MULTILAYER PCBS

PCBs power many industries and devices in our society. As technology develops, so does the need for different types of PCBs. As you choose between a single-layer and multilayer PCB, the options might seem overwhelming. It’s important to understand the pros and cons of each option before you invest in a new PCB. Here are some of the benefits of choosing a multilayer PCB over a single-layer design.

WHAT IS A MULTILAYER PCB?

First, it’s important to understand what a multilayer PCB is and how it is manufactured.

A single-layer PCB has one layer of conductive material. You’ll find a conductive wiring pattern mounted on one side of the board and components on the other. Single-layer PCBs are commonly used in simple devices since the available routing space is limited. A double-sided PCB is similar, functioning with more conductive layers than a single-layer board but fewer than a multilayer PCB. It has one dielectric layer and features a layer of conductive metal on both sides.

Multilayer boards, on the other hand, are more complex than a single-layer or double-sided PCB. A multilayer PCB has three or more layers of conductive material. Other layers, often copper foil, stack around the core.

To learn more about the difference between single-layer and multilayer PCBs, see Single-Layer vs. Multi-layer PCBs.

Multilayer PCB manufacturing starts with the core. Partially cured dielectric material, commonly called prepreg, is placed between the conductive layers. Copper foil and additional layers are then combined through a lamination process. Pressure and high temperature are used to bond the layers together into a single PCB structure.

SINGLE LAYER VS. MULTILAYER PCBS

There are many benefits of multilayer PCBs. Overall, these boards can provide more functionality within a smaller area, which makes them suitable for smartphones, computers, or other products that need complex circuitry packed into a smaller space. Here are a few specific benefits:

• You get a greater degree of functionality with multilayer PCBs thanks to the various layers.

• The high assembly density means more circuitry can be incorporated into a smaller board area.

• The construction can be simpler when you don’t need connectors for multiple separate PCBs.

• Multilayer PCB manufacturing typically requires more careful process control and testing.

• The electrical properties and additional routing options of multilayer PCBs can support higher-speed and more complex circuit designs.

• Multilayer construction can be used in both rigid and flexible PCB designs.

In contrast, while single-layer PCBs are highly useful in some applications, they also have some downsides that shouldn’t be overlooked. Here are some of the cons of single-layer boards:

• Because routing is limited to one conductive layer, single-layer boards are mainly ideal for simple electronic devices and don’t offer as much versatility in their use.

• While they cost less to manufacture, single-layer PCBs provide less space for complex and high-density circuitry.

• Single-layer PCBs offer fewer routing options for high-speed and complex circuit designs than multilayer boards.

• Boards with a single layer are confined in their circuit design, as they have only one conductive layer and each connection needs its own available routing path.

While single-layer PCBs are an acceptable choice for low-density designs, multilayer PCBs are often a better option for applications that require greater circuit density and versatility.

USES OF MULTILAYER PCBS

Many industries and products can use and benefit from multilayer PCBs, especially when compact size, functionality, and higher circuit density are required. Here are a few products that often use these boards:

• Computers

• Heart monitors

• Fire alarms

• GPS and satellite systems

• Industrial controls

As you can see from the list, these boards are used for a variety of different purposes. Multilayer PCBs are used across a wide range of industries, from medical instrumentation to testing and industrial equipment. Different industries can utilize multilayer PCBs to achieve greater circuit density, routing flexibility, reliability, and electrical performance.

PICK MORE LAYERS

If you’re debating between a single-layer or a multilayer PCB, it’s important to keep in mind what you’ll use it for. If a single-layer PCB can meet the requirements of the project, then choose that. However, if you need greater circuit density, a smaller board size, more routing flexibility, or more complex functionality, a multilayer PCB may be the better choice.