基于在机测量的曲面共形电路3D打印误差补偿方法

Error compensation method for 3D printing of curved conformalcircuits based on-machine measurement

基于3D打印技术制备曲面共形电路具有广阔的应用前景,然而,由于曲面基材加工误差和导电线路定位误差的影响,导致曲面电路3D打印头高度难以精确控制,进而影响打印精度。为此,本文以气动式直写打印为研究对象,提出了一种“在机测量+线路模型重构”的打印头高度误差补偿方法。设计了一种曲率自适应测量点选取方法,利用NURBS曲线反算法对测量数据进行重构,还原真实线路模型。通过生成真实线路的打印轨迹,替换原始理论打印轨迹,补偿了打印头高度误差。自主搭建了一套集成了在机测量系统的曲面共形电路3D打印平台,设计了直线、圆弧与NURBS自由曲线3种形状的线路,进行补偿前后电路打印的对比实验。结果表明,未进行补偿前,在线路曲率较大的地方,线路在基板上的波峰处会产生拉丝现象,波谷处会产生堆叠现象,而补偿后的导线线宽比较均匀;进一步对每条导线的电阻进行测量,发现各条线路补偿前的电阻值波动较大,补偿后的电路的电阻值均匀,且相较补偿前平均降低65.99%,最大电阻降幅达85.75%。

Surface conformal circuit based on the 3D printing technology has broad application prospects.However,due to the influence of machining errors in curved substrates and positioning errors in conductive circuits,it is difficult to accurately control the height of the 3D printing head for surface circuits,which affects printing accuracy.Therefore,this article takes pneumatic direct writing printing as the research object and proposes a print head height error compensation method of“on machine measurement+line model reconstruction”.A curvature adaptive measurement point selection method is designed,which uses the inverse NURBS curve algorithm to reconstruct the measurement data and restore the real line model.By generating the print trajectory of the real circuit and replacing the original theoretical print trajectory,the print head height error is compensated.A 3D printing platform for surface conformal circuits is established independently by integrating with an on-machine measurement system.A comparative experimental plan is also designed on circuit printing before and after compensation with three shapes of circuits:straight lines,arcs,and NURBS-free curves.The results show that before compensation,in areas with high line curvature,the wire drawing phenomenon occurs at the peak of the line on the substrate,and the stacking phenomenon occurs at the valley of the line.The wire width after compensation is relatively uniform.Further measuring the resistance of each wire shows that the resistance values of each line fluctuated significantly before compensation,and the resistance values of the compensated circuit are uniform,with an average decrease of about 65.99%compared to before compensation,and a maximum resistance decrease of 85.75%.