Solder Fatigue Impacts of Conformal Coating for Tin Whisker Mitigation on Chip-Scale Thin Small Outline Packages

2009 ◽  
Author(s):  
Karl J. L. Geisler
Keyword(s):  
Fatigue Life ◽  
Temperature Cycling ◽  
Tin Whisker ◽  
Conformal Coating ◽  
Failure Data ◽  
Distribution Shape ◽  
Solder Fatigue ◽  
On Chip ◽  
Tin Whisker Mitigation ◽  
The Impact

This study explores the impact of polyurethane conformal coating on the solder fatigue life of 0.5 mm pitch, thin small outline package (TSOP) components. Test samples were subjected to temperature cycling from −40°C to + 100°C. Uncoated samples were tested in addition to sets with 10, 13, and 20 μm thick coatings. Solder joint failure data fit to 3-parameter Weibull distributions demonstrate characteristic fatigue life reductions of 30% with increasing coating thickness but relatively subtle changes to the failure distribution shape.

Effect of Corner Staking on the Fatigue Life of BGA Under Thermal Cycling

2017 ◽  
Author(s):  
Deng Yun Chen ◽  
Michael Osterman
Keyword(s):  
Fatigue Life ◽  
Thermal Cycling ◽  
Material Properties ◽  
Solder Joints ◽  
Material Selection ◽  
Temperature Cycling ◽  
Sac305 Solder ◽  
Element Analysis ◽  
Bga Packages ◽  
The Impact

Solder interconnects in electronic assemblies are susceptible to failures due to environmental high strain rate impact and cyclic stresses. To mitigate the failures, adhesive bonds can be added after the solder assembly process to provide additional mechanical support. For ball grid array (BGA) packages, the adhesive is normally applied to the corners of the package and referred to as corner staking. In addition to corner staking, underfill is also a strategy used to mitigate the stresses on the solder joints. While components with underfill has been widely studied, the study of the impact of corner staking on the reliability of packages remains limited. This paper presents a study of corner-staked BGA packages with tin-3.0 silver-0.5 copper (SAC305) solder subjected to temperature cycling. Experimental temperature cycling is conducted to examine impact of the selected corner staking material on the fatigue life of BGAs. Further, finite element analysis is conducted to understand the influence of material properties of staking material on the fatigue life of BGAs. The result of the study indicates that the presence of corner staking, with selected material properties, reduces the damage on the solder joints under thermal cycling, and thus increases its fatigue life by about 80%. This paper may serve as a guidance for staking material selection to improve the fatigue life of solder joints of BGAs under thermal cycling.

Evaluating the Impact of Dwell Time on Solder Interconnect Durability under Bending Loads

2012 ◽  
Vol 2012 (1) ◽  
pp. 000510-000513
Author(s):  
Sandeep Menon ◽  
Michael Osterman ◽  
Michael Pecht
Keyword(s):  
Fatigue Life ◽  
Dwell Time ◽  
Hold Time ◽  
Temperature Cycling ◽  
Temperature Cycle ◽  
Mechanical Loads ◽  
Solder Interconnects ◽  
Solder Interconnect ◽  
Electronic Assemblies ◽  
The Impact

With increased portability and miniaturization of modern day electronics, the mechanical robustness of these systems has become more of a concern. Existing standards for conducting mechanical durability tests of electronic assemblies include bend, shock/drop, vibration and torsion. Though these standards provide insights into both cyclic fatigue and overstress damage incurred in the solder interconnects (widely regarded as the primary mode of failure in electronic assemblies), they fail to address the impact of time dependent (creep) behavior due to sustained mechanical loads on the solder interconnect durability. It has been seen that the solder durability under thermal cycling loads is inversely proportional to the dwell time or hold time at either temperature extreme of the imposed temperature cycle. Fatigue life models, which include dwell time, have been developed for solder interconnects subject to temperature cycling. However the fatigue life models that have been developed in literature for solder interconnects under mechanical loads fail to address the impact the duration of loading. In this study, solder interconnect test vehicles were subject to cyclic mechanical bending with varying dwell times in order to understand the impact of duration of mechanical loads on the solder interconnect durability. The solder interconnects examined in this study were formed with 2512 resistor packages using varying solder compositions (SnPb and SAC305). In order to evaluate the impact of dwell time, the boards were tested with a 60 second and a 300 second dwell time on both extremes of the loading profile. It was observed that an increase in dwell time of the loading profile resulted in a decrease in the characteristic life of the solder interconnects.

