IDC Connectors Overview

IDC connectors, an acronym for insulation displacement connector, have become very common electrical connector types, used in a wide variety of different applications. They are common in industrial applications, where the accuracy of connections, the ability to make them reliable and where there may be many wires that need to be connected at once are all vital considerations.

There are different designs of IDC connectors used throughout industry. Some of them are designed to be used on ribbon cables, some are designed to be used on telecommunications equipment and others are actually blocks, which make it easier for technicians to arrange cables on a large panel.

These are such common components that they are made by most major manufacturers. RS, Molex, Phoenix Contact, 3M, Harting and other suppliers are among the names that produce these products. They come in different material options, in different designs for specific mounting needs and with many other options, making it easy to find one of these solutions for the vast majority of industrial wiring needs.



An insulation displacement connector both makes connections more reliable and reduces the amount of time required to terminate cables in the correct way.

Rather than individually stripping each wire to make a connection, a technician only needs to insert the wire into the insulation displacement connector. The device is outfitted with its own blades.

The blades are arranged so that the sharp portions are positioned exactly where the cables will lie in the device. When the cable is placed in the device, the blade is brought into contact with the wire, usually by simply pressing down on the device. These blades go through the insulation and connect to the wire.

This connection is made very reliably every time. The blade of the device will weld itself to the wire. There are no gases present in the connection once it is in place.

Initially, insulation displacement connectors came out of the telecom industry. The first designs worked with single-strand wires. Eventually, however, these types of connectors were developed so that they could work with multiple strands of wire. This makes them particularly useful in computer technology, where connections between multiple strand cables need to be made quite frequently and where making the individual connections would be particularly laborious.


Related Products

IDC connectors are sometimes used with associated accessories that make creating the connections even easier.

In punch down applications, see below, a punch down tool is usually employed. These devices make it easy for the builder to get the wire into the correct position in the IDC and, in some designs, the device will actually trim the wire at the same time that it inserts it into place. This helps to keep the connection very neat and clean and, of course, drastically speeds up the process of making these connections at all.

For applications where connectors are being added to the end of the cable, a specialized crimping device will usually be employed, designed to accommodate the size of the connector and allow it to be compressed without damaging it. This will actually provide the mechanical force that sinks the blades into the individual strands within the cable, forming the connections and sealing the connector onto the end of the line.

Some of these connectors, however, require no specialized tools. Ribbon connectors, for instance, are often simply placed on the end of the cable, the ribbon cable positioned correctly and the connector is fastened into place by pressing on it with the fingers until it clicks shut.

While many of these connectors can be utilized without special tools, having the tools to go along with them makes it much easier to use some designs. In some cases, it may be necessary for getting connections to be as reliable and durable as required.



There are several different variations on IDC connectors, each of which is typically associated with a specific usage.


Telecom Applications

IDC connectors have their origins in and are still used in telecom. In telephone applications, they are used with registered jacks, which usually involves a similar process whether the cable being used is Ethernet cable, telephone cable or any other type of related cable.

The cable is typically stripped of its outer shielding. This exposes the individual strands within the wire. The strands are placed in the insulation displacement connector in specific arrangements and the device is crimped shut. As the device is crimped shut, the blades make contact with the wires, forming the connection.

In some cases, the person making the connection may have to arrange the wires in the cable in a configuration that is not the same as the way they are arranged within the cable. Creating crossover cables and other types of cables, for instance, can be done by changing the order of the wires in the connector, making these types of connectors very versatile for networking purposes.


Patch Panels

Patch panels are made of what are called punch down blocks and are widely used in the telecom industry. These contain an IDC and the wire is inserted into place using a specialized tool. These are very commonly used in multi-line telephone systems and provide a very easy and reliable way to make connections.

In networking applications, hubs and switches designed to receive the proper RJ connector are generally used in place of punch panels.


Computer Applications

IDC connectors are likely familiar to anybody who has seen the inside of a computer. They are widely used in building computers, providing the most convenient and reliable way to make connections between complex cables that network peripherals, power supplies and the other components of computers together.

These are commonly used with ribbon cables, the flat, wide spans of cable that connect the devices within a computer. The primary advantage of utilizing IDC connectors in these applications is the fact that they can consistently make the connections needed very quickly. Using these connectors can drastically reduce the amount of time it takes to connect devices within a computer and have become the standard for the industry.

