Order by: Relevancy | Date
Aug 21, 2019 | CCGA - Stencil design and Reflow Profiling And what is the solder paste selection recommendation for the same. 1. Water soluble ( organic based flux solder based ) 2. No clean ( rosin or resin based solder paste ) customer is suggesting water soluble chemistry , which is having lot hot and cold slump issues.
Aug 17, 2018 | stencil, but in that case you already have at least 2 panels which are printed and have to be scrapped(assuming you dont clean them). If you verify the stencil before that, you wont have that scrap. Stencil life has that information on every panel (pressure, speed etc), but not so much for the stencil information. Another company that I saw had more information stored from the stencil. Its all depending on customer-company relationship. Another example: of course the SPI will catch that you have the wrong
Jun 14, 2017 | Evtimov, I am curious...why do you say definitely use solvent ? We have never used it and never h
Mar 7, 2016 | We've had our My500 for about four months now, and couldn't be happier. We are a super-high-mix, super-low-volume shop, and the flexibility provided by the 500 over stencils is stunning. So, you buy 5-10 stencils a week? That's 260-520 stencils a year. At an average of $200/stencil, that's $52 ,000-$104,000/year. And, if you decide after receiving the stencil that there are issues that need to be resolved, you're into buying a new stencil for that project. At a cost of $200k, it looks like your ROI on stencil cost alone is 2-4 years. Then there's the paste cost. How much do you pay, on average , for 500g of paste? Around $100? How many times per year? The cartridge cost for the My500 is $15/100g. And, that 100g cartridge is lasting us, on average, about a month. There is no waste, no throwing away dried up paste that's been sitting on a stencil all day. No worrying about work time
Dec 12, 2014 | there are several ways: 1. Manual method- Remove the part using hot air gun, clean the pads, make a small stencil to re-ball the BGA and it is ready for placement. 2. Improved method - Use equipment dedicated for BGA rework 3. No hassle method - Give it to a company that does rework.
Nov 3, 2014 | Looks like you did everything right. Clean and check carefully the stencil for damage close to the part you are having problem with. If not both of your squeegees should be damaged on the same spot.
Mar 13, 2014 | stepped stencils Why don't you try to make your step on the squeegee side? that way you shouldn't have any issues with cleaning.
Feb 5, 2013 | Stencil Cleaning About a year and a half ago my company purchased an ultrasonic, automatic stencil cleaner that we,(I), am unhappy with. Without "naming names", I can say that this particular machine has some fabrication issues that prevent it from operating as intended. We've worked with the supplier, but I just feel it may be time to go in another direction. After doing some digging through the fine archives of SMTnet, I've seen some conversations regarding automatic and semi-automatic cleaners, as well as the pros and cons of ultrasonic cleaning. Can any of you upstanding young gentlemen, and ladies
Jan 8, 2013 | Stencil and Misprinted Board Cleaning Handbook
May 11, 2012 | Underscreen cleaning cycles You may also look into a product called Nano Protek. This is an application that helps reduce your cycles and increase productivity. In some cases beter paste deposition has been recorded. Contact your stencil vendor or I can give you information.
Jul 21, 2011 | I cleaned the stencil with IPA 99% before applying the Rain-X. Apply Rain-X as per instruction.
Nov 12, 2010 | I would also be concerned about spreading solder paste on the walls/floor/equipment downstream of th
Sep 1, 2010 | Dear Leeg, Generally the faster your print speed the more down pressure you need on the blade to roll the paste and wipe the stencil surface clean. Pastes with higher viscosity need more pressure at slow and high print speeds. Too much pressure causes the paste to bleed under the stencil and causes defects like bridging. Correct printer set up of speed and pressure is critical. Rule of thumb for speed and blade pressure is what ever the speed, the pressure has to be the minimum to wipe the stencil surface clean. Paste viscosity and rheology are the important factors determining print speed
May 14, 2010 | We used to use spray machines. We now have a PMR ultrasonic cleaner. Ultrasonic is the best in my op
Apr 5, 2010 | We have used different suppliers including direct from MpM and from a couple other sources who sell
Mar 30, 2010 | It happens on the middle of the stecil cleaning. The camera and the cleaner will stay under stencil in half way back. Then machine asking the initate the motors. If to press initate then the pcb stopper will hit the rails. Usually we move camera and cleaner manually back to home position
Dec 7, 2009 | Have you considered outsourcing the rework of the BGA? Besides the rework system, you will need: solder paste, stencils, cleaning method, X-ray, and the biggest part experience...
