Sunday, May 18, 2008     Register | Login | Search | Contact Us
     
Home
Forums
Subject: pick and place file - metric mils conversion
Posting to forums is available to community members only.
Login or Register
Rate this topic:
   
Author Messages
AhmetOzsoy
Posts: 6
Online: User is Offline
5/09/2008 12:07 AM  
Hi All,


Assume your board is designed with mils setup and you use mils. Is there a method to generate 'metric'  pick and placement report WITHOUT changing the original setup file ( already use mils ). Because the conversion is a mess for the brd file. I takes too long time ( and may convert 24.99 instead of 25- if the accuracy setup is not optimized) and this may result many DRC's in the brd file.

And I wish the the allegro will give metric and mils for the same time in the future. Especially for measuring some distance .

Thanks for the answers.

Ahmet OZSOY
jch teyssier
Posts: 19
Online: User is Offline
5/09/2008 9:53 AM  
For 1MM, what allegro should answer?

39.37007874....... and so on.


Changing unit ans you ALWAYS have roundoff problems

MM to Mils: divide by .0254 : heavy roundoff problems
Mils to MM: multipli by 0.0254: only accuracproblems:

I have chose to work ONLY with MM's
cadpro2k
Posts: 16
Online: User is Offline
5/10/2008 11:53 AM  
I can give you a round-about way, if you don't like to re-specify the database to get the MM pick-n-place.

Out put the X-Y file to excel
Create a formula to make the conversion in excel
Output the file in .txt format

You can then cludge it back into a placement.txt file and import that to a MM database.

If I REALLY felt I needed to do that I would. I would prefer to change the database (setting MM decimals to 2 places) and export from Allegro. I don't see rounding as a real issue now-a-daz. Fab vendors couldn't really care about your accuracy. They care LOTS MORE about fabrication issues (line widths, spacings, impedance, etc.) They can pretty much drill anywhere; they worry about their own fabrication accuracies; and being manufacturable.

Just being me. :)
Mitch
Posting to forums is available to community members only.
Login or Register

Forums > Silicon-package-board > PCB Design > pick and place file - metric mils conversion


ActiveForums 3.6
     
Copyright 2006 Cadence Design Systems, Inc.