Order by: Relevancy | Date
Aug 14, 2018 | Vlad, Reduce your aperture opening in the stencil, this will give the stencil a good seal around the specific area of concern. In a wave solder environment, solder balling top or bottom surfaces in a wave pallet is caused by excessive flux burning off too quickly or becoming trapped. Once the pallet/PCB hits the molten wave, a bunch of miniature explosions take place that creates solder balling. Maybe a combination stencil & profile?? My stencil Guru here at my Oregon facility can assist you if needed, reach out to me offline if needed...
Mar 6, 2018 | Thanks.,
Feb 28, 2018 | Stencil-less printing? MY500 on a NPI/Proto line makes a lot of sense and can really cut down on costs and downtime due to stencil revisions/issues. Especially once you have a 250 line BOM loaded on the line and you find out the stencil has a couple of critical apertures incorrect, change the MY500 program and keep running, or reorder the stencil and either tear down the entire job, or hold up an entire line for at least a day.
Mar 1, 2016 |
Feb 3, 2016 |
Jan 28, 2016 |
Feb 11, 2015 | stencil/printing machines for solder paste I can buy approx 1000 stencils (cost includes next day delivery) for the price of a MY500. With a stencil, I can use WS paste and any other paste for that matter. The MY500 only jets certain paste from specific manufacturers. It is VERY VERY rare that we cannot get the proper solder volume with a stencil (the first time) and we have over 2000 active SMT assemblies. The MY500 is a great idea but I just cannot understand how it could be cost effective in any arena at this point.
Aug 10, 2014 | Thanks
Aug 1, 2014 | Check attachments.
Nov 5, 2013 | Stencil Life Identification I track all of our production daily in an excel spreadsheet that I use to calculate the OEE. I added another tab and use it to automatically calculate remaining stencil life of each stencil. I replace my stencils after 25K cycles, (prints). Things to take into consideration, I chart my production in single assemblies, so I created a formula to revert these back to panels. Then I use an If/Than statement to trigger a cell flag from "Safe" to "Order Stencil", (changing the color of the cell to RED, when the stencil life falls below 10%). =IF(Q5>10%,"SAFE","ORDER STENCIL") I like tracking it this way
Oct 17, 2013 | But where does it go, that it needs to be refreshed or replenished on the stencil? Does that "just like wax" product wind up in my solder joints, no matter how small the percentage, and would it then qualify as a contaminant? I heard there are some (nano)coatings that are baked on during the production of stencils, and some are wiped onto the stencil by the end user. Those wipe on products I worry about just a little, as in, where does it go that it needs to be replenished on the stencil? I think that bears some thought. Maybe someone with expertise on these coatings can chime in, maybe
Feb 18, 2013 | We have some Vectorguard stencils and frames. I am having issues with one of the frames. And need a little guidance. A stencil is on the frame, and we can't get it off, the operator heard a pop while putting the stencil on the frame, now we hear air while trying to remove it. I have repaired this frame in the past, replacing one of the inner hoses, but cannot repeat the magic. I know I need to isolate on which side the air leak is...can't tell as it sounds as if its coming from a corner or two. Main thing is getting the stencil off without damage. Any ideas would be most appreciated.
Feb 15, 2013 | Small apperture release from stencil Hi MikeS, I didn't post all the information, because I didn't want to mislead you. I wanted to see your way. We tried 3mil and 4 mil stencil using type 4 paste. It was hard to get the right aspect ratio and that;s why we did it on Nickel stencil - aspect ratios are different for Nickel stencil
Dec 15, 2012 | solder paste stencil life Normally paste manufacturer specifies stencil life of a paste is 10 hours. the question is, if i run a continuous manufacturing for 40 hours, we will be adding 250 g of paste for every two hours. The addition of 250 g will be mixed with the paste which is already available on the stencil. After first 10 hours of manufacturing, do we need to remove all the paste in the stencil and scrap it?, currently the practice is we keep on adding till the end of production. since this goes by addition mechanism, there may be molecules of paste which has applied 12 hours before. any thoughts in this?
Jul 5, 2012 | The PCB has 9 QFNs, distributed arround the whole board, but the ones in the edges are the ones with the problem. My stencil is 0.005" (I use to have a 0.006"), yesterday I realize after talking to my vendor that the stencil is manufactured in 2 steps because the frame does not fit into the machine , so they cut half the stencil + rotate the frame + cut the other half, I'm guessing that may cause such inaccuracy... dont you think so? anyway I will send the stencl and a board the them to check if the PCB or stencil is according to gerber file.
Nov 17, 2011 | What is the best way to keep ESD totes clean? We use both the blue static dissipative and black conductive ESD totes to store/transport our electronic assemblies. Our problem is that they get dusty/dirty and periodically need to be cleaned using ESD cleaner and a paper towel. Being that human nature isn't what it should be, rarely do people take the initiative to clean their totes before use. Some people lay a Kimwipe on the bottom, but doubt that this is acceptable from an ESD standpoint. Since reminding has failed, one idea was to get a "dishwasher" of some type to clean small batches regularly, but what type of detergent
Nov 16, 2011 | I am currently using a water wash batch cleaning system, closed loop. I am looking for a better result when cleaning and thinking of introducing a chemistry. What is the best chemistry to use? Will using a chemistry to clean actually provide a better result? Thanks, Jared B.
Aug 31, 2011 | Cleaning Vapor phase or vapor degreasing cleaning for electronics is simple technology that holds merit on process situations like you described. Easy and quick to set up and process with today's modern equipment you can be up and running in no time once the machine is on your floor. The hard part comes from matching the flux to the cleaning solvent. Many of the newer flux and solder paste formulas used today are very resistant to vapor phase cleaning. OA flux formulas are out as they do not clean with vapor phase cleaners. To compound this flux selection process the number of available vapor
Aug 26, 2011 | What is the best method for cleaning PCBs I am looking for some guidance concerning cleaning PCB's. We are bringing in house our circuit boards and need to clean them. I am not sure what the best method is. Is it Ultrasonic or Batch wash. If someone can make some comments one way or the other that would be appreciated.
Jun 29, 2011 | Hello all I have used a couple of types one of them only clamped on two sides and you used a wrench and screwed the bolt down till it was tight ( what is tight) and there was no fram at all around the stencil so people got cut. the second one we used uses air pressure to do the clamping and pulls from all four sides much better and has a plastic fram around stencil so no one gets cut by the stencil takes more space but i can fit two plastic framed stencils in one spot the full fram used so it saved me some space Goog luck
Jun 24, 2011 | PCB Washing No Clean My company is currently looking for a closed loop system that we could use for batch washing of PCBs. We primary use no clean flux and are looking for a system that we can use to clean the residue? Most likely we are going to have to add an additive like Alpha's 2110. Any recommendation
Apr 22, 2011 | Beaker Scale Testing for flux cleaning chemistries/surfactant Hi, I am doing my master degree in flux cleaning process for flip chip assemblies and required to establish a new receipt for flux cleaning. currently, i am doing screening process for the parameters involve ; temp,pressure, surfactants, speed and angle of penetration using inline cleaning machine . Is there any other ways to evaluate the chemical compatibility for flux cleaning instead of directly tries it using the cleaner machine? It will be a waste to use lots of chemical just for screening. I have found a paper that use beaker-test-scale method for chemical compatibility (Cleaning RMA Flux residue
Aug 21, 2010 | The paste you dispense will not solder the same as the one you use with a stencil. The paste for the stencil will have a higher metal content. I was not working with dispensing as small as you are, but after evaluating the cost of the stencil vs. longer run-time on the machine when dispensing , keeping multiple viscosities of paste, and the cost of the dispensing equipment, I decided the stencil was still the best solution for me (even with proto runs). This is just what I decided for my shop and doesn't mean it is the best solution for yours.
Aug 10, 2010 | I'm having problems with Quad QSP-2 pick n place machines recognizing fiducials. We are cleaning the fiducials, but that's tedious and time consuming ( I don't know anyone who routinely cleans them). We have solder mask clearance around the fiducials. Any suggestions so we can stop cleaning
Jun 16, 2010 | Conformal Coat over No-Clean A customer wants to coat a no-clean assembly to cut cost and cycle time. I know what wave flux I can use to make it work, but the Indium SMQ92J paste we use causes dewets. Any other no-clean pastes out there that play nice with acrylic?
Apr 28, 2010 | Vapor/ensolve flux cleaning then switching to a water based cleaning system or not cleaning? Thanks in advance!
