polymer itself (covalent bonds) degraded.

• This is a general guideline - environmental conditions such as temperature, humidity, and dose rate, as well as additives influence the radiation behavior of materials.

10 yrs LHC

10 yrs SLHC

K. Arndt - Purdue Tracker Upgrade Workshop - June 3, 2009

55

Mechanical tests of adhesives

• Two types of mechanical tests are planned:– shear tests on lap-joint samples with symmetric single lap

geometry (shown above)– peel tests on adhesive tapes

• Lap-joint samples are made with aluminum or fiberglass reinforced epoxy

• thickness is controlled in order to obtain 100 +/-30 micron thick adhesive layers

• Adhesive tapes are assessed by means of peel tests: the tapes are glued to an aluminum plate

• Shear or peel strength will be measured using an Instron machine

K. Arndt - Purdue Tracker Upgrade Workshop - June 3, 2009

66

Automated module assembly

• Will use robotic ‘pick-and-place’ machine with optics and glue dispensing for upgrade module assembly

• Could also be used for module placement on upgrade panels

• Robotics will help in almost any large scale Inner Detector upgrade scenario

• Smaller ‘standing army’, shorter production time

• Leads to uniformity of production techniques

Status– Installed and programmed new encapsulation

dispensing robot (pictured left)– Gantry Positioning System ordered (shown above),

delivery expected late Summer 2009– Will integrate optics, pattern recognition software,

vacuum pick-up tool and glue dispensing to the motion control system

– Lots of code development, process development, and prototyping before production module assembly begins

K. Arndt - Purdue Tracker Upgrade Workshop - June 3, 2009

77

Mechanical grade module prototypes

Status– Three options for module “stack-ups” BPIX modules (HDI with TBM on top of the

module) probably easier to assemble and test (option A)– Obtaining materials and tooling for prototype module assembly– Once a baseline conceptual design for modules is set for FPIX, we will assemble

mechanical grade module prototypes to evaluate adhesives, interconnects, and develop assembly tooling and procedure

K. Arndt - Purdue Tracker Upgrade Workshop - June 3, 2009

8

Possible Blade Readout (option B)

• Use two separate readout loops for each 2x8 module, and to send a combined stream to a single electro-optical driver

• One TBM reads out two 2x8 Modules and sent upstream by one optohybrid channel and readout by one FED channel

• Output data is sent to a “Port Card” via a flex cable, similar to the existing extension cable

• Flex Cable length should be 50-60 cm and has a connector or is permanently attached to the HDI; it will have a right angle bend

• Flex Cable carries Bias voltage, Power voltages, and all controls and data signals

• Estimates show the existing Extension Cable has a 3db/m attenuation at 320 MHz, sufficient for digital data transmission; confirmed recently in a bench test

• CONS: HDI is a thermal barrier, commit two modules for every HDI

Fold

lin

e

2x8 2x8

Port Card

TBM

320

MH

z

K. Arndt - Purdue Tracker Upgrade Workshop - June 3, 2009

9

Integrated Module/Panel Concept

• ROCs mounted directly on high heat transfer/stiff material (ex. Thermal Pyrolytic Graphite)

• Wirebond connections from ROCs to HDI through slots in rigid panel/heat spreader (TPG)

• Connects two modules to a single TBM AND avoids locating HDI between ROCs and TPG heat spreaders (i.e. thermal path to edge cooling)

• Leaves pixel sensor uncovered for scanning with pulsed laser

• Flip chip module REMOVABLE, leaving bus structure (HDI) intact for replacement module

2x8 BBM

TBM TPGHDI

2x8 BBM

TPG

HDI pigtail

K. Arndt - Purdue Tracker Upgrade Workshop - June 3, 2009

10

Integrated Modules in half-disk with “edge cooling”

Each Panel has a single readout/power cable that exits the half-disk on side

away from the IP = simple cable routing

CO2 flow

CO2 flow

Heat flow

• Heat flows radially from ROCs through TPG substrates to outer and inner rings with CO2 cooling

• Heat flow is not interrupted by slots in substrates for wirebonds

Heat flow

K. Arndt - Purdue Tracker Upgrade Workshop - June 3, 2009

11

Integrated Module assembly

1. HDI and standoff rails glued to TPG substrates2. TBM mounted and wirebonded to HDI3. Assembly flipped over4. 2x8 modules mounted on TPG substrates5. Wirebond connections from modules to HDI through slots in TPG substrates

