Reliability of Microtechnology

Transcription

1 Reliability of Microtechnology

2

3 Johan Liu Olli Salmela Jussi Särkkä l l James E. Morris Per-Erik Tegehall l Cristina Andersson Reliability of Microtechnology Interconnects, Devices and Systems

4 Johan Liu SMIT Center and Bionano Systems Laboratory Department of Microtechnology and Nanoscience Chalmers University of Technology Kemivägen 9, SE Göteborg Sweden and Key Laboratory of New Displays and System Integration SMIT Center and School of Mechatronics and Mechanical Engineering Box 282, Room 316, Mechatronics Building, Shanghai University No 149, Yan Chang Road Shanghai , China Olli Salmela Nokia Siemens Networks Linnoitustie 6, FI Espoo Finland James E. Morris Department of Electrical & Computer Engineering Portland State University P.O. Box 751, Portland OR USA Per-Erik Tegehall Swerea IVF Box 104, SE Mölndal Sweden Cristina Andersson Department of Microtechnology and Nanoscience Chalmers University of Technology Kemivägen 9, SE Göteborg Sweden Jussi Särkkä Nokia Siemens Networks Kaapelitie 4, FI Oulu Finland ISBN e-isbn DOI / Springer New York Dordrecht Heidelberg London Library of Congress Control Number: # Springer Science+Business Media, LLC 2011 All rights reserved. This work may not be translated or copied in whole or in part without the written permission of the publisher (Springer Science+Business Media, LLC, 233 Spring Street, New York, NY 10013, USA), except for brief excerpts in connection with reviews or scholarly analysis. Use in connection with any form of information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed is forbidden. The use in this publication of trade names, trademarks, service marks, and similar terms, even if they are not identified as such, is not to be taken as an expression of opinion as to whether or not they are subject to proprietary rights. Printed on acid-free paper Springer is part of Springer ScienceþBusiness Media (

5 Foreword As a society, our dependency on electronics products permeates every corner of the world, at an ever accelerated pace. As an industry, we have been and will continue to place the highest priority on product reliability, while facing increasingly demanding customers and mounting competitive pressures. It is widely recognized that product reliability issues can result in inconvenience in some cases and catastrophe in others. It is, therefore, a matter of the utmost importance that we educate our college students and practicing engineers on the reliability of microtechnology its theory and practical applications. The issue of reliability, however, is complicated by the wide variety of application environments and requirements, which give rise to different stress conditions (thermomechanical, dynamical, electrochemical, electrical, etc.). The picture is further complicated by the constant emergence of new applications (therefore the associated use and environmental conditions), new product designs, new materials, and new processes. We are fortunate to have a few dedicated experts who can lead and guide us through the critical but complex issues associated with electronics reliability. We have learned a great deal from them at conferences and workshops; however, a comprehensive text book has long been awaited. This book is very timely indeed. September, 2010 Dongkai Shangguan, Ph.D., MBA Vice President Flextronics Visiting Professor HUST, China Fellow IEEE v

6

7 Preface This book serves as a teaching material concerning reliability of microtechnology and covers topics from devices to systems in the final year of undergraduate and first year of graduate education including questions and answers for self-study. The book is also useful for reliability engineers for reliability assessment, modeling, and quality control purposes. The book includes reliability issues of interconnects, component up to system level. The methodology of reliability concept is addressed in the first chapters and followed by general failure mechanisms including specific failure modes in solder and conductive adhesives. Accelerated testing, interconnect, component, and system-level reliability are described also in detail as well as the reliability design for manufacturability. Finally, quality and reliability management issues as well as characterization tools for reliability are described. Gothenburg September, 2010 Johan Liu Member of the Royal Swedish Academy of Engineering Sciences (IVA) Fellow IEEE Professor Chalmers University of Technology, Sweden Special Recruited Professor Shanghai University, China vii

8

9 Contents 1 Introduction to Reliability and Its Importance Introduction... 1 References Reliability Metrology The Definition of Reliability Empirical Models Physical Models Reliability Information Interconnection Reliability The Levels of Interconnections Reliability Function Exponential Distribution Weibull Distribution Log-Normal Distribution Physical Basis of the Distributions A Generic Weibull Distribution Model to Predict Reliability of Microsystems Failure-Criteria Dependence of the Location Parameter Least Squares Estimation The Experiment and Data Analysis and the Results Application of the Results Exercises References ix