Design of Experiments in Ball Grid Array Thermal Fatigue Life Tests

2002 ◽  
Author(s):  
T. E. Wong ◽  
C. Y. Lau ◽  
L. A. Kachatorian ◽  
H. S. Fenger ◽  
I. C. Chen
Keyword(s):  
Fatigue Life ◽  
Thermal Fatigue ◽  
Solder Joints ◽  
Ball Grid Array ◽  
Temperature Cycling ◽  
Design Parameters ◽  
Physical Analysis ◽  
Printed Wiring Board ◽  
Thermal Fatigue Life ◽  
The Impact

The objective of the present study is to evaluate the impact of electronic packaging design/manufacturing process parameters on the thermal fatigue life of ball grid array (BGA) solder joints. The four selected parameters are BGA under-fill materials, conformal coating, solder pad sizes on printed wiring board, and BGA rework, with each having either two or three levels of variation. A test vehicle (TV), on which various sizes of BGA daisy-chained packages are soldered, is first designed and fabricated, and then subjected to temperature cycling (−55°C to +125°C) with continuous monitoring of solder joint integrity. The total of 15 experimental cases is used in the present study. Based on monitored results, a destructive physical analysis is conducted to further isolate the failure locations and determine the failure mechanisms of the solder joints. Test results indicate that the influence of these design parameters on fatigue life is dependent on the particular package, in some instances improving the fatigue life tenfold.

Development of New Power MOSFETs Package With Double-Sided Cooling

2007 ◽  
Author(s):  
Kisho Ashida ◽  
Akira Muto ◽  
Ichio Shimizu ◽  
Kenya Kawano ◽  
Naotaka Tanaka ◽  
...  
Keyword(s):  
Fatigue Life ◽  
Thermal Resistance ◽  
Fatigue Fracture ◽  
Design Method ◽  
Temperature Cycling ◽  
Optimum Structure ◽  
Packaging Technology ◽  
Experimental Design Method ◽  
Solder Fatigue ◽  
Number Of Cycles

We developed a new packaging technology, one that uses double-sided cooling to dramatically reduce the on-resistance and thermal resistance. The main features of this technology are as follows. Both sides of the chip are soldered to copper leadframes. After that, copper leadframes soldered to the top and bottom of the chip are exposed when transfer molding encapsulates the package. There were two development problems with packaging technology. The first is how to prevent chip crack in the reflow process. The second is how to improve the fatigue life of solder during the temperature cycling. To solve these problems, we designed our package structure using an experimental design method. In particular, for the second problem, we quantitatively calculated the amount of solder fatigue fracture and the number of cycles using the solder crack propagation analysis method, because the performance of the package depends on the amount of solder fatigue fracture. As a result, we could create a condition that prevented chip crack and improved the fatigue life of solder by the twice compared to the first prototype and determined the optimum structure. We assembled a new package based on this optimum structure, and confirmed this improvement of the reliability. In addition, we measured the on-resistance and thermal resistance of this package and that of the existing package available. We found that the new package’s on-resistance and thermal resistance decreased to about 70 and 80% that of the existing package respectively.

