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Preface |
To the readers of this book
This book is the compilation of a series of eight
lectures on the "Introduction to Flexible Printed Wiring Board for Engineers"
appeared in the JPCA Journal from November 2001 issue to the June 2002 issue
with some modifications. The Japan Printed Circuit Association realized that
the flexible printed wiring board had been expanding its areas of applications
considerably but there were few introductory texts of the technology. They
came to me and asked in 2001 to write a series of lectures on the flexible
printed wiring board especially for young engineers who were to work in this
area but were novice to the technology.
I noticed as I was asked to prepare such a book that
there were many technical books on the rigid printed wiring boards that had
far more long history of technology development compared to the flexible
printed wiring board of almost half a century. I also noticed that there was
almost no guidebook or introductory book to the flexible board technology for
workers and engineers who were to come to this technology for the first time.
Chances for ordinary people to actually see the use of
a flexible board itself housed in a product may be very small as the board is
usually entirely hidden in the case of the product. And yet, the flexible
printed wiring board is very widely used in very many sophisticated products
of the present day such as cellular phones and digital video cameras as just a
few examples. Its application areas are expanding very rapidly these years.
The author believes this introductory textbook on the
technology of the flexible printed wiring board is what needed for the
industry and should be of significant support to many engineers in
understanding the essence of the technology. Comparisons are made in this
textbook when it is appropriate of the flexible board technology to that of
the rigid printed wiring board that has a long history and has a large market
of nearly ten-fold of the flexible board to assist understanding of the
technology.
This textbook is written for the new engineers to this
technology as I mentioned, however, this book should also be helpful to people
actually working with the flexible board to deepen understanding of the
technology and the materials they are dealing with.
I thank the Japan Printed Circuit Association for
providing me with the opportunity to prepare this textbook and also wish to
ask the readers to send your comments on this small textbook.
May, 2003
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Yukihiko Abe |
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Contents |
1. Flexible Printed Wiring Board (Flexible PWB)
1.1 Features and Applications of Flexible PWB
1.2 Comparison of Flexible PWB and Rigid PWB
2. Materials used in Flexible PWB
2.1 Materials to Construct Flexible PWB
2.1.1 From Conductor Pattern Formation to Cover-lay Process
2.1.2 Surface Treatment and Stiffener Adhesion
2.2 Flexible Copper Clad Laminate
2.3 Base Film
2.4 Copper foil
2.4.1 Electrolytic Copper Foil
2.4.2 Rolled Copper Foil
2.5 Cover-lay
2.5.1 Cover-film with Adhesive
2.5.2 Solder Resist
2.5.3 Photosensitive Resin
2.6 Surface processing of Conductor
2.6.1 Electroplating
2.6.2 Other Materials for Surface processing
2.7 Adhesives
2.7.1 Copper Clad Laminate (CCL) and Adhesive for Cover-film
2.7.2 Adhesives for Stiffener Film and Stiffener Board
2.8 Stiffener Film, Stiffener Board, and Others
2.9 Interlayer Connection
3. Structure of Flexible PWB
3.1 Single-sided Flexible PWB
3.2 Double-sided Flexible PWB
3.3 Multilayer Flexible PWB and Flexible-Rigid PWB
3.4 Features of Flexible PWB and its Structure
3.4.1 Structure of a Bend
3.4.2 Structure for Interlayer Conductor Connections for Double-sided and
Multilayer Flexible PWB
3.5Other Items related to Flexible PWB Structure
4. Design of Flexible PWB
4.1 Issues Required in Flexible PWB Design
4.2 Specifications Required to Flexible PWB
4.3 Product Design
4.3.1 Pattern Design
4.3.2 Pattern Design
4.4 Process Design
4.4.1 Size and Dimensional Precision of Flexible PWB related to External
Shape of a Product
4.4.2 Datum and Tooling Holes in relation to Component Layout
4.4.3 Conductor Pattern Formation
4.4.4 Cover-lay Process
4.4.5 Surface processing
4.4.6 Lamination of Stiffener Film and/or Stiffener Board
4.4.6.1 Stiffener Film
4.4.6.2 Stiffener Board
4.4.6.3 Other Considerations
4.4.7 Shaping
4.4.8 Other Jigs Needed
4.5 Design of Tools and Jigs
5. Fabrication Process of Flexible PWB
5.1 Pattern Formation
5.1.1 Screen-printing
5.1.2 Photographic Method
5.2 Cover-lay Process
5.2.1 Cover-film with Adhesive
5.2.2 Solder Resist
5.2.3 Photosensitive Resin
5.3 Surface processing
5.3.1 Plating
5.3.2 Solder Paste Process
5.3.3 Anti-Rusting
5,4 Reinforcement
5.5 Lamination of Stiffener Film and Stiffener Board
5.6 Machining and other supplementary Processes
5.6.1 Shaping
5.6.2 Supplementary Process
5.7Inspections and Test
6. Component Assembly to Flexible PWB
6.1 Miniaturization of Components and Flexible PWB
6.2 Flexible PWB and Surface Mount Technology
7. Quality of Flexible PWB
7.1 Quality Required for Flexible PWB
7.2 Specifications and Test Methods for Flexible PWB
7.3 Specifications for Visual Inspection of Flexible PWB
7.4 Other Issues
8. Issues and Future Prospect of Flexible PWB
8.1 Business Crossing National Borders
8.2 Environmental Issues
8.3 Toward Higher Packing Density
8.4 International Standards
8.5 Prepare to the Expansion of Market
8.6 Proposals to Fresh Engineers
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