PCB ribbon connector is typical in applications requiring space efficiency, durability, and reliability advantages when handling circuit board connections.
They achieve these advantages using features like multiple pins and latching clips for strain relief.
Let’s analyze this cable-to-board connector to understand its types and advantages/reasons why you should include the joint in your project.
What Is a Ribbon Cable?
Also known as a flat or multi-wire planar cable, a ribbon cable is a flat wire bundle containing multiple insulated conductors running parallel from source to destination. These wires must have the following characteristics.
- Parallel configuration: The individual wires must have this configuration either with different colors for color-coding or single colors.
- Insulating material: Each wire in the parallel assembly should have an insulating material separating it from the adjacent ones.
A ribbon cable before termination
- Flexibility: Ribbon cables are as flexible as flex PCBs and more flexible than round cable types. Therefore, they are ideal for connecting circuit boards or electrical components to PCBs in a limited-space installation.
- Pitch: A ribbon cable’s pitch is the distance between the mid or centerlines of adjacent copper conductors.
- Termination: Ribbon cables must have terminations or connectors to link them to the PCBs. This article focuses on these terminations, which come in different types.
What Are PCB Ribbon Connectors?
These ribbon connectors are PCB terminations specifically designed to connect to ribbon cables. While the connectors are available in different types, they all have the following features or properties.
A ribbon cable connector
- Contact arrangement: These ribbon connectors must have a pin arrangement that aligns with the copper wires in the flat cable to make the connection reliable and secure.
- Pitch matching: Similarly, the connector pitch must match the wire spacing to create secure, aligned connections.
- Row arrangement: These connectors usually contain multiple pin/socket rows to conduct the electric or data signals to and from the circuit board. The more rows, the more wires the connectors can accommodate for signal transmission.
- Termination technology: These connectors can feature different terminating technologies or types, which we’ll look at later in the article.
- Mounting options: Since they are PCB components, ribbon connectors can have a surface or through-hole mounting technology.
- Locking mechanism: Locks might be necessary to secure the electrical link between the cable and the circuit board to prevent accidental separation when exposed to vibrations.
A macro ribbon cable
Types of PCB Ribbon Connectors
IDC (Insulation Displacement Connector)
Also known as insulation-piercing contact connectors, IDCs contain sharp blades that cut through the ribbon cable insulation to contact the copper conductors. This design eliminates the need to strip the ribbon cable insulation to join the two.
IDC ribbon cable connectors
If well done, this electrical joint forms a cold weld that is as reliable as an airtight connection.
These connectors are compatible with ATA cables and are typical in consumer electronics like computers and telecommunication equipment.
These connectors get their name from their D-shaped metal shield that surrounds a row of two or more parallel pin or socket rows. The metal shield mechanically supports the rows of pins or sockets to ensure they retain the correct orientation.
A D-sub connector (note the D-shaped metal shield around the pins)
D-sub connectors are suitable for parallel and serial ports, such as linking printers in computer/telecommunication applications.
This connector has become the international standard form of EN and IEC 60603-2 and is typical in rack-based electrical systems.
Mechanically, this connector can have one, two, or three rows of pins or sockets with 16 or 32 columns.
A ribbon cable connector
NuBus and VMEbus systems use DIN 41612 connectors widely, but you can also find them in Pancon, Futurebus, and Europe Card buses.
PCB Transition Headers
These transition headers provide a quick, permanent flat cable termination for PCB-to-PCB, dual-in-line, wire-to-board, and separate header/socket connections.
The headers feature two rows of pins with the same spacing as IDC connectors and low contact resistance.
Micro Ribbon Connector
Also known as telco, mini D ribbon, 25-pair, or Amphenol connectors, micro ribbon connectors resemble their D-sub counterparts shape-wise. And they feature two parallel rows of contacts in the shielded case, as well.
But instead of having pins, these connectors feature small, tiny metal bands (ribbon contacts). Ribbon cable attachment to this connector is usually via crimping, soldering, or insulation displacement.
A 6-pin ribbon connector
Some of its applications include the 14-pin printer port, 20-pin VESA digital flat panel, SCSI connector, and RJ21X telco connector.
These headers feature the same spacing as standard DIL integrated circuits and connect two printed circuit boards using the appropriate DIL male-female connector. The devices are ideal for linking an IC to a circuit outside the host PCB.
Advantages of PCB Ribbon Connectors
- Space efficiency: The flat, parallel wire conductor arrangement enables more efficient use of space on the PCB surface.
- Mass termination: IDC connectors terminate multiple cables concurrently, streamlining assembly and electrical/data signal connections.
PCB ribbon cable connectors
- High-speed data transmission: If properly designed and shielded, ribbon cable terminations can transmit data at high speeds using these multiple wires.
- Simplified installation: IDC connectors simplify installation by allowing ribbon cable connections without stripping or crimping the wires.
- Cost-effective solution: Terminating multiple cables in one area streamlines the PCB manufacturing process, especially during high-volume production. This streamlining can cut manufacturing costs.
PCB ribbon connectors usually help interlink board-to-board, such as hard drive to motherboard in computers or server-to-server. However, their board applications can vary greatly depending on the type.