1. Home
  2. Electronics Design
  3. Layout

Layout

When designing footprints for do you need to add information for the solder resist layer or does the application compute all non-pad area's and apply a solder resist? This seems to be the case from looking at a rendering of the board I'm working on as the solder resist layer colors all but the pads, although a bit of an expansion off the pads.

Looking at some footprints shows that the top solder layer generally is pad related to and is an expanded version of the pads. Curious as to why solder paste masks are not also automatically generated? I do realize in some cases you might not want a solder paste mask.

What are the mechanical layers for? Are they just for visualization of mechanical features or do they actually get used in anything?

I created some footprints I needed and I just added the copper pads to the top layer without adding solder mask, mechanical stuff, etc. Is that bad practice or is it ok?

Reply to
Bobby Joe
Loading thread data ...

Not usually, unless that part has special requirements for the solder mask.

The "solder mask expansion" is a usually global value you'll set for the entire design. But others like the more manual approach. Problem with manual though is it's easy to miss something. I use the 3D view (in Altium Designer) to check for solder mask problems before sending a board for manufacture, much easier than 2D modes.

They should automatically be generated in any good package, if you don't create any one on your footprint.

Heaps of things - layer stack-up and other manufacturing info, routing v-grooving detail, dimentions to name just a few. Limited by your imagination. No standards here, everyone uses them for different purposes.

That's fairly normal practice unless the part needs something special. e.g. exposed pad under the chip etc.

Dave.

--
---------------------------------------------
Check out my Electronics Engineering Video Blog & Podcast:
http://www.alternatezone.com/eevblog/
Reply to
David L. Jones

k.

ual

g.

rnatezone.com/eevblog/

Thanks David, I think you answered all my questions ;) And without any grief ;)

Reply to
Bobby Joe

Design notes, calculations, assumptions, dimensions, special alignment lines or grids, placement patterns, fab drawing notes, assembly notes.

This board has a layer that was imported from Autocad. We often do the Autocad first and design the board around that.

ftp://66.117.156.8/J245_R5.gif

John

Reply to
John Larkin

One of the things you need is a board outline. You can either put that on a separate layer that doesn't have anything else, or use something distinctive like a 0.001 (inch or mm) wide line on a mechanical drawing with lots of other info. It depends on what your board house wants.

Somewhere, you have to specify the layer thicknesses, aka stack-up. You may not need a drawing if you pick one from a set that your board house offers.

--
These are my opinions, not necessarily my employer\'s.  I hate spam.
Reply to
Hal Murray

ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.