stencil cleaning

"stencil cleaning" search results in the Electronics Forums

9861 result s found for "stencil cleaning" in the Electronics Forums

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QFP rework

Apr 1, 2004 | that must be soldered to the pad of the PCB. After removal of the component, we would clean the pads to remove excess solder and wick the excess solder from the ground pad on the PCB. A new component would be used for installation and prior to placement, a dab of solder paste must be placed on the ground


Mar 30, 2004 | If speed is truly an issue, migrate to no-clean. However, this is not always an option. Why bake after 1st smt pass? Because you are probably not drying completely under the BGA components, and/or you are pushing water into the parts/boards/ vias and having out-gassing or blistering

PCB post reflow cleaning

Mar 26, 2004 | Hi Patrick, With all due respect, it is easy to quantify zero. You made a claim that your fl

Flux Classifications.

Mar 9, 2004 | chemistry being used. Assemblies processed with high-solids rosin fluxes (RA, RMA) can tolerate higher levels of chloride due to the encapsulating nature of the rosin. Organic [water soluble] fluxes and no-clean fluxes are generally based on resins or very low levels of rosin, and so do not have

Oven Profile

Mar 8, 2004 | . Board is generally heavily populated and densely grouped. My old profile was 150/160/170/180/210/220/190. Because I was afraid of thermal stress I lowered the temps. Is this a good profile? Or is there room for improvement. BTW, my working environment is clean, temp around 75deg with maybe 50%RH. I

bulbous joint

Feb 23, 2004 | low solids no clean rosin flux 1 - 1.5% (Higrade 3541 or similar)and keep preheat around 90C topside not too high or flux will move away. This will give you fix immediately. Then look out for too much convection as very dangerous to fluxes. Finally fix wave properly as either too deep or shallow

Post reflow cleaning

Feb 18, 2004 | You have two choices� Change your paste or beef-up your wash chemical. I�ll let others discuss p

QFP Removal

Feb 17, 2004 | specifics on what alloy forms when co-metalization occurs. I can tell you that this alloy has a low temp melting point and that it cleans up rather easily. Hope this helped somewhat. For the record I dont have any association with this company, I saw a demo at a show and figured I would give it a try

PCBA clearing machine

Jan 29, 2004 | Hi Eric, Here are the manufactures of batch-format aqueous cleaning / de-fluxing systems: Aqueous Technologies (909) 944-7771 China Distributors / Service Centers:

Goldfinger protection

Jan 2, 2004 | . Both will work. We use the fiberglass ones for cost. Just slip them on before wave and remove as they exit wave. We wave solder 1 product line @ 1500/month with these and they have lasted up to 1 1/2 - 2 years before we have to start replacing them. Our process is no-clean. You can also use the water

To overcome human problem

Dec 22, 2003 | Hi,I am a Mfg. Engineering Tech. and do Maintenance on all of our Equipment. 4796 HSPs, Dek 265 LT screen printers, GSMs, ect. We have 6 lines of equipment with certain operators assigned to each line, and you can really tell which operators do or don't do daily maintenance, or proper clean up

Tarnished surface upon cleaning with DI water + saponifier

Dec 17, 2003 | Your conversion coating will not do dip about preventing corrosion of the aluminum surface when soak

Heller 1088 Reflow Oven

Nov 17, 2003 | As you have seen, the 1088 doesn't need much in the way of P.M. We recommend: --Monthly vacuuming in the base and under the hood (ie Dust Bunny control) --Lubricate Edge Hold Conveyor Chain and leadscrew (if the Edge Hold Conveyor option is installed in the oven) --Clean Thomson rods with alcohol

How to clear the non-clean residue out during soldering

Oct 8, 2003 | Hi Dave: I'd second you.Thanks for your effort and can you give me the hints about correct reflo

lets see a show of hands

Aug 13, 2003 | You have not seen kicking and screaming as 1,1,1,Trichlorethene phase out actually had a drop in process with cleaning soaponifier options. Lead Free is not a drop in process by any means. Gary I hope the kicking will be with soft shoes my friend.We here are waiting as implimentation dates keep

Copper oxide

Jul 31, 2003 | 'm not sure, when my customer told me that this could be a corrosion. Could any of you guys tell me what exactly is this greenish thing ? The flux we use is NR330 no clean. Inputs are welcome.

CP642's vision process error

Jul 28, 2003 | device.(It's just happening when placing 0402 RC chip.) And the monitor shown the device sharp is indention. This problem will make the machine drops a lot of devices. But the device's PDG setting is fine. I had tried to exchange the VP board and use the alcohol to clean the transfer cable and connector


Jul 18, 2003 | The parts adhere solder very well. It does not pertain to a certain part on the board either it is

Cracks on ceramic capacitors.