Nov 3, 2009 | Search the finee SMTnet Archives for previous posts on the topic. Here's a clip from on of those posts that may get you started. [snip] * Stencil material: metal or plastic, no difference in print, metal is easier to clean, no static problem, available * Stencil thickness: Chips 0.006", SOIC 0 speed: 1 to 2" per sec * Squeegee pressure: 0.2 to 0.3 kg/cm ... enough to clean wipe the stencil * Separation speed: Slow ... 0.1 to 0.5 mm/sec over 3mm separation distance * Print sequence: print print
Oct 9, 2009 | Here's what is on that post referred to, not sure what you need more than ... "* Stencil material: metal or plastic, no difference in print, metal is easier to clean, no static problem, available * Stencil thickness: Chips 0.006", SOIC 0.010" [print height equals 1/3 thickness] * For 0603 .2 to 0.3 kg/cm ... enough to clean wipe the stencil * Separation speed: Slow ... 0.1 to 0.5 mm/sec over 3mm separation distance * Print sequence: print print" ... further, we guess that you're printing at 1-2 inches per second.
Sep 21, 2009 | What babies!!!! Sure, give it a try. * Stencil material: metal or plastic, no difference in print, metal is easier to clean, no static problem, available * Stencil thickness: Chips 0.006", SOIC 0.010" [print height equals 1/3 thickness] * For 0603, aperture size was an oblong shape , 0.030" long x 0.015" wide. A minimum of 0.010" gap between the aperture and pad, both sides. * Snapoff: to increase dot height, upto 0.040" can be used * Squeegee material: metal on metal, polycarbonate on plastic * Print speed: 1 to 2" per sec * Squeegee pressure: 0.2 to 0.3 kg/cm ... enough to clean wipe the stencil * Separation speed: Slow ... 0.1 to 0.5 mm/sec over 3mm separation distance * Print sequence: print print
Sep 23, 2008 | For additional information, download IPC-7526 - Stencil and Misprinted Board Cleaning Handbook http://www.ipc.org/html/IPC-7526.pdf
Aug 21, 2008 | I'd like to hear from anyone using the PumpPrint stencils to dispense/print solder paste. Are you using ProFlow or just squeegee blades? How often do you have to clean?
Jul 31, 2008 | We use Axarel 2200 as recomended by Vitronics Soltec, which is the same as we use on our MPM printes for under stencil cleaning. It is non-ozone depleating and has a high flash point. For insurance purposes we banned IPA from the shop floor some time ago.
Apr 4, 2008 | ZOINKS!! Yet another thread on PCB support. These discussions get *almost* as heated as - dare I even mention - stencil cleaning. Let the fireworks begin!
Jan 30, 2008 | What is commonly done in the industry regarding when to clean the stencil, squeegees and replenish the solder paste? Is it every 4 hours, 8 hours or something else?
Sep 22, 2006 | Be careful of inverted homeplates if you hand clean your stencils. The "spikes" can easily catch on the wipe being used and bend up. Not to mention the nice slashing it does on your hand that immediately some how fills with solder paste.
