Numerical and experimental study on laser soldering process of SnAgCu lead-free solder

2021 ◽  
pp. 125046
Author(s):  
Zifan Yang ◽  
Lijing Li ◽  
Wen Chen ◽  
Xudong Jiang ◽  
Yueli Liu
Keyword(s):  
Experimental Study ◽  
Lead Free ◽  
Lead Free Solder ◽  
Soldering Process ◽  
Laser Soldering ◽  
Free Solder

Development of high speed laser soldering process for lead-free solder with diode-laser

2003 ◽  
Author(s):  
Jing-bo Wang ◽  
Mamoru Watanabe ◽  
Yasuhiro Goto ◽  
Kouji Fujii ◽  
Hiroyuki Kuriaki ◽  
...  
Keyword(s):  
Diode Laser ◽  
High Speed ◽  
Lead Free ◽  
Lead Free Solder ◽  
Soldering Process ◽  
Laser Soldering ◽  
Free Solder

Influence of Laser Soldering Temperatures On Thru-Hole Component

2021 ◽  
Author(s):  
Saiful Majdy ◽  
Mohamad Aizat Abas ◽  
Mohamad Fikri Mohd Sharif ◽  
Fakhrozi Che Ani
Keyword(s):  
High Pressure ◽  
Three Dimensional ◽  
Void Formation ◽  
Lead Free ◽  
Bottom Surface ◽  
Lead Free Solder ◽  
Soldering Process ◽  
Incomplete Filling ◽  
Laser Soldering ◽  
Free Solder

Abstract The conventional method of selective soldering has been practiced using wave soldering, convection reflow, and hand soldering. However, due to industry automation and high demand for quality, repeatability and flexibility, laser soldering process has been developed to meet these demands. This paper investigates the effect of different temperature of laser soldering process on lead free solder (SAC305) by means of numerical method that is validated by experiment. Finite Volume Method (FVM) was used for the three-dimensional (3D) simulation to simulate the filling flow of the lead-free solder. Experiments were carried out to complement simulation validity and the results of far both methods have reached a good agreement. The findings show that a better result can be achieved when angle of lead component (?le) approaches 90°. Using the optimized lead angle, five different temperature simulations were set in the range of 550K < T < 700K. The finding shows that, 600K has the best velocity and pressure distributions with average values of 63.3 mm/s and 101.1386kPa, respectively. The high-pressure region is concentrated at the top and bottom surface of solder pad. High difference in pressure and velocity spots somehow lead to issue associated with possibility of incomplete filling or void formation. 650K model shows less void formation since it produces high pressure filling flow within the solder region.

A Comparative Study of Soldering Temperatures and Materials on the Reliability of Photovoltaic Modules

2012 ◽  
Vol 562-564 ◽  
pp. 188-191
Author(s):  
Keh Moh Lin ◽  
Yang Hsien Lee ◽  
Wen Yeong Huang ◽  
Po Chun Hsu ◽  
Chin Yang Huang ◽  
...  
Keyword(s):  
Comparative Study ◽  
Lead Free ◽  
Automatic Process ◽  
Lead Free Solder ◽  
Snagcu Solder ◽  
Photovoltaic Modules ◽  
Soldering Process ◽  
Different Temperatures ◽  
Free Solder

To find out the important factors which decisively affect the soldering quality of photovoltaic modules, solar cells were soldered under different conditions (different temperatures, PbSn vs. SnAgCu solder, manual vs. semi-automatic). Experimental results show that the soldering quality of PbSn under 350°C in the semi-automatic soldering process was quite stable while the soldering quality of lead-free solder was generally unacceptable in the manual or semi-automatic process under different temperatures. This result indicates that the soldering process with lead-free solder still needs to be further improved. It was also found that most cracks were formed on the interface between the solder and the silver paste and then expanded outwards.

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.

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.

