Technical Library | 2011-08-25 17:47:23.0
While SnAgCu (SAC) alloys still dominate Pb-free selection in North America, especially Sn3.0Ag0.5Cu (SAC305), there are alternative material systems available. Any OEM that is concerned about the high reflow temperatures of SAC or relies on ODM, it is im
Technical Library | 2007-03-08 19:31:10.0
Reflow profile has significant impact on solder joint performance because it influences wetting and microstructure of the solder joint. The degree of wetting, the microstructure (in particular the intermetallic layer), and the inherent strength of the solder all factor into the reliability of the solder joint. This paper presents experimental results on the effect of reflow profile on both 63%Sn 37%Pb (SnPb) and 96.5%Sn 3.0%Ag 0.5%Cu (SAC 305) solder joint shear force.
Technical Library | 2022-03-02 21:26:51.0
The solderability of a nickel-palladium-gold (Ni-Pd-Au) finish on a Cu substrate was evaluated for the Pb-free solder, 95.5Sn-3.9Ag-0.6 Cu (wt.%, abbreviated Sn-Ag-Cu) and the eutectic 63Sn-37 Pb (Sn-Pb) alloy. The solder temperature was 245ºC. The flux was a rosin-based mildly activated (RMA) solution. The Ni-Pd-Au finish was tested in the as-fabricated condition as well as after exposure to one of the following accelerated storage (shelf life) regiments: (1) 33.6, 67.2, or 336 hours in the Battelle Class 2 flowing gas environment or (2) 5, 16, or 24 hours of steam aging (88ºC, 90%RH).
Product name: Halogen Free Lead Free Solder Wire Product code: E9650-HF961 Alloy composition: Sn/Ag3.0/Cu0.5 Diameter: 0.2mm, 0.6mm, 0.8mm, 1.0mm, 1.2mm, 1.6mm Packing: 500g/reel, 1kg/reel (10kg/box) Price: Contact us for best price Features:
New Equipment | Solder Materials
AMTECH’s BGA solder spheres are manufactured from virgin materials to meet or exceed the requirements of building or repairing BGA packages. AMTECH BGA solder spheres also exceed both the IPC and MIL standards for purity levels and size tolerances. N
Technical Library | 2021-05-13 16:03:25.0
Sn-based lead-free solders such as Sn-Ag-Cu, Sn-Cu, and Sn-Bi have been used extensively for a long time in the electronic packaging field. Recently, low-temperature Sn-Bi solder alloys attract much attention from industries for flexible printed circuit board (FPCB) applications. Low melting temperatures of Sn-Bi solders avoid warpage wherein printed circuit board and electronic parts deform or deviate from the initial state due to their thermal mismatch during soldering. However, the addition of alloying elements and nanoparticles Sn-Bi solders improves the melting temperature, wettability, microstructure, and mechanical properties. Improving the brittleness of the eutecticSn-58wt%Bi solder alloy by grain refinement of the Bi-phase becomes a hot topic. In this paper, literature studies about melting temperature, microstructure, inter-metallic thickness, and mechanical properties of Sn-Bi solder alloys upon alloying and nanoparticle addition are reviewed
Technical Library | 2022-10-31 17:30:40.0
This paper presents a quantitative analysis of solder joint reliability data for lead-free Sn-Ag-Cu (SAC) and mixed assembly (SnPb + SAC) circuit boards based on an extensive, but non-exhaustive, collection of thermal cycling test results. The assembled database covers life test results under multiple test conditions and for a variety of components: conventional SMT (LCCCs, resistors), Ball Grid Arrays, Chip Scale Packages (CSPs), wafer-level CSPs, and flip-chip assemblies with and without underfill. First-order life correlations are developed for SAC assemblies under thermal cycling conditions. The results of this analysis are put in perspective with the correlation of life test results for SnPb control assemblies. Fatigue life correlations show different slopes for SAC versus SnPb assemblies, suggesting opposite reliability trends under low or high stress conditions. The paper also presents an analysis of the effect of Pb contamination and board finish on lead-free solder joint reliability. Last, test data are presented to compare the life of mixed solder assemblies to that of standard SnPb assemblies for a wide variety of area-array components. The trend analysis compares the life of area-array assemblies with: 1) SAC balls and SAC or SnPb paste; 2) SnPb balls assembled with SAC or SnPb paste.
Technical Library | 2020-10-27 02:07:31.0
For companies that choose to take the Pb-free exemption under the European Union's RoHS Directive and continue to manufacture tin-lead (Sn-Pb) electronic products, there is a growing concern about the lack of Sn-Pb ball grid array (BGA) components. Many companies are compelled to use the Pb-free Sn-Ag-Cu (SAC) BGA components in a Sn-Pb process, for which the assembly process and solder joint reliability have not yet been fully characterized. A careful experimental investigation was undertaken to evaluate the reliability of solder joints of SAC BGA components formed using Sn-Pb solder paste. This evaluation specifically looked at the impact of package size, solder ball volume, printed circuit board (PCB) surface finish, time above liquidus and peak temperature on reliability. Four different BGA package sizes (ranging from 8 to 45 mm2) were selected with ball-to-ball pitch size ranging from 0.5mm to 1.27mm. Two different PCB finishes were used: electroless nickel immersion gold (ENIG) and organic solderability preservative (OSP) on copper. Four different profiles were developed with the maximum peak temperatures of 210oC and 215oC and time above liquidus ranging from 60 to 120 seconds using Sn-Pb paste. One profile was generated for a lead-free control. A total of 60 boards were assembled. Some of the boards were subjected to an as assembled analysis while others were subjected to an accelerated thermal cycling (ATC) test in the temperature range of -40oC to 125oC for a maximum of 3500 cycles in accordance with IPC 9701A standard. Weibull plots were created and failure analysis performed. Analysis of as-assembled solder joints revealed that for a time above liquidus of 120 seconds and below, the degree of mixing between the BGA SAC ball alloy and the Sn-Pb solder paste was less than 100 percent for packages with a ball pitch of 0.8mm or greater. Depending on package size, the peak reflow temperature was observed to have a significant impact on the solder joint microstructural homogeneity. The influence of reflow process parameters on solder joint reliability was clearly manifested in the Weibull plots. This paper provides a discussion of the impact of various profiles' characteristics on the extent of mixing between SAC and Sn-Pb solder alloys and the associated thermal cyclic fatigue performance.
New Equipment | Solder Materials
As the world's leading developer of advanced solder paste materials, Henkel delivers decades of technology and expertise for optimized process performance. With ground breaking new formulations to provide an easy transition to lead-free as well as pr
Industry News | 2002-12-03 15:00:11.0
Practical Components adds new formulations