Jul 26, 2006 | Samir, why do you bring back such idiotic rubbish between two gentlemen that just happen to fall into their presidency? It is not rellavant to the questions at hand. I agree that ultra sonics can clean better but do take longer IMO. As for stencil damage, I do not see how a sprayer can damage a Stencil cleaners. stencil. I have actually stood on some of my stencils and they do not break. Granted I only eat 3 bananas a day since I am fasting. Still you would need a a very high pressure to dmage a stencil. Sorry Davef, I do not mean any dissagreement. You are "da man" around here and are still top dog in ALL
Jul 24, 2006 | simple answer. In my experience, ultrasonics do a much better job of cleaning the stencils than high-pressure jets. Ultrasonics impart far more energy into the contamination through the solvent than any high-pressure spray could generate. Some tests have found collapsing cavitation can generate up to 10 companies using modern, digitially controlled, sweeping ultrasonics find they can do so without damage to their boards or stencils. Of course, get some expert assistance when specifying a cleaning machine, because too much power can break anything apart, with or without the harmonic build-ups. More of lightning, and a pretty spectacular fire would result. So get an ultrasonic tank and use a nonflammable solvent, like Micro Care's BGA Stencil Cleaner, to do the cleaning. The attached article, by a fellow named Kenyon, pretty well explains the process. Best regards, Mike Jones, Vice President Micro
Jun 16, 2006 | First, isn't paper a nonwoven? Maybe we start splitting hairs on whether paper is a 'fabric' or not
May 3, 2006 | Water Soluble vs. No Clean All good points by Pee Wee Herman; your solder balling may appear if you don't currently have stencil with reduced apertures or "homeplate" design. "Flux is solders' muscle."
Mar 30, 2006 | UP 2000 is a good printer. Spares are normal - blades, stencil/board light bulbs, the over head flourecent, get new conveyor belts. Take the cover off the tactile sensor and make sure it's clean also. Other than that it should be a work horse.
Nov 9, 2005 | Good day, So, only material supplier recommendation is the basis for solvent selection. Am I righ
Oct 22, 2005 | Proof Of Design has a number of free documents as operations procedures:
Sep 11, 2005 | I forgot to mentioned, that we produce both leaded and RoHS products in the same SMT-lines. The only thing we do; is a more trouhgfully cleaning of the stencil printing machine in beween product changeover of leaded/RoHS products.
Sep 11, 2005 | I forgot to mentioned, that we produce both leaded and RoHS products in the same SMT-lines. The only thing we do; is a more trouhgfully cleaning of the stencil printing machine in beween product changeover of leaded/RoHS products. Sincerly,
Jun 13, 2005 | Stencil Rolls The Standard prize for the cleaning rolls is about RM30(US 6.5 dollar).That's too expensive already.BEST REGARDS.
Jun 2, 2005 | Stencil Rolls I'm still buying my solder printer cleaning rolls from my manufacturer. Does anyone know of any after market brand that is as good in quality and atleast half the price. I am paying $80.00 a roll. Gary
Apr 28, 2005 | If what you are talking about is "assembly materials", then consider the following: - Solder paste - Wavesoldering fluxes - Bar (for filling wavesolder pots) - Underfill (for TCE-mismatched CSP's and flip-chip) - Cleaning fluids (for post-reflow boards and for stencils) - BGA balls and metal preforms - Solder wire and flux for rework There's a hundred varieties of solder paste, based on variations in: - Deposition method: Stencil / screen / dispense - Alloy type: Sn63, Sn62 etc... - Powder size/size distribution (size 2, 3, 4... per J-STD-006B) - Metal loading (usually 84-90%w/w) - Flux activity (OL1, RM0 etc.) - Post-reflow cleaning (no-clean, water-washable etc) I hope this helps.
Apr 25, 2005 | designed for parts cleaning (including stencils) and not post-reflow assemblies. Cleaning reflowed assemblies is generally more critical than degreasing parts or cleaning stencils. In the latter applications, there are few documented cleaning specifications that refer to ionic contamination. Although and other devices by the application of ultrasonic energy. Regardless of the accuracy of these concerns, the appearance of the concern may be enough to render ultrasonic technology unacceptable in post-reflow de-fluxing applications. Lack of automation and SPC: Most ultrasonic cleaning systems were ultrasonic technology is a very good cleaning method, the machines that utilize ultrasonic technology usually lack a complete wash + rinse + cleanliness test + dry process. Most ultrasonic cleaning systems do not provide adequate rinsing for circuit assemblies (rinsing is the most important process step
Mar 2, 2005 | Top 5 of No-clean Solder Paste I like Alpha Metals OM-5100. Very long stencil life with good results. Jerry
Mar 2, 2005 | Top 5 of No-clean Solder Paste Russ, are you using any reduction on your stencil aperatures? How much for what type of parts? We seem to have to many problems with resistor network aperatures clogging. How well does this paste release from small aperatures?
