stencil cleaning

"stencil cleaning" search results in the Electronics Forums

9777 result s found for "stencil cleaning" in the Electronics Forums

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Solder Ball Attach

Sep 24, 2018 | We are attaching 0.50mm diameter SAC 305 solder balls onto 0.38 diameter Au plated pins placed at a 0.80mm pitch (pins are pressed into a plastic insulator). A tacky flux is then stenciled onto the pins using a stencil with.a 0.38mm diameter aperture and 0.13mm thick SS.There can be up to 400 balls

Speedline Accuflex issue

Jul 16, 2016 | the desired result. The 'Offsets' calibration stencil consists of a 49X49 array of apertures (51X51 if you have a UP1500 cal stencil) that you will print on to a 20X20 copper clad PCB, which will then be lowered to Vision Height. The cal routine will look at the aperture and corresponding deposit

LGA Solder Balls

Mar 8, 2016 | ="mailto:soak@150c">soak@150c. 200-287secs=spike@220c. 4. This is a recent phenomenon. Approximately 3000 boards have been built with no issues. 5. Oven is calibrated. 6. No visible printing issues. 7. 5mil thick stencil. 8. We were underwiping stencil every other

Leaded Water Soluble recommendation needed

May 30, 2013 | life of 2 weeks at room temperature, as do a lot of other pastes. Given this, I wouldn't expect significant drying in 15 minute cycle times. A couple of things to check: 1. The operating environment like for the stencil printing? Temp/Humidity/air flow. 2. Temperature of the paste at the beginning of operations (warmed up to room temp per vendor recommendations?). 3. Aperture design of stencil. 4. Age/storage conditions of the solder paste. 5. Appropriate sphere size for aperture design/application. It might be worth getting the paste rep/application engineers involved in helping you diagnose

Stencil-PCB Alignment Mehods - Printing process

Dec 16, 2011 | Stencil-PCB Alignment Mehods - Printing process , the camera moves out of the way and the board and or stencil is moved to print height. After that, the Squeegee does it's thing. About the Alignment features, They are typically round dots in opposite corners of the PCB. We call them fiducials or fids for short. There are often fids close to fine pitch pads

estimate solder thickness

Jun 7, 2011 | solder under the iLCC contacts will raise the image sensor up slightly. Assuming I have a 0.005" thick stencil (which I do), how thick is the bottom of the chip likely to be once the solderpaste is melted and hardens in the reflow oven? Will it be 0.005" or something less or more? The openings in the soldermask are just a hair larger than the openings in the solderpaste stencil (about 0.001" ~ 0.002" smaller). I'm guessing 0.004". But that's a guess. Does anyone know? Thanks

Researching placement machines - where do I start?!

Nov 22, 2009 | built a controller that can run four at the same time, but two can actually keep up with the output of the p&p. I will likely get a conveyor oven at some point, but my present location does not have adequate electrical service. For stenciling, I'm using prototype style stencils, several of which

Paste Expiration

Feb 20, 2008 | it but you do what you can with limited resources. At my last job paste handling was tightly, we use up what we're able to. We don't buy jars, just the 600ml cartridges. At the end of the day we transfer what's left on the stencil to a jar (IF that paste came out of a tube) and cram the plug down on it to slow down the inevitable. If the paste on the stencil had been dispensed from a jar, we toss it. The cartridge goes into the fridge and gets used up first when we run again, then we dip into the jar to see how it prints. If it won't, we toss it. Anything from 25 mil pitch or tighter

Solder Paste Inspection Systems

Dec 28, 2007 | fail, and it was not often that this would happen, it was almost always due to a machine issue. Particularly it was often due to a clamping issue with those razor sharp Dek edge clamps getting dinged. The PCB did not sit flat against the stencil when the edge clamps had dings in them. There were a an under stencil wipe when 2D inspection failures occur. With metal squeegee blades and automatic printers, height of paste is usually met if length and width of the printed solder brick is in spec.

Small batch Manufacturing

Dec 17, 2007 | his own business, 200-300 for a stencil might be alot...again, I don't know his full situation. Anyway, I don't have personal experience with this, but look into table-top solder paste dispensing. If your designs are easy-peasy (nothing smaller than .080 x .050 chip components, or if your lead -to-lead spacing is 0.050" or greater on your active devices), table-top solder paste dispensing may be the way to go. OTOH, if the designs in your company are stable, then investing in stencils and a manual or automated printer may be the way to go. Here ya go.

