In FPC production, molding is the process before quality inspection and packaging, and it is also the last step in the production process. The shape of FPC varies, either square, circular, elongated, conical, regular, or irregular. In order to ensure that the appearance of each product is unified, beautiful, standardized, and meets the design requirements, the FPC molding method generally chooses die punching molding, cutting molding, and manual molding. Choose different molding methods based on the quantity, accuracy, and delivery time required by customers.

Firstly, let's introduce die stamping forming. The main body of die stamping forming is the mold, and different FPC products require different molds.

The molds are divided by material, including steel molds and knife molds. Steel molds are made of steel with high accuracy, multiple stamping times, and are not easily deformed. They are the most commonly used molds, but due to their heavy weight, they often need to be moved during installation, and the cost is relatively high. Therefore, steel molds are generally not made too large and are suitable for FPC punching with single board sizes within 600mm; The knife mold is light in weight and low in cost, made of wood and steel blades with low accuracy. It is generally only suitable for products and auxiliary materials that do not have strict requirements for appearance accuracy, such as reinforcing pads (the knife mold will not be discussed in the future, and the mentioned molds all refer to hardware steel molds).

According to accuracy, there are three production methods for molds: precision mold, ordinary mold, and simple mold. These involve slow wire, medium wire, and fast wire; The mold made by slowly walking wire is a precision mold with an accuracy tolerance of ± 0.05mm. The steel is of good quality and not easily deformed, but it is expensive and takes a long time to make. Unless customers have special requirements for external shape accuracy of ± 0.05mm, this type of mold is generally not selected; The mold made by wire cutting is a regular mold with an accuracy tolerance of ± 0.10mm, which can meet most needs. The price is moderate, and the performance is stable. It is the type of mold that is commonly chosen; The mold made by fast threading is a simple mold with an accuracy of ± 0.2mm, which is slightly cheaper than ordinary molds. Generally, this mold opening method is only chosen for products with low requirements for appearance tolerance;

The steel mold is composed of an upper mold and a lower mold, with the lower mold as the base and the upper mold as the punching and cutting mold. After installing the mold onto the punching machine, it is necessary to adjust the stamping height of the mold using a test plate to select the most suitable stamping force, ensuring that the FPC can be cut according to the external design drawing without damaging other parts of the FPC that do not require punching. According to the size of the FPC, the mold often adopts a one out multiple method, that is, stamping once to form multiple pieces of FPC, thereby improving production efficiency. During the production process, without changing the FPC appearance design, the mold only needs to be made once and can be reused later, making it suitable for mass production and reducing unit production costs.

Secondly, it is cutting and forming, which is generally only used for samples and very small batch production. Cutting forming includes CNC knife cutting forming and laser forming. CNC cutting, input the cutting diagram into the computer, fix the FPC assembly on the device according to the positioning hole, and move the cutting head on the device according to the drawing line to cut the FPC into the specified shape. This cutting method, due to the small volume of the blade itself and the easy damage of the blade head, results in poor accuracy of the processed FPC, long processing time, and improper adjustment of depth, which can lead to excessive burrs and incomplete cutting. Before the emergence of laser cutting machines, it was generally only used for cutting and forming FPC samples, protective films, and electromagnetic films. With the popularization of laser cutting machines, due to their high accuracy (≤ 0.05mm), smooth and square cutting surfaces, fewer burrs, and faster speed than cutting, they have replaced the CNC cutting method. Currently, the vast majority of FPC samples are produced using this method. It should be noted that laser cutting uses high-energy red/ultraviolet wire harnesses for processing, so there may be burning marks on the cutting surface. To avoid affecting the appearance after production, it is best to use a dust-free cloth and alcohol to wipe.