高性能电子银粉自动化反应系统研制

发布时间：2018-05-19 21:03

本文选题：电子银粉 + 正银浆料　；参考：《华中科技大学》2014年硕士论文

【摘要】：电子银粉是高性能导电浆料的关键材料，其形貌、粒径大小、粒度分布等直接影响浆料的丝网印刷性能和电气性能。太阳能电池正银浆料作为一种新型的导电浆料对电子银粉的性能提出了较高的要求。化学还原法是制备银粉的主要方法，该方法就是使用还原剂把银离子从其化合物溶液中还原为银单质，并以粉末的形式沉积出来。反应过程中的主要工艺参数，如搅拌速度、溶液PH值、反应温度等对银粉的性能有直接影响。论文在分析液相化学还原法反应原理的基础上，设计了一套基于PLC与HMI的自动化反应系统。该系统采用异步串行方式使PLC与二次仪表进行通信，实现了反应釜中搅拌速度、溶液PH值、反应温度等工艺参数的自动控制。系统的硬件设计主要包括三部分：采用S7-200PLC与MM440变频器通信，实现搅拌速度的控制；采用PID控制算法，由PLC、PH仪表、PH电极、电磁阀等实现溶液PH值的控制；采用温控仪表，由热电偶、晶闸管、电热丝等实现反应温度控制。触摸屏作为上位机通过PPI协议与PLC通信，采用Modbus RTU协议与PH仪表、温控仪表通信，实现对系统的操作控制。系统的软件设计采用STEP7-Micro/WIN对PLC进行编程，设计了系统控制程序，并利用EasyBuilder8000设计了操作界面。系统具有定时、参数设置、数据记录与查询、密保等功能，操作简单、功能完善。在系统完成后，进行了银粉制备试验，，并对制得的银粉进行了扫描电镜（SEM）分析和粒度分布测试，选取性能较好的银粉制成了银浆，在单晶硅片上进行印刷、烧结，制成太阳能电池片，对电池片的性能进行了测试，结果表明电池的转换效率等指标达到了较好的水平。反应系统经实际使用，运行稳定、可靠，系统的结构合理、操作方便，能生产出一致性好、粒度均匀，球形度较好的高性能电子银粉。
[Abstract]:Electronic silver powder is the key material of high performance conductive paste. Its morphology, particle size and particle size distribution directly affect the screen printing and electrical properties of the paste. As a new type of conductive paste, solar cell silver paste has put forward higher requirements for the performance of electronic silver powder. Chemical reduction is the main method of silver powder preparation. The method is to reduce silver ion from its compound solution to silver simple substance and deposit it as powder. The main process parameters, such as stirring speed, pH value of solution and reaction temperature, have a direct effect on the properties of silver powder. On the basis of analyzing the principle of liquid-phase chemical reduction reaction, an automatic reaction system based on PLC and HMI is designed. The system uses asynchronous serial mode to make PLC communicate with the secondary instrument, and realizes the automatic control of stirring speed, pH value of solution, reaction temperature and other technological parameters in the reactor. The hardware design of the system mainly includes three parts: using S7-200PLC to communicate with MM440 frequency converter to realize the control of stirring speed; using PID control algorithm to realize the control of PH value of solution by PLC PH instrument, PH electrode, solenoid valve and so on; using temperature control instrument, adopting temperature control instrument, The reaction temperature is controlled by thermocouple, thyristor and electric wire. The touch screen communicates with PLC through PPI protocol, and uses Modbus RTU protocol to communicate with PH instrument and temperature control instrument to realize the operation and control of the system. The software design of the system uses STEP7-Micro/WIN to program the PLC, designs the control program of the system, and designs the operating interface by using EasyBuilder8000. The system has timing, parameter setting, data recording and query, secret protection and other functions, simple operation, perfect function. After the completion of the system, the silver powder preparation test was carried out, and the silver powder was analyzed by scanning electron microscope (SEM) and the particle size distribution was tested. Silver paste was made from the silver powder with good performance, and the silver powder was printed and sintered on the single crystal silicon wafer. The performance of the solar cell is tested. The results show that the conversion efficiency of the battery has reached a good level. The reaction system has been used in practice, running stably and reliably, the structure of the system is reasonable, the operation is convenient, and the high performance electronic silver powder with good consistency, uniform particle size and good sphericity can be produced.
【学位授予单位】：华中科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM914.4

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