Additively Manufactured Electrical Connectors - Are We There Yet?

Numerous industries around us are in the midst of a movement towards electrification. An excellent example of this, and the one likely to have one of the highest impacts on the global market, is the passenger vehicle. Tesla and Cybertruck aside, major automobile manufacturers are contributing to the development of our electric vehicle  (EV) future. Beyond that, automotive OEMs continue to introduce more computer systems, accessories, and other features that rely on electronic interconnectivity to function. Furthermore, new industries like delivery drones and autonomous robots continue to emerge, preparing to surpass the niche category label and enter into the mainstream global market. Widespread infrastructure will be required to support this approaching electrification, which will inevitably create similar growth in associated supporting markets.

As these market shifts continue, more players and products will emerge and electrical connector manufacturers will need to remain nimble to continue to support existing and new customers. OEMs like the four North American connector giants (TE Connectivity, Aptiv, Molex, and Amphenol) may be serving a market that is characterized by a wider range of products that are manufactured at smaller volumes. Electrical connector shells and housings are mostly an injection molded product. In the case of injection molding, the most expensive part and longest lead time tends to be the manufacturing of the injection mold hard tooling. At high volumes, the cost of the tool is amortized over a large volume of parts, and makes excellent economical sense. However, to make a similar part at small volumes, the costly tool can be expensive enough to make a small-batch product run not economically viable. Most EV manufacturers are manufacturing less than 200,000 units per year, with more and more players entering this market. Finding new solutions will be essential to support the growth of these markets.

Fortify’s approach is modeled after fiber-reinforced injection molded plastic parts. Fiber reinforcement in a molded part shows 20-100% increase in mechanical properties such as strength, stiffness, and HDT. This proven uptick in material performance is why the market for reinforced plastic parts continues to grow. Fortify is applying this same methodology to end use manufacturing applications like electrical connectors. By adding reinforced fibers to the right materials during the printing process, Fortify can realize increases in electro-mechanical properties needed for high performance parts while also meeting the economic requirements of small volume manufacturing. 

Small volumes and bespoke solutions are a perfect fit for 3D printing. Employing 3D printing can introduce both cost and lead time efficiencies. Smart and effective implementation of 3D printing onto the factory floor will enable economically viable low volume manufacturing runs and also shorten lead times by eliminating the need for tooling altogether. 

The AM industry has started to engage with this product market fit. Collaborations with 3D printing companies and connector companies have started to see some real progress, however, challenges still remain. 3D printing OEMs are working to find THE breakthrough material + process combination that will eliminate the barrier to full AM adoption for production applications. What’s holding 3D printing back? In the case of electrical connectors, the culprit is a combination of material properties and print resolution. 

Can 3D Printed Connectors Meet Auto Industry Standards

Looking closely at standard automotive electrical connectors, many housings and shells are made primarily from glass-filled engineering grade thermoplastics like PBT, PPS, or nylon. There are no players in the field who can directly 3D print PBT or PPS, but nylon has been available in 3D printing for decades – there are also glass-filled options available. For FDM and SLS, the two major commercial thermoplastic additive manufacturing technologies, there are severe limitations tied to the unavoidable physics of the technology. These processes cannot meet the resolution, surface finish, wall thickness, hole size, and tolerance requirements that are demanded of a commercial multi-cavity electrical connector. Some DLP and SLA solutions have the capability to reach these resolution requirements, but they can not print with the industry-standard thermoplastic materials like nylon and PBT, or match their properties that are critical for this application.

There are DLP and SLA companies working hard to improve their resin formulations that come closer to the high level requirements of electrical connector applications. The ability to print a part that is tough enough to survive several drops on concrete factory floors yet is also capable of surviving extended thermal cycling up to 150℃ is an engineering challenge for photopolymer material scientists. Achieving specific characteristics like high temperature resistance combined with increased toughness can unlock access to big commercial opportunities for applications in aggressive environments – like in an engine compartment or areas exposed to dramatic weather conditions. Chemical manufacturers like BASF, DSM, and Henkel have developed high temperature and V0 flammability rating engineering photopolymers with an eye on tackling the tough automotive electrical connector requirements, but a complete solution is not yet available. If our industry continues to focus on improving material properties in photocurable thermoset systems, we will be able to achieve both the resolution and material properties necessary for electrical connectors. Fortify is working with material partners to improve material performance for production parts, including electrical connectors, to meet automotive (and other industry) requirements. 

With the global shift towards electrification of high value products, and continuous development of 3D printable materials teetering on the precipice of full engineering-level performance characteristics, the market is prepared for a solution. With continued collaboration between the 3D printing material developers and electrical connector OEMS, it won’t be long before we start to see real 3D printed solutions enter into this global market. 

If you have an electrical connector application you would like to explore reach out to us today

This post was written by Sr. Applications Engineer, Phil Lambert.