Status of HFCBs:
1. 3_P2
1.1. Assembled at Screaming Circuits.
1.2. Assembled on module PP1.
1.2.1. Status: Module debugging.
1.3. HFCB Notes:
1.3.1. Regulators for digital replaced with an inductor for the Top and a jumper for the bottom.
1.4. Wire bonding Notes:
1.4.1. Bent bonds on U2.
1.4.2. U2 and U3 have same CID.
1.4.3. Missing bond on pad 10.
1.5. Module notes:
1.5.1. High resistance on bottom I to F sensor (.3-400M ohms).
2. 3_P6
2.1. Assembled at Screaming Circuits.
2.2. Not assembled on module.
2.2.1. Status: HFCB debugging.
2.3. HFCB Notes:
2.3.1. Regulators functioning.
2.3.2. Shift control positive pad lifted on Nanonics 51 pin connector.
2.4. Wire bonding Notes:
2.4.1. Analog GND bond missing on right side. Repaired at Jlab.
2.4.2. U2 and U3 have same CID.
2.4.3. Missing bond on pad 10.
3. 2_P6
3.1. Assembled at Screaming Circuits.
3.2. Assembled on module PP2.
3.2.1. Status: Module debugging.
3.3. HFCB Notes:
3.3.1. Regulators functioning.
3.4. Wire bonding Notes:
3.4.1. U2 and U3 have same CID.
3.4.2. Missing bond on pad 10.
3.5. Module notes:
3.5.1. High resistance on Top I to F sensor (11M ohms).
4. 2_P3
4.1. Assembled at Compunetix.
4.2. Assembled on module PP3.
4.2.1. Status: Module debugging.
4.3. HFCB Notes:
4.3.1. Regulators functioning.
4.3.2.Measured 69K ohm short during resistance tests, fixed during burn in.
4.4. Wire bonding Notes:
4.5. Module notes:
4.5.1. High resistance on bottom I to F sensor (343ohms HV+ to F).
4.5.2. High resistance on top HV+ to H (854K ohms).
5. 2_P2
5.1. Assembled at Compunetix.
5.2. Assembled on module PP4.
5.2.1. Status: Module debugging.
5.3. HFCB Notes:
5.3.1. Regulators functioning.
5.3.2. Visual scratch on LVDS trace, but measurement shows (<.1 ohm) good continuity.
5.3.3. Short between HV+ Top and GND detected during burn-in and verified during resistance
tests. Attempt to burn out short unsuccessful, but revealed short location in bottom layer
GND pour. Section was removed by cutting, short is gone. Manufacturer and testing
vendor notified, procedure revised. All issues with boards will be communicated to JLab
from MicroCraft. All repairs will be retested. A traveler document will be incorporated with
QC/QA.
5.4. Wire bonding Notes:
5.5. Module notes:
5.5.1. Kludge using gold plated kapton for HV + to sensor.
5.5.2. Has high current on top side. Trips HV supply.
6. 1_P5
6.1. Assembled at Compunetix.
6.2. Assembled on module PP5.
6.2.1. Status: Module functioning.
6.3. HFCB Notes:
6.3.1. Regulators functioning.
6.3.2. Delamination of bottom side HV- bond pad detected post population. Resistance
measurements indicate plane connection.
6.4. Wire bonding Notes:
6.5. Module notes:
6.5.1. Kludge using kapton tape over Bus Cable and gold plated kapton over tape for HV+
connection to sensors.
7. 2_P4
7.1. Assembled at Altron.
7.2. Not assembled on module.
7.2.1. Status: HFCB population reception.
7.3. HFCB Notes:
7.3.1. Regulators functioning.
7.3.2. Solder in bond pad areas for all chips.
7.4. Wire bonding Notes:
7.5. Module notes:
8. 2_P5
8.1. Assembled at Altron.
8.2. Not assembled on module.
8.2.1. Status: HFCB population reception.
8.3. HFCB Notes:
8.3.1. Regulators functioning.
8.3.2. Solder in bond pad areas for all chips.
8.4. Wire bonding Notes:
8.5. Module notes:
9. 1_P4
9.1. Assembled at Altron.
9.2. Not assembled on module.
9.2.1. Status: HFCB population reception.
9.3. HFCB Notes:
9.3.1. Regulators functioning.
9.3.2. Solder in bond pad areas for all chips.
9.4. Wire bonding Notes:
9.5. Module notes:
======================================
3P2 – PP1
2P6 – PP2
2P3 – PP3
2P2 – PP4
1P5 – PP5
3P6 – Trace damaged on Nanonics connector, Marc repaired. U1 & U2 replaced prior to repair.
