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©HDP User Group International, Inc. 1 Optical Interconnect Project Project Update M.Immonen, TTM Meadville, Shaoyong Xiang, Huawei For Member Meeting St Clara USA January 9, 2011 ©HDP User Group International, Inc. 1 Definition Stage Project
Transcript

©HDP User Group International, Inc. 1

Optical Interconnect Project

Project Update M.Immonen, TTM Meadville, Shaoyong Xiang, Huawei

For Member Meeting St Clara USA

January 9, 2011

©HDP User Group International, Inc. 1

Definition Stage Project

Background

• Increasing data rates in high-speed cards/backplanes

• Initiatives for serial signaling > 20 Gbps per lane over copper

interconnects – e.g. CEI 25G/28G VSR or IEEE 802.3ba 100G Cu

Backplane

• Some of the designs have board-to-board (B2B) signal reach

requirements of one meter through two sets of B2B connectors

• Significant increase in cost/ power consumption/ design efforts/

manufacturing challenges to achieve viable 20+ Gbps operation

• AOCs are becoming dominant for longer links (> 2m)

• Could fiber/waveguide interconnects mitigate some challenges?

• Maybe, if

• Providing very high speed or high bandwidth density

• Reducing power consumption

• Comparable cost

• Maturity, eco-system and proven reliability

©HDP User Group International, Inc. 2

Purpose

• Understanding performance benefits and limitations using

optical fibers and polymer waveguides for intra-system

interconnects on cards and backplanes

• Demonstrate backplane architecture that shows cost/

performance improvements obtained by using FO/WG links

• Focus on optical fiber/WG link characteristics, connectivity,

end-to-end link implementations and reliability of the same

• Use ―Black-box‖ approach, standardized components and

interfaces, be protocol-agnostic, focus on practical

solutions

©HDP User Group International, Inc. 3

Goals and Approach

• SoA survey of WG materials, parallel optical xceivers and

connectors available for short reach optical links

• Build verification TV (TV1) with multiple waveguide components

and FO/WG connects to examine practicality and link metrics

• Build a more complex system-level demonstration TV (TV2)

• Compare test results to equivalent electrical links and identify

design characteristics unique to optical signaling

• Assess optical backplane reliability using the TV constructions

with selected WG/FO designs, connectors and module packages

• Point out gaps and issues in design, fabrication, assembly and

testing to be addressed in the industry/ follow-on projects

• Provide robust technology building-blocks and best-practices for

System designers/ users/ providers

©HDP User Group International, Inc. 4

Out of Scope/ Project will not Provide

• Build application specific prototype(s)

• Solutions based on WDM or single mode fibers/WGs

• Wavelengths of 2nd and 3rd window

• Communication architectures other than point-to-point

• Need for multi-protocol module support

• Transceivers limited to mount at the card edge

• Chip-level photonic networks and Si-pho device

©HDP User Group International, Inc. 5

S.Xiang/Huawei,

B.Achir/Cisco,

M.Marino/Juniper,

C.Nodding/Boeing,

M.Brachmann/ALu,

D.Smith/NGC

B.Booth/OIL,

M.Immonen/TTM,

T.Shutter/Dow,

J.Rennie/API

R.Pitwon/Xyratex,

D.Richardson/Molex,

D.Rolston/Reflex Pho.

Sub-teams and Tasks

System Architecture and Specifications

• Optical intra-system link architectures

• Definition and specification of test vehicles

• Definition of optical layer interfaces and

signal launch

Design Architecture team

• Design practices for optical/electrical boards

Waveguide and fiber interconnects

• WG and FO materials and their data

• Optical waveguide processing and testing

Transceivers and Connectors

• Devices and connectors

• Data and link comparisons

©HDP User Group International, Inc. 6

Project Test Vehicles

• Verification Test Vehicle (TV1)

• Backplane with connector interfaces

• Used to verify design parameters and devices selected for TV2

• Basic TV, basic performance and reliability testing by the team

• Currently 3 available WG technologies to build TV1

• Specification and design must fit all WG technologies

• Design to include multiple WG components fitting realistic application targets

• Connector interfaces that can be used for performance testing and for

interfacing by OEMs and others to evaluate specific applications

• May want to include at least one daughter card with some kind of function on it

to test the backplane interface

• Must allow application/company specific tests and interoperability testing

• Demonstration Test Vehicle (TV2)