Small batch Manufacturing

Dec 17, 2007 | You can spend a couple grand on a manual screen printer, or do what I did back in the day: place the board on the work bench and lay the stencil on the board. If you can hold it steady enough you can use a putty knife to apply your paste. For the stencils, if you are doing them by hand or manual

via under a smd pad ?

Nov 15, 2007 | I do think that the designer goofed, and used too large vias. I believe he only used on size via on the entire board, regardless of whether it was in a pad, or out on the board. I have seen vias in pad work, though. From a manufacturing standpoint, we used a thicker stencil to apply more paste , knowing that the paste was going to wick into the via. What may be needed, in some instances, is a step-down stencil, so that a thicker layer of paste is placed on the pads with the vias, but a thinner layer of paste can be laid down on the fine-pitch devices. At a rough guess, I wouldn't want to see a

QFN soldering

Nov 10, 2007 | reduction of 20 % (80 % solder paste). Then you still be able to solder the terminals around. We SMT-mount & reflow soldering various QFN packages onto our customers pcb:s without any problem. We also make our own stencil apertures always with the very same stencil thickness = 127 microns = 0.13mm (approx

Mydata A12 tool tip damage

Jul 20, 2007 | plug up the bottom of the ELMO unit causing it to overheat and when that happens the power resistor in the bottom of the ELMO will blow up inside its heat sink (learned this the hard way). We clean the card cages fans and cage itself annually now. This entails removing every card, Elmo power supply and blowing the cage out, vacuuming the foam under the cage inside the machine, cleaning the circulation fans under the cage housing and the main intake fans in the rear of the machine. Cooling of these machines is very important for repeatability and consistant operation without failure. We have halfed our

Reflow Profile Design

Jun 15, 2007 | clean break, and often there is clean hold pads under the part after it's broken off, so the solder does not look like its adhering to the pads correctly, even though the product tests ok. We have run our profile specification window 6 degrees hotter in the reflow part of the profile, above what

Head in Pillow effect BGA

Apr 13, 2007 | BGA suppliers can do in their process to reduce it (mold material, mold preheat, clamp pressure, cure time, interposer copper design, etc...). We've also had instances where it was our fault. Either the stencil apertures were too small or we'd some how let print get out of control and there was insufficient solder to help make up the gap due to warpage. In those cases we either purchased new stencils with proper apertures to assure enough paste or figured out what our manufacturing site had let get out of hand in the print process. I've also wondered if a paste that exhibited superior hot slump

Reduction of solder paste usage

Mar 14, 2007 | We use cartridges, that way nobody can mix back in paste off the stencil and no air can get in period. Any paste that is still good to use when removed from a stencil at the end of a job is put into a small pink zip-lock baggy with the date written on it. Most EMS have these bags around for kitting

Indium Solder Hermetic Seal Voiding

Jan 10, 2007 | to use > Rosin flux for cleaning purposes, but could go to > an acid flux that can be easilly cleaned. Any > suggestions for fluxes or profiles when making a > hermetic seal of this type? I once used 60/40 In/Pb NC solder paste for soldering to gold bumped flip chips. Used the In

Look what I found - is this stencil printer a known product?

Oct 23, 2006 | Look what I found - is this stencil printer a known product? > "Surface Mount Techniques has approximately 98 > percent of the world market share of large Panel > Stencil Printers". > > It sounds a little bit > strange to me, especially since I work for one of > the companys listed in their advertisement and it > is definitely


Aug 15, 2006 | Alpha UP78 was a modern solder paste. Check with your supplier for recommendations. You're are cleaning some flux residue with the IPA and reducing the leakage current. We're not wild about using IPA. Problems with IPA are: * IPA / material being 'cleaned' combination still needs to be removed

Poor soldering on fine pitch?

