1/20/04 Slide 1Thermal Testing of TEC/TOB Hybrids at UCSB

Thermal Testing of TOB/TEC Hybrids at UCSB

1/20/04 Slide 2Thermal Testing of TEC/TOB Hybrids at UCSB

The CMS detector will run at –20 C in order to lessen radiation damage to the silicon

Why Thermal Test?

1/20/04 Slide 3Thermal Testing of TEC/TOB Hybrids at UCSB

Why Thermal Test Hybrids?

Some Hybrids fail at –20 C– APVs do not output– Hybrid fails to initialize– Noise increases in cold

(peltier current?)

APV: Analog Pipeline Voltage Mode Chip

1/20/04 Slide 4Thermal Testing of TEC/TOB Hybrids at UCSB

Set-up in Clean RoomSetSet--up in Clean Roomup in Clean Room

SetSet--up in Clean Roomup in Clean Room

ChillerChiller

Cold BoxCold Box

PC for MonitoringPC for Monitoring+ Controlling+ Controlling

ElectronicsElectronics

Gas/Water Flow ControlGas/Water Flow Control

1/20/04 Slide 5Thermal Testing of TEC/TOB Hybrids at UCSB

Cooling DownHow long should/does it take to get to –20?

Cold chamber

Peltier + PlateChiller

KTB 283

CT

AirKTS 295

Air Flow(0.05 L/min)

Water Flow (14 L/min)

1/20/04 Slide 6Thermal Testing of TEC/TOB Hybrids at UCSB

Simplifying things

)(8.4300 CBC TTK

WWP

hkxTTS

P SCI 1

)(

S= surface area of enclosure (m )k=thermal conductivity of walls (W/m C)h=convection factor (W/m C) x=thickness of walls (m)

2

2

CT BT

ST

1/20/04 Slide 7Thermal Testing of TEC/TOB Hybrids at UCSB

Calculating time to -20

CTmchk

xTTS SC

1)(

))(8.4300( CB TTK

WW

First order linear differential equation:

Solution: (T(t=0)=295K)

KKetT tC 9.2515.43)( )0045.0(

1/20/04 Slide 8Thermal Testing of TEC/TOB Hybrids at UCSB

Not quite…Calculation says that plate should reach –20 in ~14 minutes.

Actual time: ~21 minutes

Possible problems: • Unaccounted heat influx through leaks or grounding strips connecting plate to outside• Assumptions made are flawed• Missing term in differential equation

1/20/04 Slide 9Thermal Testing of TEC/TOB Hybrids at UCSB

Interfacing to a PC: ACDCInterfacing to a PC: ACDC

1/20/04 Slide 10Thermal Testing of TEC/TOB Hybrids at UCSB

Testing Software: ARCSTesting Software: ARCSAPV Readout Control SoftwareAPV Readout Control Software

CommunicatesCommunicatesWith ACDC With ACDC via TCP/UDPvia TCP/UDP

1/20/04 Slide 11Thermal Testing of TEC/TOB Hybrids at UCSB

What are we testing for?Shorted channels: On each clock, charge injected into every 8th channel. Shorted channels share, ADC amplitude is diminished.

128 Channels per APV-6 APV hybrids: 768-4 APV hybrids: 512

1/20/04 Slide 12Thermal Testing of TEC/TOB Hybrids at UCSB

What are we testing for?

Open Channels:Open Channels:Inject charge Inject charge throughthroughCapacitive coupling Capacitive coupling of pitch adapter to of pitch adapter to antenna carrying antenna carrying TTL PulseTTL Pulse

AntennaAntenna

Pitch AdapterPitch Adapter

1/20/04 Slide 13Thermal Testing of TEC/TOB Hybrids at UCSB

With Pulser Operational….

• Opens are also detectable in Pedestal & Noise Test

Plucked Bonds

1/20/04 Slide 14Thermal Testing of TEC/TOB Hybrids at UCSB

Thermal Cycle Test

“One Button” test

Three Sets of Tests:

• Pedestal & Noise

• Pulser

• Short Detection

1/20/04 Slide 15Thermal Testing of TEC/TOB Hybrids at UCSB

Automated Test ResultsFinal Report After Thermal Cycle Test:Lists -Shorts -Opens -Noisy Channels

1/20/04 Slide 16Thermal Testing of TEC/TOB Hybrids at UCSB

Testing & Replicating

UCSB Cold Box ready for full scale testing: ~28 hybrids per day

Fermilab Cold Box near completion

Mexico City Cold Box next on the list