Jul 7, 2003 | ultasonic cleaning process be careful about the frequency setting. To low of a frequency setting will be equivalent of hitting the product with a hammer. Some other things that you may want to look at is if this occuring during your process or is it a incoming material problem. If not then you should also

Technical Devices NuClean 324

Jun 20, 2003 | Based on the current conditions in the industry, I think ethics are out the window. I have seen it

Quad Machines? Good Points / Bad Points

May 22, 2003 | Hi Jon, I recently had the opportunity to look over a used IIIc converted to a IVc. The documentation, software and spare parts supplied with the machine seem more than adequate, however, upon spending several hours cleaning, oiling, familiarizing, tightening and replacing, I can not even program


Apr 29, 2003 | . Alpha Metals used to publish a dross inclusion test. [Chyrs Shea talked about this test a couple of years ago here on SMTnet, but unfortunately many those threads have been disappeared.] The test involved melting solder samples in clean beakers with a cover layer of water white rosin flux. Alpha

Soldering nickel strip

Apr 28, 2003 | solder failure. Nickel forms a fairly tenacious oxide. Gold is plated over nickel in ENIG solderability protection to prevent nickel oxidation. So, you need to select and qualify: * A flux that can remove this oxide and then allow soldering to the nickel. * A cleaning process to remove the residues

Air Vac Mini Wave Process

Jan 27, 2003 | chemistry they used. The boards can be cleaned with a Aqueous batch cleaner after this process. Looking for some good recommendations.... Thanks, Kevin

Making a BGA stand up

Jan 13, 2003 | than 30-35% ball collapse. ** Snip off some stainless steel shim stock and just tack them to the PWB with a drop of flux. Remove after reflow, but before clean, so they don't get wedged somewhere they should not. ** Use glass spheres (adhesive staked), but they are a nuisance to get hold of the right

Pencil Use writing onto IC

Dec 11, 2002 | contamination for the close-loop Aqueous Cleaning system*machine*? appreciate if anyone could share their experiences and scientific opinions, on this issue of using pencils to write identification markings on IC packages? Thanks.

Board with immersion Tin

Nov 25, 2002 | Hi, I made a board wich I plated with immersion Tin, I tought it should be the same result as we had with tin lead but we ran into a weird problem. WE use a 63/37 no clean paste and on the Board with Immersion Tin the solder just make a ball ON the pad...we ran the same profile with a board

Help! BGA Socket / BGA Direct Placement

Nov 14, 2002 | Kevin, I have done the following process to a similar problem: 1. Plug holes (even to both sides of the board) 2. Clean any flux left on the surface, especially on bottom side. 3. Apply Kapton tape to the bottom side, you mite want to apply 3 layers. 4. Apply a small layer of paste flux to the top

type 4 paste & type 5 - environment factors & process parameter?

Nov 13, 2002 | . Thanks. Also we came to know from our off shore SMT associates, about the KESTER Hydromark 522 paste (WS?), and saw some reference to it in the SMTnet, just how good is it? and any unique soldering process considerations that must be addressed during use? how about any cleaning (WS?) needs *hint: ionic

Re-soldering QFP with thermal pads

Oct 31, 2002 | We do this all of the time, This is what we do but I would be interested in other methods. 1. Remove component with BGA type rework station 2. Wick off lead pads only, verify/create even solder surface on the thermal pad on the board 3. Apply no-clean solder to the component pad (just enough

Fine Pitch QFP100 Solder Joint - Need Help!

Oct 30, 2002 | I would perform a simple solderability test per ANSI/J-STD-002. You can do this using a compatable no-clean flux like Indium NC771 and a solder pot. If the leads wet well you do not have a solderability problem. I did not notice what plating was on the board or if you are reflowing in Nitrogen

Palladium leaded devices IPC610 class3 acceptable

Oct 22, 2002 | We are a military contractor and need to build to IPC610 class3. We are receiving many parts with palladium leads and currently use a No-clean solder paste. We have evaluated OA pastes with very little improvements. Without a touch up of all leads these are rejectable as per the standards

Water soluble flux

Oct 22, 2002 | -5%, Dimethylamine hydrochloride 1-5%,IPA 60-70% and the rest is surfactants. Would any tech-netters know of a drop in replacement water soluble flux, No-clean is not an option) with roughly the same ingredients (will make my qualification a lot esier) The boards are placed through a closed loop EMC di cleaner set

Cleaning Oxides from BGA's

Oct 19, 2002 | You know I knew I used this forum for a reason, probably the most complete knowledge base going.

