stencil cleaning

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

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How to reduce solder joint voids of LED without using vacuum reflow?

May 30, 2019 | Contributors in order of importance: 1. PCB design - if you have large thermal pads, a grid of via holes should be created. Components with low profile will not let the gas to escape from the joint. The only way is going down. 2. Reduce paste volume for better performance 3. Stencil design apertures. There are techniques for reducing voiding based on stencil apertures 4. Low voiding paste - this has never been the best help. You should have a descent paste from a leading manufacturer. 5. Reflow profile - soak profile creates more voiding in general. Less heat improves voiding. You burn

Step-up stencil: recommendation thickness

May 22, 2019 | Step-up stencil: recommendation thickness Thanks. It starts to make sense. There is a formula at the bottom of this page: http://www.circuitinsight.com/programs/50456.html It says: Stencil Thickness = 2.64mil + 0.0831 * pitch of component in mil

Aperture Adjustments and Etch Compensation on Arrays

Mar 28, 2019 | . The array files had etch compensation applied and the fabricated PCBs were over-etched slightly. The stencil aperture reduction was done from the adjusted array Gerber, so the stencil didn't gasket properly on the undersized pads. I would like to know if others have had similar problems and, if so, what

Have any paper or data talking about "BGA Stencil design guideline for avoid bridge"?

Sep 7, 2018 | Have any paper or data talking about "BGA Stencil design guideline for avoid bridge"? 't a reason to over print BGA pads except in the case of very small pads when you are trying to improve paste release. This leads into the stuff about stencil thickness, area ratio, etc. Maybe you can give us more detail about your problem, then we can tailor our responses to be more helpful to you.

SPI Programming

Jul 31, 2018 | A question for those that carry out SPI. How do you program? Do you take CAD data for the card which will provide a 1-1 pad outline or do you use the stencil data for the program is the actual tool used to determine the paste volume (Aperture reductions etc.). I’m interested as in my view deposited? Or would you use the stencil data to create the program which would have any changes and aperture reductions already applied therefore no ‘tweaking’. Perhaps the amounts are so small not to make a difference or can be lost in the tolerances applied? What are your opinions on this what do you

Void under QFN TI LMZ20502SILT

Jul 20, 2018 | This question is regarding stencil design: I am having voids under QFN TI P/N LMZ20502SILT. I have attached component pic. Signal pin is 18X16 mils. Center pads are 31 mil sq. Initially I had stencil done with one mil per side reduction on signal pad and ground pad both.(which is 87% solder

printed solder paste life time

Jan 7, 2018 | Your paste should specify a number of times it is OK for various things to happen. The two you might care about are the "Stencil Time"/"Working life", which is how long the paste can be out of the pot on your stencil while you print PCBs. The other is "Tack Time" which is how long the paste can

QFN84 Solder Printing Issue (QFN with Inner LGA Pad)

Dec 1, 2017 | Very interesting pictures. It shows paste height of 200um - which is at lest 6mil stencil deposit. That on the other hand posts another question. Can you measure the ground pad level in relation to the solder mask level with the SPI? I had assemblies in the past, where the the plating is way lower than the solder mask. If that is the case you might be getting a ton of paste in there, that has nowhere to go, because of the closed via holes. My suggestion is to measure that level and if you discover any difference in height, you should change the approach with the stencil. Make circles

Help understanding something about stencil orientation when printing

Nov 8, 2016 | Help understanding something about stencil orientation when printing the short way. A properly set up printing profile, a good quality well managed solder paste, good squeegees, a quality stencil with appropriate aperture design and what most people forget, proper clamping and board support for the PCB, will give you the results you need.

SMEMA Conveyor into Reflow Oven? How to handle end of line signal.

Nov 20, 2015 | To clarify- what I have is: 1. Manual stencil print process 2. Dynapace conveyor into GSM 3. Dynapace conveyor out of GSM into oven So what I need is a way to tell the conveyor into the placement machine to "go" when a board is loaded onto it after the manual stencil print, and a way to have

mpm up 3000 ultraflex

Jul 2, 2015 | Just to clarify, you are talking about the inner black box not driving down and not the pneumatic function that brings the tactile assembly closer to the stencil? Sometimes the pneumatic shafts get slightly bent and the assembly will not retract. This happens when the tactile assy. in jogged into the stencil frame. If the tactile motor is suspected then the small motor might have driven it's spline shaft to far upwards (full range is about 0.6")and jammed at the end of it's travel and then can't move. If the motor is weak it needs to be replaced. But sometimes if it can be worked loose the only

DQFN INSUFFICIENT SOLDER / HEAD ON PILLOW

Mar 6, 2015 | tried at least 5 different stencils designs and many reflow profiles (the current one has the PWI lower than 50%). If we follow the exact supplier stencil opening recomendation, situation gets worst. The problem was minimized when we have improved solder paste volume from inner row pads and reduced

BGA rework equipment - suggestions?

