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Solder paste shifted from pad

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#48404

Solder paste shifted from pad | 14 March, 2007

Hi All

i need some help here, currently experiencing connector leg shifted due to solder paste shifted from pad ~0.3mm. I did adjusted the reverse/forward X, Y and titah but still shifted. Product : flex circuit with 28 connector on the panel. Each connector consists of 3 leg in / 3 leg out Printer DEK265 gs(x)

rgd vshan

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#48413

Solder paste shifted from pad | 15 March, 2007

I have seen this when the fiducials are not spaced far enough in the X and Y.

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#48433

Solder paste shifted from pad | 15 March, 2007

how far do you think it should be

rgd vshan

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#48451

Solder paste shifted from pad | 16 March, 2007

Another thing to look out for...

Flex circuits, if not fixtured properly tend to move around and, well, "flex" during screen printing.

At another place I worked, we fixtured the flex circuit on a SMT pallet on the corner tooling pins to "stretch" the flex circuit out, and keep it from moving.

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#48465

Solder paste shifted from pad | 16 March, 2007

I don't understand so please explain in more detail. You say ~0.3mm shifted. In what direction is the paste shifted? is it shifted the very same directions on all panels? Only on this product or even with regular pcb:s? What is the size of the panel and how many flex-board on each? You say that you have adjusted the offsets in all directions?? It does not make sense. Unless this is a multi board panel with every second row of board rotated the opposit way from each other, Or.. More details of your product; panel size, stencil thickness, squegee pressure, print speed, solder paste, fiducial location, board location/rotation in the panel. Just give us a brief summary so that we can try to help you out. We have been through a simular issue a long while and ago. But we need more info about your problem. /Sincererly

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#48482

Solder paste shifted from pad | 19 March, 2007

Hi Vshan,

If 3 legs are on the pads and 3 legs are off the pads, AND your paste is the same, I'd say your boards are made wrong.

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