Strip Module Design Short Strip Modules for Barrel region feature: - - PowerPoint PPT Presentation

Strip Module Design

• Short Strip Modules for

Barrel region feature:

• Silicon sensor plate
• Two hybrids
• 10 Atlas Binary Chip (ABC 130) with

256 readout channels.

• 1 Hybrid Control Chip (HCC)
• One Power board
• DC-DC conversion for parallel

powering of multiple modules 1

LBL Weekly Meeting (May 23rd 2017)

Metrology

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Confocal Microscopy

• Developing Metrology

using the confocal microscopy system.

• White light is refracted

and focused such that each color focuses at different heights.

• Measuring reflected lights

color gives the height.

3

Metrology Process

• Attempting to follow the

methodology from Brookhaven

• Scan 5 lines along the sensor

and 3 lines along the tops of the chips.

• Fit the bowing of the hybrid

and the bowing of the sensor.

• Extract chip heights

4

X Y

Problem with Glass Chips

• The measurements taken on the glass chips are not

accurate

• Heights under the glass is recorded.
• Refraction from glass shifts the measurement higher.

5

Top of glue dot Hybrid under glass chip Hybrid between chips

Electrical Module Construction

6

Electrical Module

• We had constructed 2

hybrids, each with 10 working readout chips, and 1 control chip.

• All testing and DAQ was
• successful. Ready to be

put onto a sensor.

• Hybrids are picked up by

the chips and glued to sensor overnight.

7

Module Construction

• One hybrid

connected easily.

• Second hybrid had a

chip come loose, under closer inspection 6 chips were loose.

• These were all

ultimately replaced.

8

Loose Chip

• Silver epoxy connected

with chip but not well with hybrid

• Initial height of glue dots

are specified to be 120 microns from tooling.

• Chips are then pushed
• nto hybrid to squish glue

down to 80 microns high.

• Appears that chip barely

made contact with hybrid.

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LBL Weekly Meeting (May 23rd 2017)

Metrology of Module

• Measurements taken along

hybrid and chips with SmartScope.

• Glue dot height is calculated

by:

• Fitting hybrid with 2nd order

polynomial

• Subtracting fit and chip width

from measured chip height.

• Two points on each chip

measured, allowing the slope to be calculated.

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Replaced Chip Loose Chips (hybrid 1) LBL Weekly Meeting (May 23rd 2017)

Chip Metrology

• Mapped out entire

back side of removed chip on confocal table.

• Able to map out

900,000 data points 10 microns apart in ~5 minutes

• Measurements with

50nm resolution in 10 micron steps in X-Y

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Module Construction (cont.)

• All readout channels are connected

to sensor with bonds (5120 readout channels.

• 4 rows of 64 bonds per chip

arching over each other to connect to sensor

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LBL Weekly Meeting (May 23rd 2017)

Bonding to frame and HV

• Connect biasing bonds

from hybrids to sensor.

• LV ground and HV

ground are shorted together through the HCC so that leakage current can be measured.

• In the future this will

be through the AMAC chip on the powerboard.

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Stealthy Bond Pad

Mapping out module

• Mapped entirety of module
• n confocal table.
• Should be able to clearly

see wire bonds and roughly see ASIC patterning and the strips themselves (very roughly).

• Scans measure 1.8 mm

lines within 500 micron focal window

• Requires merging of data

in Z and Y directions

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Tops of wire bonds Bond feet and top

• f ABC

Raw Data (darkness is height)

First Results

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• Image shows backside of chip and traces on hybrid.
• Merging can be greatly improved by taking into account

the brightness of each measurement

Next Steps

• Actually apply high voltage to the sensor and test our first

module!

• Quantify the noise on the module, then add a power

board to measure the differences in the noise.

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