As a very important process in the rear section of FPC soft board, the stamping process is still important and the mold is even more important. Because the unreasonable situation of mold design and manufacture often occurs, which affects the quality, progress and delivery time, what problems should we pay attention to in mold design? Let's talk about it in detail in the following section.

Precautions for soft plate mold design

1. Selection of die steel

At present, there are many kinds of steel in the market, domestic and imported. As the FPC flexible circuit board mold, it must be high-quality special steel for mold, which requires high hardness, good hardenability and low wire cutting stress.

2. Manufacturing process of mold factory

Due to the high requirements for shape accuracy and position accuracy of the soft plate, the high requirements for the processing technology of the mold itself are generally required to carry out wire cutting slowly. The quality of wire cutting is one of the important factors that affect the use effect of the mold, which is closely related to the level of the machine and the technical level of the workers, while the assembly process of the mold is the key point in the later stage of the process. At the same time, it should also be considered that the difference between the male mold and the female mold during heat treatment is 8-10 degrees, which is convenient for mold repair.

3. Mold structure design

The die structure design is relatively simple in the metal stamping die, which is divided into blanking type and surface type. For blanking film, thermosetting adhesive film, electroplating line, PI and FR4 and other reinforcing plates, blanking type is used, because these materials are not easy to deform, and the efficiency is also high; In order to ensure that the shape does not deform, in addition to the fact that it is often organically formed, the surface shape is adopted; In addition, due to the deformation caused by blanking, the stainless steel reinforcing plates are all surface-shaped.

4. The number of mold holes

In order to reach the production capacity, the more efficient acupoints are, of course, the better. However, due to the impact of the size of the punch platform and the stability of the mold, and the impact of the stability of the FPC flexible circuit board substrate itself, the number of typesetting caused by the product shape, and also taking into account the reasonable cost and structure of the mold. For products with high tolerance requirements, generally speaking, FPC flexible circuit board mold one out of one, one out of two is more common.

5. Layout of mold positioning PIN

The function of locating PIN is to locate the products to be flushed. The stamping die requires balanced stress, and the FPC FPC mold is no exception. The mold shape should be opened in the middle of the mold as far as possible, so the location of the PIN should also be distributed around the product as far as possible. But at the same time, it is also necessary to take into account the requirements of the product itself, such as the places where the finger and center distance tolerance requirements are particularly strict, and the positioning PIN should be as close as possible.

6. Mold pre-expansion and pre-shrinkage

For places with high product tolerance requirements, especially the golden finger, if it is required to be within/-0.05MM, because it is difficult for the mold to reach this tolerance, it is necessary to make technical treatment for the mold, and considering that the mold will wear after a certain degree of use, the mold finger part is subject to unilateral pre-shrinking of 0.02, requiring the mold processing plant to pre-shrink 2 pieces during processing. After technical treatment, the defect rate of only the fingers is only about 1%, If there is no technical treatment, there are more than 10% defects.