Additive manufacturing technologies have advanced to the point where 3D printing processes and systems have moved outside the laboratory and onto the factory floor. More than 90% of Fortune 500 manufacturing CEOs agree that additive manufacturing will play a pivotal role in their operations in the future, and we can expect greater use of these systems on the production line in a variety of industries. Designing additively manufacturable products is only half the battle—manufacturing engineers also need to consider how the additive manufacturing production line operates and how it can complement existing manufacturing processes.
In the electronics industry, semiconductor and integrated circuit manufacturing have improved by leaps and bounds, and all to keep up with Moore’s Law. Innovation in manufacturing processes on the PCB side has seen less intense innovation, but newly commercialized additive manufacturing systems are set to change this dynamic. With the newer, more advanced additive manufacturing systems currently available on the market, PCB manufacturing engineers can bring 3D printing processes onto the factory floor alongside traditional assembly equipment. Let’s look at what PCB manufacturers can expect to see as more additive systems find their way into the production line.
A high-precision additive manufacturing production line.
The Additive Manufacturing Production Line for Electronics
Bringing additive manufacturing systems onto the electronics production line is intended to replace time-consuming, repetitive fabrication steps, particularly for multilayer PCBs. These processes can run in parallel or in series with other traditional or additive processes for enclosure fabrication, post-processing, and assembly. To increase the throughput of finished boards, multiple printing lines are set up in parallel, and finished boards are placed on an assembly line to attach components.
Proper scheduling, monitoring, and execution of fabrication tasks require that 3D printing systems are connected to each other, as well as to a central command center. This is enabled by new IPC-CFX connectivity standards, which define a standard data format for transmitting information between traditional and additive manufacturing assets. This digital connectivity allows precise scheduling of production tasks and allows engineers to draw from a digital inventory or fully customized designs when preparing for full-scale production.
When a mechanical 3D printer is brought onto the factory, PCBs and their enclosures can be printed and finished in parallel. Both types of systems require little to no retooling, allowing a multitude of different products to pass through a single assembly line. In addition, the costs and fabrication time involved in 3D printing are independent of product complexity. These characteristics of an additive manufacturing production line enable high-mix, low-volume manufacturing and on-demand manufacturing of a variety of complex products with highly predictable costs and lead time.
Once a board is printed and cured, any PCB will need to be passed into an automated assembly line, where components are soldered and the board is secured in its enclosure. Enclosure assembly can be partially or fully automated without major changes to the traditional production process. However, soldering of 3D-printed PCBs requires considering the mechanical and thermal properties of your raw materials, as well as the layout of your board.
Additive manufacturing systems based on aerosol jetting or inkjet printing are ideal for 3D printing fully-functional PCBs, but they can also be used to 3D print certain components. Co-deposition of an insulating substrate and conductive tracks allows capacitors, inductors or coils, and unique antenna arrays to be embedded directly in a 3D-printed substrate. In addition, the ability to 3D print any geometry allows planar components like integrated circuits to be embedded in the substrate. Other surface-mount or through-hole components can then be placed on a 3D printed PCB with standard automated soldering processes.
The challenge in assembling and soldering components on 3D printed PCBs is two-fold. First, the soldering temperature needs to be adjusted to account for the Tg and CTE values of the substrate material and the adhesion strength between the substrate and conductive pads. 3D-printed conductors on polymer materials tend to require lower soldering temperatures compared to standard PCB laminates.
Automated soldering can be brought into the additive manufacturing production line for PCBs.
Second, surface-mount pads must be arranged so that solder points are accessible with automated equipment without bringing the substrate temperature too high. In some cases, through-hole components may be a better option as solder points can be easily accessed on the backside of the board. Due to the temperature constraints, soldering can be difficult with large BGAs, which generally use a heat gun to solder components onto pads. This also becomes more difficult if flat-package integrated circuits are embedded and stacked as the soldering iron needs to maneuver into a tight area. These assembly difficulties are just some design for additive manufacturing points to consider.
As a broader range of advanced materials become adapted for use in additive processes, designers will have the ability to print a broader range of components directly onto the board, which further reduces the number of assembly steps. Examples include organic and inorganic semiconducting polymers, biopolymers, advanced composite materials, nanostructured materials, and much more. Designers can already print fully integrated non-planar PCBs with complex shapes, which allows these designs to compete with chiplets on silicon. The range of products that can be printed in the laboratory and at scale is only expected to expand in the near future.
A mixed traditional and additive manufacturing production line is becoming a reality for a variety of advanced products, including advanced PCBs. The DragonFly LDM system from Nano Dimension is perfect for the production of complex PCBs in-house alongside traditional manufacturing processes for electronic devices. This advanced system allows the deposition of fully-functional planar or nonplanar PCBs, and it can be brought into a production line alongside standard PCB assembly equipment. Read a case study or contact us today to learn more about the DragonFly LDM system.