HPK FPIX & BPIX sensor research summary at Purdue E. Alagoz
1, M. Bubna 1, A. Krzywda 1, K. Arndt 1, D. Bortoletto 1, I.
Shipsey 1, G. Bolla 1, S. Kwan 2, I. Osipenkov 3 1 Physics
Department, Purdue University, West Lafayette, IN, USA 2 Fermi
National Accelerator Laboratory, Batavia, IL, USA 3 Texas A&M
University, TX, USA 15 June 2012
Slide 2
Received FPIX and BPIX sensors HPK FPIX & BPIX sensors All
IVs measured @ T = 21 C for sensor quality check
Slide 3
PROBE STATION IV TESTS OF BARE HPK SENSORS @ T = 21 C
Slide 4
IV measurement scheme BPIX IV scheme FPIX IV scheme
Slide 5
FZ200N IVs FPIX FZ200N V breakdown ~ 450 V (all FPIXF sensors)
V breakdown ~ 850 V (all FPIXE sensors) BPIX FZ200N V breakdown ~
1000 V
Slide 6
FPIX MCZ200P IVs V breakdown ~ 600 V (all FPIXF_1 sensors) V
breakdown ~ 750 V (all FPIXF_2 sensors) 06_FPIXF_1: no breakdown
below 1000 V
Slide 7
BPIX MCZ200Y IVs No breakdown below 1100 V
Slide 8
FPIX FZ320P IVs V breakdown ~400 V Was this expected?
Slide 9
BPIX FZ320Y IVs V breakdown ~950 V
Slide 10
Summary & observations 52 HPK FPIX & BPIX sensors
received All sensor IVs measured @ T = 21 C IV data uploaded to CMS
database via BigBrowser Fluctuations observed in IVs: possible
reason can be poor contact between sensor and the probe chuck due
to sensor non-flat back surface Different breakdown voltages
observed for MCZ200P FPIX and FZ200N FPIX sensors Sensors will be
sent for bump bonding at Princeton
Slide 11
BUMP BONDING
Slide 12
Bump-bonding Processing at Princeton University Bump-bond
solder material is indium No reflowing applied, just mechanical
pressure applied after solder deposition to ROC bump-bond pads UBM
for silicon bump-bond pads Varying silicon-to-ROC interface
clearance but 8 m clearance reported by Princeton staff 5
prototypes produced so far
Slide 13
Spark area in the ROC Spark area in the Sensor First bump
bonded prototype Sensor (HPK_FZ_200N_06_BPIXA_1) arced below -300 V
Bump bonding: First prototype
Slide 14
Edge passivation HPK sensor coating With Parylene (N-type) at
room temperature at the Purdue Birck Nanotechnology Center 280 V
insulation per micron expected
Slide 15
Edge passivation Bump bonded prototypes glued and wire bonded
to on daughter cards on PCB test boards Checked ROC functionality
and sensor IV before coating Coating applied to the whole assembly
for simplicity and to avoid masking ROC wire bond pads sensor HV
pad on the backplane Two HPK and three FPIX bump bonded sensors in
the CVD chamber PCB Daughter card sensor
Slide 16
First MCZ prototype passivation Sensor
(HPK_MCZ_200Y_07_BPIXD_1) arced at -575 V Spark area in the sensor
Spark area in the ROC Coating: 2 um thick parylene
Slide 17
Two more MCZ 200P FPIX type HPK sensors were coated with 4
micron Parylene to achieve 1000 V with no arcing present assuming
280 V per micron of Parylene coating Both samples tested up to 800
V No arcing observed Readout chip functionalities are same as
before coating Parylene works well for passivation Coating: 4 um
thick parylene
Slide 18
SEM images taken for the sensor arced at 575 V after being
coated with 2 micron thick Parylene A good coating uniformity
observed Coating distributed everywhere on the sensor Coating: 4 um
thick parylene silicon Parylene coating
Slide 19
Coating: 4 um thick parylene Non-flat plateau and increase in
IV after coating needs to be investigated
Slide 20
Coating: 4 um thick parylene Non-flat plateau and increase in
IV after coating needs to be investigated
Slide 21
Bump bonding summary 5 sensors bump bonded (2xFZ200N, 3xMCZ)
First prototype burned due to arching Second prototype: ROC did not
work at all No serious ROC test before bonding 3 more prototype (2x
MCZ 200P and 1x FZ200N types) 1 MCZ200Y BPIX sensor tested in the
beam test 90% tracking efficiency with rotation Coated with 2 m
thick Parylene Arcing observed at 575 V 2x MCZ200P FPIX sensor
Coated with 4 m thick Parylene No arcing observed up to 800 V 1
prototype ROC is still functioning out of 5
Slide 22
Next Request Princeton to bump bond the rest of the sensors and
send to Purdue Send additional sensors at FNAL and Purdue to
Princeton No pre-assembling/no pre-coating testing Mask ROC
wire-bond pads and sensor HV pad with Sylgard 186 silicone rubber
or something similar Apply coating of 8 m thick Parylene (2000 V
insulation) Unmask ROC wire-bond pads and sensor HV pad Glue and
wire bond coated prototypes to PCB test boards No daughter card
will be used Checked post-coating ROC functionality and sensor IV
Check yield of bump-bonding and coating processes
Slide 23
Sent to Princeton 12x MCZ 200P FPIX 12x MCZ 200Y BPIX 1x FZ200N
FPIX 1x FZ200N BPIX Sent to FNAL 8x FZ200N BPIX 7x FZ200N FPIX Left
at Purdue 1x FZ200N BPIX 2x FZ200N FPIX 4x FZ320Y BPIX 4x FZ320
FPIX Final inventory Bump bonded 3x MCZ 200P FPIX 5x MCZ 200Y BPIX
1x FZ200N FPIX 1x FZ200N BPIX