10 x Contents 3 General Failure Mechanisms of Microsystems Introduction Mechanical and Thermomechanical Failure Mechanisms Low Cycle Fatigue Creep Brittle Fracture IC Level Failure Mechanisms Electromigration Electrostatic Discharge Corrosion Plastic Package Popcorning Exercises References Solder Joint Reliability Microstructure of Solder Joints Microstructure of Eutectic Sn 37Pb Microstructural Stability and Interfacial Interactions Microstructure of Eutectic Sn 3.5Ag Microstructural Evolution and Interfacial Interactions Microstructure of Sn Ag Cu Alloys Microstructural Evolution and Interfacial Interactions Microstructure of Sn 3.5Ag 3Bi Microstructure of Sn 0.7Cu 0.4Co Mechanical Reliability of Solder Joints Fatigue Failure General Solder Joint Failure Mechanism Effect of Second Level Solder Interconnection Failure Standards Related to Solder Joint Reliability Testing Exercises References Conductive Adhesive Joint Reliability Introduction to Conductive Adhesives Isotropic Conductive Adhesive Reliability of ICA Interconnects Effect of Metallization Effect of Curing Degree Impact Strength Failure Mechanisms Electron Conduction Through Nanoparticles in ICA Reliability of ACA Interconnects Effects of Assembly Process Effects of Substrate and Component... 85

11 Contents xi Degradation Due to Moisture Absorption Oxidation and Crack Growth Probabilities of Open and Bridging ACA Flow During Bonding Electrical Conduction Development and Residual Stresses Exercises References Accelerated Testing Fatigue Failure Analysis for Accelerated Testing Thermal Fatigue Effect of Different Test Factors on Thermal Fatigue Life Isothermal Mechanical LCF Effect of Frequency Effect of Dwell (Hold) Time Effect of Strain Range and Strain Rate Effect of Temperature Effect of Failure Definition Effect of Other Factors Exercises References Reliability Design for Manufacturability Lead-Free Soldering Higher Process Temperature Other Issues Lead Contamination Tin Whiskers Inspection Repair and Rework Exercises References Component Reliability Introduction Empirical Models The Methodology Empirical Models in System Reliability Analysis Limitations of Empirical Models and Recommendations on Use Exercises References

12 xii Contents 9 System Level Reliability Introduction Some Constant Hazard Rate Approximations of the Weibull Distribution Resulting Functions and Hazard Rates Properties of Different Options Comparison of the Selected Options Selection of Time Intervals The Motivation for Selecting Two-Parameter Weibull Distribution Constant Failure Rate and Its Origin in the Field Failure Data Exercises References Reliability and Quality Management of Microsystem Introduction Activity 1: Product Requirements and Constraints Activity 2: Product Life-Cycle Conditions Activity 3: Selection and Characterization of Alternative Product Architectures and Manufacturing Processes Activity 4: Qualification of Packaging Concepts and Manufacturing Processes Manufacturability Reliability Maintainability Environmental Compatibility Activity 5: Risk Management and Balance of Functionality, Quality, and Cost Requirements Risk Management of Supplied Materials and Parts Risk Management of Manufacturing Processes and New Technologies Failure Modes and Effects Analysis Protective Measures Activity 6: Quality Controls and Improvement of Design, Materials, Parts, and Manufacturing Processes Design Defects Defects Caused by Manufacturing Processes Activity 7: Failure Analysis and Feedback of Gained Knowledge Exercises References

13 Contents xiii 11 Experimental Tools for Reliability Analysis Optical Microscopy Scanning Electron Microscopy Energy-Dispersive X-Ray Scanning Acoustic Microscopy X-Ray Low-Cycle Fatigue Testing Shear Testing Humidity and Temperature Testing Thermal Shock and Thermal Cycling Testing Moiré Interferometry Exercises References Abbreviations Answers to the Exercises Index

14