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Increasing I/O counts have led to ever decreasing cross sectional contact areas or, by default, an increase in solder performance expectations. A recognized measure of solder joint integrity is gained through High Speed Shear testing, (HSS). This article will statistically evaluate the solderability of the dominant final finishes with reference to some real life variables. The only skew is that only...
Sn-3.0Ag-0.5Cu lead-free solder, PCB copper clad laminate and copper thin film substrate were used as experimental materials and the Cu/SAC305/Cu interconnection plate-level structure micro-solder joint was prepared by pulsed hot-pressing welding test. The author aimed at investigating the pulse welding time, pulse welding temperature and welding pressure which influence on the microstructure of solder...
In order to study the electromigration characteristics of the butting solder joint in microelectronic packaging devices, this paper designs a Cu/Solder/Cu electromigration experiment to observe the change of the microstructure of the interface by scanning electron microscopy (SEM). It is found that the evolvement of the IMC at anode follows a parabolic growth rule under the condition of electric current...
With the development of high density electronic packaging and surface mount assembly, fine pitch package or micro BGA are facing challenges such as miniaturization, high density and assembly problems due to the fine pitch and fine area array assembly limitation. Most fine pitch packages' pitch limited in around 0.3mm pitch. If pitches are smaller than this limitation, the manufacture of packages'...
The following paper will sketch a novel method of how to avoid lead in the module and at the same time enhance the module's efficiency with Light Capturing Ribbons (LCR). Additionally, the new process will show a way to reduce the silver content of crystalline PV modules. The key idea is the application of conductive adhesives. The main result of the project was to prove the ageing behaviour compared...
Finite Element simulations are often used to study the reliability of solder joints subjected to thermal cycling. Packaging configurations are becoming more complex to accommodate better functionality and performance. Increased complexity leads to several challenges for FE models including difficulties modeling thin layers and interfaces, as well as keeping the total numbers of nodes and elements...
This study was aimed at quantifying critically relevant topics about the influence of intermetallic compounds (IMC) within power electronics reliability such as the influence of soldering profile on the growth rate of IMC in large area solder joints, estimation of IMC thickness during non-isothermal ageing and the impact of IMC thickness on reliability. To this end, test samples were soldered using...
Mechanical properties of solder joints have influence on reliability of electronic products. Therefore the knowledge of the mechanical behavior of solder joints is very important. This article deals with comparison of mechanical properties of solder joints prepared with conventional soldering methods and ultrasonic soldering methods. Material for samples preparation was based on two PCB (material...
The number of in-vehicle power devices has been increasingly for motor controlling purposes. Power device packages should ideally be small and easy to mount. We have developed a small power module by assembling several power devices sealed with molding resin. Two new techniques were used to produce this module: one was the use of copper clips for high-current wiring, and the other was low-cost soldering...
QFN packages gained popularity among the industry due to its low cost, compact size, and excellent thermal electrical performance. Although PCBs are widely used for QFN packages in handheld devices, some customers require it for heavy industrial application demanding thicker PCB. When an electronic device is turned off and then turned on multiple times, it creates a loading condition called power...
Soldering of copper interconnects at ∼220 °C induces residual stresses in the crystalline silicon solar cells. These residual stresses may become detrimental in the context of thinner silicon cells (<180μm) causing cracking, performance loss and failures. In such a scenario a systematic evaluation of these residual stresses considering realistic material properties is required to assess the risk...
For several years, an approach to use fine-pitch flip chip package (<150um) with copper pillar/ microbump is for the realization of 2.5D/3D packages of higher density and performance enhancement. Generally, flux is widely used to clean the surfaces to be soldered for good wetting and form reliable joints. The upcoming concerns about fluxes are clean-ability for fine-pitch package, voiding and compatibility...
Recently, copper wires have been attracting much attention for LSI (Large Scale Integration) bonding because of its excellent mechanical and electrical properties, and low material cost. On the other hand, the end of these wires are usually joined to the pads or through-holes on the printed circuit board, and lead-free soldering is one of the popular bonding methods. Since the solders are weaker than...
A method to observe oxide layer states with an ellipsometer in real-time and the relationship between solder wettability and remaining oxide layer thickness are reported in this paper. An experiment system is constructed with a spectrum ellipsometer and a vacuum chamber which has a port to introduce formic acid gas to observe the copper oxide layer reduction process by formic acid in real-time. The...
Function failure was found successively in one type of smart remote controls when using a period of time. With preliminary investigation by electric circuit, low resistance was found between the neighboring pins on failure sample which connected with flexible printed board and rigid printed board, but the pins on good sample were insulated with the others. After peeling off the flexible printed board,...
Soldering of packaged electronic components using industry standard Sn-Ag-Cu (SAC) lead-free solders on low-cost foils, which are often the substrate of choice for flexible electronics, is challenging. This is mainly originating from the fact that the reflow temperatures of these solder alloys are normally higher than the maximum processing temperature of the low-cost flex foils. To enable component...
In this paper, we studied the current carrying capacity of solder joints in the Copper Column Grid Array (CuCGA) by means of finite element method (FEM). The current carrying capacity of solder joints can be reflected by the peak value of the temperature and current density. And the solder fillets were the critical region in the entire CuCGA. Therefore, the paper mainly studied the influence of the...
CSP LED packages are soldered directly on printed circuit bords (PCB). Voids in the solder joints and tilting of the LED package influence the reliability of the LED module and need to be inspected directly after assambl. By X-Ray and optical 3D inspection combined with transient thermal analysis the required quality of the assembly can be insured. The impact of tilting on the thermal and thermomechanical...
The reason for the PCB warpage is the mismatch of the thermal expansion coefficient between different components materials, which leads to stress in the interconnected solder joints of components. In this paper, we used the finite element method (FEM) to investigate the PCB warpage in the CuCGA interconnection structure in the process of thermal cycle and the influence of copper columns aspect ratio...
In the push for thinner packages for applicationprocessors, baseband processors, and other devices, EmbeddedTrace Substrates (ETS) have found quick adoption in themicroelectronics packaging industry. ETS offer several benefitsover conventional cored substrates, such as dielectric layerthickness reduction, layer count reduction, and lowermanufacturing costs. In parallel, copper pillar interconnectshave...
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