whisker growth
Recently Published Documents


TOTAL DOCUMENTS

443
(FIVE YEARS 44)

H-INDEX

30
(FIVE YEARS 3)

2022 ◽  
Vol 7 (1) ◽  
pp. 7
Author(s):  
Jacob D. Buchanan ◽  
Vamsi Borra ◽  
Md Maidul Islam ◽  
Daniel G. Georgiev ◽  
Srikanth Itapu

Whiskers are small crystalline growths, which can grow from certain metals or alloys. Reaching up to several millimeters long, whiskers have the potential to cause device failures due to short circuits and contamination by debris. Tin (Sn) is one such metal that is particularly prone to whisker development. Until the 2006 RoHS Initiative, lead (Pb) was added to tin in small amounts (up to 2%) to greatly reduce the growth of whiskers. Since then, however, industry has switched to lead-free tin solders and coatings, and the issue of whisker growth on tin has attracted new interest. A reactive-sputtering-deposited nickel oxide sublayer was shown recently to strongly suppress the growth of whiskers from an overlaying tin layer. This paper reports on using nickel oxide films, obtained by a sol–gel dip coating method, as whisker suppressing sublayers. The proposed method is simple, low-cost, and can easily be scaled up for manufacturing purposes. The properties of the sol–gel deposited nickel oxide film were examined using SEM, EDS, and Raman spectroscopy. Samples containing the nickel oxide sublayer were observed through SEM periodically over several months to examine the surfaces for whisker development, and the results show that such layers can be very effective in suppressing whisker growth.


Ecosphere ◽  
2021 ◽  
Vol 12 (11) ◽  
Author(s):  
Marie R. G. Attard ◽  
Anna Lewis ◽  
Stephen Wroe ◽  
Channing Hughes ◽  
Tracey L. Rogers

2021 ◽  
Vol 63 (11) ◽  
pp. 988-993
Author(s):  
Cagatay Elibol ◽  
Horst Paul Strunk

Abstract There is a trend towards smaller and smaller structures (nanostructures/ miniaturization) which is well-known in microelectronic, energy and semiconductor applications. Nanoengineering is expected to lead to significant improvements in the intrinsic properties of structures, e. g., in energy storage for supercapacitors. In this context, a deeper understanding of the growth mechanisms of the thinnest crystal layers is of crucial importance for the controlled growing of nanowhiskers with outstanding properties. In the present study, we consider a simple whisker growth model based on the surface energy (i. e., wettability) of the components and investigate the effect of the carbon interlayer deposited on a Si (111) wafer using the magnetron sputtering technique on the whisker formation during the subsequent molecular beam epitaxy process in the Si-C-Cu system. In the present study, the topographic holes in the carbon layer which are the preferred nucleation areas of whiskers were identified by a series of scanning tunneling microscopy analyses, and the natural hole density was statistically determined. Using atomic force microscopy, the surface roughness of the carbon layer was characterized. The results of our investigations indicate that there is a correlation between the hole density in the carbon layer and the density of Cu nanowhiskers. This may validate the supposition that the holes in the carbon layer are the preferred nucleation sites for whiskers – an effect that could be relevant for future works on the growth of nanowhiskers at predefined positions.


Author(s):  
Caterina Soldano ◽  
Mark A. Ashworth ◽  
Geoffrey D. Wilcox ◽  
Terho Kutilainen ◽  
Jussi Hokka ◽  
...  

AbstractIn this study, we demonstrate how metal-oxide thin-film conformal coatings grown by atomic layer deposition (ALD) can be exploited as an effective approach to mitigate tin whisker growth on printed circuit boards. First, we study the effect of different ALD coatings and process parameters on Sn–Cu-electroplated test coupons, by combining optical imaging and scanning electron microscopy and evaluating whisker distribution on the surface. On these samples, we found that one important parameter in mitigating whisker growth is the time interval between electroplating and the ALD coating process (pre-coat time), which should be kept of the order of few days (2, based on our results). Atomic layer-deposited coatings were also found to be effective toward whisker formation in different storage conditions. Furthermore, we show that ALD coating is also effective in limiting the need for outgassing of electronic assemblies (PCBAs), which is an additional stringent requirement for applications in space industry. Our experimental results thus demonstrated that atomic layer deposition is a suitable technique for aerospace applications, both in terms of degassing and whisker mitigation.


Nanomaterials ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2429
Author(s):  
Gowtham Jawaharram ◽  
Christopher Barr ◽  
Khalid Hattar ◽  
Shen Dillon

A series of nanopillar compression tests were performed on tungsten as a function of temperature using in situ transmission electron microscopy with localized laser heating. Surface oxidation was observed to form on the pillars and grow in thickness with increasing temperature. Deformation between 850 °C and 1120 °C is facilitated by long-range diffusional transport from the tungsten pillar onto adjacent regions of the Y2O3-stabilized ZrO2 indenter. The constraint imposed by the surface oxidation is hypothesized to underly this mechanism for localized plasticity, which is generally the so-called whisker growth mechanism. The results are discussed in context of the tungsten fuzz growth mechanism in He plasma-facing environments. The two processes exhibit similar morphological features and the conditions under which fuzz evolves appear to satisfy the conditions necessary to induce whisker growth.


Author(s):  
Shuang Tian ◽  
Ruihua Cao ◽  
Qizhou Fan ◽  
Xingxing Zhou ◽  
Yongqiang Jia ◽  
...  

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1842
Author(s):  
Matic Jovičević-Klug ◽  
Patricia Jovičević-Klug ◽  
Tina Sever ◽  
Darja Feizpour ◽  
Bojan Podgornik

The elucidation of spontaneous growth of metal whiskers from metal surfaces is still ongoing, with the mainstream research conducted on Sn whiskers. This work reports on the discovery of Pb whisker growth from Bi-Mg-Pb solid pools found in common machinable aluminum alloy. The whiskers and hillocks display unique morphologies and complex growth that have not been documented beforehand. In contrast to typical understanding of whisker growth, the presented Pb whiskers show a clear nanocrystalline induced growth mechanism, which is a novel concept. Furthermore, the investigated whiskers are also found to be completely composed of nanocrystals throughout their entire length. The performed research gives new insight into nucleation and growth of metal whiskers, which raises new theoretical questions and challenges current theories of spontaneous metal whisker growth. Additionally, this work provides the first microscopic confirmation of recrystallization growth theory of whiskers that relates to oriented attachment of nanocrystals formed within an amorphous metallic matrix. The impact of mechanical stress, generated through Bi oxidation within the pools, is theoretically discussed with relation to the observed whisker and hillock growth. The newly discovered nanocrystalline growth provides a new step towards understanding spontaneous metal whisker growth and possibility of developing nanostructures for potential usage in sensing and electronics applications.


Author(s):  
Shuai Li ◽  
Yushuang Liu ◽  
Peigen Zhang ◽  
Yan Zhang ◽  
Chengjie Lu ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document