Interfacial Reaction and Shear Strength of Pb-Free Sn-3.5Ag/Ni BGA Solder Joints during Reflow

2005 ◽  
Vol 486-487 ◽  
pp. 289-292 ◽  
Author(s):  
Jeong Won Yoon ◽  
Sang Won Kim ◽  
Seung Boo Jung
Keyword(s):  
Shear Strength ◽  
Intermetallic Compound ◽  
Interfacial Reaction ◽  
Solder Joints ◽  
The Other ◽  
Reflow Time ◽  
Ni Substrate ◽  
Other Hand

The interfacial reaction between eutectic Sn-3.5wt.%Ag solder and Ni substrate resulted in the formation of Ni3Sn4 intermetallic compound (IMC) layer. After formation of the Ni3Sn4 IMC, its grain coarsened and faceted continuously in a prolonged reflow reaction. The thickness of the IMC layer increased with reflow time. On the other hand, the brittleness of the joints increased with increasing reflow time, and the fracture occurred at the interface. The deterioration of the shear strength was found to be predominantly caused by the formation of the thick Ni3Sn4 IMC layer.

Interfacial Reaction of Cu/Sn-Ag/ENIG Sandwich Solder Joint during Aging

2006 ◽  
Vol 15-17 ◽  
pp. 1001-1007 ◽  
Author(s):  
Jeong Won Yoon ◽  
Seung Boo Jung
Keyword(s):  
Intermetallic Compound ◽  
Solder Joint ◽  
Interfacial Reaction ◽  
Isothermal Aging ◽  
Aging Treatment ◽  
Interfacial Reactions ◽  
The Other ◽  
Other Hand ◽  
Electroless Ni ◽  
Isothermal Aging Treatment

The interaction between Cu/Sn-Ag and Sn-Ag/Ni interfacial reactions has been studied during isothermal aging at 150°C for up to 1000h using a Cu/Sn-3.5Ag/ENIG sandwich solder joint. A typical scallop-type Cu-Sn intermetallic compound (IMC) layer formed at the upper Sn-Ag/Cu interface after reflowing. On the other hand, a (Cu,Ni)6Sn5 IMC layer was observed at the Sn-Ag/ENIG interface. The Cu in the (Cu,Ni)6Sn5 IMC layer formed on the Ni side has to be contributed from the dissolution of the opposite Cu metal pad or Cu-Sn IMC layer. When the dissolved Cu arrived at the interface of the Ni pad, the (Cu,Ni)6Sn5 IMC layer formed on the Ni interface, preventing the Ni pad from reacting with the solder. Although a long isothermal aging treatment at 150°C was performed, any Ni was not detected in the Cu-Sn IMC layer formed on the Cu side. Compared to the single Sn-Ag/ENIG solder joint, the formation of the (Cu,Ni)6Sn5 IMC layer of the Cu/Sn-Ag/ENIG sandwich joint retarded effectively the consumption of the Ni from the electroless Ni-P layer.

Interfacial reactions and shear strength on Cu and electrolytic Au/Ni metallization with Sn-Zn solder

2006 ◽  
Vol 21 (6) ◽  
pp. 1590-1599 ◽  
Author(s):  
Jeong-Won Yoon ◽  
Seung-Boo Jung
Keyword(s):  
Thermal Expansion ◽  
Shear Strength ◽  
Intermetallic Compound ◽  
Aging Time ◽  
Interfacial Reaction ◽  
Joint Strength ◽  
Ball Grid Array ◽  
Fast Reaction ◽  
Cu Substrate ◽  
Ni Substrate

The interfacial reaction between eutectic Sn-9 wt% Zn solder and two different kinds of ball-grid-array substrates (Cu and Au/Ni electroplated Cu) during aging at 150 °C and the shear strength of the resulting joints were investigated. In the Sn-9Zn/Cu joints, only Cu5Zn8 intermetallic compound (IMC) was observed between the solder and Cu layer during the first 100 h of aging. After aging for 1000 h, the layer-type Cu5Zn8 IMC layer was disrupted at the interface, causing it to act as a channel for the diffusion of Sn. As a result, Cu6Sn5 and Cu3Sn IMCs were formed underneath the Cu5Zn8 IMC layer. This interfacial reaction significantly degraded the joint strength. In the case of the Au/Ni/Cu substrate, an AuZn3 IMC layer formed at the interface because of the fast reaction between Au and Zn. In addition, the AuZn3 IMC layer became detached from the interface during reflow. The detachment of the AuZn3 IMC layer is presumably from the mismatch in the coefficients of thermal expansion and weak adhesion between the AuZn3 IMC layer and Ni layer caused by the depletion of the Au layer. When the aging time was extended to 100 h, Ni5Zn21 IMC was observed on the Ni substrate. The shear strength of the aged Sn-9Zn/Au/Ni/Cu joint was significantly related to the detachment of the AuZn3 IMC layer. After aging at 150 °C, fracturing occurred on the detached AuZn3 IMC layer. To ensure the reliability of the Sn-Zn/Au/Ni/Cu joint, the detachment of the AuZn3 IMC needs to be prevented.

