What is a 3D Printed PCB?

A 3D Printed PCB is a circuit board created using 3D printing technology, where conductive and insulating materials are deposited layer by layer to build the board. 3D printed PCBs overcome traditional production limitations, taking the manufacture of electronics to advanced capabilities. This emerging technology enables faster and more flexible production of circuit boards compared to conventional methods. Functional PCBs could be made in just a matter of hours using 3D printing, allowing for much faster design cycles, rapid prototyping and making custom PCBs for unique electronic products (especially for military or aerospace applications). This technology can also help mitigate supply chain problems, such as plant shutdowns or shipping delays, by making it easier, faster and cheaper to produce boards in-house, reducing dependency on external suppliers.

Currently, 3D printing technology is only used for low-volume production and more R&D is needed to scale it to mass-production levels. Recent advancements have already allowed manufacturers to disrupt traditional electronics manufacturing a little by enabling accelerated speed to market for new products.

Methods of 3D Printing PCBs

There are two methods that are generally used to 3D print PCBs: printing a substrate board with hollow channels or trenches that are later filled with conductive materials or printing the circuitry with conductive materials on a pre-fabricated substrate.

Method 1: Printing Board (Substrate) with Hollow Traces

This method of 3D printing of circuit boards involves designing and printing a substrate board with hollow channels to hold the conductive material. This process produces a "shell" that can be later filled with a conductive substance. In this method, the board is printed using nonconductive filaments like Acrylonitrile Butadiene Styrene (ABS) or Polylactic Acid (PLA). The filament is melted and deposited by the machine layer by layer under the control of software. These boards can be made using any commercially available 3D printer with sufficient accuracy.

Method 2: Printing Conductive Materials (Traces)

In the second method, the 3D printer lays down conductive material in the exact shape of the circuit (traces) on a pre-fabricated substrate. The substrate can be either fabricated using the 3D printing method discussed above or using traditional fabrication processes. Hence, this method can also be used to produce even flexible and rigid-flex PCBs. The conductive materials are usually available as inks or filaments infused with conductive particles, such as silver, copper, or graphite. These materials can also be applied in other ways, such as in the form of an aerosol spray which is usually how conductive inks are applied.

Inks are the more commonly used option in commercially available PCB 3D printers. These 3D printers operate in a similar way as a general-purpose inkjet printer to deposit droplets of both conductive and insulating ink to build the circuit traces. Some printers require a prefabricated substrate board, while others can print the entire board from scratch. The ones that 3D print the substrate board by itself can produce complex multi-layer and double-sided circuit boards that may even be embedded with electronic components.

Fused Deposition Modeling (FDM) printers can be used to deposit conductive filament in the shape of the circuit. As FDM printers are the most widely available type of 3D printers, this method is very cost-effective. However, they produce bulkier and less efficient circuits than ink-based 3D printing. Therefore, conductive filaments are not suitable for commercial operations, but they can be used for PCB prototyping.

Advantages

3D printing is a cost-effective method of PCB production, requiring minimum raw materials, producing minimum material wastage and does not have shipping or outsourcing expenses. 3D printing produces PCBs much faster compared to the conventional processes. Additionally, 3D printing also supports the production of flexible or rigid-flex PCBs and circuit boards with complex shapes and designs. This method can produce highly compact circuits and also encourages on-demand manufacturing, hence reducing inventory management problems and supply chain risks. 3D printers achieve higher accuracies in PCB production than traditional methods, especially when producing high-layer count PCBs. Some printers can even place components, further reducing the possibility of human error in the production process.

Disadvantages

As a relatively new technology, 3D PCB printing doesn’t yet have an extensive range of suitable materials. Conductive materials used in 3D printing still don't match traditional ones in terms of electrical performance, although they’re being constantly advanced. Size constraints of the printer's build chamber can limit the production of larger PCBs. Currently, few companies exist in the current market that are manufacturers of commercial 3D PCB printers which limits consumer choices. Many printers are also designed to support one or two types of materials from their manufacturer, which can increase costs and limit design choices.