1. detector development readout electronics interconnects bump bonding
flex cables
KPiX readout chip
mechanical prototype
R Frey SiD Cal 18Feb2010

2. overview
Revised
Overall Goal: Produce test module using same technology as collider detector
The necessary silicon sensors in hand (Hamamatsu v-2) – Oregon
Readout chip: KPiX-8 (256 ch) → KPiX-9 (512) – SLAC
1024 ch required
Interconnects – Davis
KPiX-sensor: gold-gold bump-bonding trials in progress
Flex cable: need test of ASC cable-sensor connections
Target: Assemble module and test in beam (SLAC?)
R Frey SiD Cal 18Feb2010

3. Silicon-Tungsten ECal
Progress in integrated analog-digital electronics, interconnect technologies, and silicon sensors have made possible the advent of very dense, imaging electromagnetic calorimeters for future detectors.
Highly segmented transverse readout (silicon).
13 mm2 pixels
Particle separation for PFA (jets), tau decay id, etc
Dense (tungsten) with very small readout gaps (1 mm)
Small Moliere radius – resolve individual showers: photon imaging and particle separation (PFA), photon vertexing
Longitudinal readout (~30 layers)
imaging of showers and MIPs
good energy resolution (17%/√E ).
R Frey SiD Cal 18Feb2010

4. Interconnect issues: Technologies being considered
Prototyping
Production
KPiX to Sensor
Gold Stud Bonding
(Epoxy/Thermo-compression)
Indium/Solder Bump Bonding
Flex Cable to Sensor
Solder Balls
Conducting Epoxy
Anisotropic Conducting Film
(ACF)
ACF?
Indium/Epoxy
ACF/Epoxy/Solder

5. KPiX with Gold Studs
Studs are well-formed and centered on the 70x70 mm pads.

6. Gold Stud Attachment Three possibilities:
Conducting Silver Epoxy. High degree of bump height uniformity required. No limit on number of bumps. Low temp and pressure. Good success for large pads (>100 um). Work in progress for 50 um pads.
Thermo-compression. Typically, high temp and pressure: C and g/bump. Machine limit ~ kg => Limits total number of bumps.
Thermosonic. Lower temp and pressure: 150C and 75g/bump. Limit on total number of bumps because of the limit on total deliverable ultrasonic power without breaking the chip.
bullets 6 6

7. Thermoplastic Conducting Adhesive (ACF)
Btechcorp:
Metal fibers in a matrix ~2 x 107 fibers/in2
Low Cure pressure: 50 psi
Resistive
Conductive
8 um nickel fiber structure.
close-packed array
 Initial results are promising. Goal for Flex Cable pads (100 sq mil) is ~100 mΩ, which is achievable.

8. KPiX and Si sensors Continued evaluation/debugging of KPiX
Noise measurements
Found lockup mode in KPiX-7,-8
Should be fixed in KPiX-9
With a 512-channel KPiX-9 bump-bonded to a sensor, can get noise measurements for the full range of input capacitances and resistances.
Goal for ~ spring
1300 e rms
R Frey SiD Cal 18Feb2010

9. Summary goals, progress, plans
Year 1
Year 2
Year 3
Goal from proposal
Complete R&D on component technologies
Assemble test module, start beam test
Beam test, data analysis
Status
Sensors – OK
Tungsten – OK
KPiX – need 1024 channel chip
KPiX-Si bumps: need to converge on technology
Flex cable – ok
Cable-Si connect: needs R&D
Need the integrated tests first.
Flex cable can be made independently; same for DAQ
tbd
Plan
Hope to have 1024 KPiX and bumping technology by summer for combined testing in lab.
Need to finalize cable-Si tech
Re-evaluate resource needs – so far ok.
If integrated tests look OK, begin planning for beam test. Assume SLAC for now.
R Frey SiD Cal 18Feb2010