Shadow Moire´ Evaluation of Motherboard Warpage Under Preload CPU Thermal Solutions

2005 ◽  
Author(s):  
Phil Geng ◽  
Robert R. Martinson ◽  
Richard L. Williams ◽  
Michael Mello ◽  
Steve Cho
Keyword(s):  
Elevated Temperature ◽  
Failure Mode ◽  
Room Temperature ◽  
Moire Interferometry ◽  
Heating Stage ◽  
Shadow Moire ◽  
Shadow Moiré ◽  
Creep Effect ◽  
Local Board ◽  
Temperature Correlations

This work investigated the motherboard coplanarity and preload correlation using the shadow moire´ interferometry. Motherboards under three different preloads in the CPU area were examined at room temperature and elevated temperature. Both the global board warpage and the local board warpage around the CPU area were measured for preload and temperature correlations. The measured board coplanarity was correlated to the board preload successfully. The results clearly identified a failure mode from the outlier, which has totally different warpage shape and corresponds to the uneven preload case. Also, the creep effect under preload during heating stage was observed and quantified.

Surface Warpage Measurement of Wood at Elevated Temperature by Shadow Moiré Method

2013 ◽  
Vol 303-306 ◽  
pp. 799-802
Author(s):  
Terry Yuan Fang Chen ◽  
Yu Sheng Chen
Keyword(s):  
Elevated Temperature ◽  
Room Temperature ◽  
Field Method ◽  
Test Results ◽  
Full Field ◽  
Contact Type ◽  
Shadow Moire ◽  
Shadow Moiré ◽  
Moire Method ◽  
Good Agreement

A full-field method to measure the surface warpage of wood plate at elevated temperature by phase-shifted shadow moiré method is presented. Test of the method on a cypress wood plate is demonstrated. A comparison of the test results at room temperature to the ones obtained by contact type sensor was made. A good agreement between them is shown. Further measurement of the plate warpage at elevated temperature reveals the warping behavior of wood plate.

The Static Mechanical Property of Concrete at Elevated Temperature

2011 ◽  
Vol 261-263 ◽  
pp. 212-216
Author(s):  
Jun Lin Tao ◽  
Li Bo Qin ◽  
Kui Li ◽  
Bin Jia
Keyword(s):  
Mechanical Property ◽  
Elevated Temperature ◽  
Room Temperature ◽  
Critical Strain ◽  
Plain Concrete ◽  
Constitutive Relationship ◽  
Heating Method ◽  
Experiment System ◽  
Wave Heating ◽  
Static Mechanical

Using micro-wave heating method, the previous disadvantages of heating slowly and non-uniform are broken through. And plain concrete high temperature loading experiment system is composed of the method and material experiment machine. Many experiments of self-made concrete are carried out from room temperature to 600°C by this system. The strength and critical strain of concrete with temperature are obtained, and through analysis of the compressive stress-strain curves under different temperature, the constitutive relationship is established. The result shows that this constitutive relationship is greatly agrees with experiment. Meanwhile, the phenomenon is analyzed and explained in the progress of experiment.

An accurate method to calibrate shadow moiré measurement sensitivity

2019 ◽  
Vol 30 (12) ◽  
pp. 125021
Author(s):  
Wei Zhang ◽  
Fulong Zhu ◽  
Shenghuai Wang ◽  
Pengyan Lu ◽  
Xin Wu
Keyword(s):  
Accurate Method ◽  
Measurement Sensitivity ◽  
Shadow Moire ◽  
Shadow Moiré

Effects of Elevated Temperatures on the Compressive Strength of HFCC

2011 ◽  
Vol 261-263 ◽  
pp. 416-420 ◽  
Author(s):  
Fu Ping Jia ◽  
Heng Lin Lv ◽  
Yi Bing Sun ◽  
Bu Yu Cao ◽  
Shi Ning Ding
Keyword(s):  
Compressive Strength ◽  
Elevated Temperature ◽  
Fly Ash ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Relative Strength ◽  
Ordinary Concrete ◽  
Residual Compressive Strength ◽  
Fly Ash Concrete ◽  
The Relationship

This paper presents the results of elevated temperatures on the compressive of high fly ash content concrete (HFCC). The specimens were prepared with three different replacements of cement by fly ash 30%, 40% and 50% by mass and the residual compressive strength was tested after exposure to elevated temperature 250, 450, 550 and 650°C and room temperature respectively. The results showed that the compressive strength apparently decreased with the elevated temperature increased. The presence of fly ash was effective for improvement of the relative strength, which was the ratio of residual compressive strength after exposure to elevated temperature and ordinary concrete. The relative compressive strength of fly ash concrete was higher than those of ordinary concrete. Based on the experiments results, the alternating simulation formula to determine the relationship among relative strength, elevated temperature and fly ash replacement is developed by using regression of results, which provides the theoretical basis for the evaluation and repair of HFCC after elevated temperature.

Phase Relationship Studies of Silicon Nitride System—A Key to Materials Design

1992 ◽  
Vol 287 ◽  
Author(s):  
T.S. Yen ◽  
W.Y. Sun
Keyword(s):  
Elevated Temperature ◽  
Silicon Nitride ◽  
Grain Boundary ◽  
Phase Behavior ◽  
Phase Diagrams ◽  
Room Temperature ◽  
Phase Relationship ◽  
Materials Design ◽  
Basic Approach ◽  
System A

ABSTRACTAdditions and revisions to several of the most important phase diagrams and phase behavior diagrams in the silicon nitride field are reviewed in this work, with emphasis on the Y-Si-A1-O-N system. This information is further used to make observations on the promising silicon nitride systems containing either highly refractory grain boundary phases or compatible matrix phases of desirable properties. Examples are provided to illustrate the advantage of such a basic approach to materials design. Hardness, toughness, strength at room temperature and elevated temperature and even sinterability can all be improved by adopting such an approach.

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