Typically if the white residue is on the solder, if a piece of wetted silver chromate test paper is placed on the residue for a minute, chloride or bromide can be detected by a change in the color of the paper from tan to white (chloride) or yellow (bromide). Most commonly copper salt is green and the white reside turns out to be lead chloride. Looks like corrosion to me. Lead turns dark over time, tin turns white. Looks like a mix of both; perhaps the solder's just breaking down. Probably from random stuff in the air over these decades (nitrous oxides, water as humidity, etc.) Notice that the tracks are solder-coated (wave soldering), but they all appear fine as the green solder resist has prevented air from reaching them
soldering operations to reduce heat input, and reviewing the supply chain of the soldering materials to identify a flux which does not cause white residue problems. Tin Oxide reaction residue Tin Oxide reaction related white residues are caused by a reaction between the Solder Tin and the activation acids within the flux (pics inside) GPU PCB has white marks/residue around solder points. Dangerous or Not? (pics inside) GPU PCB has white marks/residue around solder points. By If left on solder joints(and there might be some present), it can be corrosive and destroy the solder joints over time. Not to strike fear into you or anything At this moment in time we are using water soluble solder paste on our PCBs these are cleaned using water only, agitated with ultrasonics. After drying a white/grey residue is left around solder joints. Reflow profile is fine and a reliable wash procedure is followed. Advice would be appreciated. reply Â This is white residue around all the SMT pads and on the bottom selective wave solder areas. This is flux that is reacting with moisture and may be conductive or is benign but we must prove it. Please contact me off line and we can discuss your conditions in detail
A clear, greasy-looking residue around a solder joint may raise flags for your customer's incoming QC inspectors. If the flux residue chars and forms spots on the solder joints, it may look like a true defect like a solder joint void or blow hole The white stuff (sometimes feels fibrous like cotton candy) is just efflorescence. This is from dissolved minerals in the water precipitating out as the leak drips, then dries and deposits miniscule quantities of calcium, sodium, etc on the valve body Once the ceiling was opened up I see that our copper water piping has some green residue only on the joints. I was doing some research online and seem that the conclusion is mixed, some say not to concern while other think that it needs to be fixed. There is one or two drops of water on the joint where there is green Key words: circuit board cleaning, water-based cleaning, thermal oxidation, rosin, PCB component board . In the electronic process technology, PCBA (circuit board or circuit board) often whitish after cleaning, and the white mark is scattered around the solder joints, which seriously affects the appearance acceptance and brings quality hazards Re: white residue after wash. Electronics Forum | Fri Apr 03 08:22:36 EST 1998 | Scott Cook. At this moment in time we are using water soluble solder paste on our PCBs these are cleaned using water only, agitated with ultrasonics. After drying a white/grey residue is left around solder joints. Reflow profile is fine and a reliable wash pr
The most likely source of white powdery residue around solder joints on printed circuit boards (PCBs) is the formation of insoluble metal salts from the solder flux. Lead or other solder metal rosinate, abietate, or other organic acid salt tends to form when soldering temperatures are too hot Cleaning Flux and White Residue proble chemical difference between a flux that leave white residue and one that does not. The acid carboxyl group also reacts during soldering. Because tin can also be detected in the white residue, a portion (less than 10% by observation) of the reside may be a reaction product between tin oxide and the resin acids. The result is often referred to as ti This month we feature one recent submission: white residue rings on BGA joints. All BGA solder joints featured a white ring around each ball termination. The ring was perfectly formed and not like normal white residue often seen from a standard cleaning operation. (Figure 1). [FIGURE 1 OMITTED] In fact, the ring consisted of solder paste.
