March 3 - 6, 2019 Mesa, Arizona Archive - TestConX · Performance HDI Platform Design Xiao-Ming Gao...
Transcript of March 3 - 6, 2019 Mesa, Arizona Archive - TestConX · Performance HDI Platform Design Xiao-Ming Gao...
March 3 - 6, 2019
Hilton Phoenix / Mesa Hotel Mesa, Arizona
Archive
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Material Differences - PCB MaterialsTestConX 2019Session 6B Presentation 1
March 3-6, 2019TestConX Workshop www.testconx.org
Coaxial Via-Based Microstrip Line for High Performance HDI Platform Design
Xiao-Ming Gao Intel Incorporation
Mesa, Arizona ● March 3 - 6, 2019
Material Differences - PCB MaterialsTestConX 2019Session 6B Presentation 1
March 3-6, 2019TestConX Workshop www.testconx.org
Agenda
Coaxial Via-Based Microstrip Line for High Performance HDI Platform Design 2
Applications of ground return via in high speed design Pros and cons of using ground return vias Coaxial via construction Design of coaxial via based microstrip line Application of coaxial via microstrip line Manufacturing process Summary
Material Differences - PCB MaterialsTestConX 2019Session 6B Presentation 1
March 3-6, 2019TestConX Workshop www.testconx.org
Application of Ground Return Vias in PCIe 16 Gb/s
Coaxial Via-Based Microstrip Line for High Performance HDI Platform Design 3
Ground vias outside PCIe connector
Material Differences - PCB MaterialsTestConX 2019Session 6B Presentation 1
March 3-6, 2019TestConX Workshop www.testconx.org
Application of Ground Return Vias in 25Gb/s Ethernet
Coaxial Via-Based Microstrip Line for High Performance HDI Platform Design 4
GND vias (Green) near SFP connector
Material Differences - PCB MaterialsTestConX 2019Session 6B Presentation 1
March 3-6, 2019TestConX Workshop www.testconx.org
Pros and Cons of Using Ground Return Vias
Coaxial Via-Based Microstrip Line for High Performance HDI Platform Design 5
Pros:o Minimize impedance discontinuities o Reduce noise and crosstalk to nearby signals o Improve EMI
Cons:o Cost extra spaceo Sometime prohibitive such as in some HDI designso Crosstalk isolation is limited
Material Differences - PCB MaterialsTestConX 2019Session 6B Presentation 1
March 3-6, 2019TestConX Workshop www.testconx.org
Coaxial Via Construction
Coaxial Via-Based Microstrip Line for High Performance HDI Platform Design 6
Signal
Signal
Power
Ground
Signal
Signal
Power
Ground
Ground wall
Standard via Coaxial via with ground wall
Material Differences - PCB MaterialsTestConX 2019Session 6B Presentation 1
March 3-6, 2019TestConX Workshop www.testconx.org
Design of Coaxial Via Based Microstrip Line
Coaxial Via-Based Microstrip Line for High Performance HDI Platform Design 7
Parameters:
Drill size: 16 mils Via pad: 24 milsAnti-pad: 32 milsTrace width: 5 milsTrace length: 100 mils
8 Layer PCB Stackup Parameters
Material Differences - PCB MaterialsTestConX 2019Session 6B Presentation 1
March 3-6, 2019TestConX Workshop www.testconx.org
3D Electromagnetic Modeling
Coaxial Via-Based Microstrip Line for High Performance HDI Platform Design 8
Standard via with GND return via Coaxial via
Material Differences - PCB MaterialsTestConX 2019Session 6B Presentation 1
March 3-6, 2019TestConX Workshop www.testconx.org
Insertion Loss Performance
Coaxial Via-Based Microstrip Line for High Performance HDI Platform Design 9
Standard via with GND return via Coaxial via (50mil drill size)
Material Differences - PCB MaterialsTestConX 2019Session 6B Presentation 1
March 3-6, 2019TestConX Workshop www.testconx.org
Coaxial Via Outer Wall Drill Size Sensitivity
Coaxial Via-Based Microstrip Line for High Performance HDI Platform Design 10
Insertion Loss (32mil drill size) Insertion Loss (40mil drill size)
Material Differences - PCB MaterialsTestConX 2019Session 6B Presentation 1
March 3-6, 2019TestConX Workshop www.testconx.org
Design of Coaxial Via Based Microstrip Line
Coaxial Via-Based Microstrip Line for High Performance HDI Platform Design 11
