Is there an easy way to prevent solder paste appearing on a pad used for a spring-loaded programming connector?
I have called the pad style a unique name 'test pad' and added an exception on the paste laye for a zero size pad. This produces the correct gerbers but I don't know where this exception is 'stored' is it in the tech file or the pcb symbol. Am I able to copy the library shape to another pc without any technology file changes? Is there a better way (I don't like the extra layer method - sounds like a disaster waiting to happen!) thanks Al
Al, I think that the extra layer method is really the best way to proceed. It may sound complicated at first, but as you can specify different colours for various layers, it is quite good after you have got used to it. Initially, if you are not 100% sure of what you've done, double check the gerbers with an independent Gerber viewer such as ViewMate. Also having a "Layers" tab open to toggle various layers helps greatly to visualise exactly what you've done.
I have a component called 'testpad' which has a surface mount single connection. I place this on the circuit wherever I will need to test. This is then routed in the normal way with the 'testpad' component being placed where it is easy to reach with a spring loaded test pin. I use similar 'components' for scope probe loops etc. These are identified by circuit reference as J1 etc.
This is the sort of thing I have been asking for over the years now. It would be best to apply exception to both top & bottom paste layers so if you "flip" the pad it will still have no paste when top or bottom.
I "wished" for the pcb & pcb symbol to be broken into basic parts i.e. copper, resist & paste. Thus when make the symbol it carries the correct information when made into a component. When added to a pcb all the intended information is present without having unique coding for global pad exceptions which is messy !.
The extra (2 + 2) layers for most are invisible unless selected to display and are very useful to apply further enhancements such as increased current capacity by using "lines" on the resist layer over copper plane/shape to later add solder etc.
In your case a pcb symbol with top copper & top resist pads made into a component to later add to any pcb to which if on top has copper & resist cut out but no paste and if flipped then bottom copper & resist cut out but still no paste.
The ultimate aim is to produce "what you see is what you get" without resorting to messy multi layers to subract & add or dangerous "global exceptions" and keeping the Gerber files to a minimum standard format !.
prevent paste on test pads
Posted - 02 Sep 2012 : 15:37:04
