From cutting to molding! This article will show you the whole process of FPC production!

嘉立创FPC

From cutting to molding! This article will show you the whole process of FPC production! [Copy link]

With the industry development trend of electronic miniaturization, FPC soft boards, as important connection materials, have been widely used in computers, mobile phones, notebooks, IPADs, medical, automotive electronics, military and other products.

However, the FPC process is very complicated. To produce a high-quality flexible circuit board, there must be a complete and reasonable production process, and each process must be strictly implemented.

Next, we will unveil the mystery of FPC from its production process!

1. Cutting

Flexible materials are packaged in rolls and cut into required sizes according to MI dimensions.

2. Drilling

Perform CNC machining on the substrate to drill through holes or positioning holes to facilitate the conduction of copper materials on both sides after subsequent copper plating.

3. Black hole/electroplating

For boards that have just had holes drilled, the upper and lower copper layers are not conductive and need to pass through black holes to form a conductive layer, and then electrochemically plate hole copper on the conductive layer to achieve conductivity between the upper and lower copper layers.

4. Film pasting/exposure

A photosensitive film is pressed onto the electroplated board surface, and the circuit pattern is transferred to the photosensitive film by photolithography.

5. Development/etching/film stripping

Development: Develop the dry film without photolithography to expose the copper foil outside the circuit pattern Etching

: Use chemical solution to etch away the copper foil exposed after development De-filming

: Use sodium hydroxide to remove the dry film of the circuit pattern to expose the final circuit pattern

6. Covering film

In order to protect the circuit pattern and prevent short circuit and oxidation, an insulating layer must be made on the conductor. The insulating layer used in general flexible boards is called a cover film. The process involves opening a window on the cover film where the copper needs to be exposed at the pad position, and then sticking the cover film with the window opened on the etched board. The cover film is available in yellow, black, and white.

7. Immersion Gold

The surface treatment of FPC generally adopts the gold immersion process, which is to first immerse a layer of nickel on the exposed pad, and then immerse a thin gold layer of 1u" or 2u" to prevent the pad from oxidation and improve solderability.

8. Characters

The characters required by the customer are printed on the board by inkjet printing; the text ink is then hardened on the board by baking to prevent it from falling off.

9. Testing

The conductivity of the board is tested by a flying probe tester, mainly to detect whether the board has open or short circuits.

10. Subsidy

PI, electromagnetic shielding film, FR4, steel sheet, adhesive and other auxiliary materials are pasted on the board according to customer requirements.

11. Laser Forming

The laser energy is used to cut out the shape of the board, separate the unnecessary waste, and obtain the final shape of the board.

12. Inspection of packaging

We conduct comprehensive inspections on FPCs according to customer-specific requirements or IPC inspection standards, screening out problems such as poor appearance to meet customer quality standards.

From the introduction of each production process above, it is not difficult to see that the FPC production process is similar to that of ordinary hard boards, but the soft boards have added reinforcement processes. In addition, the FPC boards are relatively thin and more difficult to produce. However, due to the excellent flexibility, lightness and reliability of FPC, it provides a wider range of implementation space and new design solutions for equipment and products in many fields, and is increasingly favored by a large number of solution engineers.