Home > Community > Forums > PCB Design > What is meant by Acid Trap?

Email

* Required Fields

Recipients email * (separate multiple addresses with commas)

Your name *

Your email *

Message *

Contact Us

* Required Fields
First Name *

Last Name *

Email *

Company / Institution *

Comments: *

 What is meant by Acid Trap? 

Last post Wed, Jul 22 2009 12:03 PM by Easton. 6 replies.
Started by girish 03 Feb 2009 05:04 AM. Topic has 6 replies and 12997 views
Page 1 of 1 (7 items)
Sort Posts:
  • Tue, Feb 3 2009 5:04 AM

    • girish
    • Top 25 Contributor
    • Joined on Wed, Jul 16 2008
    • Bangalore, Karnataka
    • Posts 241
    • Points 4,920
    What is meant by Acid Trap? Reply
    Hi, What is meant by Acid Trap? how can be avoided? Regards,Girish
    • Post Points: 20
  • Tue, Feb 3 2009 6:21 AM

    • steve
    • Top 10 Contributor
    • Joined on Fri, Jul 18 2008
    • Woking, Surrey
    • Posts 1,181
    • Points 19,215
    Re: What is meant by Acid Trap? Reply

    Acid Traps are generated when a gap from pad to trace is too small. They can be avoided by increasing the gap or moving the trace so that it exits the pad lower down the pad. Or you can use a gloss command to add a fillet from the pad exit.

    • Post Points: 20
  • Tue, Feb 3 2009 7:02 PM

    • girish
    • Top 25 Contributor
    • Joined on Wed, Jul 16 2008
    • Bangalore, Karnataka
    • Posts 241
    • Points 4,920
    Re: What is meant by Acid Trap? Reply

    Thanks Steve ,

    Could you please show any example & how to use Gloss command allegro designL 16 ver supports this?

     

    Regards,

    Girish Kumar

    • Post Points: 20
  • Wed, Feb 4 2009 1:29 AM

    • steve
    • Top 10 Contributor
    • Joined on Fri, Jul 18 2008
    • Woking, Surrey
    • Posts 1,181
    • Points 19,215
    Re: What is meant by Acid Trap? Reply

    Girish

    Screenshot attached. I'm afraid you'll need Allegro Performance and above to do this with Gloss.

    HTH

    Steve

     


    • Post Points: 20
  • Sat, Feb 14 2009 12:48 AM

    • C Shiva
    • Top 50 Contributor
    • Joined on Tue, Jul 15 2008
    • Bangalore, Karnataka
    • Posts 167
    • Points 3,465
    Re: What is meant by Acid Trap? Reply

      Steve,

      What's the problem from these acid traps? Can it be changed the signal shape? I also faced same problem. Please help.

     Regards,

     Shiva.

    • Post Points: 20
  • Fri, Feb 20 2009 8:05 PM

    • pakistan
    • Top 75 Contributor
    • Joined on Sat, Jan 24 2009
    • Posts 78
    • Points 1,200
    Re: What is meant by Acid Trap? Reply

    During cleaning of board chemicals may deposite there. thats why we have to route straight to minimize the probability.

    • Post Points: 20
  • Wed, Jul 22 2009 12:03 PM

    • Easton
    • Not Ranked
    • Joined on Tue, Jul 21 2009
    • Locust Valley, NY
    • Posts 1
    • Points 5
    Re: What is meant by Acid Trap? Reply

    Hi,

    Acid trap always occur on every PCB boards especially high density PCB's.This may result to a short circuit due to the un-etched copper.

    Here are some rules to avoid this

    1.minimize using trace connection less than 45deg vertex.

    2.always remove those isolated plane island

    3.minimize goup vias with a less spacing surrounded by traces

    4.add some via holes to the area were your acid trap located so the chemical can escape thru the other side

     But believe me as far as i know there is no such design that free from acid trap especially multilayer boards.There is no specs define for this.

    Hope this can helps.

    • Post Points: 5
Page 1 of 1 (7 items)
Sort Posts:
Started by girish at 03 Feb 2009 05:04 AM. Topic has 6 replies.