基于激光选区的FR-4表面微带天线制备OA

With the development of wireless communication,microstrip antennas have been widely applied in various fields owing to their advantages such as small size,light weight,and low cost.To address the problems commonly existing in traditional antenna manufacturing processes,such as long production cycles,high costs,and easy peeling of coatings,laser surface treatment technology was employed to selectively roughen the FR-4 dielectric substrate,and then the metal layer was prepared through electroless plating.The surface morphology and roughness of the dielectric substrate before and after laser surface treatment were analyzed through Scanning Electron Microscopy(SEM),Scanning Probe Microscopy(SPM),and Laser Microscopy.By examining the microstructure of the dielectric substrate under different laser parameters and the critical load of the coating under different laser parameters,the effects of various laser parameters on the substrate were analyzed.Laser output power(A),treatment times(B),and scanning speed(C)were selected as the independent variables of the experiment,with the critical load(Lc)of the coating as the response value to optimize the laser parameter through a Box-Behnken experimental design.The results showed that after laser surface treatment,the RMS(Root Mean Square)of the substrate increased from 4.7 nm to 47.51 nm.With the increase of laser output power and treatment times,the surface roughness gradually increased,while both surface kurtosis(Sku)and surface skewness(Ssk)showed a trend of first increasing and then decreasing.The critical load also exhibited a trend of first increasing and then decreasing.This indicated that the critical load of the substrate did not increase with the increase of surface roughness.When the surface was predominantly peaked,the critical load of the coating was reduced.By using Design Expert software for design and calculation,a binary multiple regression equation was obtained:Lc=11.20-0.7750×A-1.83×B+1.51×C-0.3075×AB+0.5125×AC-0.2725×BC-3.67×A2-0.3838×B2-2.31×C2.The R² of this model was 0.958 1.By analyzing the F-values,it was found that the order of effect of the three factors(A:5.61,B:31.36,C:21.23)on the critical load of the coating was as follow:treatment times(B)>scanning speed(C)>output power(A).The optimized laser parameters were determined as follow:scanning power 9.997%,scanning times 1,and scanning speed 437.8 mm/s,with a predicted critical load of 12.99 N.A cross-cut test was performed on the experimental samples,and the adhesion of the coating reached ISO class 0.The minimum S11 parameter of the prepared antenna was-32.83 dB,which was less than-10 dB.To sum up,adhesion does not increase with roughness,but rather decreases due to stress concentration.The measured S11 curve of the prepared antenna is basically consistent with the simulated curve,including that the manufacturing process does not significantly affect the input impedance of the antenna,meeting the design requirements.This study has certain innovation and reference value for the preparation of microstrip antennas.