Though I am just trying to make a basic board with PBCEditor 15.7, I am having problems with thru-holes on my board. I am not sure if it is a padstack issue or somethign with the way I am defining the planes.
Thruhole Padstack (1.78 drill diameter):
BEGIN/INTERNAL/END: Pad: 2.78, Thermal: 2.78, Anti-pad: 3.5
In my layout, I create a plane on the Positive GND layer with Shape->Rectangle, set the class to Etch and subclass to GND, draw the rectangle, and associate it with the net Gnd.
My expectation is that Thermal Reliefs and Anti-pads will be drawn on the GND layer accordingly based on whether they connect or not... but it seems that all layers are getting Regular pads drawn. Am I doing something wrong when adding my Etch rectangle? I get many DRC errors and things just don't look right.
Thanks for any help,
From what I've seen, thermal and anti-pads (as defined in a padstack) are only used on Negative planes. Since you've got Positive planes (and if you have dynamic shapes), you can set the shape parameters on thru-hole pins to get your thermals.
In reply to Randy R:
Have you went into SETUP/Design Parameters and 'refreshed' your planes? If not, that might fix your issue.
Good day. Mitch
In reply to Cadpro2K:
Thanks for the advice guys, but I am still unable to get anything to work, using either positive or negative planes. The PCBEditor15.7 Documentation says what is stated below, whichseems to imply that it would automatically put in the right thing. But, this is not what I am seeing.
So, from what you are saying, it seems that if I want a pad that connects to the (negative) ground plane, if I define "circles" for the antipads, it should not connect them, correct? that is not what I am seeing. Can someone please walk me through or point me to a step-by-step example of how to actually design a thru-hole/via and plane for PCBEditor? It is my first design with this software, as is probably clear from all my questions.
"Standard Pad ShapesAllegro PCB Editor displays pads using standard geometric shapes. On the Layers tab of the Padstack Designer, you can choose from the pad types illustrated below in photoplots. Pad Type Description Graphic Displayed Regular Positive pads (black), with one of the following regular shapes: Null Circle Square Rectangle Oblong Octagon Thermal relief Used instead of regular pads to absorb heat conducted through connect lines. Thermal reliefs can be: A negative pad on a positive copper area (shape). The thermal relief may be plotted as a regular pad flash (circle) with two lines. A positive pad on an embedded metal layer that distributes a voltage, such as power or ground. Anti-pads Negative pads (clear, surrounded by black), usually a circle, to prevent connection of a pin to an embedded metal layer. ...Each pin can have all types of pads (regular, thermal relief, anti-pads, and custom shapes) defined on every ETCH layer of the design. For negative artwork layers, Allegro PCB Editor uses thermal reliefs and anti-pads. For positive artwork layers, Allegro PCB Editor uses just three regular pads. This means a pin can be put anywhere on the design, and Allegro PCB Editor photoplots the correct pad, whether the location is in an open area or inside a filled shape.Photoplot Pad DataWhen you create plots, Allegro PCB Editor uses the padstack information to write the photoplot pad data for a pin on a particular layer. Allegro PCB Editor determines the pad types for photoplotting as follows:How Allegro PCB Editor Determines Pad Types for Photoplotting
If the Pin Is... Uses Pad Type... * Not in a filled area on a layer being photoplotted, such as a shape or rectangle: Regular pad on positive artwork
* Inside a filled area on a layer being photoplotted and the pin shares the same net as the filled area:
A thermal relief pad created by positive artwork, or a thermal relief pad drawn by positive artwork ==========================================================
* Inside a filled area on a layer being photoplotted, but the pin does not share the same net as the filled area: An anti-pad created by positive and negative artwork
In reply to EllieRye:
Aha, figured it out (thanks to the first tip). I did not realize I need to change the shape to "dynamic". Now I did and both thermals and antipads work fine for positive plane layers.