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 Aug 16, 2005 |
... processRx_6-04.pdf http://www.residues.com/pdf/white_residue1.pdf http://www.residues.com/pdf/white_residue2.pdf Regards, Sara Foresite Inc. (765)457-8095 www.residues.com
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Jul 12, 2004 |
... made up of a base of alcohol which�s residues can be cleaned off with water. Water Soluble: A water soluble flux is one that its base is made up of water and by so can be cleaned easily with water. Resin-Free No Clean: A �No Clean� flux containing no Rosin elements. It is mostly a synthetic resin which residues are non-corrosive and non-sticky. No Residue Flux: A flux which has no residues left on the board after the soldering process. The residues are evaporated. High Solids Flux: A flux ...
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Aug 10, 2004 |
... Because the HASL process most deal with bare metals, HASL flux residues are generally more active than solder paste residues. Typically a Rosin Active (RA) flux is used in the HASL process. These flux residues should be removed from the bare board. Though with a really thorough examination, some level of HASL flux residue is identifiable on many boards. For NON-SMD pads, the solder mask does not cover up the HASL flux residues which may remain at the base of the pads. Therefore, any HASL residue ...
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Aug 16, 2005 |
White Residues Hello, I have a question on white residues formation at wave soldering. We have recently run experiments to test the performance of various halide-free water soluble fluxes (ORH0 under JSTD-004). The flux was applied through a spray fluxer and all PCAs were immediately washed after wave soldering in in-line cleaner, with DI water only. Surprisingly, we've identified several PCAs built with flux A from one vendor exhibiting white residues at various T/H leads on the boards. See ...
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Jan 6, 2006 |
... about green contamination - http://www.residues.com/pdfs/foresite_green.pdf If you are concerned with finding out just what is there and what the cause is, I would agree with davef that it would be helpful for you to consult with an independant laboratory. Regards, Sara Rice Foresite Inc. www.residues.com ForesiteInfo@residues.com 765-457-8095
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Jan 18, 2007 |
... solder paste: Different no-clean solder pastes will leave different types of (benign) residues. If your paste has been qualified from a Bellcore/SIR/Electromigration standpoint, any residues remaining will NOT ever cause problems in the field...EVER! Some typical areas that flux residues pool up: 1.) Around chip components. 2.) Around fine pitch IC Leads.. 3.) The DPAK Heatsink area... etc.. Flux residues will also look... 1.) brown and gummy. 2.) flakey 3.) or gummy transparent.. Again it ...
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Dec 13, 2004 |
... residues, and long term reliability is compromised if residues from incoming bare boards, components, or un-solublized flux residues are not dealt with. It is critical to control these aspects of cleanliness since a no clean process is not meant to go through cleaning, and cleaning is very difficult if a residue is discovered after assembly. To see some studies on this topic, visit our website at http://www.residues.com and look ...
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Dec 13, 2004 |
... on how ROSE testing correlates (or doesn't corrlate) to actual board cleanliness and long term performance, take a look at a correlation study we have on our website, http://www.residues.com. Visit http://www.residues.com/pdf/phoenixdata.pdf to view the study. If you have more questions, contact us offline through this board or our website ...
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Sep 22, 1999 |
... board. This creates several potential problems: | | � In some applications, like high frequncy, the no-clean flux residues can interact with circuit functions. | � No-clean flux residues can interfer with automatic test probes. | � Some people don't like the appearance of flux residues. | � Conformal coating of boards with no-clean residues requires more care. | | Further, no-clean fluxes have a narrower soldering process window than washable fluxes, increasing the cost of soldering and ...
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Mar 28, 2006 |
Flux Residues In Lead Free Wave Soldering Process Thanks for the input Guys Yeah the not so knowledgable customer does not like to residues for cosmetic resons. The flux is for lead free process, of the no clean and water soluable type. We have explained to him that technically the residues do not post a problem since it has no impact on the SIR etc. We even provided him with a white paper on the white residue issue. Stil �%*(&/&(//( My test guys of course do not like me either but understand ...
