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Download Last_news_largeMPGD - Indico
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Recent achievements and projects in Large MPGDs Rui de Oliveira 21/01/2009 RD51 WG1 workshop Content • Large GEMs – CERN production situation – Companies contacts • Large Bulks – CERN production situation – Resistive protection – Companies contacts Large size process • • • • • Conventional process : ok but difficult LDI : Problem of alignment Large glass mask : mask planarity problem Single mask + electro-etch: not accurate Single mask + chemical selective etching: ok Single mask technique quick reminder Raw material Single side copper patterning Chemical Polyimide etching differential etching or second metal etch Raw material Resist lamination UV exposure 100 meter 500mm 100 meter 500mm 2 meter x 500mm Drying 2 meter x 500mm Diff etch 2 meter x 500mm GEM 2 meter x 450mm Active area In theory with CERN equipments Polyimide etch 2 meter x 500mm Resist development 100 meter x500mm Copper etch 100 meter x500mm Goal • 2 meter x 450mm GEM • Single mask process • 2um Copper on both sides 70um 70um 55um 50 to 60um STD Single mask Single Mask GEMs produced in 2008 (650mm x 400mm) Problems: -large rims on the top -up to 90um copper diameter on top -uniformity on large pieces -lower gains Bottom Top Single Mask GEMs produced in 2009 (30mm x 30mm)!! Problems: -Still some delamination on top layer -Hole shape to deep for classical differential etching -Needs a protecting metal before second spray etch -uniformity seems good but need to be verified Bottom Top -Up to 30 different chemistry tested (for polyimide) -Effect of ultrasonic bath tested (for polyimide and metal) -NI/Au protection layer tested -removable Tin for production still to test Detail on second metal spray etch Chemical Polyimide etching NI/Au or Tin plating on top Resist protection on bot Conventional spray etching stripping : Tin on top Resist on bot • Next large GEMs productions – Kloe 700mm x 450mm – DHCAL 1000mm x 330mm • 2 slides following given by Mr Jae Yu UTA’s 100cmx100cm Digital Hadron Calorimeter Plane Readout Board 330x500 mm2 Base steel plate, t=2 mm Future large volume production Visit November 2008, organized by Changwon university Company: NEW flex technology Started in 1992 Activities: circuits for Telecom, displays and Automotive 400 Employee Situation: South Corea near Seoul Double sided flexes capacity 10 000 m2/month ! Smaller than needed for GEMs Roll to roll exposure, etching and stripping Strategy for low to medium volume • Use the CERN equipment • Create tool to handle 2meter GEMs for chemical treatment (done) • Subcontract artwork ( 0.5m x 2m) (Ok) • Upgrade UV exposure and Polyimide etching equipment ( but still dead baths) – Existing ones sufficient to start Strategy for large volume • Subcontract roll to roll copper patterning • Buy or create equipment for roll to roll polyimide etching (spray or static etching) • Buy equipment for roll to roll Tin plating • Buy equipment for roll to roll Tin stripping • Subcontract roll to roll electrode definition • Buy equipment for roll to roll cleaning Micromegas Bulk • About to start 1 large Bulk for SLHC – Should be built within 1 month • Points to be verified (production) – size capability – Resistive protection against discharges – Mesh sectors creation 1300mm x 350mm Active area 1500mm x 500mm Outer size Mesh Drift frame Gas box 6 different patterns 500um Full plane High voltage supply 6 sectors + drift 250um 500 um pitch 400um line and space Signal outputs 250 um pitch 150um line and 100um space 250 um pitch With resistive protection Resistive protection Spark or charges 50 to100um Signal out PCB Copper Photo-imageable coverlay Resistive dot, pad or line Spark or charges dot dot Signal out R Serial resistor limiting max current High enough to limit energy of spark C Serial parasitic capacitor High pass filter High enough to transfert signal charges Spark or charges dot dot Signal out R Serial resistor limiting max current High enough to limit energy of spark C Serial parasitic capacitor High pass filter High enough to transfert signal charges Change the paste 100 Ohms to 1 MOhms Spark or charges dot dot Signal out R Serial resistor limiting max current High enough to limit energy of spark C Serial parasitic capacitor High pass filter High enough to transfert signal charges Change the paste 100Ohms to MOhms Introduce a metallic hat C Increase the distance C Dot architecture -Min : 0.15mm diameter -Pitch: 0.25mm -Possibility to avoid alignment between track and dots Pad architecture -needs alignment Detail on the sector partitioning Coverlay 0.8mm 0.6mm 0.8mm Read-out board Mesh Milling or scalpel cut Scalpel cut prefered No dust! Spacer pillar First contact for large size large volume productions CIRE Group 8 companies in France Possibility to make large patterns in some of them They have already produced some small BULKS Other details are being discussed We are ready to discuss also with any other company Thank you
