SparkFun Forums

[jvd]

Hello,

I'm designing my first PCB for SMD components in Eagle.

About this SMD inductor (see datasheet page 1 http://www.bourns.com/data/global/pdfs/SRU1038.pdf) I'm doubting about drawing the package.

As you can see this component has its pads underneath the package (slightly visible from the side when I inspect the real thing), so would I be correct if the "recommended layout" in the datasheet is only for reflow soldering, and I need to make the pads much wider to do this by hand soldering?

[waltr]

That is correct, the recommend pads are for reflow soldering.
Where I work we do need to repair board so we always extend the pads just enough to get a soldering iron on the pad.
This takes up more space on the PCB but does make the board hand workable.

[jvd]

Extending the width of the pads on both sides by about 3mm (0.11 ") will do then?

By the way, will a recommended layout work for handsoldering TSSOP/MSSOP (0.65 mm pitch) and TSOT (1 mm pitch) components or will I also have to extend that?

[leon_heller]

You shouldn't need to extend the pads for hand-soldering, I only do it for QFN packages. 3 mm is far too much, anyway.

Leon

[jvd]

OK 1 mm it will be then, thanks.

[NleahciM]

Hello,

I'm designing my first PCB for SMD components in Eagle.

About this SMD inductor (see datasheet page 1 http://www.bourns.com/data/global/pdfs/SRU1038.pdf) I'm doubting about drawing the package.

As you can see this component has its pads underneath the package (slightly visible from the side when I inspect the real thing), so would I be correct if the "recommended layout" in the datasheet is only for reflow soldering, and I need to make the pads much wider to do this by hand soldering?

It looks like the pads are sticking out 0.4mm past the edge of the inductor. That is enough to hand solder. No need to modify the footprint in my opinion.

[leon_heller]

I don't usually have any problems hand soldering anything with a footprint intended for reflow soldering. The correct size tip and temperature are important, of course, and fluxing the pads first is a good idea. I use a no-clean flux pen.

Leon

[jvd]

I'll stick to the recommended layout then. Thanks for the recommendations, will be one pcb design less to trash

Leon which pen do you use? I've used the cheapest one available (http://uk.farnell.com/edsyn/fl88/flux-d ... Ntt=876732) but haven't compared to other products...

[leon_heller]

I use an Electrolube SMF12P. Same sort of stuff.

Leon