DFN0603 Packaging Wafer Backside Coating Process Design And Implementation

With the development of modern electronic products in the fields of portability,multi-function,high integration and high reliability,chip packaging technology is also developing in the direction of small size,fine spacing and fast heat dissipation.However,the traditional silver paste technology,epoxy,is distributed through the needle of syringe.With the decrease of chip size,the dispensing accuracy is more difficult to control,which directly affects the production efficiency and product quality.Now the highly competitive semiconductor industry,because the traditional solder joint process with chip size reduction,production efficiency and product quality stability and reliability can not be better guaranteed.Aiming at the above problems,this paper takes the technological process of DFN0603 packaging products,which is the main focus of our company,as the main research object.Based on the in-depth analysis of the theory and technical principle of the chip back gluing process,this paper conducts a detailed study and optimization of the chip bonding process design of our DFN0603 packaging products.Main contents:(1)Studied the mechanism of chip mounting,studied the characteristics of silver paste,and analyzed the quality hidden trouble caused by the introduction of new chip mounting process in combination with the actual situation,and proposed solutions.(2)Study and analyze the characteristics of different silver slurry,and select the silver slurry suitable for WBC(Wafer backside coating)process;Verify the effect of different coating thickness & baking time on product quality.The influence of different cutting speed & blade on product quality was studied.Through the experiment,find out the silver slurry,silver slurry thickness,adhesive thickness,blade,cutting speed & methods suitable for WBC process,solve the climbing problem of silver slurry,and ensure that the climbing height of silver slurry is between 20%-75% of chip thickness.(3)Find the appropriate DA heating temperature,welding force and time,curing temperature and time through DOE experiment;At the same time,the technology is applied to all DFN0603 products to improve production efficiency and solve the problem of climbing quality and yield of silver pulp.(4)Study the data of DFN 0603 package,find out the basic data conditions of new chip mounting process WBC and realize mass production,solve the problem of vision loss in the later stage test,and reduce the loss caused by the instability of chip bonding process by about 3%.