Hi Jack

In a previous life I did deal with tons of MELFs on military boards, using the U-shape pads.  Worked great.

I'm now dealing with an avionics customer who uses them (diodes and resistors) on rectangular pads.  We do see a lot more skewing, but within spec.  So they don't look as nice but are acceptable.

My opinion, with the U shaped pads the boards will be easier to inspect.  Skewed parts have to be looked at, parts that are clearly centered on the pads don't have to be considered.

regards,

Graham Collins
Senior Process Engineer
Sunsel Systems
(902) 444-7867

On 12/4/2017 12:55 PM, Jack Olson wrote:

I am using MELF components on my current design,
which I haven't seen much this century.
But I remember way back when we used "U-shaped" land shapes.

I notice the current Land Pattern standard (IPC-7351) recommends
rectangular,
but at least one person has suggested using U-shaped "just in case".
I generally resist that kind of philosophy unless there is science behind
it.
Is anyone using U-shaped pads anymore?
(Is anyone using MELFs anymore? smile)