Improvement in Etching Factor of Micro Patterns by Controlling Residual Stress of Copper Thin Foil

2010 ◽  
Vol 123-125 ◽  
pp. 479-482
Author(s):  
Hyo Soo Lee ◽  
Hai Joong Lee

The effectiveness of residual stress on forming copper patterns of printed circuit board was investigated during applied thermal conditions. Generally, the electrolytic copper foil showed a compressive residual stress about -55~-60MPa as received, which easily caused to form copper patterns irregularly when the pattern was etched finely. The compressive residual stress was relaxed with applying heat-treatment for a few hours. However, we observed that the compressed residual stress of copper foil tended to be relaxed, constant, and compressed again during heat-treatment process, which is mainly considered as that the grain of copper is grown restrictively within a Cu thin foil layer. We suggested a quantitative method for controlling grain size, grain distribution and relaxing stress of copper foil, which was very helpful for increasing an etching factor to decrease pattern width.

2010 ◽  
Vol 654-656 ◽  
pp. 2716-2719
Author(s):  
Hyo Soo Lee ◽  
Hyouk Chon Kwon

The effectiveness of residual stress on forming copper patterns of printed circuit board was investigated during applied thermal conditions. Generally, the electrolytic copper foil showed a compressive residual stress about -54MPa as received, which easily caused to form copper patterns irregularly. We verified the compressive residual stress was relaxed with applying thermal conditions under 200°C for a few hours. And also, we observed that the compressive residual stress of copper foil tended to be relaxed, constant, and compressive again during heating times at each temperature. The relationships between residual stress and etching factor of copper pattern were analyzed in this works.


2014 ◽  
Vol 783-786 ◽  
pp. 692-697 ◽  
Author(s):  
Andrew Clark ◽  
Randy J. Bowers ◽  
Derek O. Northwood

The effects of heat treatment on distortion, residual stress, and retained austenite were compared for case-carburized 4320 steel, in both the austempered and quench-and-tempered condition. Navy C-ring samples were used to quantify both size and shape distortions, as well as residual stress. The austempering heat treatment produced less distortion and a higher surface residual stress. Both hoop and axial stresses were measured; the difference between them was less than seven percent in all cases. Depth profiles were obtained for residual stress and retained austenite from representative C-ring samples for the austempered and quench-and-tempered heat treatment conditions. Austempering maintained a compressive residual stress to greater depths than quench-and-tempering. Quench-and-tempering also resulted in lower retained austenite amounts immediately beneath the surface. However, for both heat treatments, the retained austenite content was approximately one percent at depths greater than 0.5 mm.


2020 ◽  
Vol 990 ◽  
pp. 283-287
Author(s):  
Yaw Jen Chang

This paper presents a simple approach to selectively synthesize the ZnO nanowires between interdigitated electrodes by integrating the hydrothermal method with the photolithography process. The printed circuit board (PCB) was adopted as the substrate. Interdigitated electrodes were fabricated by etching the copper foil of PCB. Then, both the positive and negative photoresists were used to control the growth of nanowires through lift-off concept. No costly materials and expensive apparatuses are required. Biotin–streptavidin reaction was used as an example to examine this proposed device. When histidine-tagged biotin was added and the reaction of biotin–streptavidin was completed, the distinguishable I-V curves were detected, respectively. The experimental results reveal that this proposed device is sensitive.


2011 ◽  
Vol 496 ◽  
pp. 259-265 ◽  
Author(s):  
Li Juan Zheng ◽  
Cheng Yong Wang ◽  
Yun Peng Qu ◽  
Li Peng Yang ◽  
Yue Xian Song

This work is focused on the investigation of the influence of the materials of PCB, feed rate, spindle speed and tool wear on thrust force when drilling PCB using 0.3 mm diameter cemented tungsten carbide drills. The results indicate that thrust force increases with feed rate and drill wear, but decreases with spindle speed firstly and then increases with it within the cutting range tested. Thrust force caused by the copper foil is much larger than that caused by the epoxy glass fiber cloth when feed rate is low. However, the difference between them decreases as feed rate increases. The thickness of nail head increases with thrust force. The accuracy of hole location increases with thrust force firstly but decreases afterward. The influence of thrust force on hole wall roughness is not obvious.


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