• Backplane with N Line Card(s) and M Switch Card(s)

• More difficult TV, Enhanced testing by the team

• Expanded specification challenging the technologies

• Connector interfaces that can be used for performance testing and for

interfacing by OEMs and others to evaluate specific applications

• Must allow application/company specific tests and interoperability testing

7

TV1 Concept

©HDP User Group International, Inc. 8

Group 1

Waveguides,

WG-Fiber

Interface

Group 3

Off-chip

Interface

Group 2

End-to-End

Links &

Connectors

A

B

C

Tx/Rx Tx/Rx

E F

G

Card1

N+N channels

Straight WGs, Inner Layer

Straight WGs, Surface Layer

Crossings Cascading bends D

Card2

H WGs + 90° Out-of-plane

Connector2

Connector1 Long waveguide spiral

90° -in-plane bends

1xN couplers

Butt-joint, 90-turn

TBD: Reference copper line designs, connector types (FO/FO; WG/FO; WG/WG)

9 ©HDP User Group International, Inc.

• Board

• Layout, construction, thickness, materials, size – TBD

• Optical layer: 3 polymer waveguide materials (OIL, Dow, API)

• Loss: < 0.1dB/cm; NA 0.2-0.28; 0.24; 0.37

• Core size: 35 µm and up, pitch: 250µm length: 0.15-1m

• End-facet: Butt-joint (90° turn?)

• Fibers: Standard OM3+ 50/125 GI MMF NA=0.2 12-ch fiber/ribbon;

High-NA large-core MMF (NA> 0.3; core > 70 µm)

• Transceivers and optical interface

• Fiber-pigtailed mid-board Optical Engines: available, provider TBD

• Available in 12x10G SMD modules

• Pre-aligned GaAs VCSEL/PDs, Driver, TIA/LA, control and

monitoring functions, FO interface: 50/125 MMF

• Fiber-less mid-board Optical Engines: available, provider TBD

• 4+4 ..12+12 I/O’s, free-space I/O to WGs

• Interface: Butt-couple or Integrated lens

• Connectors

• FO/FO MTP BP connector: orthogonal avail., 90° custom

• WG/FO connector: MT-based custom

• WG/WG BP connector: MT-based custom

TV1 BOM Optics

10

Optical Modules and Interface

©HDP User Group International, Inc. 11

Fibers

Nx12F

Fib

ers

Nx

12

F

E/O/E

conv.

Fib

ers

Nx

12

F

Fibers

Nx12F

E/O/E

conv.

1. Fiber-pigtailed Mid-board Parallel Optical Modules

Source: Hdpug Opto Project Parallel Optical Connector Technology Survey (Rev 020211)

• Optical I/O close IC

• Avoids long high-speed traces on PCB

• BGA/ LGA package with MT or top attached

optical connector

• 120 Gbps per module (12x10 Gbps Tx or Rx)

• Scalable e.g. 1 Tbps in 3 inch2 area

• Power: 45 mW per channel

On card On host module

Waveguides

E/O

conv.

Optical Modules and Interface, cont.

• Surface mountable optical

engines mounted to access

waveguides on board

• Butt-couple (free-space), no

need for 90-deg turn in WG

• Integrated lens array, need for

90-deg turn in WG

• 120 Gbps per module (12x10

Gbps Tx or Rx)

12

WG

/Fib

ers

2. Fiber-less Optical Modules

Testing Plan for TV1

©HDP User Group International, Inc. 13

Fabricate Boards

As-built Testing

Waveguides: IL, TL, RL, Eye 20 GHz, refractive index

Electrical: Impedance, S-parameters, Eye 20 GHz

Connectors: IL, RL, mate/unmate 200 cycles

Transceivers: Pout, Eye, BER

Link: IL, Eye, BER

TC -40/+85C

Link parts. System test In-situ monitoring of IL at established read points

Link BER, before/after

6x 260C

Reflow

Phase I tests to ensure waveguides and interfaces are practical

(or can be made so), they meet the specification Design envelopes for waveguide passive components – Loss vs.

length, size, ROC, # of crossings at NA’s 0.2-0.3

Connector parameters: IL, connector insertion force, # of insertions

before deterioration

Xceives and off-chip interface: Fiber-ended OE, Butt-joint OE

End-to-End Link losses: Macro loss budget

Other: Power vs. copper, functionality change vs. copper

Testing Plan

14 ©HDP User Group International, Inc.

