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No-Clean Technology
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SMT Process Recommendations Defect Minimization Methods for a No-Clean SMT Process
Paper Abstract Key competitive advantages can be obtained through the minimization of process defects and disruptions. In today's electronic manufacturing processes there are many variables to optimize. By gaining an understanding of what the defects are, and where they come from, is a key step in the process towards defect free/six sigma manufacturing. In the last decade, Surface Mount Technology processes have been slowly converting towards the No-Clean philosophy. This new trend has spawned new processing issues which need to be addressed. This paper will investigate solutions to current problems in the processing of No-Clean SMT processes. These solutions will be critical in the development of successful processes in the electronics industry in the years ahead. 
Why Clean? A saga of 'no-clean' fluxes Protonique Article that tries to answer the question ''Can 'no-clean' fluxes offer reliability in electronics?''. Read it yourself to get an answer.
No-Clean Flux: The Use of Multiple Vendors Can Produce a Reliability Time Bomb AIM Abstract: Incompatibilities between similar solder flux products supplied by different vendors can create serious product reliability problems if not detected during initial product qualification. Due to the multitude of new fluxes being introduced to the industry and the proprietary and varied nature of these formulations, such incompatibilities are certain to arise occasionally. This paper shall explore the dangers manufacturers face when using different no-clean flux chemistries on the same assembly.
Qualification Of No-Clean Materials And Processes For Cleaning Of Printed Circuit Board Assemblies EPA (Environmental Protection Agency) Extensive report (59 pages) about selecting and qualifying no-clean processes, with several case studies.
Considerations for the Pin Probe Testing of No-Clean Paste Residues AIM Pin probe testing difficulties can directly affect products' cost, time to market, and performance. This paper shall address these concerns and discuss the means by which many of the difficulties currently associated with pin probe testing can be eliminated. The most important of these factors are paste chemistry, length of time between reflow and testing, and the type and number of reflow profiles to which the paste is exposed. In addition, testing process variables such as probe point style, probe tube and socket material, spring force, type of contact and material, and the test environment are addressed.
No-Clean Technology Review Pacific Northwest Pollution Prevention Resource Center No-clean approaches can be defined as any approach to a process that allows a previously required cleaning step to be eliminated. When applicable, no-clean strategies are usually the best possible alternative to a current cleaning process. All of the costs and wastes associated with cleaning are completely eliminated. The PPRC’s investigation found that published literature about no-clean approaches focused on one specific application: no-clean applications for soldering in electronics assembly. Two different types of approaches have been used to eliminate the cleaning step required after traditional soldering: using no-clean fluxes and, very recently, using fluxless soldering. This article focusses on no-clean fluxes and will briefly introduce fluxless soldering.
The Development of a Pin Probe Testable Solder Paste AIM Abstract: In theory, all solder pastes are pin probe testable. However, very few pastes possess the broad process window that allows them to perform successfully under a wide-variety of pin testing methods. Furthermore, many solder pastes marketed as ''pin probeable'' leave residues with marginal insulation characteristics that can result in poor long-term reliability. In addition to paste chemistry, the pin probe testability of a solder paste is directly dependent upon several process factors. The most important of these factors are length of time between reflow and testing and the type and number of reflow profiles to which the paste is exposed. Other factors include the type of probes utilized, the spring forces, and the type of parts being probed.
Alternatives to Solvent Cleanable Solderpaste Kester Rather old article of Litton Kester about the various solder paste types in relation to cleaning options after the elimination of CFC-113
No-Clean Soldering to Eliminate CFC-113 and Methyl Chloroform Cleaning of Printed Circuit Board Assemblies EPA (Environmental Protection Agency) This manual, dated 1993, describes some consideration for changing the cleaning process or introducing no-clean. As the title suggest this was written as a guideline to getting rid of CFC-113.
Technical Issues and No-Clean Approaches Pacific Northwest Pollution Prevention Resource Center Webpage about implematation of no-clean technology
Converting RMA Chemistries to No-Clean AIM Abstract: The phaseout of CFC-based solvent cleaning has forced manufacturers of surface mount assemblies to examine alternative cleaning chemistries such as RMA/saponifier, semi-aqueous and water-soluble fluxes with aqueous cleaning. These examinations have led to a growing acceptance of no-clean or low residue fluxes. This paper addresses some of the concerns, explains some unknowns, and offers recommendations to consider when evaluating your position.
Characterization of No Clean Solderpaste Residues: The Relationship to In-Circuit Testing Kester Technical article about probing of testpins through the residues of several types of solderpaste.
A Novel Method For Determining The Pin Testability Of Solder Flux Residue Heraeus Circuit Materials Paper that describes how pin testability can be evaluated as a function of of flux residues and the type of testprobe. (added on 18-Oct-2003)
NO-RESIDUE TECHNOLOGY CHEMISTRY AND PHYSICS Interflux Paper highlighting the importance of interrelating the physics and the chemistry in wave soldering when using a no residue process. (added on 03-Oct-2004)
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© 2004 Daan Terstegge - All rights reserved. |