September 8-10, 2003
Omni Shoreham Hotel
Washington, D. C.
U. S. A.

49th IEEE Holm Conference on Electrical Contact

 

This year's technical program will fill the two and half day conference with the following highlights:

1

34 reviewed technical papers - see paper abstracts

2

Ragnar Holm Scientific Achievement Award presentation -  Dr. Robert Malucci, "Fretting Corrosion Degradation, Threshold Behavior and Contact Instability"

3

Dr. Morton Antler Invited Lecture - Mr. Norm Traub of the Society of Automotive Engineeers, "Challenges and progress of the 42V power net in future automobiles"

4

Workshop on the transition to a lead-free industry - Wayne Johnson (Auburn University), Pete Elmgren (Molex), Robert Hilty (Tyco Electronics), Neil Brown (Shipley), Jonathan Best (Delphi Packard Electric Systems)

 

I.  Ragnar Holm Scientific Achievement Award Presentation -
Dr. Robert Malucci, "Fretting Corrosion Degradation, Threshold Behavior and Contact Instability"

Abstract - During the last three decades many authors have conducted empirical studies on the impact fretting corrosion has on base metal contacts.  Generally the goals of these studies were to evaluate the performance of various material systems such as tin and tin alloy contacts.  In some cases, contact stability and thermal effects were studied to shed light on the performance of various contact configurations in specific applications. Consequently, a body of data has accumulated in the literature covering various aspects of this degradation mechanism.  Most of these studies were conducted by artificially causing micro-motions at a contact interface using various laboratory fixtures. Moreover, most of these studies were not aimed at evaluating fundamental fretting parameters but rather to reveal the performance of specific material systems.

Over the past several years, in an effort to shed light on connector performance and develop meaningful accelerated tests, the present author has pursued a number of efforts to understand the fundamentals of fretting corrosion and how they relate to real world field conditions. Moreover, the impact of fretting degradation on contact stability was studied to understand how this mechanism might impact electronic systems.  These studies were intended to extend the present data base and our understanding of fretting corrosion as a serious degradation mechanism in the field.  To this end, the present author has investigated the effects of fretting amplitude, contact force, temperature and vibration to model fretting behavior and subsequently provide a basis for understanding this mechanism. This work was done using two separate approaches. The first employed controlled laboratory experiments where artificially induced fretting was used to investigate basic fretting parameters. The second used various environmental tests on actual connector products to evaluate acceleration factors. The initial goals were to study the effects of these variables and the nature of the oxide films as they accumulate in the contact region. Subsequently, an empirical model was developed to aid in designing accelerated laboratory tests that utilize thermal cycling and vibration as major stress factors. During the course of these studies, a number of characteristics such as oxide film build up and electrical stability were revealed as fretting progressed. Moreover, threshold behavior was observed with respect to fretting amplitude, which is believed related to field stresses. Factors such as vibration g-levels and temperature-swings, which characterize field stresses, were subsequently used to interpret laboratory tests. 

 This paper addresses the electrical behavior of contacts as fretting corrosion progresses. To this end, the results developed over the last several years are summarized and used to provide an understanding of fretting corrosion phenomena and accelerated testing. The oxide build up and associated impact on film characteristics and contact stability are considered.  In addition, the nature of the fretting degradation process is analyzed in the context of chaotic processes.  Analyses of phase space parameters and non-linear dynamic behavior are conducted to reveal chaotic behavior as contact degradation progresses towards higher and unstable resistance. The overall objective is to reveal the nature of the degradation mechanism and provide a basis for understanding how test parameters and failure criteria relate to threshold behavior and contact stability.  