HDPUG Optical Interconnect Project

Testing Plan

** Draft ** Last update 3.2.2011

Proposed Tests and Related Criteria for HDPUG Optical Interconnect TV1 and TV2 Test

Level TV1 TV2 Test Test Condition Test Specification Criteria (proposed) Pot. Owner

1 x Waveguide Transmission Loss IL for Lenght L1, L2. 850nm

1 x Waveguide Transmission Loss, post lamination IL for Lenght L1. 850nm

1 x Waveguide Bending Loss IL vs. ROC. Min. ROC 5mm

1 x Waveguide Cross-over Loss IL per Cross. Varying angles

1 x Waveguide Eye Pattern 12 Gbps, xx Gbps

1 x Waveguide Cross-talk

1 x Waveguide Dispersion

1 x Refractive Index Prism coupling. Core & clad

1 x MT Connector Insertion Loss 50/125 μm MM Fiber

1 x Link Loss (End-to-End)

1 x Link Eye Pattern 12 Gbps, xx Gbps

1 x BER ...40 Gbps

1 TDR Impedance trise=50 ps (10%-90%)

1 Near-end and Far-end Crosstalk trise= 50 ps (10%-90%)

1 Eye Pattern 6.25 Gbps, 12 Gbps, xx

Gbps

1 Insertion Loss 1 GHz to xx GHz

1 Return Loss 1 GHz to xx GHz

1 Propagation Delay

Unbiased Environmental Stress Tests

2 Solder Reflow Simulation 260C, 30 sec at temp, 6X

2 HTS (High Temperature Storage) 85°C or max storage T

2000h. Change in IL <

0.xx dB. Measurement

Intervals:

2 HTS (High Temperature Storage) - Connectors 85°C 168h.

2 LTS (Low Temperature Storage) -40°C or min storage T

2000h. Change in IL <

0.xx dB. Measurement

Intervals:

2 Thermal Shock (Alternative to HTS/LTS) -40°C/+70°C, 15mins dwell x

mins transfer, air-to-air 100 cycles

2 Thermal Shock (Alternative to HTS/LTS) -

Connectors -45/85°C 21 cycles, total 168h

2 HAST (Highly Accelerated Stress Test) 130°C, 0.23 MPa, 85%RH 96h

2 ATC (Accelerated Temperature Cycle) 0C-100C

..\Testing plan\HDPUG_Opto_Testing Plan_TV1_TV2_010211.xlsx

..\Testing plan\Testing Plan_270111.ppt

Waveguide Transmission Loss

15 ©HDP User Group International, Inc.

Optical Tests——WG Transmission loss

nm850

L2

L1

In-coupling fiber Multimode, 50/125um

Out-coupling fiber Multimode, diameter > WG

Optical Source

1 2T (IL IL ) /(L1 L2) (dB/cm)L

P10

P

out

in

IL Log

Backplane configuration Flat end to flat end

Measurement method IL: Insertion Loss

TL: Cut-back

Signalgenerator

Optical backplane

Optical TxDetector

/Oscilloscope

Fiberpatch cord

Opticalbackplaneconnector

TP1 TP2

Fiberpatch cord

System Test 1

(Tx/Conn/BP/Conn =>)

16 ©HDP User Group International, Inc.

1. Test optical power P1 (dBm) at TP1;

2. Test optical power P2 (dBm) at TP2;

3. Transmission Loss (dB) =P1-P2 Fiber

Conn Conn

System Test 2

(Tx/Conn/BP/Conn/Rx)

17 ©HDP User Group International, Inc.