Aug 5, 2014 | A, but that is a bit crude for BGA's. It's Ok at removing them, depending on what is around the part. For some plastics etc, we cover them loosely in tin-foil, which seems to work OK. The stencils/masks are almost useless. We tried the ones you leave in place, but because they fill up the void under the BGA, it increases the risk of bridges. Plus, you need vast quantities of the various formats, as so many BGA's have different pad layouts. Most that we tried with the stencils failed afterwards, mainly due to bridges. Even dollops of flux didn't help. Lastly, do you have a URL for KPE

Solder climbs on the lead and touches the body of the component

May 12, 2014 | the upper ones but that helped just a little bit. Still the lead is hotter than the PCB(just as DaveF suggested) 2. I started to tape my aperture on the stencil and just after I reduced 75% I got a good result(as Hege suggested). It looks that paste reduction will fix it, so I will make calculations and will recut at least one stencil to see the repeatability of the process. Fixing the profile looks to be hard to get it there. DaveF I think that this pad is really absorbing a lot of heat as you said and I couldn't get it close to the temperature of the leads.

paste quality

Feb 13, 2014 | Have to agree with Sr Tech and Spoilt - you'd have to really mistreat your paste these days for it to be the root cause. However, try another paste to eliminate that; making sure you abide by the suppliers specs. Pad design, stencil design,(including thickness), reflow profile are the first areas to look at. If everything else is OK it's probably not the profile. Component termination material may be a cause. We also suspect solder mask contamination causing inferior wetting sometimes. We have an 1812 ferrite inductor that I home plate on the stencil for one assembly. We use this inductor

MPM Accuflex Squeegee Error

Feb 14, 2013 | I'm trying to get an '07 Accuflex into production and I seem to have a small problem. When trying to calibrate the zero pressure point on the squeegees I drive them down until they are touching the stencil and once they touch the stencil they run out of range before any pressure can be applied

Foil stencil storage rack

Feb 5, 2013 | Foil stencil storage rack We have a few Bliss racks. They were made for 29x29 frames but we use them for vectorgaurd and foil. DEK ships vectorgaurd stencils in a nice, thin cardboard box. We use these boxes for storing vectorgaurd + foils. You can store a handful of foils in these boxes (and 1 vectorgaurd of course

Paste Printing Problems - Toshiba SSM3K15CT(TPL3) FET CST3 package

Aug 13, 2012 | Maybe the area ratio between the sides of the stencil apertures and the aperture opening is too low for the spec of the paste ? So it will tend to stick in the apertures. ...only solution is thinner stencil or a paste that can release easily when area ratio is so small...maybe a size 5 paste

Auto stencil printer or AOI

May 27, 2012 | Auto stencil printer or AOI supplied stencils. You should be able to pick up a low mileage one of these machines for less than an auto. Stay away from clamshell type machines though. I have 5 fully auto machines and I keep the semi-auto as a spare. It has saved my bacon many times and I'd never part with it.

Auto stencil printer or AOI

May 16, 2012 | Auto stencil printer or AOI at AOI later. Also > vitally important to select the right stencil > type for your process and correct blade length > dont just try to stick with one for all your > boards the best compromise is to have at least 3 > sizes which should cover small medium and large > board sizes

How to define solder paste printing height tolerance

May 7, 2012 | Start with targets based on the stencil thickness (for height) and stencil thickness times the aperture size (for volume). * Set reasonable upper and lower control limits (+ 25% and –25 % of the targets, for example). * Next, check the printer set-up by printing and measuring a test print on a

Soldering wires to through holes

Dec 7, 2011 | at removing the pretinning step as a cost savings and receiving PCBs in with the holes already tinned. Our pcbs are usually populated only on one side. My question is if the stencil has openings for the wire hole/pad positions to take care of the top side and the pcb is run through a wave to get the back side, will there be sufficient solder to meet the J standard for sufficient solder, proper fillet, air pockets, ect? I understand stencil size is a factor in how much paste can be put down and the wave will only put on so much. Thank you in advance for your reply.

Assembling one side SMT one side TH

Aug 11, 2011 | Thank you very much for your informative and helpful reply. I have a few more questions:) 1- So for the case 1: should I apply the glue to the PCB with the same method as I apply solder paste? (with screen printer and squeegee). If so, I would guess that the stencil should be different from the stencil for solder paste in terms of the location and size of the holes for each component? 2- For case 2: I think it cannot be applied to our case. Our board is all SMD in one side and all TH on the opposite side. So if I do the screen printing on the SMD side and the P&P and reflow, then I cannot do

estimate solder thickness

Jun 7, 2011 | Boots: Here's several methods for guessing at the amount of solder on your connection: * First, 'Down & Dirty' ** Assume that the solder is flat, which is reasonable since it's 'flattened' by the component package ** Assume 100% paste transfer from the stencil to the board ** You know the stencil

Nub bying p&p, stencil printer and reflow.

