scholarly journals Introductory Chapter: Overview of Pb-Free Solders and Effect of Multilayered Thin Film of Sn on the Lead-Free Solder Joint Interface

2019 ◽  
Author(s):  
Monalisa Char ◽  
Abhijit Kar
Keyword(s):  
Thin Film ◽  
Solder Joint ◽  
Lead Free ◽  
Joint Interface ◽  
Lead Free Solder ◽  
Multilayered Thin Film ◽  
Free Solder

Effect of Cooling Rate on Intermetallic Compounds Formation in Sn-Ag-Cu-In Solder

2018 ◽  
Vol 941 ◽  
pp. 2075-2080
Author(s):  
Kenji Miki ◽  
Tatsuya Kobayashi ◽  
Ikuo Shohji ◽  
Yusuke Nakata
Keyword(s):  
Solder Joint ◽  
Cooling Rate ◽  
Shear Force ◽  
Bonding Temperature ◽  
Lead Free ◽  
Joint Interface ◽  
Lead Free Solder ◽  
Vacuum Atmosphere ◽  
Free Solder ◽  
Large Formation

The effect of the cooling rate in bonding on IMCs formation and their morphology in the solder joint with Sn-3.0Ag-0.7Cu-5.0In (mass%) lead-free solder was investigated. As the substrate, the Cu plate and the Cu plate with electroplated Ni were prepared. Bonding was conducted in the vacuum atmosphere, and bonding temperature and time were 300°C and 10 minutes, respectively. The cooling rates in the bonding were changed from 0.02°C/s to 0.2°C/s. In both Cu/Cu and Cu/Ni joints, scallop-shaped IMCs form at the joint interfaces regardless of the cooling rate. In the Cu/Cu joint, Cu6(Sn,In)5 and Cu3(Sn,In) layers form at the joint interface. In the Cu/Ni joint, (Cu,Ni)6(Sn,In)5 and (Cu,Ni)3(Sn,In) layers form at the joint interface with Cu and the (Cu,Ni)6(Sn,In)5 layer forms at the joint interface with Ni. Die shear force of the Cu/Ni joints are a little larger than those of the Cu/Cu joints. Fracture occurs in the boundary between the scallop-shaped layer or the granular IMC layer and the layered IMC in both joints. The cooling rate from the peak temperature to solidification is an important factor to decide the shape of formed IMC. When the cooling rate is high and supercooling becomes large, formation of pillar-shaped IMCs occurs easily.

Study on the Mechanical Bend Fatigue of Micro-Joining Soldered Joint with Lead-Free Solder

2007 ◽  
Vol 353-358 ◽  
pp. 2573-2576 ◽  
Author(s):  
Fang Juan Qi ◽  
Li Xing Huo ◽  
Ya Ping Ding ◽  
Zhan Lai Ding
Keyword(s):  
Solder Joint ◽  
Failure Modes ◽  
Lead Free ◽  
Joint Interface ◽  
Similar Data ◽  
Lead Free Solder ◽  
Fatigue Reliability ◽  
Free Solder ◽  
Halogen Free ◽  
Soldered Joint

In recent years, several electronics manufacturers have been working toward introducing lead-free solder and halogen-free print circuit boards (PCBs) into their products. The key drivers for the change in materials have been the impending environmental legislations, particularly in Europe and Japan as well as the market appeal of ‘green’ products. The reliability of the new materials is an important determinant of the pace of adoption. Fairly extensive mechanical fatigue reliability data is also available for micro-joining soldered joint such as Ball Grid Array (BGA) with tin-lead solder. However, similar data is not available for BGAs assembled with lead-free solder. Mechanical reliability is a critical indicator for phone and BGA survival during repeated keypress, and to some extent during drop. In this paper, the mechanical bend fatigue of BGAs with tin-lead and lead-free solders on halogen-free substrates are examined respectively. A tin-silver-copper alloy was used as lead-free solder due to its increasing acceptance, and the results were compared to those from samples assembled with Sn63Pb37 solder. The reliability was examined at both low cycle and high cycle fatigue. Results show that the mechanical bend fatigue reliability of BGA assemblies with lead-free solder is higher than that of BGA assembly with tin-lead solder. Cross section and failure analysis indicated two distinct failure modes - solder joint and PCB failure. A 3-D parametric finite element model was developed to correlate the local PCB strains and solder joint plastic strains with the fatigue life of the assembly. The intermetallic compoumd (IMC) of micro-joining joint interface was analysised in the future in order to study on the effect of IMC on the reliability.