 

II.  Dr. Morton Antler Invited Lecture -
Mr. Norm Traub of the Society of Automotive Engineeers, "Challenges and progress of the 42V power net in future automobiles"

Norman L. Traub was named Director of 42 Volt Initiatives for SAE International on February 1, 2001. He was subsequently named Director of Electrical Initiatives in February, 2003. 
Traub has lectured extensively on 42V electrical systems, including the SAE World Congress, International Power Electronics Conference, International Society of Automotive Transportation and Technology, IEEE Workshop on Power Electronics in Transportation and two international congresses on 42-V PowerNet. He was the moderator for 42-V Executive Panel sessions held during SAE World Congresses in 2001, 2002 and 2003. Global journalists from England, France, Germany and the USA also have interviewed Traub for his technical expertise and insight.
Currently, Traub holds the position of chairman of the 42-V Battery Connection System Specification Workgroup, a multi-national standards workgroup of vehicle manufacturers, battery suppliers and connection companies. He is a  member of the MIT/Industry Consortium on Advanced Automotive Electrical/Electronic Components and Systems (50 multi-national companies). He is also the chairman of the SAE 42V Advisory Committee. 
Traub began his career at the General Motors Research Laboratories in 1967 as a senior engineer in the electrical engineering department, where he became the holder of four U.S. patents and numerous research reports/publications in the areas of automotive multiplexing, large industrial drive systems, electric cars and automotive safety/security systems. 
In 1978, Traub transferred to the former Packard Electric Division of GM in Warren, Ohio. His promotion to senior staff engineer in 1990 resulted in his assignment as head of the Systems Development Center. In 1996, Traub was appointed technology integration manager at Delphi Automotive Systems, Packard Electric Division.

Traub received his bachelor’s degree in electrical engineering from Valparaiso University and his master’s degree in electrical engineering from Michigan State University.


III.  Workshop on the transition to a lead-free industry

  • Overview: Legislative pressure to remove lead-containing materials from electronic products is rapidly increasing.   The pending impact on the contact and connector community has prompted a great deal of research activity, including many screening evaluations of lead-free solders, lead-free plating finishes, and lead-free compatible manufacturing / processing strategies.   This workshop is intended to help the attendee develop a better understanding of the relevant issues through a review that will include:  
    ·        background on the principal legislative initiatives
    ·        reliability of lead-free solders
    ·        reliability of lead-free solderable, contact, and press-fit plated interfaces
    ·        plating chemistries / processes utilized for depositing lead-free finishes
    ·        potential impact of lead-free finishes on the metal stamping process
    ·        inevitable concerns about the formation of metallic whiskers from pure tin. 
  • Legislative pressureThe workshop will commence with a series of short presentations by each panel member on the subjects mentioned above, and then the session will be opened up for a moderated, panel-like discussion driven by questions from the audience.

 Workshop Panel Abstracts: 

  • Wayne Johnson (Auburn University) - The elimination of Pb in electronics assembly has been discussed since 1990.   Increasing restrictions on hazardous materials in landfills, recycling requirements, and manufacturer responsibility for products from ‘cradle-to-grave’ have kept the topic of Pb in the mind of manufacturers. Today, with proposed legislation in Europe and global competitive market pressures, particularly in Japan, the elimination of Pb in many, if not all, electronic products appears imminent. This presentation will examine the current state of legislative activity with particular focus on the WEEE Directive in Europe.  This will be followed by a discussion of reliability issues such as tin whiskers and thermal cycle reliability associated with the switch to lead free electronics assembly.
  •  Pete Elmgren (Molex) - Tin-lead coatings, the primary source of lead in the connector industry, have been used for decades to provide a low cost, solderable, corrosion resistant, and reliable electrical interconnect.  As lead is eliminated from the plating finish of future products, these properties must be maintained through the proper selection of lead-free plating.  Of the potential candidates to replace tin-lead, including pure tin, tin-copper, tin-bismuth, tin-silver and certain precious metals, the one that comes closest to property, performance, and cost parity is pure tin.  Tin shows good wetting characteristics during soldering, which helps create a reliable solder joint.  Tin also has a proven history of stable performance as a separable contact interface material.  However, pure tin plating finishes have received significant scrutiny of late because of the fear that they may grow tin whiskers.  Numerous studies have attempted to identify accelerated tests for longer-term validation of the absence of whiskers without success.
  •  Robert Hilty (Tyco Electronics) - Press-fit interconnects have received relatively little attention in the world of lead elimination.  RoHS exemptions for solder in server applications do not apply to press-fit interconnects, thus lead-free versions will be required.  PCB suppliers are capable of producing many lead free finishes; similarly, component suppliers have several lead free options available.  This work will briefly review the issues involved when lead is removed from the press-fit interconnect system.   We will also summarize the performance variations that occur with new lead-free materials.
  •  Neil Brown (Shipley) -  Pure tin electrodeposits have been identified as possible Pb-free surface finishes to replace conventional tin-lead coatings.  Although pure tin has advantages with respect to process control and simplicity of operation, the possibility of tin whisker growth has limited its widespread implementation and acceptance.  Various theories on the causes of tin whisker growth, including the influence of substrates and deposit characteristics, will be reviewed.  Whisker test methods and results will also be shown to demonstrate the effect of processing parameters on whisker growth and correlation to some of the proposed theories.
  •  Jonathan Best (Delphi Packard Electric Systems) -  The various replacement options for tin lead plating each have different characteristics that may impact the stamping processes used to produce terminals.  The presentation will provide an overview of the stamping process.  The basic types of metal forming operations involved in producing terminals will be covered, including how the plating is affected by or can affect these operations.