TBM on backside of HDI

Standoff rails

K. Arndt - Purdue Tracker Upgrade Workshop - June 3, 2009

12

Alternative Integrated Module assembly

1. HDI glued and standoff rails glued to TPG substrates2. Assembly flipped over3. TBM mounted and wirebonded to HDI4. 2x8 modules mounted on TPG substrates5. Wirebond connections from modules to HDI through slots in TPG substrates

TBM “on top” of HDI, access through cutout

in TPG substrate

K. Arndt - Purdue Tracker Upgrade Workshop - June 3, 2009

1313

Time scale and Milestones for Phase 1 Mechanics R&D

• Module and disk conceptual design and studies are ongoing baseline conceptual mechanical and electrical design this Summer.

• Small prototype development for testing will follow.

• Goal to build full-scale prototypes for thermal and mechanical tests in early 2010.

Note: Time scale for Phase I TDR (Spring 2010)

K. Arndt - Purdue Tracker Upgrade Workshop - June 3, 2009

14

Credits

This work is part of our R&D plan described in:

Proposal for US CMS Pixel Mechanics R&D

at Purdue and Fermilab Daniela Bortoletto, Petra Merkel, Ian Shipsey, Kirk Arndt, Gino Bolla, Simon Kwan, Joe Howell, C.M. Lei, Rich Schmitt, Terry Tope, J. C. Yun with valuable input from

Lucien Cremaldi, Greg Derylo, Mikhail Kubantsev, Vesna Cuplov (http://indico.cern.ch/conferenceDisplay.py?confId=28746)

Tracker Upgrade Workshop - June 3, 2009

Backup slides

K. Arndt - Purdue

15

K. Arndt - Purdue Tracker Upgrade Workshop - June 3, 2009

1616

Summary - Mechanics R&D status at Purdue

Action item Status

Continue study of module, cooling tube and electronics layout with FNAL to optimize mechanical design

BPIX/FPIX envelope defined.Determining optimal segmentation of readout chain.Moving from design alternatives to a baseline conceptual mechanical and electrical design.

Test candidate adhesives/thermal interface materials

Completing market survey.Candidate adhesives identified.Begun building mechanical test samples.Evaluation of properties after irradiation will follow.

Begin integration of optics, vacuum, and glue dispensing to motion control system for semi-automated module assembly

Gantry Positioning System ordered, delivery in ~3 months.Beginning purchase and integration of optics, pattern recognition software, vacuum pick-up tool and glue dispensing to the motion control system.

Prepare to assemble mechanical grade module prototypes to evaluate adhesives, interconnects, and develop assembly tooling and procedure

Identified three module “stack-up” options.Obtaining materials and tooling for prototype module assembly.Purchased and installed new glue and encapsulation dispensing robot.Will assemble mechanical grade module prototypes to evaluate adhesives, interconnects, and develop assembly tooling and procedure (once baseline design is set).

K. Arndt - Purdue Tracker Upgrade Workshop - June 3, 2009

1717

Mechanical Design optimization status

• Defined Phase 1 BPIX and FPIX envelopes• Converging on radial layout of 2x8 modules-in-half disk geometry for FPIX to

maximize coverage with 4-layer BPIX design proposal• New FPIX geometries studied using simulation Rotated Vane geometry

preserves (or slightly improves) resolution while Fresnel Lens and Inverted Cone performs worse than the current turbine blade geometry

• Determining constraints on the readout chain in order to optimize the segmentation and layout of 2x8 modules in half-disks

• Once the readout segmentation is defined, we will move from design alternatives to a baseline conceptual mechanical and electrical design.

