In cable assemblies, the devil is often in the details — one of which is choosing the right termination for your wires.
Vibration, temperature, and moisture can all impact the reliability and performance of the connections. Temperature fluctuations can cause the materials to expand and contract at different rates, affecting the connectivity between contact surfaces. Shock and vibration can cause connections to become loose, while moisture can increase the rate of oxidation, reducing connectivity and impacting performance.
The two most common types of termination used today are insulation displacement connectors (IDC) and crimping. Selecting the right termination method can help improve manufacturing cost-efficiency, create reliable connections, and ensure consistent long-term performance.
What Is an Insulation Displacement Connector (IDC)?
Also called an insulation-piercing contact, an IDC is an electrical connector typically used to create mass termination connections for flat or ribbon cables. When it pierces through a wire's insulation material, it establishes simultaneous contact with all conductors to create a reliable gastight interface.
IDCs work by mechanically forcing an unstripped wire into a V-shaped fork. Unlike crimping, which requires a relatively high force per contact, a connection with IDC can be established using moderate pressure to push the inside edges of the fork through the insulation materials — in fact, you can create a termination with a simple hand press.
When the connectors deform, each contact surface creates a metal-to-metal connection with the cable assembly. This eliminates the need for removing the insulation before making the connection, reducing the time and labor involved in the manufacturing process.
What Is a Crimp Termination?
Crimping is a common method that replaces soldering techniques for terminating stranded wires. It's done by inserting the terminal into a crimp tool, threading a wire through the terminal, and compressing it under high pressure to achieve metal-to-metal contact. Crimping is best for designs that use discrete wires of multiple sizes in a single assembly.
There are various criteria for establishing a reliable crimp termination. All strands must be sufficiently deformed, but the compression force can't be too light or strong. Care must be taken to maximize cross-sectional contact to ensure performance. The wires must be in perfect working condition, and the insulation must not show any signs of damage. The wires should also have as many strands as possible to optimize crimp density and reliability.
The Benefits of Using IDCs
The main difference between an IDC and a crimp is how the wire is deformed to establish connectivity. While each has its benefits, IDCs are more versatile and preferred for various applications. Here are the advantages of using IDCs:
- They can support a wide range of temperature requirements, from –40 to 125 °C.
- They can handle vibration and withstand up to 50 g of shock.
- They are suitable for both solid and stranded wires in a broad range of applications.
- They create gastight connections to prevent oxidization that can degrade metal wires.
- They save time and money because you don't have to strip insulation from a wire.
- They are easier to install because less force is required to create a termination.
- When a blade penetrates the insulation and makes contact with the wire, it removes surface oxides to create a reliable metal-to-metal connection.
- The ability to create mass termination on flat cables increases manufacturing speed without requiring additional tools or soldering.
- IDCs are cost-effective and reliable alternatives to crimping and soldering, particularly for wires used in power and data applications. Their simplicity and reliability allow manufacturers to connect large volumes of wires at scale with speed, making them the ideal termination option for various cable assemblies.
Need Help? Contact Our Team at JEM Electronics
JEM Electronics has over 40 years of experience in custom cable assemblies, electromechanical assemblies and wire harnesses. To learn more about our engineering services and capabilities or inquire about a specific project, please contact us today.