Production of THGEM at ELTOS S.p.A.

1. Production of THGEM at ELTOS S.p.A. Fulvio Tessarotto Company profile Production procedures Small size THGEM prototypes Large area THGEM photon detector The production of the first set of 600 x 600 mm2 THGEM prototypes Fulvio TESSAROTTO

2. Company profile (seen from a client) For the production of THGEMs by industry Rui de Oliveira suggested us to contact an Italian pcb producer: the company ELTOS S.p.A. Founded in 1980 by Dr. Riccardo Pinamonti, in Arezzo (Tuscany), a place with centuries long tradition in gold handcraft almost 100 workers; turnover > 12 M€ / year; page: www.eltos.it producing of all kinds of pcb’s, mainly for foreign customers many labs and research institutes among clients (CERN LHCb award) typically working on special products and small orders treating more than 30 different codes / day using many high-tech machines and newly developed techniques Fulvio TESSAROTTO

3. Production of small size THGEM prototypes At the beginning of 2008 we ordered to the ELTOS Company 13 groups of THGEM prototypes with 30 x 30 mm2 of active area. common prototype parameters: thickness: 0.4 mm, Cu thickness: 35 μm, holes diameter: 0.4 mm, pitch: 0.8 mm; material: R-1566 Panasonic (halogen free, anti CAF) POSALUX ULTRASPEED 6000LZ 6-spindle-roboter 10 samples per type 180,000 turns/min, Ø down to 0.15 mm Nominal CNC drilling tolerance: +- 10 μm Fulvio TESSAROTTO

4. 13 series (different rim or production) Fulvio TESSAROTTO

5. Documentation and packaging Fulvio TESSAROTTO

6. Original “Weizmann” THGEM production process Raw material Resist covering Image transfer and etching Stripping Drilling Fulvio TESSAROTTO

7. ELTOS “small rim” production process similar to CERN one, presented by Rui de Oliveira (CERN RD51 Worshop, Sep. 10-11, 2007) Raw material Galvanic Sn Drilling “10 μm” rim Sn stripping Fulvio TESSAROTTO

8. example of “small rim” (25μm) production Fulvio TESSAROTTO

9. ELTOS “large rim” production process Raw material Drilling Photo-resist Image transfer “100 μm” etching Fulvio TESSAROTTO

10. example of “large rim” etching production Fulvio TESSAROTTO

11. ELTOS “global etching” production process Raw material Drilling Global etching (no protection) proposed by Dr. Riccrdo Pinamonti and used for some of the prototypes Fulvio TESSAROTTO

12. example of 10 μm “global etching” production Fulvio TESSAROTTO

13. pure drilling production process Fulvio TESSAROTTO

14. double drilling production process Fulvio TESSAROTTO

15. Vmax (= discharge limit in pure N2) For the characterization of the small prototypes, listen to Elena Rocco and Jaroslav Polak talks tomorrow different production techniques  different behaviors Fulvio TESSAROTTO

16. The second series of small size pieces Fulvio TESSAROTTO

17. th. 0.8, diam. 0.4, no rim Fulvio TESSAROTTO

18. th. 0.6, diam. 0.3, “5 μm global etching rim” The Cu layer thickness is reduced from 35 μm to 30 μm Fulvio TESSAROTTO

19. Toward larger areas: Prototipes: Small, active area 30 x 30 mm2 Medium, active area 100 x 100 mm2 Large, active area 576 x 576 mm2 Next step: many engineering problems to be faced  build a first tentative prototype box for addressing one by one the problems; start with a large THGEM with “standard” parameters 0.6, 0.4, 0.8 Fulvio TESSAROTTO

20. 100 x 100 mm2 THGEM (CERN production) thickness: 0.2 mm diameter: 0.2 mm pitch: 0.5 mm rim: ~ 10 μm Fulvio TESSAROTTO

21. Fulvio TESSAROTTO

22. Fulvio TESSAROTTO

23. 0.5 mm 0.2 mm Fulvio TESSAROTTO

24. Fulvio TESSAROTTO

25. Fulvio TESSAROTTO

26. Fulvio TESSAROTTO

27. Structure of the large areaprototype detector Anode pads Al frame Al frame THGEMs Stesalite frames 600 mm 600 mm Fulvio TESSAROTTO

28. The aluminium frames and the stesalite frames have been produced to allow assembling one prototype detector. The anode consists in a multi-layer pcb of 3.6 mm thickness, 600 x 600 mm2, segmented in 2304 pads of 1.2 x 1.2 cm2 in the internal side, and 288 connectors for direct mounting of electronic boards on the external side. Two such pcb’s have been produced for us by ELTOS S.p.A. The uniformity of the pad surface is guaranteed by using a recently developed technology: “Cu viafill” used for filling blind microvias Fulvio TESSAROTTO

29. Cu viafill technology Fulvio TESSAROTTO

30. anode pcb Fulvio TESSAROTTO

31. anode pcb pads Fulvio TESSAROTTO

32. Production of 600 x 600 mm2 THGEMS We ordered 3 large THGEMs with 576 x 576 mm2 active area. The geometrical parameters are: thickness = 0.6 mm, hole diameter = 0.4 mm, pitch = 0.8 mm, rim = 5 μm. They have been produced by ELTOS S.p.A. using single spindle machine, and single piece drilling (for small size prototypes stacking of two pcb’s during drilling was used). There are about 600,000 holes per piece. The drilling took about 30 h / piece, but pieces were produced in parallel.Tools are replaced after 2000 holes. The reference price for drilling is 1€ for 1000 holes. The other production operations (~5μm rim, Ni-Au, …) add a similar amount to the final price. Fulvio TESSAROTTO

33. Pluritec Multistation Evolution at ELTOS Working area: 630 x 765 mm2 180,000 turns/min 20,000 holes/hour Storage: 840 tools Controlled diam., depth and run-out Fulvio TESSAROTTO

34. 600 x 600 mm2 THGEM protoypes ~600,000 holes/piece (very large gerber file) Ø: 0.4, p.: 0.8, th.: 0.6 mm rim: 5 μm (micro-etching) Ni-Au coating Fulvio TESSAROTTO

35. THGEM Fulvio TESSAROTTO

36. 600 x 600 mm2 THGEMs Fulvio TESSAROTTO

37. Conclusions The ELTOS S.p.A. Company in Italy has recently gained significant experience in the production of THGEM prototypes of many different types. In order to optimize the procedures for THGEM production it is very important to know the production details and to correlate them to the performances of the prototypes. This work has started with a large set of 30 x 30 mm2 THGEMS which have been delivered and tested. The first set of 600 x 600 mm2 THGEMs has been produced and delivered last week. Industrial production of THGEMs may be close to become real. Fulvio TESSAROTTO