Dec 15, 2004 | small joints on the larger components like Tant D, coils, etc... So a step stencil may be required for the 4 mil depending upon application. We went back to the 5 mil stencil and increased cleaning frequency and never had any problems. This component was a BGA with eutectic solder balls so we were Stencil Thickness I have used both 4 and 5 mil stencils for 10 mil round apertures. We don't have volume measurement capability but we measure height and the 4 mil appeared to have more paste and better uniformity from a visual standpoint than the 5 mil. The unfortunate thing about the 4 mil is that it left very
Nov 22, 2004 | Hello Brent, I recommend that you read an article by Richard Clouthier, "SMT Stencil Cleaning: A Decision That Could Impact Production." It originally was published by EP&P. We keep a copy of it on our web site: http://www.smartsonic.com/article1.html Mr. Clouthier reviews the different chemistries and methods for cleaning SMT stencils. If you should have any questions, plase do not hesitate to contact me. Regards, Bill Schreiber Smart Sonic Corporation firstname.lastname@example.org Tel Stencil Cleaner Chemistries
Sep 30, 2004 | We have been screen printing adhesive for about 4 years. Works well but it does require my opertators to pay more attention to what they are doing than they would prefer. Keep your stencils really clean. Once that epoxy dries in an aperture, it is hard to remove.
Jun 21, 2004 | Dear Kanwaljit Singh, my opinion is following: 1)solderpaste type is ok - usual (alpha-metals has this problem inside the paste paste- holder problem) - what do the operator when production change -clean well the stencil holes!! no visible rest on the mask -directly loaded? when stencil change he or both. 3) sencil cleaning is fequent by you....ok try machine top leaning stencil(by Fuji GP64x series) when not possieble by hand at problematic aera and no cleaning material should be present after cleaning. is a question to try. whith this material is ok to try cleaning pcb IPA wet cleaningpaper of the pcb is beein started oxidation or fat (from operator hands) is persent on the board 2 way to solve:- operator use esd handshoose - behind you they take of....board newer protected - use cleaning direct the board------if possible use water based material wich regeerate oxidation or cleaning fat
Mar 8, 2004 | New Stencil Cleaning machine on the scene. Saw it at APEX 04, manufactured in West Viginia. http://www.pressureproducts.com/SPPC_Hm.htm
Mar 5, 2004 | We use a SAWA to clean our stencils and it performs quite well on solder paste but not so great with epoxy. Operators find the machine very easy to use and like mentioned before it takes up minimal space and has a lower intial and operating cost.
Aug 27, 2003 | are not saving any labor since you yourself stated that you would scrap all the excess solder off first. Not to mention potential problems with uncleaned apertures. Assuming you have a real stencil screen cleaning machine, it should have one of the several proven technologies to properly clean the stencil Bman Each area and process has a unique machine for a reason. Professional engineers at the various OEM�s have thought these things through and there are specific reasons why you don't wash stencils in a board washer, bake pizzas in your reflow oven, etc. In addition to Mike Konrad�s answer, you
Jan 3, 2003 | We have an Ekra E5 that uses what looks like standard auto valve stems to dispense the cleaning fluid. They leak.. Are they just standard schrader valves or are special to withstand the chemistry of stencil cleaner?
Dec 16, 2002 | Hi, We tried AIM no clean, and one other paste which I cannot remember the name offhand. We have been using Koki lately, and that's been the best. It seems to leave less residue behind in the stencil. Regards, Grant Petty Blackmagic Design
Dec 12, 2002 | off strength *Cleaning-Clean stencils and boards with current cleaners to determine efficacy. *Under stencil wipe-Inspect bottom of stencil after "X" prints and look for bleed-out. *Compatibility-Combine with current material sets to determine any interactions. *Ionic content-Measure for ionic
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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197