Still being debugged.
Back plane resistance check on mechanical module
2/13
Top side:
H sensor to I = 9 ohms
I sensor to F = 5 ohms
Bottom side:
H sensor to I = 5.8 ohms
I sensor to F = 3.5 ohms
The HV+ connection spot for the HFCB to the downstream capacitor pad on the Bus Cable 12.1
ohms.
1 Building PP1
2/13 Back plane resistance check
HV+ connection spot for the HFCB to the H sensor contact .6 ohms.
2/15 – elog 500 – bottom sensors placed and bonded
2/18 – elog 502 – bottom side 1900e
2/18 – elog 503 – top side 300e, bottom side 1900e, At the end of the run the temperature on
the top was ~41.5 C and the bottom was ~34.1 C. HV current was 0.5 uA.
2/18 – elog 507 – Bottom Sensor Backplane
Between HV tab on HFCB to H sensor backplane: ~21 Ohms
Between H and I sensor backplanes: ~4 Ohms
Between I and F sensor backplanes: bad connection, lowest seen 300 kOhms, but usually open
on one meter, 400 MOhms on a different meter
Between F sensor backplane and furthest pad (other side of capacitor): ~2 ohms for one side,
~5ohms for the other
Kludge wire to the F sensor.
Misc Connections
Between ground on L1C and end of module (one side of capacitor): ~0.6 Ohms
Top HV+ on HFCB to H sensor pad (after kludge): ~0.3 Ohms
2/19 – elog 513 – Measurements for the bottom side of the first module PP1 after kludging
the F sensor HV+ connection to the Hybrid bottom HV+ output pad:
HFCB Bottom HV+ to backing structure capacitor pad connecting to the F sensor = 2ohms
Backing structure (BS) capacitor pad to F sensor to the same capacitors pad connecting to the
mesh of the Bus Cable = 6.1M ohms.
Hybrid GND pad to BS cap pad connecting to Bus Cable mesh = .4 ohms.
2/19 – elog 514 – Bert added the kludge wire between the HFCB and far end of bus cable to
power the F sensor.
Applied 75V to bottom side, when run was started HV current was ~4.0 uA, ~2.6 uA after
finishing U3 and ~2.5 uA after run was complete.
U3 3500e, U4 3700e
2/19 – elog 515 - Bottom side HV+ tab to Bus Cable = .3 ohms
from HV+ to back of H sensor = ~ 21 ohms
Bus Cable HV+ Pad (Hybrid Connection) to H pad connection measured .6 ohms.
This isolates the resistance (21 ohms) to the silver epoxy connection.
2/19 – elog 517 - from HV+ on hybrid to the sensor backplane.
.6 Ohm from HYbrid to H
2.2 Ohm from Hybrid to I
5.6 Ohm from Hybrid to F
2/19 – elog 518 - top HV is drawing high current.
When ramping up the supply (which thus far has been set to 75V 40uA) the supply trips and
turns the channel off.
Reducing the voltage to 5V shows a ~25uA current draw.
~200 kOhms between HV+ and GND on the top side. After desoldering the kludge wire for the
top HV+ and measuring the wire directly it was down to ~6 kOhms. I inspected the underside of
the top sensors for glue migration and have found a possible spot that looks like silver epoxy
(going to have Greg/Bert confirm and see if there is anything that can be done about it).
After Greg removed the silver epoxy from the edge of the CF near the H sensor, the short
kludge wire was resoldered to the hybrid HV+ pad for the top side. Resistance between HV+
pad and GND is now 3.9M ohms. Current draw is improved, but still to high, 25V @ 12 uA.
2/21 – elog 525 - Bert tried cleaning the silver epoxy some more.
Its slightly worse than before in that its tripping the supply (40 uA limit) at 25V.
3/19 – elog 585 - tried to clean up the backing structure some, but to no avail the bottom still
trips (~15V @ 50uA).
1.1
Problems encountered/ Solutions undertaken
1.1.1 Pitch Adapter broke during HFCB tab removal, replaced
1.1.2 Bus cable bad contact, kludge wire, HV+ trace damaged, kludge wire
1.1.3 Silver epoxy squeeze out on top side, cleaning the epoxy
1.2
Symptoms after completion of module
1.2.1 Both sides draw high current (>40uA)
1.2.2 Kludge wires on the bus cable => high noise
1.3
Lessons learned to build next module
1.3.1 Changed assembly procedure to place PA during sensor placement instead of
during HFCB placement
1.3.2 Tighten control of the amount and position of silver epoxy during application
2 Building PP2
2/19 – elog 509 - Electrical measurements:
Top HV+ on HFCB to H sensor connection 1.6 ohms.
