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Squeegee angles

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#40391

Squeegee angles | 13 March, 2006

So, if 45� is theoretically optimal for aperture fill, but 60� is better for defining fine pitch bricks, is 52.5� the best compromise for an all around design, or does it not work that way?

I see blades with either one angle or the other but with the exception of adjustable holders I don't see anything in between.

The reason I'm asking is that we're considering designing our own holders since our printer manufacturer can't see any benefit to taking our money for spares w/o charging us just for the "honor" of owning these machines.

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#40394

Squeegee angles | 13 March, 2006

45* is a common angle of attack. Squeegee blades are commonly manufactured at 60*. The combination of the angle of attack and the blade angle results in an actual printing angle between the two due to down pressure and flex of the blade.

Shear of the solder paste in another factor you need to rachet into your equation. Remember all of this changes as the squeegee wears through use.

Companies make adjustable squeegee holders for OEM printers. Using one of those could save you some work reinventing the wheel [or holder, as the case may be]. Google > adjustable angle of attack squeegee

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#40402

Squeegee angles | 14 March, 2006

"45* is a common angle of attack. Squeegee blades are commonly manufactured at 60*. The combination of the angle of attack and the blade angle results in an actual printing angle between the two due to down pressure and flex of the blade."

Ahhhh, so you're saying the 60� angle I'm seeing referred to on squeegees may be in reference to the angle the edge is ground at? Does that mean that when mounted at 45� and placed under a load that ground edge might be ~parallel with the stencil?

Adjustable holders would be great, but may be out of our comfort zone price-wise. My local rep. will let me know today what we're looking at.

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#40418

Squeegee angles | 14 March, 2006

We're not sure what you're reading, but the angle thing makes sense, right?

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#40419

Squeegee angles | 14 March, 2006

"We're not sure what you're reading, but the angle thing makes sense, right?"

If by "squeegee angle" you mean the angle that the working edge is ground at, yes. If not, then I don't know what you're referring to.

My earlier comments were specifically referencing attack angle, though.

As far as what I'm reading, I dunno, it's one of those "I'm sure I read that somewhere" kind of deals.

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Chunks In Cebu

#40458

Squeegee angles | 15 March, 2006

H Steve, I understand what you're asking except the "defingin fine pitch bricks" thing. Do you mean there is better gasketing, less dog-earing after snap-off or something else? Just curious. I've always used 45 degrees.

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#40472

Squeegee angles | 16 March, 2006

"better gasketing, less dog-earing"

I suppose gasketing could contribute but my assumption is that it's a function of better shearing action between the blade edge and the aperture wall. You get a more consistent shape on the top of the paste deposits with less potential for drag out and smearing.

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Reflow Ovens thermal process improvement