Impact of Ni concentration on the intermetallic compound formation and brittle fracture strength of Sn–Cu–Ni (SCN) lead-free solder joints

2014 ◽  
Vol 54 (2) ◽  
pp. 435-446 ◽  
Author(s):  
Chaoran Yang ◽  
Fubin Song ◽  
S.W. Ricky Lee
Keyword(s):  
Intermetallic Compound ◽  
Brittle Fracture ◽  
Fracture Strength ◽  
Solder Joints ◽  
Lead Free ◽  
Lead Free Solder ◽  
Compound Formation ◽  
Intermetallic Compound Formation ◽  
Free Solder

Intermetallic compound formation and mechanical property of Sn-Cu-xCr/Cu lead-free solder joint

2017 ◽  
Vol 728 ◽  
pp. 992-1001 ◽  
Author(s):  
Junghwan Bang ◽  
Dong-Yurl Yu ◽  
Yong-Ho Ko ◽  
Min-Su Kim ◽  
Hiroshi Nishikawa ◽  
...  
Keyword(s):  
Mechanical Property ◽  
Intermetallic Compound ◽  
Solder Joint ◽  
Lead Free ◽  
Lead Free Solder ◽  
Compound Formation ◽  
Intermetallic Compound Formation ◽  
Free Solder

Plastic Strain Distribution as a Precursor for Transition From Ductile to Brittle Failure in Lead-Free Solder Joints

2009 ◽  
Author(s):  
Feng Gao ◽  
Jianping Jing ◽  
Frank Z. Liang ◽  
Richard L. Williams ◽  
Jianmin Qu
Keyword(s):  
Brittle Fracture ◽  
Plastic Strain ◽  
Solder Joint ◽  
Failure Mode ◽  
Strain Distribution ◽  
Solder Joints ◽  
Lead Free ◽  
Lead Free Solder ◽  
Loading Rates ◽  
Free Solder

One of the major failure modes in lead-free solder joints is the brittle fracture at the solder/Cu pad interface under dynamic loading conditions. Such brittle fracture often leads to catastrophic premature failure of portable electronic devices. Therefore, it is desirable to design the package and the solder joints in such a way that brittle interfacial fracture can be avoided during drop test. To develop such design guidelines, we studied in this paper the dynamic failure of a single solder joint (SSJ). The SSJs with different geometry and substrate surface finish were prepared by laser-cutting from a BGA package assembled on a printed circuit board (PCB). The SSJs were tested under various shear loading rates, ranging from 5 mm/s to 500 mm/s. In conjunction with the experimental tests, finite element analyses (FEA) of these SSJ samples subjected to various loading rates were also conducted. Results from both experimental testing and numerical simulations show that the distribution of plastic strain near the solder/IMC interface is a key indictor of the failure mode. For a given sample geometry and loading rate, if the maximum solder plastic strain lies near the solder/IMC interface, the failure will be more likely to be ductile failure within the solder alloy. On the other hand, if the maximum plastic strain is mainly located at the edge of the interface between solder and the IMC layer with very little plasticity within the solder near the interface, brittle fracture of the IMC/Cu interface will be more likely to occur. Since numerically computing the plastic strain distribution in a solder joint is much easier than predicting joint failure, results of this study provide us with an effective means to predict the type of failure mode of a solder joint under dynamic loading.

Influence of Bi Addition on Wettability and Mechanical Properties of Sn-0.7Cu Solder Alloy

2018 ◽  
Vol 273 ◽  
pp. 27-33 ◽  
Author(s):  
Mohd Izrul Izwan Ramli ◽  
M.S.S. Yusof ◽  
Mohd Arif Anuar Mohd Salleh ◽  
Rita Mohd Said ◽  
Kazuhiro Nogita
Keyword(s):  
Mechanical Properties ◽  
Intermetallic Compound ◽  
Lead Free Solder ◽  
Compound Formation ◽  
Alloying Additions ◽  
Wetting Properties ◽  
Intermetallic Compound Formation ◽  
Interfacial Intermetallic Compound ◽  
Free Solder ◽  
Intermetallic Layers

The effect of bismuth (Bi) micro-alloying additions on wettability and mechanical properties of Sn-0.7Cu lead-free solder were explored. This paper also investigates the influences of various Bi percentages on the suppression of intermetallic compound formation. Scanning electron microscope (SEM) was used to observe the microstructure evolution of solder joint including the thickness of interfacial intermetallic layers. Overall, with the addition of Bi to Sn-0.7Cu solder, the size of primary Cu6Sn5become smaller and suppresses the thickness of interfacial intermetallic compound between solder and the Cu substrate. Microhardness value and wetting properties also increased with Bi addition which resulted in smaller size of β-Sn and Cu6Sn5.

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