SMT Component Design Requirements

Oct 18, 2002 | What is the determination of poor soldering fails pull test, non-wetting, visual)? I have never heard of an SMT component that has leads higher than the body of the component. Refer to IPC 782 it provide the guidelines for SMT standoff height (cleaning is the concern). .1mm below the body

About the PCB gold finger contamination.

Sep 19, 2002 | Thank you ur reply Dave. Let me explain our COB workflow: 1. unpack PCB (FR4,LPI,HASL)(the thickness of gold and nickel we can't be find)(No SMT before) 2. clean the pcb by rubber 3. blow the pcb by di-ionic gun 4. attach die by adhesive gel 5. cure the adhesive gel at oven (100 C ,30 min) 6

pc board defects

Sep 15, 2002 | defects as follows: * Solder paste screening: 63.8% * Component placement: 15.3% * Reflow solder and cleaning: 15.2% * Incoming components: 5.7% The industry is doing things differently now. We has a similar discussion on SMTnet. Look here:

Refreshing PCB Solderability

Aug 14, 2002 | . I'm sure others will want to give valid reasons to be cautious, regardless of rework method you can pursue. Why not trying brushing on some paste flux and run the boards (unpopulated) through the reflow oven. It seems to me a water soluble paste flux would clean the pads, then you wash the boards

oven resin from adhesives

Aug 13, 2002 | We don�t use this glue. What does Heraeus say about your condensate? [I'm With the previous poster. Your condensate sounds like goop from NC flux not glue.] How to clean out a 3 meter length of chimney? Depends on your tolerance for pain * Take it and a handful of quarters down to the coin

Contract Manufacturing in USA

Aug 10, 2002 | Dear Freinds, We are having 18000 sqfeet airconditioned space for pcb contract manufacturing.We had chipschooters,through hole machines & fine pitch placement machines with international standard.In addtion we had clean rooms & wire bond facilities.We also have the largest fiber coupler

No Clean Selective Solder

Aug 2, 2002 | I can't think of any off hand other than the Ersa which is massive and from when I used it a pain in

Indium No-clean and Inert Reflow oven (N2)

Aug 1, 2002 | we run the paste in both air and n2 depending on customer requirements again it run's fairly well in

ENIG poor wetting

Jul 30, 2002 | Print 78, a no-clean solder, right? Improper amounts of Cu, Au, Al, Zn, and S can cause decreased wetting and spread. So, have you been adjusting your paste? Nitrogen will improve wetting in some NC fluxes.

Corroded ASIC's

Jul 16, 2002 | Questions are: * What is this green material? * What does the green material look like? * What the impact of this material on the long-term reliability of your customer�s product? * What flux did you use to solder these boards? * How were the boards cleaned after soldering? * What is the conformal

solder pop out from via hole at secondary reflow

Jul 8, 2002 | Hi Guys, We prints solder paste on via hole as the holes are used as the test points. This is a clean process. In normal production, upon completion of a primary side, board will proceed to secondary process immediately. The problem happened when brds which were completed primary side and brd

Solder particals in the oven?

Jun 5, 2002 | ever, you are going to have this problem. It is imperative that your operators have clean hands when handling boards with gold fingers. I really do not think that your oven is blowing molten solder around. Although, I have had several operators try to convince me that the oven is blowing their parts

Solderball Removal

May 23, 2002 | coz of fragile lead components that may "vibrate-drop" off. 3) anything more stronger than "Genosolv 2004"(NC cleaning solvent) seems to corrosion away the surface layer on the IC leads. which gives a porous dull metallic apperance.

Gold plated PCB's

May 10, 2002 | action during the Reflow processing. seems to be pre-dominent for NC pastes. the text was actually informing the reader the virtues of using WS pastes, as WS paste use will warrent Aqueous Cleaning of the post-reflow PCBA. (my understanding is of limited qualification to pass any judgement on such a

Assembleon CSM/GEM Feeders - Any tips or tricks for repair

May 6, 2002 | Hello Do any of you out there with Philips/Assembleon machines have any tips or tricks to repairing there feeders. I call Assembleon and one guy tells me to clean the heads and the feeders with a small lint free brush and to not use any oil on the head. Then another guy said to use a little 3-in-1

Water Quality Requirements to wash boards

Apr 15, 2002 | , is suggesting that you read AC-62A � �Aqueous Post Solder Cleaning Handbook� silly?

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