1. Atsuhiko Ochi (Kobe University) Yousuke Kataoka (ICEPP) ATLAS MicroMEGAS meeting, 19/01/13

2.  We need resistive strips  Screen printing is one of hopeful method.  However, there are some difficulty remained... ◦ Fine pitch of the strips  400  m spacing is ok (like zebra chamber and Japanese chamber), but more fine pitch is required ? ◦ Uniformity for large size (1m X 1m)  Technician in company said that it will be difficult to make large size. 2013/1/29 A.Ochi Kobe Univ.2

3.  We have Two approaches now!  (Using budget from Kobe and ICEPP) ◦ Drawing the strips using dispenser by resistive polyimide ◦ Forming the strips by spattered thin metal 2013/1/29 A.Ochi Kobe Univ.3

4.  We have a small dispenser system in KEK, and we will try to use this for next prototype. ◦ There are some parameters to be modified …  Drawing pressure  Drawing speed  Diameter of the nozzle  Distance from board to nozzle ◦ Those parameters should be modified by viscosity of the material 2013/1/29 A.Ochi Kobe Univ.4

5.  Conditions: ◦ Sample material: Carbon doped polyimide (Toray) ◦ Substrate: Kapton sheet ◦ Temperature: 25 ◦ Diameter of dispenser: 100  m ◦ Line pitch: 400  m  Good samples 2013/1/29 A.Ochi Kobe Univ.5 Pressure: 100kPa, Line drawing: 10mm/sec Pressure: 50kPa, Line drawing: 15mm/sec ~ 250  m ~ 120  m

6.  However, the solution of condition with good line drawing is very narrow ◦ Very fine tuning of the gap between nozzle and board is required  Finesse of a few tenth micro meter is required  We need more study for fine drawing (in these couple of month) 2013/1/29 A.Ochi Kobe Univ.6 Bad sample: With a little bit large gap Bad sample: Too far or too fast drawing

7.  Spattering metal on a substrate provides high resistivity (~1M  /sq.)  Industrially, spattering process is available using large chamber. ◦ 1800 mm x H2000 mm ◦ Maximum board size: 1m x 4.5m (flexible board)  We will make large resistive strips, then we will test it as a candidate of production process. 2013/1/29 A.Ochi Kobe Univ.7

8.  Very fine structure (a few tens micro meter) can be formed using photo resist. (same as PCB)  We will make a first test in this February 2013/1/29 A.Ochi Kobe Univ.8

9. Screen printingDrawing by Dispenser Spattering SizeOK (>1m x 2m)Probably ok (need special machine) OK (>1m x 2m) Fineness (Strip pitch) ~ 400 um~ 200 um ? < 100 um Production hour/m^2 ~ 1h~ 100h/nozzlesA few h Cost/chamberVery low (If special printing machine is need, we have to include it.) Very low (but initial machine for large size will be several hundreds kCHF) ~ 1kCHF (no special facility needed) ResearchSmall prototypes are tested Just start to make strips Just ordered to industrial company. (to make a sample) 2013/1/29 A.Ochi Kobe Univ.9 This table is only my rough estimation

10. DatePlans Feb. 2013Sample strip board (without micro mesh) will be made and tested. We will decide which technology will be apply for next small MM prototype. Mar. 2013Producing MM prototype with new technology Apr.~Try to make a large size sample 2013/1/29 A.Ochi Kobe Univ.10