Interfacial Reaction of Electroless Ni-P Plating with Sn-3.5Ag (-Co) Solder

2008 ◽  
Vol 580-582 ◽  
pp. 243-246 ◽  
Author(s):  
Hiroshi Nishikawa ◽  
Akira Komatsu ◽  
Tadashi Takemoto
Keyword(s):  
Intermetallic Compound ◽  
Interfacial Reaction ◽  
Fracture Mode ◽  
Joint Strength ◽  
Solder Bump ◽  
Solder Joints ◽  
Pull Strength ◽  
Electroless Ni

The reaction between Sn-Ag (-Co) solder and electroless Ni-P plating was investigated in order to clarify the effect of the addition of Co to Sn-Ag solder on the formation of intermetallic compound (IMC) at the interface and the joint strength at the interface. Sn-Ag-Co solder was specially prepared. The results show that there is little effect of the addition of Co to the Sn-Ag solder on the IMC formation and the thickness of the IMC at the interface. For the pull strength of the solder bump joint, the addition of Co to the solder didn’t strongly affect the pull strength of the solder joints, but it affected the fracture mode of the solder joints.

Effect of intermetallic compound layer thickness on the shear strength of 1206 chip resistor solder joint

2015 ◽  
Vol 27 (1) ◽  
pp. 52-58 ◽  
Author(s):  
Peter K. Bernasko ◽  
Sabuj Mallik ◽  
G. Takyi
Keyword(s):  
Shear Strength ◽  
Intermetallic Compound ◽  
Solder Joint ◽  
Layer Thickness ◽  
Solder Joints ◽  
Ageing Time ◽  
Circuit Board ◽  
Intermetallic Compound Layer ◽  
Content Type ◽  
Surface Mount

Purpose – The purpose of this paper is to study the effect of intermetallic compound (IMC) layer thickness on the shear strength of surface-mount component 1206 chip resistor solder joints. Design/methodology/approach – To evaluate the shear strength and IMC thickness of the 1206 chip resistor solder joints, the test vehicles were conventionally reflowed for 480 seconds at a peak temperature of 240°C at different isothermal ageing times of 100, 200 and 300 hours. A cross-sectional study was conducted on the reflowed and aged 1206 chip resistor solder joints. The shear strength of the solder joints aged at 100, 200 and 300 hours was measured using a shear tester (Dage-4000PXY bond tester). Findings – It was found that the growth of IMC layer thickness increases as the ageing time increases at a constant temperature of 175°C, which resulted in a reduction of solder joint strength due to its brittle nature. It was also found that the shear strength of the reflowed 1206 chip resistor solder joint was higher than the aged joints. Moreover, it was revealed that the shear strength of the 1206 resistor solder joints aged at 100, 200 and 300 hours was influenced by the ageing reaction times. The results also indicate that an increase in ageing time and temperature does not have much influence on the formation and growth of Kirkendall voids. Research limitations/implications – A proper correlation between shear strength and fracture mode is required. Practical implications – The IMC thickness can be used to predict the shear strength of the component/printed circuit board pad solder joint. Originality/value – The shear strength of the 1206 chip resistor solder joint is a function of ageing time and temperature (°C). Therefore, it is vital to consider the shear strength of the surface-mount chip component in high-temperature electronics.

