Forum

I have this IC from TI that has a 0.65mm pitch
http://www.ti.com/lit/ds/symlink/pcm1804.pdf
3 pages before the end of the datasheet, they give their recommendation about land patterns of the IC :
- the exposed metal should have a width of 0.45mm
- this gives 0.2mm between copper pads
- TI recommends a soldermask clearance of 0.07mm around the pads

But at the same time on this page :
https://uk.beta-layout.com/pcb/technology/specifications/ in Soldermask section:
- The minimum soldermask bridge is 0.1mm
- The minimum gap is 0.075mm
so that gives between the pins : 0.075 + 0.1 + 0.075 = 0.25mm

How can I solve this conflict? Go for the non-preferred soldermask defined openings? How would this work for an IC with 0.5mm pitch?

Thanks,

Raphael

Dear Raphael, that`s correct what you said.But that`s our rules in pool. Maybe you can change the landing pad a little bit. For .5 mm we can`t garantee in pool. Please ask in such cases our sales. They will find a solution.

Best Regards,

Your Beta Team

Sorry I didn't see your reply as it got weirdly mixed with my original question.

Thanks for your reply, I'll change the landing pad a little bit, the IC pins are max 0.38mm and it fits if I put the pads to 0.40mm, I guess the reflow process will work with that.

Thanks for your reply about the 0.5mm pitch.

Have a good day,

Raphael

Hi...to avoid solder bridges, get the right solder flux. I use 2331zx water-soluble flux and bridges seldom form and, when they do, they’re easily removed. Then wash the board with distilled water, dry it, and you’re done.
If you must play with the pads, the thing that’s mostly done is to extend them outward to make it easier to apply the soldering iron. This can be helpful with QFN packages but isn’t really needed for gull-wing packages.