Effect of Added Elements on Microstructures and Joint Strength of Lead-Free Sn-Based Solder Joint Dispersed IMC Pillar

2016 ◽  
Vol 879 ◽  
pp. 2216-2221 ◽  
Author(s):  
Yawara Hayashi ◽  
Ikuo Shohji ◽  
Yusuke Nakata ◽  
Tomihito Hashimoto
Keyword(s):  
Solder Joint ◽  
Shear Force ◽  
Joint Strength ◽  
High Reliability ◽  
Bonding Time ◽  
Lead Free ◽  
Joint Interface ◽  
Lead Free Solder ◽  
Uniform Dispersion ◽  
Free Solder

To create a high reliability solder joint using IMCs dispersed in the joint, the joints with four types of lead-free solder were investigated. The joint with Sn-3.0Ag-0.7Cu-5.0In (mass%) has high die shear force compared to other joints investigated, and the joint with the Ni-electroplated Cu bonded at 300 oC for 30 min showed the maximum die shear force due to formation of a large number of fine IMCs. In the joint with Sn-0.7Cu-0.05Ni (mass%), uniform dispersion of a large number of IMCs was achieved, although the die shear force of the joint is lower than that of the joint with Sn-3.0Ag-0.7Cu-5.0In. In the joint with Sn-5.0Sb (mass%), a solder area was remained in the center of the joint although a large number of columnar IMCs form at the joint interface. The die shear force of the joint with Sn-5.0Sb increased with increasing the bonding time due to formation and growth of IMCs. In the joint with Sn-3.0Ag-0.5Cu (mass%), IMCs formed at the joint interface and did not disperse in the entire joint.

Impact reliability estimation of lead free solder joint with IMC layer

2009 ◽  
Vol 517 (14) ◽  
pp. 4255-4259 ◽  
Author(s):  
Jong-Min Kim ◽  
Seung-Wan Woo ◽  
Yoon-Suk Chang ◽  
Young-Jin Kim ◽  
Jae-Boong Choi ◽  
...  
Keyword(s):  
Solder Joint ◽  
Reliability Estimation ◽  
Lead Free ◽  
Lead Free Solder ◽  
Free Solder ◽  
Impact Reliability

Root Cause Investigation of Lead-Free Solder Joint Interfacial Failures After Multiple Reflows

2016 ◽  
Vol 46 (3) ◽  
pp. 1674-1682 ◽  
Author(s):  
Yan Li ◽  
Olen Hatch ◽  
Pilin Liu ◽  
Deepak Goyal
Keyword(s):  
Solder Joint ◽  
Lead Free ◽  
Lead Free Solder ◽  
Root Cause ◽  
Free Solder

Effect of Thickness of Pd Plating Layer on Shear Strength of Lead-Free Solder Ball Joint With Electroless Ni/Pd/Au Plated Electrode

2011 ◽  
Author(s):  
Takahiro Kano ◽  
Ikuo Shohji ◽  
Tetsuyuki Tsuchida ◽  
Toshikazu Ookubo
Keyword(s):  
Reaction Layer ◽  
Shear Force ◽  
Solder Ball ◽  
Lead Free ◽  
Joint Interface ◽  
Lead Free Solder ◽  
Solder Balls ◽  
Free Solder ◽  
Ball Joints ◽  
Electroless Ni

An electroless Ni/Pd/Au plated electrode is expected to be used as an electrode material for lead-free solder to improve joint reliability. The aim of this study is to investigate the effect of the thickness of the Pd layer on joint properties of the lead-free solder joint with the electroless Ni/Pd/Au plated electrode. Solder ball joints were fabricated with Sn-3Ag-0.5Cu (mass%) lead-free solder balls and electroless Ni/Pd/Au and Ni/Au plated electrodes. Ball shear force and microstructure of the joint were investigated. The (Cu,Ni)6Sn5 reaction layer formed in the joint interface in all specimens. The thickness of the reaction layer decreased with increasing the thickness of the Pd layer. In the joint with a Pd layer 0.36 μm thick, the remained Pd layer was observed in the joint interface. In the joint, impact shear force decreased compared with that of the joint without the remained Pd layer. On the contrary, when the thickness of the Pd layer was less than 0.36 μm, the Pd layer was not remained in the joint interface and impact shear force improved. Impact shear force of the joint with the electroless Ni/Pd/Au plated electrode was higher than that with the electroless Ni/Au one.

