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Flexible Thinking: The Adjacent Possible

In the inspirational and informative book titled Where Good Ideas Come From, author Steven Johnson uses the term "the adjacent possible." This term, which immediately captivated my mind, originated with a theoretical biologist named Stuart Kaufman, who used the term in his book, Investigations, to describe the circuitous path of biological evolution. For Johnson, however, the “adjacent possible,” which is one of the places “good ideas come from,” conceptually includes everything that’s one step away from what currently exists, with more is yet to come. This is important. There is a necessary precondition that there must be an immediate nexus to make something “adjacently possible.”

This notion made immediate sense to me as an unrepentant futurist and inventor. I suspect it is a term that might or should resonate with other inventors as well. One might be able to sense something special waiting to be discovered in the future, but one must first secure their intellectual foothold in the present time and place to successfully take the next step. One must conquer what is near before they can approach and conquer what’s in the distance. Interestingly, once one secures what is adjacent, new adjacencies appear that might cause a beneficial change in thought or direction. In this way, invention is a constant and never-ending process in much the same way that Kaufman envisioned the path of biological evolution in his thesis.

To that end, and with regard to the evolution of the electronics industry, I had an epiphany a few months ago: I realized I had purchased my first integrated circuit around 1957 using three months of savings from my paper route. That purchase occurred a full year ahead of Jack Kilby’s demonstration of the first integrated circuit which had been cobbled together from a piece of germanium connected to a few resistors and capacitors using gold wires. The integration of transistors for my “integrated circuit” was a very simple printed circuit with six transistors soldered to it. Granted it was a rather large “integrated circuit,” but it definitely integrated those transistors and other components and made them work together, allowing me to listen to amplified music from radio stations that were in working proximity.

I cannot say for certain if Kilby had a printed circuit in mind when he built his demonstration, but I know that he worked at CentraLab in Milwaukee, which made ceramic printed circuits for military and commercial customers. Thus, it seems not to be a great stretch of imagination that Kilby saw and took advantage of “the adjacent possible” to create his world-changing invention.

Around the same time—and independently from Kilby—Robert Noyce, then at Fairchild, invented a process for producing defined areas of conductors and insulators on a semiconducting base material, a process that has been continually refined using the concept of “the adjacent possible” ever since, and in the pursuit of extending the life of Moore’s law.

Printed circuits also followed the path of the adjacent possible from single metal layer circuits to double-sided boards to multilayer circuits to flex and rigid-flex. So has been the path for assembly from through-hole to surface mount, from one-side assembly to two-side assembly. From the late 1990s to today, the effort has been focused on making circuit features an ever-smaller transition from high-density interconnections (HDI) to ultra high-density interconnections (UHDI) with feature sizes that are smaller than those used on first-generation integrated circuits.

About 15 years ago, the Occam Process was proposed, but it was not considered a step toward the adjacent possible, However, it seems clear that it fits the description. The concept as written up can, by taking a step toward the adjacent possible, potentially addresses and solves at one time a number of problems that have long faced the industry. Most of them are related to solder and the problems inherent in the soldering process, especially those related to high temperature damage to circuit board features, such as plated through-holes and electronic components, not to mention the myriad assembly challenges faced daily by manufacturing engineers.

When viewed in the light of the work of Jack Kilby, the Occam Process, which preaches minimalism in design (“It is vanity to do with more that which can be done with less”—William of Occam), proposes to do something that can be done immediately by simply reversing the process of assembly. That is, rather than building a printed circuit and soldering components to it, build a “component board” and build the circuits required for interconnection for those components on one or both sides of it using processes that are being developed to make HDI and UHDI boards.

These components will ideally have all the same I/O pitch to make board layout easier, as I described several years ago when I suggested in a paper to “dis-integrate” ICs into their constituent IP blocks. Such structures are presently being called “chiplets.” It is a step in the right direction but what is largely ignored is the need for packages to provide a common pitch and standards for I/O locations providing compatibility between vendors. These ideas have, arguably, always resided in the realm of the adjacent possible and what is next becomes adjacently possible. When the leap is made, the possible begins to expand exponentially, much the way that life has done since it first appeared on this fortunate blue marble in space.

I am inclined to believe that the adjacent possible I see will be embraced in the future, not because time has proven me right many times in the past but because its time is drawing near. As Victor Hugo wrote roughly 150 years ago, “Nothing is more powerful than an idea whose time has come.” I may be dead before that time arrives but the accuracy of my past “innovative predictions” gives me comfort that they will happen once the pain of the status quo becomes unbearable. I must simply follow the guidance of Ted Lasso and “believe.”

This column originally appeared in the June 2023 issue of Design007 Magazine.

Joe Fjelstad is founder and CEO of Verdant Electronics and an international authority and innovator in the field of electronic interconnection and packaging technologies with more than 185 patents issued or pending. Download your copy of Fjelstad’s book Flexible Circuit Technology, 4th Edition, and watch his in-depth workshop series, “Flexible Circuit Technology.”