IPC-7526-2007 模板和误印板清洗指南.pdf - 第5页

ｗｗｗ．ｂｚｆｘｗ．ｃｏｍ Table of Contents 1 INTRODUCTION ....................................................... 1 1.1 Scope ..................................................................... 1 1.2 Purpose .....................…

100%1 / 32
ｗｗｗ．ｂｚｆｘｗ．ｃｏｍ
Acknowledgment
Any document involving a complex technology draws material from a vast number of sources. While the principal members
of the Stencil Cleaning Task Group (5-31g) of the Cleaning and Coating Committee (5-30) are shown below, it is not pos-
sible to include all of those who assisted in the evolution of this standard. To each of them, the members of the IPC extend
their gratitude.
Cleaning and Coating
Committee
Stencil Cleaning
Task Group
Technical Liaisons of the
IPC Board of Directors
Chair
Douglas O. Pauls
Rockwell Collins
Chair
Mike Bixenman
Kyzen Corporation
Peter Bigelow
IMI Inc.
Sammy Yi
Flextronics International
Stencil Cleaning Task Group
Constantino J. Gonzalez, ACME
Training & Consulting
Charles Dal Currier, Ambitech Inc.
Ron Rumrill, C.I.D., Aqueous
Technologies Corporation
Steve Stach, Austin American
Technology
Glenn Dody, Dody Consulting
Robert Nelson, Dow Corning
Corporation
Victor P. Balasbas, Jr., Electronic
Assembly Services
Kantesh Doss, Ph.D., Intel
Corporation
Leland Woodall, Keihin Carolina
System Technology
Meng-Swen Chew, Kingston
Technology Company, Inc.
Charles M. Pitarys, Kyzen
Corporation
Mike Bixenman, Kyzen Corporation
Jack Reinke, Kyzen Corporation
Kathy Jenczewski, MicroScreen, LLC
Holly Wise, MicroScreen, LLC
Jing Qi, Motorola Inc.
William A. Rasmus, Jr., Northrop
Grumman Space Systems
Christine Fouts, Ph.D., Petroferm Inc.
Kevin W. Ham, PMR Systems,
Incorporated
Jim Evans, PresSure Products
Company, Inc.
William C. Schreiber, Smart Sonic
Corporation
Alden C. Johnson, Speedline
Technologies, Inc.
Michael Kasper, Vliesstoff Kasper
GmbH
Harald Wack, ZESTRON America
John R. Sanders, Zyvex Corporation
IPC-7526 February 2007
ii
标准分享网 www.bzfxw.com 免费下载
ｗｗｗ．ｂｚｆｘｗ．ｃｏｍ
Table of Contents
1 INTRODUCTION ....................................................... 1
1.1 Scope ..................................................................... 1
1.2 Purpose .................................................................. 1
1.3 Overview ............................................................... 1
1.4 Problem Statement ................................................ 1
1.5 Common Production Problems ............................. 1
2 BIBLIOGRAPHY OF DOCUMENTS,
SPECIFICATIONS AND REFERENCES .................... 4
2.1 IPC ......................................................................... 4
2.2 Joint Industry Standards ....................................... 4
2.3 American Standards for Testing Materials ........... 4
2.4 Federal Laws and Standards ................................. 4
2.5 Department of Defense ......................................... 4
2.6 Occupational Safety and Health Administration .. 4
2.7 Environmental Protection Agency (EPA) ............. 4
2.8 Department of Transportation ............................... 4
2.9 National Fire Protection Association (NFPA) ...... 4
2.9.1 Air Quality Management Standards (AQMD) ..... 4
3 STENCIL CLEANING PROCESS ............................. 4
3.1 Objectives for the Cleaning Process .................... 4
3.2 Substrate ................................................................ 5
3.3 Tools ...................................................................... 5
3.4 Pallets .................................................................... 5
4 MISPRINTED CIRCUIT BOARD CLEANING ........... 5
4.1 Solder Paste ........................................................... 5
4.2 Adhesives .............................................................. 6
4.3 PCB Cleaning Process Considerations ................. 6
5 CONTAMINANT TYPES AND REMOVAL
CHARACTERISTICS ................................................. 7
5.1 Polar Residues ....................................................... 7
5.2 Nonpolar Water Soluble Residues ........................ 7
5.3
Nonpolar Water Insoluble Residues ..................... 7
5.4
Nonreflowed Solder Paste .................................... 7
5.5
Reflowed Flux Residue ......................................... 7
5.6
Uncured (Wet) SMT Adhesive ............................. 7
5.7
Insoluble Residues ................................................ 7
