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Jan 6, 2015 | Lead free SAC solder paste on Sn63 HASL PCBs In switching to lead free processing, we find ourselves having over 400 PCB part numbers with Sn63 HASL finish. And there is no hope of quickly purging inventory and getting our drawings changed to call out a lead free finish. I want to avoid having to run 2 SMT processes, requiring 2 ovens mixing occurs? NOTE: I am not trying to make RoHS compliant assemblies; just want to avoid a 2nd oven during our transition period to a total lead free shop.
Mar 13, 2014 | You're creating a new alloy on the surface of your board. The alloy will have a melting point determined by the constituent metals of the alloy. Your alloy consists of: * Lead-free HASL solderability protection on the board * Lead-free solder paste * Solderability protection on the components that can be lead-free or not * Other stuff Your MP+10*C rule ["solder paste is that peak temperature must be with 10 degree higher than melting point temperature (219 +10= 229)"] is sketchy. You leave no room for variation. For instance: How tight can you hold that 230*C peak of your oven? I suggest
Mar 1, 2013 | Lead free wave solder alloy The LF wave solder solder alloy that marketing-types of other LF wave solder alloys compare themselves to is Nihon Superior SN100C
Feb 28, 2013 | Lead free wave solder alloy Hi All, after many years of talking about it we WILL be setting up a lead free line. What alloys and products would you recommend. We are seeting up a new wave machine here soon and could us some input.thanks
Nov 6, 2012 | Ryan ... "As for bismuth-based lead-free alloys, a lower melting temperature than that of tin-lead is offered together with a cost similar to that of tin [in the area of $3/lb]. Unfortunately, bismuth in soldering alloys tends to create embrittlement, and if a bismuth-based alloy picks up any lead , the melting temperature will drop again, causing joint embrittlement. At first glance, the bismuth bearing alloys appear to offer high tense strength, but in peel strength test they are prone to failure due to poor fatigue resistance. The same can be said for indium-based lead-free alternatives ." [Understanding Lead-Free Alloys, Karl Seelig 1/98] More detailed information can be found in "Advantages of Bismuth-based Alloys for Low Temperature Pb-Free Soldering and Rework" Brook Sandy, Edward Briggs and Ronald Lasky, Ph.D., Indium Corporation, First Published at SMTA's International Conference
May 2, 2012 | The surface tension of lead free solder alloys doesn't self align as well as it does with leaded alloys. Taking the guesswork out of alignment would negate the need for expensive split vision systems and make the parts hand reworkable.
Mar 8, 2011 | Lead-Free alloy determination in repair / rework transistor circuitry and on to SMT and other technologies. During that evolution was the development of the various alloys of solder and their drawbacks 60-40, 63-37, multi-core fluxes, lead-free. I hold master and instructor certifications for soldering, in the mid 70's I helped develop the solder . With the adoption of RoHs controls and the subsequent use of many different alloys of lead free solders, (at least 6 I know of), the following comes to mind: 1. Are there compatibility issues mixing between the various alloys of lead-free employed currently in electronics manufactures? 2. How does
Dec 22, 2008 | I wanted to hear from users of the SN100C alloy to find out what they think is positive and negative about this lead free alloy. Thanks, Keith SN100C alloy positive and negatives
Dec 12, 2008 | Greg, I totally agree with you that machine settings are very important in wave soldering and soldering in general. I disagree that lead free alloys can produce wetting like in the attached picture (leaded alloy). Lead free alloys have a much higher resistance to flow and much higher surface tension compared to leaded alloys. Therefore lead free alloys have higher wetting angles and all other associated problems related to poor wetting behavior.
Dec 5, 2008 | Every problem faced with (all) lead free alloys can be solved with 2 words �add lead� I'll keep it short don't want to sound like a broken record. lead free 0603 wave soldering
Mar 18, 2008 | consumption of lead free solder alloy SN100C What volume of boards are you putting through. 1Kg per hour does sound very high but then again it does depend on volume Using an antioxidant is a must with Lead Free some alloys have additions in them to start with but those drop out with use so the rate of dross increases rapidly. A good supplier will offer you antioxidant to run with it. As a general rule of thumb if you use a good antioxidant then dross rates for Lead Free are half that of Leaded solder if it is running higher then you may have a golden/yellow colour to the solder and dross will increase. Cheers Greg BLT
Mar 14, 2008 | consumption of lead free solder alloy SN100C Hello Could somebody inform us about real consumption of lead free solder alloy SN100C on your wave solder process. We do not use some antiaxidant and had had alloy consumption about 1 kg per hour. What is your experiance? All sugestion will be wellcome Peter
Nov 9, 2007 | We are using SAC305 for reflow and SN100C for our selective solder.
