1. Module 1: Introduction Topic 3: Interconnect Technology
OGI EE564
Howard Heck
© H. Heck 2008
Section 1.3

2. Where Are We? Introduction Transmission Line Basics Analysis Tools
Overview
Trends & Challenges
Interconnect Technology
Transmission Line Basics
Analysis Tools
Metrics & Methodology
Advanced Transmission Lines
Multi-Gb/s Signaling
Special Topics
© H. Heck 2008
Section 1.3

3. Printed Circuit Boards
Contents
Component Packaging
Passive Components
Connectors
Printed Circuit Boards
© H. Heck 2008
Section 1.3

4. Overview (add-in card) Components (Chip + Pkg) Connector PCB
(Motherboard)
(add-in card)
Connector
Source: Intel Corp.
© H. Heck 2008
Section 1.3

5. Overview – SOA Desktop Motherboard
Graphics Connector
Chipset
Microprocessor
Memory Slots
© H. Heck 2008
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6. Overview – SOA Desktop Motherboard
Memory Connectors
Chipset
Graphics Connector
Microprocessor
X48 chipset motherboard
© H. Heck 2008
Section 1.3

7. Packages house the silicon chips. They provide:
Component Packaging
Packages house the silicon chips. They provide:
Mechanical support
Heat removal
Environmental protection
Electrical signal & power connections (chip to PCB).
Heat Spreader
Silicon
Package
PCB
Soldered Connections
© H. Heck 2008
Section 1.3

8. Component Packaging
© H. Heck 2008
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9. Component Packaging
Source: Intel Corp.
© H. Heck 2008
Section 1.3

10. Example: Flip Chip Pinned Grid Array
Bottom
Top
Cross-section
© H. Heck 2008
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11. Medium Speed Package Electrical Models
Bond Wire
Trace
Pin / Land
Tie Bar L bw R
pin Z , t d tb
, L
, C
Die
Board
Source: Packaging Databook, Intel Corp
Today’s speeds demand that we use fully coupled 3D package models.
© H. Heck 2008
Section 1.3

12. Passive Components Resistors
Uses: termination for interconnect, pull up/down for static features
Variability: 5%, 2%, 1%
Chip resistors – 1 resistor per component
R-Packs – up to 4 resistors per small outline component
Resistor networks – more resistors per component
Lead inductance and package crosstalk can be important effects for high frequency applications.
Capacitors
Variability: 20%, 10%
Chip capacitors – used for high frequency (local) decoupling of power suppliers
Tantalum capacitors – used for bulk decoupling
At high frequencies, resistance and inductance of the packages must be included in the models.
© H. Heck 2008
Section 1.3

13. Sockets & Connectors Sockets connect packages to PCBs.
Connectors connect PCBs to PCBs.
Connection is mechanical between two metal surfaces.
DIMM connector
LGA775 Socket
PCI® Express
© H. Heck 2008
Section 1.3

14. Socket/Connector Electrical Models
These are simple models. Coupled models are frequently used for high performance applications. R
con Z
0con , t
dcon
Today’s speeds demand that we use fully coupled 3D connector models.
© H. Heck 2008
Section 1.3

15. Printed Circuit Boards
Function: provide electrical signal connections between components & deliver power to the components.
Material Set:
Construction:
Typically 4 to 6 layers (always an even number).
4 layer board: 2 signal, 2 power ($0.09/in2)
6 layer board: 4 signal, 2 power ($0.18-$0.24/in2)
Higher layer counts are available at higher cost.
© H. Heck 2008
Section 1.3

16. PCB Construction © H. Heck 2008 Section 1.3 Surface Mount Pad
Signal Trace
Via Land
Power Plane
Laminate (Dielectric)
Via Barrel
Solder Mask
Laminate (Resin)
Laminate (Glass)
Signal Trace
Power Plane
Solder Mask
© H. Heck 2008
Section 1.3

17. PCB Signal Layer D D W S G S © H. Heck 2008 Section 1.3 f 0.024" f
0.012" D 1
0.050" G
0.005" W
0.006" S 2
0.005" S 1
© H. Heck 2008
Section 1.3

18. PCB Vias
Vias make layer-layer connections by drilling holes and filling them with conductor material (copper).
They are used in chips, package, and boards.
Heat Spreader
Silicon
Package
PCB
Soldered Connections
© H. Heck 2008
Section 1.3

19. PCB Design Goals Function: All signals connected
Performance: Maximum operating frequency
Cost
Minimized technology requirements
Layer count
Board size
Relaxed width & spacing
Relaxed via size
Design for manufacturability
Component selection
Component placement
Trade routing
© H. Heck 2008
Section 1.3

20. Summary
Package electrical parameters are typically modeled with lumped circuit elements and transmission lines.
We will examine the effects of lumped elements later, and will account for them in our design project. We will also consider when transmission line models are required.
For high volume PCs, system designers use pervasive, low cost PCB solutions:
FR-4 material set
4 layer boards
5/5 or 6/6 mil trace/space wiring
4 boards per panel for motherboards
PCBs are used for motherboards, add-in cards, and CPU packages.
PCBs provide interconnect for high speed buses operating as high as 400 MHz/800 MT/s and beyond.
© H. Heck 2008
Section 1.3

21. References
Intel Packaging Databook, Intel Corporation, 2002,
Component Types Used for SMT, IBM Microelectronics Division, January 1994.
Surface Mount Design and Land Pattern Standard, IPC-SM-782, IPC, Revision A – August 1993.
R.R. Tummala, E.J. Rymaszewski (ed.), Microelectronics Packaging Handbook, Van Nostrand Reinhold, New York, 1989.
© H. Heck 2008
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22. Appendix: More Packages
Celeron® Processor Package
Celeron® Processor Cartridge
Pentium® Processor w/ MMX™ Package
850 Chipset Package
© H. Heck 2008
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23. Appendix: More Connectors
ISA
PCI
SLOT1
Memory DIMM
AGP
© H. Heck 2008
Section 1.3

24. Appendix: CPU Sockets
PGA370
© H. Heck 2008
Section 1.3