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随着电子产品应用技术的不断更新以及功能的完善,板件的散热性能要求越来越高,因此大量的散热密集孔设计应用于印制线路板,由此带来散热密集孔分层的问题。本文通过对密集散热孔裂纹区域的分析、研究,对VIP散热密集孔设计、钻孔参数、烘烤参数进行了试验验证,并提出了散热密集VIP孔爆板分层改善的方向。 相似文献
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以一款16层的叠孔三阶HDI板的制作为例,讲述该类产品的制作难点、控制重点和注意事项等,为同行技术工作者制作该类产品提供参考。 相似文献
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随着目前电子产品不断朝小型化、轻便化、多功能化的方向发展,高密度互连HDI印制板势必会广泛应用于各种电子产品。文章主要介绍了一种叠孔制作时各个细节控制方法及薄板采用垂直电镀工艺进行填孔电镀的可行性。 相似文献
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Electro-chemical mechanical planarization (ECMP) process dissolves copper ions electrochemically by applying an anodic potential on the copper surface in an aqueous electrolyte, and then removes a copper (Cu) complex layer by the mechanical abrasion of a polishing pad or abrasives in the electrolyte. The ECMP process is a low pressure polishing method for metals such as copper, aluminium (Al) and tungsten (W) on dielectric materials such as silicon dioxide, low-k (LK) and ultra low-k (ULK) dielectrics, comparing to the amount of defects by the traditional Cu chemical mechanical planarization (CMP). The polishing pad used in the ECMP process is a conventional closed cell type pad (IC 1400 K-groove pad) with holes. It supplies the aqueous electrolyte to the copper surface and removes the copper complex layer. The material removal rate (MRR) and MRR profile were simulated and tested according to the changes of the wafer overhang distance (WOD) from the platen and the electric contact area (ECA). In order to derive the design rule of the system, the experimental results are compared with the simulation results. After the ECMP process, it was verified that the within wafer non-uniformity (WIWNU) was lower than 2% using the relatively uniform ECA pad (C-type) under the smallest WOD condition. The experimental results well matched the simulated results. 相似文献
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关于厚板镀厚铜要求的电镀探讨与实践 总被引:1,自引:0,他引:1
文章讨论了厚铜箔PCB板镀铜和图形电镀铜的生产制作工艺,指出厚铜箔PCB普遍存在的孔铜厚度不均匀和一般厚度偏低的解决途径和操作方案。 相似文献
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Electroless Ni/Immersion Au interconnects: Investigation of black pad in wire bonds and solder joints 总被引:1,自引:0,他引:1
Black Pad was observed on Electroless Ni/Immersion Au (ENIG) wire bond pads. Thick immersion Au on highly corroded electroless
Ni was detected. It was determined that the pads were electrically connected to the Cu ground plane due to a Ni bridge formed
inside normally open photovias. The mechanism of the bridge formation was verified and preventative actions were taken; it
was demonstrated that formation of Black Pad could be switched on and off. The mechanism of Black Pad formation is proposed
to be defective ENIG plating involving variation of both the electroless Ni and immersion Au plating processes. The intermetallic
structures of solder joints on the above pads were studied. The study was conducted on both defective and non-defective pads
to show differences in intermetallic structure and composition. Me2Sn4 and Me2Sn2 (Me=Cu, Ni, and Au) intermetallics were formed on non-defective pads, which nucleated on the Ni layer and grew inside the
molten solder. However, only the Me3Sn intermetallic was formed on defective pads inside the corroded Ni Layer. Both mechanisms of intermetallic formation were
found on pads with mildly corroded Ni and intermediate Au thickness (4.5–7 in). 相似文献
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“电路理论”课堂教学探讨 总被引:1,自引:0,他引:1
本文结合具体实例对电路理论课堂教学过程中的几个重点问题,即电压和电流关联与非关联参考方向、等效的概念及等效变换、受控电源的处理及正弦稳态电路的相量分析等问题做了详细的分析,并总结了便于学生学习和理解的教学思路,为电路理论的教学提供了有益的建议。 相似文献
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杆轨电路能完成机电间的等效,对其的理论研究具有一定的意义,在实际应用中也有较为广阔的前景。本文讨论包括两个方面,一是把电学参量等效为力学参量,二是用力学元件组装成电学元件。通过磁场、动生电动势及杆轨电路,可将机电紧密结合于一体。 相似文献
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