Board level drop test method of components for handheld electronicproduc ts

2015 ◽  
Keyword(s):  
Author(s):  
Qiang Yu ◽  
Masato Fujita ◽  
Tsuyoki Shibata ◽  
Takayoshi Katahira ◽  
Masaki Shiratori

In recent years, mobile phones have been miniaturized, so electronic components with high I/O count have been changed from QFP/SOIC to BGA/LGA. However BGA/LGA tends to have weak reliability for drop impact, and the drop reliability needs to be improved. For that, board level drop reliability has an important role in order to evaluate drop reliability for electronic components excluding influence from phone mechanics. This study focuses on the characterization of the test methods using experimental test, strain analysis and FEM simulation. In this paper, board level drop test shows drop a fixture with a component assembled on PWB. The drop test using a fixture with a flat bottom lacked of repeatability of failed drop count, and it was improved by adding hemisphere at the center on fixture bottom to reduce the influence by variation of falling posture angle, and strain analysis and the drop experimental proved it, too. The deformations of the fixture influence the test results, because the deformation of fixture caused high stress on solder joints. For that, the method to exclude the influence of fixture deformation was studied, and it was found that the influence can be decreased by supporting condition of PWB with a free-sliding end or the new design of the fixture. On the other hand, the effect of height of drop, mass of fixture, and supporting condition on the drop test, can be thought as the acceleration factors for the dropping load conditions. The drop tests were done in many load conditions. The results were analyzed by strain analysis and FEM simulation. As a result, an accelerating ratio can be evaluated by predicting the effect of these factors, and effective dropping test can be conduct without increasing the dropping height exceedingly.


2011 ◽  
Vol 423 ◽  
pp. 26-30
Author(s):  
S. Assif ◽  
M. Agouzoul ◽  
A. El Hami ◽  
O. Bendaou ◽  
Y. Gbati

Increasing demand for smaller consumer electronic devices with multi-function capabilities has driven the packaging architectures trends for the finer-pitch interconnects, thus increasing chances of their failures. A simulation of the Board Level Drop-Test according to JEDEC (Joint Electron Device Council) is performed to evaluate the solder joint reliability under drop impact test. After good insights to the physics of the problem, the results of the numerical analysis on a simple Euler-Bernoulli beam were validated against analytical analysis. Since the simulation has to be performed on ANSYS Mechanical which is an implicit software, two methods were proposed, the acceleration-input and the displacement-input. The results are the same for both methods. Therefore, the simulation is carried on the real standard model construction of the board package level2. Then a new improved model is proposed to satisfy shape regular element and accuracy. All the models are validated to show excellent first level correlation on the dynamic responses of Printed Circuit Board, and second level correlation on solder joint stress. Then a static model useful for quick design analysis and optimization’s works is proposed and validated. Finally, plasticity behavior is introduced on the solder ball and a non-linear analysis is performed.


2021 ◽  
Author(s):  
Ryan Terpsma ◽  
Rika Wright Carlsen ◽  
Ron Szalkowski ◽  
Sushant Malave ◽  
Alice Lux Fawzi ◽  
...  

ABSTRACT Introduction The Advanced Combat Helmet (ACH) military specification (mil-spec) provides blunt impact acceleration criteria that must be met before use by the U.S. warfighter. The specification, which requires a helmeted magnesium Department of Transportation (DOT) headform to be dropped onto a steel hemispherical target, results in a translational headform impact response. Relative to translations, rotations of the head generate higher brain tissue strains. Excessive strain has been implicated as a mechanical stimulus leading to traumatic brain injury (TBI). We hypothesized that the linear constrained drop test method of the ACH specification underreports the potential for TBI. Materials and Methods To establish a baseline of translational acceleration time histories, we conducted linear constrained drop tests based on the ACH specification and then performed simulations of the same to verify agreement between experiment and simulation. We then produced a high-fidelity human head digital twin and verified that biological tissue responses matched experimental results. Next, we altered the ACH experimental configuration to use a helmeted Hybrid III headform, a freefall cradle, and an inclined anvil target. This new, modified configuration allowed both a translational and a rotational headform response. We applied this experimental rotation response to the skull of our human digital twin and compared brain deformation relative to the translational baseline. Results The modified configuration produced brain strains that were 4.3 times the brain strains from the linear constrained configuration. Conclusions We provide a scientific basis to motivate revision of the ACH mil-spec to include a rotational component, which would enhance the test’s relevance to TBI arising from severe head impacts.


2012 ◽  
Vol 134 (1) ◽  
Author(s):  
Hung-Jen Chang ◽  
Chau-Jie Zhan ◽  
Tao-Chih Chang ◽  
Jung-Hua Chou

In this study, a lead-free dummy plastic ball grid array component with daisy-chains and Sn4.0Ag0.5Cu Pb-free solder balls was assembled on an halogen-free high density interconnection printed circuit board (PCB) by using Sn1.0Ag0.5Cu solder paste on the Cu pad surfaces of either organic solderable preservative (OSP) or electroless nickel immersion gold (ENIG). The assembly was tested for the effect of the formation extent of Ag3Sn intermetallic compound. Afterward a board-level pulse-controlled drop test was conducted on the as-reflowed assemblies according to the JESD22-B110 and JESD22-B111 standards, the impact performance of various surface finished halogen-free printed circuit board assembly was evaluated. The test results showed that most of the fractures occurred around the pad on the test board first. Then cracks propagated across the outer build-up layer. Finally, the inner copper trace was fractured due to the propagated cracks, resulting in the failure of the PCB side. Interfacial stresses numerically obtained by the transient stress responses supported the test observation as the simulated initial crack position was the same as that observed.


2014 ◽  
Vol 936 ◽  
pp. 628-632 ◽  
Author(s):  
Guo Zheng Yuan ◽  
Xia Chen ◽  
Xue Feng Shu

The failure of plastic ball grid array under intense dynamic loading was studied in the project. This paper presents the drop test reliability results of SnPb flip-chip on a standard JEDEC drop reliability test board. The failure mode and mechanism of planar array package in the drop test was comprehensively analyzed. High acceleration dropping test method was used to research the reliability of BGA (ball grid array) packages during the free-drop impact process. The model RS-DP-03A drop device was used to simulate the falling behavior of BGA chip packages under the real conditions, The drop condition meets the JEDEC22-B111 standards (pulse peak 1500g, pulse duration 0.5 ms) when dropping from the 650mm height . In the testing, according to the real-time changes of dynamic voltage, the relationship between drop times and different phases of package failure was analyzed. With the dye-penetrated method and optical microscopy, it was easy to observe the internal crack and failure locations. The growth mechanism of the cracks in solder joints under the condition of drop-free was analyzed and discussed.


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