Episode 156: An Introduction to Flexible Circuits with Joseph Fjelstad

On today’s episode, we’re turning our focus to a pivotal innovation that has transformed design and manufacturing processes: flexible circuits.Flexible circuits have emerged as a game-changer in the manufacturing and design of electronic assemblies. With their unique ability to bend, twist, and conform to complex shapes, they offer unparalleled advantages in applications where space is at a premium and reliability is paramount. From wearable technology and medical devices to aerospace systems and consumer electronics, the use of flexible circuits has expanded rapidly, bringing with it both opportunities and challenges.In this episode, we’ll explore the evolution of flexible circuit technology, discussing its key benefits, such as lightweight construction, enhanced durability, and improved design freedom. We’ll also touch on the manufacturing complexities, material considerations, and the critical role that process control plays in ensuring reliability and performance.My guest today is Joseph Fjelstad. Joe is the founder of Verdant Electronics. Joseph Fjelstad has been active in electronics manufacturing since 1972 in various roles, including as a chemist, process engineer, and R&D manager. He holds nearly 190 U.S. Patents and numerous foreign ones. He is an internationally recognized expert, inventor and lecturer in the field of electronics interconnection technology and a veteran of several startup companies, including: Beta Phase, ELF Technologies, MetaRAM, Silicon Pipe, and Tessera (now the public company, Xperi).Some of Joe’s innovative devices and novel reliability improving IC packaging structural features are found in nearly every electronic device made today. He is also an author, co-author or editor of several books on interconnection technology, including Flexible Circuit Technology 4th Edition, the most widely distributed reference book on the topic, Chip Scale Packaging for Modern Electronics, and Solderless Assembly For Electronics — The SAFE Approach. In addition, Fjelstad has written hundreds of articles, columns and commentaries for various industry magazines and journals over the last five decades. And today, he’s the guest on my show.Here is a list of Joe's books:Flexible Circuit Technology 4th Editionhttps://iconnect007.com/my-i-connect007/books/flex-circuit-technologyChip Scale Packaging for Modern Electronicshttps://www.emerald.com/insight/content/doi/10.1108/cw.2004.21730bae.001/full/htmlSolderless Assembly for Electronics: The SAFE Approachhttps://iconnect007.com/my-i-connect007/books/solderless-assembly-electronics-safe-approach#:~:text=SAFE%20technology%20(Solderless%20Assembly%20For,design%20efficacy%2C%20reliability%20and%20security.Joe's Company:Verdant Electronicshttps://verdantelectronics.net Chapters:00:00:00 Importance of Flexible Circuits in Modern Electronics  00:02:42 Exploring the World of Flexible Circuits  00:05:30 Introduction to Flexible Circuits: A Historical Perspective00:08:43 Entrepreneurship Mindset: Naivety and Innovation00:11:08 The Value of Naivety in Engineering  00:13:43 Innovations in Bubble Printing Technology  00:16:47 Understanding Flex Circuits: Applications and Challenges00:19:58 The Lifespan and Failure of Torsion Bars  00:22:21 Evolution of Soldier Technology: From Heads-Up Displays to Wearables00:25:24 The Origins of the Integrated Circuit00:28:13 Advances in Microelectronics: From Printed Transistors to Modern Tech00:31:28 Challenges and Solutions in Flexible Circuit Design00:34:00 Collaborative Design for Efficient Manufacturing  00:36:49 Advances in Flexible HDI and the Upcoming Ultra HDI Conference  00:39:46 Evolution of Flexible Circuits: From 1903 to Present   00:42:40...