Nov 8, 2007 | Ok, thanks for the input.
Nov 7, 2007 | Lead Free Alloy HS laws as soon as aprill 2008. I am a small company that can�t afford an expensive trial and error migration to lead free, looking for the correct alloy to switch to. I would appreciate input form companies that use the Sn99.3% and 0.7Cu % lead free alloy, in the long term �is it the best option ? the alloy with Ag is very expensive, I�m sure it must be a better choice, but tin whiskers are my concern, besides higher temps and all, I don�t wish to have problems with my products in a few years...
Aug 6, 2007 | Hi Gents, I heard people having concernes by using 2512R SMD resistors due to potential solder joint reliability defect(CTE mismach among ceramic/alumina+solder+PCB) when soldered by lead free alloys (SAC like). Any experience/news about solder joint reliability of 2512R when soldered by Lead 2512R Lead Free Solder Joint Reliability Free ? Thank you Best Regards...GSx
Jul 16, 2007 | D. Hillman, et al., �The Impact of Reflowing a Pb free Solder Alloy Using a Tin/Lead Solder Alloy Reflow Profile on Solder Joint Integrity,� International Conference on Lead-free Soldering, CMAP, Toronto, Ontario, Canada, May 24-26, 2005, lead free components in leaded process ="_blank">http://www.CMAP.org Jasbir Bath, et al., �Reliability Evaluation of Lead-free SnAgCu PBGA676 Components using Tin-Lead and Lead-free SnAgCu solder paste,� Proceedings of 2005 SMTA International, Chicago, IL, http://www.smta.org. Pan, et al., �Lead-free
Apr 17, 2007 | IPC Conference Raises New Lead-free Reliability Concerns Now, they realized the problem of the current leadfree alloys. Is there any leadfree alloys finalized to use in future? Will it be a four elements alloys instead of current three elements alloys (eg SAC)?
Dec 2, 2006 | analysis nitrogen vs amount of dross No increase of the dross formation is recognized: ||Air kg dross||Nitrogen kg dross SnAgCu 260*C||2.00||1.27 SnAgCu 270*C||1.90||1.37 SnPb 250*C||1.92|| There will roughly be twice as much dross generated with lead-free alloys. SnCu will dross slightly more than Sn Best dross remover is to not produce dross. Search the fine SMYnet Archives for previous discussions Dross will not increase signicantly * Another story, that lead-free solders will generate a greater volume of dross than conventional materials, is also known to be incorrect. Cookson Electronic 's laboratory work confirms that lead-free solder dross generation is not statistically different from lead solders. However, there are significant issues to be confronted, and manufacturers will find that lead-free processing is somewhat more demanding overall than conventional tin/lead solder production
Oct 31, 2006 | Use lead-free alloy wire during rework for Leaded Process Can someone advise if there is any risk if we use lead-free alloy wire during rework for Leaded Process?The reason for this proposal is to only have one type of solder wire being used in the line.This will eliminate any possibility of leaded wire being used on a Lead free board.
Jul 18, 2006 | This RoHS has created a new "underworld" of brokered parts --- parts dipped in Lead-Free alloy to pass as "lead free." I could see some guy with a fur coat and feathered boa hawking lead free parts on the street: "Check it ouuuttt...I got lead free transformers, capacitors, and resistors, and I
May 12, 2006 | Steve, You're asking the right questions, don�t listen to sales pitch and stick with the facts. But you're in for a tough ride with lead-free because there is just not enough data and experience with the lead-free alloys as of yet. Every month you hear of a new miracle alloy. I believe there are now about 30 lead-free alloys out there and even more patents pending. Anyway when they get to the 50th alloy I hope the industry will get the point. You still remember how many alloys we got a couple of years ago? Ok enough for today I don't want to end up at the bottom of the lake with lead-free
May 2, 2006 | I also heard that fluxes are more agressive in lead free alloys. Try maybe to clean your tip more often ?!?!? Tip life of soldering irons with lead-free (SAC305)
Mar 2, 2006 | Lead Free High Temp Solder Wire Your best bet would be to browse through you current solder suppliers catalog and pick your alloy. Most of them have a list of alloys and their melting points as well as what form they can be supplied in.
Feb 24, 2006 | Lead Free The No-Clean indium lead free paste runs well. We discontinued because of extremely high shipping costs. We can get the same results with cheaper product. Almost all of the discussion in this forum about SAC305 and SN100C have to do with wave soldering by the way. You were talking about Indium Corp. as opposed to an indium alloy?