Jun 8, 2006 | We are a small company, reletivly new to doing our own SMT (1 year) and we are having an issue, I think. We manufacture many board with no problems, but we have one that constently defeats us. This particular PCB has ENIG finish, and we have had the same problem with both tin/lead (no-clean , and SAC305 (no-clean and aqueous). The problem is with QFP100 & TSSOP48 packages. They just don't seem to want to solder their leads down correctly. We have leads that seem to be soldered, but with a little poking come right off the pads. SOICs, 0805s, 1206s, crystals all seem fine. Now I have a couple

solder compatibility

May 9, 2006 | C/O general manager Dear Sir This is Shenzhen comofaje,Ltd from China mainland We are the Associator of Hi-tech industry Association, so I think we can become your supplier in China. Now we have Four series products:1 SMT stencil wiping roll/wiper special for FUJI MPM DEK MINAMI YAMAHA SANYO and so on ,non woven wiper 2,kinds of SMT Splice tape, Stencil Machine Accessories,���� Joint Tape,��Kapton tapes, SMT Splice Clips 3 anti-static mat. 4 SMT/SMD Cutting tool and splicing tool If any of them meet your interesting please send message to

Electronics Manufacturing in Morocco

May 9, 2006 | This is Shenzhen comofaje,Ltd from China mainland We are the Associator of Hi-tech industry Association, so I think we can become your supplier in China. Now we have Four series products:1 SMT stencil wiping roll/wiper special for FUJI MPM DEK MINAMI YAMAHA SANYO and so on ,non woven wiper 2,kinds of SMT Splice tape, Stencil Machine Accessories,���� Joint Tape,��Kapton tapes, SMT Splice Clips 3 anti-static mat. 4 SMT/SMD Cutting tool and splicing tool If any of them meet your interesting please send message to

Masking of PWBs prior to conformal coat

Apr 21, 2006 | if the coating is sprayed. In my experience, when dipping a board for coating, the only way to go is liquid mask. If the tape is not completely sealed to the PCB, then capillary action will pull the coating under the tape. It happens instantly. Also, in some cases, a stencil works well. We recently had an order for a small # of boards that required a high voltage area to be coated. I cut out a quick stencil out of cardboard and sprayed the area. Worked perfectly and cost virtually nothing. There is a variety of factors to determine what's best. Unfortunately, part of that involves doing it the wrong

Fighting solder beads

Mar 21, 2006 | . In worst case paste brick has 25-50um shift. PLL has leads from bottom side only. Hence, during placement paste can easily get to PCB mask forming bead during reflow (I suppose that paste can not get back to pad due to segregation). 2. Stencil design. As mentioned above, aperture has next geometry: 482um x 229um (electroformed nickel stencil, 125um). Area ratio = LxW/2x(L+W)xT = 482x229/2x(482+229)x125 = 0.62 Aspect ratio = W/T = 229/125 = 1.83 If aspect ratio and area ratio are not violated paste brick must have shape close to �ideal� one. Am I right? 3. Reflow recipe. Beads are localized near

cleaning PCB's

Jan 10, 2006 | cleaning PCB's -based defluxing systems utilize environmentally safe and highly effective chemistries. An aqueous-base system is capable of removing all flux types including water soluble, rosin, and no-clean (both 63/37 and pb-free). There are several manufacturers to choose from including: Aqueous Technologies (that�s us

gold wire bonding

Dec 29, 2005 | well below 4 grams with 0.0033 inch diameter wire. I also do not plasma clean at all. Plasma cleaning may give you that extra advantage that I do not have. With 0.0033 inch diameter wire, I get at least 12 gram pull strengths and average about 14 gram pull strengths. My stitches are security bonded

checking QFP's for opens

Sep 13, 2005 | that you have to control....program selection, stencil washing, paste control, bare board quality, etc., then getting the resources to control it all. Edited to add that if you have problems and decide you need to inspect everything, a microscope is a much safer method. If you feel like you must poke ....with an OA flux. A new layout, a couple iterations of stencil design, and a new printer later, we stopped drag soldering. I won't tell you what happened when we had washer problems.

UP1500 Frame Sizes?

May 3, 2005 | I 100% agree, KEN is absolutely right. If your machine is equipped with a stencil cleaner, and it is the original SMTech USC with the full length bar, you are in trouble already. If your software is of an earlier vintage, upgrade ASAP. Anything less than 6.32 will have issues, if your in the 7.xx at many, many sites in the past. Your 1/4-20 screws will strip or gall up. If you have a older MPM style adaptor that is not hogged out, it will weigh a ton, and will eventually be dropped. The machine is designed for full size stencils, The original universal adaptor proves this, it was almost

dendritic growth

Dec 14, 2004 | or random, same for the crystal growth. Do you see dendritic growth without the crystals or are the crystals always present on locations with dendritic growth. How did you clean the boards with water or solvent based cleaning. Analyzing the sequence of tests you did (and not having answers to previous

