CERN PH/DT 30/01/14 Francisco Perez Gomez CERN PH/DT

Status report on MicroMegas

mechanics

CERN PH/DT

30/01/14Francisco Perez Gomez CERN PH/DT

Concept remind Vacuum table manufacturing and

measurements MM panels design Construction of the first panel

◦ Measurements and results Status and future plans

30/01/14Francisco Perez Gomez CERN PH/DT

Content

A sandwich of two soft skin is glued without mechanical constraints.

A sandwich is:o One glass fibre skin (0.5mm)o Aluminium honeycomb surrounded with an aluminium frameo Second glass fibre skin (0.5mm)

Sandwich schematic view

Francisco Perez Gomez CERN PH/DT

Concept (1/2)

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Manufacturing concepto The skins are sucked with two vacuum tableso The vacuum table surfaces are perfectly flato The vacuum table surfaces are set in parallel position


Concept (2/2)

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Dimensions: 1300X600 Manufactured at CERN Use granite table (flatness

<10 mm) as mould Outer surface: Epoxy gel coat

‘’EP Gel coat Weiβ’’ (1+1 reinforced layer).

Structural layer: Glass fibre “Glasgewebe 92150 FK-144 345g/m2 Leinwand’’ + AXSON Epolam 5015 (5 layers).

4 perforated sides aluminium honeycomb.

Araldite 2011

Vacuum table components

30/01/14Francisco Perez Gomez CERN

PH/DT


Vacuum table exploded view

Gel coat + Glass fibre (3.5mm)

Glass fibre (3mm)

Perforated Al Honeycomb (60mm)

Al profile (60X30mm)Al inserts

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MM Vacuum table (1300mmX600mmX60mm)

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Vacuum Table Cross section

Perforated Al honeycomb

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Vacuum table inserts

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Vacuum table QC

CERN Metrology lab CERN PH/DT

Temperature: 20°C Planarity : 0.077mm

Temperature : 21°C Planarity : 0.08mm

Temperature : 22.5°C Planarity : 0.03mm

There’s a temperature influence on flatness to be taken into account (work at constant temperature ± 0.2°C).

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Reference holes on boards for alignment Ultem plugs to avoid drilling panels after

assembly All plugs are precisely pre-glued on the

board using a dedicated tool Aluminium frame pre-assembled on tool Aluminium honeycomb Araldite 2011 is the best candidate for

gluing Panel manufacturing in one shot

MM panel Design

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4 reference holes.

Assembly tool

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4 reference holes.

Board alignment on assembly tool

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Ref.

Ref.

Board Alignment

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2 pins Ø5g6 X Ø6,5g6


Ø5.50

Ø5.0

Reference plugs gluing

Ø5.50

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Reference plugs gluing

Alignment pin

Reference plug glued

Cyanoacrylate 3M

EC50

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Ref.

Spacer

Board

Alignement

All plugs glued

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Ref.

Board installation and indexation on vacuum table

… vacuum pump ON

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Aluminium frame assembly

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2 reference holes per profile

Aluminium frame assembly

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Aluminium frame installation

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Honeycomb installation

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Ref.

Ref.

2nd board installation on 2nd VT

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Vacuum Table Ref.

Vacuum Tables alignment

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Vacuum tables alignment

Precision shims (11,6mm)

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Polymerisation

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Real Assembly of the first panel

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Real assembly of the first panel

Francisco Perez Gomez CERN PH/DT 30/01/14




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Results….

Upper side view Some measurements

Top side flatness: 160µm (max-min)

Bottom side flatness: 90µm (max-min)


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Results I Planarity: 40 µm (rms)


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Results II Planarity: 22 µm (rms)

Idea: Produce a spacer made from several pieces.

Straight pieces have the same profile with different lengths for mass production

Two symetric models of corner piecesTwo ref holes/ element for alignment

Use granite table in order to obtain a flat, parallel and precise surface for the gluing of the mesh

Liquid glue (Axson Epolam 5015) for the mesh gluing

Use “capillary effect”


Spacer and mesh gluing

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Assembled and glued on drift panel using alignment holes

Mesh glued on well defined surface.

May act as gas manifold.

Large gluing area. Ground connection

Mesh support frame (Spacer)

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Spacer gluing on drift panel procedure

The gluing procedure is first tested in a smaller prototype (200X200mm) In particular the assembly of the corner pieces and leak tightness were verified.

Create a new plane, parallel to drift panel

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Drift

Gluing zonesDrift

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Laying on precise shims on granite table

Teflon pins


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Mesh gluing on dedicated tool

Plexiglass mould

Mesh frame

Mesh support installed under “press”


Injection of glue

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Injection points distance 100mm


Mesh after polymerisation

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Planarity 40µm

Prepare all needed elements for 1 panel assembly (frame, plugs, pins, etc..)

Manufacturing of 1 full set of mesh support. Investigation of temperature and humidity influence on

VT flatness Drill reference holes on vacuum tables. Assembly and QC of 1 panel for tooling and procedure

validation Test on gas distribution Test on mesh gluing Ground connections tests Test on zebra fixation Electrical tests on Zebra connectors


STATUS“Future plans and tasks 15.01.14”

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Understand deformations on the first panel Improve and tune the panel manufacturing

procedure Build the first real panel ….


Future Plans

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spares

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Zebra connector for FE connection

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Board connection

Alignment pin

Board

Fixation pins and ground connection

Deflection = 0.01mm

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View of Zebra connector encapsulated

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Documents

CERN PH/DT 30/01/14 Francisco Perez Gomez CERN PH/DT