Electrochemical migration behaviour of surface finishes after vapour phase reflow soldering

2014 ◽  
Author(s):  
Balazs Illes ◽  
Balint Medgyes ◽  
Andars Horvath
Keyword(s):  
Vapour Phase ◽  
Electrochemical Migration ◽  
Reflow Soldering ◽  
Migration Behaviour ◽  
Surface Finishes

PCB Related Field Failures with ImAg Surface Finishes

2007 ◽  
Author(s):  
Anil Kurella ◽  
Aravind Munukutla ◽  
J.S. Lewis
Keyword(s):  
Emerging Markets ◽  
Galvanic Corrosion ◽  
Electrochemical Migration ◽  
Copper Sulphide ◽  
Electronic Components ◽  
Related Field ◽  
Surface Finishes ◽  
Immersion Silver ◽  
Manufacturing Environments

Abstract PCB surface finishes like Immersion silver (ImAg) are commonly used in Pb-free manufacturing environments following RoHS legislation. With this transition, however the numbers of field failures associated with electrochemical migration, copper sulphide corrosion, via barrel galvanic corrosion are on a steady rise. More often than not ImAg surfaces seem to assist these failing signatures. As computers penetrate into emerging markets with humid and industrialized environments there is a greater concern on the reliability and functionality of these electronic components.

X-ray inspection and Six-Sigma in analysis of LED thermal pad coverage

2017 ◽  
Vol 29 (1) ◽  
pp. 28-33 ◽  
Author(s):  
Barbara Dziurdzia ◽  
Janusz Mikolajek
Keyword(s):  
Six Sigma ◽  
Vapour Phase ◽  
Inspection System ◽  
Solder Paste ◽  
Process Variables ◽  
Reflow Soldering ◽  
Content Type ◽  
X Ray ◽  
Solder Pastes ◽  
Free Solder

Purpose The purpose of this paper is to evaluate selected methods of reduction voidings in lead-free solder joints underneath thermal pads of light-emitting diodes (LEDs), using X-ray inspection and Six Sigma methodology. Design/methodology/approach On the basis of cause and effect diagram for solder voiding, the potential causes of voids and influence of process variables on void formation were found. Three process variables were chosen: the type of reflow soldering, vacuum incorporation and the type of solder paste. Samples of LEDs were mounted with convection and vapour phase reflow soldering. Vacuum was incorporated into vapour phase soldering. Two types of solder pastes OM338PT and LFS-216LT were used. Algorithm incorporated into X-ray inspection system enabled to calculate the statistical distribution of LED thermal pad coverage and to find the process capability index (Cpk) of applied soldering techniques. Findings The evaluation of selected soldering processes of LEDs in respect of their thermal pad coverage and statistical Cpk indices is presented. Vapour-phase soldering with vacuum is capable (Cpk > 1) for OM338PT and LFS-216LT paste. Convection reflow without vacuum with LFS-216LT paste is also capable (Cpk = 1.1). Other technological soldering processes require improvements. Vacuum improves radically the capability of a reflow soldering for an LED assembly. When vacuum is not accessible, some improvement of capability to a lower extent is possible by an application of void-free solder pastes. Originality/value Six Sigma statistical methodology combined with X-ray diagnosis was used to check whether applied methods of void reduction underneath LED thermal pads are capable processes.

Electrochemical migration behaviour of Cu, Sn, Ag and Sn63/Pb37

2011 ◽  
Vol 23 (2) ◽  
pp. 551-556 ◽  
Author(s):  
Bálint Medgyes ◽  
Balázs Illés ◽  
Gábor Harsányi
Keyword(s):  
Electrochemical Migration ◽  
Migration Behaviour

scholarly journals Comparison between SAC405 Lead-Free Solders and EN(P)EPIG and EN(B)EPIG Surface Finishes

2015 ◽  
Vol 773-774 ◽  
pp. 232-236 ◽  
Author(s):  
Osman Saliza Azlina ◽  
Ali Ourdjini ◽  
Mohd Halim Irwan Ibrahim
Keyword(s):  
Isothermal Aging ◽  
Optical Microscope ◽  
Hazardous Substances ◽  
Lead Free ◽  
Grain Size Analysis ◽  
Size Analysis ◽  
Reflow Soldering ◽  
Soldering Process ◽  
Surface Finishes ◽  
Lead Free Solders

In electronics industries, most of them had to shifted their solder materials from leaded solders into lead-free solders due to the environmental concerns and follow the legislation of Restriction of use Hazardous Substances (RoHS). Thus, Sn-Ag-Cu solder is one of the choices that can replace the leaded solder and also offer better properties. This study investigates the comparison between Sn-4.0Ag-0.5Cu (SAC405) and EN(P)EPIG and EN(B)EPIG surface finishes. Reliability of solder joint has been assessed by performing solid state isothermal aging at 150oC for 250 up to 2000 hours. After reflow soldering process, (Cu,Ni)6Sn5intermetallic compound (IMC) is dominated at near centre of solder meanwhile (Ni,Cu)3Sn4IMC is dominated at near outside of solder ball.Moreover, aging time resulted in an increase in thickness and changed the morphology into more spherical, dense and large grain size. Analysis by optical microscope revealed that the IMC thickness of EN(B)EPIG produced thicker IMC compared to EN(P)EPIG surface finish during reflow as well as isothermal aging.

scholarly journals Vapour phase soldering (VPS) technology: a review

2019 ◽  
Vol 31 (3) ◽  
pp. 146-156 ◽  
Author(s):  
Balázs Illés ◽  
Attila Géczy ◽  
Bálint Medgyes ◽  
Gábor Harsányi
Keyword(s):  
Literature Review ◽  
Solder Joints ◽  
Vapour Phase ◽  
Void Content ◽  
Reflow Soldering ◽  
Content Type ◽  
Characterization Methods ◽  
Soldering Process ◽  
Advantages And Disadvantages ◽  
Recent Developments

Purpose This paper aims to present a review of the recent developments in vapour phase soldering (VPS) technology. This study focuses on the following topics: recent developments of the technology, i.e. soft and vacuum VPS; measurement and characterization methods of vapour space, i.e. temperature and pressure; numerical simulation of the VPS soldering process, i.e. condensate layer and solder joint formation; and quality and reliability studies of the solder joints prepared by VPS, i.e. void content and microstructure of the solder joints. Design/methodology/approach This study was written according to the results of a wide literature review about the substantial previous works in the past decade and according to the authors’ own results. Findings Up to now, a part of the electronics industry believes that the reflow soldering with VPS method is a significant alternative of convection and infrared technologies. The summarized results of the field in this study support this idea. Research limitations/implications This literature review provides engineers and researchers with understanding of the limitations and application possibilities of the VPS technology and the current challenges in soldering technology. Originality/value This paper summarizes the most important advantages and disadvantages of VPS technology compared to the other reflow soldering methods, as well as points out the necessary further developments and possible research directions.

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