大功率IGBT器件的结构设计优化

发布时间：2018-04-05 00:37

本文选题：大功率IGBT　切入点：电场仿真　出处：《华北电力大学(北京)》2017年硕士论文

【摘要】：随着大功率IGBT器件的快速发展,如4.5 kV和6.5 kV电压等级器件的市场化,在牵引运输、电力系统领域将有能力与基于晶闸管的电流驱动型器件进行竞争。但是由于常规的焊接式IGBT器件主要存在两种失效问题,即铝引线键合点脱落和焊料层失效,故借鉴晶闸管封装形式,通过采用压力接触封装的新型压接式IGBT器件得到了广泛关注。因此,本文针对新型压接式大功率IGBT器件的设计,基于数值计算的方法,研究器件的绝缘问题,并通过仿真对器件的结构设计进行优化和指导,同时缩短器件的研发周期,具有重要的实际意义和应用价值。本文的研究内容基于器件的结构主要包括了三个方面,由内到外分别是芯片终端区结构,子模组封装结构和管壳结构研究。首先,通过建立的IGBT芯片终端区的模型,分析了场限环多个变量如场限环的宽度、间距、个数等对芯片击穿电压的影响,并根据初始的设计进行优化,得到了优化后的结构。随后,本文开展了基于有限元的电场仿真计算,建立了IGBT芯片子模组的仿真模型,提出并分析了三个电场强度集中的区域,即纵向间隙、横向间隙和银片与框架间隙,并针对相应的区域,提出了施加电阻层和增加间隙两种实际可行的改进措施。最后,针对大功率压接式IGBT管壳设计,从目前的可参考标准和有限元电场仿真两个方向出发,对器件管壳的绝缘设计进行校核。另外,在仿真中分析得到如果子模组与管壳距离过近,加之管壳过薄,那么内部子模组的电场强度分布会一定程度上影响到管壳内外表面的电场强度分布,故在实际的设计中需要考虑一定的裕度。
[Abstract]:With the rapid development of high-power IGBT devices, such as the marketization of 4.5 kV and 6.5 kV voltage grade devices, the field of traction transportation and power system will be able to compete with the thyristor based current-driven devices.However, there are two main failure problems in conventional solder IGBT devices, that is, aluminum lead bond joint shedding and solder layer failure, so the thyristor packaging form is used for reference.A new type of pressure-bonded IGBT device with pressure contact packaging has been paid more and more attention.Therefore, based on the numerical calculation method, this paper studies the insulation of the new type of high-power IGBT devices, and optimizes and guides the structural design of the devices through simulation, and shortens the research and development period of the devices.It has important practical significance and application value.The research content of this paper is based on the structure of the device, which includes three aspects: chip terminal structure, submodule encapsulation structure and shell structure from inside to outside.Firstly, through the model of the terminal area of IGBT chip, the influence of several variables such as the width, spacing and number of the field limiting ring on the breakdown voltage of the chip is analyzed, and the optimized structure is obtained according to the initial design.Then, the electric field simulation calculation based on finite element method is carried out, and the simulation model of IGBT chip submodule is established, and three regions of electric field intensity concentration, that is, longitudinal gap, transverse gap and silver sheet and frame gap, are proposed and analyzed.According to the corresponding region, two practical and feasible improvement measures are put forward, which are applying resistor layer and increasing gap.Finally, aiming at the design of high-power IGBT tube and shell, the insulation design of the tube and shell is checked from the two directions of the current reference standard and the finite element electric field simulation.In addition, if the distance between the submodule and the shell is too close and the shell is too thin, the electric field intensity distribution of the inner submodule will influence the distribution of the electric field intensity on the inner and outer surface of the tube and shell to some extent.Therefore, a certain margin should be considered in the actual design.
【学位授予单位】：华北电力大学(北京)
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN322.8

【参考文献】