The Future of Solder Joint Encapsulant

2015 ◽  
Vol 2015 (1) ◽  
pp. 000644-000648
Author(s):  
Mary Liu ◽  
Wusheng Yin
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Solder Joint ◽  
Thermal Cycling ◽  
Lower Cost ◽  
Solder Joints ◽  
Cost Of Ownership ◽  
The Future ◽  
High Temperature Solder

Solder joint encapsulant adhesives have been successfully used to enhance the strength of solder joints and improve thermal cycling as well as drop performance in finished products. The use of solder joint encapsulant adhesives can eliminate the need for underfill materials and the underfill process altogether, thus simplifying rework, which results in a lower cost of ownership. Solder joint encapsulant adhesives include: low temperature and high temperature solder joint encapsulant adhesives, and their derivatives. Each solder joint encapsulant adhesive has: unfilled and filled solder joint encapsulant adhesives, and solder joint encapsulant paste. Each solder joint encapsulant product has been designed for different applications. In this paper, we are going to discuss the details and future of solder joint encapsulant adhesives.

scholarly journals Study on the Reliability of Sn–Bi Composite Solder Pastes with Thermosetting Epoxy under Thermal Cycling and Humidity Treatment

Crystals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 733
Author(s):  
Lu Liu ◽  
Songbai Xue ◽  
Ruiyang Ni ◽  
Peng Zhang ◽  
Jie Wu
Keyword(s):  
Solder Joint ◽  
Thermal Cycling ◽  
Composite Solder ◽  
Solder Joints ◽  
Solder Paste ◽  
Epoxy System ◽  
Mechanical Reinforcement ◽  
Microstructure Observation ◽  
Temperature And Humidity ◽  
Thermosetting Epoxy

In this study, a Sn–Bi composite solder paste with thermosetting epoxy (TSEP Sn–Bi) was prepared by mixing Sn–Bi solder powder, flux, and epoxy system. The melting characteristics of the Sn–Bi solder alloy and the curing reaction of the epoxy system were measured by differential scanning calorimeter (DSC). A reflow profile was optimized based on the Sn–Bi reflow profile, and the Organic Solderability Preservative (OSP) Cu pad mounted 0603 chip resistor was chosen to reflow soldering and to prepare samples of the corresponding joint. The high temperature and humidity reliability of the solder joints at 85 °C/85% RH (Relative Humidity) for 1000 h and the thermal cycle reliability of the solder joints from −40 °C to 125 °C for 1000 cycles were investigated. Compared to the Sn–Bi solder joint, the TSEP Sn–Bi solder joints had increased reliability. The microstructure observation shows that the epoxy resin curing process did not affect the transformation of the microstructure. The shear force of the TSEP Sn–Bi solder joints after 1000 cycles of thermal cycling test was 1.23–1.35 times higher than the Sn–Bi solder joint and after 1000 h of temperature and humidity tests was 1.14–1.27 times higher than the Sn–Bi solder joint. The fracture analysis indicated that the cured cover layer could still have a mechanical reinforcement to the TSEP Sn–Bi solder joints after these reliability tests.

scholarly journals Prediction of mechanical properties and fatigue life of nano silver paste in chip interconnection

2020 ◽  
Author(s):  
Hui YANG ◽  
Jihui Wu
Keyword(s):  
Fatigue Life ◽  
Solder Joint ◽  
Thermal Cycling ◽  
Solder Joints ◽  
Stress And Strain ◽  
Nano Silver ◽  
Finite Element Software ◽  
Flip Chips ◽  
Empirical Correction ◽  
Prediction Of Mechanical Properties

Abstract The simulation of nano-silver solder joints in flip-chips is performed by the finite element software ANSYS, and the stress-strain distribution results of the solder joints are displayed. In this simulation, the solder joints use Anand viscoplastic constitutive model, which can reasonably simulate the stress and strain of solder joints under thermal cycling load. At the same time this model has been embedded in ANSYS software, so it is more convenient to use. The final simulation results show that the areas where the maximum stresses and strains occur at the solder joints are mostly distributed in the contact areas between the solder joints and the copper pillars and at the solder joints. During the entire thermal cycling load process, the area where the maximum change in stress and strain occurs is always at the solder joint, and when the temperature changes, the temperature at the solder joint changes significantly. Based on comprehensive analysis, the relevant empirical correction calculation equation is used to calculate and predict the thermal fatigue life of nano-silver solder joints. The analysis results provide a reference for the application of nano-silver solder in the electronic packaging industry.

