Research On New MEMS Device Electronic Packaging Technology

Electronic packaging technology is one of many key technologies in the production of MEMS products.Packaging technology and package quality directly affect the electrical performance,reliability,and durability of the product.In general,MEMS device package form includes full hermetic package,molding,WLP(wafer-level package),pre-Molding package and BGA(ball grid array package)package.This article introduce the full hermetic package and WLP.The technology and problems of molding,pre-Molding package and BGA package were studied.The works are not only benefit to improve the reliability and electrical performance of MEMS device packages,but also to ensure the packaging yield of MEMS devices and to reduce the production cost.The content of the paper mainly includes the following aspects:1.We researched and analyzed the traditional molding process flow and pre-Molding package process flow of MEMS device electronic packaging;The structural problems of the package are analyzed.And the related issues of lead frame,chip adhesive and molding compound related issues used in the MEMS device package are analyzed.The wire bonding machine,the splicer,molding M/C and other technical equipment involved in MEMS device packaging are introduced.2.Substrate design and lead frame design that have a key influence on the electrical performance of MEMS device packages have been studied in depth.Taking a study of a BGA substrate design as an example,analysis the impact of material properties on the electrical performance of the substrate,and carry on the simulation.It has been found that using BT resin as a packaging substrate material enables the substrate to achieve desirable electrical properties.The study from the substrate stack layout design to the wiring design,and to the electrical simulation;The design of the same substrate was carried out with two different design schemes,the similarities and differences of the two design methods and their advantages and disadvantages are analyzed and compared in electrical aspects.It has been found that the substrates designed by the two schemes have advantages and disadvantages in terms of wire bonding design,wiring design,transmission delay,RLC parameters,and signal crosstalk.3.The design method of the QFN lead frame is introduced,an improved design of the QFN lead frame on the large pad and the pin pad is studied,the improved lead frame effectively improves the reliability of the electrical performance of the MEMS device package in the later period.4.The reasons for flash in the manufacturing of MEMS device package pre-molded tube shells and the effect of mold flash on lead on the electrical properties of the MEMS device package were analyzed.Analytical study of flash from three positions of mold flash from the mold cavity,the back of the lead frame,and the front of the lead frame,The technical solutions for solving the problem of flash were proposed separately.Through the analysis of the packaging process,collaborative adjustment of clamp pressure,transfer pressure,transfer time and other process parameters ideally solves the problem of flash of a pre-molding tube shell used for MEMS device packaging.