Estimated reading time: 5 minutes

The Chemical Connection: Changes and Challenges Ahead in PCB Fabrication

What are the most influential changes in PCB fabrication in the next five years? Throughout my many years in the PCB industry, I have witnessed numerous predictions about the industry's future, as well as the introduction of alternative processes that promised to revolutionize the industry.

Most of the more radical predictions have fallen by the wayside, and those alternative processes have failed to produce the predicted results, becoming niche processes at best. My own attempts at predicting where the industry was going—to set up research and development programs for equipment improvements and changes—have usually proved futile, and we’ve ended up with programs that are reactive rather than proactive.

The one set of predictions that has proven constant over the years is that electronic packaging will continue to shrink, and circuitry will become increasingly dense to cram more functionality into a smaller space. For example, my watch now has more computing power than all the Apollo moon lander computers combined. My cellphone can outperform any of the best computers of the late 1960s and early ’70s and still fit in my pocket. The only prediction I will put any faith in is that this trend will continue for at least the rest of the decade. The challenges that present when trying to cram as much circuitry into the smallest space possible will only become more difficult.

I will go out on a limb, however, in predicting that glass substrates may become an important player in the next few years. Lately, we have been involved in glass thinning and etching through glass vias (TGVs), which I wrote about last year, although the activity has slowed down in the past few months. Much to our frustration, samples of laser-shot glass for the test etching of vias have been continually delayed. However, the advantages of glass over standard FR-4 fiberglass substrates (which have almost 10x the interconnect density) are such that their time is coming soon. Things are not moving as quickly as those involved would like, but I certainly expect important movement on this process by 2030. Given the lack of success of my prognostications over the past few years, I hope this is not a death sentence.

What Are the Most Difficult Challenges Ahead?
There are two perspectives to consider when examining the most challenging aspects of PCB fabrication: technical and business. The answer to both is within the question itself. The rapid advancement of technology is the biggest challenge. You no sooner meet one challenge than something comes along that makes that solution obsolete.[ML1]  As an equipment supplier, it is challenging to stay ahead of the curve and be proactive rather than reactive. It is desirable to be ready for the next wave of technology but that is difficult to do when the next wave of technology arrives before you’re finished with the previous wave. Even when the technological change is relatively slow, the degree of change can be unanticipated.

A good example is transport technology: transporting the circuit board on a horizontal conveyor through an etch chamber where we spray it with hot acid that is much heavier than water (specific gravities between 1.22 to 1.48 vs. 1.00 for water).

When I started in 1974, the typical circuit board had a 0.062" core of FR-4 fiberglass, and our conveyor system had one-inch diameter wheels spaced two inches apart on thin titanium conveyor rods, with the conveyor rods also spaced two inches apart. This was designed to transport a rigid panel through the etcher with minimum interference to the lower sprays.

A customer brought in a test sample with an 0.010" FR-4 core. It was a disaster because the 0.010" core was flexible enough so that the signal-over-signal layers would slip between the conveyor rods into the etcher sump. This necessitated a change to the conveyor design, where the rods were spaced closer together, and the wheel diameters were increased, allowing them to overlap from rod to rod and prevent panels from slipping between them. We called it the “ultra-thin” conveyor (and still do) because we wondered how much thinner they could make a fiberglass core. As it turned out: much thinner. It wasn’t long before we saw 0.002" FR-4 cores that forced us to move the conveyor wheels closer together for support, leading to a slight slowdown in etch rate (blasphemy at the time, but it had to be done).

That was acceptable because they certainly couldn’t make fiberglass cores thinner than 0.002", but they could use materials like Kapton and Pyralux, which were not only thinner but also flexible. These materials would transport okay, but the weight of the etch solutions tended to emboss creases into the panels from the wheel rims, forcing us to increase the width of the wheel rims to provide still more support, but also slowing the etch rate a little more.

Now, I am trying to anticipate even more flexible materials and come up with a conveyor system that will run substrate material with the thickness and flexibility of tissue paper up to boards with thicknesses of 0.25" and more in the same equipment. It goes without saying that using leaders taped to the leading edges of flexible panels is not an option. I would like to think that I can come up with a solution that also addresses future transportation issues. The problem is that I can’t conceive of any material that will be more difficult to work with than what we have already. At the same time, I’m confident that someone will come up with something.

In short, it’s hard to predict or prepare for changes that haven’t even been thought of yet, but the escalating rate of change in the industry makes these changes inevitable. We will be forced to continue reacting to these changes rather than anticipating them.

This column originally appeared in the January 2026 issue of I-Connect007 Magazine.