Long-term thermal aging of parylene conformal coating under high humidity and its effects on tin whisker mitigation

2021 ◽  
pp. 109667
Author(s):  
Preeth Sivakumar ◽  
Surbhi Mahajan Du ◽  
Matt Selter ◽  
Imani Ballard ◽  
John Daye ◽  
...  
Keyword(s):  
Thermal Aging ◽  
High Humidity ◽  
Tin Whisker ◽  
Conformal Coating ◽  
Tin Whisker Mitigation

COTS BGA Thermal Fatigue Test for Avionics Applications

2003 ◽  
Author(s):  
H. S. Fenger ◽  
T. E. Wong
Keyword(s):  
Fatigue Life ◽  
Solder Joint ◽  
Thermal Fatigue ◽  
Prediction Models ◽  
Thermal Environment ◽  
Temperature Cycling ◽  
Physical Analysis ◽  
Test Results ◽  
Conformal Coating ◽  
Design And Manufacturing

The objectives of the present studies are to design and test representative commercial off-the-shelf plastic encapsulated microcircuits, including various types of ball grid array (BGA) components, chip scale package, and flip chip over military thermal environment. The approach is to demonstrate the solder joint reliability performance of these components through the design of an electrical daisy-chain pattern printed wiring board (PWB) assembly test vehicle (TV), in which the design and manufacturing variables are included. The variables, including the types of PWBs, conformal coating, and BGA underfilled materials, with each having either two or three levels of variation are used to address test criteria and to construct 12 different types of TV configurations. All TV configurations are then subjected to temperature cycling tests (−55°C to +125°C) while continuously monitoring solder joint integrity. Based on the measured results, a destructive physical analysis is then conducted to further isolate the failure locations and determine the failure mechanisms of the solder joints. Based on the lesson-learned from the above TV, a second TV (defined as TV2) has been designed, constructed and tested. The four selected parameters in TV2 are BGA under-fill materials, conformal coating, solder pad sizes on PWB, and BGA rework, with each also having either two or three levels of variation. Test results from these two groups of TVs indicate that the influence of these design and manufacturing parameters on fatigue life is dependent on the particular package, in some instances improving the fatigue life tenfold. All these test results are recommended to be used for calibrating BGA solder joint thermal fatigue life prediction models, which will be presented in other publications.

Failure Analysis Enhancement by Incorporating a Compact Scan Diagnosis System

2014 ◽  
Author(s):  
Rommel Estores ◽  
Pascal Vercruysse ◽  
Karl Villareal ◽  
Eric Barbian ◽  
Ralph Sanchez ◽  
...  
Keyword(s):  
Data Analysis ◽  
Failure Analysis ◽  
Real Analysis ◽  
Failure Data ◽  
Analysis Methodology ◽  
Efficiency And Effectiveness ◽  
Scan Chain ◽  
On Chip ◽  
Analysis Environment ◽  
Selection Of

Abstract The failure analysis community working on highly integrated mixed signal circuitry is entering an era where simultaneously System-On-Chip technologies, denser metallization schemes, on-chip dissipation techniques and intelligent packages are being introduced. These innovations bring a great deal of defect accessibility challenges to the failure analyst. To contend in this era while aiming for higher efficiency and effectiveness, the failure analysis environment must undergo a disruptive evolution. The success or failure of an analysis will be determined by the careful selection of tools, data and techniques in the applied analysis flow. A comprehensive approach is required where hardware, software, data analysis, traditional FA techniques and expertise are complementary combined [1]. This document demonstrates this through the incorporation of advanced scan diagnosis methods in the overall analysis flow for digital functionality failures and supporting the enhanced failure analysis methodology. For the testing and diagnosis of the presented cases, compact but powerful scan test FA Lab hardware with its diagnosis software was used [2]. It can therefore easily be combined with the traditional FA techniques to provide stimulus for dynamic fault localizations [3]. The system combines scan chain information, failure data and layout information into one viewing environment which provides real analysis power for the failure analyst. Comprehensive data analysis is performed to identify failing cells/nets, provide a better overview of the failure and the interactions to isolate the fault further to a smaller area, or to analyze subtle behavior patterns to find and rationalize possible faults that are otherwise not detected. Three sample cases will be discussed in this document to demonstrate specific strengths and advantages of this enhanced FA methodology.

scholarly journals Fatigue Testing of Wearable Sensing Technologies: Issues and Opportunities