Apr 16, 2011 | Nub bying p&p, stencil printer and reflow. auto stencil printer, load the pcb's in magazines and set it in a loader for the pick and place and have the PnP inline with the reflow with an manual inspection inbetween the PnP and the reflow, and finaly a unloader at the end. Is this a good or bad ide? Looking forward for you're clever respond.

Nub bying p&p, stencil printer and reflow.

Apr 13, 2011 | Nub bying p&p, stencil printer and reflow. Hi. I've been looking for SMT machines and have a budget close to 100k total on a stencil printer, p&p + feeders and reflow owen. Witch machines would you choose with this budget? Have any one of you heard of evest?

PCB board house manufacturers NORTHEAST

Dec 26, 2010 | Hi, Here is a brief synopsis of PNC - PNC has been a quality manufacturer of rigid printed circuit boards for 40 years. Located in Nutley, NJ, we are the largest shop in the North East. PNC provides complete turnkey jobs from design, PCB fabrication and SMT stencils. Our Products & services PCB design from schematics PC board Manufacturing - USA PC board Manufacturing - CHINA Flexible PCBs-Quick turn and production - CHINA Laser cut solder paste SMT stencil with reusable ACCUFRAME® Membrane Switches and Graphic Overlays Precision Machining & Sheet Metal Fab.- CHINA Plastic Injection Molding

0402 pad and stencil aperture design

Oct 30, 2008 | 0402 pad and stencil aperture design Hi, Sounds like your engineer does not know what he's doing. We have developed and built hundreds of thousands of boards with normal square pads for 0402, and we just use a 5 thou stencil with 5% reduction and it works well. Decoupling? What is that, and it sounds like he's completely unqualified

0402 pad and stencil aperture design

Oct 30, 2008 | 0402 pad and stencil aperture design the decoupling really tite (still trying to wrap my head around this explanation) If anyone is using round pads for 0402 comps, what stencil apertures are being used . ie round 1-1? Is there any mention in IPC 7351A for this type of pad design? Is there anything i need to watch out for during my production

New to SMT Equipment

Sep 17, 2008 | Don't forget repairing the boards all the special tips for the small parts sounds like you might be placing BGA may need a special machine just for reparing that. some places think they need x-ray for inspecting BGA. type of paste that you going to use. stencil makers. stencil claners. you might

Uncoalesced solder problem in fine pitch IC pads

Sep 11, 2008 | . There is also an area of the pumphead that extends about 2" past any apertures (no direct paste depletion). On the other side of the uncoalesced strip there is step for a thick stencil area (8-10mils vs. neighboring 5-6mils). The thick stencil area is needed to attach a connector using the pin-in-paste method

Used automatic stencil print recommendations

Apr 4, 2008 | Used automatic stencil print recommendations We are a small OEM that runs a high mix/low volume environment. Typical runs are a couple or five hundred boards, one or two products per day. Currently, we are using a Quad DeHart SLC-20 semi-automatic stencil printer. (alignment is manual, printing is automatic, not inline) feeding a Universal

Looks like we'll be BGAing in the near future

Jan 31, 2008 | . My machine of choice is Air-Vac. You can buy usaed units reasonably priced, be sure to get a newer model that can be "factory" upgraded to the Air-Vac latest pre-heater system. Stencil cleanliness is huge. Aperture design is very important. Round holes in stencil can lead to insufficient

SMT Stencil washer machine

Jul 13, 2007 | SMT Stencil washer machine There are many threads regarding stencil cleaners. Here is a recent one: http://www.smtnet.com//forums/index.cfm?fuseaction=view_thread&CFApp=1&Thread_ID=10557

Kester R562 and using lead free components

Jul 6, 2007 | to seeing, me lad. A grainy finish doesn't necessarily mean you didn't form a solder joint, i would say. Also, the fact that you are missing solder on only some of your 0402 terminations would tell this ogre that it's a print, clogged stencil or paste release problems with 0402. You may want to try a 5 -mil stencil, me lad.

Kester paste problems

May 24, 2007 | Here's some quick things to look for: 1. Does your solder paste feel like concrete, does it roll-up into your squeegee blades, and stick to your stencil? If so, your problem is the solder paste. The mixture of powder and flux, or metal load is out of wack. Your particle size is a type 3, which ratio...as the other fellas pointed out. That's your aperture/stencil thickness. There are varying guidelines for different technologies. Some rules-of-thumb, for 20-mil pitch, the range is 0.81 - 1.27, and for 16-mil pitch, 0.62 - 1.12. Have you measured this yet?

