Ray Thompson Manchester Xmas Meeting 20/21 Dec 06

Ray Thompson , Julian Freeston , Andy Elvin

WP4 aims: look at Mechanical/Thermal/ Assembly issues

Utilise Atlas SCT experience effort weighted to latter end of period

• conducting Glues

• Assembly concepts

Calice WP4

30 layer Test beam Prototype

10k channelsConections to Silicon via Conducting Glue blobs

silicon - 1 cm2 pixels

Silicon tungsten layers

Marc Anduze, LAL

Conducting Glue - wildly exciting.

Ray Thompson Manchester Xmas Meeting 20/21

Dec 06

But you should see people panic when production faults start

Are small no of faults the thin end of a long wedge?

Silicon detectors expensive and irrecoverable

Atlas BarrelDetector mounting Brackets glued to Carbon Fibre cylinder

-CMS Tracker modules - Conducting Glue Bias connection to backplane Tony Affolder,UCSB

Change in Sensor Bias Resistance (144 sensors)From May to July 2005

0

10

20

30

40

50

60

70

80

90

-250

-150

-50

-30

-10

-8 -6 -4 -2 0 2 4 6 8 10

30

50

150

250

ohms

Frequency

Increasing glue resistance 1 month

Literature search Electronics industry experience Other Experiments - small no of tried glues

Conducting Glues Silver filled 2 part epoxy ( no mass loss no voids) Ag has high conductivity, Silver oxide conducts realise conductivity ~1/1000 solid Ag -interconecting particles choose particle size , viscosity,,cure temp EPO-tek 4110

Areas of interest - resistance aging

Interface problems oxide layer at Al/Ag interface Production wafers old

CTE mismatch Si /PCB - glue flexible Glass transition temp CTE change 50 x10-6 to 150 x10-6

Corrosion/electro chemistry – Ok for N2 atmosphere

Glue effects on wafer passivisation

Resistance measurementsKeithley 2000 DVM or 236 SMU

Labview

Glue test set up

Ray Thompson Manchester Xmas Meeting 20/21 Dec 06

Glue Robot

3x3 3mm square pixels

Standard 6X6 10mm square pixels

Prague wafers

Programmable Environmental chamber

Ray Thompson Manchester Xmas Meeting 20/21 Dec 06

Pc board / gold

Resistance snake Tests

R 0.1 ohm/50 dots

pcb

Silicon pads

Thermal Cycling

20—70 deg 1 deg/min

This years deliverable - Glue problem Study - Written up

Test set Up - Thermal Cycling Spring. Continuing with Prague samples

Start Assembly concept studies

•Start thinking about on pick and place techniques• for assembling detector planks

•Look at/ exploit existing stuff CMS/Atlas experience

•Generalised concept of a gantry with interchangable• tools pattern recognition software

Ray Thompson Manchester Xmas Meeting 20/21 Dec 06

Where now ?

InterchangeableVacuum pickup tool