【作者】 王晨；

【导师】 高胜东；

【作者基本信息】 哈尔滨工业大学 ， 机械制造及其自动化， 2018， 硕士

【摘要】 近年来,人们对电子产品的要求逐渐提高,需求量也逐渐增长,因此电子产品更新换代的速度非常高。为实现电子产品的轻小化与低成本,对微电子封装用BGA焊锡球和表面贴装的制作方法的研究显得十分重要。微滴喷射成型技术在上世纪90年代被提出且得到快速发展,其喷射过程能被精确的控制,为BGA焊锡球的制作及表面贴装的发展提供了一个新的方向。本课题为了实现对均匀BGA焊锡球的制作及锡膏的喷印成型,开发了一套基于气动式原理的金属微熔滴按需喷射及沉积系统,用该系统制得了均匀的无铅焊锡颗粒,讨论了生成颗粒的影响因素,并对其喷射成型进行了初步的实验。本文主要开展了以下的研究工作:本文首先对金属微熔滴按需喷射过程进行仿真分析,分别研究了在气体脉冲的作用下,坩埚内气体压力的变化情况和液滴的喷射过程。利用单因素变量法模拟了不同参数下坩埚内的气压波动,并分析了不同参数对气压波动的影响。改变仿真参数,得到了不同的液滴喷射状态,对液滴的不同喷射状态及其压力场进行分析,同时研究了喷射参数对液流的伸长及喷射速度的影响规律。通过对金属微熔滴按需喷射及沉积系统功能的分解,确定了每个功能具体的实现方案。设计系统的气路实现对系统氧浓度的降低,并对喷射装置实现供气。利用数据采集卡产生的信号控制电磁阀通断,在压力的作用下产生气体脉冲驱动液滴的生成。选用运动控制卡控制步进电机平台的方式对运动系统进行搭建,同时设计运动控制的电路。选用Lab VIEW软件对系统的驱动程序进行编写,实现了喷射打印功能。将上述设计的系统进行集成,用集成的系统进行喷射实验,确定了某一条件下的喷射状态,验证了系统的可行性;通过单因素实验法分析了实验参数对生成的液滴直径及均匀性的影响趋势。利用系统进行了沉积实验,对打印的线阵列和面阵列进行了精度的分析;重复进行二维图形打印,得到了简单的三维制件。实验证明了系统能产生不同尺寸的均匀焊球,同时验证了系统具有喷印成型的能力,能实现液滴的堆叠。更多还原

【Abstract】 In recent years,people’s requirements for electronic products have gradually increased,and the demand has gradually increased.Therefore,the rate at which electronic products are upgraded is very high.In order to reduce the size and cost of electronic products,it is very important to study the fabrication methods of BGA solder balls and surface mounts for microelectronic packaging.Droplet injection molding technology was proposed and developed rapidly in the 1990 s.The injection process can be precisely controlled,providing a new direction for the development of BGA solder balls and the development of surface mount.In order to realize the production of uniform BGA solder balls and the printing and molding of solder paste,this project developed a set of on-demand metal droplet spraying and deposition system based on the pneumatic principle.Uniform lead-free solder particles were obtained using this system.The influencing factors for the formation of particles were discussed and preliminary experiments were carried out on their injection molding.This article mainly carried out the following research work:In this paper,firstly,the on-demand injection process of metal micro-droplets is simulated and analyzed.Under the action of gas pulse,the change of gas pressure in the crucible and the ejection process of the liquid drop are studied.The single-factor variable method was used to simulate the pressure fluctuations in the crucible under different parameters,and the influence of different parameters on the pressure fluctuation was analyzed.By changing the simulation parameters,different droplet ejection states were obtained,and the different ejection states and pressure fields of the droplets were analyzed.At the same time,the influence of ejection parameters on the fluid flow elongation and ejection velocity was studied.Through the on-demand injection of metal micro-droplets and the decomposition of the deposition system’s functions,the specific implementation of each function was determined.The gas path of the system is designed to achieve a reduction in the oxygen concentration of the system and a gas supply to the injection device is achieved.The signal generated by the data acquisition card is used to control the on-off of the solenoid valve,and a gas pulse is generated under the action of the pressure to drive the generation of the droplet.The motion control card is used to control the stepping motor platform to build the motion system,and the motion control circuit is designed at the same time.Lab VIEW software was used to compile the system driver program and achieve the jet printing function.The above-designed system was integrated and the integrated system was used for the injection experiment.The injection condition was determined under certain conditions and the feasibility of the system was verified.The single-factor experiment method was used to analyze the droplet diameter and uniformity of the experimental parameters.The trend of sexual influence.The deposition experiments were performed using the system,and the accuracy of the printed line arrays and surface arrays was analyzed;twodimensional graphic printing was repeated and simple three-dimensional articles were obtained.The experiment proves that the system can produce uniform solder balls of different sizes.At the same time,it verifies that the system has the ability of jet printing and can realize the stacking of droplets.更多还原