The fractal nature analysis by applying grain formations of SAC305/OSP Cu and SAC305-0.05Ni/OSP Cu solder joints for microelectronic packaging

Author(s):  
Vojislav V. Mitić ◽  
Collin Fleshman ◽  
Jenq-Gong Duh ◽  
Ivana D. Ilić ◽  
Goran Lazović

The electronic packaging and systems are very important topics as the limitation of miniaturization approaches in semiconductor industry. Regarding the optimal materials microstructure for these applications, we studied different alloys such as Sn-3.0Ag-0.5Cu (wt.%)/organic solderability preservative (SAC305/OSP) Cu and SAC305–0.05Ni/OSP Cu solder joints. We implemented the fractal dimension characterization and microstructure morphology reconstruction. This is the first time that we applied fractals on such alloys. The morphology reconstruction is important for predicting and designing the optimal microstructure for the advanced desirable properties these alloys. These analyzed parameters are important for the hand-held devices and systems especially for the exploitation. The fractal reconstruction was applied on the prepared microstructures with five different magnifications. The results confirmed successful application of fractals in this area of materials science considering the grains and shapes reconstructions.

2018 ◽  
Vol 30 (1) ◽  
pp. 14-25 ◽  
Author(s):  
Peng Yao ◽  
Xiaoyan Li ◽  
Fengyang Jin ◽  
Yang Li

Purpose This paper aims to analyze the morphology transformation on the Cu3Sn grains during the formation of full Cu3Sn solder joints in electronic packaging. Design/methodology/approach Because of the infeasibility of analyzing the morphology transformation intuitively, a novel equivalent method is used. The morphology transformation on the Cu3Sn grains, during the formation of full Cu3Sn solder joints, is regarded as equivalent to the morphology transformation on the Cu3Sn grains derived from the Cu/Sn structures with different Sn thickness. Findings During soldering, the Cu3Sn grains first grew in the fine equiaxial shape in a ripening process until the critical size. Under the critical size, the Cu3Sn grains were changed from the equiaxial shape to the columnar shape. Moreover, the columnar Cu3Sn grains could be divided into different clusters with different growth directions. With the proceeding of soldering, the columnar Cu3Sn grains continued to grow in a feather of the width growing at a greater extent than the length. With the growth of the columnar Cu3Sn grains, adjacent Cu3Sn grains, within each cluster, merged with each other. Next, the merged columnar Cu3Sn grains, within each cluster, continued to merge with each other. Finally, the columnar Cu3Sn grains, within each cluster, merged into one coarse columnar Cu3Sn grain with the formation of full Cu3Sn solder joints. The detailed mechanism, for the very interesting morphology transformation, has been proposed. Originality/value Few researchers focused on the morphology transformation of interfacial phases during the formation of full intermetallic compounds joints. To bridge the research gap, the morphology transformation on the Cu3Sn grains during the formation of full Cu3Sn solder joints has been studied for the first time.


1999 ◽  
Vol 5 (S2) ◽  
pp. 870-871
Author(s):  
G. Ghosh

In electronic packaging, it is very important to understand and control the interfacial microstructure formed due to the reaction between the metallization scheme and solders. Often, the interfacial reaction is exploited/controlled to obtain an optimum properties of the joints. The strength and interfacial properties of the solder joints are determined by the interfacial microstructure. The evolution of interfacial microstructure in solder joints is governed by the diffusion path during processing and in service. Even though the semiconductor industry uses a wide variety of complex metallization schemes, recently the Pd-Ni metallization scheme on Cu has gained a lot of interest. Furthermore, the design of new metallization scheme(s) to control the interfacial microstructure and to improve the quality of solder joints is the cornerstone of advanced electronic packaging. We have carried out a systematic study of diffusion and interfacial reaction, both in the liquid and solid states, between Pb-Sn eutectic solder and the Pd-Ni metallization scheme on Cu.


Author(s):  
M. Rühle ◽  
J. Mayer ◽  
J.C.H. Spence ◽  
J. Bihr ◽  
W. Probst ◽  
...  

A new Zeiss TEM with an imaging Omega filter is a fully digitized, side-entry, 120 kV TEM/STEM instrument for materials science. The machine possesses an Omega magnetic imaging energy filter (see Fig. 1) placed between the third and fourth projector lens. Lanio designed the filter and a prototype was built at the Fritz-Haber-Institut in Berlin, Germany. The imaging magnetic filter allows energy-filtered images or diffraction patterns to be recorded without scanning using efficient area detection. The energy dispersion at the exit slit (Fig. 1) results in ∼ 1.5 μm/eV which allows imaging with energy windows of ≤ 10 eV. The smallest probe size of the microscope is 1.6 nm and the Koehler illumination system is used for the first time in a TEM. Serial recording of EELS spectra with a resolution < 1 eV is possible. The digital control allows X,Y,Z coordinates and tilt settings to be stored and later recalled.


