15th January 2014 WP4 Meeting Oxford1 EoS PCB Mike Dawson University of Oxford

EoS PCB & Interlink 15th January 2014 WP4 Meeting Oxford2

EoS Flex-rigid assembly 15th January 2014 WP4 Meeting Oxford3 ‘C’ Spacer gives connector Pin clearance to stave interlink - no need for interlink cut out Flexible thickness 0.5mm 5mm bend radius Rigid thickness ~ 0.95mm (each side)

EoS Flex-rigid assembly 15th January 2014 WP4 Meeting Oxford4

EoS Flex-rigid assembly 15th January 2014 WP4 Meeting Oxford5

Summary Pin allocations have been decided for the Stave connector - Marcel. Position of the stave connector on the outer barrel layer is under review - space conflict with support structure. Shape/length of ‘flex pigtail’ under review – new design Interlink. We need to test the volt drop in the pigtail. A sample of the multilayer flex pigtail would also help us understand how ‘flexible’ it really is. 15th January 2014WP4 Meeting Oxford 6

EoS PCB & VTRx transceiver 15th January 2014 WP4 Meeting Oxford7

EoS PCB Light Peak transceiver 15th January 2014 WP4 Meeting Oxford8

Summary Jan Troska suggests we carry on working with the VTRx as the Light Peak alternative is 18+ months away. Non-functional samples of the Light Peak have been requested from AVAGO to evaluate the connectivity issues – not sure how robust the connector is. Is this design really suitable for our purposes? 15th January 2014WP4 Meeting Oxford 9

Cooling pipe temp sensors 15th January 2014WP4 Meeting Oxford 10

Cooling pipe temp sensors 15th January 2014WP4 Meeting Oxford 11 JT Thermistors ? (Semitec)

Cooling pipe temp sensors Common view is that these brackets were a nightmare to fit. Could we fit temp sensors to the electrical break or cooling pipe within the stave (during construction)? No external wiring. Wires could be replaced by a thin flex-pcb(s) built into the stave. Flex-pcb(s) would exit stave to connect to EoS pcb. 15th January 2014WP4 Meeting Oxford 12

Cooling pipe temp sensor flex-pcb 15th January 2014WP4 Meeting Oxford 13 Connectors mounted on EoS pcb, positioned away from wire bond area Inter-pcb flex width reduced to accommodate temp flexes

Possible method of mounting temp sensors 15 th January 2014WP4 Meeting Oxford14 Flats machined on end of Electrical Break (could be smaller – 0402 package available) Sensor wires exit on same side Sensors could be in vertical or Horizontal plane

Summary Current cooling sensor is (I believe) a Semitec JT Thermistor (0603 footprint). This component is insulated electrically and thermally by a polyimide cover. The FT version is an 0402 device mounted on a ceramic substrate. The flex-pcb would only need to 1mm wide to cover both pads. Need to be careful we don’t make the flexes fragile. Samples have been requested from Semitec for mounting tests. Discussing the options with Richard French. 15th January 2014 WP4 Meeting Oxford15

Grounding Ned wants the cooling pipe electrically connected to the common ground point on the EoS PCB(s). Ned has suggested that the Stave CF conductivity at HF may mean we don’t need a bracket (and wire) on the cooling pipe. A beryllium copper ‘leaf spring’ could be glued to the CF skin, which would be connected to an exposed area of the commono ground point on the EoS pcb. Need to discuss further with Ned, but he seemed happy with this idea in principle. 15th January 2014 WP4 Meeting Oxford16

Grounding 15th January 2014WP4 Meeting Oxford 17

Extras 15th January 2014WP4 Meeting Oxford 18

Extras 15th January 2014WP4 Meeting Oxford 19

Extras 15th January 2014WP4 Meeting Oxford 20

Extras 15th January 2014WP4 Meeting Oxford 21

Extras 15th January 2014WP4 Meeting Oxford 22