Guangzhou FPC board material expansion and contraction control methods which

Flexible Printed Circuit Board (FPC) refers to the Flexible Printed Circuit board (FPC), also known as the Flexible Printed Circuit board, Flexible Printed Circuit board, or soft board.  This FPC board has the advantages of high wiring density, light weight and thin thickness.  Widely used in mobile phones.  Laptop.  PDA. Digital camera.  LCM and many other products.  In recent years, WITH the rapid development of PCB manufacturing technology, the industry has put forward higher requirements for FPC board. Precision PITCH is the main breakthrough direction of FPC board in the future.  The stability of size and delicacy also lead to the rise of the cost of FPC board. How to control the contradiction between the two is the main breakthrough of FPC board material expansion and contraction control in the production process.  Here's how to control it.  The main points of control are briefly explained to you.  

First, design  

1. Circuit: Because the FPC board will expand due to temperature and pressure during the crimping, the expansion rate of the crimping finger should be considered in the initial design of the circuit and pre-compensation processing should be carried out;  

2. Layout: FPC boards of design products are distributed symmetrically throughout the layout as much as possible, and the minimum interval between each two P-CS products should be more than 2 MM. The copper-free part and the heavily perforated part should be staggered as far as possible.  

3. Material selection: the glue covering the film can not be too thin than the thickness of copper foil, so as not to cause deformation of the product when the glue filling is insufficient, the thickness of the glue and whether the uniform distribution, is the culprit of FPC board material shrinkage.  

4. Process design side: the covering film of FPC board should cover all copper foil parts as far as possible, and it is not recommended to stick the covering film to avoid uneven force when pressing. The PI reinforcing bonding surface glue on 5MIL should not be too large, if it cannot be avoided, the covering film should be pressed and baked before PI reinforcing bonding.  

Two, material storage  

I believe that the importance of material storage need not say more, it is necessary to store in strict accordance with the conditions provided by the material supplier, the cold storage of the cold storage, not careless.  

Three, manufacturing  

1. Drilling: FPC board drilling before the best baking, reduce the substrate due to the high moisture content of the subsequent processing of the substrate expansion and contraction.  

2. Electroplating: FPC board should be made of short side splint, which can reduce the deformation caused by the water stress caused by the swing. When electroplating, the swing kinetic energy reduces the impact on the plate, so as not to cause adverse effects on the plate electroplating.  

3. Pressing: FPC plate traditional press machine is smaller than the fast press up, the traditional press is constant temperature curing, fast press is hot curing, so the change of the control glue of the transmission press to stabilize this, of course, the lamination of the plate is also a very important part.  

4. Baking: FPC board for fast pressure products, baking is often important part of the baking conditions must be reached to make the glue completely solidified, otherwise in the subsequent production or use after infinite;  The baking temperature curve is first gradually rising to the temperature at which the glue is completely melted, and then continuing at this temperature until the glue is completely solidified, and then gradually decreasing the temperature and cooling.  

5. During the production process, try to maintain the stability of temperature and humidity in all stations. Special attention should be paid to the storage conditions of the products when transferring between stations, especially when the products need to be sent out.  

4. Packaging  

Of course, the completion of FPC board products is not to say that all is well, to ensure that customers do not have any problems in the subsequent use, in packaging, it is best to bake first, the product in the manufacturing process of the base material absorbed by the moisture drying, and then the use of empty packaging, and guide customers how to save.  

Therefore, to ensure the stable quality of FPC board products, material preservation, process control, packaging and customer use must be strictly in accordance with the specific requirements.