assembling the complete stave on the carbon fiber sector support

4-06-02 ITS week CERN R. Dima ALICE SPD, INFN-PD

Assembling the complete stave

on the

Carbon Fiber Sector Support

4-06-02 ITS week CERN R. Dima ALICE SPD, INFN-PD

Wire bonding on interior side

4-06-02 ITS week CERN R. Dima ALICE SPD, INFN-PD

Mounted stave cross section

4-06-02 ITS week CERN R. Dima ALICE SPD, INFN-PD

1. Set the Carbon Fiber Sector Support in initial position

2. Align the halfstaves

3. Apply the glue (adhesive dependent)

4. Mount the complete stave

5. Curing & force control (adhesive dependent)

Operation sequence

4-06-02 ITS week CERN R. Dima ALICE SPD, INFN-PD

1st step: Set the carbon fiber support sector in position1.1 Mount the CFSS in indexing device

1.2 Adjust the position with the first duct horizontal

1.3 Lock in this position (it will be considered the reference position)

Horizontal surface

4-06-02 ITS week CERN R. Dima ALICE SPD, INFN-PD

4-06-02 ITS week CERN R. Dima ALICE SPD, INFN-PD

2nd step: Align the halfstaves

(each halfstave will be held by its own “B” support)

2.1  Put the halfstaves in the “P” support

2.2  Align the halfstaves relative each other

2.3 Align the complete stave with the reference surface

A few sets of holding, aligning and supporting “B” and “P” devices have to be developed together with Bari colleagues.

4-06-02 ITS week CERN R. Dima ALICE SPD, INFN-PD

“B” support

(holds 2 ladders)

“P” support

(holds the complete stave)

4-06-02 ITS week CERN R. Dima ALICE SPD, INFN-PD

AIT cool-gel 7018

•Curing time: 24 hours

•Pressure: 10-15g/cm2= 83-125g/stave

•Removable

Choice of the adhesive-

an important impact in tooling designGeneral requests:

•High thermal conductivity

•Electrical insulator

•Removable !

Valid choices:

•AIT cool-gel 7018 (used by ATLAS experiment with good results)

•thermoplastic adhesive films

•…

4-06-02 ITS week CERN R. Dima ALICE SPD, INFN-PD

3rd step: Apply the glue (AIT cool-gel 7018 case)

The mask

4-06-02 ITS week CERN R. Dima ALICE SPD, INFN-PD

3.1 Position the mask on the carbon fiber support (relative to the reference surface)

3.2 Apply the glue over the duct (strips) and carbon fiber (spots on each side of the duct)

3.3 Spread the glue

3.4 Remove the mask

4-06-02 ITS week CERN R. Dima ALICE SPD, INFN-PD

Position the mask Apply the glue

Spread the glue in order to obtain an uniform layer ~100-120 m

Remove the mask

4-06-02 ITS week CERN R. Dima ALICE SPD, INFN-PD

4-06-02 ITS week CERN R. Dima ALICE SPD, INFN-PD

Glue dimensions variation vs. pressure applied

0,00

0,50

1,00

1,50

2,00

2,50

10 15 20 25

Pressure [g/cm2]

DX

, DY

[m

m]

DX

DY

X

Y

AIT cool-gel 7018

test results

Glue thickness vs. pressure applied

70,0

80,0

90,0

100,0

110,0

120,0

10 15 20 25Pressure [g/cm2]

Th

ick

ne

ss

[

m]

After pressing footprint

Mask footprint

4-06-02 ITS week CERN R. Dima ALICE SPD, INFN-PD

p=10g/cm2

(=1,=2)

p=15g/cm2

p=20g/cm2 p=25g/cm2

4-06-02 ITS week CERN R. Dima ALICE SPD, INFN-PD

4th step: Mount the complete stave

4.1 Approach the complete stave to the carbon fiber

4.2 Mount the stave over the carbon fiber and duct in final position

4-06-02 ITS week CERN R. Dima ALICE SPD, INFN-PD

5th step: Curing & force control

5.1 Apply the pressure and cure the glue (24 hours AIT cool-gel 7018 glue)

4-06-02 ITS week CERN R. Dima ALICE SPD, INFN-PD

Removability issue:

•Possible only by chemical way (acetone)

•The solvent should be injected and penetrate all length of the stave

•Needs quite some shear & pull

•Difficult to separate the components also due to the superficial tension of the liquid

•Can be removed just one stave without disturbing the others ?

4-06-02 ITS week CERN R. Dima ALICE SPD, INFN-PD

1. Fast and safe removability (by heating)

2. Fast mounting-curing (seconds vs. hours)

3. Almost no pressure needed

4. Can be delivered in the requested shape (no mask needed)

Arguments for the thermoplastic films:

4-06-02 ITS week CERN R. Dima ALICE SPD, INFN-PD

What next:

•Test the thermoplastic adhesive film considering the corellation with the tooling design

•Design the tooling for the steps independent of the adhesive type