6 STENCIL CLEANING PROCESSES ........................ 8
6.1
Under Stencil Wiping Process .............................. 8
6.2
Manual Stencil Cleaning ...................................... 8
6.3
Semimanual Stencil Cleaning ............................... 9
6.4
Single Chamber Equipment .................................. 9
6.5
Ultrasonic Agitation .............................................. 9
6.6 Automated Ultrasonic Stencil Cleaning ............... 9
6.7 Rotating Wand/Fixed Nozzle Spray-In-Air
Cleaning .............................................................. 10
6.8 Automated Ultrasonic Sponge Stencil
Cleaning .............................................................. 10
6.9 Multifunctional Batch System for Stencils,
Boards, and Maintenance Cleaning .................... 10
7 CLEANING CHEMISTRY OPTIONS ...................... 10
7.1 Cleaning Chemistry Selection ............................ 10
7.2
Chemistry Choices and the Cleaning Process ... 10
7.3
Solvent Cleaning ................................................. 11
7.4
Aqueous Cleaning ............................................... 11
7.5
Semiaqueous ........................................................ 12
8 CLEANING PROCESS CONSIDERATIONS .......... 12
8.1 Common Rules that Center on Aqueous
Cleaning .............................................................. 12
8.1.1
Temperature ......................................................... 12
8.1.2
Energy ................................................................. 12
8.1.3
Solvency/Concentration ...................................... 12
8.1.4
Time ..................................................................... 12
8.1.5
Cleanliness .......................................................... 13
8.2
Drying .................................................................. 13
9 EQUIPMENT ACCESSORIES .................................. 13
9.1
Equipment Accessories ....................................... 13
9.2
Process Control Accessories ............................... 13
9.3
Operation Accessories ......................................... 13
9.3.1
Pumps .................................................................. 13
9.3.2
Heaters ................................................................. 13
9.3.3
Filters ................................................................... 14
9.3.4
Dryers .................................................................. 14
9.3.5
Ion Exchange and Carbon Media ....................... 14
9.3.6
Evaporators .......................................................... 14
9.3.7
Exhaust/Venting Systems .................................... 14
9.3.8
Cooling Coils ...................................................... 14
9.3.9
Fixture/Basket Accessories ................................. 14
9.4 Compatibility Constraints with Cleaning
Solutions .............................................................. 15
10 ENVIRONMENTAL ................................................ 15
10.1
Air Emissions ...................................................... 15
10.2
Wastewater .......................................................... 15
10.3
Solid Waste ......................................................... 16
APPENDIX A Terms and Definitions ..................... 17
February 2007 IPC-7526
iii
ｗｗｗ．ｂｚｆｘｗ．ｃｏｍ
Figures
Figure 1-1 Cleaning Stencil Bottom .................................... 1
Figure 1-2 Solder Paste Buildup on Walls of Stencil
Apertures ........................................................... 2
Figure 1-3 Solder Paste Buildup on Walls of Stencil
Apertures ........................................................... 2
Figure 1-4 Open or Insufficient Solder Joints ..................... 2
Figure 1-5 Solder Balls Following Solder Reflow ............... 2
Figure 1-6 Bridging or Poorly Defined Solder
Paste Printing .................................................... 3
Figure 1-7 Failure to Place the Stencil on a
Level Plane ........................................................ 3
Figure 1-8 Variations in Solder Mask Thickness................. 3
Figure 1-9 Inconsistent Component Land Width ................ 3
Figure 1-10 Misaligned Stencil.............................................. 3
Tables
Table 4-1 Process Recommendations for Misprinted
PCBs with Different Types of Contaminants........ 6
Table 7-1 Cleaning Chemistry Selection Guide ................. 11
IPC-7526 February 2007
iv
标准分享网 www.bzfxw.com 免费下载