Estimated reading time: 5 minutes

Consider This: PCB Technologies We Need Now and Later

RF high-frequency circuits are in almost every vehicle being produced today, with side, front, and rear radar to warn of potential collisions. Specialized RF technology high-frequency PCBs are in high demand.

Newer flex designs for automobiles are used in many areas: seat wiring, dash, and even replacing hard wiring within the car. Flex lays flatter, takes up less room, and weighs less than hard wires.

Heat PCB IMS is experiencing a large rapid growth in LED lighting, cars and homes, and even streetlights. Power circuits are utilizing IMS to shrink the size and control heat. IMS allows for more current through smaller track widths and eliminates some heavy copper traces.

Higher-frequency laminate with lower Dk and very low-loss Df will be used for 5G. The new 5G system will be the go-to technology for controlling communications and even machine control, offering wider band width, higher speed signals and more computing power in a smaller package. The PCBs which will be used will need to be able to handle 5 GHz frequencies, requiring new types of laminates.

Artificial intelligence is here, from autonomous cars to automated factories. It is potentially the biggest thing to change your life and our PCB business. Smart computers need not only fast, high frequency PCBs, but they need all the sensors to send the signals to the AI computer which they need to understand and to know the world which they control. It is all here and ready to explode.

As a side note, I used an AI feature to properly spell “autonomous.” Now my computer is sending data because I used Word’s Smart Look-up feature to find the word “autonomous” and my Google pages will be filled with ads for AI. It’s pinpoint sniper advertising, only aimed at me. All the advanced AI electronics on PCBs allows them to identify my inquiries and target only me with those ads. I found this out a few weeks ago. I checked Word to get the correct capitalization for a Raspberry Pi computer. The same day, I was suddenly getting four to six ads per page on Google for Raspberry Pi computers. Coincidence? I think not. I was specifically targeted. The ads were sent to only me out of billions of internet users, and this part scares me the most.

The point is that a huge number of PCBs were involved in allowing them to target an ad to only me. From my home PC and the internet router box, to a box outside my home and the 20 or more routing computers on the internet, all that information is sent back to some advertising company. Then, the data goes through a computer that “knows” to send me the ads they wanted me to see. It took a few hundred PCBs with powerful computers to achieve the feat. Our industry is only too happy to sell all the PCBs needed to make this targeted ad propaganda work.  

The average size of a PCB has decreased greatly. A few years ago, a small PCB was 50 square inches. Today, most PCBs measure only a few square inches, and many are much smaller. In one reality, we are using much more laminate, but we are making many smaller PCBs.

These small PCBs are in smart watches, small RF radar units for your car, and every one of the billions of LED light bulbs; if you look carefully enough, you will find the tiny PCBs everywhere. However, many PCB shops are not specifically set up to manufacture very small PCBs with large spaces between individual PCB parts to allow for router bits to cut them. A smart move would be to design your shop panels to use every little bit of space and use laser or die cutters to increase the number of PCBs that you can squeeze onto a panel.

Conductive silver or tin on glass is a specialty market. With every one of the billions of phones utilizing this technology, it is a massive market all to itself. It utilizes specific plating baths and special imaging and etching equipment. Many of the tiny, overlapping traces are actually screen-printed silver and clear insulative inks. It is expensive to set up, however, the volumes are tremendous.

Ultra-thin multilayer is a quickly growing technology, utilizing thin glue sheets and very thin laminates to produce eight layers, under 20 mils thick. The thin circuits are in cellphones, computers, and a lot of other very small devices. A surprising amount of technology fits on these little circuits, such as hearing aids controlled by your smartphone.

3D printing will be the big disrupter to change the PCB business. They are now quickly printing stainless steel, titanium, copper, and other metals as well as dielectric bases. The 3D printers are already making FR-4 type laminates. Once the technology is sorted out, 3D printing of a PCB will be upon us quickly. Recent changes in the technology have improved speed by 20 times and lowered cost by 10 times. Soon we will see real 3D-printed circuit boards.

Two other technologies that are quickly growing are heavy copper and high voltage PCBs. Spurred on by the electric car and transportation gold rush, both types of PCBs are needed in large quantities. The high voltages of the batteries at 300–600 volts, and the massive currents to drive the motor, require significant thick copper traces on the driver PCB and superior laminates with high voltage dielectric properties.

Embedded components are a newer technology that allows more components to be placed on and inside a PCB. Having resistors and capacitors inside allows for more chips and larger components on the two outer layers. It is even possible to insert physical resistors and capacitors in very small sizes. The alternative is to print the components inside, using resistive or capacitive laminates.    

There are so many new technologies within the encompassing dome of PCB manufacturing that for any one single PCB shop to know everything about each specialty technology is getting harder and more difficult to manage.

This column originally appeared in the February 2021 issue of Design007 Magazine.