FPC board, also known as flexible circuit board, flexible circuit board, flexible circuit board, flexible circuit board, and flexible board, is a special type of PCB board. FPC board has the characteristics of light weight, thin thickness, soft and flexible. Compared with hard circuit board, flexible circuit board soft board has many advantages that hard printed circuit board does not have. For example, free bending, winding and folding can be arranged arbitrarily according to the requirements of spatial layout, and can be moved and expanded freely in three-dimensional space, so as to achieve the integration of element, component assembly and wire connection. The use of flexible circuit boards can greatly reduce the volume of electronic products, which is suitable for the development of electronic products in the direction of high density, miniaturization and high reliability. Therefore, FPCB has been widely used in aerospace, military, mobile communications, portable computers, computer peripherals, PDAs, digital cameras and other fields or products.
With the continuous development of the intelligence of the electronic industry, PCB and FPC are becoming smaller and thinner, more and more electronic components are contained, and the requirements for processing precision are also becoming higher and higher. At the same time, the application of laser in PCB and flexible circuit board is more and more extensive!
Application of laser in PCB and FPC manufacturing
PCB and FPC are one of the important components of the electronic industry, accounting for the largest proportion of all electronic component segments. With the increasing demand for wearable electronic consumer goods such as smart phones, the rapid development of PCB and FPC industries has been further promoted. The emergence of laser technology in the industry has led to explosive growth in PCB and FPC industries. The application of laser technology in PCB industry mainly includes the following aspects: laser cutting, laser welding, laser marking, laser drilling, etc.
Laser cutting in FPC
1. Ordinary FPC cutting
Active circuit board cutting (Routing) and traditional mechanical board splitting methods (such as die punching) will lead to large cutting width and excessive stress for disordered flexible circuits. The CO2 laser cutting method is also unsatisfactory in this respect, because it will produce a larger heat-affected area.
2. UV laser FPC cutting
The use of ultraviolet laser cutting can not only eliminate the physical stress of mechanical process, but also produce less thermal effect than CO2 laser cutting. The common ultraviolet wavelength is 355 nm, and its photon energy is just greater than the main bond energy C-C bond and C-N bond of the polymer material. It will not generate too much heat while breaking the chemical bond, so the cutting effect is far better than that of the long-wavelength laser.
This makes it possible for the processing of organic materials and the precision processing of various kinds of ceramics, which are widely used in SIP chip plastic packaging external cutting, circuit board splitting, soft board drilling, ceramics and LTCC drilling and segmentation, etc.