• Transactions of the Korean Society of Automotive Engineers
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• v.19 no.6
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• pp.90-96
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• 2011

In this study, the characteristic of fractured portion and shape on solder joints were investigated according to the thermal shock test for Automotive Application Component using Sn-3.0Ag-0.5Cu solder, which has a outstanding property as Lead-free solder. The value of pull and shear strength was decreased in principle after 432 cycles thermal shock test. In addition, fracture mode was verified by using EDS and SEM to observe fractured shape on the solder joints before and after thermal shock. In before thermal shock test, the fracture mode revealed typically solder layer's fracture mode. In after thermal shock test, we identified multiple fracture mode of the ductile and brittle fracture. Even though same composition of solder was used to experimental for estimating. the fracture mode varied on the fracture portion's height and the directional angles of shear strength. In conclusion, we identified that mechanical strength was affected on the solder layer's fracture mode.

• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.1
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• pp.68-77
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• 2013

This paper presents AUTOSAR-ready light software architecture (AUTOSAR-Lite), which is a light weighted version of the AUTOSAR, for automotive embedded control systems. The proposed AUTOSAR-Lite reduces overhead problems caused by the excessive standard specifications of AUTOSAR. Concurrently, AUTOSAR-Lite keeps advantages of AUTOSAR such as a scalability, re-usability, reliability, and transferability. The fundamental design of AUTOSAR-Lite is originated from the AUTOSAR standard. AUTOSAR-Lite is composed of three layers such as an application software, runtime environment, and basic software layer. The application software layer adopts component-based design methodology as AUTOSAR. The runtime environment layer integrates interfaces between application and basic software layers. In case of the basic software layer, restrictions of the module configurations and interfaces of basic software are minimized. In order to validate the feasibility of AUTOSAR-Lite, a software design result based on AUTOSAR-Lite software architecture for electronic throttle control (ETC) system is suggested.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.23 no.8
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• pp.611-616
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• 2010

This study investigated the characteristics of fracture behavior and mode on solder joints before and after thermal shock test for automotive application component using Sn-3.0Ag-0.5Cu solder, which has a outstanding property as lead-free solder. The shear strength was decreased with thermal cycle number, after 432 cycles of thermal shock test. In addition, fracture mode was verified to ductile, brittle fracture and base materials fracture such as different kind fractured mode using SEM and EDS. Before the thermal shock, the fractured mode was found to typical ductile fracture in solder layer. After thermal shock test, especially, Ag was found on fractured portion as roughest surface. Moreover, it occurred delamination between a PCB and a Cu land. Before thermal shock test, most of fractured mode in solder layer has dimples by ductile fracture. However, after thermal shock test, the fractured mode became a combination of ductile and brittle fracture, and it also could find that the fracture behavior varied including delamination between substrate and Cu land.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.24 no.12
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• pp.949-954
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• 2011

In this study, the characteristics and error ranges of the mechanical bonding strength were analyzed according to before and after thermal shock test for various chips of automotive application component using Sn-3.0Ag-0.5Cu solder. In the after thermal shock test, the mechanical bonding strengths tend to decrease, meanwhile decreasing rates of mechanical strengths were less then 12% at specimen's bonding area below 3.5$mm^2$, and were from 17 to 21% at specimen's bonding area above 12 $mm^2$. On the other hand, Specimen's mean deviation rates were about 5% at specimen's bonding area more than 12 $mm^2$. Inversely, at specimen's bonding area is less then 3.5 $mm^2$, mean deviation rates were increased to about 8%. It means that the smaller device size is, the larger mean deviation rate. In addition, error ranges and deviation rates of the mechanical bonding strengths may differ slightly depending on their bonding area. Furthermore, process conditions as well as method of mechanical reliability evaluation should be established to reduce the error ranges of bonding strength.

• International Journal of Automotive Technology
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• v.4 no.1
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• pp.21-30
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• 2003

In this paper a systematic test procedure for evaluation of road-induced noise of a vehicle and guidelines for each test are presented. Also, a practical application of the test procedure to a small SUV is presented. According to the test procedure, all the tests were performed to evaluate road-induced booming noise that is in low frequency range. First of all the information on characteristics of road-induced noise was obtained through baseline test. Coupling effects between body structure and acoustic cavity of a compartment were obtained by means of modal tests for a structure and an acoustic cavity. Local stiffness of joint areas between chassis system and car-body was determined by test for measurement of input point inertance. Noise sensitivities of body joints to operational forces were obtained through test for measurement of noise transfer functions. Operational deflection shapes made us analyze behaviors of chassis system under running condition and then find sources of noise due to resonance of the chassis system. Finally, Principal Component Analysis and Transfer Path Analysis were utilized to investigate main paths of road-induced noise. In order to evaluate road-induced booming noise exactly, all of tests mentioned above should be performed systematically.

• Journal of Korea Foundry Society
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• v.27 no.1
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• pp.20-23
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• 2007

• Transactions of the Korean Society of Automotive Engineers
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• v.15 no.2
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• pp.28-34
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• 2007

In design stage of vehicles, the application of virtual durability analysis techniques enables us to cut down the necessary time and cost to carry out various physical experiments. In this study, computer simulations of vehicle suspensions were carried out with DADS program including component flexibility, and the durability analysis of vehicle components was executed with MSC/Fatigue program using the load history obtained from vehicle dynamic simulation. Driving test of a vehicle was also carried out to obtain precise input data for the durability analysis, and the results of virtual durability analysis were compared to those of experiments.

• Transactions of Materials Processing
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• v.20 no.4
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• pp.279-283
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• 2011

Recently incremental sheet metal forming (ISF) has used widely in making prototypes and small-volume products in automotive industry etc. We apply the ISF to make a 1/4 sized automobile body-in-white. First, ISF tests for rectangular shaped cup have been performed to clarify the formability denoting the relationship between the component wall angle and maximum cup height of safe forming. Next, a CAD model for the automobile was designed and segmented into several components in order to accommodate the working space of the CNC machine we adopted and the formability of the sheet metal. Then, a CAM software was employed to generate the tool path for manufacturing wooden dies and all the small parts. Finally, the different parts were joined into a single component by laser welding after the ISF process. By using the ISF we successfully produced the 1/4 sized automobile body-in-white.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2005.05a
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• pp.188-191
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• 2005

Lower arm for automobile has been made in steel traditionally. Nowadays steel is being substituted fur aluminum to reduce weight of automobile. Widely applied production method of aluminum component has been casting processes or cast/forging processes. But casting or cast/forging processes have limits of application to parts which is required high strength durability like automotive component. In this research, hot forging process has been adopted to produce aluminum lower arm to ensure required mechanical properties. To reduce production cost, 2 pieces with 1 blow process was developed. Optimization and verification of hot forging process for aluminum lower arm was performed by computer aided engineering using finite volume methods.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.11a
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• pp.143-146
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• 2005

In modern automotive control modules, mechanical failures of surface mounted electronic components such as microprocessors, crystals, capacitors, transformers, inductors, and ball grid array packages, etc., are mai or roadblocks to design cycle time and product reliability. This paper presents a general methodology of failure analysis and fatigue prediction of these electronic components under automotive vibration environments. Mechanical performance of these packages is studied through finite element modeling approach fur given vibration environments in automotive application. Using the results of vibration simulation, fatigue lift is predicted based on cumulative damage analysis and material durability information. Detailed model of solder/lead joints is built to correlate the system level model and obtain solder strains/stresses. The primary focus in this paper is on surface-mount interconnect fatigue failures and the critical component selected for this analysis is 80 pin plastic leaded microprocessor.