Environmental and endurance testing. Test methods for surface-mount boards of area array type packages FBGA, BGA, FLGA, LGA, SON and QFN

2015 ◽  
Keyword(s):  
Test Methods ◽  
Array Type ◽  
Surface Mount ◽  
Area Array ◽  
Endurance Testing

Demonstration of the Benefits of SAE 30 Stationary Gas Engine Oil in Full Scale Engine Tests

2021 ◽  
Author(s):  
Thijs Schasfoort ◽  
Zoe Fard ◽  
Torsten Gehrmann ◽  
Steffen Hollatz
Keyword(s):  
Positive Impact ◽  
Fuel Efficiency ◽  
Test Methods ◽  
Operating Conditions ◽  
Engine Oil ◽  
Gas Engine ◽  
Fuel Consumption Rate ◽  
Efficiency Performance ◽  
Endurance Testing ◽  
Efficiency Test

Abstract This paper evaluates the benefits of an SAE 30 monograde stationary gas engine oil (SGEO) in comparison with SAE 40 monograde SGEOs with the focus on two main areas. First, to demonstrate and quantify the positive impact of lower viscosity on the fuel consumption rate, and second to demonstrate the faster lubrication of hard to reach points in the engine during startup. The current industry recognized fuel efficiency test methods for passenger car and on-road diesel engine sectors are not suitable for evaluating the fuel efficiency performance of a gas engine oil because of the significant differences in fuel type, engine operating conditions, and oil formulations. This paper, therefore, describes comparative studies of three different gas engine oils in a modern MAN E3262 E302 gas engine that was carefully adapted and fully instrumented. The performance of each oil with respect to fuel efficiency was assessed in an extensive program comprising endurance testing, stationary tests on various load/speed points and dynamic tests running the engine fired as well as non-fired (motored). Another part of the test program explores the lubrication of hard to reach points in the engine, e.g. valve guide. The paper describes how the SAE 30 monograde oil results in faster lubrication of these parts during startup in comparison with the SAE 40 oils.

A Comparison of Thermal Stress/Strain Behavior of Elliptical/Round Solder Pads

1999 ◽  
Vol 123 (2) ◽  
pp. 127-131 ◽  
Author(s):  
Kuo-Ning Chiang ◽  
Chang-Ming Liu
Keyword(s):  
Thermal Stress ◽  
Solder Joint ◽  
Solder Joints ◽  
Numerical Models ◽  
Ball Grid Array ◽  
Stress Strain ◽  
Restoring Force ◽  
Array Type ◽  
Finite Element Software ◽  
Area Array

As electronic packaging technology moving to the CSP, wafer level packaging, fine pitch BGA (ball grid array) and high density interconnections, the wireability of the PCB/substrate and soldering technology are as important as reliability issues. In this work, a comparison of elliptical/round pads of area array type packages has been studied for soldering, reliability, and wireability requirements. The objective of this research is to develop numerical models for predicting reflow shapes of solder joint under elliptical/round pad boundary conditions and to study the reliability issue of the solder joint. In addition, a three-dimensional solder liquid formation model is developed for predicting the geometry, the restoring force, the wireability, and the reliability of solder joints in an area array type interconnections (e.g., ball grid array, flip chip) under elliptical and round pad configurations. In general, the reliability of the solder joints is highly dependent on the thermal-mechanical behaviors of the solder and the geometry configuration of the solder ball. These reliability factors include standoff height/contact angle of the solder joint, and the geometry layout/material properties of the package. An optimized solder pad design cannot only lead to a good reliability life of the solder joint but also can achieve a better wireability of the substrate. Furthermore, the solder reflow simulation used in this study is based on an energy minimization engine called Surface Evolver and the finite element software ABAQUS is used for thermal stress/strain nonlinear analysis.

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