residue were also characterized. In this PCB, white residue was predominantly consisting of tin, oxygen and chlorine, which was formed due to corrosion of ï¬‚ux residue under high humid conditions. The damage around soldered joints of stored PCB board was found to be due to re-soldering, over heating which cause The store tells me it's nothing, and if anything, just flux residue from production. To me, it looks like overheating. That is; a bad connection or something is causing a lot of heat, and thus these brown and dark spots around, especially the leftmost pin, and a black area on the edge of the PCB Halogen free solder paste formulas with SAC305 alloys are the most difficult of the new formulas to remove. It is very important to match the cleaning agent to the flux residue.This is likely a prime factor in why you are seeing the white residue or it can be as simple as not being at the recommended in-use ratio of your cleaning agent
carbonate residue around the solder joints. If not completely removed during cleaning, these ions can establish a continuing corrosion cycle, producing which will attack the copper in the board laminate. The best solution to the formation of ionic contamination is the clean the board thoroughly, as soon as possible, after soldering Repair: Sometimes the excess solder can be drawn off by dragging the tip of a hot iron between the two solder joints. If there is too much solder, a solder sucker or solder wick can help get rid of the excess. Prevention: Solder bridges most often happen between joints with too much solder to begin with. Use only enough solder to make a good joint
4. You might simply be soldering too slowly causing the solder to melt too quickly in one place. See #5 if you think this is causing you difficulties. 5. It might be your solder type. 60/40 flows more easily than 50/50 and can cause soldering problems if you go too slowly. You could try soldering the backside first with 50/50 then turning over. Guide to Solder Mask Discoloration. Careful inspection of your printed circuit boards (PCB) may be second nature in your industry, and the first time you saw solder mask discoloration on a circuit board, you may well have been alarmed.. Whether you observed white patches on a PCB, dark stripe PCB solder mask discoloration or some other type of solder mask discoloration, it's natural to. A green moldy looking substance may develop on your copper water pipes, especially at the joint. Typically, this green discoloration is a patina, which develops from plumbers not cleaning away excess soldering flux after joining pipes. Many homeowners mistake the green discoloration for mold The white soldering flux residues are located near and between soldered joints 26 a to 26 h. The solder joints electrically connect electrical terminals 28 a to 28 h, to electrical leads 29 a to 29 h, respectively. The white soldering flux residue regions 24 a to 24 f can be created, during the solderin
i have noticed after cleaning boards w/ 91% ISP that there is a white residue on the components and slight haze on the board. my process is to clean the board before hand w/ 91% ISP, not handle components by any leads and most of the time i am placing them by tweezers as they are smd (qfn, tqfp, 0402, 0603, etc) and to only touch the board on the sides, not near any contacts. to clean, i use a. White residue around the periphery of the solder bump is a common concern with cleaning flip chip assemblies. These residues are composed of fluxing byproducts consisting mostly of unreacted soluble organic compounds and a small amount of metal salts of tin that are highly stable in inert (Figure 3) Soldering (AmE: / Ëˆ s É’ d É™r Éª Å‹ /, BrE: / Ëˆ s oÊŠ l d É™r Éª Å‹ /) is a process in which two or more items are joined together by melting and putting a filler metal into the joint, the filler metal having a lower melting point than the adjoining metal. Unlike welding, soldering does not involve melting the work pieces.In brazing, the work piece metal also does not melt, but the filler. Y White haze over surface Z Faint residue on surface, but improved over W, X, and Y A Gratuituous white waxy residue, especially around solder joints B Waxy residue C Waxy residue D Waxy residue E Washed clean. No residues F Washed clean. No residues G Washed clean. No residues I Washed clean. No residues
. I also saw green rust stains. Could be an action of flux residue. Try washing one of the joints. Reach4 It might only leak once inawhile. Im pretty sure if your pipes frooze at one point, it will stretch the solder joint and weaken it... this would cause. No-clean solder paste is more accurately described as low-residue solder paste, says Dixon. After reflow, the flux leaves a small amount of noncorrosive, resinous residue on or around the solder joints. This residue varies in color from transparent to amber, depending on the reflow temperature and the flux resin
I have found that if a joint was left uncleaned for a few days after soldering, that the flux residues form a white cover over the joint, which eventually turns green, and this most surely is a chemical reaction between the flux and the copper or solder. It may well be eating into the joint, making it weaker . You might find residue around solder joints after soldering, this is burnt flux. While it's not conductive, nor has any negative impact on the performance of your solder joints, it's a good idea to clean it nonetheless. Simply wipe the residue off with a cotton swab dipped in alcohol. Some Other Resource Yea this is the tuner chassis from a Curtis Mathis royal dane but the mold problem is also on some wires on the output transformer as well. I know I can't replace those (I guess I could clip them and solder new leads on) the white stuff is only on some of the cables so I assume it is either mold/stuff secreting from the insulation
Following the reflow process, the flux leaves a small amount of residue around the various solder joints. There are several reasons to remove no clean flux residues from PCBs. Historically, no clean fluxes were developed as tacky resins which inherently coated and stuck to all surfaces. The residue would gradually build up on the test pins Solder joints are seldom quantified for their reflectivity properties. Traditionally, solder joints are characterized Increased levels of flux residue browning on a white solder mask can absorb light, thus affecting the brightness of the luminare. The probe is a 6-around-1 bifurcated fiber bundle with six incident fibers and on residue sources (e.g. board fabrication, SMT paste flux, waver solder liquid flux, hand solder flux or a completely different, possibly unauthorized, source. Key Words: Ion Chromatography, IC/MS, chloride, sulfate, weak organic acid, spot extraction. Introduction . Changes in technology and electronic assembl Keep going until the seam in the joint looks full all the way around but don't overfill. A handy rule-of-thumb we heard somewhere says to match the length of solder you use on a sweated joint to the diameter of the pipe - a half-inch of solder to do a joint in half-inch pipe, Â¾-inches for Â¾-inch pipe and so on
We perform dozens of failure analyses every month for our clients in various industries and identify many different root causes of failure. One that can be difficult to identify and prove is soldering flux residue. As circuit designs shrink and become more complex, flux residues are more likely to cause failure from leakage current Cleaning flux from a solder joint also allows for proper inspection (no copper exposed). Using a cotton swab or acid brush (cut, as Pete stated) soaked in alcohol helps to break down and remove.
