The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Molecular dynamics (MD) simulations were carried out to study the mechanical properties of co-continuous Al/SiC nanocomposites under tensile loading. Three cases of different models were implemented to investigate the influence of volume fraction (Vf) of SiC, thickness of SiC skeletons and shape of Al nanowire on the mechanical properties of the nanocomposites. It is found that the ultimate strength...
Solder is widely used in electronic packaging to connect die and substrate in die attach process. It is important to get a uniform solder distribution to provide good electrical conductivity, mechanical support as well as excellent thermal properties for packages, especially for power packages with high current densities. While nonuniform solder distribution would emerge when die moves and tilts in...
Ultrasonic heavy aluminum wire bonding whose wire diameter is greater than 100 microns has been the dominant interconnection technology in IGBT modules to implement the electrical connection among chips, DBC substrates and electrode terminals. During the switching on/off operation, the stress concentrates in the bond wire induced by the coefficient of expansion (CTE) mismatch between Al wire and silicon...
By using the finite element thermal analysis method, the mode of the structure coupling analysis of the macro-micro motion platform is established, and the connecting frame and the thermal characteristic of the connecting frame and the flexible hinge platform is analyzed. It is found that the deformation amount of the connecting frame and the flexible hinge increases at the field load condition with...
This study grew high quality vertically-aligned InGaAs quantum dots (QDs) on a GaAs (001) substrate by using the molecular beam epitaxy system. The GaAsSb/AlGaAsSb composite overgrown layer was adopted to cap on InGaAs QDs for improving the dot size uniformity. From the experimental results, the Sb-contained overgrown layer was observed to reduce the In-Ga intermixing and contribute to the enhancement...
Graphene sheet (GS) is a two-dimensional (2D) material with extremely favorable mass sensor properties. In this paper, a linear elastic 2D plate model is applied to study the potential of a nanoscale mass sensor on individual GS. The simulated natural frequency was compared with the results obtained from the Rayleigh's energy method. The effects of the attached mass, aspect ratio, and the layer number...
Graphene sheet (GS) is a two-dimensional (2D) material with extremely favorable mass sensor properties. In this paper, a linear elastic 2D plate model is applied to study the potential of a nanoscale mass sensor on individual GS. The simulated natural frequency was compared with the results obtained from the Rayleigh's energy method. The effects of the attached mass, aspect ratio, and the layer number...
In this paper, a multi-sensor system in package (SiP) is designed for the safety monitoring of the heavy machinery. The multi-sensor is made up of several parts, including strain gauge array, acceleration sensor, temperature sensor, and a pair of ultrasonic detector and actuator. Strain gauge array in a certain pattern is used to monitor the strain and stress level at some critical positions of the...
Carbon nanotubes (CNTs) without any defects show particular promise for technological applications in the diverse fields of chemistry, electronics, engineering, and reinforced composite structures. Due to the unique high strength and low specific weight, CNTs can be used as exceptional stiff fibers for nanocomposites. Some CNTs have been also acted as probes in scanning probe microscopy. A variety...
With the current trend of cheaper, faster, and better electronic equipment, it has become increasingly important to evaluate the package and system performance very early in the design cycle using simulation tools [1]. Many studies have shown that the profile of temperature has a great impact on solder joint reliability. Undergoing the different temperature profile will get a different solder joint...
Flip-chip packaging on organic substrate has been used widely as a promising package technology for the next generation of electronic devices. However, due to its numerous interfaces (i.e. die/passivation, passivation/underfill, underfill/solder mask, and solder mask/circuit board), it is more susceptible to a variety of complexworking and testing environments, delamination can easily take place in...
Reliability problems heavily hinder light-emitting diode (LED), especially high brightness LED, from developing rapidly and putting into mass production. One of the most important reasons is that it has so many interfaces which are always the weakest places. LED chip's working temperature is about 90°C and the high mismatch of coefficient of expansion of different materials can inevitably cause failures,...
In this paper, the failure mechanisms of the direct bonding copper (DBC) substrate under the condition of temperature cycling are studied. The cyclic temperature considered ranges from −40°C to 200°C. Furthermore, finite element method is used to optimize the DBC substrate structure in order to reduce the thermal stress and improve the reliability and fatigue life of power modules. Various factors...
Due to its many advantages over traditional 3D packaging technology, through silicon via (TSVs) is being widely used. However, there are still a variety of obstacles hindering it from being developed rapidly. One of them is the huge thermal stress induced by big CTE mismatch between silicon and copper, which would even induce interfacial delamination. In this paper, thermal stress is evaluated first...
Impact behaviors of high-power LED are essential due to the possible poor adhesion of interfaces and should be studied. In this study, the analysis of dynamic response for high-power LED module under impact load is conducted with simplified theoretical analysis, experimental testing and numerical simulation. A self-made microelectronics drop impact tester is established. Then reliability performances...
Currently, most gallium nitride based light emitting diodes (LEDs) are fabricated with polar c-plane [0001] direction. This orientation of gallium nitride has a large polarization electric field. Therefore, the device performance is adversely affected by strain induced piezoelectric polarization. The strain affects crystalline quality as well as optical and electrical properties of LED epitaxial film...
In this paper, thick film resistors (TFRs) on alumina substrate for strain sensor applications have been developed and evaluated. Thick film technology based ceramic pressure sensors (CPS) are fabricated by screen printing and firing four TFRs on a machined circular diaphragm and then the TFRs are connected in a Wheatstone bridge configuration. Finite element method (FEM) is used to optimize structural...
When one-dimensional single atom chain was placed at the center of single wall carbon nano-tube (SWCNT) along the axis, and using the molecular dynamics simulation, the mechanical strength of a single-walled could be obtained in terms of the stress-strain curve. At this temperature of 0K, the ultimate stress of a SWCNT with one-dimensional single atom chain was higher than that of a SWCNT without...
As a newly lighting source, high power white light emitting diodes (LEDs) have many excellent performances and begin to be widely used. The LED street light fixture is one of the most typical and popular applications, which is studied and developed worldwide. However, those studies mainly focused on its light efficiency, light pattern, color temperature, and so on, few concentrated on the reliability...
Thick film technology based sensing elements are becoming a hot research in recent years and the study of their failure modes is badly needed. In this paper, the failure modes of the bonding strength between the 1.4016 stainless steel (SS) substrate and the dielectrics are investigated. Experimental results show that residual stress, surface roughness and cleanness of the diaphragm in the 1.4016SS...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.