What a Shielded Cable Assembly Is and Why It’s Needed

shielded cable

A cable assembly is a vital piece of modern technology that truly enables the functionality of our electronic systems. From cutting-edge communications systems to high-tech manufacturing facilities, cable assemblies are the humble workhorses that make it all possible. Certain applications call for increased protection like shielding in order to ensure the integrity of data transmission from interference like electromagnetic interference (EMI) or radio frequency interference (RFI). 

In today’s LiveWire cable assembly deep dive, we’ll explore all the ins and outs of shielded cable assemblies to highlight just how useful these can be in a variety of situations.  

What is a Shielded Cable Assembly, Anyway?

Data transmitting cable assemblies require advanced protection from interference that can degrade what’s being sent through their system. Many cable assemblies have advanced protections like hermetic sealing and overmolding, as well as using specific materials like Kevlar when abrasion is a concern. However, how do you protect against external sources that are creating “noise” that can lead to a total loss of the data being transmitted? In walks shielded cable assemblies. 

Sources for external disturbances are many. To complicate matters, there are several kinds of interference and several ways that each can manifest itself. Disturbances are both man-made, as well as natural occurrences. With today’s increasingly-sophisticated electronic systems, it’s likely to have systems running near other electrical circuits or large pieces of automated machinery. Each of these systems has its own transmission of data and electrical currents which can change quickly up and down and generate disturbance. 

Why Do Cable Assemblies Need to Be Shielded?

When the noise that’s generated by nearby electronics actually leads to degradation, it can severely disrupt operations. As we discussed, cable assemblies’ jacketing, insulative, and filler materials can all be modified with a custom blend in order to provide the best protection in a given environment. Waterproofing, adding flexural strength, protection from abrasions—these are great for making a mechanically-sound assembly that functions well in its intended environment but it wouldn’t address any issues related to interference which could still render an unshielded cable assembly useless. 

That’s where shielded cable assemblies can really prove their worth. They are specifically engineered to combat electromagnetic interference. A specialized shielding is used to encapsulate the conductors below which are vital to the effective transmission of data. The shielding can both reflect back the disturbance and/or also ground it. Cable shielding has additional protection engineered specifically to the application so the amount and type of shielding that’s required can vary significantly. Our engineers help our clients look at the specific situation for the assembly to produce the most cost-effective version of the solution. Achieving this over and over again takes the right people, equipment, and intelligence of process. 

With our ability to prototype different types of shielded cable assembly, we apply to test in real-time just how each and every component comes together. If it doesn’t fit within the strict project management timeline and budget we’ve developed with our clients, then we’ll move on to the next solution that does. Quality assurance and quality control (QAQC) is a dedicated science that requires process management engineers to be skilled in eliminating waste and capitalizing on efficiencies. We have found such attention to detail is how you produce shielded cable assemblies that can be depended on no matter what the situation or level of complexity is. 

Different Types of Cable Shielding for Different Applications

Whenever you start to explore your options for shielded cable assemblies, you will likely see one of two prevailing types of shieldings present which are foil shielding and braided shielding.

  • Foil Shielding –  foil is one that uses a thin sheet of reflective material such as copper and aluminum. The foil method generally employs an additional layer of something like polyester synthetic fabric to beef up the overall construction. Foil taping with a material like Mylar can be truly game-changing to help amp up coverage for the assembly from the harmful effects of EMI and RFI. 
  • Braided Shielding –  By weaving together bare strands of a material like tinned or regular copper, you can achieve a great EMI-shielded cable assembly. That’s because the braided cord is a great way to ground the system and provides ease of termination, especially when soldering or using an automated crimp machine as we have at Meridian. The only downside you will find with a braided shield is that they are not going to give you the complete coverage you get with foil. 

Think about how the weave comes together, on a small scale, but there nonetheless, will be small gaps in coverage no matter how tight your weaving is. The tradeoff there though is that braided shields are typically more effective but add size/bulk and cost to the final cable assembly design. 

Interestingly, many shielded cable assemblies rely on both braided shielding and foil/tape shielding. These are best utilized when there are a lot of electronic systems in a confined space, like what you might find at a busy data center.  

How Do You Test Shielded Cable Assemblies?

Testing shielded cable assemblies is paramount to product quality but it takes some dedicated processes and documentation standards in order to do it right. We have held industry-recognized certifications like the ISO 9001:2015 for decades based purely on our level of fanaticism with quality in everything we do. Testing, therefore, is one of the most involved processes you will find at Meridian. 

Even from concept, we’ll be looking at continuity, integrity, polarity, and functionality. This first occurs in a digitized environment while different designs come to life with the help of computer-aided design software. We’ll run virtual simulations on individual components to see which designs best meet the needs of the project. 

Once complete, we’ll typically move forward with small batch prototyping. As we’ve looked at, this helps test the entire process for each design from start to finish. Just-in-time ordering, Kanban, and lean six sigma principles all come into play as we manage logistics, sourcing, manufacturing, testing, and shipping each individual component. The iteration that is most efficient in how it accomplishes every criteria is most likely to move forward with volume manufacturing. 

Last up is a visit to Meridian’s pride and joy – the Advanced Life Testing Lab. Cycles to failure, cable flexing to failure, retraction compliance—no matter what type of test is needed to confirm the data behind each unit’s performance, we make it happen under harsh, real-world conditions. Freezing and scorching temps, moisture, caustic substances, and more await each shielded cable assembly that rolls off the line to make sure it has what it takes to perform exactly as required for years to come.  

Industries that Use Shielded Cable Assemblies

Shielded cable assemblies provide their best benefit in particularly noisy environments or where the possibility for interference could possibly jeopardize the integrity of the data. In either case, industry stakeholders recognize the need for quality cable assemblies produced by trusted manufacturers. 

Shielded cable assemblies keep the modern world running and you’ll find them in just about every industry out there including:

  • Industrial control systems – think of a busy factory floor, a bottling facility, or even your city’s utility systems. Industrial control systems are tight environments, filled with a lot of electronic noise. Cable shielding helps keep each system operating as it should eliminate costly downtime and inefficiencies.
  • Medical technology – when diagnostic or surgical equipment performing well literally means saving lives, the cable assemblies powering these systems simply have to work. A host of additional design considerations play into medical cable assemblies beyond shielding including things like bio-sensitive jacks and specialized strain reliefs.
  • Telecommunications – our society is more connected than ever and relies on a steady stream of data from around the world. Advanced communications equipment like satellites and towers all require complex shielded cable assemblies to make sure data is uninterrupted. 
  • Military, Automotive Original Equipment Manufacturers (OEMs), and many others! 

Depending on what the design calls for, shielding helps to reduce or completely block EMI in a shielded cable assembly. The type and amount of shielding used in each industry is going to vary on a case-by-case basis based on the application at hand. This is where custom cable manufacturers have a steep edge over off-the-shelf cable assembly producers.

Shielded Cable Assemblies Manufactured With Precision

Having the tools and the talent in cable assembly manufacturing is only part of the equation for a truly exceptional experience for your customers. At Meridian, we’ve invested in the quality of both our product and our processes, which include customer service and interaction just as much as the quality of the manufacturing process. When you invest in getting that much better with each and every project you undertake, the results really do start to speak for themselves. Ready to discuss the details of your shielded cable project? Contact our team however is most convenient for you and we’ll start the process of getting you the perfect solution.