optimun height between lead and pad?

For conventional QFP device, what is the optimun height betw... - Dec 04, 2001 by

Defining the thickness of solder between the lead and the pa... - Dec 04, 2001 by davef  

Andy

#18328

optimun height between lead and pad? | 4 December, 2001

For conventional QFP device, what is the optimun height between lead and pad? 50 microns or 100 microns? What is the factor affecting this height?

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davef

#18330

optimun height between lead and pad? | 4 December, 2001

Defining the thickness of solder between the lead and the pad, J-001 states "Properly wetted fillet shall be evident." J-001 is available from http://www.ipc.org.

Factors that affect this are: * Amount and composition of solder * Amount and composition of flux * Lead shape, solderability protection, and solderability * Pad flatness, solderability protection, and solderability * Component weight * Reflow profile

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