2x8 modules in Rotated Vane

geometry

Current BPIX/FPIX envelope definition

18

Phase 1 FPIX Disk layout requirements

1. Fits within Phase 1 FPIX envelope definition2. Modules oriented radially (requires only 2x8 modules, and slightly improves

resolution)3. Locates all outer radius sensors as far forward and out in radius as possible

(to minimize the gap in 4-hit coverage between the end of the 4th-barrel layer and the forward-most disk)

4. Maximize 4-hit coverage between end of 4th layer barrel up to eta = 2.5, for particles originating at the IP +/-5cm, using a minimum number of modules

5. Individual modules and/or module-support substrates removable and replaceable without disassembling disks

6. One (or at most 2) geometry substrate(s) to support modules7. Two (or all three) disks on each side of the I.P. identical8. Minimizes the amount of material required for cooling and module support,

where module location is repeatable and stable to <10 microns with thermal cycling and background vibrations

9. Readout requires no more than (estimated) 700 available AOH.10. Uses identical (or at most two) geometries of HDI/pigtail cables.11. (Highly desirable) Delta T < 5C across a single module12. (Desirable) Separate inner from outer rings for easier replacement of

individual modules (and inner radius Vanes with earlier radiation damaged modules)

K. Arndt - Purdue FPix Upgrade Meeting - May 2009

19

Current Phase 1 BPIX / FPIX envelope definition

20

Current FPix module layout

7 module geometries

168 modules per disk(1080 ROCs per disk)

Radial layout of (68 or 72) 2x8 outer and (44 or 48) 2x8 inner radius modules

1 module geometry116 or 120 modules per disk

(1856 or 1920 ROCs per disk)

R 144.6 mm

R 58.7 mm

R ~160 mm

R ~40 mm

Conceptual Disk Module Layout radial and overlaps (with 20° tilt of sensors) to cover Phase 1 FPIX region

K. Arndt - Purdue FPix Upgrade Meeting - May 2009

21

½-Disks using 2x8 modules on identical rotated “Vanes”for 6-disk system

• All identical 2x8 modules on identical Vanes

• One module on each side of 18 outer and 12 inner Vanes (and 14 in intermediate radius 3rd Disk option)

front back

Full ½-Disks

reduced 3rd ½-Disk option

Note: More z-axis separation between neighboring Vanes needed to avoid interference at inner radius

2x8 active sensor areas shown in red

K. Arndt - Purdue FPix Upgrade Meeting - May 2009

22

Current FPIX Half-Disk

Minimum separation between neighboring blades is 5mm

5mm gap

K. Arndt - Purdue FPix Upgrade Meeting - May 2009

23

2x8 modules on Rotated Vanes

Require sufficient clearance to allow for removal and replacement of individual Vanes without having to take an entire half-disk apart

More z-axis separation needed between neighboring Vanes to avoid interference at inner ends

Three sets of (six) Vanes with 5mm minimum separation between neighboring Vanes

291396

All Identical disks (1st and 2nd disks in locations to maximize 4-hit eta coverage)6 disks = (6x72) outer + (6x48) inner = 720 2x8 modules (11520 ROCs)

Note: distance units in mmcurrent FPIX 4 disks at Z: ±355 and ±485 mm

η = 1.3 η = 1.6

η = 2.1

η = 2.5

2x8s

2x8s

2x8s

2x8s 2x8s

2x8s

Z loc. TBD suggest 491mm from IP

30

60

161

45

64.8

K. Arndt - Purdue FPix Upgrade Meeting - May 2009

25

Identical 1st and 2nd disks, different 3rd disk to reduce number of modules and material6 disks = (4x72) outer + (4x48) inner + (2x56) middle = 592 2x8 modules (9472 ROCs)

291396

η = 1.3 η = 1.6

η = 2.1

η = 2.5

461

2x8s

2x8s

2x8s

2x8s

2x8s

K. Arndt - Purdue FPix Upgrade Meeting - May 2009

26

All 2x8 modules on identical Vanes

• Identical 1st and 2nd ½-disks, and intermediate radius 3rd ½-disks, shown in current service cylinder 

• This scheme uses identical modules on identical Vanes, and is potentially the lowest material solution for a 6-disk system.

• Identical 1st, 2nd and 3rd ½-disks may be preferable.

K. Arndt - Purdue FPix Upgrade Meeting - May 2009

27

Conceptual Readout chain unit = “Vane”

One TBM per 2x8 module on each side of the Vane = 2 TBM channels + 2 AOH per Vane

• A single TBM + one AOH channel per 2x8 module (16 ROCs) • Two 2x8s modules per Vane (one module on each side)• Could use the same module as BPix

K. Arndt - Purdue FPix Upgrade Meeting - May 2009

28

Vanes cooled from edges (Rings)Consider CO2 cooling tubes in outer and inner rings to cool

edges of vanes with pixel modules mounted on heat spreaders

CO2 flow

in

CO2 flow out

Heat flow

K. Arndt - Purdue FPix Upgrade Meeting - May 2009

29

Study of New FPix Geometries

150um global radius direction 100um

global phi

directi

on

• Radial layouts of modules (using the Phase 1 PSI ROC) align the 150 micron dimension of each pixel in the radius direction and the 100 micron dimension in the phi direction.

