Solder Selection of Lead-Free Reflow Soldering and Optimization of Craft Curve

2011 ◽  
Vol 323 ◽  
pp. 70-74
Author(s):  
Wan Gang Wang ◽  
Yong Peng
Keyword(s):  
Great Reduction ◽  
Temperature Curve ◽  
Lead Free ◽  
Lead Free Solder ◽  
Surface Mount Technology ◽  
Reflow Soldering ◽  
Free Process ◽  
Free Solder ◽  
The Stability ◽  
Selection Of

Lead-free reflow soldering craft is the most important solder craft in surface mount technology at present. However, the great reduction of crafting window brings challenges to the soldering quality and also poses higher requirement for the stability and reliability of lead-free soldering equipment. This article analyzes problems out of lead-free process, introduces the selecting principle of lead-free solder and analyzes the optimizing gist of temperature curve of lead-free reflow soldering.

Thermo-mechanical challenges of reflowed lead-free solder joints in surface mount components: a review

2016 ◽  
Vol 28 (2) ◽  
pp. 41-62 ◽  
Author(s):  
Chun Sean Lau ◽  
C.Y. Khor ◽  
D. Soares ◽  
J.C. Teixeira ◽  
M.Z. Abdullah
Keyword(s):  
Solder Joints ◽  
Simulation Modelling ◽  
Lead Free ◽  
Lead Free Solder ◽  
Reflow Process ◽  
Reflow Soldering ◽  
Content Type ◽  
Surface Mount ◽  
Soldering Process ◽  
Free Solder

Purpose The purpose of the present study was to review the thermo-mechanical challenges of reflowed lead-free solder joints in surface mount components (SMCs). The topics of the review include challenges in modelling of the reflow soldering process, optimization and the future challenges in the reflow soldering process. Besides, the numerical approach of lead-free solder reliability is also discussed. Design/methodology/approach Lead-free reflow soldering is one of the most significant processes in the development of surface mount technology, especially toward the miniaturization of the advanced SMCs package. The challenges lead to more complex thermal responses when the PCB assembly passes through the reflow oven. The virtual modelling tools facilitate the modelling and simulation of the lead-free reflow process, which provide more data and clear visualization on the particular process. Findings With the growing trend of computer power and software capability, the multidisciplinary simulation, such as the temperature and thermal stress of lead-free SMCs, under the influenced of a specific process atmosphere can be provided. A simulation modelling technique for the thermal response and flow field prediction of a reflow process is cost-effective and has greatly helped the engineer to eliminate guesswork. Besides, simulated-based optimization methods of the reflow process have gained popularity because of them being economical and have reduced time-consumption, and these provide more information compared to the experimental hardware. The advantages and disadvantages of the simulation modelling in the reflow soldering process are also briefly discussed. Practical implications This literature review provides the engineers and researchers with a profound understanding of the thermo-mechanical challenges of reflowed lead-free solder joints in SMCs and the challenges of simulation modelling in the reflow process. Originality/value The unique challenges in solder joint reliability, and direction of future research in reflow process were identified to clarify the solutions to solve lead-free reliability issues in the electronics manufacturing industry.

Research on Creep Properties of Sn2.5Ag0.7CuXRE Lead-Free Soldered Joints for Surface Mount Technology

2007 ◽  
Vol 353-358 ◽  
pp. 2912-2915 ◽  
Author(s):  
Ke Ke Zhang ◽  
Yao Li Wang ◽  
Yan Li Fan ◽  
Jie Yiang ◽  
Yan Fu Yan ◽  
...  
Keyword(s):  
Rupture Life ◽  
Creep Property ◽  
Creep Rupture ◽  
Lead Free ◽  
Lead Free Solder ◽  
Surface Mount Technology ◽  
Cross Sectional ◽  
Creep Properties ◽  
Surface Mount ◽  
Free Solder

Creep property of solder alloys is one of the important factors to effect the reliability of surface mount technology (SMT) soldered joints. The creep behavior and its rupture life of Sn2.5Ag0.7CuXRE lead-free soldered joints were separately investigated and predicted under constant temperature by a single shear lap creep specimen with a 1mm2 cross sectional area and finite element method (FEM) in this paper. Results show that the creep property of Sn2.5Ag0.7Cu0.1RE is superior to that of the commercial employed lead-free solder Sn3.8Ag0.7Cu and the creep rupture life of its soldered joints is 8.4 times more than that of Sn2.5Ag0.7Cu solder. The creep rupture life of Sn2.5Ag0.7CuXRE lead-free soldered joints indirectly predicted by FEM is better in accord with that of actual testing results, which are important to design the reliability of lead-free soldered joints for SMT.

