What Is Ribbon Cable?
Ribbon cables are flat, flexible cables that consist of multiple conducting wires running parallel to each other and held together by a thin strip of insulating material. They are widely used in electronic devices, computers, and other industries where space is at a premium, and a large number of conductors need to be bundled together in a compact package.
Ribbon cables were first introduced in the early 1950s as a way to connect early computers and mainframe systems. They quickly became popular due to their ability to transmit a large amount of data over a small space, making them ideal for use in electronic devices and other applications that require compact, high-speed data transmission.
Today, ribbon cables come in a variety of types, including flat, round, shielded, and twisted designs, each with its unique features and applications. They are used in a wide range of industries, including electronics, medical equipment, aerospace, defense, and robotics.
In this blog post, we will explore the different types of ribbon cables, their applications, advantages and disadvantages, assembly methods, connector types, and termination techniques, giving you a comprehensive understanding of this essential component in modern electronics.
Ribbon Cable Types
Flat Ribbon Cable
- Consist of of multiple parallel conductors (wires) that are laid flat and held together by a thin, flexible insulating material
- Typically used in applications where space is limited
- Available in various widths and lengths
- Suitable for high-speed data transfer and low-voltage power applications
- Can be customized to meet specific application requirements
Flat ribbon cable is the most commonly used ribbon cable, and it is available in various UL styles. Common styles are UL2651, UL2678, and UL2468. These styles have different specifications, including rated voltage, AWG size, and working temperature.
Round Ribbon Cable
- Consists of round conductors bundled together in a parallel configuration
- Provides better flexibility and durability compared to flat ribbon cables
- Suitable for applications where bending and twisting is required
- Used in applications such as robotics, automation, and medical equipment
A round ribbon cable is a ribbon cable that has a cylindrical shape due to its flexible, round outer jacket that covers the flat ribbon structure.
Shielded Ribbon Cable
- Consists of a flat or round ribbon cable with an added layer of shielding
- Provides protection against electromagnetic interference (EMI) and radio frequency interference (RFI)
- Typically used in applications such as aerospace, defense, and industrial automation
- Available in different types of shielding, including foil, braided, and combination of both
A shielded ribbon cable is a variant of the round ribbon cable, featuring an extra layer of shielding that protects the cable from electromagnetic interference (EMI).
Twisted Ribbon Cable
- Consists of twisted conductors in a parallel configuration
- Provides better crosstalk reduction and EMI protection compared to flat ribbon cables
- Suitable for high-speed data transfer applications
- Used in applications such as telecommunications and networking
Twisted ribbon cables, also known as twisted pair ribbon cables, are a type of ribbon cable that uses twisted pairs to reduce crosstalk and electromagnetic interference between wires. The most common twisted ribbon cable is AWG28, 1.27mm pitch.
Ribbon Cable Applications
The specific applications will depend on the requirements of the system in which they are being used. Following are some of the most common. Note that these are not the only applications for each type of ribbon cable:
Flat Ribbon Cables:
- Used in printers, scanners, and other office equipment
- Used in computers for connecting hard drives, CD/DVD drives, and other components
- Used in audio and video equipment for connecting components such as speakers, amplifiers, and displays
Round Ribbon Cables:
- Used in robotics and automation systems
- Used in medical equipment for connecting sensors and other components
- Used in industrial equipment for connecting motors and other devices
Twisted Ribbon Cables:
- Used in communication systems for transmitting signals over long distances
- Used in high-speed data transmission systems
- Used in networking equipment for connecting routers, switches, and other components
Shielded Ribbon Cables:
- Used in aerospace and military applications for their resistance to interference and noise
- Used in medical equipment for connecting sensitive sensors and other components
- Used in industrial equipment for connecting motors and other devices where electromagnetic interference (EMI) is a concern.
Advantages & Disadvantages of Ribbon Cable
Ribbon cables come in various types, such as flat, round, shielded, and twisted, each with its unique features and characteristics. While ribbon cables offer many benefits, they also have some drawbacks that must be considered when choosing the right type for your application.
Advantages:
- High Flexibility: Flat ribbon cables are highly flexible due to their multiple conductors in a flat configuration. Twisted ribbon cables are also highly flexible, making them suitable for applications that require frequent movements or changes in orientation.
- Space-Efficient: Flat ribbon cables and round ribbon cables are space-saving solutions, allowing them to be easily routed and placed in tight spaces, which is especially useful in electronics and computer applications.
- Cost-Effective: Ribbon cables, especially flat and round ones, are typically more cost-effective than other cable types, such as shielded cables. Their simple construction and flat design make them easy to manufacture in large quantities, which helps keep their cost low.
- Easy to Terminate and Assemble: Ribbon cables are generally easy to terminate and assemble, regardless of the type. IDC termination and crimping are common methods used for flat ribbon cables.
Disadvantages:
- Limited EMI Shielding: Shielded ribbon cables are the best option for applications that require EMI protection. Flat ribbon cables and twisted ribbon cables offer limited EMI shielding, which may not be sufficient for applications that require high EMI protection.
