Papers about halogen-free
by Gordon Clark, Renee Michalkiewicz, Timothy Jensen , Brian Toleno, Jasbir Bath
Over the last few years, there has been an increase in the evaluation and use of halogen-free soldering materials. In addition, there has been increased scrutiny into the level of halogens and refinement of the definition and testing of halogen-free soldering materials. The challenge has been that there has been no common standard across the industry in terms of halogen-free definitions and the corresponding test methods to determine these. This has created confusion in the industry as to what end users want and what soldering materials suppliers can actually provide. This paper will review the status of both halogen-free and halide-free in terms of definitions, test methods and the limitations and accuracy of test methods used to determine if a soldering material is halogen/halide-free or not. For halogen-free and halide-free definitions, the paper will review the different industry standards which are currently available and those being drafted, and it will discuss any similarities and differences. It will also cover the origins of some of the definitions mentioned in the standards. The paper will include a review of the accuracy and limitations of several test methods and preparation techniques for halogen and halide determination.
Apex 2011, soldering materials, halides, halogen-free
[Permanent Link to this Paper ]
Posted on 11 Apr 2011
by Mario Scalzo
Chinese version of Addressing the Challenge of Head-in-Pillow Defects in Electronics Assembly.
CHINESE LANGUAGE, halogen-free, head-in-pillow, pb-free, solder defects, solder paste, solder reliability, lead-free
[Permanent Link to this Paper ]
Posted on 11 Mar 2010
by Mario Scalzo
White Paper Video
Addressing the Challenge of Head-in-Pillow Defects in Electronics Assembly
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The head-in-pillow defect has become a relatively common failure mode in the industry since the implementation of
Pb-free technologies, generating much concern. A head-in-pillow defect is the incomplete wetting of the entire solder joint of a ball-grid array (BGA), chip-scale package (CSP), or even a package- on-package (PoP), and is characterized as a process anomaly, where the solder paste and BGA ball both reflow but do not coalesce. When looking at a cross- section, it actually looks like a head has pressed into a soft pillow. There are two main sources of head-in-pillow defects: poor wetting and printed writing board (PWB) or package warpage. Poor wetting can result from a variety of sources, such as solder ball oxidation, an inappropriate thermal reflow profile or poor fluxing action. This paper addresses the three sources or contributing issues (supply, process and material) of the head-in-pillow defects. It will thoroughly review these three issues and how they relate to result in head-in-pillow defects. In addition, a head-in-pillow elimination plan will be presented with real life examples to illustrate these solutions.
lead-free, solder reliability, solder paste, solder defects, pb-free, head-in-pillow, halogen-free
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Posted on 11 May 2009
by Dr. Ronald C. Lasky
Miniaturised electronics and the advent of
lead-free soldering have added new challenges to the SMT electronic assembly process, most notably in the arenas of stencil printing and reflow. Recent work on improving these assembly processes and advances in solder paste technology can help to minimise these process challenges.
halogen-free, solder paste, solder, solder reliability, flux, pb-free, lead-free
[Permanent Link to this Paper ]
Posted on 15 Mar 2009
by Timothy Jensen , Dr. Ronald C. Lasky
Chinese version of Challenges of Implementing a
Halogen-Free PCB Assembly Process.
oxidation barrier, activator, pb-free, reflow, graping, head-in-pillow, halide-free, halogen-free, halogens, CHINESE LANGUAGE
[Permanent Link to this Paper ]
Posted on 22 Mar 2010
by Dr. Ronald C. Lasky , Timothy Jensen
The electronics industry continues to strive to provide more environmentally friendly products. This movement is partly due to legislation from various countries, partly due to public outcry from well publicized 3rd world recycling practices, and partly due to non-government organizations (NGOs) testing and publishing information on electronic devices regarding their content of various toxic materials. One set of materials targeted for reduction and eventual elimination are halogenated compounds. Halogens are found in plastics for cables and housings, board laminate materials, components, and soldering fluxes. Replacing these halogenated compounds can have a dramatic affect on the PCB
assembly process. In this paper those challenges will be discussed as well as techniques and practices that will help ensure high end of line yields and continued reliability.
