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.
Considering that solder surface may lose its brightness due to oxidation during the assembly and operation of electronic device, this study investigated the surface properties of Sn-Cu-Ni solders using UV-visible and X-ray photoelectron spectroscopies. The degree of discoloring could be evaluated by the reflectance of the sample surface in the visible light range. Two distinct absorption peaks respectively...
This study aimed to investigate the corrosion resistance in 3.5%NaCl solution and high temperature oxidation behavior of Pb-5Sn solder and its alternatives under development, Bi-11Ag and Zn-40Sn. Compared with Pb-5Sn and Zn-40Sn, Bi-11Ag exhibited higher corrosion potential and relatively low corrosion current density. The ductile Ag-rich phase which dispersed in the Bi matrix was able to accommodate...
In this work, the SAC solder joints with minor Mn or RE (rare earth) additions were bonded on the substrate of OSP Cu surface finishes for evaluating the influence of minor alloying on BIT (ball impact test) behavior. The Mn-doped samples had a better resistance to the degradation in BIT performance suffering long time aging at 150??C. The greater impact force and toughness compared to the other samples...
This study evaluated room temperature creep properties of the intermetallic compounds (IMCs) formed at the interfaces between Pb-free solders (Sn-Ag-Cu and Sn-Zn) and the commonly used electronic substrates (Cu, Ni and Ag) using nanoindentation. The creep stress exponent (CSE), representing creep resistance, in the decreasing order was Cu, Ni and then Ag based IMCs, which was in good agreement with...
This study aimed to investigate the electrochemical corrosion behavior of the potential Pb-free solders, Bi-11 wt%Ag and Zn-40 wt%Sn, in 3.5% NaCl solution using the potentiodynamic polarization method with the scanning range from -2000 mV to +2000 mV. Pb-5 wt%Sn alloy was also examined for comparison. Experimental results show that the corrosion potential (Ecorr) decreased in the decreasing order...
A strain-controllable dynamic bending method on WLCSP has been proposed in this paper. In order to identify the principle factor among the effects of stiffness attributed by different board level structures, the 0.4 mm pitch WLCSP packages with Sn-4.0Ag-0.5Cu solder ball are used. This combination of WLCSP is considered to have the high stiffness in the structure. It is also shown that there are interactions...
This study investigates the effect of alloying additives on the solidification behavior and microstructural characteristics from a metallurgical perspective. Results show that alloying of Mn and Ti resulted in dramatically reduced undercooling coarse eutectic structure and extended volume fraction of proeutectic Sn of which the dendritic size was refined. Those thermal and microstructural changes...
The effect of transition metal (TM) additive of Ni, Co or Zn on the interfacial reactions of the solder joints between Sn-Ag-Cu (SAC) solder and the Cu/Ni(P)/Au substrate was investigated, especially when subsequent to multi-reflowing. (Cu,Ni)6Sn5 formed at the interface of all the joints but the SAC-Ni of which the interfacial compound was (Ni,Cu)6Sn5. The interfacial compounds of the SAC-Co and...
To evaluate the behavior of intermetallic compounds (IMCs) at different loading conditions, this study examined the hardeness and modulus of the IMCs formed at the interfaces between potential Pbfree solders (Sn-Ag-Cu and Sn-Zn) and the substrates of Cu and Ag. Compared to Ag based IMCs, Cu based IMCs are harder, stiffer, but less strain rate sensitive. It is also found that the morphology of the...
In addition to a reduced Ag content, it has been demonstrated that significant improvement of drop test performance of Sn-Ag-Cu solder joints can be achieved by alloying with Mn and Ti. This study aims to investigate the effects of Mn and Ti additives on the microstructure and solidification behavior of Sn-1.0Ag-0.5Cu alloys, as well as mechanical properties and thus to explain how the alloying elements...
In this work, we present ball impact test (BIT) results conducted at an impact velocity of 500 mm/s on Sn-4Ag-0.5Cu, Sn-1Ag-0.5Cu, Sn-1Ag-0.5Cu-0.05Ni, Sn-1.2Ag-0.5Cu-0.05Ni, and Sn-1Ag-0.5Cu- 0.05Ge package-level solder joints, bonded on substrate pads of immersion tin (IT) and direct solder on pad (DSOP) surface finishes. Differences of BIT results with respect to multi-reflow are also reported.
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.