At The Harris Products Group, we sell a lot of brazing and soldering alloys. Over the years we've noticed some misunderstandings about the importance of flux in producing a quality brazed joint. This blog entry explores the five most common misconceptions about flux Having made hundreds of solder joints using it, I've seen none of the problems that are reported with other solder pastes. It is a mixture of tin/lead balls in a suspension of flux, and the flux also works well. it leaves a crusty white residue around all of the SMD components. I don't know what the difference is in the formulation as the. Thoroughly clean and smoothen the joint. By using a brush, apply the paste flux to the top of the joint. Turn on the torch and start heating the joint evenly. Do not directly heat the paste. The flux will then start to spread around the solder. At this point, you should cautiously move the torch from side to side
resulting in a weak solder joint. Therefore, as an alternative, hand soldering is performed using astandard lead containing solder assisted by excessive use of ''No clean hand - soldering flux. The purpose of the flux is toact as a wetting agent and surface activator during the soldering process Soldering (pronounced /ËˆsÉ’ ËŒdÉ™r ÉªÅ‹/) is a process in which two or more metal items are joined together by melting and flowing a filler metal (solder) into the joint, the filler metal having a lower melting point than the adjoining metal. Soldering differs from welding in that soldering does not involve melting the work pieces. In brazing, the filler metal melts at a higher temperature.
Soldering (AmE: / Ëˆ s É’ d É™r Éª Å‹ /, BrE: / Ëˆ s oÊŠ l d É™r Éª Å‹ /) is a process in which two or more items are joined together by melting and putting a filler metal into the joint, the filler metal having a lower melting point than the adjoining metal. Unlike welding, soldering does not involve melting the work pieces.In brazing, the work piece metal also does not melt, but the filler. If the solder resist is thin, solder can wet during wave contact and leave a ball. Figure 4: Solder on a resist can wet during wave contact and leave a ball. Solder balling during wave soldering has always been around, but the elimination of cleaning after the soldering operation has made it more visible as a process problem Visual a nd SEM Inspection of Solder Joints before Cross-Section Appearance Optical and scanning electron microscopy under low magnification showed many whiskers and hillocks protruding through flux residue, and also growing from solder without flux residue (Fig.1). The whiskers and hillocks we observed had different size If the solder was insufficiently removed, resolder the solder joint with new solder and try again. Best use for a desoldering gun. A desoldering gun is most useful when you need to desolder a large number of through hole components, and using solder wick or a desoldering pump would cost too much time . Traditionally, solder joints are characterized Increased levels of flux residue browning on a white solder mask absorb lightcan , thus affecting the brightness of the luminare. range of 3501000 nm. The - probe is a 6-around-1 bifurcated fiber bundle with six.
