IPC-7095C-2013.pdf - 第7页

Table of Contents 1 SCOPE ...................................................................... 1 1.1 Purpose ................................................................. 1 1.2 Intent ..............................…

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Guy Ramsey, R & D Assembly
Teresa Rowe, AAI Corporation
Robert Rowland, RadiSys
Corporation
Manny Sanchez, Boeing Company
Christopher Sattler, AQS - All
Quality & Services, Inc.
Martin Scionti, Raytheon Missile
Systems
Sundar Sethuraman, Jabil Circuit,
Inc.
Gilbert Shelby, Raytheon Systems
Company
Jeff Shubrooks, Raytheon Company
Dana Smith, Lockheed Martin
Missiles & Fire Control
Vern Solberg, Solberg Technical
Consulting
Kerry Spencer, Lockheed Martin
Missile & Fire Control
Gregg Stearns, Emerson Climate
Technologies- Retail Solutions
Kristen Troxel, Hewlett-Packard
Company
Sharon Ventress, U.S. Army Aviation
& Missile Command
Joe Vo, Broadcom Corporation
Bill Vuono, Raytheon Company
Girish Wable, Jabil Circuit, Inc. (HQ)
Clint Wenthur, Plexus Manufacturing
Solutions - Neenah 1
Dewey Whittaker, Honeywell Inc. Air
Transport Systems
Bob Willis, The SMART Group
Linda Woody, Lockheed Martin
Missile & Fire Control
Fonda Wu, Raytheon Company
Michael Yuen, Foxconn
CMMSG-NVPD
Gil Zweig, Glenbrook Technologies
Inc.
A special note of thanks goes to the following individuals for their dedication to bringing this project to fruition. We
would like to highlight those individuals who made major contributions to the development of this standard.
Dudi Amir, Intel Corporation
Raiyomand Aspandiar, Intel
Corporation
Elizabeth Benedetto, Hewlett-Packard
Company
Scott Buttars, Intel Corporation
Michael Green, Lockheed Martin
Space Systems Company
David Hillman, Rockwell Collins
Bruce Hughes, U.S. Army Aviation &
Missile Command
Jennie Hwang, H-Technologies
Group
Karen McConnell, Northrop
Grumman Corporation
Ray Prasad, Ray Prasad Consultancy
Group
Jagadeesh Radhakrishnan, Intel
Corporation
Robert Rowland, RadiSys
Corporation
Vern Solberg, Solberg Technical
Consulting
Kristen Troxel, Hewlett Packard
Company
Linda Woody, Lockheed Martin
Missile & Fire Control
Front and back cover photos courtesy of Wavelength Electronics and Neuralynx
IPC-7095C January 2013
iv
Copyright IPC-Association Connecting Electronics Industries
Provided by IHS under license with IPC
Not for Resale
No reproduction or networking permitted without license from IHS
--`,,```,,,,````-`-`,,`,,`,`,,`---
Table of Contents
1 SCOPE ...................................................................... 1
1.1 Purpose ................................................................. 1
1.2 Intent .................................................................... 1
2 APPLICABLE DOCUMENTS .................................... 1
2.1 IPC ....................................................................... 1
2.2 JEDEC .................................................................. 2
3 SELECTION CRITERIA AND MANAGING BGA
IMPLEMENTATION
................................................... 2
3.1 Description of Infrastructure ............................... 3
3.1.1 Land Patterns and Circuit Board
Considerations ...................................................... 3
3.1.2 Technology Comparison ...................................... 5
3.1.3 Assembly Equipment Impact .............................. 8
3.1.4 Stencil Requirements ........................................... 8
3.1.5 Inspection Requirements ..................................... 9
3.1.6 Test ....................................................................... 9
3.2 Time-to-Market Readiness .................................. 9
3.3 Methodology ........................................................ 9
3.4 Process Step Analysis .......................................... 9
3.5 BGA Limitations and Issues ............................... 9
3.5.1 Visual Inspection ............................................... 10
3.5.2 Moisture Sensitivity ........................................... 10
3.5.3 Thermally Unbalanced BGA Design ................ 10
3.5.4 Rework ............................................................... 11
3.5.5 Cost .................................................................... 11
3.5.6 Availability ......................................................... 12
3.5.7 Voids in BGA ..................................................... 12
3.5.8 Pad Cratering ..................................................... 12
3.5.9 Standardization Issues ....................................... 12
3.5.10 Reliability Concerns .......................................... 13
3.5.11 Drivers for Lead-Free Technology .................... 14
4 COMPONENT CONSIDERATIONS ........................ 14
4.1 Semiconductor Packaging Comparisons and
Drivers ................................................................ 14
4.1.1 Package Feature Comparisons ........................... 14
