Influence of Laser Soldering Temperatures On Thru-Hole Component

Author(s):  
Saiful Majdy ◽  
Mohamad Aizat Abas ◽  
Mohamad Fikri Mohd Sharif ◽  
Fakhrozi Che Ani

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.

2003 ◽  
Author(s):  
Jing-bo Wang ◽  
Mamoru Watanabe ◽  
Yasuhiro Goto ◽  
Kouji Fujii ◽  
Hiroyuki Kuriaki ◽  
...  

2012 ◽  
Vol 562-564 ◽  
pp. 188-191
Author(s):  
Keh Moh Lin ◽  
Yang Hsien Lee ◽  
Wen Yeong Huang ◽  
Po Chun Hsu ◽  
Chin Yang Huang ◽  
...  

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.


2017 ◽  
Vol 66 (4) ◽  
pp. 1229-1237 ◽  
Author(s):  
P. Wild ◽  
T. Grozinger ◽  
D. Lorenz ◽  
A. Zimmermann

2015 ◽  
Vol 772 ◽  
pp. 284-289 ◽  
Author(s):  
Sabuj Mallik ◽  
Jude Njoku ◽  
Gabriel Takyi

Voiding in solder joints poses a serious reliability concern for electronic products. The aim of this research was to quantify the void formation in lead-free solder joints through X-ray inspections. Experiments were designed to investigate how void formation is affected by solder bump size and shape, differences in reflow time and temperature, and differences in solder paste formulation. Four different lead-free solder paste samples were used to produce solder bumps on a number of test boards, using surface mount reflow soldering process. Using an advanced X-ray inspection system void percentages were measured for three different size and shape solder bumps. Results indicate that the voiding in solder joint is strongly influenced by solder bump size and shape, with voids found to have increased when bump size decreased. A longer soaking period during reflow stage has negatively affectedsolder voids. Voiding was also accelerated with smaller solder particles in solder paste.


Author(s):  
Muhammad Naqib Nashrudin ◽  
Mohamad Aizat Abas ◽  
Mohd Z. Abdullah ◽  
M. Yusuf Tura Ali ◽  
Zambri Samsudin

Abstract The conventional capillary underfill process has been a common practice in the industry, somehow the process is costly and time consuming. Thus, no-flow underfill process is developed to increase the effective lead time production since it integrates the simultaneous reflow and cure of the solder interconnect and underfill. This paper investigates the effect of different dispense patterns of no-flow underfill process by mean of numerical and experimental method. Finite volume method (FVM) was used for the three-dimensional simulation to simulate the compression flow of the no-flow underfill. Experiments were carried out to complement the simulation validity and the results from both studies have reached a good agreement. The findings show that of all three types of dispense patterns, the combined shape dispense pattern shows better chip filling capability. The dot pattern has the highest velocity and pressure distribution with values of 0.0172 m/s and 813 Pa, respectively. The high-pressure region is concentrated at the center of the chip and decreases out towards the edge. Low in pressure and velocity flow factor somehow lead to issue associated to possibility of incomplete filling or void formation. Dot dispense pattern shows less void formation since it produces high pressure underfill flow within the BGA. This paper provides reliable insight to the industry to choose the best dispense pattern of recently favorable no-flow underfill process.


2016 ◽  
Vol 28 (2) ◽  
pp. 41-62 ◽  
Author(s):  
Chun Sean Lau ◽  
C.Y. Khor ◽  
D. Soares ◽  
J.C. Teixeira ◽  
M.Z. Abdullah

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.


Author(s):  
Claire Ryan ◽  
Jeff M. Punch ◽  
Bryan Rodgers ◽  
Greg Heaslip ◽  
Shane O’Neill ◽  
...  

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.


2007 ◽  
Vol 22 (4) ◽  
pp. 826-830 ◽  
Author(s):  
J.W. Jang ◽  
J.K. Lin ◽  
D.R. Frear ◽  
T.Y. Lee ◽  
K.N. Tu

Void formation in lead-free solder joints, away from the joint interface, has been observed after solid-state aging. These voids are attached to intermetallic precipitates in the solder matrix, especially to those that are adjacent to the layered intermetallic at the joint interface. Two potential void formation mechanisms are discussed. The mechanism proposed to describe void formation is that a flux of vacancies is created due to volume contraction during solid-state reaction. The ripening process among the intermetallics also assists this process. Using the suggested mechanisms, the void size was estimated. This phenomenon differs from the classical Kirkendall void formation because it is a nonequilibrium state of void formation and stress generation.


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