Area Array Probe Card Interposer - SWTest.org · 2017. 3. 26. · HP54120B Cobra Probe 500 Ohm...
Transcript of Area Array Probe Card Interposer - SWTest.org · 2017. 3. 26. · HP54120B Cobra Probe 500 Ohm...
6/4/01 IBM RESEARCH Page [1]
Area Array Probe Card Interposer
Raphael RobertazziIBM Research
6/4/01
6/4/01 IBM RESEARCH Page [2]
Outline
• Motivation:– Probe Cards for Testing Complex ICs in the
Developmental Stage.– Hand Wired Space Transformer Limitations.– Bandwidth / Power Supply Bypassing
for High Speed / High Current Parts.• Interposer Concept / Implementation.• Experimental Results.• Conclusions.
6/4/01 IBM RESEARCH Page [3]
Motivation• Developmental Testing of Complex ICs.
Space XFM Required.– Probe Cards Need to be Manufactured Quickly
(<12 weeks). Ceramic Modules Not an Option.– Membrane Probe Technology Still Too Immature
for Complex Area Arrays of Ports.– Needle Cards Unusable.
Only Viable Option is Hand WiredSpace Transformer / Cobra Probes
6/4/01 IBM RESEARCH Page [4]
Hand Wired Space Transformer Limitations
• Bandwidth < 600 MHz– Rise time > 2nS
• Current < 30 Amps• Prone to Net List Errors
6/4/01 IBM RESEARCH Page [5]
Requirements For Two ICs Under Development
• Microprocessor Part– More Than 7000 Ports.– Probe Card #1 Accessed 866 Ports.– Current Draw 100 Amps At Full Speed– Clock Line Bandwidth > 1GHz.
• Communications Part– 10 Gb/s Input Port– High Quality RF By Pass.– Power Net Diagnostics (Noise).
6/4/01 IBM RESEARCH Page [6]
Desirable Performance Enhancements
• High Speed I/O Lines ( 1-10 GHz and Beyond).
• High (100 Amp) Current Drive, More Power Pins, and Low Inductance By Pass.
• Power Grid Diagnostics.• Lithographic Implementation of the Power
Net.• Ability to Repair Nets.• Decreased Probe Card Fabrication Time.
6/4/01 IBM RESEARCH Page [7]
Cobra Probes
Head
Magnet Wire
SpaceXFM
Pogo Pin Pad
Substrate
Hand Wired Space Transformer Cobra Probecard
6/4/01 IBM RESEARCH Page [8]
Application of the Interposer
J971 COBRA HEAD
VESPAL SPACE TRANSFORMER
COBRA WRIRESPACE TRANSFORMER LEAD
NORMAL CONFIGURATION
WITH KAPTON INTERPOSERHIGH SPEED LINE
BUMP
VESPAL SPACE TRANSFORMER
J971 COBRA HEAD
BUMP
HIGH SPEED LINE
DETAIL
HIGH SPEED CONNECTOR
MICROSTRIP TRACE
6/4/01 IBM RESEARCH Page [9]
Interposer Features
By Pass Capacitor
(4-1)
VDD Plane
GND Plane
High Speed Line
Low Inductance Ground Connection for High Speed Line and Supply By Pass
Through Connection toWire Bundle
Port to Port Connection
Bump
Cobra Probe
Wire
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Interposer Photo(Standard Flex Process)
Through Connection
High Speed Line
VDD Plane
Kapton Substrate
6/4/01 IBM RESEARCH Page [11]
Interposer Photo(Micro-Via Flex Process)
Through Connection
VDD Plane
25 µm Via
Kapton Substrate
6/4/01 IBM RESEARCH Page [12]
Interposer Schematic
MicrostripTrace
SMBJack
Kapton SheetMounting Frame
6/4/01 IBM RESEARCH Page [13]
Interposer on Test System
6/4/01 IBM RESEARCH Page [14]
TDR Characterization
HP54120BCobra Probe
6/4/01 IBM RESEARCH Page [15]
TDR Results
2 nS/Div 500 pS/Div
TDR With Interposer Mounted,
τ = 250 pS.
TDR of J971 Cobra Card,
τ = 1.15 nS.
6/4/01 IBM RESEARCH Page [16]
TDT Characterization
HP54120B
Cobra Probe
500 Ohm Picoprobe
6/4/01 IBM RESEARCH Page [17]
TDT Results
500 pS/Div 500 pS/Div
TDT of Interposer Alone,
τ = 214 pS.
TDT of Interposer + Cobra Head,
τ = 246 pS.
6/4/01 IBM RESEARCH Page [18]
S - Parameter Characterization
HP8753BCobra Probe
50 Ohm ThroughQuartz Substrate
6/4/01 IBM RESEARCH Page [19]
S – Parameter Results
0 1 2 3 4 5 6
0.0
0.2
0.4
0.6
0.8
1.0
50%@0.65 GHz
Quartz Substrate Through50% @2.45 GHz
CPCI Installed Hand Wired Cobra Alone
S21
f (GHz)
6/4/01 IBM RESEARCH Page [20]
Cobra Head Bandwidth Estimates
0 1 2 3 4 5 6
0.2
0.4
0.6
0.8
1.0
(20/80) % Rise Time = 56 pS4 GHz BW
Estimated S21 For Cobra Head Correcting For Connector and Microstrip Losses
Cobra Head, Probe Separation 11 mils.
Extra
pola
ted
|S21
|
f (GHz)
6/4/01 IBM RESEARCH Page [21]
Interposer For Biasing
Current Injection
Current Collection
X-Section: About 225#36 Wires at 1 InchFor 1 Oz. Copper.
Kapton Interposer
Chip C4s
6/4/01 IBM RESEARCH Page [22]
Current Capacity
• #36 (5 mil) Magnet Wire = 19.6 Mils.– 350 Wires 6900 Mils.
• 1Oz Cu = 1.4 Mils Thick– @1 inch diameter 4400 Mils.
• Calculated Resistance = 0.19 mΩ, Injecting on a 10 Inch Circle and collecting On a 1 Inch Circle, for 1.8 µΩ−cm, 1 Oz. Copper.
1 Oz Plane Can Provide at Least 64% of the Capacity of a Large (350 wire) Power Net
6/4/01 IBM RESEARCH Page [23]
Bias Experiment
Current Injection, 10 Amps
Current Collection
Copper Plane On Interposer
2.3
2.5
2.7
8.54.83.1
Potential, mV
6/4/01 IBM RESEARCH Page [24]
Conclusion
• Demonstrated 4X Bandwidth Improvement Over Hand Wired Space XFM Alone.
• Bandwidth Limitation Gated by Connector, Not Cobra Head.
• Interposer Can Add Extra Current Supply Capacity and High Quality, Low Inductance By Pass Capacitance.
• Interposer Provides a Quick Repair / Reroute Capability for Probe Card.