This is a book about the integrity of sealed packages to resist foreign gases and liquids penetrating the seal or an opening (crack) in the packageùespecially critical to the reliability and longevity of electronics. The author explains how to predict the reliability and the longevity of the packages based on leak rate measurements and the assumptions of impurities. Non-specialists in particular will benefit from the author's long involvement in the technology. Hermeticity is a subject that demands practical experience, and solving one problem does not necessarily give one the background to solve another. Thus, the book provides a ready reference to help deal with day to day issues as they arise. The book gathers in a single volume a great many issues previously available only in journalsùor only in the experience of working engineers. How to define the ""goodness"" of a seal? How is that seal measured? How does the integrity of the seal affect circuit reliability? What is the significance of the measured integrity of the seal? What is the relationship of Residual Gas Analysis and the seal integrity? The handbook answers these questions and more, providing an analysis of nearly 100 problems representative of the wide variety of challenges that actually occur in industry today.


Packaging engineers, scientists and technicians as well as novice users, package designers, reliability engineers and those who measure and evaluate the integrity of packages, especially in the field of microelectronics.

Table of Contents


Preface to the First Edition

Preface to the Second Edition

About the Authors


1. Gas Kinetics

1.1. General Considerations

1.2. Mathematical Relationships

1.3. Problems and Their Solutions

2. Viscous and Molecular Conductance of Gases

2.1. Conduction of Gases

2.2. Viscous Conduction

2.3. Molecular Conduction

2.4. Conduction in the Transitional Range

2.5. Composite Conductance Equations

2.6. Smallest Theoretical Leak

2.7. Discussion

2.8. Problems and their Solutions

3. The Flow of Gases

3.1. General Flow Characteristics

3.2. Measured, Standard, and True Leak Rates

3.3. Leak Rates for Different Gases

3.4. Change of Partial Pressure With Time

3.5. Viscous Flow From Sealed Packages

3.6. Viscous Flow Rates of Different Gases

3.7. Problems and Their Solutions

4. The Flow of Gases into Sealed Packages

4.1. Molecular Flow

4.2. Oxygen Leaking Into Sealed Packages

4.3. Viscous Flow Into and Out of Sealed Packages

4.4. The Simultaneous Flow of Gases in Both Directions

4.5. Problems and their Solutions

5. Understanding Fine Leak Testing in Accordance with Method 1014, MIL-STD-883

5.1. Purpose of the Test

5.2. Basis of the Test

5.3. Fixed Method of Testing

5.4. Flexible Method of Testing

5.5. Comparison of the Fixed and Flexible Methods

5.6. The Effect of Viscous Flow

5.7. Leak Rate Limits are Too Lenient

5.8. Backfilling the Package with Helium

5.9. Bombing after Backfilling

5.10. Leak Rate Measurements Using Krypton-85 Tacer Gas

5.11. Problems and their Solutions

6. Fine Leak Measurements Using a Helium Leak Detector

6.1. Principle of Operation

6.2. Definitions<


No. of pages:
© 2011
William Andrew
Electronic ISBN:
Print ISBN:
Print ISBN: