Order by: Relevancy | Date
Apr 9, 2018 | Possible to mix a No-Clean solder and a Clean solder process definitely don't mix clean and No clean. Run No Clean as you decided, but have your flux and paste manufacturers advice, how this flux can be cleaned(if you decide or required to clean). I know for a fact that some of these NC flux residues are almost impossible to get rid of.
Apr 5, 2018 | Possible to mix a No-Clean solder and a Clean solder process We recently got a batch wash machine that can use a chemical cleaner. (not a saponifier). NOW I feel confident cleaning no clean boards. Without a machine that can heat water and use a proper cleaning agent, I would not trust cleaning no clean boards. You can add no clean steps after the last wash . But without proper equipment I would not have SMT no clean with wave water wash. For a long time I've said that no clean should have been named can't clean.
Jul 26, 2015 | as to its eventual commerical aims (if any). ENIG if your product can justify the cost is by far the best option for PCB finish. It is flat, clean and stores well. Most paste manufacturers will happily send you a pot to try for free. That way you get to put the paste through your process with your products. Nobody else can really tell you what will work best for you. There are several alloys out there for lead free process but by far the most common is SAC305. Most manufacturers will offer this in a no-clean variant. In the UK at least getting non no-clean SAC305 paste is actually often a special order requirement. I wouldn't concern yourself with looking for extreme detail on flux properties. If the paste uses the right alloy and has the cleaning poperties you require the flux will have the properties required because if it didn't it would not be fit for purpose. Instead you should look
Jul 25, 2015 | I am looking for information regarding setting up an SMT assembly line. I have recently purchased a stencil paste printer, pick and place, and reflow oven. The main information I need is the paste selection and best finish material on the PCBs. I will be wanting lead free, no clean solder and from
Dec 1, 2014 | stencil Yes nano coating giving the good printing, but the stencil tension is very important for the life, 1st ensure the stencil tension...
Nov 25, 2014 | three areas where I have to focus: a) paste printing - design of stencil, snap-off, understencil cleaning quality, solder paste coalescence parameter (I am not sure how could I check it). b) material impact - solder mask, I heard that roughness and surface tension could also have impact of amount Could be. I am making overprint to achieve proper amount of solder paste inside hole. Now I am trying to reduce maximum overprint and compensate it with step - up stencil. This could reduce effect that some particles of solder paste are not gathering together and occurs randomly on PCB
Nov 4, 2013 | Stencil Life Identification Hi, How can the life of the stencil be decided? As the stencil is used contineously the thickness go on decreasing. How are you all deciding the life of stencil? As visually its dificult to deide the solder paste deposited thickness, is there any tools being used to check the stencil thickness
Feb 22, 2013 | I don't know, what you have, but I just got back from the IPC APEX show and I'll make several points: * One take away about 'nano ...' is that it means different things to different people. For instance, in stencil printing: ** DEK uses Aculon and it is a flux repellent ** LaserJob uses Siemens in the selection and qualification of materials. * Further, recognize that some forms of this stuff can be an environmental and health hazard. * Be careful, from a process stand point, your cleaning chemistry has to be pH neutral or you'll kill this stuff. * Finally, I'm concerned that nano ... becomes snake oil
May 17, 2012 | Underscreen cleaning cycles with Fiber lasers over 6 years ago we now have 10. Nano I have been working for approx. 4-5 years. PHD and FG we introduced to North America 5 years ago and is now availabe to most stencil vendors. I developed the Eform Process the same time as Xerox..benn eforming since 1993. Also team leader on building
May 11, 2012 | Underscreen cleaning cycles Diode laser. This is the most sought after stencil today. Although I am seeing an interest again in Eforms.
Mar 22, 2012 | board if you wish. A nice feature is you can program the machine to inspect only every X board if you wish. You can copy and paste inspection areas on panelized boards too. As for cleaning the machine can be set up to clean itself after X amount of boards AND/OR after an X amount of time AND/OR if a of inspection. It will continue to inspect the 2nd tier of components until your placement machine calls for the board. Then it will stop inspecting and pass along the board. You can program your own fiducials for boards and stencils. You can add a paste verification to avoid putting a board in backwards . And the machine gathers a myriad of data that can be used for SPC or CpK study. The one thing about the new MPM platform is you will need an engineer to set a lot of your criteria up ahead of time. We did not like the under stencil wiper paper feature. It shows you how much paper is left by a percentage
Mar 4, 2011 | 01005 stencils Does anyone have any recomendations on 01005 stencil aperatures? Stencil thickness?