• 2x8 module layout with 20° or 30° tilt to the Z-axis

• modules aligned radially and castellated on conical 'disks'

• New proposed FPix geometries were studied by Morris Swartz (JHU) using the detailed Pixelav simulation that is used to generate our reconstruction templates.

• Four geometries were studied: the current design, the Rotated Vane, and 20° and 30° ‘Fresnel’ options pictured below…

K. Arndt - Purdue FPix Upgrade Meeting - May 2009

30

FPix Geometry RMS Res x RMS Res y RMS Res rRMS Res

phi

Current Geometry 8.4 mm 18.9 mm 8.4 mm 17.8 mm

Rotated Vane (20°)

13.5 mm 8.1 mm 13.5 mm 7.6 mm

Fresnel (20°) 39.4 mm 16.6 mm 37.0 mm 16.6 mm

Fresnel (30°) 27.9 mm 12.1 mm 24.1 mm 12.1 mm

Results of New FPix Geometries Study• The simulation assumes the operation of a new (undamaged) sensor at 100V bias and 263K

temperature in a 3.8T magnetic field. • The Fresnel option was studied at the design angle of 20° with respect to the beam axis and

also at 30° to assess how much the performance could be improved by increasing the angle and charge sharing.

• The results for tracks near the center of the acceptance are given in local and global coordinates. The local, sensor frame, coordinates are defined so that x is radial (or approximately radial) and y is azimuthal (or approximately azimuthal). They are also given in true projected r-phi coordinates to account for the effects of the rotation angles.

• The rotated vane works well. As in the current detector, the radial Lorentz-drift produced by the rotation angle can enhance the x-resolution (radial resolution) on both sides of the vanes and partly compensate the larger pixel size. The good azimuthal resolution is well matched to the good azimuthal resolution of the Si-strip tracker and the pixel barrel.

• The Fresnel options does not work as well. The nominal 20° tilts the sensors so that most tracks are nearly normal in the x-direction (radial direction), significantly reducing the charge sharing in that direction. Increasing the angle to 30° increases the Lorentz-drift induced azimuthal charge sharing and the geometrical radial charge sharing. Unfortunately, there is also a second-order Lorentz term (drift along the B-field direction) that tends to cancel the geometrical effect, worsening the resolution.

K. Arndt - Purdue FPix Upgrade Meeting - May 2009

31

FPIX Options for 2013 replacement/upgrade

Option

0

1

2

3

Cooling

C6F14

C6F14

CO2

CO2

Readout

analog 40MHz

analog 40MHz

analog 40MHz

m-tw-pairs

analog 40MHz

m-tw-pairs

Pixel ROC (total #)

PSI46 as now(4320 – 6480)

2x buffers(4320 – 6480)

2x buffers(9472)

2x buffers(11520)

Disks

Current 2-3

Current 2-3

3 new disks w/ Vanes

3 new identical disks w/ Vanes

Modules

672-1008

672-1008

592

720

Power

as now

as now

as now

as now?

January 2009

# of TBMreadout chains

288

288

592

720

K. Arndt - Purdue FPix Upgrade Meeting - May 2009

32

Phase 1 Pixel System Concept (April 2008)• Replace C6F14 with CO2 Cooling• 3 Barrel Layers + 3 Forward Disks (instead of 2)• Pixel integrated modules with long Copper Clad Aluminum pigtail cables • Move OH Boards and Port Cards out

10

0

20

20cm 40 60 80 100

FPIX service cylinder

BPIX supply tube

η = 1.18η = 1.54

η = 2.4

OH Boards+ Port Cards + Cooling Manifold moved out

Long CCA pigtails

K. Arndt - Purdue FPix Upgrade Meeting - May 2009

33

Z axis and Radius dimensions of Disk Concepts for Short 4-layer BPIX