Effect of Current Density on the Nucleation and Growth of Crystal Facets during Pulse Electrodeposition of Sn–Cu Lead-Free Solder

2014 ◽  
Vol 14 (12) ◽  
pp. 6542-6549 ◽  
Author(s):  
Manila Mallik ◽  
Arijit Mitra ◽  
Srijan Sengupta ◽  
Karabi Das ◽  
Rabindra N. Ghosh ◽  
...  
Keyword(s):  
Current Density ◽  
Nucleation And Growth ◽  
Pulse Electrodeposition ◽  
Lead Free ◽  
Lead Free Solder ◽  
Free Solder

Effects of high current density on lead-free solder joints of chip-size passive SMD components

2018 ◽  
Vol 30 (2) ◽  
pp. 74-80 ◽  
Author(s):  
Attila Geczy ◽  
Daniel Straubinger ◽  
Andras Kovacs ◽  
Oliver Krammer ◽  
Pavel Mach ◽  
...  
Keyword(s):  
Current Density ◽  
Solder Joints ◽  
High Current Density ◽  
Lead Free ◽  
Lead Free Solder ◽  
High Current ◽  
Chip Size ◽  
Free Solder

Effects of Current Stressing and Isothermal Aging on the Tensile Strength of Microscale Lead-Free Solder Joints with Different Joint Volumes

2013 ◽  
Vol 634-638 ◽  
pp. 2800-2803 ◽  
Author(s):  
Li Meng Yin ◽  
Yan Fei Geng ◽  
Zhang Liang Xu ◽  
Song Wei
Keyword(s):  
Tensile Strength ◽  
Current Density ◽  
Isothermal Aging ◽  
Solder Joints ◽  
High Current Density ◽  
Copper Wire ◽  
Lead Free ◽  
Lead Free Solder ◽  
Current Stressing ◽  
Free Solder

Adopting an accurate micro-tensile method based on dynamic mechanical analyzer (DMA) instrument, the tensile strength of three kinds of copper-wire/solder/copper-wire sandwich structured microscale lead-free solder joints that underwent current stressing with a direct current density of 1.0×104 A/cm2 and loading time of 48 hours were investigated, and compared with those solder joints isothermal aged at 100 0C for 48 hours and as-reflowed condition. These three kinds of microscale columnar solder joints have different volumes, i.e., a same diameter of 300 μm but different heights of 100 μm, 200 μm and 300 μm. Experimental results show that both current stressing and isothermal aging degrades the tensile strength of microscale solder joints, and the solder joint with smaller volume obtains higher tensile strength under same test condition. In addition, current stressing induces obvious electromigration (EM) issue under high current density of 1.0×104 A/cm2, resulting in the decreasing of tensile strength and different fracture position, mode and surface morphology of microscale solder joints. The degree of strength degradation increases with the increasing of joint height when keep joint diameter constant, this is mainly due to that electromigration leads to voids form and grow at the interface of cathode, and solder joints with larger volume may contains more soldering defects as well.

Advances on high current load effects on lead-free solder joints of SMD chip-size components and BGAs

Circuit World ◽  
2019 ◽  
Vol 45 (1) ◽  
pp. 37-44
Author(s):  
Dániel Straubinger ◽  
Attila Géczy ◽  
András Sipos ◽  
András Kiss ◽  
Dániel Gyarmati ◽  
...  
Keyword(s):  
Current Density ◽  
Solder Joints ◽  
Lead Free ◽  
Lead Free Solder ◽  
High Current ◽  
Current Load ◽  
Content Type ◽  
Chip Size ◽  
Free Solder ◽  
Current Loading

Purpose This paper aims to present a novel approach on investigating critical current densities in the solder joints of chip-size surface-mounted components or device (SMD) components and ball grid array (BGA) lead-free solder joints with the focus of via-in-pad geometries. The investigation involves a numerical approach and a physical validation with selected geometry configurations and high current loads to reveal possible failure sources. The work is a continuation of a previous study. Design/methodology/approach Current density was investigated using finite element modeling on BGA joints. Dummy BGA components, 0402 and 0603 zero ohm jumper resistors, were used, both in daisy chain setups on standard FR4 printed circuit boards (PCBs). Respective physical loading experiments were set to find effects of elevated current density at hot zones of the joints. Cross-section analysis, scanning electron microscopy and shear force tests were used to analyze the joints. Findings The findings reveal alterations in the joints, while the current loading is not directly affecting the structure. The modeling reveals the current density map in the selected formations with increased current crowding zones. Overall, the degradation does not reach the level of electromigration (EM)-induced voiding due to the limiting factor of the FR4 substrate. Practical implications The heavy current load affects joint reliability, but there are limitations of EM-induced failures on PCB-based assemblies due to the thermomechanical weakness of the FR4 material. Originality/value The experiments investigate current density from a novel aspect on frequently used BGA surface mounted components with modeling configurations focusing on possible effects of via-in-pad structure.

Nucleation and Growth of Cu-Al Intermetallics in Al-Modified Sn-Cu and Sn-Ag-Cu Lead-Free Solder Alloys

2015 ◽  
Vol 44 (3) ◽  
pp. 842-866 ◽  
Author(s):  
Kathlene N. Reeve ◽  
Iver E. Anderson ◽  
Carol A. Handwerker
Keyword(s):  
Nucleation And Growth ◽  
Lead Free ◽  
Lead Free Solder ◽  
Solder Alloys ◽  
Free Solder

Effect of aluminum content on structure, transport and mechanical properties of Sn-Zn eutectic lead free solder alloy rapidly solidified from melt.

2015 ◽  
Vol 10 (1) ◽  
pp. 2641-2648
Author(s):  
Rizk Mostafa Shalaby ◽  
Mohamed Munther ◽  
Abu-Bakr Al-Bidawi ◽  
Mustafa Kamal
Keyword(s):  
Mechanical Properties ◽  
Melting Point ◽  
Lead Free ◽  
Al Alloy ◽  
Lead Free Solder ◽  
Pronounced Increase ◽  
Mass Unit ◽  
Size Refinement ◽  
Free Solder ◽  
Lead Free Solders

The greatest advantage of Sn-Zn eutectic is its low melting point (198 oC) which is close to the melting point. of Sn-Pb eutectic solder (183 oC), as well as its low price per mass unit compared with Sn-Ag and Sn-Ag-Cu solders. In this paper, the effect of 0.0, 1.0, 2.0, 3.0, 4.0, and 5.0 wt. % Al as ternary additions on melting temperature, microstructure, microhardness and mechanical properties of the Sn-9Zn lead-free solders were investigated. It is shown that the alloying additions of Al at 4 wt. % to the Sn-Zn binary system lead to lower of the melting point to 195.72 ˚C.  From x-ray diffraction analysis, an aluminium phase, designated α-Al is detected for 4 and 5 wt. % Al compositions. The formation of an aluminium phase causes a pronounced increase in the electrical resistivity and microhardness. The ternary Sn-9Zn-2 wt.%Al exhibits micro hardness superior to Sn-9Zn binary alloy. The better Vickers hardness and melting points of the ternary alloy is attributed to solid solution effect, grain size refinement and precipitation of Al and Zn in the Sn matrix.  The Sn-9%Zn-4%Al alloy is a lead-free solder designed for possible drop-in replacement of Pb-Sn solders.  

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