Printed Circuit Board Assembly & PCB Design SMT Electronics Assembly Manufacturing Forum

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


Solder Fillet on Gull Wing Lead

hardy boy

#17207

Solder Fillet on Gull Wing Lead | 15 August, 2001

Hi,

I have a fine pitch QFP (TQFP100) and after reflow soldering, i got less solder ( not enough fillet) on the toe area but have good fillet at the heel. Does this mean that I have a weak solder joint or is my process not too good ? What is important, the solder fillet on the toe or at the heel ?

thanks in advanced.

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#17209

Solder Fillet on Gull Wing Lead | 15 August, 2001

Oh boy,

I prefer the fillet at heel of course, the toe you can�t trust. The solderable finish of the leads is applied and than the leads are cut leaving the toes without this so much loved finish. guess how that looks after you�ve finished your job.

Take a close look at the parts/leads/toes before assembly to see what I mean.

Wolfgang

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#17217

Solder Fillet on Gull Wing Lead | 15 August, 2001

Spot on!!!

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monkey

#17218

Solder Fillet on Gull Wing Lead | 15 August, 2001

Good fillet at the heel is most critical. Check out IPC standards for acceptable solder joints.

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