Printed circuit boards (PCBs) can be classified based on many things, including their fabrication process, application, or design specifications. When choosing a PCB, factors such as stress, mechanical strength, electrical stability, and space constraints must be taken into consideration. Single-sided PCBs and double-sided PCBs are two such classifications that are based on which side the conductive copper and components are on. Space constraints, cost, and circuit density are factors that designers must consider when choosing between single-sided PCBs and double-sided PCBs. In this article, we will compare single-sided PCBs vs. double-sided PCBs and explore their appropriate applications.

Single-Sided PCBs
PCBs are used in the electronics industry to connect electronic components. Components are soldered on a PCB and are connected using conductive copper. A single-sided PCB is a type of PCB where the components and conductive copper are mounted on one side and the conductive wiring is on the other side. Single-sided PCBs are the first-ever printed circuit board technology and are widely used due to their simplicity in manufacturing.

A single-sided PCB consists of a substrate layer, conductive metal layer, protective solder mask, and silkscreen. The conductive copper layer is laid above the substrate layer. Electrical components are soldered on one surface of the board and the circuit is etched on the other side. As single-sided boards use only one conductive layer, there is no intersection or overlapping of conductive paths. Circuit realization using a single-sided PCB consumes a lot of space and is suitable for low-density circuit designs.

Single-sided PCBs are widely used in camera systems, calculators, radio equipment, power supplies, timing circuits, LED lighting boards, and printers. Single-sided PCBs are good for low-cost electrical or electronic circuit realization. However, circuit designers might struggle to create single-sided PCBs to realize complex circuits with space and size constraints. For such boards, a double-sided PCB is the best option.

Double-Sided PCBs
Single-sided PCB traces are present on only one side, while double-sided PCBs have traces on both sides with top and bottom layers. The components and conductive copper are mounted on both sides of a double-sided PCB, and this leads to the intersection or overlap of the trace. Double-sided PCBs are best for realizing high-density circuits that do not require point-to-point soldering.

In double-sided PCBs, there is a layer of conductive copper on both the top and bottom sides of the board. Vias are introduced to create traces on both sides of a double-sided PCB. The vias help in connecting the components between the top and bottom layers. Double-sided PCBs use two mounting technologies, through-hole technology and surface mount technology, for connecting the circuits on either side.

Through-hole technology: Leaded components are installed into pre-drilled holes on the double-sided PCB. The leads of the components are soldered to the pads on the opposite side.

Surface mount technology: Surface mount devices (SMDs) are precisely placed on the surface of double-sided PCBs.

Double-sided PCBs are often used in vending machines, cellphones, UPS systems, amplifiers, lighting systems, and car dashboards. Double-sided PCBs are best for higher technology applications, compact electronic circuits, and complex circuits. As the complexity of a circuit increases, the PCB type shifts from single-sided to double-sided to multilayered. Double-sided PCB production is also more complex than single-sided PCB production.

Below, we have a summary of single-sided PCBs vs. double-sided PCBs.

Designers must be well-aware of circuit space constraints, mounting technology requirements, and circuit density to decide between single-sided PCBs vs. double-sided PCBs. To design single-sided, double-sided, or multilayered PCBs, Cadence’s PCB design and analysis tools can be utilized.