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Wire Bonding fiducial mark specifications

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GS

#47090

Wire Bonding fiducial mark specifications | 30 January, 2007

Please who can help me?

I am looking for fiducial (cross shape) mark (target mark? Swiss mark?..)specifications used when COB wire bonding on PCB laminate.

Pad pitch should be 250umm may be 220umm?).

Mainly need to know which are the tolerances on the cross mark dimensions (+/-0,...? mm ).

At the moment I do not know W-B machine type and machine accuracy..

Thank you

Regards.........GS

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flipit

#47109

Wire Bonding fiducial mark specifications | 30 January, 2007

Hi,

I would not be too concerned about what the shape of your wirebonding fiducial is. Cross, Square, Diamond, Circle, will all work well for you. I use a "+" and a diamond. Your machine magnification will be great, so don't make the fiducials too large. I use a plus or cross with 0.2mm wide spokes and total cross size of 0.5mm. Same with the diamond or square or circle. They should be no larger than 0.5mm in size. Also your bonder will have pattern recognition so you could use whatever type of shape you want to use. I have recognition issues sometimes with a plus or a cross. The spokes don't always etch clean and a cross or plus sort of turns into a diamond.

What bonder are you looking at? Wedge or ball? The H&K wedge is nice. I use a Panasonic gold ball bonder.

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GS

#47130

Wire Bonding fiducial mark specifications | 31 January, 2007

Thanks a lot flipit,

I am not directly involved in this "problem" but is my friend that have his CM rejecting PCBs because it says the "+" mark (spokes lengths) are out of tolerances. It seams CM bonder's require tolerance +/- 0,05(? not sure). I do not know so many details but I am waiting to get some additional.

What I recall is that they are using "+" mark, 5,8 mm and the spokes are 1,5 mm long (may be +/- 0,1 mm?)

Wire is Aluminum, but I do not know the diameter and if bonded by wedge or not. Also about bonder I do not know brand and type and capability.

I will come back as I will have more details.

Best Regards........GS

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