pcb制造缺陷解决方法（PCB manufacturing defect solutions）.docVIP

pcb制造缺陷解决方法（PCB manufacturing defect solutions） This paper contributed by jinshangxie. Doc document may at the WAP end of the browsing experience poor. Suggest you select TXT, or download the source file to the machine view. PCB solutions for manufacturing defects Involves more procedures in printed circuit board manufacturing process, each procedure has possible quality defects, these quality always involves many aspects, solve more trouble, because of the reasons of the problems are many, some of which are chemical, mechanical, optical plate, etc.. After decades of practice, combined with the corresponding data to solve the practical experience and quality is always related to solve technical problems, are summarized as follows: the manufacturing process defects, causes and solutions of process defects for 1 minutes film temperature and low pressure increases the temperature and pressure of pressure adjustment screw locking screw pressure due to the edge of the film the film tension is too large for printed circuit board, resulting in poor adhesion of the film coating film and the surface collapse bad solutions like the poor capacity of excessive exposure exposure reduced exposure time image of yin and Yang; sensitivity is too low and the film surface after adjusting the light intensity is insufficient contact overheating check the cooling system for intermittent exposure to continuous exposure to dry film storage conditions poor in yellow under the shade above developed area scum developer ingredients is too low The developer containing membranous excessive developing, cleaning the long time interval the developer injection pressure is insufficient over exposure correction improper exposure time sensitivity of maximum and minimum sensitivity ratio shall not be less than 3 underexposed, resulting in film polymerization is not sufficient to increase the exposure and drying time increase the exposure time and reduce the development of film color, bright surface shal