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Mar 27, 2006 |
... Residues In Lead Free Wave Soldeing Process When you say "unacceptable" do you mean cosmetically unacceptable? I've always put as much flux (no clean, of course) on the board until the ICT guys start yelling at me. That's how I roll... Lots of factors with no-clean flux residues...board mask (glossy is worse), flux type (alcohol or water based), and the obvious, flux deposition amounts. We all know, no-clean flux has a low-solids content, has past electromigration testing, etc, and that residues ...
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Jul 28, 2009 |
... is to remove the flux residue. Be aware that the residue you see does not represent all of the assembly’s residue. All no-clean processes leave residues behind. The challenge is to determine if the residue to harmless or harmful. Spot removal is not recommended as you are only removing the visible residues. If you have a concern that the residues may be harmful, a defluxing process may be in order. As ironic as it sounds, more of our customers remove no-clean fluxes in their defluxing systems ...
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May 25, 2008 |
... is that there was no white residues formed on wave solder or hand solder joints. So those white residues should be a chemical interaction between the flux in the solder paste, detergent and DI water. We have changed and tried the solder paste from Multicore, Alpha and Qualitek, the residue concentration has changed, lesser with Qualitek may be but still there. I will be appreciated any comments that you can send me for helping me to get rid of those white residues and find a solution to have ...
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Apr 4, 2003 |
... opaque, thin / thick film, hard / soft, color white, etc] * Where are these white residues located? [eg, pads only, solder mask only, every where, etc.] * What is the scope and extent of the problem? * What is your process, process materials, board fabrication, and process settings? Q2: Why do some white residues pass ionic contamination tests and other white residues do not pass? A2: White residues are chemical compounds. Chemical compounds can be either ionic or nonionic. Ionic contamination ...
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Sep 21, 1999 |
... This creates several potential problems: � In some applications, like high frequncy, the no-clean flux residues can interact with circuit functions. � No-clean flux residues can interfer with automatic test probes. � Some people don't like the appearance of flux residues. � Conformal coating of boards with no-clean residues requires more care. Further, no-clean fluxes have a narrower soldering process window than washable fluxes, increasing the cost of soldering and material control ...
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May 25, 2010 |
Help with dewetting Where on the assembly is the dewetting occurring? Factors that influence dewetting usually involve non-ionic contamination such as: * Residues from board manufacture including silicone surfactants from solder resist & HASL rinse contamination * Component residues like mold release agents * Silicone oil from adhesives in production. * Soldering process residues * Cleaning bath contamination where rinsing has failed * Operator handling that adds contaminants
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Mar 25, 2006 |
Flux Residues In Lead Free Wave Soldeing Process Hi, sounds unusual if your profile is accurate that you have so many residues. Had a similar problem before with no clean flux and with various flux manufacturers, and all residues were down to excess flux. This does not help your case though. How are you measuring your parameters? loz
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Mar 25, 2006 |
Flux Residues In Lead Free Wave Soldeing Process Hi You all We use no clean flux in our lead free wave soldering process and have unacceptable residues. The provile is spot on. If I reduce the flux amount the holes won't be filled and border on the IPC II specs. The customer does not accept partial hole fill even if it is IPC II acceptable and at the same time he does not accept the flux residues as well. Cleaning is out of the question since the cost added is to high ...
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Mar 16, 1999 |
IPC-A-610B Section 5.0 Cleanliness In Section 5.1 Flux Residues, 5.2 Particulate matter 5.3 Chlorides and Carbonates & White Residues, I am assuming that these boards have been through some type of cleaning step. Hot water, saponifier, air dryed and the pictures illustrate unacceptable results. I have noted the "No-Clean" flux exceptions. Are my assumptions correct ...
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Sep 2, 2009 |
ionic residues on the surface of printed circuit assemblies You can determine empirically what will work. * Use ion chromatography [IPC-TM-650 2.3.28] to evaluate the residues and determine if the residues must be removed. * Use energy dispersive spectroscopy for the elemental analysis or chemical characterization of the residue ...
