Are you interested in finding out what a consumer PCB is? Did you know that the printed circuit board (PCB) has been crucial to the existence of many modern electronic devices that we take for granted every day? Would it surprise you that printed circuit boards are essential for many types of technology in various industries like automotive components used in vehicles, monitoring equipment in the medical field, industrial equipment used in manufacturing, telecommunications devices, missile detection systems in military applications, and more?
Among the many fields where printed circuit boards play a role, none of the ones mentioned above come close to the sheer scale they play in the consumer electronics industry. Let’s find out the early history of printed circuit boards, what goes into making modern consumer electronics PCBs, and why they are so vital to your daily lives. We’ll also go through the advantages and disadvantages of using consumer electronics PCBs.
A Brief History Of Printed Circuit Boards
Before the printed circuit board (PCB) was first invented, electronic circuits were made up of electronic components that were mounted onto a chassis by insulating material. The chassis itself was normally made from a sheet metal frame with a wooden bottom. The electrical components were then connected to others using copper wire which had to be soldered, or through crimp connectors.
As you can undoubtedly guess, this point-to-point wiring process was done by hand, making it a slow and labor-intensive process. Not only was this manufacturing process very slow and expensive, but the circuit boards were also extremely bulky and fragile. This was made even worse since some circuit boards still included vacuum tubes that had glass envelopes. This made portable electronics that were reliable and safe to carry an impossibility.
Early Printed Circuit Boards Developed For Military Use
Like many other types of consumer electronics and components, printed circuit boards found their early use in military applications like radio communication systems during the second world war. The printed circuit board was first invented in 1936 by Austrian engineer Paul Eisler, who used it to make a radio set. Multi-layer PCBs were used throughout the war by the German navy for mines.
In the early 1940s, the United States military needed a circuit board that could be mass-produced and also withstand being fired from a gun to be used by proximity fuses for their shells. The supplier Globe Union proposed using a ceramic plate that was screen printed using metallic paint. The paint would act as the conductor to electrically connect electronic components, with carbon being used as the resistor. There were still subminiature vacuum tubes present as well as ceramic disc capacitors to complete these electronic devices.
The technique worked but it would take a few more years for the US military to release this technology to the public. The manufacturing process of having conductors, and other passive components on a common insulating ceramic substrate material would later revolutionize the consumer electronics industry. It would also be a major invention that would pave the way for more advanced integrated circuit technology of the future.
PCBs Enter Consumer Electronics
The early PCB design was based on through-hole components. This meant that holes needed to be drilled on the circuit board to accommodate each component. The wires connecting PCB components were inserted through these holes and soldered to the copper traces.
Auto-Assembly Process
In 1949, Moe Abramson and Stanislaus F. Danko invented a method where the copper foil was used to make an interconnection pattern. The electronic components were inserted into this copper foil and dip-soldered. This was later replaced by an automated method called ‘wave soldering’ where the circuit board was passed over molten solder paste to make contact with the desired components. After lamination and etching methods were developed, the groundwork for manufacturing processes that would continue to be used and evolve for decades would be laid.
After these techniques were released by the US military for commercial use in the late 1940s, the consumer electronics industry really took off in the following decade. Motorola was one of the first to get involved and used the new technology in their home radios in the 1950s. Some of the earlier point-to-point chassis remained in use until the late 1960s, but PCBs did manage to bring significant improvements to consumer electronic devices by reducing their weight, bulkiness, and costs.
Surface-Mount Technology
By the 1980s, the outdated through-hole components were going out of fashion as electronics products were increasingly built using the PCB surface mount technique. Surface mounting allowed smaller components to be connected, which not only reduced the size of printed circuit boards but also enabled more components to be fitted onto a single board. This was a huge boon to portable electronics.
Surface mounting also allowed consumer electronics manufacturers to attach components to the top and bottom sizes of the board, creating double-sided PCBs. The only downside to the surface-mount method was that maintenance was more challenging. However, the reduced size and lowered cost of production far outweighed this downside, and the method was vital to the success of the consumer electronics industry.