May 19, 2010 | HI Im new to this but i thought i would have a go at fixing my xbox 360 be re balling it,ive managed to remove the gpu and take all the old solder balls of and cleaned it up,then ive put it in a re balling jig with the 360 stencil fluxed the gpu with flux with a fine paint brush then let
Jul 13, 2009 | Stencil Fiducial Repair Here is something I found , I hope it helps : Subject: Re: Repair of fiducial fill material From: Taylor, Royce Reply-To: TechNet E-Mail Forum. Date: Fri, 15 Dec 2000 09:34:59 -0500 Content-Type: text/plain I use a epoxy pen that my stencil house gave me it says: HEAT CURE EPOXY INK AM-33 an ultrasonic stencil cleaners for our stencils. > It' work well, but after some time, we saw a lot of fiducial that the black > epoxy have been partially or totaly remove. I want to know if someone had a > similar problem with a stencil cleaner. Also, we looking for a material to > repair the black epoxy
Feb 18, 2008 | Inspecting a new stencil Most stencil manufacturers use an automated stencil inspection system like our StencilScan AOI that compares the Gerber data directly to the stencil image. We provide the StencilScan AOI system to end users that wish to guarantee stencil / screen and board accuracy and/or cleanliness prior to production. The system can also create Gerber data if the file is lost or damaged. Here is the product info: http://www.smartsonic.com/AOI-StencilScan.pdf Bill Schreiber Smart Sonic Corporation
Jan 15, 2008 | time at 40X, I'd go out of business. Who needs solder stencil printing and reflow soldering if you have to examine every single joint? After reflow, I give the boards a quick scan, only doing the chips and looking for shorts and obvious solder defects, and probing a few leads here and there for ones that move, ie. not soldered. I rework what is needed, then clean (high density only) and test. What fails the testing goes back for closer examination and rework. No, none of my gear goes into vehicles, aerospace or other life-critical systems. Jon
Dec 20, 2007 | I run a prototype/small-run shop, so I'll include some recommendations too: 1) Don't buy a machine for just what you are doing today. Once you get into this field you will find demand to do more. 2) Don't scrimp on the stencil & machine. You will speed up your production and get better results good job. I've placed 0.5mm pitch parts without grief. Support is also very good. 4) The oven is no less important. What good is pasting & placing well if you don't solder the boards properly? A big part of this equation is the solder paste. I prefer no-clean paste so that I don't have the extra step of cleaning. For SnPb paste I prefer AIM. The oven can easily be your largest power consumption. Be careful with oven specs as some manufacturers do not actually specify max current, but instead specify idle current. There's a big difference. Good luck!
Jul 13, 2007 | The Contamination has proven to be pretty random, lots of stainless steel though in fact two cases in the past two days. As far as I know all machinery is cleaned regularly as well, even the stencil washer itself. The boards we make are 90% (at least) Surface Mount Components, with maybe 2 or 3
Mar 29, 2007 | To use a mini stencil, or not to use a mini stencil. We always apply solder paste to either the PCB pads or the BGA balls. I have found that only using liquid or tacky flux does not always ensure proper wetting of the pads. Also The BGA sits closer to the PCB making cleaning and endoscopic inspection more difficult. Appying solder paste
Nov 28, 2006 | J Rose at EMPF says: The introduction of no-clean solder fluxes in electronics manufacturing has given rise to greater levels of solder balling simply because the opportunity to remove them in the wash process does not exist. They are typically caused by any one, or a combination of, the following : * Solder Beading. The result of solder paste squeezing out from under the component body during part placement. The solder trapped under the component body cannot wet to either the lead of the device or the PCB material. This condition can be minimized by changing stencil aperture design to limit paste the individual solder particles initially present in the paste. This condition is usually caused by cold or hot slump, paste deposit thickness and stencil cleanliness. * Solder Splatter. Occurs during reflow and is characterized by finding the solder balls far away from the pads where the paste was deposited
Nov 6, 2006 | Why a clean room? Or do you mean an environmental room to control temp and RH? Any way, to answer you question, your wave and oven can care less about RH. Just don't keep them at 100% RH. Static can easily be handled with lower RH and proper grounding techniques. Solder pastes should be able to handle anything that makes those human things comfortable. Follow any lead your paste manufacturer may offer. Then perform a DOE on paste stencil and PCB life. Document your results and set your times accordingly. Over all I would think anything in the 30 to 40 percent range would be just fine.
