I. What is an FPC connector?

The FPC connector, as the name suggests, is a special connector used for connecting Flexible Printed circuits (FPC).

1.FPC: It is a printed circuit board made of flexible polyimide (PI) or polyester (PET) film, featuring light weight, thin thickness, flexibility and foldability.

2.FFC: Often mentioned together with FPC is FFC (Flexible Flat Cable), which is a standardized prefabricated ribbon cable. It usually has no lines at both ends and requires connectors for conduction.

Therefore, FPC connectors are usually also compatible for connecting FFC cables, so they are often collectively referred to as FPC/FFC connectors. Core function: Inside the device, it provides reliable and repeatedly pluggable electrical connections and signal transmission between two PCB boards or between a PCB board and modules such as display screens/cameras.

Ii. Main Structure and Components

A typical FPC connector is mainly composed of the following parts:

1. Insulator/Housing: Usually made of plastic (such as PBT, LCP), it is used to fix terminals and provide structural support. LCP material has better high-temperature resistance and is suitable for SMT reflow soldering process.

2. Contacts/Terminals: Metal parts (usually phosphor bronze), which are the core of the connector, are responsible for conducting electricity by contacting the gold fingers (conductive wires) on the FPC/FFC. The design and elasticity of terminals are of vital importance, determining the pressure and stability of the connection.

3. Actuator/Latch: This is the most distinctive part of the FPC connector. The FPC can be locked and released by opening and closing this cover. It can provide uniform locking force to ensure reliable contact.

Flip Lock Type: Like a flip cover, open it, insert the FPC, and then lock it down.

Lift-Lift Type: The lid needs to be lifted first, the FPC inserted, and then the lid pressed down.

4. Pin/terminal tail (Solder Tails) : the part at the bottom of the connector that is soldered to the PCB board. It usually has two types: surface mount technology (SMT) and through-hole through-hole (DIP). In modern equipment, SMT is the main type.

Iii. Main Types and Classifications

FPC connectors can be classified in different ways:

By locking method:

Flip Lock

Lift-Lift type

* Sliding Insertion Force (ZIF-Zero Insertion Force) : There is almost no resistance during insertion, and it is locked by sliding the lock. It is often used in more precise applications.

Non-zero insertion and extraction force (Non-ZIF) : A certain force is required during insertion, which is less common nowadays.

By pin Pitch: This is one of the most important selection parameters, referring to the distance between the centerlines of two adjacent terminals. The smaller the spacing, the more precise the connector.

1.00mm, 0.80mm, 0.50mm (more common)

0.30mm, 0.25mm, 0.20mm, 0.15mm (for ultra-high density connections, such as mobile phone cameras and displays)

By row count:

Single-row: The most common.

Double-row: It is used in situations with a very large number of pins and can save space.

By installation method:

Surface mount Technology (SMT) : The mainstream method, suitable for automated production.

Through-hole insertion (DIP) : It has higher welding strength, but lower production efficiency.

By height:

"Standard type"

* Low Profile: Used for devices with limited space height.

Iv. Main Application Fields

FPC connectors are widely used in various thin, light, short and small electronic devices due to their compact and flexible features

Smartphones/tablets: The internal display screens, touch screens, main and secondary boards, camera modules, side buttons, fingerprint recognition modules, etc. are almost all connected using FPC connectors.

Laptop: Connect the motherboard to the display (screen ribbon cable), touchpad, keyboard, camera, etc.

Digital camera/camcorder: Connect the mainboard to the sensor, display screen, and lens module.

Liquid crystal display devices: The connection between the driver board inside televisions and monitors and the liquid crystal panel.

Automotive electronics: central control screens, sensors, instrument panels, etc.

Medical equipment, drones, wearable devices (such as smartwatches/bracelets), etc.

V. Key Points for Selection

When choosing a suitable FPC connector in the design, the following factors need to be considered:

1. Pitch: Determined based on the line width and line spacing of FPC/FFC.

2. Number of Positions/Pins: How many signal lines are required.

3. Installation method: SMT or DIP.

4. Mating Height: The vertical space reserved inside the device for the connector.

5. Locking method: Choose between flip cover or lift cover based on the operating space and ease of use.

6. Electrical performance: Rated current, voltage, contact resistance, insulation resistance, etc.

7. Mechanical durability: Insertion and extraction life (usually required to be more than 20 to 50 times).

FPC connectors are the "Bridges" for achieving internal modular connections in modern electronic products. They are characterized by small size, high density and high reliability. Understanding its basic structure, types and key points for selection is of vital importance to the design, production and maintenance of electronic products.