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Sep 1, 2009 |
ionic residues on the surface of printed circuit assemblies Hi davef, Thanks for the suggestion. I have inspected the heaters but I think they are OK (no visible coating, deposits, etc.). Unfortunately, I'm not sure that the residues are ionic. It was just preliminary report of the person responsible for the process. I have made a visual inspection of the printed circuit assemblies once more and I think that the residues look more like fur and/or calcium carbonate (see the pictures). I hope that ...
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Sep 8, 2008 |
... Assembly? http://www.residues.com/pdfs/Circuits%20Assembly%20Articles/2003/low%20res/2003.01-Can%20You%20Clean%20a%20No-Clean%20Assembly%20-%20Circuits%20Assembly.pdf Component Cleanliness in a No-Clean World: White residues
May 26, 2008 |
White residues It's possible that the flux residues from the solder paste used in your SMT process is not compatible with your water wash process. For instance, some no-clean fluxes leave resudues that are not water washable. When these residues are washed, they develop a milky white coating on the solder connection ...
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Mar 20, 2008 |
Solder Paste You need to use speial cleaning solution to clean the residues from no clean pastes. Alpha has a solution,(I think Alpha 2010)that can clean no-clean residues. Zestron is another company which specializes in cleaning no clean residues. contact Alpha and Zestron www.zestron.com
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Jul 10, 2007 |
... Search the fine SMTnet Archives for more. Q2. What are the chances of the kapton tape adhesive leaving behind silicone residues on the COB pads? A2. Depends. Kapton tape is not the same as kapton tape. Some tapes leave no residues, but they cost more than those that do leave residues. Guess which one buyers choose, when left with a choice? Q3. If silicone residues are left behind, how to get rid of it? A3. Dow claims that the OS series of solvents (VOC-free) will remove silicone oils. Contact ...
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Aug 1, 2006 |
Cleaning OA solder core residues with alcohol Does anybody knows if there is any reaction if I clean OA solder/flux residues using Isopropilic Alcohol? Is there any chemical recomended to clean residues manually instead of using a washing machine ...
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Jul 6, 2005 |
How to improve the solder quality of QFN? Jason, If you have any pictures of this phenomena that might be helpful for the forum to see in helping diagnose your problem, you can send them to me and I can post them on my website to view. My email is sg_foresite@residues.com Sara Gorcos Foresite Inc. www.residues.com
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Apr 27, 2005 |
Flux residual on joints of PIH Hi Sarag, We share Sara's described experience with cleaning No-Clean/Low Residue flux residues. We can add that of the Low Residue residues, Indium SMQ92J is one of the more challenging flux residues to clean. That said, we have had repeated success with this cleaning process. Should you decide to consider cleaning as a standard process or for the batch of boards produced so far, we would be happy to speak with you about our experiences and try to help you with ...
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Jan 21, 2005 |
no-clean flux removal Hi esoderberg - I was wondering if you had tried altering your soldering profile to try and fully solublize the no clean flux residues and elimate your cleaning dilemma? You can check out my company's website if you want some free reference materials on cleaning and contamination - http://www.residues.com
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Jan 2, 2003 |
... the quantity of (possibly) entrapped residues under them is also small. When averaged over the whole area of the board (both of the existing methods do that), the results would be quite (probably falsely) acceptable. Entrapped residues from soldering operation are very corrosives when left on the board. To evaluate if they are there, we will lift components from the boards, (create access for evaluation), but we also need a method to test for residues in a specific spot, not just an average over ...
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Apr 28, 2002 |
... motherboards with some buses exceeding the speed of 100MHz . we use no clean flux and it is OK even with the residues you can see under a microscope. But according to our own experience through a modification for more than 1000 boards, the flux residues remaining after manual rework are very critical. Tens of faulty boards passed all normal & burn-in tests just by cleaning the residues of the No Clean Flux. According to what I understand, N.C.F. means it is not harmful to your components & PCB ...
