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QFN Recognotion Problem

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#48577

QFN Recognotion Problem | 22 March, 2007

I am having trouble with the small 4 or 5mm QFN's. There is a small dot on the bottom corner of the component that the vision system is seeing as a lead. We are placing these with our Universal Advantis with a FJ09 head. I would really appreciate any suggestions to fix our "skewing" problem.

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Guest

#48583

QFN Recognotion Problem | 23 March, 2007

How about recognizing it as square package only(like a big capacitor?

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#48585

QFN Recognotion Problem | 23 March, 2007

Can the P&P machine 'learn' the QFN package that's giving you fits?

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#48589

QFN Recognotion Problem | 23 March, 2007

I have tried to teach the part a couple of different ways. I have the component taught as a Quad Flat Pack and I am ignoring two of the sides. This has provided better results but still not consistent.

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#48590

QFN Recognotion Problem | 23 March, 2007

I will attempt the square package this morning to see if that helps.

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#48591

QFN Recognotion Problem | 23 March, 2007

Thanks for the help if any other ideas come up please let me know.

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aj

#48597

QFN Recognotion Problem | 23 March, 2007

we place them as a square - no issues at all.

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Barney

#48623

QFN Recognotion Problem | 25 March, 2007

Check with your UIC sales if your machine can be upgraded to UPS+ 6.2.2 sofware. They have upgraded the vision system so that it can process these kinds of parts.

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CAN

#48821

QFN Recognotion Problem | 2 April, 2007

We have simmilar probelms with a GSM. Lie to it and tell it there are less pins. If there are 6 pins on each side tell it there are 4 and to ingnor the outer 2. then it may miss the dot. Or have it look at just 2 sides like a SOIC.

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SWAG

#48828

QFN Recognotion Problem | 2 April, 2007

If you have upward looking cameras, can you assign the part to the smallest field of vision camera to get the dot out of the search area? Or, I've used patterns on GSM but have not had the need to use them on our Advantis yet. It appears you can make a long list of pattern features in component database, patterns. Could you try the dot as a pattern and maybe make some of the outer, corner legs of the QFP patterns as well - probably a far-fetched idea but maybe worth a try. If you have NPI it might make it easier to tweak these in.

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Haris

#48839

QFN Recognotion Problem | 3 April, 2007

HI I think it is matter of light which is throwing by ur Machine camera, Decrese its light level and then try i believe it may works, because camera only recognises its leads/pins as it reflects back & not the other things, or choose the ODD CHIP/ IC OPTION.I know if it passes some of your QFN, it can pass all.

Secondly, if it pass any of them, then at this point increase its tolerance keeping in mind that you already checked and no problem in any component at all regarding their leads.

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#48847

QFN Recognotion Problem | 3 April, 2007

Thanks for the help everyone. I think that the pattern instead of a leaded component is going to have the best results. Also I checked on the software update and there is not any component database differences between the newest and my current version. They did say however to categorize the component as a bumper-pak to use an algorithm specific for leadless components.

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Barney

#48907

QFN Recognotion Problem | 6 April, 2007

What software level do you currently have on your machines? If you have UPS+ 6.2.x there is a huge improvement. In the SOIC/QFP or any leaded catagory you will find a check box under the vision tab called noise filter. Check this box and the software will ignore the corner dots or pads. All the info passed on to you thus far is very limited and may change from reel to reel or vender to vender. Not going to be too robust unless you upgrade. Bernard Whalen Applications Engineer Universal Instr.

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