Predicting Thermal Fatigue Lifetimes for SMT Solder Joints

1992 ◽  
Vol 114 (4) ◽  
pp. 472-476 ◽  
Author(s):  
J. Sauber ◽  
J. Seyyedi
Keyword(s):  
Finite Element ◽  
Solder Joint ◽  
Thermal Cycling ◽  
Thermal Fatigue ◽  
Solder Joints ◽  
Finite Element Models ◽  
Creep Tests ◽  
Creep Equation ◽  
Joint Behavior ◽  
Creep Strains

A power-law type creep equation has been added to finite element models to calculate solder joint response to time, temperature, and stress level. The ability of the models to predict solder joint behavior was verified by running a series of creep tests. The models were then solved to determine the solder joint creep strains which occur during thermal cycling. These creep strains were used to predict the degradation of pull strength resulting from thermal cycling. More than 8,600 solder joints were thermally cycled and then individually pull tested to verify the accuracy of the method.

Thermal Cycling Reliability of Chip Resistor Lead Free Solder Joints

2003 ◽  
Author(s):  
N. Islam ◽  
J. C. Suhling ◽  
P. Lall ◽  
T. Shete ◽  
H. S. Gale ◽  
...  
Keyword(s):  
Solder Joint ◽  
Thermal Cycling ◽  
Fatigue Resistance ◽  
Solder Joints ◽  
Lead Free ◽  
Lead Free Solder ◽  
Snagcu Alloy ◽  
Temperature Ranges ◽  
Free Solder

In this study, we have examined the thermal cycling reliability of several lead free chip resistor solder joint configurations. Five sizes of resistors (2512, 1206, 0805, 0603, 0402), 2 temperature ranges (−40 to 125°C and −40 to 150°C), and five different solder types have been examined. The solders include the normal SnAgCu alloy recommended by earlier studies (95.5Sn-3.8Ag-0.7Cu), and several variations that include small percentages of Bismuth and Indium to enhance fatigue resistance. Results have been compared to data for standard 63Sn-37Pb joints.

Reliability Evaluation of BGA Solder Joints by Using Thermal Fatigue Models

2005 ◽  
Author(s):  
Ouk Sub Lee ◽  
No Hoon Myoung ◽  
Dong Hyeok Kim
Keyword(s):  
Solder Joint ◽  
Thermal Cycling ◽  
Thermal Fatigue ◽  
Failure Probability ◽  
Solder Joints ◽  
State Function ◽  
Mechanical Loads ◽  
First Order ◽  
Reliability Method ◽  
Fatigue Model

The use of Ball Grid Array (BGA) interconnects utilizing the BGA solder joint has grown rapidly because of its small volume and diversity of its application. Therefore, the continuous quantification and refinement of BGA solder joint in terms of its reliability are required. The creep and cyclically applied mechanical loads generally cause metal fatigue on the BGA solder joint which inevitably leads to an electrical discontinuity. In the field application, the BGA solder joints are known to experience mechanical loads during temperature changes caused by power up/down events as the result of the Coefficient of Thermal Expansion (CTE) mismatch between the substrate and the Si die. In this paper, extremely small resistance changes in the lead free joints corresponding to the through-cracks generated by the thermal fatigue were measured and the failure was defined in terms of anomalous changes in the joint resistance. Furthermore, the reliability of BGA solder joints under thermal cycling was evaluated by using a criterion that may define and distinguish a failure in the solder joint. Any changes in circuit resistance according to the accumulated damage induced by the thermal cycling in the joint were recorded and evaluated by the First Order Reliability Method (FORM) procedure in order to quantify the reliability of solder joint. The first order Taylor series expansion of the limit state function incorporating with thermal fatigue models is used in order to estimate the failure probability of solder joints under heated condition. Various thermal fatigue models are utilized in this study. Models based on various plastic-strain rates such as Coffin-Manson fatigue model, total strain fatigue model and Solomon fatigue model are utilized in this study. The effects of random variables such as the CTE, the pitch of solder joint, the diameter of solder joint, and the CTE difference solder joints on the failure probability of the solder joint are systematically investigated by using a failure probability model with the FORM.