Top GND HFCB to Bus Cable cap pad connected to mesh .6 ohms.
HV+ to GND is open.
Bot HV+ on HFCB to H sensor connection .7 ohms.
Bot. GND HFCB to Bus Cable cap pad connected to mesh is .6 ohms.
HV+ to GND is Hi impedance (+11M ohms).
HV measurement on top is 73.6V. The inputs to top and bottom were both 75V at L1C.
2/19 – elog 510 – Both sides of HFCB 2P6 have been glued to the backing structure.
Both VDD are using sense wires set to 3V, while analog is set to 3.25V (no sense correction
~2.91V at the L1C). All channels are using regulators.
Currents:
Top VDDA: 0.315A
Top VDD: 0.166A
Bottom VDDA: 0.312A
Bottom VDD: 0.167A
All chips 300e
2/20 – elog 519 - Only bottom side silicon has been placed, only bond the H sensor on the
bottom side (H-I and I-F are unbonded).
only the bottom HV was applied (75V @ 0.1 - 0.2 uA).
All 4 chips passed a register test prior to running the gain scan.
U1/U2: 300e, U3/U4: 700e
2/20 – elog 520 - after Tammy bonded the H to I sensor.
applied HV to bottom: 75V @ 0.3uA
U1/U2: 300e, U3/U4: 1200e
2/20 – elog 521 - Tammy bonded between I and F, so now all the bottom sensors are
connected.
applied HV to the bottom: 75V @ 0.4uA
U1/U2: 300e, U3: 1700e, U4: 1800e
2/21 – elog 524 - now on the top side sensors.
Tammy bonded the H sensor.
All sides have HV at 75V: top 0.3 uA - bottom 0.4 uA
U1/U2: 700e, U3: 1800e, U4: 1900e
2/21 – elog 526 - We measured the overall length resistance for the sensor back planes (From
the HFCB HV+ pad on the top side of the HFCB to the capacitor pad on the Bus Cable which is
connected to the F sensor backplane thru two silver epoxy dots): Measurement was ~ 30M
ohms.
Hybrid Top HV+ pad to H sensor back plane = .9 ohms
Hybrid Top HV+ to the I sensor back plane = 32 ohms
Hybrid Top HV+ to the F sensor back plane = 11Mohms
Bottom side resistance measurements are:
H sensor backplane to I sensor backplane = 4.6ohms
I sensor backplane to F sensor backplane = 11 ohms
2/21 – elog 527 - Tammy bonded the I sensor.
HV (75V) was applied to top and bottom: both sides were 0.4 uA
U1/U2: 1200e, U3: 1800e, U4: 1900e
2/21 – elog 528 - Tammy bonded the F sensor and repaired a bond between the PA and H
sensor on U2 (the bond had broken at the foot on the PA side).
HV (75V) was applied to top and bottom: both sides were 0.5 uA
U1/U2: 1700e, U3: 1800e, U4: 1900e
2/21 – elog 530 - Bert added a wire for the F sensor.
HV (75V) was applied to top and bottom: both sides were 0.6 - 0.7 uA
U1: 1700e, u2: 1800e, u3: 2000e, u4:2200e
2/21 – elog 532 - removed the kludge wire and flipped the module over so that Bert could place
some silver epoxy between the H / I and I / F sensors.
After placing the epoxy we looked at it through the camera to verify that no epoxy had
migrated to the CF and there was a clear gap between the epoxy and the CF.
2/22 – elog 533 - After Bert put silver epoxy between H/I and I/F sensors. Done with module in
storage box with top side down.
75V on both top and bottom: initially top was drawing 6-9 uA by the end of the run it was 27-29
uA bottom side was drawing 0.9 uA.
U1: 2200-2800e, u2: 2800e, u3: 1600e, u4: 1700e
2/22 – elog 534 - Measured resistance of PP2 top side total back plane resistance = ~ 3 ohms
Resistance to GND = 2.77M ohms
After visual inspection silver epoxy kludge is not contacting the top side of the silicon.