4.1.2 BGA Package Drivers ....................................... 15
4.1.3
Cost Issues ......................................................... 15
4.1.4
Component Handling ......................................... 15
4.1.5
Thermal Performance ........................................ 17
4.1.6
Real Estate ......................................................... 17
4.1.7
Electrical Performance ....................................... 17
4.1.8
Mechanical Performance ................................... 17
4.2
Die Mounting in the BGA Package .................. 17
4.2.1 Wire Bond .......................................................... 18
4.2.2 Flip Chip ............................................................ 19
4.3 Standardization ................................................... 19
4.3.1 Industry Standards for BGA .............................. 19
4.3.2 Ball Pitch ........................................................... 20
4.3.3 BGA Package Outline ....................................... 21
4.3.4 Ball Size Relationships ...................................... 21
4.3.5 Package-on-Package BGA ................................. 22
4.3.6 Coplanarity ......................................................... 22
4.4
Component Packaging Style Considerations .... 23
4.4.1
Solder Ball Alloy ............................................... 23
4.4.2
Ball Attach Process ............................................ 24
4.4.3
Ceramic Ball Grid Array ................................... 24
4.4.4
Ceramic Column Grid Arrays ........................... 25
4.4.5
Tape Ball Grid Arrays ....................................... 25
4.4.6
Multiple Die Packaging ..................................... 25
4.4.7
System-in-Package (SiP) ................................... 26
4.4.8
3D Folded Package Technology ........................ 27
4.4.9
Ball Stack, Package-on-Package ....................... 27
4.4.10
Folded and Stacked Packaging Combination ... 28
4.4.11
Package-on-Package .......................................... 28
4.4.12
Benefits of Multiple Die Packaging .................. 28
4.4.13 Solutions for Very Fine Pitch Array
Packaging ........................................................... 28
4.5
BGA Connectors and Sockets ........................... 29
4.5.1 Material Considerations for BGA
Connectors ......................................................... 29
4.5.2 Attachment Considerations for BGA
Connectors ......................................................... 29
4.5.3
BGA Materials and Socket Types ..................... 30
4.5.4 Attachment Considerations for BGA
Sockets ............................................................... 30
4.6
BGA Construction Materials ............................. 31
4.6.1
Types of Substrate Materials ............................. 31
4.6.2
Properties of Substrate Materials ...................... 33
4.7
BGA Package Design Considerations ............... 33
4.7.1
Power and Ground Planes ................................. 33
4.7.2
Signal Integrity .................................................. 34
4.7.3 Heat Spreader Incorporation Inside the
Package .............................................................. 34
4.8 BGA Package Acceptance Criteria and
Shipping Format ................................................ 34
4.8.1
Missing Balls ..................................................... 34
4.8.2
Voids in Solder Balls ......................................... 34
January 2013 IPC-7095C
v
Copyright IPC-Association Connecting Electronics Industries
Provided by IHS under license with IPC
Not for Resale
No reproduction or networking permitted without license from IHS
--`,,```,,,,````-`-`,,`,,`,`,,`---
4.8.3 Solder Ball Attach Integrity .............................. 35
4.8.4 Package and Ball Coplanarity ........................... 35
4.8.5 Moisture Sensitivity (Baking, Storage,
Handling, Rebaking) .......................................... 36
4.8.6 Shipping Medium (Tape and Reel, Trays,
Tubes) ................................................................. 37
4.8.7 Solder Ball Alloy ............................................... 37
5 PRINTED BOARDS AND OTHER MOUNTING
STRUCTURES
........................................................ 37
5.1 Types of Mounting Structures ........................... 37
5.1.1 Organic Resin Systems ...................................... 37
5.1.2 Inorganic Structures ........................................... 37
5.1.3 Layering (Multilayer, Sequential or
Build-Up) ........................................................... 37
5.2 Properties of Mounting Structures .................... 37
5.2.1 Resin Systems .................................................... 37
5.2.2 Reinforcements .................................................. 38
5.2.3 Laminate Material Properties ............................ 39
5.3 Surface Finishes ................................................. 40
5.3.1 Hot Air Solder Leveling (HASL) ..................... 41
5.3.2 Organic Surface Protection (Organic
