Design And Realization Of Characteristic Impedance Boards Based On Genesis Software

Signal integrity in the transmission cannot be obtained unless the characteristic impedance for PCB(Printed Circuit Board) matches that for the electrical components. Compatibility for the characteristic impedance was solved both in design and manufacture of impedance PCB.According to the theory of PCB design,the analysis involoved in the factors on impedance control,including copper width and copper thickness of line,dielectric thickness and dielectric constant. Impedance calculation for impedance PCB could be in evidence after presenting general standard and key factors. Solutions for the compatibility of the characteristic impedance were summarized to provide a reliable theoretical basis for system design of impedance PCB.During CAD(Computer Aided Design) stage,the key points and processes for impedance PCB was discussed with Protel99 se software. The design of impedance PCB should be carried out according to designing processes while the design rules and conditions shold be handled. Experiences and tricks for designing impedance PCB were investigated by introducing engineering-oriented constraint rules in layout process. In this way,solution speed for layout problem could be accelerated,thereby contributing to efficient layouts and lines placement according to actual constraint conditions and experiences. Based on the analysis of circuit module,schematic circuit diagram and corresponding PCB design were both obtained.Based on Genesi2000 software,CAM(Computer Aided Manufacture) manufacturing processes for high-frequency PCB was designed while the procedures for photographic films and drilling were prepared to meet the requirement of client and accord with the process capability of the company. C Shell under Window 7 condition was used to develop the automated scripts for impedance in order to avoid the complexity of design with Genesis2000 for impedance PCB.Technologies for impedance PCB were investigated Based on Genesi2000 software. Bad PCB products were analyzed on problems of plating uniformity,artificial and equipmental factors,including substitute mode of fixtures and splints in VCP(Vertical Continuous Plating),big V-bar change,the size and shape changes of the plating titanium anode. DOE(Design of Experiments) were used to obtain uniformly etching with best manufacturing parameters as the acid tank speed of 2.2~3.1 m/min,acid concentration of 4.5~5.5,solution temperature of 45±5℃and jetting pressure of 0.1~0.2Mpa.Aftering optimizing process and controlling procedure,impedance PCB could be well manufactured by passing the impedance test.