高阶HDI软硬结合板+cavity技术研究

Research on high-order HDI rigid-flex PCB+cavity technology

智能电子产品轻薄化及多功能化的发展趋势,必然推动PCB结构向线路精细化及通盲孔小型化的方向发展,其中,受高断针率、高成本因素影响,小孔径通孔应用范围受限。为了解决PCB组装工艺难及成本高的问题,采用在高阶HDI产品上面增加Cavity设计结构,以两块板替代原来的“三明治”结构,满足HDI主板大容量、多功能、高传输速度及小型化的要求,并降低生产成本。实现这技术方案的关键就在于开发一种稳定可靠的高阶HDI+Cavity工艺制作方法,以满足PCB及元器件的组装要求。文章还研究采用软板UV镭射激光钻65um的通孔替代盲孔,解决盲孔填孔结构底部开裂品质隐患,增层后制作75μm盲孔并填孔,验证其信赖性与可靠性。研究结果表明,高阶HDI软硬结合板+Cavity技术能够满足PCB产品品质要求,对小孔径通孔的应用起到积极推动作用。

The development trend of intelligent electronic products'lightweight and multi-function will inevitably promote the PCB structure to the direction of circuit refinement and miniaturization of through and blind holes.Among them,the application scope of small through-hole is limited due to high needle breakage rate and high cost factors.In order to solve the problem of difficult PCB assembly process and high cost,a Cavity design structure is added to the high-order HDI products,and the original"sandwich"structure is replaced by two boards to meet the requirements of HDI motherboards for large capacity,multi-function,high transmission speed and miniaturization,and reduce production costs.The key to realize this technical scheme is to develop a stable and reliable high-order HDI+Cavity process manufacturing method to meet the assembly requirements of PCB and components.This paper also studies to replace the blind hole with a 65 mm through hole drilled by a flex UV laser to solve the hidden crack quality problem at the bottom of the blind hole filling structure.After adding layers,a 75 mm blind hole is made and filled to verify its reliability and reliability.The research results show that the high-order HDI soft and hard combination board+activity technology can meet the quality requirements of PCB products and play a positive role in promoting the application of small aperture through-hole.