3/4 – elog 547 - Resistance on top between H/I = 18.1 Ohms, I/F = 37.5 Ohms, HFCB HV+ - far
end of bus cable = 50.2 Ohms, HV+ and GND (HFCB) = 856 kOhms
Current draw on top at 75V bounced around from 15 - 20 uA prior to starting gain scan, after
being powered up for a few minutes.
Checked the bottom sensor backplanes: H/I: 4.9 Ohms, I/F: 46.2 kOhms (wasn't very
consistent). There is also a suspicious wire bond on the top side between I/F I think one of the
bias bonds might have come up
3/4 – elog 348 - Sometime during taking data for U4 the HV for the top tripped (limit set to 40
uA).
HV for the bottom was 0.7 uA at the end of the run.
U1/u2: 1700e, U3/U4: bad data, could not fit
3/6 – elog 554 – top side sensors damage pictures
3/12 – elog 559 - both sides are double digit MOhms between HV+ / HV- on L1C.
2.1
Problems encountered/ Solutions undertaken
2.1.1 Bad HV+ contact between sensor backplane and bus cable on top F sensor
2.2
Symptoms after completion of module
2.2.1 Top sensors damaged during silver epoxy removal and draw high current
2.3
Lessons learned to build next module
2.3.1 Add extra silver epoxy towards center of sensor for better contact
2.3.2 Kludge wire is picking up noise, use tape with silver epoxy, do not apply epoxy
only kludge
3 Building PP3
3/8 – elog 559 - Bottom
HV + -> H Sensor = 24 Ohms
HV+ -> I Sensor = 45 Ohms
HV+ -> F Sesnor 343 Ohms
These measurement hop around a bit do to the inability to get good contact with the bottom of
the mounted sensors
HV+ -> End 373 Ohms
HV+ -> GND 2.6 MOhms
Applied 5V for HV, current draw was ~25 uA
(3/12): Measured between HV+ and HV- on L1C with no cables attached: top was double digit
MOhms (and rising), bottom was ~200 kOhms.
3/11 – elog 561 - HFCB to H - 854 kOhms
H to I - 20.2 Ohms
I to F - 41.8 Ohms
F to Bus Cable Pad - 13.6 Ohms
3/14 – elog 569 - Desoldered the GND tabs on the HFCB that connect to the bus cable and
wrapped the tabs with kapton tape. However even after doing so there still was a resistance of
~700 kOhms between HFCB GND and the copper tab.
During the gain scan there was no data from U2. (broken wire in data cable)
U1: 1700-2000e, u3/u4: bad data
3.1
Problems encountered/ Solutions undertaken
3.1.1 Bad HV+ contact between sensor backplane and bus cable on top H sensor,
make a kludge (tape or wire between the back planes)
3.2
Symptoms after completion of module
3.2.1 Still bad sensor backplane connection
3.2.2 High current on the top side
3.3
Lessons learned to build next module
3.3.1 Need to modify bus cable, add rails for HV+
3.3.2 Need to identify the cause of high current draw
4 Building PP4
3/11 – elog 562 – added gold coated kapton strips for sensor HV+
3/12 – elog 563 – bottom sensors placed
u1/u2: 300e, u3 1700e, u4 1800e
3/13 – elog 564 - For top HV initially tried 30V @ 60 uA, but the PS tripped, lowered it to 25V.
For bottom HV its set at 85V since after looking at the sensor data from Hamamatsu that is the
highest full depletion voltage.
After the run was complete with the HV off the resistance between HV+ and HV- on the L1C
was 0.7 MOhms for top and 1.1 MOhms for bottom.
U1: 3400e, u2: 2200e, u3: 2000e, u4: 1700e
3/14 – elog 567 - GND tabs on HFCB have been desoldered
u1/u2: 1700e, u3/u4: 2000e
3/14 – elog 568 - Moved the module from the top wire bonding fixture to the storage box.
U3: bad data, u4: 2000e
3/15 – elog 570 - Attached water block to storage box
u1: 1600e, u2: 1700e, u3: 2000-2600e, u4: bad data
3/15 – elog 578 - Flipped module back over (top is facing plastic cover) and connected chiller
u1/u2: 1600e, u3: 1700-1900e, u4: 2000e
3/18 – elog 579 - Run this morning after having module powered over the weekend.
Current for top was ~10 uA prior to starting run.
U1/u2: 1600e, u3: 1700-1900e, u4: 2000e
3/18 – elog 580 - After fiddling with the GND tabs some more got the HV top current to be
more reasonable.