Study on High Reliability of Lead-Free Solder Joint on Metal Substrate

2011 ◽  
Author(s):  
Kanji Takagi ◽  
Masaki Wakabayashi ◽  
Junichi Inoue ◽  
Qiang Yu ◽  
Takahiro Akutsu
Keyword(s):  
Thermal Conductivity ◽  
Solder Joint ◽  
Rupture Life ◽  
Metal Substrate ◽  
Lead Free ◽  
Lead Free Solder ◽  
Insulating Layer ◽  
Heating Device ◽  
Propagation Analysis ◽  
Free Solder

This paper proposes the high reliable design method for lead-free solder joint on metal substrate on chip component. First, the crack propagation analysis method for estimating rupture life of solder joint was constructed. And then, the effect of material properties of insulating layer on metal substrate and solder joint shape for rupture life of solder joint was evaluated using crack propagation analysis. As the result, the relation between young’s modulus of insulating layer and rupture life was indicated quantitatively. Also, the relation of filet length for rupture life of solder joint was evaluated. Secondary, evaluation method of heat dissipation for metal substrate was proposed. Because thermal conductivity of insulating layer affects temperature rise of heating device. And, the relation between thermal conductivity of insulating layer and temperature rise of heating device was indicated.

Vibration Fatigue Reliability of Lead and Lead-Free Solder Joint by FORM/SORM

2007 ◽  
Vol 345-346 ◽  
pp. 1393-1396
Author(s):  
Ouk Sub Lee ◽  
Man Jae Hur ◽  
Yeon Chang Park ◽  
Dong Hyeok Kim
Keyword(s):  
Solder Joint ◽  
Failure Probability ◽  
Lead Free ◽  
Lead Free Solder ◽  
Fatigue Reliability ◽  
Probability Models ◽  
First Order ◽  
Reliability Method ◽  
Vibration Fatigue ◽  
Free Solder

It is well-known that the vibration significantly affect the life of solder joint. In this paper, the effects of the vibration on the failure probability of the solder joint are studied by using the failure probability models such as the First Order Reliability Method (FORM) and the Second Order Reliability Method (SORM). The accuracies of the results are estimated by a help of the Monte Carlo Simulation (MCS). The reliability of the lead and the lead-free solder joint was also evaluated. The reliability of lead-free solder joint is found to be higher than that of lead solder joint.

Solder Joint Reliability of Sn-Cu and Sn-Ag-Cu Lead-Free Solder Alloys Solidified on Copper Substrates with Different Surface Roughnesses

2015 ◽  
Vol 830-831 ◽  
pp. 265-269
Author(s):  
Satyanarayan ◽  
K.N. Prabhu
Keyword(s):  
Solder Joint ◽  
Solder Matrix ◽  
Lead Free ◽  
Lead Free Solder ◽  
Solder Alloys ◽  
Cu Substrate ◽  
Cu Substrates ◽  
Free Solder ◽  
Substrate Surfaces ◽  
Lead Free Solders

In the present work, the bond strength of Sn-0.7Cu, Sn-0.3Ag-0.7Cu, Sn-2.5Ag-0.5Cu and Sn-3Ag-0.5Cu lead free solders solidified on Cu substrates was experimentally determined. The bond shear test was used to assess the integrity of Sn–Cu and Sn–Ag–Cu lead-free solder alloy drops solidified on smooth and rough Cu substrate surfaces. The increase in the surface roughness of Cu substrates improved the wettability of solders. The wettability was not affected by the Ag content of solders. Solder bonds on smooth surfaces yielded higher shear strength compared to rough surfaces. Fractured surfaces revealed the occurrence of ductile mode of failure on smooth Cu surfaces and a transition ridge on rough Cu surfaces. Though rough Cu substrate improved the wettability of solder alloys, solder bonds were sheared at a lower force leading to decreased shear energy density compared to the smooth Cu surface. A smooth surface finish and the presence of minor amounts of Ag in the alloy improved the integrity of the solder joint. Smoother surface is preferable as it favors failure in the solder matrix.

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