Low cycle fatigue of surface-mounted chip-carrier/printed wiring board joints

1989 ◽  
Vol 12 (4) ◽  
pp. 473-479 ◽  
Author(s):  
H.D. Solomon
Keyword(s):  
Low Cycle Fatigue ◽  
Cycle Fatigue ◽  
Printed Wiring Board ◽  
Chip Carrier ◽  
Wiring Board

Influence of Temperature on the Fatigue of CC/PWB Joints

1990 ◽  
Vol 33 (1) ◽  
pp. 17-25
Author(s):  
Harvey Solomon
Keyword(s):  
Fatigue Life ◽  
Low Cycle Fatigue ◽  
Hysteresis Loops ◽  
Cycle Fatigue ◽  
Printed Wiring Board ◽  
Influence Of Temperature ◽  
Joint Resistance ◽  
Influence Of Temperature On ◽  
Chip Carrier ◽  
Wiring Board

This is a study of the low cycle fatigue of chip carrier/ printed wiring board joints tested at -55° C (-67° F) and 125° C (257° F). It is contrasted to a previous study where the joints were tested at 35° C (95° F). The behavior at 35° C and 125° C was the same. Differences were noted, however, at -55° C. The hysteresis loops were distorted. The slopes of the displacement vs. fatigue life curves were slightly lower and the fatigue lives were longer. These differences were especially significant when the change in joint resistance was used to define failure.

Fatigue Assessment of Solder Bumps on Board Assemblies Affected by PWB Warpage

2007 ◽  
Vol 4 (1) ◽  
pp. 37-44 ◽  
Author(s):  
Wei Tan ◽  
I. Charles Ume
Keyword(s):  
Solder Bump ◽  
Low Cycle Fatigue ◽  
Cycle Fatigue ◽  
Fatigue Reliability ◽  
Printed Wiring Board ◽  
Solder Bumps ◽  
Plastic Ball ◽  
Different Types ◽  
Free Solder ◽  
Projection Moire

Out-of-plane displacement (warpage) has been a major reliability concern for board-level electronic packaging. Printed wiring board (PWB) and component warpage results from CTE mismatch among the materials that make up the PWB assembly (PWBA). Warpage occurring during surface-mount assembly processes and normal operations may lead to severe solder bump failures. In this research, the effect of PWB warpage on the low cycle fatigue of the solder bumps in plastic ball grid array (PBGA) packages was studied. Finite element modeling (FEM) was used for the strain-based life prediction of solder bumps on board assemblies. In this paper, 3-D models of PWBAs with varying board warpage were used to estimate the solder bump fatigue life for different types of PBGAs mounted on PWBs. In order to improve the accuracy of FE results, the projection moiré method was used to measure the initial warpage of PWBs, and this warpage was used as a geometric input to the FEM. The PWBAs with known PWB warpage were modeled to determine the influence of various levels of initial PWB warpage on the low cycle fatigue failure of solder bumps. The effect of different types of PBGAs with varying locations on solder bump fatigue was studied. Both Sn-Pb and lead-free solder materials were used in this study. The FE models were validated with experimental results obtained using the projection moiré technique. The FE results showed that the initial PWB warpage has significant a effect on the fatigue reliability of solder bumps in PBGA packages.

The Influence of the Cycle Frequency and Wave Shape on the Fatigue Life of Leaded Chip Carrier Printed Wiring Board Interconnections

1993 ◽  
Vol 115 (2) ◽  
pp. 173-179 ◽  
Author(s):  
H. D. Solomon
Keyword(s):  
Fatigue Life ◽  
Hold Time ◽  
Shape Effect ◽  
Printed Wiring Board ◽  
Wave Shape ◽  
Maximum Displacement ◽  
Cycle Frequency ◽  
Chip Carrier ◽  
Plastic Displacement ◽  
Wiring Board

This study employed different cycle frequencies, to determine the influence of cycle frequency on the fatigue life of leaded chip carrier printed wiring board (LCC/PWB) interconnections. Real LCC/PWB interconnections were mechanically cycled at 35°C or 125°C. The cycle frequency was varied by varying the ramp loading and unloading rates or by introducing hold times. Tests were run with equal hold times at the maximum and minimum displacements or only at the maximum displacement. The use of slower ramp cycling or the introduction in the hold times increased the plastic displacement and this decreased the fatigue life. This plastic displacement increase was corrected for, to unveil the underlying material response. The corrected data was similar to that observed in previous tests on simple, single, solder joints, where the plastic strain was kept constant while the cycle frequency was reduced. At 125°C there was a small influence of wave shape, with maximum displacement hold time tests showing the shortest fatigue lives and symmetric (maximum and minimum) hold time tests showing the longest fatigue lives. The fatigue lives of the tests run with ramp cycling were intermediate. This wave shape effect is relatively small, especially compared to the large overall influence of the cycle frequency.