Mar 31, 2010 | PCBA Cleaning rags We are looking for lint free rags to clean our circuit boards with. We use these when processing no-clean flux the operators will use a de-fluxer apply it to a rag and use a brush along with the rag to pull the flux from the board. Does anyone have a good source for lint free rags? saponification
Feb 23, 2010 | Mixing No-clean and water soluble processes Is there any harm in washing SMT soldered with NoClean paste? The PCA has some large thru-hole connectors that we would prefer to do as water soluble on out selective solder but the SMT consists of LGA's and other low parts that we would not be able to adequately clean under. The wash is strait DI
Feb 5, 2010 | oil contaminated PCB cleaning the board in question is from Foba Laser Engraver, it's a surface contamination coming from.. everywhere, a lot of moving parts that are lubricated. I'm now studding chemicals that we may use for our kind of rework & cleaning. We may think of modifying a dishwasher to change the washing cycles to suit better this kind of cleaning. Or may be we buy a Trident System, ;)
Jan 26, 2010 | Cleaning Copper Surface what made us to try it? after testing most general degreases including some electronic degreasers in spray can from reputable manufacturers without having success in achieving a clean and shiny (no stain) surface. we do not want to re-etch or use etching solution to clean it so that's out from
Jan 26, 2010 | Really Need Electroplishing of SMT Stencils? Dear SMTNetters: Based on your experiences is it really necessary to have today's YAG laser-fabricated stencils electropolished? I undertsand that this "requirement" is a carry-over from the days of CO2-fabricated lasers where the hole wall quality was less than desirable......... (There is some strong opnions on both sides of this argument) We use a SS stencil for small proto runs of less than 20 pcs, most thicknesses of stencils is 4-6 mils in SS. For UFP we are using nickel. Your comments are welcome.....
Nov 25, 2009 | The design of the opening apertures for the glue stencil and the metal thickness.Its is very important. The Engineer of the stencils supplier have to look into the height of the components and the gap of the 2 leg(pads)and give the assemly house an suggestions what stencil thickness should be used 0.007" or 0.008" or 0.010" You can contact me at email@example.com. I can look at your gerber files and help you to create the glue stencil work perfectly for you.
Nov 17, 2009 | Anyone else?
Nov 12, 2009 | Stencil Printer? appears to only carry the clam-shell type. If you look carefully at the photo of the ZelPrint you will see the PCB on the left hand side. The PCB has a thin film of polycarbonate pulled across it for alignment. The PCB (and polycarb) is slid to the right under the stencil and then lifted up to the stencil. The stencil does not move. After you squeegee the paste onto the board (covered with the polycarb) you lower and move the board left, back to the starting position. Now you can do a good alignment of the board by using the left-right, up-down, and rotation knobs. Because the paste
Sep 25, 2009 | Stencil thickness 0.5mm pitch QFP's are typically mixed with large components on all of my boards. I usually use a 6 mil stencil with a minimum aperture width of 10 mils. Normal aperture size is 10 x 50 which causes shorts about 20% of the time. A recent purchase of a used LSM height measurement system shows paste height of 7.3 to 8.2 mils. To compensate for the additional paste height, I could go to a step stencil for the QFP, reduce the aperture to 10 x 40 or go to a 5 mil stencil and take a lot of time increasing the paste on the rest of the parts. What are you doing to solve this problem.
Aug 26, 2009 | The blue tint could be the result of etching of the tin in your solder connection during cleaning when using a slightly basic cleaning solution. Just about anyone can duplicate this by running a board 7 or 8 times through a cleaner with a saponified cleaning solution. What is the alloy
Jun 16, 2009 | Hi, If your using NXT to place these BGA's then you must be doing large runs. BGA's are the most easy part to place, and don't worry about them. Just stencil paste down for them as any other component. But we use 1:1 reduction on our stencil, so we don't get paste release issues. Also, we use electroform stencils, as DEK make them cheap, and they are so much nicer than any other type of stencil we have used so far. Don't know why you would want to use just flux, on such an fast line, when pasting them will be ok. Grant
Jun 2, 2009 | Stencil Design I was hoping some-one would help you with this because I too would like more information about selecting stencil thickness. I have read some about apperature ratios, but this alone doesn't appear to be the only factor when chosing stencil thickness, ie. when you use a full apperature vs. a home -plate modified apperature. Can anyone recommend where to find more details on selecting stencil thickness? Thanks.
