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Dip Fluxing Cavity Depth

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FD

#63613

Dip Fluxing Cavity Depth | 24 January, 2011

Has there been any studies on the effect of the depth of the fluxing cavity for dipping PoP components? I've heard that the cavity should be 50% of the ball diameter and I also heard that the cavity should be 2/3 of the ball height (which may or may not be 50% of the diameter).

Anyone out there been doing PoP and dip fluxing and can help guide me in the correct process?

Is there a general rule of thumb or guideline for the proper depth of the fluxing cavity?

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#63634

Dip Fluxing Cavity Depth | 26 January, 2011

From our experience with our gel fluxes the depth of the flux cavity can be 30% ~ 70% of the ball diameter. You'll probably need to do some tests to find the optimum for your process. If you have really fast movement on pick and placement machine then you tend to need more flux to make sure the POPs don't shift. Other factors that affect the volume you need is level of solderability of pcb/bga. If you are using dipping paste then the depth of the cavity may be dictated by the amount of warping of the bga device....deeper cavity to put more paste on the bga sphere to fill a bigger warp gap.

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