Info on MYDATA

Apr 28, 2007 | basic MYDAYA machine(one pick and place head, smallest feeder capacity, basic vision system, manual board handling, etc.)? 2) Does anyone out there used the MYDATA500 jet printer? If so, can that one kindly give me an input on this stencil-less printer machine? Does it really save the cost of the stencils? Or will it be just the same in terms of per-component-cost? What are the economical benefits of this machine? Thanks and please let me know, Basem Thanks you guys for accelerating my help... Basem

Dima's Pick and Place Machines and other low volume P&P

Apr 26, 2007 | $100K for this entire line. We are thinking of getting a Chinese made reflow oven that looks pretty good at $25K. Also, we need to deposit solder using a dispenser as stencil printing will be reserved only for higher volume boards. It will not be practical to have stencils for every board

Solder Paste Inspection

Mar 2, 2007 | results. You may go through oodles of stencils searching for the best aperture design / aspect ratio. And, no the current often used designs rarely work best. Nor does adding extra stencil thickness just for good measure - you'll normally see more stable results with better aspect ratio even

Electromigration Testing

Jun 28, 2004 | talks about contamination level specific contaminants [ie, bromide, chloride, sulfates, etc]. If you know the type on contaminate, it would help focus your search. Next, possible sources are: * Flux contamination from assembly process (typically a halide ion being present). * Inadequate cleaning �s uncontrolled. The heat of the soldering iron makes it spread faster / further. * When using water washable fluxes, squirting flux �all over the board� is reasonable from a contamination control stand-point [not from an employee health / safety stand-point], because the board is cleaned after hand soldering . * In NC hand soldering, the only portion of this flux that is safe to ship is the small portion that comes to soldering temperature. The remainder is BIG trouble. Finally, cleaning NC residues is non-trivial. Done improperly, cleaning could increase your contamination levels, if your flux is not meant

Removal of No-Clean flux residue

Sep 6, 2001 | Removal of No-Clean flux residue are not much more than time machines set back about 13 years. They have their place in the manufacturing food chain but are not commonly used in your proposed application. The most common approach to removing flux is with a spray-in-air system. This technology is available in batch-formats (clean a quantity are planning on removing flux, it would be easier and less costly to remove water soluble flux. Although the removal of no-clean flux is common (our most common application), you will need to use a chemical additive in the wash water. If you are considering an inline system, this will raise the equipment

Large Solder Stencil Apertures

May 6, 2000 | Re: Large Solder Stencil Apertures

Stencil Marking

May 4, 2000 | Re: Stencil Marking

CCGA stencil design

Mar 18, 2000 | Re: CCGA stencil design

Pallet For PCB

Mar 13, 2000 | Breakaways are clearly the best solution for us in manufacturing. A big difference between wavesolder pallets and SM pallets is the need for a flush top surface for stencil to PCB contact in the printer. One vendor has a device which hold the PCB in place and is virtually flush with the PCB

Pallet For PCB

Mar 13, 2000 | Breakaways are clearly the best solution for us in manufacturing. A big difference between wavesolder pallets and SM pallets is the need for a flush top surface for stencil to PCB contact in the printer. One vendor has a device which hold the PCB in place and is virtually flush with the PCB

Re: 0603 Tombstoning

Feb 24, 2000 | I have seen this before, our problem was palladium termination of this component. We could not change suppliers so we use a "reverse homeplate" stencil design to put the majority of paste directly underneath the solder terminations of the component. This reduced our DPMO tremendously

0603 Tombstoning

Feb 24, 2000 | I have seen this before, our problem was palladium termination of this component. We could not change suppliers so we use a "reverse homeplate" stencil design to put the majority of paste directly underneath the solder terminations of the component. This reduced our DPMO tremendously

BGA SOLDER BALL to SURFACE PAD size relationship

Feb 24, 2000 | Hi, - any suggestions welcome... I have a 484 pin ALTERA fineline BGA - ball pitch 1mm (40) - ball size 0.48mm (18.9) What would you recommend for... 1. Surface pad size for the balls of this BGA device? 2. Stencil thickness/type and hole aperture and good printing? Thanks, - Robert

BGA SOLDER BALL to SURFACE PAD size relationship

Feb 24, 2000 | Hi, - any suggestions welcome... I have a 484 pin ALTERA fineline BGA - ball pitch 1mm (40) - ball size 0.48mm (18.9) What would you recommend for... 1. Surface pad size for the balls of this BGA device? 2. Stencil thickness/type and hole aperture and good printing? Thanks, - Robert

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