Solderability Preservative) OSP Coatings ........ 42
5.3.3 Noble Platings/Coatings .................................... 42
5.4 Solder Mask ....................................................... 46
5.4.1 Wet and Dry Film Solder Masks ...................... 46
5.4.2 Photoimageable Solder Masks .......................... 47
5.4.3 Jettable Solder Mask ......................................... 47
5.4.4 Registration of Board to Panel Image for
Solder Mask ....................................................... 47
5.4.5 Via Protection .................................................... 47
5.5 Thermal Spreader Structure Incorporation
(e.g., Metal Core Boards) .................................. 48
5.5.1 Lamination Sequences ....................................... 48
5.5.2 Heat Transfer Pathway ...................................... 48
6 PRINTED CIRCUIT ASSEMBLY DESIGN
CONSIDERATION ................................................... 50
6.1 Component Placement and Clearances ............. 50
6.1.1
Pick and Place Requirements ............................ 50
6.1.2
Repair/Rework Requirements ............................ 50
6.1.3
Global Placement ............................................... 51
6.1.4 Alignment Legends (Silkscreen, Copper
Features, Pin 1 Identifier) .................................. 51
6.2
Attachment Sites (Land Patterns and Vias) ...... 52
6.2.1
Big vs. Small Land and Impact on Routing ..... 52
6.2.2 Solder Mask vs. Metal Defined Land
Design ................................................................ 52
6.2.3
Conductor Width ................................................ 53
6.2.4
Via Size and Location ....................................... 54
6.3 Escape and Conductor Routing Strategies ........ 54
6.3.1 Escape Strategies ............................................... 57
6.3.2 Surface Conductor Details ................................. 58
6.3.3 Dog Bone Through Via Details ........................ 58
6.3.4 Design for Mechanical Strain ........................... 58
6.3.5 Uncapped Via-in-Pad and Impact on
Reliability Issues ................................................ 59
6.3.6 Fine Pitch BGA Microvia in Pad Strategies ..... 60
6.3.7 Power and Ground Connectivity ....................... 61
6.4 Impact of Wave Solder on Top Side BGAs ..... 61
6.4.1 Top Side Reflow ................................................ 61
6.4.2 Impact of Top Side Reflow ............................... 61
6.4.3 Methods of Avoiding Top Side Reflow ............ 62
6.4.4 Top Side Reflow for Lead-Free Boards ............ 64
6.5 Testability and Test Point Access ...................... 64
6.5.1 Component Testing ............................................ 64
6.5.2 Damage to the Solder Balls During Test and
Burn-In ............................................................... 64
6.5.3 Bare Board Testing ............................................ 65
6.5.4 Assembly Testing ............................................... 66
6.6 Other Design for Manufacturability Issues ....... 68
6.6.1 Panel/Pallet Design ............................................ 68
6.6.2 In-Process/End Product Test Coupons .............. 68
6.7 Thermal Management ........................................ 69
6.7.1 Conduction ......................................................... 70
6.7.2
Radiation ............................................................ 70
6.7.3
Convection ......................................................... 70
6.7.4
Thermal Interface Materials .............................. 71
6.7.5
Heat Sink Attachment Methods for BGAs ....... 72
6.8
Documentation and Electronic Data Transfer ... 73
6.8.1
Drawing Requirements ...................................... 74
6.8.2
Equipment Messaging Protocols ....................... 74
6.8.3
Specifications ..................................................... 75
7 ASSEMBLY OF BGAS ON PRINTED CIRCUIT
BOARDS
................................................................. 76
7.1
SMT Assembly Processes .................................. 76
7.1.1
Solder Paste and Its Application ....................... 76
7.1.2
Component Placement Impact ........................... 78
7.1.3
Vision Systems for Placement ........................... 78
7.1.4
Reflow Soldering and Profiling ......................... 79
7.1.5
Material Issues ................................................... 84
7.1.6
Vapor Phase ....................................................... 84
7.1.7
Cleaning vs. No-Clean ...................................... 84
7.1.8
Package Standoff ............................................... 85
7.2
Post-SMT Processes .......................................... 86
7.2.1
Conformal Coatings ........................................... 86
IPC-7095C January 2013
vi
Copyright IPC-Association Connecting Electronics Industries
Provided by IHS under license with IPC
Not for Resale
No reproduction or networking permitted without license from IHS
--`,,```,,,,````-`-`,,`,,`,`,,`---