Experimental Study of Void Formation in Eutectic and Lead-Free Solder Bumps of Flip-Chip Assemblies

2005 ◽  
Vol 128 (3) ◽  
pp. 202-207 ◽  
Author(s):  
Daijiao Wang ◽  
Ronald L. Panton
Keyword(s):  
Experimental Study ◽  
Heat Flux ◽  
Flip Chip ◽  
Void Formation ◽  
Lead Free ◽  
Void Volume ◽  
Lead Free Solder ◽  
Solder Bumps ◽  
Free Solder ◽  
High Lead

This paper reports the experimental findings of void formation in eutectic and lead-free solder joints of flip-chip assemblies. A previous theory indicated that the formation of voids is determined by the direction of heating. The experiments were designed to examine the size and location of voids in the solder samples subject to different heat flux directions. A lead-free solder (Sn-3.5Ag-0.75Cu) and a eutectic solder (63Sn37Pb) were employed in the experiments. Previous experiments [Wang, D., and Panton, R. L., 2005, “Experimental Study of Void Formation in High-Lead Solder Joints of Flip-Chip Assemblies,” ASME J. Electron. Packag., 127(2), pp. 120–126; 2005, “Effect of Reversing Heat Flux Direction During Reflow on Void Formation in High-Lead Solder Bumps,” ASME J. Electron. Packag., 127(4), pp. 440–445] employed a high lead solder. 288 solder bumps were processed for each solder. Both eutectic and lead-free solder have shown fewer voids and much smaller void volume than those for high-lead solder. Compared with lead-free solder, eutectic solder has a slightly lower void volume and a lower percentage of defective bumps. For both eutectic and lead-free solders, irrespective of the cooling direction, heating solder samples from the top shows fewer defective bumps and smaller void volume. No significant effect on void formation for either eutectic or lead-free solder was found via reversing the heat flux direction during cooling. Unlike high-lead solder, small voids in eutectic or lead-free solder comprised 35-88% of the total void volume. The final distribution of voids shows a moderate agreement with thermocapillary theory, indicating the significance of the temperature gradient on the formation of voids.

Laser soldering of Sn-Ag-Cu and Sn-Zn-Bi lead-free solder pastes

2004 ◽  
Author(s):  
Junichi Takahashi ◽  
Sumio Nakahara ◽  
Shigeyoshi Hisada ◽  
Takeyoshi Fujita
Keyword(s):  
Lead Free ◽  
Lead Free Solder ◽  
Laser Soldering ◽  
Solder Pastes ◽  
Free Solder

Influence of the fluxes properties on quality and the microstructure of lead-free solder joints executed by selective soldering

2014 ◽  
Vol 26 (1) ◽  
pp. 2-7 ◽  
Author(s):  
Marek Koscielski ◽  
Janusz Sitek
Keyword(s):  
Cross Sections ◽  
Solder Joints ◽  
Lead Free ◽  
Lead Free Solder ◽  
Dynamic Activity ◽  
Content Type ◽  
Soldering Process ◽  
Different Types ◽  
Free Solder ◽  
Solids Content

Purpose – The purpose of this paper is to investigate the influence of the properties of new compositions of fluxes for selective soldering on lead-free solder joints quality and microstructures as well as showing which flux properties are the most important. Design/methodology/approach – The three different types of fluxes were tested, which differed in composition, solids content, amount and type of activators added. The selective soldering process was done with the use of lead-free solder SAC 305. The test boards had two coatings SnCu (HASL) or Au/Ni. Basic chemical and physical properties of fluxes were examined according to the relevant standards. Different types of components from the bulky ones, demanding more heat, to the smaller ones were used during the assembly process. AOI and X-ray analyses as well as cross-sections and SEM analyses were utilized to deeply assess the quality and microstructure of the investigated solder joints. Findings – The results showed that information about density or static activity of flux is not enough for correct flux assessment. The dynamic activity of flux measured by wetting balance method is the best for this, especially in the case when there is short soldering time and heat transfer is hindered. The quality and the microstructure of lead-free solder joints are related not only with wetting properties of the flux used for soldering but also with other properties like solids content in a flux. Research limitations/implications – It is suggested that further studies are necessary for the confirmation of the practical application, especially of the reliability properties of the joints obtained with the use of the elaborated fluxes. Originality/value – The results showed that type of flux (ORL or ROL) as well as minor changes in their dynamic activity and solids content might have significant influence on quality of solder joints and their microstructure. It was noted that selective soldering is demanding technique and optimization of soldering process for different type of components and fluxes is important.

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