P. Bojta

Searching for appropriate humidity accelerated migration reliability tests methods

Abstract Lifetime estimation is one of todays frequently used reliability testing tool. There are standardized test methods, mathematical apparatus and failure acceleration models for predicting failure rate of electronic components, circuit modules or equipment. Do the widespread used models give a precise description for all kind of failure mechanisms? Can they define the acceleration factor of any test, and the accelerated lifetime of any test vehicles? In connection with open surface migration tests (when the test circuit samples are not covered by any protective or packaging material) two climatic test methods (Thermal Humidity Bias––THB test methods with different parameter settings) have been compared: 40 °C/95%RH suggested by “a well known IEC standard” and 85 °C/85%RH required by the newer JEDEC standard. The novelty of the paper is the comparison between the two climatic test methods. The main conclusion is a suggestion to keep on with the old method in the mentioned particular case, which may be shocking for people who prefer the new standards. All conclusions are strengthened both with theoretical and experimental test results.

Progress in electronics packaging virtual laboratory development

The development of information technology has opened new perspectives in electronics packaging education to prepare engineers for the needs of the 21/sup st/ century. The Department of Electronics Technology has been working on the improvement of the education in this respect for many years. It has obtained an IEEE/NSF grant in 1999 to create the Virtual Laboratory, a solution of the educational support with the newest and high-quality Web-technology. This paper gives a summary of the results of the one-year long practical development.

SensEdu-an Internet course for teaching sensorics

Conventional teaching of sensors, based on lectures, static written materials, laboratories, etc., has become rather difficult at all levels of education, recently. The main objective of the described project is the development of a multimedia supported education material that teaches the application of microelectronics and packaging technologies in designing smart sensor devices for the next generation intelligent systems. The new approach of teaching sensorics tries to exploit all advantages of multimedia computer aided teaching not only for keeping the competitiveness but also in order to overcome the above specific difficulties of the particular area. The course material will be available for the technical community, for other university professors for teaching, and also will continuously be developed on the Internet and on CDs. The paper will highlight the structure of the course material and demonstrate the animated sensor examples.

MEMSEdu: a project for developing an Internet course for teaching basic MEMS technologies and applications

MEMS (micro-electro-mechanical systems) including also MOEMS (micro-opto-electro-mechanical systems) represent a progressive area of electrical/mechanical engineering. To supply this field with well-educated engineers, it is necessary to teach them basic sciences, technology, applications, and design aspects (reliability, packaging, etc.) belonging to the topic of M(O)EMS. Conventional teaching methods, based on lectures, static written materials, laboratories, etc., has become rather difficult at all levels of education. The main objective of the described project is the development of a multimedia supported education material that teaches the theoretical background, application of microelectronics, and packaging technologies in designing micro-electromechanical systems for the next generation of intelligent systems. The new approach tries to exploit all advantages of multimedia computer aided teaching not only for keeping the competitiveness but also in order to overcome the specific difficulties of the particular area. The modern educational software tool can secure up to date information, easy-to-understand visualisation of the 3D MEMS structures and interactive examples of the subject. The course material will be available on the Internet and on CDs for the technical community, for other university professors for teaching, and also will continuously be developed. The paper highlights the structure of the course material and demonstrates animated examples.

Failure and acceleration models for MCM-Ls tested by HAST

In the course of the last few years, new component package types and high density interconnect (HDI) substrate technologies have emerged and presented new challenges to manufacturers. New package types include a great variety from flip chips (FCs), through quad flat packs (QFPs), to micro ball grid arrays (micro-BGAs) and chip scale packages (CSPs), while for substrates, laminated or build-up HDI technologies are preferred. In particular, laser via generation and patterning technology provided new possibilities in the field of the fabrication of laminate substrates for multichip modules (MCM-Ls). Since the application of a new technology always brings new degradation and failure mechanisms, reliability testing and failure analysis are necessary to maintain the quality of products and parts.

SensEdu - an Internet course for teaching sensorics

Conventional teaching of sensors, based on lectures, static written materials, laboratories, etc., has become rather difficult recently, at all levels of education. The main objective of the described project is the development of a multimedia supported education material that teaches the application of microelectronics and packaging technologies in designing smart sensor devices for the next generation intelligent systems. The new approach of teaching sensorics tries to exploit all advantages of multimedia computer aided teaching not only for keeping the competitiveness but also in order to overcome the specific difficulties of the particular area. The course material will be available for the technical community, for other university professors for teaching, and also will continuously be developed on the Internet and on CDs. The paper will highlight the structure of the course material and demonstrate the animated sensor examples.