Signal generator

Patch cord

Opticalbackplaneconnector

Optical Tx Optical Rx

Optical backplane

Patch cord

Error detectoror Oscilloscope

1. Eye diagram test

2. BER test Conn Conn

TV2 Scope and Tests

• Demonstration Test Vehicle (TV2)

• Optical communication test vehicle to evaluate application

of optical signaling to a multi-node compute system

• Signal reach up to 1 m board-to-board with two connectors

• Based on parallel multimode WG/fiber ribbon channels

• Data rate ≥12.5 Gbps per channel at 850 nm wavelength

• Key performance metrics – Link operating margins, power

efficiency, BWxL product, packaging density

• Measured link IL compared with estimated link margin (source

intensity, receiver sensitivity, IL of link comp’s)

• Results compared to equivalent metrics established for

conventional high-speed electrical signaling (Ref. lines in TV)

• Scalability of the construction is evaluated using

©HDP User Group International, Inc. 18

Demonstrator Architecture Proposals

19 ©HDP User Group International, Inc.

Optical cable path

(Jumper cable)

Optical waveguide (inside

backplane)

linecard

Mid-board

optical module

• The chassis is configured to use waveguides within the backplane, but route each line-card’s

optical i/o to the front panel.

• The line-card has a jumper cable to the top of the chassis

Optical conduit

(Extension cable)

Proposal 1. Optically Enhanced Backplane

Demonstrator Architecture Proposals

20 ©HDP User Group International, Inc.

Opticalconnector

Electricalconnector

Opticalchannel

Electricalchannel

line card

switch cardoptical waveguide

or fiberOE module

Opticalbackplane

Optical connector

Optical connector

O/E Module

O/E Module

Embedded waveguide

Embedded waveguide

Optical and electrical connector

Optical and electrical connector

backplane

Proposal 2A. Waveguide/Fiber Hybrid Backplane

Proposal 2B. Orthogonal Case

OE Module with Fiber I/Os or

direct interface to WGs

Optical

channel =

OF/WG

Polymer Waveguides

Optical channel

= OF/WG

Specification

©HDP User Group International, Inc. 21

Parameter Value

v0 (190510) v1 (250910) v2 (201010)

System

Optical Channels per Line Card -- 12 Tx + 12 Rx

(or 24 Tx + 24 Rx)

No. of Line Card -- 2

Optical Channels per Switch Card -- 24 Tx + 24Rx

(or 48 Tx + 48 Rx)

No. of Switch Card -- 1 2

OE module Date Rate per Channel 10 Gbps > 10 Gbps

Channels per Device 12 12 (or 24)

Waveguide channel

Waveguide Channel Length ≥30cm ≥30cm

Waveguide core dimension 50um x 50um 50um x 50um

Waveguide pitch 250um 250um or 125um

Waveguide Loss ≤0.1 dB/cm ≤0.1 dB/cm

Launch conditions Offset, over, under

Return Loss -15 dB

Optical Waveguide Layers 1 2

Optical Backplane Connector

Channels per Connector 1 x 12 2 x 12

Channel Pitch 250um 250um or 125um

Connector Coupling Loss ( include coupling loss between connector and waveguide )

≤3 dB ≤2 dB

Dimension(include housing) -- L x W x H (???)

System Loss per Link <10dB

Updated Project Schedule

22 ©HDP User Group International, Inc.

Project Task Who Complete

Planned

Completion

Date

Actual

Completion

Date

Status

Plan Project S.Xiang, M.Immonen Completed Revised 1/2/11

SoA Surveys - Polymer WGs/FO; Xceivers and Conn's B.Booth, R.Pitwon 15/2/2011 Draft published

Specification for TV1 & TV2 S.Xiang 28/2/2011 To be finalized

System architecture, optical layer interfaces and signal

launch TV1 and TV2

B.Achir, S.Xiang,

C.Noddings,

M.Marino

15/3/2011 Proposals out

WG mtrls and OE components to be tested in TV1 Team 15/3/2011 3 WG volunteers

Testing plan for TV1 & TV2 S.Xiang, B.Achir 15/3/2011 To be finalized

Optical/Electrical PCB design methodology D.Smith Waiting for proposal

Project to implementation phase M.Immonen 31/3/2011

TV1 Design 04/11

TV1 Board fabrication & opt. testing complete (WGs) 06/11

TV1 All components received 06/11

TV1 Board assembly 07/11

TV1 Optical and mechanical testing (FO, conn’s, links) 08/11

TV1 Reliability testing (T/C, HTOL,..) 10/11

TV1 Failure analysis + reporting 11/11

TV2 Final specification complete 01/12

TV2 Design 02/12

TV2 Board fabrication & testing complete 06/11

TV2 All components received 06/11

TV2 Board assembly 07/11

TV2 Optical and mechanical testing 08/11

TV2 Reliability testing 10/11

TV2 Failure analysis + reporting 11/11

Publish final report complete 10/12

Next Actions

• Finalize testing plan for TV1 (method, specific conditions)

