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.
Friction stir spot welding (FSSW) is a solid-state welding process used for joining similar and dissimilar materials. AA1060 and C11000 sheets were joined using different process parameters and tool geometries. The presence of a copper rings also called hooks were observed in all the produced spot welds and their length increases with the tool shoulder plunge depth; whereas the spot welds produced...
In 1991, a game changing technique was introduced into the metal joining community. Patented in 1991 by The Welding Institute, the Friction Stir Welding (FSW) process has since transformed the way metal joining is being done. Since then, many industries have come to embrace the new joining technology due to its ease of operation and other numerous advantages it offers. Aside from the ease with which...
Dissimilar metal joining methods are essential for the manufacturing of a various structures and parts in the industries. Friction stir spot welding process was performed on 3 mm thick AA1060 and C11000. This paper presents the results on the microstructure, chemical analysis and electrical resistivities of the produced joints. The microstructure showed a contrast between the two different materials...
This paper presents the topic of manufacturing the stator winding for small induction motors of aluminium instead of copper. The aspect of replacing the material is presented from the perspective of the producer. It is important to obtain a new motor with the same characteristics and the same energy efficiency while decreasing conductor material price and thus the price per motor unit. For these purpose...
Ultrasonic welding is one of the mainstream joining technologies for an automotive battery pack where battery cells are welded mostly in series with bus-bars on interconnect circuit boards in battery electric vehicles (BEV). Mathematical simulations, such as Finite Element Analysis, have been used to simulate the ultrasonic welding for process and joint quality optimizations. Since friction-generated...
Through long global experience and test results it has been described that the aluminium wound large distribution transformers are equally good like copper wound transformers. Performance and life of transformers are same and also the parameters can be maintained identical like copper wound transformers. There will be nominal dimension increase which are normally not critical issue. The biggest advantage...
Micro-scale wear testing of soft materials, such as copper, aluminum, magnesium alloy, AISI10045 steel et al., was investigated with multifunctional micro-wear tester by self-development. And it was also compared with that of Ni60B coating and TiN coating with higher hardness. Roughly annular regions emerged in the abrasion scars were analyzed. Problems associated with the measurement of abrasion...
This paper presents the results of a numerical analysis on the electrical interconnect options of a Power QFN (PQFN) package, to explore and compare the RDS(ON) performance at DC condition. The modeling involves the PQFN 5mm × 6mm package which initially uses Aluminum wire bonds for interconnection. Competition in the market in terms of better electrical performance packages challenge semiconductor...
In long term reliability evaluations of Spansion memory products built using copper (Cu) wire bonding in lieu of gold (Au) wire for package-to-die interconnection, results indicated acceptable reliability performance of the copper-aluminum (Cu-Al) bond. Some differences, however, were observed when compared to gold-aluminum (Au-Al) bonds used as a control. In order to determine if these differences...
In this paper, changes of thermal conductivity of paraffin mixtures joined different percentages of aluminum, copper, silicon powder were stuPdied. Feasibility of adding these three kinds of powders into paraffin to enhance paraffin's thermal properties was studied, as well as the influence of different addictives on paraffin's phase-change temperature and latent heat. The results showed that adding...
As the popularity of Cu wire bonding continues to grow, it inspires more packages to introduce Cu bonding to enhance product electrical, thermal & reliability performances at the same time enjoying unit package cost down. Risk of damaging the bond pad structure underneath in Cu bonding is always a challenge especially bonding on very thin bond pad structure with large wire size. 43 μm Cu wire...
The size of IC device has been reduced resulting from the advancement of silicon fabrication technology in reducing the transistor gate length. For wire bonded devices with high IO count, the final die size is principally determined by the size and layout configuration of the IO cells and wire bond pads. Traditional design of wire bond pads would consist of a top metal layer with no active circuitry...
Gold (Au) and aluminum (Al) has been used for wire bonding interconnect for decades. Recently, copper (Cu) is used in high temperature applications and general cost down approaches. Cu induces a higher stress on the bond pad and underlying structure due to its inherent hardness value. In this paper, we will investigate silver (Ag) as fairly new alternative for bonding wire. An overlap in terms of...
Summary form only given. This paper will describe copper wirebonding on Cu-Ni-Pd bond-pad and leadframe in QFN packages using thicker wires i.e 1.3 & 2.0mil wires. The paper introduces bonding and reliability challenges with Copper wire on Al bond pads as experienced by many Process Development Engineers. TI analog devices which mainly used BOAC dies using Cu-Ni-Pd bond-pads and copper-wire combination...
High gold prices have led to renewed interest in replacing gold with copper in existing packages and new packages in order to save costs. Although reliability is often cited as a reason for using copper, the main driving force for its use is undoubtedly cost. Perceptions that copper wire is more reliable are based on the notion that the intermetallics grow more slowly and that thinner intermetallics...
The mechanism of wirebonding bondability for ultra thin Copper wire is described in this research. Two major analyses are conducted in the present paper. In the first, the characteristic of heat affected zone (HAZ) and free air ball (FAB) on thin Copper (Cu) wire have been carefully experimental measured. Thin film interfacial micro-tribology behavior between Cu FAB and Al pad is examined by Atomic...
The relation between minimum thickness of cut (MTC) and the extreme machining accuracy attainable for a specific cutting condition by Atomic Force Microscope (AFM) has been discussed. A mechanical model was used to describe qualitatively the minimum thickness of cut during nanometric cutting process. Mechanical response of aluminum and copper on nanoscratching has been studied. The analysis of the...
Recently, the dimensions of the flip-chip solder bumps reduce to about 20-30 micrometers, also known as "micro-bumps" sandwitched between two Si chips. In such a structure, electromigration and thermomigration behaviors in the micro-bumps are not clear now. In this study, the temperature map distribution of Al traces and Al pads in CoC and C4 structures during current stressing was directly...
When the flip-chip packaging has been moving to the lead-free, fine-pitch and high-current-density packaging, the flip chip with copper-pillar-bump interconnects can provide a solution to this need. However, this package during the thermal cycling test (TCT) still suffers the reliability problems such as delamination at the Cu low-k materials or at the interface between the UBM (under bump metallurgy)...
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.