Is it better to use a B TO B connector or a gold-finger plug for flexible display cables?

       Many customers encounter this issue when choosing a display: some flexible display cables use B2B connectors, while others use direct gold-finger plugs. They are unsure which to choose. Shenzhen Hongjia Technology Engineering provides a simple analysis here:

1. Connector Solution

This method requires a separate connector (usually a ZIF or LIF connector) soldered onto the motherboard. The flexible circuit board is directly inserted into this connector and secured with a locking lever.

· Advantages:

· High Reliability: The mechanical locking mechanism ensures a strong connection, effectively resisting vibration and impact, and providing stable contact resistance.

· Easy Assembly and Repair: Easy for operators to use, with a large alignment tolerance. If the screen or cable is damaged, the locking mechanism can be easily opened for replacement without damaging the motherboard.

· Interface Protection: The connector acts as a "sacrifice," with wear primarily occurring on the connector itself, while the solder pads on the motherboard are protected. Replacing the connector is far less expensive than repairing the motherboard.

• Disadvantages:

• Space Occupancy: The connector itself has a certain height, posing a challenge for designs aiming for extreme thinness and lightness.

• Higher Cost: Increases the material cost of the connector.

• Complex Structure: Requires space and height for the connector within the motherboard layout.

2. Direct Gold Finger Insertion Solution

This method directly inserts the gold fingers (exposed gold-plated pads) of the FPC cable into the corresponding springs or slots on the motherboard, relying on the pressure of external structures (such as metal shields, screws, or plastic frames) to maintain contact.

• Advantages:

• Extreme Thinness and Lightness: Eliminates the height of the connector, making it the preferred solution for achieving ultra-thin designs.

• Low Cost: Eliminates a connector, significantly reducing costs in mass production.

• Simple Structure: Simplifies the motherboard layout.

• Disadvantages:

• High Reliability Risk: Contact quality depends entirely on the uniformity and durability of the applied external pressure. After prolonged use, pressure may loosen, leading to poor contact. Vibration and drops can also easily affect the connection.

• Difficult to assemble: Alignment requires extreme precision, typically requiring automated equipment. Manual operation is difficult and prone to damaging the gold fingers due to misalignment.

• Almost impossible to repair: After a few insertions and removals, the gold fingers may wear down or become damaged. During repairs, directly pulling the cable can easily cause the gold fingers to detach or deform the motherboard contacts, resulting in permanent damage.

3. So how should we choose?

• Choose a connector if:

• The product has high reliability requirements and needs to withstand certain vibration and shock environments (e.g., automotive displays, industrial equipment).

• The product needs to be easy to manufacture and repair (e.g., ordinary laptops, monitors).

• Conventional consumer electronics products where internal space is not extremely limited.

• Choose a direct gold finger plug-in connector if:

• Thinness and lightness are the highest priorities, and some maintainability and ease of assembly are acceptable (e.g., internal connections in high-end ultra-thin laptops and tablets).

• Extremely cost-sensitive and requiring massive production volumes, high-precision automated equipment ensures high assembly yield.

• Designed as "disposable," requiring almost no disassembly after assembly (e.g., the screen cable connections inside many mobile phones).

     In today's consumer electronics industry, both technologies are widely used, often appearing in the same device. For example, in an ultra-thin laptop, the main connection between the motherboard and screen might use direct gold-finger connectors for the sake of thinness, while the connections between the motherboard and components like the touchpad and keyboard might use traditional connectors. If reliability and maintainability are more important than saving a fraction of a millimeter in thickness, then connectors are a more reliable and mature choice. If you are building an ultra-thin, cost-sensitive new product with a high-precision automated production line, you should carefully consider the direct gold-finger connector solution.