Because these cables are typically very wide and complex, the IDC itself will usually be marked so that the user can determine which wire needs to be placed in which position. On most ribbon cables, there will be a red stripe running along one side, indicating the Pin 1 position. This makes it easy for the builder to ensure that they are connecting the ribbon cables correctly and the connectors themselves provide very secure connections between the motherboard and the cable or peripherals and the cable.

IDCs are used for many different types of cabling within a computer. Parallel cable, SCSI cable, disk drive cable and serial cable commonly employ these types of connections. One of the advantages of this is that the connectors are generally used in a way that prevents the wrong device from being plugged into the wrong socket on the motherboard. This can ensure that potentially dangerous mistakes aren’t made and, of course, makes it easier for builders to assemble computers.



In applications where IDC connectors are used, the proper sockets will have to be used with them. Other components, such as headers and other replacement parts are also available from suppliers.

In networking applications, some connectors are supplied with IDC connectors integrated into the device. For example, on the wall plates designed for some network connections, the back of the device will have a punch down system on it, allowing the builder to easily insert the wires in the correct positions and connect them.

In most cases, the connectors and sockets used with IDC connectors are only compatible with one model. This makes it much easier to ensure that everything is being connected as intended.



These connectors are so common that they come in a staggering variety of different options. For example, IDC connectors can be purchased with contact materials made out of beryllium copper, copper alloys, phosphor bronze, brass and copper nickel tin alloy. In addition to choosing the material for the contacts, the contact plating can be made out of precious metals like gold and palladium. More common metals such as nickel and tin are also used to make the contacts. In many cases, these materials are alloyed to offer specific characteristics.

While these types of cables are typically very easy to select for given applications, there are versions made for working with high amperage, high voltages and other electrical conditions where selecting the right cable may require that this be taken into account.

There are also many different mounting types for these cables, making them suitable for use in all different types of builds. Cables that are designed to be used in surface mount applications, PCP mounts, cable mounts, panel mounts, through hole and other type of mounting options are all widely available. Termination methods are also varied, ranging from simple solder terminations to crimping connections, cable connections, screw down connections, plug-in connections and more.

Because these are among the most reliable ways to make connections, IDC connectors are used under very demanding circumstances. In those cases, very rugged versions of these connectors can be purchased. Some of the designs are capable of operating at temperatures that range as high as 130°C and as low as -65°C. These types of components allow the convenience and reliability of insulation displacement connectors to be employed in applications much more demanding than a simple computer or telephone connection.

For industrial uses, common mounting options such as rack mount designs are available, allowing them to be used with very large-scale applications.


Other Considerations

Not all IDC connectors are particularly complex. There are, for instance, examples that only have one or two contacts in them. These are excellent solutions for running individual strands of wire that need to be reliably connected without having to deal with soldering or other types of connections.

The largest IDC connectors can have as many as 100 contacts in them, making them suitable for the most complex applications. For custom builds in industrial settings and development settings, there are generally IDC connectors available that can accommodate most any need.

The arrangement of the connectors is also a primary consideration. In some cases, all of the individual strands of the cable are laid out side-by-side. These wide connectors can provide a very flat profile, however, making them ideal for inclusion in some very space constrained builds.

Other connectors have the rows of connections stacked on top of one another, giving them a squarer or rectangular arrangement and making them the best options for other types of builds. The flexibility makes them very useful and versatile enough to suit most development needs.

These connectors are also available set up so that they connect to a socket at a specific angle. Straight and right angle options allow builders to properly place cable for concerns such as cooling, saving space and so forth. With the right angle, connections can be made in very tight spaces, making these ideal solutions for industrial settings where many single board computers or other electronic devices may be situated in a tight space, such as in an embedded system.

Because these devices make such reliable connections, they are also ideally suited for environments where dust and other hazards may pose significant threats to electronic equipment. In situations where such equipment needs to be repaired, these connectors can drastically reduce the amount of time required to make those repairs, often reducing repairs to a simple swapping out of cables.

IDC connectors have become common equipment because of their price advantages, as well. In addition to the amount of money they save in labour time, they also come at very inexpensive prices, making them easily replaceable and entirely suitable for use in prototyping and other endeavours that consume components. Data sheets for individual components will give detailed specifications, allowing the user to determine exactly which option will be the most appropriate for their desired application.