- Limited Strain Relief: All types of ribbon cables are susceptible to strain damage, especially at the points where they are connected to a device. Proper strain relief is required to prevent damage, which may not be possible in all applications.
- Susceptible to Noise Interference: All types of ribbon cables are susceptible to noise interference, which can cause data corruption or signal loss. Shielded ribbon cables offer the best protection against noise interference.
In conclusion, choosing the right type of ribbon cable for your application requires careful consideration of the advantages and disadvantages of each type. However, when used appropriately, ribbon cables can be a cost-effective and space-efficient solution for many applications.
What Is Ribbon Cable Assembly
Ribbon cable assembly is the process of attaching connectors to the ends of a ribbon cable in order to make it ready for use in a specific application. This process typically involves stripping and terminating the individual conductors of the ribbon cable, inserting them into the appropriate connectors, and securing them in place using crimping or soldering techniques.
Related post: Ribbon Cable Assembly Manufacturing: Manually VS Automatically
Ribbon cable assemblies are commonly used in electronics and computer applications where a high density of connections is required.
Ribbon Cable Connector Types
Ribbon Cable Termination Method
There are three ways to terminate ribbon cable:
IDC (Insulation Displacement Connector) Termination
IDC termination is a popular method for terminating ribbon cables. It uses a specialized connector that cuts through the insulation of the cable to make contact with the individual conductors. IDC termination is quick and easy, and does not require stripping the insulation from the cable.
Crimp Termination
Crimp termination typically involves using open barrel terminals that are crimped onto the individual conductors of the ribbon cable using a specialized crimping tool. The crimped terminals are then inserted into a connector housing to make a secure connection.
Soldering Termination
Soldering is a method for terminating ribbon cables that involves melting a metal alloy onto the individual conductors of the cable to make a permanent connection. This method is often used for cables with lower numbers of conductors or when a high degree of customization is required. Soldering provides a strong and reliable connection, but can be time-consuming and requires some skill to do correctly.
IDC Connectors:
Crimp Style Connectors:
Factors to Consider When Choosing a Termination Method
Application Requirements: The termination method should be chosen based on the specific requirements of the application. For example, the method should be able to handle the required signal or power transmission, and should be compatible with the connector and cable types used in the application.
Environmental Factors: Environmental factors such as temperature, humidity, vibration, and exposure to chemicals or other substances should be taken into account when selecting a termination method. The method should be able to withstand the environmental conditions present in the application without degrading over time.
Cost and Efficiency: The cost and efficiency of the termination method should be considered, as this can impact the overall cost and performance of the cable assembly. Some methods may require specialized tools or equipment, which can increase the cost of assembly.
Reliability and Durability: The termination method should be reliable and durable, and should be able to withstand repeated use and handling without degrading or failing. The method should also provide a secure and stable connection between the cable and connector, with minimal risk of disconnection or signal loss.
Other factors to consider may include ease of assembly, compatibility with other components in the system, and the ability to meet any regulatory or safety requirements that may be applicable.
Frequently Asked Questions
Is it OK to bend a ribbon cable?
Yes, it is generally okay to bend a ribbon cable, but it should be done carefully to avoid damaging the cable. Ribbon cables are designed to be flexible and to bend easily, but they do have their limitations. Excessive bending, twisting, or pulling can cause the cable to break or develop internal damage, which can impact the performance of the cable.
It is best to follow the manufacturer’s recommendations for the minimum bend radius for the specific cable. If you can’t find it, following this rule: Ribbon cables shall not be creased, folded or bent less than three insulated wire diameters (short-term). The recommended long-term bend radius is ten diameters.
Is flat cable the same as ribbon cable?
While flat cable and ribbon cable are often used interchangeably, there are some subtle differences between the two. Flat cables generally refer to any cable that has a flat and wide shape, while ribbon cables specifically refer to cables with multiple parallel conductors in a ribbon-like formation.
Can you twist ribbon cable?
No, twisting a ribbon cable can cause damage to the individual conductors and can increase crosstalk and electromagnetic interference. Ribbon cables are designed to be flat and should not be twisted.
It’s OK if there is a little twist during routing. You should NOT intentionally twist ribbon cable for any reason.
Can ribbon cables be repaired?
Yes, it is possible to repair a ribbon cable if it is damaged or broken. The specific repair method will depend on the type and location of the damage, but it typically involves cutting the cable to remove the damaged section and splicing in a new length of cable using crimping or soldering techniques.
Can you cut flat ribbon cable?
Yes, ribbon cables can be cut to length using a sharp blade or scissors. Whether you are using IDC termination or crimp termination, you will need to cut the ribbon cable to desired length.
However, care should be taken not to damage the individual conductors during the cutting process. It is also important to ensure that the cut is made straight across the cable to avoid any damage to the conductors.
Does it matter which way a ribbon cable goes?
Technically the orientation doesn’t matter if it functions. But when you are using a ribbon cable with a red strip, the red strip should be connected with PIN #1 of the connector.