Tape Casting: Theory and Practice

309 Pages·2000·20.196 MB·English

by  Richard E. Mistler, Eric R. Twiname

TAPEC ASTING
T H E O R Y A N D P R A C T I C E
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TAPEC ASTING
T H E O R Y A N D P R A C T I C E
Richard E. Mistler Eric R. Ih-iname
and
Published by The American Ceramic Society, 735 Ceramic Place, Westerville, OH 43081
The American Ceramic Society
735 Ceramic Place
Westerville, Ohio 4308 1
0 2000 by The American Ceramic Society.
All rights reserved. Published 2000.
Printed in the United States of America.
04 03 02 01 00 5 4 3 2 1
ISBN: 1-57498-029-7
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Contents
Preface .................................................. vii
Acknowledgments ......................................... ix
1. Introduction and History ....................... 1
2 . Materials Technology and Selection ............... 7
2.1 Powders ........................................... 7
2.2 Solvents ........................................... 15
2.3 Surfactants ........................................ 23
2.4 Binders ............................................ 37
2.5 Plasticizers ......................................... 45
2.6 Organic Interactions ................................. 56
3 . Materials Processing: Slip Preparation ............. 63
3.1 Prs-Batching Powder Preparation ....................... 63
3.2 Dispersion Milling ................................... 67
3.3 Plasticizer and Binder Mixing .......................... 72
3.4 Slip De-Airing ...................................... 77
3.5 Slip Characterization ................................. 79
4 .The Tape Casting Process ...................... 83
4.1 Equipment ......................................... 83
4.2 Physics and Procedures for Fluid Metering ................ 127
4.3 Drying ............................................ 152
5 . Further Tape Processing ........................ 187
5.1 Tape Characterization and Analysis ..................... 187
5.2 Shaping ........................................... 199
5.3 Calendering and Lamination ........................... 204
6 . Applications of Tape Technology .................2 09
6.1 Substrates ......................................... 209
6.2 Multilayered Ceramic Packages ......................... 210
6.3 Multilayered Ceramic Capacitors ....................... 213
6.4 Other Electrical and Electronic Components .............. 215
6.5 Fuel Cells for Power Generation ........................ 218
6.6 Functionally Gradient Materials ........................ 220
6.7 Separators for Batteries ............................... 221
6.8 Structure-Controlled Materials ......................... 221
6.9 Rapid Three-Dimensional Prototyping ...................2 22
6.10 Lithium Ion Batteries (Polymer Batteries) ................. 223
6.11 Brazing Alloys ...................................... 223
6.12 Thin Sheet Intermetallic Compounds ................... 224
7 . Water-Based (Aqueous) Processing ...............2 25
7.1 Water-Soluble Binders ................................ 228
7.2 Water-Emulsion Binders .............................. 232
7.3 Shared Concerns .................................... 236
Appendix 1. Model Formulations and Procedures ................ 239
Appendix 2 . Calculation for Theoretical Airflows to
Remain under the Lower Explosive Limit (LEL)
During Tape Casting in a Continuous Machine ....... 257
Glossary of Terms ......................................... 261
References ............................................... 279
Index ................................................... 293
Preface
F ifty years ago, Glenn Howatt first described the process known
today as tape casting? Although Howatt used this process to
manufacture millions of capacitors, the authors are convinced that
even in his wildest dreams, he did not foresee the impact of this
technology on the materials processing industry of today. Howatt’s
invention was born out of the urgent need to find a substitute for
mica as a capacitor material during World War 11. Tape casting has
matured into a full-blown manufacturing technique for the forma-
tion of thin, essentially two-dimensional sheets of just about any
material that can be produced as a powder. In today’s arena, this
includes products ranging from metallic electrodes for molten car-
bonate fuel cells to organic lithium polymer battery components
and the more common standard ceramic substrate materials. The
technology is even being used to manufacture three-dimensional
objects in a process known as LOM (laminated object manufactur-
ing), in which thin sheets are cut to different precision shapes by a
laser and laminated in a stack to fabricate a part. It appears that the
only limit to the utility of tape casting is the imagination of the
materials engineer.
This book is a compilation of ideas based upon experiment and
experience. Some portions are pure conjecture based upon our com-
bined 35 years of hands-on experience with tape castings. In many
ways, it is a how-to book that details our observations, interpreta-
tions, and solutions to specific problems. We hope that technicians,
engineers, engineering managers, professors, and students will all
benefit from reading this work.
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Acknowledgments
I would like to acknowledge the many contributions of the engi-
neers, scientists, and technicians with whom I have been associ-
ated during my 40 years of professional life. In particular I would
like to cite the personnel in the ceramics processing group at the
Western Electric Engineering Research Center, where I was first
exposed to the mysteries of tape casting. My coauthor, Eric
Twiname, deserves an accolade for keeping me honest during our
early-morning rap sessions, where many of the ideas put forth in
this book were conceived. He also convinced me that there was a
book to be written based upon this wealth of ideas. A very special
acltnowledgment goes to Dr. Harold Stetson, my mentor and good
friend, who introduced me to tape casting as a ceramics processing
technique more than 30 years ago. He took a very green novice sci-
entist under his wing and taught him the ropes about this process,
which eventually led to this book.
I would be remiss if I failed to acltnowledge my wife and life travel
companion, Elizabeth Brendel Mistler. Betty has wholeheartedly
supported me in this and in all of my pursuits and endeavors during
the 40 years we have been married. For this I will be forever grateful.
RICHARDE. MISTLER
YARDLEYPE, NNSYLVANIA
I would like to acknowledge Jesus Christ, my savior, without whom
naught would be; Dr. Daniel Rase, for making the manufacture of a
china coffee cup a topic of fascination one rainy summer afternoon-
it is not likely that the field of ceramic engineering would have
crossed my mind without that lesson. Also &chard Mistler, for a
loose hand in management, a patience to be envied, and the heart of
a true friend; and Harold Stetson for motivation and encouragement.
ERIC R. TWINAME
STATE COLLEGEPE, NNSYLVANIA