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4070
Author(s):  
Andrea Karen Persons ◽  
John E. Ball ◽  
Charles Freeman ◽  
David M. Macias ◽  
Chartrisa LaShan Simpson ◽  
...  
Keyword(s):  
Fatigue Life ◽  
Prediction Models ◽  
Fatigue Testing ◽  
Low Cycle Fatigue ◽  
Wearable Sensors ◽  
Fatigue Tests ◽  
Proof Of Concept ◽  
Cycle Fatigue ◽  
Wearable Sensing ◽  
Failure Data

Standards for the fatigue testing of wearable sensing technologies are lacking. The majority of published fatigue tests for wearable sensors are performed on proof-of-concept stretch sensors fabricated from a variety of materials. Due to their flexibility and stretchability, polymers are often used in the fabrication of wearable sensors. Other materials, including textiles, carbon nanotubes, graphene, and conductive metals or inks, may be used in conjunction with polymers to fabricate wearable sensors. Depending on the combination of the materials used, the fatigue behaviors of wearable sensors can vary. Additionally, fatigue testing methodologies for the sensors also vary, with most tests focusing only on the low-cycle fatigue (LCF) regime, and few sensors are cycled until failure or runout are achieved. Fatigue life predictions of wearable sensors are also lacking. These issues make direct comparisons of wearable sensors difficult. To facilitate direct comparisons of wearable sensors and to move proof-of-concept sensors from “bench to bedside,” fatigue testing standards should be established. Further, both high-cycle fatigue (HCF) and failure data are needed to determine the appropriateness in the use, modification, development, and validation of fatigue life prediction models and to further the understanding of how cracks initiate and propagate in wearable sensing technologies.

Improving Fatigue Life of Riveted Joints by Rivet Hole Sizing

2014 ◽  
Vol 598 ◽  
pp. 141-146
Author(s):  
Adam Lipski ◽  
Zbigniew Lis
Keyword(s):  
Fatigue Life ◽  
Fold Increase ◽  
Fatigue Tests ◽  
Aviation Industry ◽  
Lap Joint ◽  
Riveted Joints ◽  
Riveting Process ◽  
The Difference ◽  
Structural Connection ◽  
The Impact

The aim of this paper is to assess the impact of the rivet hole sizing process on the fatigue life based on the example of the structural connections characteristic for riveted joints used in aviation industry. Test specimens reflected the structural connection consisting in a riveted lap joint of an airplane plating stiffened with a T-bar. Connected plates and the T-bar are made of D16CzATW aluminum alloy. 3 mm diameter oval head solid rivets for aviation-related purposes were made of PA24 aluminum. During fatigue tests, individual specimens with non-sized holes and with sized holes were subjected to uniaxial, one-sided, fixed-amplitude loading (R = 0). It can be concluded from the fatigue life comparison that introduction of an additional operation in the riveting process, i.e. the hole sizing, results in significant, about two-fold increase of the fatigue life of the riveted structural connection, even at slight sizing degree. The difference of the specimen damage nature was observed between specimens with sized and non-sized holes.

scholarly journals Thermographic Study of Chip Temperature in High-Speed Dry Milling Magnesium Alloys

2016 ◽  
Vol 7 (2) ◽  
pp. 86-92 ◽  
Author(s):  
Józef Kuczmaszewski ◽  
Ireneusz Zagórski ◽  
Piotr Zgórniak
Keyword(s):  
Temperature Measurement ◽  
Magnesium Alloys ◽  
High Speed ◽  
Machining Process ◽  
Dry Milling ◽  
Technological Parameters ◽  
Chip Temperature ◽  
Thermographic Study ◽  
On Chip ◽  
The Impact

Abstract This paper presents an overview of the state of knowledge on temperature measurement in the cutting area during magnesium alloy milling. Additionally, results of own research on chip temperature measurement during dry milling of magnesium alloys are included. Tested magnesium alloys are frequently used for manufacturing elements applied in the aerospace industry. The impact of technological parameters on the maximum chip temperature during milling is also analysed. This study is relevant due to the risk of chip ignition during the machining process.

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