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IPA versus Stencil Cleaning Solution

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#77726

IPA versus Stencil Cleaning Solution | 13 June, 2017

For many moons, I have used IPA for our cleaning tanks within out DEK systems. Now we have a new engineering team and he would like to try a stencil cleaning solution (DEK PRO XF). Can everyone tell me there pros and cons of using each of these over the years? Not necessarily DEK PRO XF but any cleaning solutions. We did see a study of IPA eventually over time leaving a film of paste on the walls of the stencil which led to this decision. We also have an ultrasonic stencil cleaner that at the end of the work order we will send to for a well-deserved cleaning.

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#77728

IPA versus Stencil Cleaning Solution | 13 June, 2017

> For many moons, I have used IPA for our cleaning > tanks within out DEK systems. Now we have a new > engineering team and he would like to try a > stencil cleaning solution (DEK PRO XF). Can > everyone tell me there pros and cons of using > each of these over the years? Not necessarily DEK > PRO XF but any cleaning solutions. We did see a > study of IPA eventually over time leaving a film > of paste on the walls of the stencil which led to > this decision. We also have an ultrasonic stencil > cleaner that at the end of the work order we will > send to for a well-deserved cleaning.

We have a few Ekra screen printers and we switch between the 2 IPA and AIM stencil cleaner ever few months because it seems there is a oil additive to the stencil cleaner that builds up over time in the valve and clogs it so we use the IPA for a few days to clean it out.

I was told IPA is not good for stencils long term that is why we don't stick with just the IPA, but could of just been a sales pitch ?

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#77729

IPA versus Stencil Cleaning Solution | 14 June, 2017

I have been using IPA for more than 3 years with no damage to stencils. what some cleaning solvent manufacturers claim is that you get better separation with their products, some even recommend nitrating stencil to enhance separation and avoid paste detaching from PCB. if you have realy small footprints maybe you should test it for your self and see what works for best.

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#77732

IPA versus Stencil Cleaning Solution | 14 June, 2017

In my experience there is no need for wet wiping stencils.

We run 0201'and micro BGA's daily with no issues.

If you are having paste release issues, I would be looking at other things. Aperture area aspect ratio, aperture design, land design, solder paste...to name a few.

I'm personally not a believer in "nitrating" or nano-coatings.

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dwl

#77733

IPA versus Stencil Cleaning Solution | 14 June, 2017

What's Nitrating? That's a new one on me

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#77734

IPA versus Stencil Cleaning Solution | 14 June, 2017

IPA is flammable and that is why no company will tell you to use. I've used many solutions and IPA works just as fine as any other solution if not better. Definitely use solvent in your cleaning. If it was meant to clean without solvent we wouldn't take a shower, but use dry towels only.

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#77735

IPA versus Stencil Cleaning Solution | 14 June, 2017

Nitrating is new to me too. I assume it means nitride coating.

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#77736

IPA versus Stencil Cleaning Solution | 14 June, 2017

Evtimov,

I am curious...why do you say definitely use solvent ? We have never used it and never had issues.

All of our boards go through SPI.

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#77737

IPA versus Stencil Cleaning Solution | 14 June, 2017

Sr. Tech,

Just think about it. How do you clean your stencil after you finish the job? Dry wipe and put it on the shelf? Dry wipe will work to some extent for simple boards, but your stencil will never be perfectly clean like if you use solvent. You can't clean good anything without using solvent. There always will be these small particles that you can find if you go under zoom. Your flux levels in your paste will change as well with time and that wouldn't improve your performance too. If it was obsolete, machine manufacturers wouldn't put it there, neither you will need machine to clean your stencils(this one is using solvent as well)

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#77740

IPA versus Stencil Cleaning Solution | 14 June, 2017

sorry, I can't give you best solution for IPA versus stencil cleaning. But if you need new stencil, I can recommend you one, five-star praise supplier, they have stencil or with frame, various size at cheap price below 30% market price http://www.pcbgogo.com/j

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#77741

IPA versus Stencil Cleaning Solution | 15 June, 2017

Hmmm....

When I clean my stencils after I run a job, it is to clean the paste off the stencil so it doesn't dry out in the apertures and on the stencil surface while it is being stored.

Wiping the stencils during production is to clear the paste off the bottom of the stencil. Not wash the apertures out with chemistry. If you are having paste release problems, I'm not sure wet wiping is the answer to your problems.

As far as wet wiping being obsolete, not sure on that.All I'm saying is we have never done it in 30+ years and there are NO issues that I could ever associate with not wet wiping. Personally I am a little dubious about wiping cleaner up into the apertures then screen printing solder paste through them and wondering what that is doing to my flux chemistry......??

We dry wipe highly complex stencils (daily) with a multitude of micro apertures. No problems.

I'm not the judge...my SPI machines are.

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