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The Bleeding Edge: The Future of the PCB

With all the recent replies and counter-replies to Ray Rasmussen's column about the future of the PCB, I decided to pull out my dusty crystal ball and peer into the future - and the past.

First, all the recent comments are, in a way, accurate.

As Doug Brooks states in his column, the number of functions per PCB is a less important measure than the number of PCBs per box. But Ray Rasmussen's original column is accurate in saying that the PCB is now in danger of being replaced by printed electronics and complete silicon circuits. 

So I gaze into the crystal ball (this one can look into the past), and I see a horse-drawn buggy, and hundreds of factories making buggy whips. Then a belching, smoking one-cylinder car drives by at 5 miles per hour, and the president of a buggy whip company says, "The automobile will never take off. It's too smelly."

When the smoke clears, I see only one buggy whip company and hundreds of auto parts manufacturers.   

Now I see a silicon chip attached to a display. I see someone typing on that display. What I don't see is a PCB. Maybe the darned thing is broken again. Farther off in the future, I see a computer made up of a single chip with no other parts and no PCB in sight. It's mind-activated and attaches to the side of your head. OK, this is getting weird, even for Bleeding Edge.  

But what I do see is a future built upon this fact: The silicon chip business has been advancing at the rate of Moore's Law, while we in the PCB business have been - largely - stuck in neutral.The huge advances in chips will initially lead to more products bearing more PCBs, but we will one day see the death of PCB as we know it. Just think back 10 years ago, when almost every electronic device featured some sort of PCB, be it traditional FR-4, flex, membrane or HDI. Today, the list of products that once used PCBs but are now PCB-free would take many pages. This list includes products like the new tire pressure sensor that is based on MEMS technology and packaged on through-hole silicon to include energy harvesting. New automobile LED light switches attach to the LED in the turn signal or head light, with a silicon base chip packaged without a PCB on a ceramic heat sink.

Even printed electronics are not safe from direct chip replacement. A new RFID chip is fully functional and, at the size of this comma, it will replace the typical silver printed RFID tag.

I took part in an R&D exercise to determine whether the PCB could be eliminated from a laptop computer. We found that it was not that difficult to design around and remove the printed circuit board. By using "angel technology" in which most of the calculating functions are done on the Internet, we eliminated most of the parts. As the laptop got simpler by removing parts, we foresaw the ability to put all the chips, components and even the switching power supply on one big stacked silicon base wafer. Again, no PCB was required, because we had very little interconnect to contend with.

The demise of the PCB will not be a sudden event, but more of a chipping away at the edges. Printed electronics will remove some PCBs as it progresses in its evolutionary journey. MEMS technology will chew off another small slice, as will MCM technologies working with direct connection to touch-screen devices. The single biggest chunk to be taken out of PCB production will come from the growth of the super all-in-one single chips - MCM chips on steroids. The packaged silicon will feature all the components, computing power and memory needed, and it will not require a PCB to interface with the device.   

Cell phones in the near future, i.e., 8-10 years from now, will have three times the functionality they do now, and with no PCB. All of this does not signal the demise of the PCB industry, but the business will change.

There will still be companies whose products need a PCB; many companies simply won't have the millions of dollars needed to design and R&D a super MCM. Those companies will stay with the conventional PCB, but you can expect the size and line width of the PCB to continue to shrink.

Anyone want to buy a buggy whip company? I understand the new buggy whips feature LEDs that light up to help prod the horse along. The LEDs are powered by energy harvesting and driven by computers. That should increase buggy whip sales!

Robert Tarzwell is CEO and founder of DMR Ltd. He can be reached at rtarzwell@megadawn.com.