RELIABILITY EVALUATION OF BGA SOLDER JOINTS DURING ACCELERATED LIFE TEST

2006 ◽  
Vol 20 (25n27) ◽  
pp. 4553-4558
Author(s):  
OUK SUB LEE ◽  
NO HOON MYOUNG ◽  
DONG HYEOK KIM ◽  
MAN JAE HUR ◽  
SI WOON HWANG
Keyword(s):  
Solder Joint ◽  
Thermal Cycling ◽  
Solder Joints ◽  
Coefficient Of Thermal Expansion ◽  
Accelerated Life Test ◽  
Lead Free ◽  
Lead Free Solder ◽  
Metal Fatigue ◽  
Mechanical Loads ◽  
Free Solder

The use of BGA (Ball Grid Array) interconnects utilizing the lead-free solder joint has grown rapidly because of its small volume and diversity of application. Thus, it requires the continuous quantification and refinement of lead-free solder joint reliability. The lead-free solder creep and cyclically applied mechanical loads cause metal fatigue on the lead-free solder joint which inevitably leads to an electrical discontinuity. In the field application, BGA solder joints experience mechanical loads during temperature changes caused by power up/down events as the result of the CTE (Coefficient of Thermal Expansion) mismatch between the substrate and the Si die. In this paper, extremely small resistance changes at joint area corresponding to through-cracks generated by thermal fatigue were measured. In this way, the failure was defined in terms of anomalous changes in electrical resistance of the joint. Furthermore the reliability of BGA solder joints in thermal cycling is evaluated by using the modified coffin-Manson criterion which may define and distinguish failure. Any change in circuit resistance according to the accumulated damage induced by the thermal cycling in the joint was recorded and evaluated in order to quantitate reliability of solder joint.

scholarly journals Effect of Thermal Cyclic Loading on Stress-Strain Response and Fatigue Life of 3D Chip Stacking Structure

2020 ◽  
Author(s):  
Liang Zhang ◽  
Su-juan Zhong
Keyword(s):  
High Temperature ◽  
Fatigue Life ◽  
Cyclic Loading ◽  
Low Temperature ◽  
Dwell Time ◽  
Maximum Stress ◽  
Solder Joints ◽  
Stress Strain ◽  
3D Chip Stacking ◽  
Stacking Structure

Abstract In this paper, the thermo-mechanical reliability of IMCs (Ni3Sn4, Cu3Sn, Cu6Sn5) solder joints and Sn-3.9Ag-0.6Cu solder joints were investigated systematically in 3D chip stacking structure subjected to an accelerated thermal cyclic loading based on finite element simulation and Taguchi method. Effects of different control factors, including high temperature, low temperature, dwell time of thermal cyclic loading, and different IMCs on the stress-strain response and fatigue life of solder joints were calculated respectively. The results indicate that maximum stress-strain can be found in the second solder joint on the diagonal of IMC solder joints array, for Sn-3.9Ag-0.6Cu solder joints array the corner solder joints shows the obvious maximum stress-strain, these areas are the crack propagated locations. The stress-strain and fatigue life of solder joints is more sensitive to dwell temperature, especially to high temperature, increasing the high temperature, dwell time, or decreasing the low temperature, can reduce the stress-strain and enlarge the fatigue life of solder joints. The optimal design in the 3D IC structure has the combination of the Cu6Sn5/Cu3Sn, 373K high temperature, 233K low temperature, and 10min dwell time.

Effect of Fe content on the interfacial reliability of SnAgCu/Fe-Ni solder joint

2013 ◽  
Vol 2013 (1) ◽  
pp. 000109-000114
Author(s):  
Hao Zhang ◽  
Qing-Sheng Zhu ◽  
Zhi-Quan Liu ◽  
Li Zhang ◽  
Hongyan Guo ◽  
...  
Keyword(s):  
High Temperature ◽  
Solder Joint ◽  
Solder Joints ◽  
Temperature Cycling ◽  
Growth Speed ◽  
Fe Content ◽  
Ball Shear Test ◽  
High Temperature Storage ◽  
Interfacial Reliability ◽  
Temperature Storage

Fe-Ni films with compositions of Fe-75Ni, Fe-50Ni, and Fe-30Ni were used as under bump metallization (UBM) to evaluate the interfacial reliability of SnAgCu/Fe-Ni solder joints through ball shear test, high temperature storage, as well as temperature cycling. The shear strength for Fe-75Ni, Fe-50Ni, and Fe-30Ni solder joints after reflow were 42.57, 53.94, 53.98 MPa respectively, which are all satisfied with the requirement of industrialization (>34.3 MPa ). High temperature storage was conducted at 150°C and 200°C respectively. It was found that higher Fe content in Fe-Ni layer had the ability to inhibit the mutual diffusion at interface region at 150°C, and the growth speed of intermetallic compound (IMC) decreased with the increase of Fe concentration. When stored at 200°C, the thickness of IMC would reach a limitation for all these three films after 4 days, and cracks occurred at the interface between IMC and Fe-Ni layer. Temperature cycling tests revealed that SnAgCu/Fe-50Ni solder joint had the lowest failure rate (less than 10%), which has the best interfacial reliability among three compositions.

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