oxidation barrier, activator, pb-free, reflow, graping, head-in-pillow, halide-free, halogen-free, halogens
[Permanent Link to this Paper ]
Posted on 4 Mar 2010
by Timothy Jensen , Dr. Ronald C. Lasky
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Challenges for Implementing a Halogen-Free Process
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The drive to produce halogen-free electronics has grown significantly, driven partly by legislation and partly by environmentalist organizations. This paper will discuss the challenges of implementing such a halogen-free assembly process. It will start by briefly discussing the reasons that “halogen-free” is with us. The PCB materials that might contain halogens will then be presented. PWB and component concerns will be briefly reviewed. The bulk of the paper will center on the process development issues in establishing a halogen-free assembly process, including solder paste evaluation and selection, solder fluxes, the SMT stencil printing process, reflow and test. Comparisons between halogen containing and halogen-free solder pastes regarding their process performance and reliability will also be presented. The paper will close with a brief review of techniques to analyze halogen content in materials and some of the pitfalls if inappropriate tests are used.
halogen-free
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Posted on 11 May 2009
by Chris Anglin
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Establishing a Precision Stencil Printing Process for Miniaturized Electronics Assembly
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The advent of miniaturized electronics for mobile phones and other portable devices has required the assembly of smaller and smaller components. Currently 01005 passives and 0.3mm CSPs are some of the components that must be assembled to enable these portable electronic devices. It is widely accepted that about 65% of all end of the line defects occur in the stencil printing process. Given all of the above it is critical that a precision stencil printing process be developed to support miniaturized electronic assembly.
This paper will be a summary of a significant amount of experimental data and process optimization techniques that were employed to establish precision SMT printing process. Our results indicate that the industry standard stencil aperture aspect ratio requirement of > 0.66 is an excellent rule of thumb. However, by optimizing printer setup with vacuum support, foil-less clamps, squeegee edge guards etc and assuring cleanliness and squeegee and stencil quality, we have been able to obtain acceptable stencil printing results with area ratios of 0.5 with Type III solder pastes. The work that was performed to achieve these results will be discussed in detail in the paper.
halogen-free, solder paste, solder, solder reliability, flux, solder quality, stencil printing
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Posted on 11 May 2009
by Paul Socha
Solder fabrications, generally referred to as
preforms , can be made to fit many different and unique applications. Preforms are designed to have a particular shape and deliver a specified volume of solder to the solder joint. Preforms can be divided into two subclasses: conventional, where the preforms are punched from solder ribbon, and InTEGRATED® preforms, which are chemically etched from solder foil. In this article, we will discuss how InTEGRATED® preforms are used and, in particular, methods that are frequently utilized to reflow them to maximize quality and production.
halogen-free solder paste, halogen-free, head, pillow, head in pillow defect, integrated preforms
[Permanent Link to this Paper ]
Posted on 8 Mar 2010
by ICA
A Contract Equipment Manufacturer conducted an
independent “live”production line test of two solder
pastes and confirmed the age-old adage “You get what
you pay for.”Today’s electronics industry derives its
strength from global marketplace competitive pricing
but beyond price is the overall impact of quality and
production achieved by using technologically superior
products — even if they cost a little more.Solder paste,
an often-undervalued component necessary for elec-
tronics manufacturing,generated significant savings by
achieving higher yields, reducing solder paste scrap,
and eliminating nitrogen processing costs.
