| The rapid development of modern electronic information technology,the requirements of electronic products are miniaturized,portable and multi-function, high reliability and low cost. In order to meet the requirements of various electronic products,Electronic packaging has developed a wide range of packaging technology,emerged a large number of new theories,new materials,new processes and new products.Electronic Packaging is working with the electronic design and manufacturing to jointly promote the information society development.Epoxy molding compound (Epoxy Molding Compound,EMC) is an electronic packaging material,which is mainly used to protect semiconductor chip package. Epoxy molding compound for its low-cost,high production efficiency,and reasonable reliability characteristics,has become the most important and the most common packaging materials of semiconductor packaging. It is followed by semiconductor technology and semiconductor packaging technology and the development of epoxy molding compound technology also promote the development of semiconductor technology and semiconductor packaging technology. As the performance of electronic products and the use of continually increasing demands of the microelectronics packaging materials are also put forward higher requirements updated. To meet the ultra-thin,miniature,high performance,multi-functional,low cost and the requirements of green packaging materials,electronic packaging is currently the most important issue facing the development. Therefore,the epoxy molding compound as the major micro-electronics packaging materials,are also facing unprecedented opportunities and challenges.O-cresol formaldehyde epoxy resin with excellent thermal stability and chemical stability,excellent moisture performance,has become the most widely used epoxy molding compound resin matrix. However,a larger o-cresol formaldehyde epoxy resin melt viscosity can not meet the requirements of increasing filler content. And the new packaging technology and use requirements demand epoxy resin of electronic packaging to improve. Biphenyl type epoxy resin in a single molecule as a crystal, melt viscosity is very low (0.01Pa ? S when 150°C),can fill a large number of spherical fused silica filler,and decrease thermal expansion coefficient of epoxy molding compound. Biphenyl type epoxy resin is the preferred basis of low stress, low thermal expansion of epoxy resin molding compound.Based on this, first, we use two-step method to synthetise 3,3',5,5'-tetramethyl diphenyl-4,4'-diol epoxy resin (TMBP),and characterize its structure with FT-IR, 1H-NMR and DSC. And then adding it to o-cresol formaldehyde epoxy resin (ECN) as melt blending mode. Blends , respectively 4 , 4'- diaminodiphenyl methane (DDM) and 4,4' - diaminodiphenyl sulfone (DDS) as curing agent are studied comparatively. Dynamic non-isothermal DSC is used to study 3,3',5,5'-tetramethyl diphenyl-4,4'-diol epoxy resin (TMBP)/o-cresol formaldehyde epoxy resin (ECN) blends curing conditions in order to define time and temperature of DDM and DDS curing blends.In the fourth chapter , the thermal properties , mechanical properties , morphology and water absorption of DDM and DDS curing blends are tested respectively. First using DMA and TGA to DDM as curing agent on the TMBP/ECN blends make a comprehensive study for thermal properties.With the TMBP content increased,the relative non-modification of the former,whether the glass transition temperature or weight loss temperature blends are greatly improved. After TMBP modified,TMBP/ECN blends performance in the impact has also been improved in some extent. The SEM observations show that following the increasing TMBP content,the fracture surface of cured blends gradually transit to fish scale fracture from ECN's drawing shape as toughness increased.The amount of water absorption of TMBP/ECN blends essentially unchanged.Then using the same method,DDS-TMBP/ECN blends are studied.Results show similar laws with DDM-TMBP/ECN blends. Only because of the melting point of DDS higher than DDM,its thermal properties of cured epoxy resin is also higher than the DDM curing agents,which is due to the main chain sulfonyl structure of DDS.While the lone electron pair of DDS sulfonyl oxygen atom easily to form hydrogen bonds with water resulting that water absorption of the DDS system is higher than the DDM system.
|
PDF Full Text Request