1. 17/06/2010UK Valencia RAL Petals and Staves Meeting 1 DC-DC for Stave Bus Tapes Roy Wastie Oxford University

2. 17/06/2010UK Valencia RAL Petals and Staves Meeting 2 Stave Overview Carbon Fibre foam core plank Module Stave module controller Cooling pipes Size 1.2 m x 12cm 12 modules per side each with 2 hybrids

3. 17/06/2010UK Valencia RAL Petals and Staves Meeting 3 Stave Detail Bus tape Silicon Detector ABCN chip Hybrid flex PCB

4. 17/06/2010UK Valencia RAL Petals and Staves Meeting 4 Bus tape Tape stack up 100μm track & gap

5. 17/06/2010UK Valencia RAL Petals and Staves Meeting 5 Stavelet Module evaluation Two types Segmented shield Solid shield

6. 17/06/2010UK Valencia RAL Petals and Staves Meeting 6 Layout Details Serial Power Return HV Serial In Power protection control Wire bond pads TTC bus Data NTC

7. 17/06/2010UK Valencia RAL Petals and Staves Meeting 7 Openings for Bonding 150um 0.35mm & 0.65mm for HV pad Kapton Al Copper pad Adhesive Wire bond 4 masks required one for Al screen, one for Copper tracks and two cover layers

8. 17/06/2010UK Valencia RAL Petals and Staves Meeting 8 Bus Cable Geometry and Impedance 1 1 1 ~1 0.7 1 2 CF Cu ADHESIVE KAPTON Materials: Al foil 2mil, Dupont LF0100, Shinetsu CA333 2 mils, Cu 18 um, Kapton 1 mil, Adhesive Al

9. 17/06/2010UK Valencia RAL Petals and Staves Meeting 9 In house tape prototyping Thermal resistance –High conductivity glue layers Less material ie thinner Aluminium/kapton design –Aluminium 25μm on kapton 25μm for screen layer and 50 μm Al for track layer –Hatched screen to reduce material –Easier to handle Rapid prototyping possible

10. 17/06/2010UK Valencia RAL Petals and Staves Meeting 10 Stave09 and DCDC Powering – moving forward 2.Integration of DCDC onto a Stavelet (shortened 4 module stave), what we presently have: Stavelet Bus cable is (presently) designed for serial powering DCDC can be added, via the Power Protection Board drop-in connector, BUT is not ideal No DCDC power feed – it comes external to the Bus cable Drop-in connector is multi-functional – used for other serial powering topologies (SPi, …) Not electrically optimised for DCDC No ‘real estate’ available to integrate DCDC directly onto present Serial powered Stavelet The Power Protection Board is in the way! No access to Stave cooling contact. Propose designing a Stavelet Bus cable exclusively for DCDC Remove ALL serial powering trace routing from layout – freeing up space for DCDC requirements Power feeds to converters and control could maybe integrated onto cable Revisit Bus cable shielding, currently 2 flavours exist: Segmented – each module has it’s own individual shield (shields float w.r.t. each other) Continuous – no segmentation (maximal coverage) with modules AC-coupled to shield Optimise for DCDC… BUT The geometry of the Stave will remain the same at 500mm x 120mm – fixed by tooling. Availability of real estate for DCDC placement is still at a premium Slide from Powering meeting CERN 30/3/10 Ashley Greenall

11. 17/06/2010UK Valencia RAL Petals and Staves Meeting 11 Stavelet Geometry – ‘real estate’ for DCDC Available space per module for locating DCDC components (typically ~97.5mm x 6.2mm) Slide from Powering meeting CERN 30/3/10 Ashley Greenall

12. 17/06/2010UK Valencia RAL Petals and Staves Meeting 12 Stavelet – Bus cables Bus cable routing is on a single layer – no crossovers of traces allowed (no vias used!) Build is 18µm Cu with 50µm Kapton dielectric Expect majority of routing to stay as is e.g. Data I/O, HV distribution etc. But Serial Power Return and associated control can be removed. Data I/O (remains) Serial Power Return (not needed) HV (remains) Available for DCDC (6.2mm wide) Bus cable shielding, 2 flavours exist: Flexes are DC connected to their respective shield Flexes are AC connected to the shield SegmentedContinuous 120mm Insufficient Cu for DCDC power feed and return? 6mm trace width of 18µm Cu: <6A Need 2 traces for DCDC powering… Consider selectively adding more Cu (35µm) Move DCDC powering off Bus cable to PCB? If so, could we still use existing Bus cables? Slide from Powering meeting CERN 30/3/10 Ashley Greenall

13. 17/06/2010UK Valencia RAL Petals and Staves Meeting 13 DCDC Powering Implementation for stavelet Redesign CERN DCDC PCB to fit on to the stave bus tape connect with wire bonding. Limited to 6.2mm wide. Requires a narrow multilayer flex tape to bus the power in. DCDC PCB to tape and let it overhang, will need cooling ( add ceramic base board). 2mm side by side track single layer copper 105µm thickness 6.2mm CERN DCDC PCB

14. 17/06/2010UK Valencia RAL Petals and Staves Meeting 14 CERN DC-DC convertor DCDC PCB Hybrid outline Serial power track green sensor outline DCDC power track red

15. 17/06/2010UK Valencia RAL Petals and Staves Meeting 15 Full Stave DCDC With 130nm, will the power system be able to tolerate power dissipation and volt drop for 24 hybrid? Too long for one DCDC narrow PCB, would require two. (Flex/ridged) 105µm copper thickness Stavelet tape voltage drop & power