May 15, 2009 | We implemented an inexpensive home dishwasher solution last year for cleaning assemblies. It works very well for both lead free and tin/lead cleaning. DI water at room temp is all we do and the boards come out squeaky clean. We had to use the least expensive machine with a mechanical timer so we
Jan 2, 2009 | Water cleaning and Moisture Entrapment Thanks for the reply Stephen. The time factor sounds logical for moisture invasion during cleaning, probably why there's no articles showing concern about the process. I did try experimenting with some samples and believe it or not could not duplicate the failure; I even tried cleaning them
Oct 2, 2008 | Hello Ok there is not much info here. What you have to mae sure of is several key factors. 1. Have you entered the correct stencil thickness. 2. Are you using the stencil gerber (not the paste layer) The paste layer is usually not adjusted for appeture adjustment. 3. Does the machine you are using have zero offset adjustment in the programing and are you using it. 4. the last is what is the appeture ratio. This is the wall hieght to the appeture area. If you are doing very small appetures on a thick stencil the paste release can be very low due to higher surface tension on the stencil than the board. Jerry
Sep 2, 2008 | no clean flux + wave soldering issue if two boards with different solder masks give different results on flux residue level after soldering with the exact same machine settings than it is clear that one of the solder masks is not compatible with your no-clean flux. could be the solder mask is not cured sufficiently and parts of it interact with the solvent(s) of your flux. this types of residue is hard to wipe or clean off the boards. it looks like they are 'baked' inside the solder mask. use the solder mask that works.
Jul 25, 2008 | Wave Solder Pallet Cleaning Listen, fancy places and spending lots of money will never replace a good wave profile and a good scrubbing from the garden hose. Get you'r e act together and you need mininimal cleaning of the pallets. Then theywill just clean up well with a little elbow grease. but thats a grease most people
Jun 26, 2008 | Note for cleaning process I am a PCB Designer and I have to put a note on the assembly drawing to tell the assembler how to clean the board. This is new to me. Here is a sample note. Can someone give me some feedback on it? "Use water washable, no clean solder paste for the assembly. Wash in DI water following reflow
Jun 24, 2008 | Disposal of ultrasonic cleaning water We are purchasing an ultrasonic cleaner to clean pcb asseblies that have been produced with water soluble flux based solder. After cleaning a batch of assemblies, the water in the cleaner will need to be disposed of. My question is: Do we need to filter out the flux residues from this water
Mar 31, 2008 | Cleaning station installation reqirements Hi! May be somebody help me with links to materials or document`s for assign separate (separate room) installation of cleaning equipment from all another SMT line. p.s. some managers of my company want to install solvent based cleaning units in same room as main SMT process and soldering line
Mar 20, 2008 | In addition to Dave�s comments RE: Stands for RESIN (purified or modified rosin) No resin can be cleaned with pure DI water (requires saponification). L0: Stand for halide free activation which can safely be left on the boards. To my knowledge all activators that qualify for L0 are not soluble in pure DI water. All flux types ending in L0 according J-STD-004 are no-clean/ low residue and are not formulated for cleaning.
Feb 13, 2008 | cleaning anodized panels Our front panels (where the controls show) for our assembled amplifiers are anodized and we make sure that it is free from oils or other stains prior packing the whole assembled unit. We just use damp cloth in cleaning and sometimes flux remover for hard to remove stains. Is there a better way of cleaning anodized panels without damaging the printed letters or color of the panel? Appreciate inputs
Feb 3, 2008 | Cleaning procedure when WS609 flux is used Won't argure with you Davef, but guys who suggest totally unnecessary steps to resolve a cleaning problem drive me NUTS!! What would the moulding compound manufacturer have to do with it? HIS BOARD IS NOT CLEAN!! Keep it simple, get the job done! Don't fall into paralysis by analysis...you'll never
Jan 21, 2008 | Cleaning procedure when WS609 flux is used Just what is delaminationg during testing? Water washing should be sufficient to clean WS609. On the other hand, it's possible you're conveyor speed is too high to do a good job cleaning the high density areas. What kind of testing have you done to assess the cleanliness of these areas?
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