Top side up in the storage box.
Between U1 and U2 the data cable was changed from #3 to #5 due to a wire breaking and not
getting any data back on U2.
U1/u2: 1600e, u3: 2000-2500e, u4: 2600e
3/18 – elog 582 - Flipped module over so that top side is towards the AL plate and the bottom
side is towards the plastic cover
u1: 2200-3000e, u2: 3200e, u3: 1600e, u4: 1700e
3/21 – elog 599 – u1/u2: 1600e, u3: 2200-4000e
4.1
Problems encountered/ Solutions undertaken
4.1.1 Tried cleaning edge of bus cable / sensors
4.1.2 High current on HV top / tried removing bias bonds (not sensors) / removed HV
filter and direct connect HV to tabs (not HFCB)
4.2
Symptoms after completion of module
4.2.1 High current draw on top side due to bus cable
4.3
Lessons learned to build next module
4.3.1 Need to further isolate bus cable from sensors
5 Building PP5
3/19 – elog 583 - put a conductive plane on top of the bus cable (both sides tested the same
way). Applied HV and monitored current. Test passed.
3/20 – elog 592 - module flipped so that the bottom side is facing up.
U1/u2: 300e, u3: 1800-2000e, u4: 1800e
3/20 – elog 594 - Moved the module into a plastic box
u3: 1800-2500e, u4: 2000e
3/20 – elog 595 - Moved the plastic box onto a small table instead of the metal lab one
u3: 1700-2000e, u4: 1800e
3/20 – elog 596 - Moved module back into storage box with bottom side facing up and placed
on the small table.
U3/u4: 1700e
3/20 – elog 597 - with module installed in storage box normally (bottom down).
U3: 1700-2000e, u4: 2300e
3/21 – elog 600 - Done while still in the top sensor placement/wire bonding fixture.
U1/u2/u3/u4: 1700e
3/21 – elog 601 - Bert moved the module into a storage box.
U1: 1700e, u2: 1800e, u3: 2200-3200e, u4: bad data
3/21 – elog 602 - Attached some copper tape between the copper block and the storage box
u1/u2: 1700e, u3/u4: 1600e
3/21 – elog 604 - Attached water block to storage box and waited until HV current &
temperature stabilized before starting run.
U1/u2/u3/u4: 1600e
Current draw ~0.3 uA each side
5.1
Problems encountered/ Solutions undertaken
5.1.1 Noise is dependent on which side of module is facing AL storage box
5.2
Symptoms after completion of module
5.2.1 Working module
5.3
Lessons learned to build next module
5.3.1 Need to ground storage box
Mitigation plan based on experience during assembling the pre-production modules.




Bus cable:
o Switch from serial HV biasing scheme to the parrallel biasing
o Add gold/nickel plating of the HV pads
o Increase thickness of polyimide layer and add overlay
Backing structure:
o Remove tabs and ensure straight cut edge
o Add precision edge trimming step
o Use sanding and cleaning the edge
o Coat the edge with parylene
o Modify QC of backing structure (HV test and visual inspection)
o Procure additional flat plate for CF autoclave platen to increase CF layout cycling
efficiency
o Redesign BS mold
o Modify BS inspection plate to account for increased thickness
L1C:
o Incorporate shield grounding options
o Remove strain relief from L1C (move it to L1C support plate)
Module assembling:
o Change Pitch Adapter mounting procedure, mount PA during sensor placement







o Modify sensor placement procedure to remove vacuum after partial setting of
structural epoxy
o Make corrections to chip bonding diagrams
o Modify clamp on HFCB installation fixture
o Procure additional HFCB installation fixture to increase production rate
o Small revision to module holding plate for bottom sensor installation fixture
o New parts for sensor installation fixtures to up the fixture quantity
Rohacell:
o Modify dimensions to account for changes in backing structure
Carbon fiber:
o Modify the width of CF to fit the new backing structure profile
o Use CF with different resin
Copper insert:
o Modify thickness to account for increased thickness of backing structure
Storage:
o Modify HFCB storage box to improve edge clamping
o Ground module carrier box
o Modify module carrier box design
Inventory:
o Use common nembering scheme for modules and module components
Repairs:
o Test feasibility of replacing encapsulated chip
o Check possibility of pitch adapter repair by placing new PA on top of the
damaged one
o Procure wirebonding repair assembly fixture
Assembing procedures
o Finalize module assembling and QA/QC testing procedures