RM 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. Mike Konrad's 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 US 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. 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 Perspective 00:08:43 Entrepreneurship Mindset: Naivety and Innovation 00:11:08 The Value of Naivety in Engineering   00:13:43 Innovations in Bubble Printing Technology   00:16:47 Understanding Flex Circuits: Applications and Challenges 00:19:58 The Lifespan and Failure of Torsion Bars   00:22:21 Evolution of Soldier Technology: From Heads-Up Displays to Wearables 00:25:24 The Origins of the Integrated Circuit 00:28:13 Advances in Microelectronics: From Printed Transistors to Modern Tech 00:31:28 Challenges and Solutions in Flexible Circuit Design 00:34:00 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 Innovating Flexible Circuits   00:45:13 Evolution of Toll Road Technology 00:48:08 The Future of Flexible and Stretchable Circuits 00:51:53 Introduction to Verdant Electronics   00:54:46 The Military's Stance on Lead-Free Technology   00:56:27 Innovating Solderless Technology 00:59:18 Insights on Persistence and Success in Entrepreneurship