Nov 6, 2006 | production line. A paste�s �abandon time� is defined as the maximum amount of time between two printing cycles that will provide acceptable results without reconditioning or kneading the solder paste or cleaning the stencil. Printer downtime is typically due to placement problems or operator breaks. Solder Checks calendar ...nope not April 1st. -The fresher the paste the better the solder joint. Agreed - My dilema here is upper management wants the two lines to share one stencil printer thus saving the cost of purchasing a second printer. They propose to paste ahead, allow second runner to change stencils, paste their pc's, and so on. Is/are management process engineers savvy in the SMT process?? If so then they must know a little bit on failure analysis. - If shifts end approaches, they offer to store the pasted pc boards in a refridgerator overnight until population the next day. Only if you
Sep 15, 2006 | yes there is Caveman, (well maybe depending on your circumstances) you need to purchase a manual printer and print the connector then flip and print the other side. (you need a manual printer so you can print after the parts have nbeen reflowed, we cut stencil out ot allow for the cs and rs running this board with lead solder and water soluble flux we would handsolder it (drag tyechnique), but pb free and no clean impedes this operation. Russ
Jul 10, 2006 | Stencil cleaners. The potential to damage stencils by bending the metal of the fine pitch portion of stencils is a concern about spray cleaners.
Apr 21, 2006 | is very low, here is an alternative: Remove the BGA with hot air. Clean the pads. Purchase a small BGA stencil and squeegee. (google/yahooo for them, I can't remember off the top of my head) Squeegee the paste onto the board. Use your pick and place to put the BGA at the correct location and reflow . You could also remove the BGA with hot air, clean the pads. Apply tack flux, place the BGA by hand and reflow. Leaded BGAs will self-center. You cannot rely on no-lead to self center, though.
Mar 8, 2006 | adjusted Printer and reflow to supplier recommendations but am still getting mixed results. To get the boards to pass all tests it is essential that this fillet is achieved. I am usin no-clean paste with a 6thou stencil. Any ideas please feel free to let me know.(i have searched thry some threads
Mar 2, 2006 | I recently finished analysis of no-clean fluxes and Ionic contamination and cleaning processes. The results were eye opening. Summary: If you clean a no-clean you better do a good job. Many no-cleans produce a "waxy binder" to encapsulate the troublesome ions. Identical process as in the old RMA days. No difference. If you didn't clean an RMA then why clean a no-clean now? I would: Use BELCORE certified, halogen free materials, verify your thermal process for no-cleans (good profile), control you flux application process (only apply what you need) and not ROSE test for ionics.
Feb 13, 2006 | Clean the No-Clean Cleaning no-clean is the pitts. If cleaning required migrate to water soluble. Can IPC help here? No cleans only need to be removed per IPC if the joint inspection is inhibited...and in general if form-fit-funciton is not achievable. But then there is always that annoying customer who insists it be removed merely on the basis of cosmetics (even though the product is burried in a chassis, kept in a dimly lit dungeon in an Artic region) I will assume this is a customer driven specification. In which I will recommend re-evaluating no-clean solder pastes in addition to new cleaning chemistries
Feb 13, 2006 | Clean the No-Clean Here are some cleaning chemistry companies that have products to clean no-clean flux residues: www.zestron.com www.kyzen.com www.petroferm.com They all have engineers on staff that can assist with setting up a custom cleaning process.
Feb 2, 2006 | Sorry, I am jumping into this late - I'm a new user. Our company is looking to perform an evaluation for a new paste. We are looking at a 63/37 no clean - type 3 or 4. Our technology is currently at 0201s, .4mm pitch ICs & .5mm uBGAs. I have been coming across a lot of paste manufactures offering to come in to our facility and perform the evaluation with us. On one hand, I would appreciate the help, but on the other, I feel that it would be a bias result. Some of our important factors for a paste include: stencil life, wetting, ICT compatible, & use of nitrogen. Our current defects
Dec 8, 2005 | Questions are: * Is the stencil design proper to provide the correct amount of solder paste? * Is the stencil design proper to provide for release of solder paste? * Is solder paste filling the stencil aperatures, prior to separation? * Are stencil aperatures open / not clogged with dried paste ? * After separtion, is the paste on the board or the stencil?
Sep 11, 2005 | I agree with prior postings, but there is no perfect yes/no answers, right (left)...? Only good questions to be answered. I think it is overkill to have an extra stencil, why do you need it? (That is if you have a proper stencil cleaning equipment). Think about the % of lead (it is not only lead
Sep 2, 2005 | we can not afford to set one line for Lead-free process and remain idle depending on production forecast. I'm planning to purchase a separate set of Squeege for printer only for Lead-Free process & separate dedicated stencil for Lead-free models use only. Would this be enough? Do we need to make a major clean-up for printer & reflow before we run Lead-free process? Please advice? Regards, Pyramus
Jul 14, 2005 | Lead Free Stencil Design Stencil thickness is related to PCB design and is not related to paste type. If you release with a 8 mil stencil then use an 8 mil stencil. Of course there are pastes that release bteer than other and what not but use area and aspect ratios to determine stencil thickness.