PCBs With Multiple Layers
The next advancement of consumer electronic devices came in the 1990s as printed circuit boards started using a multiple copper layer design. Multiple copper layers made maintenance even more difficult, but the benefits like the ability to support a higher density of PCB components made even smaller and more portable electronics possible. Since this manufacturing process was less costly than earlier methods, it became cheaper to simply replace a faulty circuit board than to repair one.
High-Density Interconnect PCBs
Modern PCBs are used in nearly every type of consumer electronics device like smartphones, televisions, laptops, portable speakers, digital cameras, and pretty much anything electronic in your home. You can even get your own custom PCB manufactured to your design specifications and circuit layout to build your own homemade electronics devices.
How The Modern Consumer Electronics Printed Circuit Board Is Made
The type of PCB design used in modern electronics has a flat sheet of insulating material which is the substrate layer. FR-4 glass fiber reinforced epoxy resin is the usual type of insulating substrate used today by the PCB industry. Laminated to this substrate is copper foil. Etching is the process that is used to divide the copper into lines called ‘circuit traces’ which are capable of conducting an electrical current. These circuit lines are essentially the wires of the printed circuit board and are separated by the substrate.
This etching is done by coating a photoresist onto the surface of the PCB and then exposing the surface to light. The light is projected as a pattern that represents the copper circuit layout. This pattern is called ‘the artwork’. The exposed copper is the excess copper that has to be removed during the etching process, leaving only the desired layout of circuit traces. The copper thickness can affect heat dissipation and is increased when needed to handle higher currents.
Apart from removing the unwanted copper to make the traces, etching is also used to develop the copper pads used for connections, and vias that connect between layers of copper. Similar methods are used in the manufacture of semiconductor electronic products.
The solder mask is the protective coating applied to the PCB that is there to prevent corrosion of the copper. This also prevents the signal traces from accidentally shorting if it comes into contact with stray bare wires. The solder mask is also what gives PCBs their green color, although this can be changed if required. The circuit board is then marked using silkscreening ink to indicate where the electronic components are supposed to be mounted.
The circuit components are precisely mounted using robotic motion control systems and then soldered. Automated optical inspection is done for quality control at multiple stages of production to detect any manufacturing defects in the PCBs. After passing the automatic optical inspection, the electrical performance of circuit boards is verified using automated test equipment which can handle large volumes of boards and are capable of detecting various issues like missing components and shorts.
Finally, the circuit boards are packaged and sent to manufacturing and distribution centers to be used in the production of consumer electronics, or even directly to end users who build their own equipment.
Advantages Of The Consumer PCB
Printed circuit boards have been vital to the evolution and widespread use of modern consumer electronics. Starting from the earliest handheld transistor radio to the latest iPhone, portable electronics have much to be thankful for printed circuit boards. Let’s find out what makes PCBs so advantageous for consumer electronics applications.
Compact Size
One aspect that portable electronics definitely benefit from is the compact size of modern consumer PCB design. The copper tracks provide the circuitry between tiny components that would otherwise be impossible to achieve using the bulky wires that were used in the past. With high-performance microchips used in the latest consumer electronics devices getting smaller and more advanced, the ability to surface mount them on PCBs, and to mount them more densely allows for more computing power in a smaller package.
Easy To Diagnose And Repair PCB Components
PCBs normally come with components and their polarities are clearly labeled on their boards. This makes it easier for technicians to diagnose a faulty device. It’s easier to identify which components have failed, and to replace them, making the repair of consumer electronic devices a little simpler.
Portability
Aside from the compact size, the PCB components are tightly connected to the board through the solder paste. This means that while the device or PCB is carried around, the actual components stay fixed securely in place. Since the copper tracks are created through an automated process, PCBs are highly unlikely to exhibit loose connections within the board circuitry itself. This makes them perfect for portable electronics.