Coating adhesion problems

Sep 21, 2004 | > Conformal coat a bare board to determine if there > is there is enough surface free energy from your > solder mask to prevent dewetting. Sorry for my ignorance, but what is "enough surface free energy"? How do I determine that? >* Bake a board > after cleaning with IPA with the conformal coating? > Going back to > your reason for IPA cleaning, if you are trying > to remove filings from your Rototrim, why do you > need to use IPA? Is the flux res sticky? Well, I'm not sure about it, I really beleive that process is there since the regular fluxes were used. I have

Lead Free ...

Aug 31, 2004 | Thanks Ken for your reply. Concerning OSP, there are a few negative points that I must considered for our application. I've read all the following points in an Entek document. Never test it. - If you have a miss print and you clean the PCB, the coating thickness on your pads change and the shelf sides. Shelf life is different on this PCB either. Here is a part of the article ... Production experience has shown that hold times of up to 24 hours are typical and SHOULD NOT be of a concern (NOTE: This is not apply to PWBs that have been wiped-down or cleaned with solvent. For us, after SMT

Electromigration Testing

Aug 18, 2004 | Davef, Sorry for the late response. I was trying to gather more info. The group with low ionic contamination levels came from one of our other facilities. We want to outsource more of our product due to increasing demand. Both groups use the same no clean flux and manufacturer, Aim. The only differences between the two groups that I know so far are: Low Ionic Group B Ultrasonic Spray Flux Solder Paste (Sn62) Enclosed Area (clean room type) Higher Ionic Levels - Group A Solder Paste (Sn63) Reg. Spray Fluxer Lowered the flux amount and improved ionic levels to 16 - 17 ug/in^2 although affected

Warming up solder paste at start of days production

Jul 27, 2004 | are that concerned about it, then order your paste in cartridges and buy empty jars. When the operator runs low on the stencil, have them dispense paste from the tube. When you use this method you are always ensuring that "fresh" paste is being added daily. At the end of the day scoop it off the stencil and put

Warming up solder paste at start of days production

Jul 26, 2004 | we tried to do vapor phase reflow on the kitchen hot-plate with a pasta cooker. It worked, but we were so excited we kept taking the lid of the pot, and the vapor got out and condensed everywhere. It's really hard to clean up because it does not evaporate well at room temperature. The fluid coated in. So we really messed up the kitchen where clients normally prepare their food. It was a really trendy slate kitchen etc. So we desperately were trying to clean up before anyone came and noticed. But it worked really well, and we reflowed two new prototypes the morning we had to fly

Can anyone recommend a reflow profile for already flowed solder?

Apr 21, 2004 | Simple process - we use similar Kester solder brands of "no clean" low residue solder wick to clean our pads, then brush with isopropyl, and apply Kesters brand of tacky flux under a Leica 6x microscope. We do this on 7x7mm and 9x9mm packages. This works well with our failures from test, where we

contamination on copper

Apr 16, 2004 | Your copper corrosion is not good. It indicates that you have not done a good job in cleaning. [We assume this is a medium green color, not unlike the color of the solder mask on your board, that is almost like a translucent lacquer; rather than the opaque, light green color of an achitectural -on flux residue, which makes it difficult to clean properly. [Ah, if only buyers would realize the problems they create in "saving" a penny on the cost of a part.]

screen printer from MPM

Feb 6, 2004 | ) but should do 16mil(0.4mm)with a good stencil and board design. Alignment repeatability: +/-0.004" at 6 Sigma for the MicroFlex and +/-0.0005" at 6 Sigma for the SPM. Also, SPM has a greater snap-off range adjustment as well, 0 - 0.3" vs. 0 - 0.1" for the MF. The SPM and MicroFlex use the same camera holders to the paper to loosen paste from the stencil apertures. Then you follow with a dry wipe. You can set it for wet then dry or dry wipe only. Vision alignment is a good option too. Good luck.


