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With the rapid growth in the mobile industry, Package-on-Package (PoP) technology has been widely adopted for the 3D integration of logic and memory devices within mobile handsets and other portable multimedia products. The PoP solution offers significant advantages, including increased density through stacking logic and memory devices in the same formfactor and a high degree of flexibility for variable...
Defect of SAC305 large-size BGA components attached with SnPb solder was analyzed by metallographic examination, and the faulty welded joint was found at the center position of the component. In order to explain the failure mode, reflow process simulation on assembled PCB board was carried out by ANSYS, and the temperature distribution was deeply studied. It is shown that there a obvious difference...
In this paper, a failure analysis on ball grid array (BGA) solder joints is revealed with the aid of scanning acoustic microscope (SAM), optical microscope (OM), scanning electron microscope (SEM) and strain tester. By employing both the nondestructive analysis and destructive analysis, it was found that crack of several BGA solder joints caused the failure of the printed circuit board assembly (PCBA)...
The objective of this paper is to investigate the effect of rapid thermal cycling on microstructure and optical property (luminous flux and luminous efficiency) of high power light emitting diode (LED) by thermal fatigue testing from −40 to 125. Under an application of thermal fatigue device as a heating source, the specimens that were being non-operating and thermal fatigue testing in the experiment...
0.35mm fine pitch wafer level chip scale package (WLCSP) has been developed by NCAP for portable electronic applications. It can provide 196 pin counts in 5mm × 5mm package body size. This paper reports the development work of WLCSP and the package level and board level reliability study including thermal cycling and drop test. The technology is evaluated using a 5mm × 5mm test vehicle with 0.35mm...
Surface mount technology solder joint reliability issue is the impact on the performance of surface mount components and the service life of the key problems, the main factors which influence the reliability of including the internal quality of welds, mechanical properties and loading conditions of solder joints. This paper mainly focused on the pins' failure of Ceramic Small Out-Line Package (CSOP)...
As the electronic packaging and fabrication industries for solar PV cells assembly or panels are making endeavours in using Pb-free solder joints, the reliability of these joints can be taken as an important research topic. Among several aspects, the control of void formation, growth and evolution in lead-free Sn-based solders can be achieved if the underlying mechanism for such phenomena can be modeled...
Recently, developing thick interfacial intermetallic compound layers with rough morphology has been detrimental to the long term solder joint reliability for lead free solders currently. A novel method has been developed to control the morphology and growth of intermetallic compound layers between pure Sn solder ball and Cu substrate by doping flux with amount of 2wt.% metallic Cu nanoparticles. And...
Three-dimensional structure has been achieved using interlayer connecting technology with double-side solder bump and the lifetime of the solder joints under thermal shock test has been forecasted by finite element method. The simulation result presents that the stress at the interface between 0.76mm solder bump and PCB is evidently higher than that in other places. The interface between 0.76mm solder...
Due to the promotion of the globalization of environmental protection process, some high reliability requirements of electronic products have to be passive to the backward compatible soldering process. Compared to the traditional Sn-Pb soldering process and the current mature Pb-free soldering process, the backward compatible soldering process is faced with a smaller process window and a higher process...
The effect of anisotropy in β-Sn grain on electromigration (EM)-induced failure mechanism of the Ni/Sn-3.0Ag-0.5Cu/Ni-P solder interconnects was in situ investigated. Sn grain orientation was a crucial factor in dominating the EM behavior. When the c-axis of Sn grain was parallel to the electron flow direction, a larger EM flux was induced, resulting in an excessive dissolution of Ni at the cathode...
This paper mainly studies the influence of loading rate on the shear mechanical properties of BGA solder joints, four kinds of solders (SAC305, SAC0307, SAC0307-0.07La and SAC0307-0.07La-0.05Ce) were prepared by means of experiment. The results show that the shear strength of the solder joints in the single board structure was increased with the increase of shear rate, but the shear strength of high-silver...
Sintered silver has received a great deal of recent attention as a high-temperature die-attach material. A detailed study of the sintered silver for bonding insulated gate bipolar transistor dies is reported. The purpose was to compare the reliability between sintered silver and Sn-3Ag-0.5Cu (SAC305) solder joints. It was found that the sintered silver had a porous and crack-free structure. And compared...
We report the effects of multiple reflow cycles on the reliability of Sn-Sb solders. Reflow soldering technology was used to prepare the Sn-Sb joints after 1 reflow cycle, 2 reflow cycles and 3 reflow cycles. We found that the intermetallic compound layers became thicker and denser with the reflow cycle increased. And the samples here had good bonding quality with only a few voids. After 600 thermal...
In order to verify the reliability of the tin-lead eutectic solder joint for providing references for the development of product working in the cryogenic environment, several samples of the wire and the transition piece were soldered with the tin-lead eutectic solder. The appearance, tensile strength, metallographic, microstructures and thickness of the alloy layer of the joints of samples were observed...
Thermal ageing of micro-porous sintered silver was examined under high temperature exposure. Silver sinter paste was printed in a shape of a tensile specimen on a Cu substrate, and was sintered at 250 °C for 1 h in air with no pressure. Specimens were exposed for 0, 50, 500, and 1000 h at 250 °C. Tensile strength was obtained at each ageing stage at a strain rate of 1.0×10−5/s. The evolution of microstructure...
In the transition to lead-free process, one of the most prominent problems is the lead-free solder joint interconnection reliability. Interconnection failure analysis is an important tool for improving the lead-free PCBA product design as well as assembly process quality. Combining a typical fault case, this study deeply analyzed the failure phenomena and the failure mechanism as to interconnection...
Electronic components continue to high reliability, high performance, multi-functional, miniaturization direction. High-density integrated ball grid array (BGA) surface assembly technology is widely used in the field of microelectronics packaging. In this paper, the crack failure behavior of plastic ball grid array (PBGA) is studied under mechanical vibration load. The stress - strain distribution...
Synchrotron radiation x-ray real-time imaging technology was used to study the interface reactions of Sn/Cu and Sn0.7Cu/Cu joints during reflow with soldering time of 1h under temperature of 300/350 °C. This experiment allows us in-situ observe the interfacial IMCs growth and completely avoids Cu6Sn5 precipitation from the solder in cooling stage to affect the morphology and thickness of interfacial...
With the requirements of higher board level reliability, researchers gradually turned attention to complex composition solders like Sn-Ag-Cu-Ni-Bi solders. This quinary system solder has lower melting point and higher tensile strength than traditional Sn-Ag-Cu solder, which may good for the reliability. In this research, the effects of tensile strength on thermal fatigue properties of Sn-2Ag-0.5Cu-0...
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