An Internet course for teaching basic MEMS technologies and applications: MEMSEdu

Conventional teaching methods, based on lectures, static written materials, laboratories, etc., have become rather difficult at all levels of MST (microsystems technologies) education, recently. To supply this field with well-educated engineers with interdisciplinary knowledge, it is necessary to teach them basic sciences, technology, applications, and designing aspects (reliability, packaging, etc.) belonging to the topic of MST. Also the knowledge of user engineers should be upgraded-possibly in a form of distance learning. The main objective of the described project here is the development of a multimedia supported education material that teaches/overviews the theoretical background, manufacturing, as well as practical application of microelectronics, microelectro/opto/mechanical systems and their packaging technologies in order to prepare experts for designing next generation intelligent micro/nanointegrated systems in the new century. The new approach tries to exploit all advantages of multimedia computer aided teaching not only for keeping the competitiveness but also in order to overcome the specific difficulties of the particular area. The modern educational software tool can secure up to date information, easy-to-understand visualisation of the 3D MEMS structures and interactive examples of the subject. The course material will be available both on the Internet and on CDs for the technical community, for other university professors for teaching, and also will continuously be developed.

Multimedia for MEMS technologies and packaging education

MSTs (Micro-Systems Technologies) including ow subject MEMS (Micro-Electro-Mechanical Systems) represent a progressive area of electricall mechanicalhiomedical engineering. They allow the manufacture of miniature (micrometer level) electromechanical devices. These devices can both replace conventional devices and sub-systems at a fraction of their cost, with enhanced reliability and durability and, frequently open up entirely new applications where the sue and cost of devices based on conventional technology has prevented their use. Microsystems technology is a potentially disruptive technology. It is set to have enormous impact across the industrial spechum. Already the technology is sufficiently mature for MST based components and sub-systems to be available for incorporation into a wide range of existing equipment and systems. Its take up is set to take-off dramatically over the next five years, with substantial impact on the performance and competitiveness of many “every day” products and systems for industrial and consumer market. To supply this field with well-educated engineers with interdisciplinary knowledge, it is necessruy to teach them hasic sciences, technology, applications, and designing aspects (reliability, packaging, etc.) belonging to the topic of MSTs. Also the knowledge of user engineers should be upgraded-possibly in a form of distance learning. Conventional teaching methods, based on lectures, static written materials, laboratories, etc., has become rather difficult at all levels of MST education, recently. The main objective of the described project here is the development of a multimedia supported education material that teachesioverviews the theoretical background, manufacturing, as well as practical application of microelectronics, microelectro/opto/mechanical systems and their packaging technologies in order to prepare experts for designing next generation intelligent micro/nanointegrated systems in the new century. The new approach tries to exploit all advantages of multimedia computer aided teachmg not only for keeping the competitiveness but also in order to overcome the specific difficulties of the particular area. The modem educational software tool can secure up to date information, easy-tounderstand visualisation of the 3D MEMS structures and interactive examples of the subject. The course material will be available both on the internet and on CDs for the technical community, for other university professors for teaching, and also will continuously be developed. The paper will highlight the structure of the course material and demonstrate the animated examples.

A multimedia course for the design of microsystem packages

Teaching the design of microsystem packages is one of the most important topics in the BSc and MSc level university education of electronic engineering. Special emphasis should be laid on teaching design, according to the general opinion that industrial companies are suffering from a shortage of design engineering staff. In addition to providing courses on CAD design in regular university curricula, courses and training should be developed and provided for industrial engineers. The aim of such courses is to bridge the gap between the knowledge that is provided by the different undergraduate modules and that which is necessary and relevant for the industrial labor market and/or requested by the graduate educational modules for further qualification. Internet accessible, interactive, multimedia equipped, distant learning virtual laboratory experiments have to be offered for exploratory training to improve the knowledge of industrial engineers. The present paper reviews a part of a course that tries to meet these requirements.

Modeling moisture caused failures in stress tests

The most important time related parameter of electronic systems is MTTF (mean time to failure). In accelerated aging tests, the circuits are exposed to enormously harsh environmental conditions. The accelerating parameters and events like mechanical vibration and shock, temperature, pressure, humidity and their combinations are used as loads in stress test methods. There are different models to describe the effects caused by the mentioned stresses. In most cases, these models only include some of the parameters, but none describe all the possible effects of a stress test. By obtaining more information about the materials used in the test vehicle and integrating the available models, it is possible to derive a mostly complete model of moisture permeation, including ad-/absorption and diffusion effects. This paper gives an overview of the available models and shows a first-enclosing simulation of moisture penetration.