Biography - Panel Members

  •  Wayne Johnson - Ginn Professor of Electrical Engineering, Auburn University 
    Dr. Johnson is a Ginn Professor of Electrical Engineering at Auburn University and Director of the Information Technology Peak of Excellence. At Auburn, he has established teaching and research laboratories for advanced packaging and electronics assembly.   Research efforts are focused on materials, processing, and modeling for electronics assembly with a special emphasis on harsh environment applications.
    Dr. Johnson is currently the Vice President for Technology for the International Microelectronics and Packaging Society (IMAPS). He was the 1991 President of IMAPS. He received the 1993 John A. Wagnon, Jr. Technical Achievement Award from IMAPS, was named a Fellow of the Society in 1994 and received the Daniel C. Hughes Memorial Award in 1997. He is also a member of IEEE, SMTA, and IPC.
    Dr. Johnson received the B.E. and M.Sc. degrees in 1979 and 1982 from Vanderbilt University, Nashville, TN, and the Ph.D. degree in 1987 from Auburn University, Auburn, AL, all in electrical engineering. He has worked in the microelectronics industry for DuPont, Eaton, and Amperex.
  • Pete Elmgren - Manager of Advanced Development, Molex
    Pete Elmgren manages Molex’s Advanced Development group, which is responsible for corporate leadership on issues of interconnect materials, materials processing, and electrical engineering.  Additionally, he is presently responsible for the development and implementation of Molex’s lead-free solutions.  He has developed over 20 years of experience in the microelectronics industry through a variety of positions within IBM, Digital Equipment Corporation, and Molex.  He is a graduate of Lafayette College where he received the bachelors degree in Metallurgical Engineering.
  •  Robert Hilty - Manager of Materials Research, Tyco Electronics
     Dr. Hilty manages a group of scientists and engineers performing research and development in the fields of materials and contact physics.  In this capacity he also serves as the technical lead for Pb free development and implementation.  His experiences at AMP Incorporated, then Tyco Electronics have included materials research, product development, and failure analysis.  He has been employed by Tyco Electronics/AMP for 10 years.
    Dr. Hilty is a graduate of Rensselaer Polytechnic Institute, where he earned his Ph.D. in Materials Engineering and Science.  He is also a graduate of Temple University, where he earned a bachelors degree in mechanical engineering.   He is a registered professional engineer in Pennsylvania.
  •  Neil Brown - Research and Development Manager, Shipley
     Neil Brown is Research Manager at Shipley Company in Freeport, NY, responsible for development of processes for connector, semiconductor packaging, and industrial finishing applications.  He received his B.S. degree in Chemical Engineering from Rensselaer Polytechnic Institute.  During his 18 years at Shipley he has held various positions in the R&D group and holds a number of patents on tin and tin-lead plating chemistries.
  •  Jonathan Best - Metallurgist, Delphi Packard Electric Systems
     Jonathan Best joined Delphi Packard Electric Systems in 2000 as a metallurgist after earning his bachelors and masters degrees in Materials Science and Engineering from Case Western Reserve University.  In his present position, he is responsible for providing technical support to both product design and manufacturing engineering with respect to raw material supply and specification.  With the coming transition to lead-free, he will be coordinating Delphi Packard Electric Systems’ identification, testing, and specification of lead-free materials.

 

 6/16/2003