An Investigation of the Lead-Free Surface Mount Soldering Process: Solder Joint Evaluation and Process Optimisation

2004 ◽  
Author(s):  
Claire Ryan ◽  
Jeff M. Punch ◽  
Bryan Rodgers ◽  
Greg Heaslip ◽  
Shane O’Neill ◽  
...  
Keyword(s):  
Screen Printing ◽  
Solder Joints ◽  
Lead Free ◽  
Lead Free Solder ◽  
Solder Paste ◽  
Surface Mount ◽  
Snagcu Solder ◽  
Soldering Process ◽  
Free Process ◽  
Free Solder

A European Union ban on lead in most electrical and electronic equipment will be imposed as of July 1st 2006. The ban, along with market pressures, means that manufacturers must transfer from a tin-lead soldering process to a lead-free process. In this paper the implications on the surface mount (SMT) soldering process are presented. A set of experiments was conducted to investigate the screen-printing and reflow steps of the SMT process using a tin-silver-copper (95.5Sn3.8Ag0.7Cu) solder and a baseline of standard tin-lead (63Sn37Pb). 10×10 arrays of micro Ball Grid Array (micro-BGA) components mounted on 8-layer FR4 printed wiring boards (PWBs) were used. The screen-printing experiment addressed the deposition of the solder paste on the board. The parameters used in the investigation were print speed, squeegee pressure, snap-off distance, separation speed and cleaning interval, with the responses being measurements of paste height and volume. Optimum screen-printer settings were determined which give adequate paste volume and height and a good print definition. The reflow experiment investigated the following parameters of the temperature profile: preheat, soak, peak and cool down temperatures, and conveyor speed. The resulting solder joints were evaluated using cross-section analysis and x-ray techniques in order to determine the presence of defects. A mechanical fatigue test was also carried out in order to compare the strength of the solder joints. The overall quality of the lead-free solder joints was determined from these tests and compared to that of tin-lead. The outcome is a set of manufacturing guidelines for transferring to lead-free solder including optimum screen-printer and reflow oven settings for use with an SnAgCu solder.

Effect of Nickel Doping on Interfacial Reaction between Lead-Free Solder and Ni-P Substrate

2012 ◽  
Vol 488-489 ◽  
pp. 1375-1379 ◽  
Author(s):  
O. Saliza Azlina ◽  
A. Ourdjini ◽  
I. Siti Rabiatull Aisha
Keyword(s):  
Isothermal Aging ◽  
Environmental Concern ◽  
Aging Treatment ◽  
Electroless Nickel ◽  
Lead Free ◽  
Lead Free Solder ◽  
Reflow Soldering ◽  
Nickel Doping ◽  
Free Solder ◽  
Sac Solder

Due to environmental concern, lead-free solder are taking the place of eutectic Sn-Pb solder in electronic packaging industry. Among various lead free alloys, Sn–Ag–Cu (SAC) alloys are leading lead-free candidate solders for various applications because it is offered better properties. This study investigates the interfacial reactions during reflow soldering and isothermal aging between Sn-3.0Ag-0.5Cu (SAC305) and Sn-3.0Ag-0.5Cu-0.05Ni (SACN30505) on electroless nickel/ immersion palladium/immersion gold (ENEPIG) surface finish. The substrates were subjected to isothermal aging at 125°C for up to 2000 hours with solder size diameter of 500μm. The results indicated that after reflow soldering, (Cu, Ni)6Sn5 IMC is formed between solder and substrate while after aging treatment a new IMC was formed between (Cu, Ni)6Sn5 and substrate known as (Ni, Cu)3Sn4. Moreover, after soldering and isothermal aging, Ni-doped (SACN) solder represents a thicker IMC compared to SAC solder. Aging time of solder joints results in an increase of IMC’s thickness and changes their morphologies to become more spherical, dense and with larger grain size. In addition, the results also revealed that the thickness of intermetallics formed is proportional to the aging duration.

Effect of Different Aging Temperatures on Interfacial Reaction between SAC305 and ENEPIG Surface Finish

2011 ◽  
Vol 415-417 ◽  
pp. 1181-1185 ◽  
Author(s):  
Osman Saliza Azlina ◽  
Ali Ourdjini ◽  
Siti Rabiatull Aisha Idris ◽  
Mohd Ariff Azmah Hanim
Keyword(s):  
Isothermal Aging ◽  
Aging Treatment ◽  
Electroless Nickel ◽  
Lead Free ◽  
Green Product ◽  
Hazardous Substance ◽  
Lead Free Solder ◽  
Reflow Soldering ◽  
Packaging Industry ◽  
Free Solder

In electronic packaging industry, they are now driven technology to green product by replacing leaded-solder with lead-free solder in order to fulfill the European Restriction of Hazardous Substance (RoHS) compliance. Thus, Sn-Ag-Cu lead-free solder family is one of candidates can fulfill this requirement. This study investigates the interfacial reactions during reflow soldering and isothermal aging between Sn-3.0Ag-0.5Cu (SAC305) and electroless nickel/ immersion palladium/immersion gold (ENEPIG). Reliability of solder joint is also examined by performing solid state isothermal aging at 125°C and 150°C for up to 2000 hours. The results revealed that after reflow soldering, (Cu, Ni)6Sn5 IMC is formed between solder and substrate while after aging treatment another IMC was found between (Cu, Ni)6Sn5 and substrate known as (Ni, Cu)3Sn4. Aging time and temperature of solder joints results in an increase of IMC’s thickness and changes their morphologies to become more spherical, dense and with larger grain size. In addition, the results also revealed that the thickness of intermetallics formed is proportional to the aging duration and temperature.

scholarly journals Study on the Addition of Nanoparticles in the Lead-free Solder During Reflow Soldering via Numerical Simulation - A Review

CFD letters ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 111-119
Author(s):  
Intan Norshalina Sahrudin ◽  
Mohd Sharizal Abdul Aziz ◽  
Mohd. Zulkifly Abdullah ◽  
Mohd Arif Anuar Mohd Salleh
Keyword(s):  
Numerical Simulation ◽  
Lead Free ◽  
Lead Free Solder ◽  
Reflow Soldering ◽  
Free Solder
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