Jan 13, 2004 | I believe that solder paste will need to be applied to this part. I have re-balled these in the past in a low volume situation and here is what I did and there appears to be no adverse effects to the component. Get a stencil (I use 8 mil for .032" high temp balls) for this part from someone like minimicro stencil, They may also provide masks for applying solder balls. You may need to fab some sort of BGA holder for the print operation. Print the pads on the BGA and then reflow at the minimum temp to just get it melted, about 190 C for 63/37 alloy paste. Then you can use a mask as noted previous

low volume /semi-automatic solutions

Jun 18, 2003 | will have extra costs..i.e. Stencil costs, stencil wipes, Paste costs, Nozzles, feeders, installation costs so keep in mind that once you go this way you will always have cost. I like going this way as you can monitor quality better and react faster to issues. In addition you may want to take some basic

TSOP40 Lead pitch 0.50mm recommended aperture sizes?

Mar 7, 2003 | Q1: What are the recommended stencil apertures for a TSOP40. Lead pitch 0.48mm & lead width 0.21mm. A1: We've talked about this previously here on SMTnet, for instance check the fine SMTnet Archives: http://www

ESD Safe Flooring Systems

Feb 10, 2003 | Hi I am in favor of the best money can buy tiles, and everything including an ESD officier and training for everyone. Long term less money is spent and ESD protection is kept high continually. Boy do I have stories like the cleaning guys who put on non conductive wax on a beautiful floor, and, and used by some company that used chemicals. What the business was escapes me right now. Even though the floor was cleaned really well before the conductive epoxy was put down the concrete, which is porous, continually would let those chemicals back on up and you would have ESD breaks. So what ever you

Intrusive Reflow

Nov 20, 2002 | Hello, need help on intrusive reflow process, thanks in advance to the experts and general info sharing :) need some help to obtain answers, to following questions: 1) PCB is FR4, 1.6mm thick, 4 layers, what stencil thickness (stencil design guidelines?) is optimal to get sufficient solder

Air bubbles in solder joints

Oct 30, 2002 | suggets that the cause of the problem is in the pre heat stage of the reflow process, where the flux has not had enough time to vapourise and clean the surface for soldering??!!! This does not sit well with me as we run another suppliers boards, exactly the same board design, and we expereince is not being released out of the solder paste to clean the PCB finish.( whichh I think is a load of crap) Any assisitance or guidelines in relation to this problem would be very much appreciated.

Vent Residue Cleaning

Aug 14, 2002 | Vent Residue Cleaning the joints of the vent tubing wrapped with a metallized version of duct tape. That stopped the constant drips. Secondly, I had a "P" trap installed so that the condensed flux residues would pool in a trap filter. That area could be pulled/cleaned/replaced periodically. A good HVAC contractor can evaluate you

Water Residue Stains - how to remove?

Dec 19, 2001 | the pallet before oven-bake drying process. Now the side facing down in contact to the FR4 pallet, is "spotty" with water-stain marks. As this affected side is the contact pads for the end-product "reader" unit, my customer says the water stains are not healthy, and require us to clean up the stains... we already tried prozone/IPA, and this only "cleans" the pads temporary, after the chemicals "dry-up" the pads have darker-yellowish water-stains again... I think the flex-PCB pads are either gold/copper in primary content, and my thinking is if its predominent copper, then the water-stains are stuck

Smurf Coats

Dec 10, 2001 | when they get scrufty. * One being cleaned. * One cleaned. We are very unhappy with the cost of coats ~$150 per employee. We recognize there is a balance between trying to "save" too much money when buying coats [You get "plastic bags" that get too hot for the people wearing the coats.] and getting a

Non-wettig on chip cap.

Dec 6, 2001 | secs, time to 183 Deg C ~ 5 minutes, peak = min 215 � max 220 deg C. b) Solder paste � I had tried 3 types 1) Delta 738S2 Water soluble 2) Delta 670S1 No-Clean 3) Indium SMQ-92 No-Clean I would appreciate if any of you guys can help me with suggestion or what should I do ? Thanks very much

Solder balls on Cleaned process

Oct 18, 2001 | Solder balls on Cleaned process , selling your washer for BIG bucks, and taking everyone to lunch with the proceeds of the washer sale. * New flux supplier. Recently, a sales type pitched us on a washable flux that reported doesn�t have to be cleaned between reflow cycles.

Solder balls on Cleaned process

Oct 17, 2001 | Solder balls on Cleaned process semi-cured concrete and entombed the solder balls loitering around, while awaiting further processing. * Second reflow [of the primary side] fully cured the flux residue from the first reflow. * Aqueous wash after the second reflow did a wonderful job of cleaning the residue and solder balls from

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