halogen-free solder paste, halide-free solder paste, halogen-free, halide-free, head, pillow, head-in-pillow, head in pillow defect, NC-SMQ92J
[Permanent Link to this Paper ]
Posted on 8 Mar 2010
by Dr. Ning-Cheng Lee , Dr. Arnab Dasgupta, Dr. Runsheng Mao, Dr. Yan Liu
Electronic industry has been driven toward lead-free by RoHS (Restriction of Hazardous Substances Directive) which is in force since 2006. Recently REACH (Registration, Evaluation and Authorization of Chemicals) further drives the industry toward halogen-free. As a result, solder pastes for PCB assembly are required or desired to be both lead-free and halogen-free. Lead-free solder alloys in general wet poorer than tin-lead due to the higher surface tension of the former alloys. In the mean time, halogen-free fluxes typically also wet poorer than the more powerful halogen-containing fluxes. Consequently, the lead-free and halogen-free solder paste products that emerged inevitably suffer from a considerably inferior soldering performance than that of conventional halogen-containing tin-lead solder pastes. The deficiencies include poor wetting, solder balling, voiding, graping, head-in-pillow, etc. This gap is particularly significant for fine-pitch applications where the impact of oxidation is more profound. Furthermore, the higher soldering temperature of the higher melting lead-free alloys also aggravates the challenge of in-circuit test for no- clean processes, mainly due to the difficulty for probe to penetrate through the toughened flux residue. Although use of inert reflow atmosphere may alleviate some of the problems, the higher cost of it is prohibitive for most of the manufacturing firms. In this work, a halogen-free lead-free no-clean solder paste system, Indium8.9HF series, has been developed. It exhibits superior oxidation tolerance, thus assures superior resistance against graping, head-in-pillow, solder balling, voiding, and poor wetting for miniaturized electronic applications. In spite of the immense challenge in material science, this system also shows outstanding probe testability, in addition to its very good printability, non- slump, SIR, and ECM performance. The superior performance of this Indium8.9HF system effectively sealed the gap caused by lead-free and halogen-free requirements.
lead-free, halogen-free, no-clean, solder, solder paste, miniaturization, graping, head-in-pillow, voiding, solder balling, probe testability, ICT, oxidation
[Permanent Link to this Paper ]
Posted on 1 Jan 2009
by Amanda Hartnett , Dr. Ronald C. Lasky , Timothy Jensen
Chinese version of Soldering Challenges in a Halogen-Free PCB Assembly Process
halogen-free, halide-free, solder, soldering, graping, flux, head-in-pillow, hole-fill, CHINESE LANGUAGE
[Permanent Link to this Paper ]
Posted on 13 May 2011
by Timothy Jensen , Dr. Ronald C. Lasky , Amanda Hartnett
Flame retardants have played an important role in the safety of many products. It is safe to say that thousands of lives have been saved by flame retardants. Flame retardants are used in products as varied as children's pajamas to electronics assemblies. Some of the more successful flame retardants are halogenated compounds. Halogenated materials are found in polyvinyl chloride (PVC), brominated flame retardants (BFRs), chlorinated flame retardants (CFRs), as well as in fluxes used in the electronics assembly industry. Product does not contain any halogenated compounds. However, that is not exactly how the term is used for soldering fluxes. A flux that is classified as
halide-free by the IPC/J-STD-004 is actually only free of ionic halides.
hole-fill, head-in-pillow, flux, graping, soldering, solder, halide-free, halogen-free
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Posted on 10 Mar 2010
by Eric Bastow
With the predominance of no-clean soldering processes and ever decreasing component standoff, the industry has had to consider the reliability of, what may be, partially activated or "gooey" flux residues under component bodies. Similarly, questions have also risen about the reliability of flux residues resulting from the reflow of no-clean solder pastes that are "entrapped" under RF shields or "cans", where escape of the volatile ingredients of the flux is greatly hindered. In this paper, discussion will be made regarding an experiment designed to mimic the aforementioned conditions and how these conditions affected the SIR performance of the no-clean flux residues. A variety of no-clean solder paste flux residues will be discussed, including a halogen-containing, Pb-free solder paste flux; a halogen-free, Pb-free solder paste flux; a halogen-free, Pb-free solder paste flux with a residue optimized for pin probing; and a halogen-free SnPb solder paste flux.
Apex 2011, solder paste, pb-free, halogen-free, no-clean flux, flux residue
[Permanent Link to this Paper ]
Posted on 11 Apr 2011
