Simulative Analysis on Factors Influencing Solder Joint Bridging of Fine Pitch Devices

2004 ◽  
Vol 126 (1) ◽  
pp. 22-25 ◽  
Author(s):  
Li Ming Yu ◽  
Bang Han Sur ◽  
Kim Young Pyo ◽  
Wang Chun Qing ◽  
Zhang Lei
Keyword(s):  
Surface Tension ◽  
Solder Joint ◽  
3D Model ◽  
Solder Joints ◽  
Wetting Angle ◽  
Forming Process ◽  
Surface Evolver ◽  
Effective Factors ◽  
Factors Influencing ◽  
Fine Pitch

Solder bridging is one of the most serious defects of solder joint in fine pitch device assemblies. It is known that the generation of solder bridging is closely related to the forming process of solder joints. To simulate the process, a 3D model is formed. Then it is numerically simulated using Surface Evolver program. Based on the results, the solder bridging mechanism and the effective factors including wetting angle and surface tension are investigated.

Predicting the Liquid Formation for the Solder Joints in Flip Chip Technology

2005 ◽  
Vol 128 (4) ◽  
pp. 331-338 ◽  
Author(s):  
Wen-Hwa Chen ◽  
Shu-Ru Lin ◽  
Kuo-Ning Chiang
Keyword(s):  
Surface Tension ◽  
Solder Joint ◽  
Flip Chip ◽  
Solder Joints ◽  
Geometric Method ◽  
External Loading ◽  
Surface Evolver ◽  
Eutectic Solder ◽  
Chip Technology ◽  
Interfacial Surface

An accurate and efficient analytical geometric method is presented for predicting the geometric parameters of the controlled collapse chip connection type solder joint using direct chip attach technology after a reflow process. By this method, the meridian of the solder joint is first discretized as a series of sufficiently fine fragmental arcs. After calculating the internal pressure inside the molten eutectic solder from the forces balance, the meridional and circumferential radii of curvature of each arc are then obtained from the Laplace-Young equation. As a result, the coordinates of each node of the arc and the solder joint geometry can be determined in turn. The factors that affect the final shape of the molten eutectic solder joints, including the solder volumes, external loading, pad size, surface tension of molten eutectic solder, and interfacial surface tension between the molten eutectic solder and the solid high-lead bump are considered herein. The results computed by the analytical geometric method are also compared with those obtained using the Surface Evolver program, the extended Heinrich’s model, and the experimental results. The results of the various approaches are mutually consistent.

Prediction of Liquid Formation for Solder and Non-Solder Mask Defined Array Packages

1999 ◽  
Vol 124 (1) ◽  
pp. 37-44 ◽  
Author(s):  
Wen-Hwa Chen ◽  
Kuo-Ning Chiang ◽  
Shu-Ru Lin
Keyword(s):  
Solder Joint ◽  
Solder Joints ◽  
Reflow Process ◽  
Surface Evolver ◽  
Restoring Force ◽  
Solder Mask ◽  
The Difference ◽  
Design Factors ◽  
Joint Volume ◽  
Liquid Formation

This study presents an efficient method to accurately predict solder joint geometry after a reflow process. The proposed method can be utilized for Solder Mask Defined (SMD), Non-Solder Mask Defined (NSMD), or C4 type solder joints. The reflow process involves several design factors capable of influencing the final shape of the molten solder joint, such as solder joint volume, restoring force, surface tension, contact angle, pad thickness, and pad size. These factors are all considered in the calculations. The computed results are compared with those using the Surface Evolver program and also with available numerical/experimental results. Their excellent agreement shows that the method developed herein can be practically applied to predict the reflow shape of SMD/NSMD solder joints. The difference between SMD and NSMD is also examined in detail. Results in this study provide designers with a fundamental guideline for accurately predicting the liquid formation of solder joints during the reflow process.

Electronic Packaging Reflow Shape Prediction for the Solder Mask Defined Ball Grid Array

1998 ◽  
Vol 120 (2) ◽  
pp. 175-178 ◽  
Author(s):  
K.-N. Chiang ◽  
W.-L. Chen
Keyword(s):  
Solder Joint ◽  
Electronic Packaging ◽  
Engineering Application ◽  
Contact Angles ◽  
Joint Models ◽  
Surface Evolver ◽  
Minimization Principle ◽  
Shape Prediction ◽  
Fine Pitch ◽  
Practical Engineering

The increasing need to create high density and fine pitch electronic interconnections presents a number of challenges. The fatigue-induced solder joint failure of surface mounted electronic devices has become one of the most critical reliability issues in electronic packaging industry. Prediction of the shape of solder joint has drawn special attention in the development of electronic packaging for its practical engineering application. Many solder joint models have been developed based on energy minimization principle (Patra et al., 1995) or analytical method (Heinrich et al., 1993; Liedtke 1993). These methods are extensively utilized to the shape design of solder joint. However, it is important to find a suitable method in real application. In this study, an efficient numerical method used to predict the shapes of solder joint is investigated, and the results are compared with Surface Evolver program (Brakke, 1994). The changes of geometric shape with respect to different parameters of solder joint are also discussed in this paper. The influences of the geometric parameters, such as volumes of solder joint, package weight, contact angles, pads sizes, solder surface tension, and gravity forces to the shape of solder joint, are investigated. Results presented in this study can be used to determined the optimally balanced stand-off height of single ball module (SBM) or multiple ball module (MBM) solder joint models.

