| 1. | Screen printing technology for solder ball flip chip for smt
倒装芯片及晶圆和基底凸起的网版印刷技术一 |
| 2. | So it will result in rigidity skin & block and solder balls etc
产生的后果是：锡膏出现硬皮、硬块、难熔并产生大量锡球等。 |
| 3. | Its development is based upon the solution of the reliability of solder ball , which is one of the key problems
而焊点可靠性问题是发展bga csp技术需解决的关键问题之一。 |
| 4. | This could cause a variety of solder defects , ranging from solder balling to non - wetting to damaged devices to voiding to charred residues
这样会产生许多焊接缺陷，诸如锡球、润湿不良、破坏元器件、空洞、碳化等。 |
| 5. | Often confused with solder balling , solder beading is a defect recognized by one or a few larger balls , generally located around chip caps and resistors
锡珠经常会和锡球混淆，锡珠一个或几个大的球，通常会位于小电容或电阻旁边。 |
| 6. | Since solder balls do oxidize quickly and builds an oxide coat that reduces the soldering characteristic of the ball , the chips should be vacuum sealed shortly after the reball process
因为很容易氧化并且形成一个氧化层覆盖会降低锡球的焊接特性，所以在重新植球加工后应尽快真空封装。 |
| 7. | It is proved that thermal fatigue is the main cause of the invalidity of the package . therefore , it is significant to research the reliability of solder ball under the thermal cycle
实践证明热作用是芯片封装组件失效破坏的主导因素，因此热循环条件下的焊点可靠性研究有着非常重要的意义。 |
| 8. | In the five key factors of solder ball alloy , solder paste alloy , peak temperature , the time above liquidus and soldering environment , the fore four factors are more important than soldering environment to the solder joints reliability
在焊球合金、焊料合金、峰值温度、液相线以上时间和焊接环境五个关键因素中，前四项对焊点可靠性比较重要，焊接环境对焊点可靠性的影响不很显著。 |
| 9. | In this paper , bga / csp is simulated and analyzed as implemented in the ansys finite element simulation software tool to evaluate the affect on its reliability ; the constitutive model of the solder ball is constructed tentatively to find a better description for the solder ball
为此，本文基于大型商用有限元软件ansys ，对bga csp形式的封装进行模拟，并在此基础上对多种情况进行对比分析，以此来评价各种因素对其可靠性的影响，从而来提高该封装的可靠性。 |
| 10. | Zhang liji ( material physics and chemistry ) directed by professor xie xiaoming this paper is intended to solve problems for those who are designing , using pbgas . failure mechanism , as well as cycles to failure of two groups of pbga samples ( with / without underfill ) for thermal cycling conditions in the range of - 40 ~ 125 , were presented . the experiment shows that solder ball in the samples without underfill cracked after 500 times cycle , no crack was found in the underfilled samples even after 2700 cycles
通过一系列的实验，得到以下实验结果： ?在本论文设定的温度循环条件下，未充胶pbga样品的热疲劳品寿命在500周左右，充胶样品的焊点寿命高于2700周； ?对于未充胶器件，中心距( dnp )是决定焊点应力、应变大小的最主要因素，裂纹总是从中心距较大处萌生并向中心处扩展； ?温度循环的过程中焊盘附近焊料组织明显粗化。 |
