PCB“应力型”内层连接缺陷探究

Study on stress type inner connection defect of PCB

随着印制电路板(PCB)层数越来越多,内层铜与孔铜连接的品质可靠性也越来越受关注。通常由于化学镀铜层与电镀层结晶不同,且板材与铜的膨胀系数不同,内层连接位置在应力作用下产生应力型内层连接缺陷(ICD)。通过对ICD切片3D显微镜和聚焦离子束(FIB)分析界定了应力型ICD (非钻污残留),探究了在生产制程中针对应力型ICD的管控和改善方法。

The increase in the number of printed circuit board(PCB)layers leads to more inner connections in plating through holes(PTHs).More and more attention is paid to the quality and reliability of the connection between inner copper and hole copper.Generally,due to the difference of crystalization between PTH copper and plating copper,as well as the difference in coefficient of thermal expansion between board substance,stress type factor of resins and copper also different,inner connect bits have inner connection defects(ICD)appear under stress.This paper analyzes the ICD microsection through 3D microscope and focused ion beam(FIB)analysis,defines the stress type ICD(non-resin residue),and explores the control and improvement method of stress type ICD in manufacture process.