Connectors in Electronics

Author: Liam Hayes (and one other contributor)

Following up from iFixit's current connector overview "Recognizing & Disconnecting Cable Connectors", a full connector categorisation structure seemed like a logical next step.

Beginning with a general overview, and then looking at each category to understand the differences and ways of operating them, this wiki should give some useful insights for anyone uncertain about the operation of connectors in repair.

This basic overview shows how we've categorised the connectors in this list.

FPCs (Flexible Printed Circuits) or FFCs (Flexible Flat Cables) are a very common type of cable used to connect components together within electronics. Often referred to as ribbon cables, these flat cables are malleable and very low profile, making them suitable for compact mobile devices and specialist hardware alike.

The connectors which link an FPC or FFC to a PCB (Printed Circuit Board) can vary widely by application, and the types each have different benefits, drawbacks, and methods of operation.

ZIF (Zero-Insertion-Force) connectors may be the most common, and most varied of the connectors in this list. They are easy to insert, and often have a locking mechanism which holds the FPC/FFC in place. The retention method is important to identify before operating a ZIF, as mistaking one for another can cause damage to these small and fragile connectors.

This type of ZIF connector has a small lever pointing in the direction of the FPC/FFC. The ZIF can be inserted while the lever is in the upright position, and is locked in place when the lever is 'flat', in parallel to the PCB. A spudger or a fingernail can be used to open this lever and unlock the connector, after which the FPC can easily be pulled horizontally out of the housing.
Shown: Recognizing & Disconnecting Cable Connectors

Back-flip connectors operate very similary to front-flip, however their locking lever is reversed, facing away from the insertion side of the FPC. Both are very common, and oberservation and careful trial and error may be needed to distinguish which one you are dealing with.

Shown: Kobo Clara Colour (N367B) Motherboard Replacement

A less common, but still considerable retention method uses barbed teeth inside the connector that allows for latch-free insertion, but for which pushing a release button or bar is necessary.

It is important not to pull an FPC out of a connector until you are sure that there is no retention method that you've missed.

Shown: PlayStation 5 LED Board Replacement

An even rarer version of this is a pinch-style locking mechanism, where the barbed teeth are released by squeezing the connector together to unlock the FPC.

Shown: Xbox Series X Motherboard Replacement

Some ZIF connectors use a locking latch which flaps down over the connector for a rigid and secure mount once the FPC is inserted. These can be tricky to flip up, but using a pick or spudger under the bar that wraps around the outside seems to be the most effective method.

The example shows a wire bundle instead of an FPC, but the same procedure applies.

Shown: IPEX Cabline CA

Similar to the Locking-Bar, but with a full cover over the top for increased rigidity and dust ingress prevention, the locking cage functions very similarly.

The example shows a wire bundle instead of an FPC, but the same procedure applies.

Shown: IPEX Cablin CA II

Slide-locks use a sliding (often plastic) latch to hold the FPC in place. They often have arrows indicating which direction to slide the latch, and once this has been done, the FPC should pull free with ease. These often have a plastic pull tab to assist with FPC removal.

Shown: Steam Deck Audio Board Replacement

Some ZIF connectors do not have any notable locking method other than a tight friction fit, and these can be inserted and removed with only the application of minimal force. They often have a plastic tab close to the end of the FPC to accomodate the user to pull the connector directly out, however this is not the only type of ZIF connector which can have this feature, so it is important to always identify what sort of connector is being used before assuming that it is non-locking.

Shown: PlayStation 5 LED Board Replacement

There are various other ZIF connector retention styles, many of which are proprietary or uncommon. If you can, find instructions that match the device, and otherwise proceed with caution.

Press-fit connectors are among the most popular connectors in mobile devices, and with good reason: they are low-profile, high-density, and easy to operate. To remove a press-connector simply get underneatgh the flat top with a spudger or fingernail, and pry it upwards gently. To reinstall, align the pins and press down slightly until there is a tactile click.

Many sizes exist of these, with small ones being used for peripheral connections such as fingerprint sensors, batteries and speakers. Larger ones are often used for display connections, cameras, and mother-daughterboard interconnects.

Shown: Samsung Galaxy S23 Plus Motherboard Replacement

Mezzanine types are fundamental connectors as they link primary functions such as power and data within sub-assemblies of devices. They come in many forms, with many leveraging the above ZIF connectors in compact consumer electronics. In specialised applications, there are other unique mezzanine connectors suited to specific use-cases.

High-speed data-focussed mezzanine connectors often use a lot of pins in an array, and may also use alignment pillars and locking mechanisms. They focus on signal strength and integrity, and it's important to be careful around the (often fragile) pins that they use.

Shown: Mac Pro Late 2013 Graphics Card Replacement / Molex HD Mezz Connector

Specialised high-power mezzanine interfaces often use thick-gauge wire and large contact pads to sustain high currents. They often use alignment pins and a strong locking function such as tabs, latches or even screws in some cases.

Shown: Mac Pro 2009-2012 Teardown / Molex EXTreme Guardian Connector

Edge connectors are unique due to their integration as physical parts of the PCBs that they are connecting. These use conductive pads in combination with sprung compression interfaces to ensure reliable contact. This is what many of the aforementioned high-power mezzanine connectors use as well, as they need maximum contact for high currents.

Not all use-cases are so specialised however, and the following spring connectors are used in some of the most common interfaces in electronics.

Spring fingers are essentially just springs that act as contacts between conductive pads on the docking PCB, and connect to traces on the receiving PCB, allowing for electrical connection without using a cable.

Examples within electronics include expandable memory, storage and networking using the M.2 standard, DIMM and CAMM2 standards as well as the PCIe expansion interface. Additionally, many IO (input/output) ports also use this technology, including USB and HDMI. Power plugs in most regions also rely on a scaled-up version of spring fingers to ensure a friction-fit and good electrical contact.

Shown: Memory in Lenovo ThinkPad T14 Gen 7 LPCAMM2 Memory Replacement / USB Port in Lenovo ThinkPad T14 Gen 7 USB-C Port Replacement

Pogo pins are generally larger than spring fingers, and are suitable for external use in consumer electronics. They are often known for their use as the interface for removable batteries in older phones, but are vital to modern wearables as well. The example of a pogo-pin-based charging interface for wireless earbuds is given.

This sort of connector is ideal for expansion or no-fuss contact charging in low-power applications. Users generally are not fully aware that they are operating an electronic connector, and repairs on devices that apply these connectors are simple (unless the compression connector itself is broken).

Shown: Pogo-Pin charging Interface on the Nothing Ear (1) Teardown

Zebra connectors are also a type of compression connector, as they sit in between two sets of conductive pads. They are unique because they are striped, alternating between traces, allowing for higher bandwidth than with traditional compression connectors. This allows them to send basic data, not only power, making them capable of sending signals to LCD displays mounted on PCBs amongst other, more specialised applications.

Shown: LCD Zebra Connector

One of the most common yet most fiddly connectors on this list are snap-on coaxial connectors. These are tiny and can be difficult to align, especially in tight spaces within compact consumer electronics, which is where they are often used.

To uninstall a micro-coax connector, lever the head up gently from below with precision tweezers or a spudger, similarly to a press-connector.

Reinstallation is more tricky, and precise alignment is vital. One common approach is to hold the round plug head with a set of precision tweezers, and once it is aligned over the socket pin, press down with a spudger or fingernail.

Shown: Samsung Galaxy S20 FE 5G USB-C Port and Charging Board Replacement