Feb 21, 2006 | Dear all, Recently our lead-free samples being rejected due to very dull and sometimes grainy and very porous surface on solder joints. This samples was flow thru' the lead-free wave soldering with SN100C alloy composition. Referring IPC-A-610 D, lead-free solder may produced dull, matte, gray
Feb 17, 2006 | with lead-free solders, one would expect to find less instances of tombstoning. this is because SAC alloys are not eutectic and melt over a range of temp (usually 217-220 deg C) instead of at a single temperature. therefore the forces due to solder surface tension are more gradual lead free and tombstoning
Feb 14, 2006 | Yes, it's fine - as Pete says you have to replace certain parts & either get the pot recoated or a new one. We ran a "Lead free" 6622C from Vitronics Soltec on Tin Lead, then it was cleaned up, recoated and loaded with a no-lead alloy with no problems. Tin-lead wave soldering using a lead-free machine
Feb 13, 2006 | Hello, I know for sure that using lead-free technology in conventional tin-lead machines makes a lot of problems. But I wonder if we can use conventional tin-lead alloy and components with a lead-free machine! Is it possible? Does this imply any special measures, precautions or modifications Tin-lead wave soldering using a lead-free machine
Jan 27, 2006 | Kester is offering a tin/copper alloy for lead free. Any comments regarding using just tin/copper as opposed to tin/silver/copper or tin/nickel/copper? the price is low but why wouldn't everyone else offer just this alloy as opposed to the standard SAC305? Lead free tin copper only
Jan 20, 2006 | . But if you measure resistance by surface probing, the lead free alloys oxidize significantly faster compared to leaded alloys and since tin oxide is an insulator you will see an increase in resistivity. Resistance Shift with Lead free Steve, How do you measure the resistance is it by probing the surface? Concerning the alloy there is a straightforward linear correlation between the tin content and the electrical conductivity of the alloy. The higher the tin content in the alloy, the better the electrical conductivity
Jan 19, 2006 | ? and or suggestion for lead free alloy that will not have this effect? Resistance Shift with Lead free Any metalurgists out there? I take the resistance value of a metal oxide substrate made of silver or gold or manganese. I then solder with 63/37 and the resistance changes but not dramatically. I then solder with Lead free SAC305 and the resistance changes immensly. Any suggestions as to why
Jan 11, 2006 | Lead Free Dross What alloy are you using in your wave? SN100, SAC305, SACX?
Jan 5, 2006 | USING LEAD FREE PARTS WITH LEAD PASTE The CCGA packages that we install are still a tin/lead alloy and not a SAC alloy. They were 90/10 SN/PB. I beleive that this may be one reason why the difference.
Dec 10, 2005 | options in reworing this package? I am thinking that Sn63 paste must be used. Should I create a profile for Sn63 or lead free alloy to melt the balls of BGA as well? USING LEAD FREE PARTS WITH LEAD PASTE How about this scenario: Need to rework a BGA on a 2 year old board. Originally the board was assembled with Sn63/Pb37 and the BGA has eutectic spheres. Now this package only comes with lead free balls. I believe that the board finish is not ideal/ compatible for lead free reflow. What are my
Dec 5, 2005 | I hate to sound like a broken record but the industry has been placing lead free through-hole parts forever. Now all of a sudden its a problem??? Gold finish, silver, silver paladium, alloy 42, even pure copper. Reliability will be a function of the components you select, its metals composition was transitioned from tin/lead to lead free and both part numbers had MILLIONS of placements with no record of fillet cracking (during manufacturing). Used in tin/lead = no problems. Used in lead free = fillet cracking. Turns out the problem connector was using a different pin alloy than its cousin. cte Lead free compatibility
Nov 11, 2005 | for Tin/Lead Alloys, nothing jet regarding Lead Free Alloys. Did I have seen correct? Thank you Best Regards.............GS HI all, which is the last "though" about the max Pb % allowed/acceptable into a Pb Free Alloy ? For istance inside : - HASL Process Solder Pot Alloy - Wave Solder Pot Alloy ( 400Kg mass average) - Static Wave Solder Pot Alloy - Etc IPC-J-STD-001D talks only about Solder Purity Limits
Nov 2, 2005 | Lead-free solder alloy: Bob Gilbert, could you pls email me the reliability data for joints made with SN00C and SAC305 alloy. my email: email@example.com
Oct 14, 2005 | Mika, If I understand you correctly you compare hole fill of Ni/Au plated boards in a lead-free process with HASL 63/37 boards soldered with leaded solder. If this is the case you might be facing the challenges in Pb free wave soldering with the limited wetting characteristics of lead-free alloys compared to leaded alloys.
