Study On The Relationship Between Molding Defects And Processing Parameters For The Radio Frequency Module

The low temperature co-fired ceramics(LTCC) technology has advantage over other traditional packing technologies for its excellent high frequency characteristics, fine line and spaces, but it is easy to cause defects of its complicated process. Researching the relationship between defects and the main factors among many factors caused defects is not only the foundation to accurately control the processing parameters, but also an important prerequisite for manufactured high quality products. Focus on the radio frequency(RF) module, this paper uses the method of theoretical analysis and simulation to analyze the defects for molding process of LTCC technology, and models the relationship between defect evaluation and the main influencing factors of molding defects, its purpose is to optimize the processing parameters and improve the molding quality of RF module. This paper studies on following aspects:(1) Numerical simulation for the molding defects.Four main molding defects are proposed according to the problems of trial samples, they are micro-channel deformation, substrate warping, vertical interconnect dislocation between layers, eutectic solder voids. The formed mechanisms are researched through theoretical analysis. According to the formed environment of molding defects, ANSYS Workbench is used to complete the simulation for four molding defects.(2) Influencing factors Analysis for molding defects.The objective functions of defects are determined based on the size, texture, shape and other features of defects which impact the molding quality and functional properties of module. On this basis, the simulation analysis of defects under multiple sets of processing conditions is completed by orthogonal test method, the main influencing factors are extracted from the affecting factors of molding defects.(3) Development of mathematical model to account for the relationship between molding defects and processing parameters.Multi-level orthogonal test is completed on the basis of the identification of the main influencing factors, while other secondary factors are chosen suitable values which are favorable for the molding quality. The relationship models between defect evaluation and the main influencing factors are established based on the response surface method and Marquardt method.(4) Verification the accuracy of relationship model by experiment.To ensure the correct analysis, corresponding detection methods are used to detect the molding defects of trial samples which are made under different processing conditions. By comparing the assay results with calculation of the theoretical model, the results of the simulation analysis can be accepted and the accuracy of the relationship model is better than 80%.