stencil cleaning

"stencil cleaning" search results in the Electronics Forums



9814 result s found for "stencil cleaning" in the Electronics Forums

Order by: Relevancy |   Date

CCGA - Stencil design and Reflow Profiling

Jul 31, 2019 | CCGA - Stencil design and Reflow Profiling Peak Center 208 Corner 219 Solder paste : Water soluble paste ( ORL0 - Flux chemistry ) Alloy : Sn63/Pb37 Stencil Thickness : 7 mil Solder paste height : 5.6 to 7.5 mil Regards, Ameen

Ekra E5 question

Jul 26, 2019 | beasts along and we need to. My question is with respect to the side lighting inside the printer. The right side fixture doesn't light up during any phase of the process (or even when we open the door) including learning the stencil, learning paste, and the actual PCBA or stencil inspection steps. It

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

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

0402 chip resistor - settled sideway after reflow

Apr 12, 2001 | Check the pad size. I had this issue before due to the pad size too wide. R&D had change the size of the pad and is solve the issue. Before the pad size change, I had rebuild another stencil with the pad opening close to the component size. It won't solve 100%, but there is some improvement ( about

Stencil buy off procedure

Apr 4, 2001 | check the fine SMTnet Archives for a similar thread

PCB Acceptance Standards

Apr 3, 2001 | go to http:\www.ipc.org. get the following standards: IPC-A-600F Also look at the IPC-6010 series, this may help with your design group. Finally, consider getting IPC-SM-782 and IPC-7525. These are for Surface Mount Design & Land Pattern Standards and Stencil Design Guidelines, respectively

Gold Contacts

Mar 21, 2001 | We're watching more carefully at post-print and pre-reflow inspections for products with the gold finger contacts. Not 100% sure the cause. SMT line people suspect primary cause is improperly wiped stencil. Do you know any other possible causes? We got 3 boards with solder on the contacts (only one

60 Deg or 45 Deg Blades

Mar 5, 2001 | and the stencil.

FBGA Stencil Apertures

Feb 7, 2001 | Look at rpereira on

PQFP with pitch of 0.4 mm

Jan 30, 2001 | Suggestions are: * Limit pad width to 0.008" [0.2mm] * Use IPC-7525 Stencil Design Guidelines * Avoid Type 4 pastes, if you can * Slow down your print head to 0.63"/sec [16 mm/sec] * Consider the suggestions on printing by rpereira in the past week or so on SMTnet [which admittedly apply to a

HTI Auto Print Screen Printers

Jan 9, 2001 | I was wondering if there is anyone out there who is still using the HTI AutoPrint Screen Printers who might be willing to share technical support information. We are having trouble with the machine "finding the stencil" and were wondering if anyone else has experienced it and what your fix was

Solder Paste Height

Jan 6, 2001 | We have talked about using mircoscopes and laser thingies for measuring paste height on SMTnet previously. [Fine SMTnet Archives might give background.] Some people use a 0603 chip cap as a standard. I'm not sure how stencil height relates. Paste volume is the issue. Some people use paste

BGA coplanarity

Dec 27, 2000 | As part of an Intel erratum, they changed their BGA coplanarity spec from .006" to .008". The package is 23 X 23 partial array, .050"(1.27) pitch, 1.220"(31) square. We apply paste onto BGA pads with a 6-mil stencil. From a process perspective, should I be concerned? John K.

Tombstoning 0402

Dec 26, 2000 | If you have a known problem with the parts, then Reject them back to the Vendor. It appears that you have a solderability issue. As for Tombstoning on 0402 chips, this could trace back to the stencil design and/or machine placement. Define Tombstoning, chips on there sides(soldered at both ends

Release difficult from thick stencil

Oct 24, 2000 | Re: Release difficult from thick stencil

Plastic BGA

Oct 24, 2000 | Hi! Good day!! My questions is about PBGA rework the ff are: 1. Is it necessary to reball the plastic BGA module after removing it from the PCB? Can you give me the process and critical requirements?(e.i.stencil) 2.After removing the PBGA module, during replacement, what is the ideal tacking

What exactly is an apect ratio?

Oct 11, 2000 | Hello all, I'm new at this so forgive me if my question seems common knowledge to everyone else. I've searched the archives but found no clear answer to what exactly is aspect ratio and what the best ratio is. All I really know is that it has to do with solder paste size/stencil thickness

Capability Study for Solder Printing Process

Sep 22, 2000 | I 100% agree with Wolfgang. No matter how many in line or off line inspection gadgets, zillion $ printers, and top of line stencils you use, bottom line is a properly trained machine operator who gives a rat about his/her job that makes the difference.

Stencil Cleaner

Aug 30, 2000 | Re: Stencil Cleaner

Stencil Cleaner

Aug 29, 2000 | Re: Stencil Cleaner

Frameless stencil systems - Vectra vs Tetra

Aug 29, 2000 | I wish to gather some information on this relatively new system. I know the pro�s can someone tell

Costing new products - Qty of solder paste

Aug 16, 2000 | Hi Does anyone have a tried and tested method of estimating the mass of solder paste that will be used for an SMD assembly given only the type and quantity of components used. (As well as type of paste, stencil thickness etc) In other words is there some sort of formula that would say allocate

Lead-Free Processing

Jul 20, 2000 | Bob: Please help us understand the effect of changing to lead-free solder paste on our processes better. Compare the following for tin-lead and lead-free solders: * Size of stencil apertures � amount of solder necessary for a reliable solder connection. * Reflow profile and the effect

Solder Balls on 0805 capacitors

Jun 27, 2000 | Hello Bill, Ioan's idea's are good. One more thing that you may want to consider is using a "Home Plate" aperture on your stencil for the aforementioned caps. The idea is to put a smaller amount of solder paste directly underneath the component. This reduces the amount of squeeze out under

BGA rework station

Jun 8, 2000 | Hi There, I know this is a long shot but does anyone in Scotland have a 31mil nozzle for an Airvac rework station that they are willing to hire out for a short period of time? Also is there any papers or sites that can give good technical advice on BGA rework stencils and the best method on using

Adhesive dispension

Jun 4, 2000 | ? 4) What is the thicknees of related to the opening ? 5) What is the method of cutting the opening of stencil? 6) How to measure the adhesive stregth or "green stregth" by cured ?

0201Technology

May 10, 2000 | ?, If you are evaluating the machine's capabilities and not running product why do you need a stencil??? Grab a calibration plate, glass plate, or any other board that suites your needs and use double sided tape. It's pointless to do evaluations if you don't do them before hand! That's just my

Large Solder Stencil Apertures

May 6, 2000 | Re: Large Solder Stencil Apertures

Stencil Marking

May 4, 2000 | Re: Stencil Marking

BGA REFLOW PROBLEMS

Mar 27, 2000 | also strongly recommend using a laser cut stencil with appropriate aperture reductions. Regards Mark

BGA REFLOW PROBLEMS

Mar 25, 2000 | Robert, Have you checked for any form of contamination that might cause the solder not to adhere to the balls? From the pictures you have on the net it appears that you have too much solder on the pads. What thickness is your stencil? If it is to specs have you measured the thickness of your

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

Defluxing Advanced Packages

SMT Equipment