Oct 12, 2005 | , or are these impurities not important anymore? These metals are dissolving about a 100 times faster in lead free compared to leaded alloys. The European government with the help of sales people does an excellent job in brainwashing and makes us believe we have been chasing ghosts for the last 30 years. A minority can Yeah, adopting is the right word. In this new lead-free era spec.'s are made to stay within the scoop of the RoHS directive. The driving force for spec.'s should be reliability. Did you see any impurity level spec.'s yet in wave soldering for Cu, Au, Ni, Zn, Fe etc. in lead-free only rule when creating chaos and confusion and this is exactly what is going on with lead-free. Just wanted to state some facts, because no clear answer is available in lead-free "yet"
Oct 1, 2005 | Sorry theres a mistake on previous question. It should be lead free component termination but non lead free solder alloy Sn63/Pb37. The reflow profile i am using : Soaking temp. 120 to 160 deg C; time 90 to 120 sec. Peak temp. 215 to 225 deg C; time 60 to 90 sec. The question is there any metallic joint between the teminals of the component with the solder alloy. Please advice.
Aug 12, 2005 | To all smt neters, In many different threads I have tried to bring awareness of the dangers lead free alloys pose to the reliability of solder connections. Many times those warnings have been waved by unscientific reports (from lead free solder manufacturers) comparing their lead free alloy of preference to their competitors lead free alloy of preference. No positive report exists comparing lead free to standard leaded material. All literature in lead free is written like, if you get the disease learn to deal with the symptoms. Until today I was thinking being the only one aware of the dangers Report on lead free
Aug 10, 2005 | Bob, Great theory if you're selling SN100C, but I have to disagree that an alloy being 4�C off eutectic will cause cracks. When a solder joint exits the solder wave, there is an immediate drop in temperature of 100�C. so being off 4�C is irrelevant. Lets not forget that lead-free is still in its very early unexplored stage, and nothing can be stated as fact. One of the biggest differences between leaded and lead-free alloys is that leaded alloys are ductile and lead-free alloys are brittle (more susceptible to cracks). When a board passes over a solder wave there is a tremendous amount lead-free alloys (independent of composition). Reflow will not have this phenomenon because the board is not thermally stressed as much as in wave soldering. The reason why the cracks are formed on the topside of the board is: When the board warps when heat-shocked in the wave the PTH is stressed
Jul 28, 2005 | Lead-free solder alloy: reported in the 5 plus years of production (>300 million boards to date). I also have some reliability data for joints made with these 2 alloys wave soldered and then repaired with both. All of these results look good. The issue we see is mixing SN63 with any of the lead free alloys. Sn63 wave soldered joints repaired with lead free and lead free wave soldered joints repaired with SN63 show some incompatibility in our thermal cycling and cross sectioning tests. A cd with these reports is available upon request. Regards, Bob
Jul 15, 2005 | Lead-free solder alloy: If you do SMT with an SAC alloy, and the Wave Solder with SN100C, what is the impact of accidentally reworking the through hole parts with an SAC alloy wire solder? Or reworking the SAC alloy with an SN100C wire solder? Brian
Jul 14, 2005 | Lead-free solder alloy: Chris, The Asahi SCS7 is Asahi's attempt at copying the SN100C and is a tin/copper/silicon alloy that melts at 227C so no, it is not a low temperature lead free alloy.
Jul 12, 2005 | JBC is offering "Lead free" tips now. They have this on the web site: "JBC recently released a new series of tips featuring a thicker iron bath that we find more resistent to aggressive additives and flux as found in lead free alloy." We have not done enough lead-free soldering with the original soldering irons for lead free
Jul 12, 2005 | A while back we checked out all our manufacturing equipment for lead free capability, we thought our soldering irons would all be fine as they can reach temperatures well in excess of lead free alloy melting points. Last week i was speaking to someone who told me that i'd best be carefull soldering irons for lead free as if the irons dont have enough power to hold the temperatures then to solder we'd need to up the temperature, which would cause the tin in the alloy to be more aggressive and we'd be going through tips every few days. Our irons are JBC 2200 and are rated at 55W, has anyone else looked at this
Jul 12, 2005 | Lead-free solder alloy: Hi Bob, I heard that they have low temperature solder that is able to tackle heat sensitive component. Some of my industrial friend also mentioned that they some sort of low cost material alloy -SCS7?? Is that true? Thanks Chris
Jul 12, 2005 | Lead-free solder alloy: Sorry to contradict your suggestion but the Asahi 300 series alloys contain indium which is both very expensive and has very limited availability.