• Finalize design specification and design features required

for TV1

• Agree board construction, materials (laminates, etc.),

optical components and connectors for TV1

• Identify resources (board design, fabrication, testing

sourcing CC) for TV1

• Commitments of team members

• Project to move into implementation

©HDP User Group International, Inc. 23

Interested Participants

©HDP User Group International, Inc. 24

Mailing lists status 09’10

– Fujitsu AT

– Hitachi

– Huawei

– IBM

– Isola Group

– Iteq

– ITRI

– Juniper

– TTM Meadville

– MMM

– Mayo Clinic

– Molex

– National Semic.

– Northrop Grumman

– Nokia Siemens

Network

– Optical Interlinks

– Oracle

– Park Electro

– Promex

– Purdue

– Reflex Photonics

– Rogers Corp

– Uta

– Wistron

– Xyratex

– Adamant

– Albemarle

– Alcatel-Lucent

– Atotech

– Boeing

– Celestica

– Cisco

– Conpart

– Dow

– Ericsson

– Flextronics

Contacts

©HDP User Group International, Inc.

Proprietary

25

• Jack Fisher (HDP User Group)

– Project Facilitator

[email protected]

• Marika Immonen (TTM Meadville, Finland)

– Project Leader

[email protected]

• Shaoyang Xiang (Huawei Technologies, China)

– Project Leader

[email protected]

• Marshall Andrews (HDP User Group) – Executive Director

[email protected]

Back up

©HDP User Group International, Inc. 26

Standardization Initiatives

27 Source: IEC 62658 Ed 1.0 Standardization Roadmap of

Optical Circuit Boards and Related Packaging Technologies

• IEC 62496, 62658, 62661 • IEC 62496-1 Optical Circuit Boards (12/08); 8 standards on performance,

measurements, interface and optical backplanes, and products specification as drafts

• De Facto Standards in Japan • 19 de-facto standards on optical circuit boards, optical backplanes, optical

connectors and optical modules on board (JPCA, Japan Electronics Packaging and

Circuits Association)

Conditions for Coupling

Fibre-Optic to Polymer Waveguides

©HDP User Group International, Inc. 28

Optical fibre connector

(e.g. MTP)

Optical fibre end facets

Optical waveguide end facets

Conditions for Coupling

Fibre-Optic to Polymer Waveguides

©HDP User Group International, Inc. 29

Input

waveguides

Output

waveguides

Fibre to polymer waveguide

1. Output Fibre N.A. ≤ (smaller or equal to)

Input Polymer WG N.A.

N.A. of conventional fibre ~ 0.2

N.A. of polymer waveguide ~ 0.25-0.3

2. Fibre Ø ≤ Waveguide Ø

Fibre core should fit

completely into

waveguide core

Polymer waveguide to fibre 3. Output Polymer WG N.A.

≤ Input Fibre N.A.

Acceptance

angles Acceptance

angles

4. Waveguide Ø <= Fibre Ø

Waveguide core

should fit completely

into fibre core

Input

waveguides

Output

Fibre

Output

waveguides

Input

Fibre

N.A. fibre ~ 0.2 < N.A. PWG ~ 0.3

NA condition not met NA condition qualified

Light Light

Example of FO/WG Interface

• Optical connector

(waveguide/Fiber)

must apply separate

design rules for in/out

channels

• Same applies for fiber-

ended transceivers

• Non-standard fibers

are used only for intra-

system links =>

external I/Os not

affected

©HDP User Group International, Inc. 30

Input

waveguides

Output

waveguides

Typical polymer waveguides

N.A. = 0.3

Core size = 50 μm x 50 μm

Output fibres

Low N.A. (e.g. 0.2)

Small core (e.g. 50 μm)

Standard 50/125 GI MMF

Input fibres

High N.A. (≥ 0.3)

Large core (≥ 71 μm)

Special fiber


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