Jul 14, 2005 | Possible to water wash no-clean solder 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
Jul 14, 2005 | Problems with frameless stencils on MPM?? We use the Frame with the frameless stencils, but they seem to not be as tight as the stainless steel frame stencils
Jun 13, 2005 | Paramjeet Singh Gill So, you underfil before cleaning. Interesting. * What is it about your underfill that prevents the OA flux from attacking the FC solder balls? * Who is the underfill fabricator and product? Getting back to your solder balling issue: * An earlier poster commented will.] * Poorly developed reflow recipe is another cause. How well does your recipe match with your supplier's recommendations? * Another driver is the amount of solder paste. What are the sizes of your stencil and the pads on the board?
Mar 31, 2005 | I agree with chuck, but would like to add. 2D is a great option and helps to keep your printing process in check, it will measure the x & y coverage on the pad. It will help you determin when your stencil aps become clogged or when the bottom of your stencil needs to be cleaned.... It will also
Mar 2, 2005 | / pad geometry / package warpage / paste volume / nature of IO (ground pin, power pin)/ reflow profile (soak time, dwell time)/ solder paste condition / stencil aperture clogging, cleaning and so on. Insist to your customers that you need to look into his process and my experience is the problems can
Sep 14, 2004 | Labeling of SMT solder stencils Perhaps your stencil supplier could laser mark the number on the stencil. This only helps from here on. How about engraving the numbers on the stencils you already have? Engravers are pretty inexpensive and shouldn't damage the stencils.
Jun 16, 2004 | Storing non-framed stencils We have a cabinet that holds all of our stencils. It is a homemade cabinet made to fit stencils with about 12 drawers and each drawer holds about 10 stencils. Each drawer is labeled with the stencil# for each stencil. When a new stencil comes in we just make a new label.
Jun 12, 2004 | hue to LF paste? This way I inpect our 6 lines I can just look at the stencil and KNOW what material is on there? Or add a material that flouresces in UV to no-clean lead free solder paste? Damnit! Sorry to vent guys, but I just wanted to emphasize that no matter how good your processes
Jun 1, 2004 | Is Aqueous Cleaning Recommended for BGA boards? We have been populating lot of BGA boards and for all these boards we have been using No clean solderpaste. We are under the impression that aqueous cleaning is not recommended for BGA boards as the residue cannot be cleaned properly. However we are facing lot of process issues on these boards and want to try aqueous cleaning paste instead of no clean. We have a conventional aqueous cleaning machine from H20 products. In this machine ionized water is sprayed from top and bottom of the board moving on a conveyor. Please clarify whether this cleaning would be sufficient to clean the residue
Apr 14, 2004 | Hi All, Just have a share with you guy. We are using T4 solder paste and also E-Stencil. We ahd try out Alpha, Kester, AIM and Qualitek. The result show Alpha had a very very heavy stack flux and can't get it clean off even by chemical wash, Kester is a good paste but service is Poor
Mar 4, 2004 | There is a japanese company that makes a ultrasonic hand-held stencil cleaner. I demo'd it for a day and it was fantastic! It even cleaned epoxy stencils. Can't recall the price...but it should be much much less than the smart sonic and other "machines". Plus it can use water, alcohol, zestron
May 21, 2003 | Zestron Has PDF down loads available on the Product listed above. Also, Contact Jeff Stong or Gu
Apr 7, 2003 | I have just started an assembly which uses a 16 mil pitch QFP. We ran on Saturday, using a type 3 solder paste. (working Sat's really sucks) We really struggled with paste release after the stencil sat for 15 minutes without printing. Apertures clogged up and were difficult to clean. We tried 3
Feb 27, 2003 | ! with these we processed uBGAs (and everything else)quite frequently with OA fluxes and daily testing showed extremely clean boards (0.0 ug/NaCl per sq.in.) I should note that I did not eval any of the other units that you are pondering. I have used equipment from these manufacturers before exept TREK. In my opinion I would rate them from best to worst Electrovert Austin America - had stencil cleaners etc.. worked fine A couple of empty spaces here, in my opinion Austin and electrovert are far ahead of T.D. Technical Devices - Had a wave solder machine. Pretty poor engineering and design on the units I
Sep 25, 2002 | UltraSonic cleaning machine Michael- Please when concidering you U-sonic machine, keep in mind possible chemistries Petroferm, Kyzen, Aqueous technologies, and Zestron products. All are good products and all need to be evaluated with your stencils. Depending on your component type and Solderpaste type will determine
Aug 27, 2002 | We use an evaporator, so that we only have a sludge of flux residue and solder metal to dispose of via the hazmat handling service. We also route stencil washer waste water into it. We use a 30 gallon drum and have it hauled off maybe twice a year, about half full. I'm afraid if we wait any long they work. I would surmise that you'd either clean the filters and call your local hazmat disposal service to haul off the dregs, or just have them pick up the disposable filters. Maybe someone here is using one of those systems and can fill you in...?
Pages: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196