# Presentation: 882846

## BTeV Pixel DetectorPixel Module AssemblyandHalf-Plane Assembly

- Guilherme Cardoso
- James Fast
- C. M. Lei

## Pixel Module Assembly Tooling

- Take advantages of ATLAS pixel detector experience
- Port card (PC) to provide needed electrical circuitry and HDI holding by vacuum suction
- Extra long tabs of high-density interconnects (HDI) to provide testing and burn in
- Assembly steps summary:
- Align and glue a pixel module (consisting of the sensor bump-bonded with read-out chips) to an HDI;  Alignment tolerance : 100 microns
- Wire bond all electrical connections except that for high voltage (HV)
- For HV, solder a flex circuit to the HDI and bond the other end to the back of sensor with epoxy

- HDI

- Decoupling Capacitors and Termination Resistors

- Wire Bonds

- Wire Bonds

- FPIX Chip

- Sensor

- High Voltage

- Data PIFC

- Power PIFC

## Pixel Module Assembly Steps 1 & 2

- Assemble PC on a vacuum chuck
- Align and glue HDI on PC
- Wire bond HDI to PC
- Test HDI for opened traces

- Step 1

- Align pixel module (PM) to PM vacuum holder

- Step 2

- Port card (PC)

- PC vacuum chuck

- PM vacuum holder

- PM with alignment targets at corners exposed

## Pixel Module Assembly Step 3

- Position HDI with its vacuum chuck on to pixel module alignment jig
- Place spacers for PM vacuum plate
- (The thickness of the spacers will provide some clearance between pixel module and HDI)

- Step 3

- pixel module alignment jig

- spacers

## Pixel Module Assembly Step4

- Engage PM vacuum holder
- Align HDI to PM with the aid of CMM then vacuum hold the HDI vacuum chuck when done

- Step 4

- Stationary

- HDI with its chuck are moved freely under stationary PM

## Pixel Module Assembly Step 5

- Remove PM vacuum holder
- Change spacers (The thickness of the spacers will provide 50 micron glue between PM and HDI)
- Dispense epoxy on HDI
- Re-engage PM vacuum holder, and start gluing PM to HDI

- Step 5

## Pixel Module Assembly Step 6

- Glue flex circuit
- Complete HV connections
- Wire bond PM to  HDI

- Step 6

- Flex circuit for HV connections

- Note: The flex circuit is already soldered to the HDI at this point

## Pixel Module Assembly Step 7

- Transfer and fasten PC to HDI storage base plate
- Install HDI cover plate
- Conduct module burn in and testing

- Step 7

- HDI cover plate

## Pixel Module Assembly Step 8

- Remove HDI top cover plate and base plate
- Fasten PC on its vacuum chuck
- Remove HDI to HDI wire bonds
- Cut HDI at designated slots of PC
- Pixel module formed and ready for half-plane assembly

- Step 8

- cutting slots on PC

## Half-Plane Assembly

- Module placement accuracy of 5 microns is required
- Modules will be held by the HDI (wider section) so that fiducial targets at the sensor corners can be seen optically from the top
- 4-axis stages will be used for precise positioning of modules
- Optical targets visible on both sides of the substrate will be used to tie the alignment of modules on one side of the substrate to the modules on the other side
- Reliable gluing process is needed which will not damage the substrate or the sensors
- Even, thin joints require significant gluing loads
- Substrate must be supported from the back side with vacuum plates
- For second side, support is through first side sensors

## Half Plane Assembly Steps

- 0.  Glue flex cables on substrate

- 5.  Flip the half populated substrate and vacuum plate holding the silicon modules

- 6.  Repeat steps 1 and 4 with a new set of modules and vacuum plate.  Half-populated substrate starts at step 2.

- 7.  Wire bond HDIs to flex cables

- 4.  Align substrate to modules and allow glue to cure

- 3.  Apply glue on substrate

- 2.  Engage substrate into substrate holder then place on stage

- 1.  Align and load modules on vacuum plate

- 8.  Test all modules

## The Module Placement Setup

- Module is loaded individually with HDI side down onto module vacuum holder.

- 4-axis stages on rail

- Vacuum plate for substrate

- Vacuum plate for modules

## Align and Load Modules on Vacuum Plate

- Module is aligned using 4-axis adjustment of pick and place.  A common coordinate system is used to align a full set of modules.

- Leaf springs provide vertical compliance.

## Engage Substrate into Substrate Holder then on Stage

- Cart for module installation moved away and vacuum chuck rotated out of the way.

- Substrate on substrate vacuum holder

- All modules loaded – ready for substrate

## Align Substrate to Modules and Allow Glue to Cure

- 4-axis adjustment of substrate to modules

- Leaf springs provide vertical compliance.

## Flip the Half Populated Substrate and Vacuum Plate

- Place the substrate with first set of modules underneath on stage. – Repeat Step 2.

- Second side modules aligned on another modules vacuum plate. – Repeat Step 1 for another side of modules placement

## Finishing the Half-Plane Assembly

- Align substrate to modules and allow glue to cure. – Repeat Step 4 for another side of modules placement

## Status of Half-Plane Assembly

- Detailed fabrication drawings completed.
- Parts are being made.

## Summary

- The pixel module assembly steps have been thought through.   This design will be completed, prototyped and tested with prototype sensor and HDI when they are available.
- The design of the half-plane assembly steps have been completed.  Parts are being made and will be tested.