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Apr 22, 2002 |
White residues Greetings All, Anybody out there experiencing white residues after cleaning? We currently use a batch cleaner to clean water soluble fluxes. this cleaner makes its own DI water by means of carbon and resin tanks. After cleaning there are residues on all of the solder joints. They can be brushed off but will not come off with subsequent washing with either alcohol or water. We have tested the boards with an IONOGRAPH and the level is good but customers don't like it much and ...
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Aug 12, 1999 |
... both smt/reflow and wave soldering, but we get troubles with defects rework; | | | | | does anybody know how to eliminate flux residues or how not to produce them during rework operations? | | | | | Thanks to everyone. | | | | | g.d. | | | | | | | | | do you mean that u r having residues from your no clean process? | | | | and that during rework u produce residues? | | | | try changing to other flux, solder or solder paste supplier. | | | | during rework u need to use no clean stuffs too... if ...
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Aug 10, 1999 |
... process, both smt/reflow and wave soldering, but we get troubles with defects rework; | | | | does anybody know how to eliminate flux residues or how not to produce them during rework operations? | | | | Thanks to everyone. | | | | g.d. | | | | | | | do you mean that u r having residues from your no clean process? | | | and that during rework u produce residues? | | | try changing to other flux, solder or solder paste supplier. | | | during rework u need to use no clean stuffs too... if this is ...
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Aug 10, 1999 |
... clean process, both smt/reflow and wave soldering, but we get troubles with defects rework; | | | does anybody know how to eliminate flux residues or how not to produce them during rework operations? | | | Thanks to everyone. | | | g.d. | | | | | do you mean that u r having residues from your no clean process? | | and that during rework u produce residues? | | try changing to other flux, solder or solder paste supplier. | | during rework u need to use no clean stuffs too... if this is already ...
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Jun 30, 2001 |
ECOs on OSP finish Consider using a roll solder with a flux that well matches the residues you can accept to be remaining on the board when you get finished processing. Many people use a no-clean flux cored roll solder for such operations, because they don't want to clean the residues and NC flux residues are relatively benign. Go to Circuit Technology Center [http://www.circuittechctr.com/guides/guides.htm
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Jun 14, 2001 |
Wave Soldering Flus Selection Hi, I read an article that says "Flux selection usually depends on the following factors": a) Solderability of pcb base metal or coating b) Corrosivity of vapours and residues c) electrical resistivity of residues d) Ease of removal of residues e) Soldering Temperature Now, can someone explain to me regarding the above factors on "Why flux selection depends on the above 5 factors. Is that all I need to have a look when selecting flux for our Process ? Thanks in ...
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Jun 12, 2001 |
effective liquor for cleaning the residues in reflow oven As you know there will be a lot of residues(such as rosin) left especialy on the peak zone and cooling zone of reflow oven after reflow soldering in a time. who use one kind of effective liquor or effective method to clean the residues ...
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Jun 12, 2001 |
... will depend on the test method you select. For minimum requirements, look at J-STD-001C, Para 8, "Cleanliness Requirements". I figure that you�d measure the residues on a lot of your current product, measure the res on a lot of your product using NC, and be happy if the res from your NC is lower than your older flux. Ionic residues are detectable by: * Resistivity of Solvent Extract (ROSE) testing (Omega meter, Ionograph, etc.). [Eurolanders call this Solvent Extract Conductivity (SEC).] Using ...
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Mar 30, 2006 |
Flux Residues In Lead Free Wave Soldeing Process Hi Fellas After bangin my head several times on the cold and hot solder pot nothing improoved. The residues still bother my customer. I agree with less is better but if we apply less we have a cleaner board but the solder won't flow all the way up. Back to the beginning. Thinking of increase the airpressure of the spray fluxer (air velocity) and at the same time reduce the flux volume so to achieve better penetration and yet reduce flux volume ...