Parameters:
Drill size: 16 mils Via pad: 24milsAnti-pad: 32milsTrace width: 5milsTrace length: 100 mils
12 Layer PCB Stackup Parameters
Material Differences - PCB MaterialsTestConX 2019Session 6B Presentation 1
March 3-6, 2019TestConX Workshop www.testconx.org
3D EM Modelling of PCB Coaxial Via Crosstalk
Coaxial Via-Based Microstrip Line for High Performance HDI Platform Design 12
Top view Ports set up
Material Differences - PCB MaterialsTestConX 2019Session 6B Presentation 1
March 3-6, 2019TestConX Workshop www.testconx.org
Standard Vias with Ground Return Vias
Coaxial Via-Based Microstrip Line for High Performance HDI Platform Design 13
Top view Ports set up
Material Differences - PCB MaterialsTestConX 2019Session 6B Presentation 1
March 3-6, 2019TestConX Workshop www.testconx.org
Comparisons of Far End Crosstalk (FEXT)
Coaxial Via-Based Microstrip Line for High Performance HDI Platform Design 14
Standard via microstrip line FEXT Coaxial via microstrip line FEXT
Coaxial via microstrip FEXT is much lower than standard via
Material Differences - PCB MaterialsTestConX 2019Session 6B Presentation 1
March 3-6, 2019TestConX Workshop www.testconx.org
Application of Coaxial Via Based Microstrip Line
Coaxial Via-Based Microstrip Line for High Performance HDI Platform Design 15
Controller Device
Case 1: standard vias (yellow) with ground return vias (black)
Case 2: topology using coaxial vias
Controller Device
Material Differences - PCB MaterialsTestConX 2019Session 6B Presentation 1
March 3-6, 2019TestConX Workshop www.testconx.org
Simulation Assumptions
Coaxial Via-Based Microstrip Line for High Performance HDI Platform Design 16
Controller to DeviceCoupled channels
Single ended signalingTransmit signal rate is 10 Gb/sController to device two coupled data channelsTx 1 is the victim and Tx 2 is the aggressorEye diagrams are measured at Rx 1
Tx 1
Tx 2
Rx 1
Rx 2
FEXT
Material Differences - PCB MaterialsTestConX 2019Session 6B Presentation 1
March 3-6, 2019TestConX Workshop www.testconx.org
Receive Eye Diagram Margins
Coaxial Via-Based Microstrip Line for High Performance HDI Platform Design 17
Transmit data rate is at 10 Gb/s
Case 1: standard vias with GND vias Rx 1 timing margin is 52ps
Case 2: coaxial via microstrip lineRx 1 timing margin is 59ps
Material Differences - PCB MaterialsTestConX 2019Session 6B Presentation 1
March 3-6, 2019TestConX Workshop www.testconx.org
Coaxial Via Manufacturing Process
Coaxial Via-Based Microstrip Line for High Performance HDI Platform Design 18
Sequential lamination process: For internal layers:
o First step is to drill the larger outer via o Second step is to plate this larger through hole viao Third step is to fill the this hole with dielectric material
Construct the top and bottom layer with traces Add the top and bottom layers to internal layers and press
together Drill the smaller inner via from top to bottom layers Plate this smaller through hole via
Material Differences - PCB MaterialsTestConX 2019Session 6B Presentation 1
March 3-6, 2019TestConX Workshop www.testconx.org
Coaxial Via Manufacturing Process Demonstration
Coaxial Via-Based Microstrip Line for High Performance HDI Platform Design 19
Material Differences - PCB MaterialsTestConX 2019Session 6B Presentation 1
March 3-6, 2019TestConX Workshop www.testconx.org
Summary
Coaxial Via-Based Microstrip Line for High Performance HDI Platform Design 20
Coaxial via based microstrip line is space efficient Superior crosstalk isolation Improved eye diagram timing margins Compatible with current PCB manufacture process
Material Differences - PCB MaterialsTestConX 2019Session 6B Presentation 1
March 3-6, 2019TestConX Workshop www.testconx.org
Acknowledgements
Coaxial Via-Based Microstrip Line for High Performance HDI Platform Design 21
The author would like to thank Naveid Rahmatullah and John Kelbert for their support and feedbacks.