微电路模块板级磁芯组装失效机理与工艺设计

Assembly failure mechanism and process design for board-level magnetic cores in microcircuit module

板级磁芯是国防军工及航空航天领域使用的微电路模块的重要组成部分,其组装的可靠性对产品性能起着至关重要的作用。为从根源上解决板级磁芯粘接的可靠性问题,文中通过分析板级磁芯粘接失效机理,创新性地引入可靠的磁芯粘接胶和新的灌封工艺设计,对磁芯粘接胶和灌封工艺进行针对性的探索;并采用含玻珠的新磁芯粘接胶对板级磁芯进行粘接,淘汰真空浸入式灌封而采用新的旋转灌封工艺,形成高可靠的板级磁芯组装工艺技术,彻底地解决板级磁芯粘接面开裂的问题。研究得出:板级磁芯组装失效的根源是磁芯粘接力不足以抵抗环境试验和产品内部的灌封胶应力,采用新型板级磁芯粘接胶、改进灌封方式和磁芯填充工艺是避免板级磁芯组装失效的有效工艺途径。

The board-level magnetic cores are an important part of the micro-circuit modules used in the fields of national defense industry and aerospace. Their assembly reliability has an extremely important impact on product performance. In order to solve the bonding reliability problem of board-level magnetic cores from the root,the reliable core bonding adhesive and new potting process design are introduced innovatively by analyzing the bonding failure mechanism of board-level magnetic cores to explore the bonding adhesive and potting process of the magnetic core in a targeted way. The new magnetic core adhesive containing glass beads is used to bond the board-level magnetic core. The vacuum immersion potting is eliminated,and the new rotary potting process is adopted to form a highly reliable assembly process for board-level magnetic core,which can thoroughly solve the problem of the bonding surface cracking of the board-level magnetic core. The research results show that the root cause of the assembly failure of the board-level magnetic core is that the bonding force of adhesive for the magnetic core is insufficient to resist the environmental test and the stress of the potting glue inside the product. Application of the new type of board level magnetic core adhesive,improved potting method and the filling process of the magnetic core is an effective way to avoid the assembly failure of the board level magnetic core.