1. PS Module Ron Lipton, Feb 28 2015 A bit of History During much of the conceptual design phase of the outer tracker we had focused on the “long barrel” design which featured a tight integration between tracker and trigger design All layers contained 10x10 cm 2 pixel/strip modules – We focused on design of these modules The barrel/disk design decoupled tracker from trigger. – 2S (strip-strip) modules in the outer layers – mostly covered by UK, Germany, CERN – PS Modules – designed by CERN – significant const. assumed in the US R. Lipton1

2. PS Module R. Lipton2 Al-CF Carbon fiber Strip hybrid DC-DC Opto hybrid sensor

3. Module Assembly – One Possibility Subcircuit production and testing – Design opto, DC-DC, Strip for test MPA (pixel sensor/ROIC) bumped assembly probe tests Fabrication of top/bottom sensor package – Alignment Assembly of subcircuits onto baseplate Subcircuit assembly onto baseplate – Test MPA placement and wirebonding – Final tests Burn-in Assembly onto rods R. Lipton3

4. Baseplate

5. Electronics modules

6. MPA module

7. Spacers

8. Top sensor and wirebonds

9. Baseplate

10. Mount assembled sensor stack – better alignment? Only If MPA chip bond pads can be supported by spacers

11. Top sensor and wirebonds

12. R. Lipton12

13. OT Fabrication Centers – Full tracker Parts 2 - AL-CF centers 2 Module CF parts centers 1 - Bias Circuit center 1-2 Front-End Hybrid QA center 1-2 Service-Hybrid QA center 1 Bare circuit process quality Ancillary electronics -By design groups FE ASICs - By design groups Sensors 5 Sensor Quality Control (2 PS) 2 Process Quality Control centers 2 Irradiation Test centers Integrated assemblies 1 - MaPSA production center - (QC, interface to companies) Module Assembly (3 PS, 4 2S) 2 PS Barrel Rod support assembly centers 1 Module storage and transport 1-2 TBPS Integration centers Tracker integration at CERN R. Lipton13

14. Full Module - Joe Conway notes from discussions last week Carbon base plate must be electrically isolated from lower sensor; – Could do this with a kapton sheet. Could this kapton sheet also be used to deliver the 800 volt bias to the sensor? – When in the assembly process would this sheet be installed? Co-cured with carbon fiber glued to sensor before the sensor assembly is glues to Carbon Fiber back plate – How would the circuit be electrically connected to the sensor wire bonding – geometry issues conducting epoxy – material (silver) problems How will the top and bottom sensors be aligned? – Use edges for alignment in jigs, but where would the pins be located? – Can we extend the bottom sensor longer than the top sensor so we can see optical fiducials on both sensors from above MAPSA sensors are bump bonded to the top side of the bottom sensor – The Aluminum-Carbon Fiber Spacer will be glued to these chips – Tops of these chips should be planar to better than 50 micron Why is the face of the spacer that these are glued to spec’d to 100 micron flatness? This could easily be better – The alignment of these chips is nominally set when they are placed by the machine and then when they are reflowed the surface tension of the solder somewhat aligns them Their alignment may be on the order of 5 micron Still may not want to use them for assembly alignment in jigs R. Lipton14

15. Will there be optical fiber tails off this piece? – From where – At what point in the assembly may this make things difficult Assembly sequence needs to be designed – Few assemblies put together and tested separately and then assembled onto back plate – Electronics assemblies put together and tested individually, then do we want to bond them to the back plate, test them as a group again before bonding the sensor assembly in the middle Could we get good epoxy spread under the sensor assembly in this order? Currently there is an “overhang” on the bottom of the sensor that prevents the electronics assemblies to be attached to the back plate before the sensor assembly The support method for the sensor edges during wire bonding needs to be better understood – Currently it looks like the edge of the sensor is supported by the “Hybrid Spacer” Al-CF piece. We think this will add difficulty to the assembly process, as well as have problems due to tolerance stack-up issues. – Are the carbon fiber sheets that will be bonded to the top and bottoms of the Al-CF spacers stiff enough to support the sensors during wire bonding? Or do we really need the Al-CF “ledge” machined into the spacer? Could the Al-CF spacers be replaced by carbon fiber/carbon foam sandwich panels? Certainly will have to worry about the carbon foam flaking R. Lipton15

16. Alternate Designs? R. Lipton16 Lower the optical hybrid to baseplate – better cooling, simpler layout..

17. Centers and equipment R. Lipton17 Test system CMM Auto. Probe station Assembly fixtures Auto Wirebonder Cooling system Burn-in system Gantry Hybrid TestingX Sensor pkg assembly X X MPA testingX X Hybrid assembly to baseX XX-X ? Sensor assembly to baseXX XXXXX Assembly to rodsXX X XX