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.
The SnSbNi solder pastes were reflowed at 270°C and 280°C between the MvpLED chip and the AlN ceramic substrate, and then the SnSbNi solder joints were aged respectively at 200°C for 1h and at 250°C for 3h. The interfacial microstructure and constituents were investigated by SEM and EDS. After the reflow reactions, a thin layer of IMCs was formed at the chip/solder and solder/substrate interfaces,...
As the defects in the LED chip is an important factor affecting the properties of high-power LEDs, a new measurement system is proposed which can get nonradiative recombination defect densities of a LED chip quantification ally, and a new method for evaluation of LED's performance is introduced which based on the relationship model between nonradiative recombination defect and LED's aging property...
LED with many advantages such as high brightness, long-lifetime, and energy-saving has been successfully applied to various fields, especially on special lighting applications. At low temperatures, LED is more uniform in illumination and has a higher luminous efficiency, which is regarded as the next generation refrigeration system lighting. As well as in some cold regions, LED has also become the...
LED lighting becomes the forth generation green lighting. However, in terms of LED development and large-scale application, the reliability of LED has become one of the technical bottlenecks. This paper carried out the research on the thermal-humidity reliability of high power LED module by the means of experiment and simulation, which mainly aims at the reliability problems existed in high power...
Improving the reliability of solder joints is an urgent issue to guarantee the quality of surface assembly products. The size of components and pitches on the circuit board differs from each other which leads to the size of solder joints variation one by one. In this study, the size effect of solder powder on Sn-3.0Ag-0.5Cu solder joints in high density LED display packaging was investigated. The...
Thermal characteristic of light emitting diodes is one of primary reliability parameters. In this paper, the thermal resistances of different kinds of blue and white high power LEDs are measured by the forward voltage based method. The relationships between thermal resistance and heat time at measurement currents 1mA, 5mA and 10mA are obtained respectively. The results show that there is optimum heat...
In this paper, an improved method to investigate the reliability of solder joint between High-power LED chip and heat sink is presented. The power cycling is carried out through the switching on and off of the current stress. The optical and electrical characteristics do not degrade apparently. Electrical method is used to measure the thermal resistance of high-power LED which increases from 15.81°C/W...
Low temperature sintered nano-silver paste becomes a potential alternative in green electrical packaging because of its higher thermal and electrical conductivity than conventional solders. It can be used for connected chips that require high temperature operation, such as high power LED and power electronics modules, etc. During service, alternating shear strain, even thermal fatigue failure will...
This paper uses FTA (Fault Tree Analysis) with FMEA (Fault Mode Effect and Analysis) to do the study on reliability of low voltage apparatus. Establishing the fault tree is the most important step in using fault tree analysis. The validity of the tree model will have a great impact on the study result. The combination of the two analysis method can give a full-scale and detailed analysis of the product...
Heat dissipation for packaging high-power light-emitting diodes is critically important to performance and reliability of LED lighting modules. The first thermal interface encountered by the heat flow is a die-attach material between the diode chip and its substrate. In this study, three different types of die-attach materials were used to construct 1-Watt GaN LED single-chip modules: a silver epoxy...
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.