Effect of Texture and {10-12} Twin on the Low Cycle Fatigue Properties of Rolled AZ31 Mg Alloy

2013 ◽  
Vol 51 (5) ◽  
pp. 325-332 ◽  
Author(s):  
Sung Hyuk Park ◽  
Seong-Gu Hong ◽  
Chong Soo Lee ◽  
Ha Sik Kim
Keyword(s):  
Low Cycle Fatigue ◽  
Mg Alloy ◽  
Fatigue Properties ◽  
Cycle Fatigue ◽  
Az31 Mg Alloy

Fracture Surface in Low Cycle Fatigue of HA-188 Cobalt Base Alloy at High Temperature

1978 ◽  
Vol 27 (292) ◽  
pp. 99-103 ◽  
Author(s):  
Kiyoshi KITA ◽  
Masanori KIYOSHIGE ◽  
Masatake TOMINAGA ◽  
Junzo FUJIOKA
Keyword(s):  
High Temperature ◽  
Fracture Surface ◽  
Base Alloy ◽  
Low Cycle Fatigue ◽  
Cycle Fatigue ◽  
Cobalt Base Alloy ◽  
Cobalt Base

Features of the kinetics of cyclic elastoplastic deformation diagrams at dwells in cycles and superimposition of variable stresses on them

2020 ◽  
Vol 86 (12) ◽  
pp. 46-53
Author(s):  
M. M. Gadenin
Keyword(s):  
Experimental Data ◽  
Elastoplastic Deformation ◽  
Low Cycle Fatigue ◽  
Cycle Fatigue ◽  
Loading Cycle ◽  
Additional Variable ◽  
Dynamic Creep ◽  
Variable Stresses ◽  
Kinetics Of ◽  
Deformation Diagrams

The goal of the study is determination of the regularities of changes in cyclic strains and related deformation diagrams attributed to the existence of time dwells in the loading modes and imposition of additional variable stresses on them. Analysis of the obtained experimental data on the kinetics of cyclic elastoplastic deformation diagrams and their parameters revealed that in contrast to regular cyclic loading (equal in stresses), additional deformations of static and dynamic creep are developed. The results of the studys are especially relevant for assessing the cyclic strength of unique extremely loaded objects of technology, including nuclear power equipment, units of aviation and space systems, etc. The experiments were carried out on the samples of austenitic stainless steel under low-cycle loading and high temperatures of testing. Static and dynamic creep deformations arising under those loading conditions promote an increase in the range of cyclic plastic strain in each loading cycle and also stimulate an increase in the range of elastoplastic strain due to active cyclic deformation. At the same time the existence of dwells on extrema of stresses in cycles without imposition of additional variable stresses on them most strongly affects the growth of plastic strain ranges in cycles. Imposition of additional variable stresses on dwells also results in the development of creep strains, but their growth turns out to be somewhat less than in the presence of dwells without stresses imposed. The diagrams of cyclic deformation obtained in the experiments are approximated by power dependences, their kinetics being described in terms of the number of loading cycles using corresponding temperature-time functions. At the same time, it is shown that increase in the cyclic plastic deformation for cycles with dwells and imposition of additional variable stresses on them decreases low cycle fatigue life compared to regular loading without dwells at the same stress amplitudes, moreover, the higher the values of static and dynamic creep, the greater decrease in low-cycle fatigue life. This conclusion results from experimental data and analysis of conditions of damage accumulation for the considered forms of the loading cycle using the deformation criterion of reaching the limit state leading to fracture.

Damage accumulation near a hole under low cycle fatigue proceeding from measurements of local deformation response

2020 ◽  
Vol 86 (10) ◽  
pp. 46-55
Author(s):  
S. I. Eleonsky ◽  
Yu. G. Matvienko ◽  
V. S. Pisarev ◽  
A. V. Chernov
Keyword(s):  
Stress Intensity Factor ◽  
Stress Intensity ◽  
Intensity Factor ◽  
Damage Accumulation ◽  
Stress Ratio ◽  
Low Cycle Fatigue ◽  
Accumulation Process ◽  
Stress Range ◽  
Cycle Fatigue ◽  
Deformation Response

A new destructive method for quantitative determination of the damage accumulation in the vicinity of a stress concentrator has been proposed and verified. Increase of damage degree in local area with a high level of the strain gradient was achieved through preliminary low-cycle pull-push loading of plane specimens with central open holes. The above procedure is performed for three programs at the same stress range (333.3 MPa) and different stress ratio values 0.33, – 0.66 and – 1.0, and vice versa for two programs at the same stress ratio – 0.33 and different stress range 333.3 and 233.3 MPa. This process offers a set of the objects to be considered with different degree of accumulated fatigue damages. The key point of the developed approach consists in the fact that plane specimens with open holes are tested under real operation conditions without a preliminary notching of the specimen initiating the fatigue crack growth. The measured parameters necessary for a quantitative description of the damage accumulation process were obtained by removing the local volume of the material in the form of a sequence of narrow notches at a constant level of external tensile stress. External load can be considered an amplifier enhancing a useful signal responsible for revealing the material damage. The notch is intended for assessing the level of fatigue damage, just as probe holes are used to release residual stress energy in the hole drilling method. Measurements of the deformation response caused by local removing of the material are carried out by electronic speckle-pattern interferometry at different stages of low-cycle fatigue. The transition from measured in-plane displacements to the values of the stress intensity factor (SIF) and the T-stress was carried out on the basis of the relations of linear fracture mechanics. It was shown that the normalized dependences of the stress intensity factor on the durability percentage for the first notch (constructed for four programs of cyclic loading with different parameters), reflect the effect of the stress ratio and stress range of the loading cycle on the rate of damage accumulation. The data were used to obtain the explicit form of the damage accumulation function that quantitatively describes damage accumulation process. The functions were constructed for different stress ratios and stress ranges.

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