铜镀层对IC引线框架表面抗氧化失效的作用

The Role of Surface Electroplated Cu on Oxidation Failure of Lead Frame for IC Package

研究了在铜合金表面电镀纯铜层保护膜对铜合金引线框架氧化失效的影响.研究发现,电镀纯铜层后,纯铜层氧化速率较高,氧化膜较厚,然而,由于纯铜层的阻挡作用,可以使氧化只发生在纯铜层上,减少CuO的生成.当铜合金表面的电镀纯铜层厚度超过一个临界值,表面电镀纯铜处理可以明显改善材料的耐氧化剥离性.表面电镀前的铜合金氧化膜结构为CuO/Cu2O/Cu.电镀纯铜层后,氧化膜结构变为Cu2O/Cu,当氧化膜主要由Cu2O构成时,氧化膜结合强度较高.

The effects of surface electroplate pure copper on oxidation failure of lead frame copper alloys for IC package were investigated.Pure copper layer will benefit the diffusion of copper ion,so,the thickness of copper oxide films increases but the velocity of CuO formation decreases and the oxidation only occurs at pure copper layer.As the electroplating pure copper layer on copper alloy exceeds a critical thickness,the surface electroplating treatment can improve the copper alloy's resistance against oxidation failure greatly.The oxide film structure of copper alloys is CuO/Cu_2O/Cu substrate,after electroplate treated,and the oxide film structure is changed to Cu_2O/Cu.The oxide films with only Cu_2O have higher adhesion strengths.