Don't feed too much solder into the joint. It's tempting to melt a few inches of solder into a joint as extra insurance against leaking. But excess solder can puddle inside pipes, restricting water flow, and can form small balls that break loose and damage faucet valves. Use about 1/2 in. of solder for 1/2-in. pipe and 3/4 in. for 3/4-in. pipe The solder should appear shiny when done. If it is dull or has a brown residue on it the joint did not achieve proper temperature and is called a cold joint. Cold joints are what makes most cheap electronics from China fail fast or not work at all. If your solder joint looks like I described it go back and heat it up again With a solder ring joint, the joint is heated until a ring of molten solder is visible around the edge of the fitting and allowed to cool. Of the three methods of connecting copper tubing, solder connections require the most skill, but soldering copper is a very reliable process, provided some basic conditions are met Based on the in-situ observation and X-ray analysis of the black residue, we envision the soldering sequence of epoxy solder paste with the formation of black residue as a function of temperature, as shown in Fig. 9. When stencil printed at room temperature, the epoxy solder paste exists as a mixture of Sn-58Bi solder particles, flux, and epoxy. WS-446HF. WS-446HF Flux is a robust, halogen-free, water-wash flux that was designed to provide one simple solution to complicated applications, especially those with a single cleaning step for both BGA ball-attach and flip-chip processes. It has a powerful activator system to promote good wetting on even the most demanding substrate metalizations such as Cu OSP, ENEPIG, and ENIG
. Cosmetic Appearance: The classic tin-lead solder joints were shiny and smooth. In fact, a defective solder joint often had a dull, rough appearance. This is not the case for lead-free solder joints, which have a less shiny appearance As for flux type, the no clean still leaves a residue and is not easy to remove but isn't harmful to the board. If you look at some modern commercial electronic items you may see a white residue around the soldering, that is the no clean flux. I used it only a little bit years ago and didn't like it. Might be better now
A 5 month old new Arrieta 570 20ga has white residue that appears on either side of the rib along the barrels. the salts will weaken the solder joint and at some point the rib will come loose. Soft solder melts are a low temperature, around 450 F if I remember right. Then comes silver solder which melts at much higher temperature and. You state about the solder where the rail joiners were, so I take these are removed from an old layout. It could be just the look of the solder after cooling improperly. While usually a cold solder joint will have a grey dull appearance in some light it could look white. Over all you may be happier with new switches Let the tinning product melt around the tip, then clean it as above with brass wool or a tip cleaner. Repeat the steps above until the tip is clean and all the oxidation has been removed. Correct solder flow should return to the tip once it is properly clean. Functionally Clean. You may notice some black residue from the flux, especially on the. Because lead-free solder contains flux, once soldered, it can leave residue around the solder joints. This can be removed using isopropyl alcohol (IPA) and a clean, lint-free cloth. Give part to be cleaned a quick spray with the IPA, and then rub it with the cloth to clean off the residue
7. Slowly add a few millimetres of solder to the other side of the joint. DO NOT apply solder to the soldering iron tip. If enough heat was applied to the PCB padand component wire, the solder will ow freely onto the joint. Figure 1.2: Method of Soldering Through Hole Joints 8. Remove the solder when the joint is suitably covered as shown i White Powder around Gas Vent White Powder around Gas Vent. By fqp25, July 5, 2008 in That's the white crud that appears at B-vent joints when water condenses in the flue. It's an indication of bad venting. we would still see a bit of this white residue over time. So..... this residue is NORMAL for the type of heater in question.. The optimal choice of alloy depends on the type of surface to solder and the application for the flexible circuit. Cosmetic Appearance: The classic tin-lead solder joints were shiny and smooth. In fact, a defective solder joint often had a dull, rough appearance. This is not the case for lead-free solder joints, which have a less shiny appearance 2. If your solder wick does not have flux on it, it would be a good idea to add flux to the section you are going to use to make for a clean removal. 3. Place the braid over the joint you want to rework. 4. Place a hot soldering iron against the braid and desired pin. 5. Wait a few seconds. The solder will flow off the pin and onto the braid. 6
