基于A-Scan和C-Scan的多层陶瓷结构介质缺陷无损检测

Nondestructive testing of MCS dielectric defect based on A-Scan and C-Scan of Ultrasonic Test

摘要:

针对多层陶瓷结构(MCS)介质缺陷的超声检测(UT)技术开展了研究。首先，以多层瓷介电容器(MLCC)结构为例，通过薄层反射理论计算并证明了UT对空洞和分层等介质缺陷检测的适用性和有效性，即较低的频率对极薄的空隙也有很强的反射信号；同时，给出了C-Scan检测参数建议，包括等效焦距、表面波时间、门限和增益。其次，对MCS进行了实际的UT检测验证，表明50 MHz是最佳的筛选频率。最后，给出了A-Scan判别缺陷的理论依据和渡越时间定位缺陷纵深定位的方法，并通过制样检测进行了验证。

Abstract:

Ultrasonic Test(UT) technology for dielectric defects of Multilayer Ceramic Structure(MCS) is studied. Firstly, UT is proved to be applicable and effective to voids and delamination through thin layer reflections theoretical calculating on Multi-Layer Ceramic Capacitors(MLCC) structure, as low UT frequency can get very strong reflection signal at extremely thin aperture. Simultaneously, suggestion of C-Scan testing parameters including equivalent focal length, surface wave time, data gate and gain is given. Then, the practical UT test of MCS indicates that 50 MHz is the optimum screening frequency. Finally, defect determining and locating is accomplished via A-Scan and transit time respectively, the conclusion is also verified by sectioned UT sample preparation and detection.