All About Printed Circuit Design

What is a Printed Circuit Board?

Printed circuit boards (PCBs for short) have made our modern miracles possible - cellular phones, computers, headset stereos, pagers, all would be impossible without something like a printed circuit board. Even televisions and radios would be very different without them. Printed circuits allow manufacturers to connect together all the parts that make up, say, a calculator, very quickly and at a low cost.

Back in the old days, before the circuit board, lots of people worked on assembly lines to hand-wire components together, to make things like TV sets and radios. Eventually, someone decided there must be a better way.

A flat piece of reinforced plastic was coated on one side with a thin film of copper. Holes were drilled in the plastic, and patterns of conductors (circuits) were printed on the copper. Then the whole thing was put into an acid bath. Wherever the patterns were printed, the copper was protected from the acid. Wherever there was no pattern, copper would be etched away by the acid. The result was a pattern of electrically isolated conductors, on a flat "board", on which parts could be mounted and soldered.

Turned out to be a big time saver. Eventually, machines were designed to do the work of putting the parts on the boards, and soldering them as well. Fewer people were needed, and labor costs went down, reducing the price of the TV set or radio. Soon, parts started getting smaller and smaller, and so did the finished products. Nowadays, a hand-held TV set is no big deal, but in 1955, you would have needed a very big hand.

Before long, the printed circuit board began to evolve. Conductors on both sides, instead of just one side. Then conductors were buried inside the circuit board. Conductors got smaller, and closer together. Then someone thought, "why drill a lot of holes and shove little wires through, when we can make parts without wires on the ends, and solder them right onto the board?" This is the basis of surface mount technology, which led to the level of miniaturization we have today - cell phones, pocket-sized CD players, and digital watches.

Printed Circuit Board Designing

Not an altogether bad career choice. Beats the heck out of digging ditches. The working conditions are generally good, and will vary depending on the company (pretty much like any office job). A PCB Designer will usually be found working in a clean, comfortable room, (because the computers need to be kept clean and cool), and often with other circuit board designers, or CAD drafters.

A PCB Designer needs, of course, to know a few things, too. Basic to intermediate electronic knowledge is helpful. It is good to know how to read electronic schematics, and basic computer skills are pretty much a prerequisite. (Wintel / WindowsNT systems predominate in the market, followed by UNIX and Mac platforms). Some drafting education will help, and anything you can do to sharpen your communications skills will be a definite plus. (Determining and meeting the engineer's needs is what it's all about!)

A whole slew of disciplines come together to make up a successful PCB designer. Electronic, mechanical, and aesthetic considerations are all taken into account when designing a PC board. Where will the connectors and switches go? How much room do I have in the case? What kinds of tolerances must I work with? How easy will it be to manufacture the PC board, and how can I make it easier? PCB design is mostly rules-driven. You have to design within the rules, or the board just plain won't work, or worse still, can't even be manufactured. Very embarrasing. Trust me. Voice of experience.

PCB designers often need to be self-starters, detail-oriented, and willing to work long hours, under deadline pressures. (It is often the designer who gets squeezed between the engineer, who wants a little extra time to make sure it's right, and marketing, who are anxious to get out there and sell the thing, before the competition beats them to market.)

PCB design can become a somewhat lonely endeavour, thrashing away hour after hour in a darkened room, headphones clamped to the head, connecting the dots. It is important to create a little balance, therefore, because it can be way too easy to focus on the tasks at hand, and ignore personal lives, excercise, and diet.

A lot of stuff to know. And until recently, there were very few places where you could take classes at the college level, to learn the art of PCB design. It used to be a sort of "fraternity", in which more experienced designers mentored new designers, and taught them how the job was done. That is beginning to change. Because of the rapid growth of the electronics industry, there has been an increased need for qualified designers. There is now an initiative to put into place training and certification programs for PCB designers. Ideally, this will lead to better designers, and better designs.

Salary ranges are anywhere from $18K for a newbie, to $40K and up for a lead designer with lots of experience. Positions can be found in manufacturing companies, and in service bureaus, which provide their design services to client companies.

The Future

The future of PCB design can be summed up thusly: faster, denser, more complex, and more competitive. As chip speeds climb, the need for high-frequency performance increases as well. Designers who are capable of designing these high-speed boards will be highly sought after, and will earn nice, fat salaries.

PCBs will be more jam-packed with parts, and some integrated circuit chips (ICs) are already being mounted directly to the board (chip on board), without the need for a case (package) of its own. More features and functions will be packed into new products, meaning new challenges for packing more circuitry into less space.

And in an increasingly global economy, some American and European PCB designers are finding that they are in almost direct competition with their counterparts in Asia, where wages are very much lower. This is especially true in the area of consumer electronics, where the Asian Dragon is eating our lunch.

Design automation will also increase productivity, and may eliminate jobs. Software tools such as autoplacement and autorouting engines may displace some designers, but at present, there are still many aspects of PCB design that can only be done by a skilled human designer.

The successful designer will need to stay abreast of new technologies and trends in order to remain successful. Designers who are able to offer the most value to the companies which employ their services, will command the highest wages, and the highest respect.