The after is to remove the flux, which is mildly acidic (?) and, over time, will attack the solder joint. 2) I should use the type of isopropyl alcohol that you get in the paint section of Lowes or Home Depot (which is ~95% alcohol), and NOT rubbing alcohol (which is 50% alcohol, 50% water) Tanaka et al. 144 investigated the effect of flux residue on the ECM of Pb-free solder alloys including Sn-3.5Ag, Sn-9Zn, Sn-5Bi, Sn-0.8Cu and Sn-37Pb solder alloys. The samples were first solder-plated, then coated with flux, and finally heat-treated using reflow processing conditions None of the procedures are specific to Flexible circuit soldering, but most of the temperature settings for hand soldering in general range around 600 deg F (318 C). My personal experience is that 600 F (318 C) is sufficiently hot to complete most of the solder connections required in hand soldering Everything from the visual inspection of a solder joint to the elemental analysis of an observed board surface residue, SEM/EDS obtains information that other analytical techniques simply cannot. Both SEM and EDS can be used for evaluating and / or analyzing samples whether it's simply for screening purposes or for a failure related issue
As a starting place, for most small electronics soldering, 1/32 inch (.03) rosin-cored, 60/40 (tin-lead) or 63/37 solder should work fine. Rosin-cored lead-free is fine, too. Unless you have reason otherwise, don't use no-clean solder-it's very likely that you don't need to clean the regular rosin-cored solder. The solder should be thin enough to prevent [ Flux pens come with several different types of flux. Some pens like the Kester #2332-ZX are excellent at getting the solder to flow and make very nice joints. But it must be removed. What it leaves behind can keep you circuit from working. The residue from other flux pens can be left on the board with no ill effect However if the solder paste is a low/no residue nitrogen reflow solder paste delamination does not occur. Figure 6. Paste 16 (low/no residue) Pre T Shock. Figure 7. Paste 16 Post T Shock/No defects. The following are a series of photographs that identify the hard flux issue with delamination of a harder urethane coating. Photo 1 . The second part of this case talks about how many white residues are conductive but not corrosive, and often come from un-cleaned flux reacting with water or from. I just wanted to give you some feedback on the FCT type 4 lead-free solder paste. I tried it and was pleasantly surprised with the result! The material spread well, printed great (nice defined bricks, even on the fine pitch square apertures). The solder joints looked great and had very good pad wetting
Ensuring a Clean Solder Joint at every stage in the soldering process, it's essential to avoid contaminants. You can start by cleaning the piece in an ultrasonic before soldering. In addition, follow these steps to ensure the cleanest possible solder joint: Remove all polishing residue from your fingers before fitting a joint You'll likely have some joints with too much solder. A piece of solder wick will remove the excess. Often, just that operation will result in a good joint. However, sometimes you'll have to melt the solder joint again and add a small amount of additional solder. SMALL is the operative word The paste form is ideal for soldering TUBE joints. Not recommended for electrical or electronic applications due to the potential corrosive residue of the flux. Stay-Clean past flux works well with most leaded and lead-free solder compositions. Flux residue should be removed after soldering
Flux assists heat transfer from the source to the solder joint area, allowing the solder to contact the base metal surface. Residues that originate from flux may also affect electronic functioning circuits. For instance, flux left around IC leads can cause electrical leakage between leads, resulting in shorts Lead-free solder alloys have been around for as long as people have done soldering, with sources dating back about 5,000 years. Most of these alloys were combinations like copper-silver or silver- Solder is drawn into the joint by capillary action and a bead of solder will form around the joint when it's filled. When the bead appears, you know the joint is completed. 5. Be careful when wiping away the excess solder and flux residue that is left on the joint. Although the pipe may appear to be cool, always use a damp cloth to remove the. Though with RA and RMA fluxes, I'd still remove them anyway, just in case. I use Kester 245 solder for all my repair work, which has a no-clean flux core, so that I don't have to worry about it. Though I do use a lot of liquid flux for de-soldering, particularly if the old solder looks like it's heavily oxidized
Plain copper bits don't last well, especially at higher temperatures, (as, with every joint, some copper from the tip dissolves in the solder unless it already contains around 2-3% copper) but you should be able to get enough extra life out of it to tide you over while you order and wait for the spare bit you should have had in stock Pure unleaded tin has a melting point around 230 C. That's high, but not terrible for PCB assembly considering a typical lead-free solder profile peaks around 250C. Meanwhile, some metals, tin included are prone to whiskers where ultra-thin barbs grow out of the solder joint and can cause shorts. Toyota learned about this the hard way. That. Cut your solder into tiny slivers (I mean tiny). Yes, I did reference needing magnification at my age, especially. Place the solder pieces along the joint to be soldered. Using a small butane torch/pen/Blazer/whatever, apply heat to the underside of the joint. In a second or two, the solder disappears into the joint - emphasis on disappears When the joint is full of solder, the solder will automatically form a bead around the joint. You don't have to run the wire solder around the joint. Just hold the solder at one point and let the capillary action do the work. Step 7. Let the joint cool by itself. You should not dip the soldered end in water because this sometimes causes the.