Solder Joint Formation in Surface Mount Technology—Part II: Design

1990 ◽  
Vol 112 (3) ◽  
pp. 219-222 ◽  
Author(s):  
S. M. Heinrich ◽  
N. J. Nigro ◽  
A. F. Elkouh ◽  
P. S. Lee
Keyword(s):  
Surface Tension ◽  
Solder Joint ◽  
Solder Joints ◽  
Cross Sectional Area ◽  
Surface Mount Technology ◽  
Sectional Area ◽  
Cross Sectional ◽  
Joint Formation ◽  
Surface Mount ◽  
Surface Tension Model

In this paper dimensionless design curves relating fillet height and length to joint cross-sectional area are presented for surface-mount solder joints. Based on an analytical surface tension model, the advantage of these dimensionless curves is that they may be used for arbitrary values of solder density and surface tension. The range of applicability of previously developed approximate formulae for predicting joint dimensions is also investigated. A simple example problem is included to illustrate the use of both the design curves and the approximate formulae.

A First Individual Solder Joint Encapsulant Adhesive

2010 ◽  
Vol 2010 (1) ◽  
pp. 000766-000770 ◽  
Author(s):  
Mary Liu ◽  
Wusheng Yin
Keyword(s):  
Thermal Stress ◽  
Solder Joint ◽  
Solder Joints ◽  
Empty Space ◽  
Pull Strength ◽  
Fine Pitch ◽  
3D Package

In order to meet the demand of fine pitch and 3D package, and eliminate complex underfilling process, a first solder joint encapsulant has been invented. Solder joint encapsulant adhesive is to encapsulate each individual solder joint using polymer to enhance solder joint, and leave empty space in-between solder joints to avoid thermal stress applied onto solder joints. Now two kinds of solder joint encapsulants are SMT256 and SMT266, which have been used in the customer field. Using solder joint encapsulants – SMT256 and SMT266, the pull strength of solder joint has been increased by about five times, resulting in significant increase in the reliability. In this paper more details have been investigated.

Seamless Tool Integration for Solder Joint Qualifications

2008 ◽  
Author(s):  
Zhengfang Qian ◽  
Xin Wu
Keyword(s):  
Solder Joint ◽  
Printed Circuit Board ◽  
Solder Joints ◽  
Constitutive Models ◽  
Failure Criteria ◽  
Circuit Board ◽  
Reliability Prediction ◽  
Tool Integration ◽  
Electronic Components ◽  
Surface Evolver

This paper presents an approach and its demonstration for seamless tool integration for the virtual qualification and reliability prediction of solder joints of surface mounted electronic components on a populated circuit board. Starting from software called Surface Evolver, it can be used to realistically reproduce complicated geometry profiles of solder joints with various lead frames and pad specifications. User routines have been developed under ANSYS platform for automatic geometry transfer from the Surface Evolver and mesh regeneration of the solder joints inside ANSYS, as demonstrated in this paper. Moreover, a number of electronic packages with their solder joints on a typical printed circuit board (PCB) were also regenerated with parametric capability. Finite element analyses (FEAs) with proper set-up of materials, boundary conditions, and constitutive models were performed automatically by hitting one-button to go. Reliability prediction of solder joints and the failure rate of electronic components can be predicted based on failure criteria and test data implemented. An in-house tool was developed for the whole procedure of solder joint qualification and reliability assessment from deterministic to statistical aspects, including the evaluation of defect impacts.

Solder Joint Shape Prediction Using a Modified Perzyna Viscoplastic Model

2004 ◽  
Vol 127 (3) ◽  
pp. 290-298 ◽  
Author(s):  
Mudasir Ahmad ◽  
Ken Hubbard ◽  
Mason Hu
Keyword(s):  
Surface Tension ◽  
Numerical Model ◽  
Solder Joint ◽  
Solder Joints ◽  
Element Analysis ◽  
Closed Form Solutions ◽  
Joint Construction ◽  
Shape Prediction ◽  
Applied Forces ◽  
Joint Shape

Ball grid array solder joint reliability is known to be dependent on the shape of solder joints after reflow. To ensure good solder joint formation and prevent solder bridging, it is critical to understand the amount of paste volume needed during assembly and reflow. The final shape of the solder joint is a function of surface tension, wetting area, gravity, and applied forces. In this paper, a new methodology to simulate solder joint shape is presented. Large deformation viscoplastic finite element analysis is used to simulate incompressible fluid flow. A numerical model for surface tension is outlined and validated with closed-form solutions. The results of the numerical model are compared to other known solder joint shape prediction methods. The effects of package weight, coplanarity, warpage, paste volume, pad misregistration, and joint construction on solder joint shape are then analyzed. Recommendations are provided on ways to maximize standoff height and avoid bridging. Finally, the formation of leadless solder joints is studied and compared to experimental data.

Reballing/Rebumping Ultra-Fine Pitch Packages Less Than 0.5 mm Pitch for FA

2014 ◽  
Author(s):  
Bob Wettermann
Keyword(s):  
Solder Joint ◽  
Failure Analysis ◽  
Joint Strength ◽  
Semiconductor Devices ◽  
X Ray ◽  
Fine Pitch ◽  
Manual Methods

Abstract As the pitch and package sizes of semiconductor devices have shrunk and their complexity has increased, the manual methods by which the packages can be re-bumped or reballed for failure analysis have not kept up with this miniaturization. There are some changes in the types of reballing preforms used in these manual methods along with solder excavation techniques required for packages with pitches as fine as 0.3mm. This paper will describe the shortcomings of the previous methods, explain the newer methods and materials and demonstrate their robustness through yield, mechanical solder joint strength and x-ray analysis.

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.

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.

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