Mentor Boardstation Neutral Files

Overview

The Mentor Neutral File reader takes as input a Neutral (.NEU) ASCII file. For directions on creating this file in Mentor Boardstation, please see the original system file generation section.

Versions Supported

CAMCAD supports Mentor Neutral generated from Mentor Boardstation V.8.x. and later.

Specific Import Procedures

The Mentor Neutral import procedure does not vary from the generic procedure described in the Importing Section index. Simply choose the File | Import command from the menu or the Import button on the Main toolbar. From the list of licensed import modules select "Mentor Neutral File Read" and click OK. Next, browse to your Mentor Neutral file and click OK to load the file (neutral files do not have a set extension and the File Open dialog will only display files with the extensions of .NET and .NEU for the neutral file and extensions of .TRA and .WIR for the traces file). Finally, check the log messages and select "Place at Origin and Fit Page to Image".

The default rules file is Neutral.in and is found in the CAMCAD directory. See Neutral.in File for more information regarding the use of this file.

Tips, Notes and Importing Questions

Mentor Neutral files Generated from other sources (Other than Mentor Boardstation)

Mentor neutral files generated by sources other than Mentor Boardstation can not be guaranteed to successfully load into CAMCAD. This is due to some inconsistencies we have encountered in Mentor produced Neutral files and the subsequent handling of names to normalize these inconsistencies in CAMCAD. 

Multiple Shape Complex Pad Shapes, Pad layers with multiple shapes

Mentor Neutral files can contain only one shape element for each physical layer in a padstack. In cases where there are multiple shapes for a physical pad layer the Mentor's Neutral file writer will create a rectangular shape to span the X and Y Min and Max extents covered by the shapes.

Pin and Geometry Inconsistent Names

We have seen that, in some Neutral files, the case used for PIN and GEOMETRY name is not consistent. A geometry definition for "SOIC" may exist, however, a component instance of U1 may refer to geometry "soic" which does not violate any rules for the Neutral file format. This information coupled with the knowledge that in Mentor Boardstation it is impossible to have a Pin and a Geometry with the same name resulted in the following rule: 

All names (Pin, Geometry, etc..) from Mentor Neutral are converted to all uppercase when imported into CAMCAD.

This, in and of itself, should cause no problems given the data that lead to the creation of the rule, however, enter a different CAD system into the mix and the potential for problems is extreme. In CAD systems other than Mentor Boardstation it is potentially possible to have a padstack and  a Geometry with the same name whether or not the case is different. If this system then produces a Mentor Neutral file and there is no handling in that export feature to normalize the data consistent to the rules in Mentor Boardstation and this file is loaded into CAMCAD then there will, at a minimum, be errors during the load in CAMCAD and will result in inconsistent or incorrect data. At the worst a Geometry with a name of "A" may contain an instance of a PIN geometry with the same name ("a" or "A" as case is not considered pursuant to the rule above) which would cause and endless loop of inserting the geometry into itself. This scenario will cause CAMCAD to crash.

Layer Names With Spaces

Integra generated neutral files may contain spaces in layernames. This is against Mentor Boardstation rules, and results in potential problems reading information from the file. For example, in this neutral file from Integra, the layer names "Unten Loetseite" and "Oben Bauteilseite" contain a space. This results in incorrect parsing of the data line.

Board Added Parts

Mentor Neutral files may contain information in a Board Added Parts section (B_ADDP). Lines in this section of the neutral file begin with B_ADDP. Geometries that are called out in this section do not have a definition in the geometries section of the neutral file. Therefore, CAMCAD knows something is supposed to appear at that certain X,Y location, but it is never defined what is supposed to go there. This is akin to having undefined apertures in a gerber file - if a D10 is supposed to be flashed at an X,Y location, that doesnt tell us what D10 looks like. It could be a circle, or a square, or a target, or a thermal, or any number of other shapes, of any number of different sizes.

B_ADDP information is placed on individual layers in CAMCAD during import, one layer for each B_ADDP item. CAMCAD will place a generic .100 circle at that location, as we dont know what else to put there, and the entity is classified as UNKNOWN. Users will need to define the geometry type by querying the circle and modifying the TYPE field from UNKNOWN to something else, like FIDUCIAL.