2018 ◽  
Author(s):  
Satish Kodali ◽  
Liangshan Chen ◽  
Yuting Wei ◽  
Tanya Schaeffer ◽  
Chong Khiam Oh

Abstract Optical beam induced resistance change (OBIRCH) is a very well-adapted technique for static fault isolation in the semiconductor industry. Novel low current OBIRCH amplifier is used to facilitate safe test condition requirements for advanced nodes. This paper shows the differences between the earlier and novel generation OBIRCH amplifiers. Ring oscillator high standby leakage samples are analyzed using the novel generation amplifier. High signal to noise ratio at applied low bias and current levels on device under test are shown on various samples. Further, a metric to demonstrate the SNR to device performance is also discussed. OBIRCH analysis is performed on all the three samples for nanoprobing of, and physical characterization on, the leakage. The resulting spots were calibrated and classified. It is noted that the calibration metric can be successfully used for the first time to estimate the relative threshold voltage of individual transistors in advanced process nodes.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hyeon-Myeong Oh ◽  
Young-Jo Park ◽  
Ha-Neul Kim ◽  
Kundan Kumar ◽  
Jae-Woong Ko ◽  
...  

AbstractMotivated by recent finding of crystallographic-orientation-dependent etching behavior of sintered ceramics, the plasma resistance of nanocrystalline Y2O3-MgO composite ceramics (YM) was evaluated for the first time. We report a remarkably high plasma etching resistance of nanostructure YM surpassing the plasma resistance of commercially used transparent Y2O3 and MgAl2O4 ceramics. The pore-free YM ceramic with grain sizes of several hundred nm was fabricated by hot press sintering, enabling theoretical maximum densification at low temperature. The insoluble two components effectively suppressed the grain growth by mutual pinning. The engineering implication of the developed YM nanocomposite imparts enhanced mechanical reliability, better cost effectiveness with excellent plasma resistance property over their counterparts in plasma using semiconductor applications.


2000 ◽  
Vol 6 (S2) ◽  
pp. 524-525 ◽  
Author(s):  
Michael W. Phaneuf ◽  
Jian Li

Focused ion beam (FIB) microscopes, the use of which is well established in the semiconductor industry, are rapidly gaining attention in the field of materials science, both as a tool for producing site specific, parallel sided TEM specimens and as a stand alone specimen preparation and imaging tool.Both FIB secondary ion images (FIB SII) and FIB secondary electron images (FIB SEI) contain novel crystallographic and chemical information. The ability to see “orientation contrast” in FIB SEI and to a lesser extent SII is well known for cubic materials and more recently stress-free FIB sectioning combined with FIB imaging have been shown to reveal evidence of plastic deformation in metallic specimens. Particularly in hexagonal metals, FIB orientation contrast is sometimes reduced or eliminated by the FIB sectioning process. We have successfully employed FIB gas assisted etching during FIB sectioning using XeF2 for zirconium alloys and Cl2 for zinc coatings on steels to retain orientation contrast during subsequent imaging.


2020 ◽  
Author(s):  
Jin Soo Lim ◽  
Jonathan Vandermause ◽  
Matthijs A. van Spronsen ◽  
Albert Musaelian ◽  
Yu Xie ◽  
...  

Restructuring of interfaces plays a crucial role in materials science and heterogeneous catalysis. Bimetallic systems, in particular, often adopt very different composition and morphology at surfaces compared to the bulk. For the first time, we reveal a detailed atomistic picture of long-timescale restructuring of Pd deposited on Ag, using microscopy, spectroscopy, and novel simulation methods. By developing and performing accelerated machine-learning molecular dynamics followed by an automated analysis method, we discover and characterize previously unidentified surface restructuring mechanisms in an unbiased fashion, including Pd-Ag place exchange and Ag pop-out, as well as step ascent and descent. Remarkably, layer-by-layer dissolution of Pd into Ag is always preceded by an encapsulation of Pd islands by Ag, resulting in a significant migration of Ag out of the surface and a formation of extensive vacancy pits within a period of microseconds. These metastable structures are of vital catalytic importance, as Ag-encapsulated Pd remains much more accessible to reactants than bulk-dissolved Pd. Our approach is broadly applicable to complex multimetallic systems and enables the previously intractable mechanistic investigation of restructuring dynamics at atomic resolution.


2021 ◽  
pp. 2150318
Author(s):  
Vojislav V. Mitić ◽  
Po-Yu Chen ◽  
Yueh-Ying Chou ◽  
Ivana D. Ilić ◽  
Bojana Marković ◽  
...  

Hydroxyapatite scaffold is a type of bio-ceramic. Its cellular design has similarities with the morphologies in nature. Therefore, it is very important to control the structure, especially the porosity, as one of the main features for bio-ceramics applications. According to some literature, freeze casting can form the shape of dendrites and remain a foam structure after ice sublimation. Ice nucleation became more heterogeneous with the aid of printing materials during freeze casting. This procedure can even improve the issue of crack formation. In this paper, we studied the mechanical properties of hydroxyapatite scaffold. We also analyzed the porosity by fractal nature characterization, and successfully reconstructed pore shape, which is important for predicting ceramic morphology. We applied SEM analysis on bio-ceramic samples, at four different magnifications for the same pore structure. This is important for fractal analysis and pores reconstruction. We calculated the fractal dimensions based on measurements. In this way, we completed the fractal characterization of porosity and confirmed possibilities for successful porous shapes reconstruction. In this paper, we confirmed, for the first time, that fractal nature can be successfully applied in the area of porous bio-ceramics.


Sign in / Sign up

Export Citation Format

Share Document