|
Peter Johnson
United Kingdom
511 Posts |
 Posted - 21 Dec 2006 : 06:35:27
|
The design rule check is failing because the pads aren't connected. There are two ways of tackling this. One is the way you have already tried. The other is to use two pads, but link them with a copper shape. This gives you a lot more freedom with the profile, and you can link it automatically to one of the pads using the shape properties.
Ideally you need two connection points in your schematic as well, as if one of the pads has been connected 'on the fly', it will automatically be disconnected if you ever forward design changes.
The biggest disadvantage of using the copper shape solution is that you need to manually take account of the solder resist clearance. Do this within a custom technology file, and you won't need to reinvent the wheel:
First create a custom layer type for your resist. (See Layer Types in the on-line help for more details of this.) Then create top and bottom resist layers using the new layer type, and save this in your custom technology file. Use this new technology file when you create the pcb symbol or open it for editing. Add an oversize copy of the copper shape on your top and bottom resist layers, and save them with the symbol. If you use the same technology file for new designs, the resist shapes will remain part of the symbol, and will take care of themselves. When you create your output, use your resist layers to create production files instead of using the automatic 'Resist' option for your copper layers.
There's more information in the FAQ section under the technical link on the home page. Look for the FAQ 'Creating a solder mask for BGA components'.
Peter Johnson
Technical Support
Number One Systems |
 |
|
Overlapping pads in components
