陶瓷基板表面金属层结合强度测试与失效分析

Bonding strength test and failure study of the direct plated copper layer on the ceramic substrate

为了评估电子器件封装质量与可靠性,需要准确测量直接镀铜陶瓷基板(DPC)表面金属层与陶瓷基片间的结合强度。采用拉伸法对DPC陶瓷基板表面金属层结合强度进行了测试,分析了测试后基板断裂面的微观形貌与基板横截面元素组成。结果显示:以金属层面积作为受力面积计算强度时,所得平均拉伸强度为12.13 MPa;测试中基板断裂位置均为金属层下方陶瓷内,断裂面形貌符合陶瓷脆性断裂特征;基板横截面微观形貌及EDS能谱分析表明,过渡层金属钛(Ti)向陶瓷侧和铜侧发生了扩散,提高了金属与陶瓷间结合强度,同时陶瓷内部存在孔洞缺陷,受到外界拉力时易产生裂纹而出现脆性断裂。研究结果表明,DPC陶瓷基板金属与陶瓷间结合强度较高,基板最薄弱部位为金属层下方的陶瓷。

In order to evaluate the packaging quality and reliability of electronic devices,it is necessary to accurately measure the bonding strength between the direct plated copper(DPC)layer and the ceramic substrate.The tensile method was used to test the bonding strength,and the micro-morphology and composition of the cross-section of the substrate were analyzed after the test.The results show that the average tensile strength is 12.13 MPa,and the fracture locates in the ceramics under the metal layer.Moreover,the surface morphology of the fracture conforms to the brittle fracture characteristics of the ceramic.The micro-morphology and the EDS analysis of the cross-section of the substrate show that the transition titanium(Ti)layer diffuses innto both the ceramic side and the copper side,which improves the bonding strength between the metal layer and the ceramic.In addition,the existence of the cavity in the ceramic is prone to the cracks and brittle fractures when external tension was applied on the ceramic substrate.It is shown that the bonding strength of the DPC ceramic substrate is high,and the weak part of the substrate is the ceramic under the metal layer.