本发明涉及一种铜合金及其制备方法和应用。本发明的铜合金，通过Zn、Fe、Cr、Sn、Si和Mg之间的相互作用，可以在铜基体中引入多种强化相，使合金元素以高硬度、高耐热的纳米级FeSi和Cr相颗粒充分弥散析出，强化析出相颗粒和位错之间的交互作用，实现了多相协同弥散强化、应变强化、亚晶强化和固溶强化的综合强化作用，同时提高了铜合金的综合性能，解决了现有铜合金的强度、导电性能、抗软化性能、低残余应力难以兼顾和匹配的问题。本发明还提供了上述铜合金的制备方法和由上述铜合金制备的蚀刻型引线框架。

The present invention relates to a copper alloy and its preparation method and application. The copper alloy of the present invention can introduce various strengthening phases into the copper matrix through the interaction between Zn, Fe, Cr, Sn, Si, and Mg, allowing the alloy elements to fully disperse and precipitate with high hardness and high heat resistance nanoscale FeSi and Cr phase particles, strengthening the interaction between the precipitated phase particles and dislocations, and achieving a comprehensive strengthening effect of multi-phase synergistic dispersion strengthening, strain strengthening, subgrain strengthening, and solid solution strengthening, At the same time, it improves the comprehensive performance of copper alloys and solves the problem of difficulty in balancing and matching the strength, conductivity, softening resistance, and low residual stress of existing copper alloys. The present invention also provides a preparation method for the above-mentioned copper alloy and an etching type lead frame prepared from the above-mentioned copper alloy.