New Silver Alloy Bonding Wire Based On Environmental Friendly Cathodic Passivation Protection And Its Application

Microelectronic packaging components are widely used in military products,smart phones and driverless vehicles.Driven by the trend of high density,high integration and miniaturization,the requirements of packaging technology,materials and product quality are becoming higher and higher.As one of the four key basic materials in the field of microelectronic packaging,Bonding wire is the internal lead to realize the electrical interconnection between chip and lead frame.Its quality directly determines the performance of microelectronic packaging products.As a non-traditional bonding wire,silver alloy wire has excellent conductivity,ductility,high reflectivity and excellent performance.It is the main direction to replace traditional bonding wire in the future.However,the bonded wire with high silver content is prone to silver ion migration under wet conditions,and is prone to surface discoloration caused by sulfide and oxygen corrosion in the air,which affects the reflectivity,long-term reliability and service life of the silver wire.This paper based on the new environmentally friendly trivalent chromium cathode passivation technology.In order to obtain a smooth,dense nano-scale film coated silver-based bonding wire.Under the premise of not affecting the bonding reliability and reducing the light reflection,a new low-cost and high-quality silver bonding wire anti-corrosion method is realized.This paper mainly exploring the effective process parameters of the new environmentally friendly trivalent chromium cathode passivation technology,studying the effects of different current I,voltage U and passivation time T o n the surface quality of the silver wire,and verifying the silver bonding wire's Passivation and corrosion resistance under the final process parameters;Using X-ray Photoelectron Spectroscopy and Energy Dispersive Spectrometer,analyzing the passivation film composition on the surface of silver-based alloy wires;And By means of KAIJO bonding machine and Condor Sigma testing machine,testing the bonding properties of the 1^st Bond diameter D and the breaking force F of the silver-based alloy bonding wire.The application of2835 LED lamp beads is realized by packaging technology.Under constant temperature and humidity test box,high precision fast spectral radiometer and other instruments,the reliability of silver reflectivity and light flux decay a fter double 85 accelerated aging were studied,and Finally,analyzing the Tafel curve of trivalent chromium salt in acidic and alkaline conditions,cyclic voltammetry curve and cathodic polarization curve of TS passivation solution.Analysis the cathodic reaction process and film forming mechanism of trivalent chromium cathodic passivation solution.