Low Noise
No electronic device is immune to electromagnetic interference which can cause noise in the signals that pass through them. However, PCBs can be designed so that their circuit layout provides the optimum path for the signal to travel, reducing the amount of interference they can pick up. Crosstalk between components is also reduced as much as possible. When properly designed, reliable PCBs that deliver high performance with low signal noise are possible. Telecommunications equipment PCBs, aerospace equipment, and devices used in computer technology sectors all benefit from this.
Easy To Mass Produce
With today’s latest manufacturing equipment, PCB production can be scaled to supply the large demand that exists in the consumer electronics industry. The processes behind PCB manufacturing are very well understood, highly streamlined, and reliable, making mass production feasible at relatively low costs.
Disadvantages Of The Consumer PCB
While the consumer PCBs are great for making portable electronics, they do come with a few disadvantages that must be noted.
Damaged Circuit Boards Are Hard To Repair
While it is easy to diagnose, identify faulty components, and replace them to make the PCB work as intended, it is extremely difficult to repair if the board itself is damaged. In fact, most people don’t even bother to repair a damaged board and will recommend simply replacing the entire board with a new one. This can be costly.
PCBs Are Built For Specific Use Cases
A printed circuit board can perform its intended function without any issues. However, it can rarely be programmed to do something else. For example, the PCB used in a digital camera is unlikely to be useful as a circuit board in a portable Bluetooth speaker. The components simply do not allow this.
Environmental Concerns During Disposal
The manufacturing of PCBs is energy intensive. Furthermore, when a PCB becomes faulty, it becomes a useless waste product that requires careful processing to be safely disposed of. Two million tons of waste products are created every year due to PCBs, and separating the metals from the boards through incineration will result in toxic gases. Using acids to do the same, will end up with acidic water byproducts. The future of PCB design and manufacturing lies in developing new methods to reduce this type of impact on our environment.
Types Of Printed Circuit Boards
Many types of PCBs differ based on the substrate, the number of layers, and the signal frequency used. Single-sided PCBs made with a thin layer of copper are the most common and used to build simple circuits found in relays, power sensors, and even toys. High-density interconnect PCBs are used in complex consumer electronics devices such as smartphones, laptops, and digital cameras.
When looking beyond consumer electronics, radio frequency PCBs can range from simple ones used in mobile phones to radar jamming systems used in military applications. There are rigid-flex PCBs that combine the characteristics of both rigid and flexible PCBs. The rigid-flex PCBs are designed to save space and are lightweight. They are often used in medical and military applications.
Solar power cogeneration equipment and power equipment such as DC to AC inverters also include specially designed PCBs. Safety and security equipment like surveillance cameras, smoke alarms, and carbon monoxide detectors use them as well. And finally, lighting systems based on light-emitting diodes (LEDs) require PCBs. Everything from automotive and computer displays to residential and commercial lighting applications uses this technology.
The Future Of The PCB
The PCB has been around for decades and yet the market is not showing any signs of slowing down. As new technologies like artificial intelligence, the Internet of Things, and the latest consumer electronics all depend on PCBs, the demand is expected to grow. 3D printing and more environmentally friendly methods are expected to be developed in the coming years.
Biodegradable circuit boards and environmentally friendly etching chemicals promise a future where over 90% of the copper used in the boards can be recycled. This means that the outlook for the consumer PCB market remains very bright. To learn more about consumer PCBs, semiconductors, and manufacturing, visit Inquivix Technologies today!
FAQs
A printed circuit board that is used for consumer electronics applications like smartphones, digital cameras, televisions, video game consoles, as well as all manner of home and kitchen appliances. Furthermore, consumers can also get custom PCBs printed for homemade devices.
Single-sided, double-sided, multi-layer, high-frequency, LED, radio frequency, rigid, flex, and rigid-flex PCBs are all examples of the different types available today.