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Aug 17, 2005 |
White Residues Dave, Answers to your questions: * From your pictures, the white residue appears to be only on the solder mask. Is that correct? If not, what is the location [eg, solder, nonsolder/nonmask areas] of the residue that doesn't show well in the pictures? Further, is this strictly a second-side problem? The areas with noticeable white residues were on solder side, solder mask only, and around all T/H leads. * You say that the white residue appears after washing, what temperature were ...
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Apr 14, 2000 |
... the amount and type of residues present on a printed circuit board at the very beginning of a SMT line depends on the exposure of the board up to that point. For instance: * Process used to fabricate the board. * Processing and handling after fabrication and before SMT. So, how was your board processed and handled to the point of concern? I would surprised not to see ionic and non-ionic residues on your board. Possible sources of these residues are: IONIC RESIDUES: Salts from etching and plating ...
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Dec 1, 2000 |
... betwwen fine pitch comp. Curious, very curious ... Residues � Where are these residues? [solder & laminate / mask, solder only, laminate / mask only] What is the result of your analysis to the residues? How do you know it�s a flux residue, rather than a chemical by product of the flux and metal oxides? Why isn�t this residue forming during the soldering process when the temperatures are presumably higher? Or could it be: the residues are forming during soldering and they are just becoming ...
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Jan 19, 2006 |
... There are other versions being studied, but that is the only version available to market currently. If you want further details, my best suggestion would be to either contact Eric Camden in our lab at ec_foresite@residues.com - he'd be happy to discuss the data with you & send pictures, or get in touch with P Kay Metals directly. Whenever I hear any more information about MS2, I'll post it here. Sara Rice Foresite Inc. www.residues.com
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Jul 14, 2005 |
... paste boards? Here is a link to a specific article about cleaning no-clean assemblies: http://www.residues.com/pdfs/Clean_No_Clean.pdf Our facility does a lot of contract cleaning and cleanliness testing for various companies around the world, and that study should give you a good base synopsis of what to do and what to expect when cleaning a no-clean assembly Sara Gorcos Foresite Inc. www.residues.com
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Apr 27, 2005 |
... t want to change pastes, you could look at modifying your profile to make sure the flux residues are fully heat activated, or you could even look at cleaning these residues if they are harmful or don't pass your visual criterion. No clean boards are more challenging to clean, but are indeed cleanable. If you have any other questions about the issues you are having, please contact us offline. Regards, Sara Gorcos Foresite Inc. 1982 S. Elizabeth St. Kokomo, IN 46902 (765)457-8095 www.residues.com
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Apr 19, 2010 |
... PA 19113; 610-362-1200 F1290 info@aciusa.org * Bodycote Materials Testing , 847-676-2100, na.bodycote-mt.com * Foresite 765-457-8095, http://www.residues.com * Precision Analytical Laboratory, 765-455-1993, http://www.precisionanalysts.com * Process Sciences, Inc; 10960 E. Crystal Falls Pkwy, Suite 400 ...
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Mar 19, 2010 |
No Clean and Underfill No clean pastes leave more flux residues. These can result in void formation and inhibtion of underfill curing. Selection of an underfill that is compatible with the flux residue is important. One company that has written about the effect of flux residues on underfill is Zymet ...
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Feb 24, 2010 |
... profile also was used (standard or lead free)? Anyway, white residue formation is known to occur after PCAs are cleaned in an aqueous cleaning system where the water temperature is relatively high (> 60° C). Moreover (by IPC standard)... "White residues resulting from no-clean or other processes are acceptable provided the residues from chemistries used have been qualified and documented as benign...". So, use an EDX or IC analysis in order to qualify the final result... XPS analysispcb.com
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Nov 21, 2009 |
... to 90% Dave, I would only agree with you when you talk about low residue (water based) fluxes. In low residue (alcohol based) fluxes you can use non water soluble acids, so in the event you still have flux residues on the board water has no effect on them. And I assume with OA you mean water-soluble flux. These residues can do damage to the boards even without elevated humidity, these acids are all hydroscopic by nature and have to be removed from the board. Have a great weekend, Patrick
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