Effect of Sb Addition on Microstructure and Shear Strength of Sn-Ag Solder Joints

2004 ◽  
Vol 261-263 ◽  
pp. 501-506 ◽  
Author(s):  
H.T. Lee ◽  
C.L. Yang ◽  
Ming He Chen ◽  
C.S. Li
Keyword(s):  
Mechanical Properties ◽  
Growth Rate ◽  
Shear Strength ◽  
Intermetallic Compound ◽  
Solder Joints ◽  
Thermal Storage ◽  
Experimental Results ◽  
Storage Test ◽  
Ag3sn Phase ◽  
Epma Analysis

The effect of Sb addition on microstructure, intermetallic compound (IMC) and mechanical properties of Sn-Ag solder joints is investigated. The compositions of selected solders are Sn2.58Ag, Sn2.82Ag1.75Sb, Sn2.87Ag4.75Sb and Sn2.7Ag8.78Sb. Experimental results show that most of the added Sb are solved in -Sn matrix, and the rest react with the Ag3Sn to form Ag3(Sb,Sn) phase, which contributes to suppress the coarsening of Ag3Sn phase. SbSn phase can be observed in β-Sn matrix as the Sb addition exceeds 4.75% and remains stable during the thermal storage test. The solder microhardness increases with increasing Sb. And the growth rate of interfacial IMC layer decreases as Sb addition increases. EPMA analysis indicates there are some Sb diffusing into the interfacial IMC layer. Shear strength of solder joints are raised by adding Sb. The shear strength by as-soldered condition are 27.8MPa (0%Sb), 29MPa (1.75%Sb), 30.4MPa (4.75%Sb) and 43.4MPa (8.78%Sb) respectively

Effect of Ni-Coated Carbon Nanotubes on Interfacial Reaction and Shear Strength of Sn-Ag-Cu Solder Joints

2012 ◽  
Vol 41 (9) ◽  
pp. 2478-2486 ◽  
Author(s):  
Y. D. Han ◽  
H. Y. Jing ◽  
S. M. L. Nai ◽  
L. Y. Xu ◽  
C. M. Tan ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Shear Strength ◽  
Interfacial Reaction ◽  
Solder Joints ◽  
Coated Carbon

Interfacial reactions of Sn–Cu and Sn–Pb–Ag solder with Au/Ni during extended time reflow in ball grid array packages

2004 ◽  
Vol 19 (10) ◽  
pp. 2897-2904 ◽  
Author(s):  
M.N. Islam ◽  
Y.C. Chan ◽  
A. Sharif
Keyword(s):  
Growth Rate ◽  
Shear Strength ◽  
Solder Joint ◽  
Intermetallic Compounds ◽  
Solder Joints ◽  
Interfacial Reactions ◽  
Extended Time ◽  
Reflow Time ◽  
Ternary Intermetallic Compounds ◽  
Ball Grid Array Packages

Lead-free solders with high Sn content cause excessive interfacial reactions at the interface with under-bump metallization during reflow. The interface formed after reflow affects the reliability of the solder joint. For this paper, we investigated the interfacial reactions of Sn0.7Cu and Sn36Pb2Ag solder on electrolytic Ni layer for different reflow times. The traditionally used Sn36Pb2Ag solder was used as a reference. It was found that during as-reflowed, the formation of Cu-rich Sn–Cu–Ni ternary intermetallic compounds (TIMCs) at the interface of Sn0.7Cu solder with electrolytic Ni is much quicker, resulting in the entrapment of some Pb (which is present as impurity in the Sn–Cu solder) rich phase in the TIMCs. During extended time of reflow, high (>30 at.%), medium (30-15 at.%) and low (<15 at.%) Cu TIMCs formed at the interface. The amount of Cu determined the growth rate of TIMCs. Cu-rich TIMCs had higher growth rate and consumed more Ni layer. By contrast, the growth rate of the Ni–Sn binary intermetallic compounds (BIMCs) in the Sn36Pb2Ag solder joint was slower, and the Ni–Sn BIMC was more stable and adherent. The dissolution rate of electrolytic Ni layer for Sn0.7Cu solder joint was higher than the Sn36Pb2Ag solder joints. Less than 3 μm of the electrolytic Ni layer was consumed during molten reaction by the higher Sn containing Sn0.7Cu solder in 180 min at 250 °C. The shear strength of Sn–Pb–Ag solder joints decreased within 30 min of reflow time from 1.938 to 1.579 kgf due to rapid formation of ternary Ni–Sn–Au compounds on the Ni–Sn BIMCs. The shear strength of Sn0.7Cu solder joint is relatively stable from 1.982 to 1.861 kgf during extended time reflow. Cu prevents the resettlement of Au at the interface. The shear strength does not depend on the thickness of intermetallic compounds (IMCs) and reflow time. Ni/Sn–Cu solder system has higher strength and can be used during prolonged reflow.

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