Home > Community > Forums > IC Packaging and SiP Design > Single layer boards

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: *

 Single layer boards 

Last post Tue, Nov 11 2008 1:18 PM by labrat7. 10 replies.
Started by labrat7 11 Nov 2008 10:02 AM. Topic has 10 replies and 6521 views
Page 1 of 1 (11 items)
Sort Posts:
  • Tue, Nov 11 2008 10:02 AM

    • labrat7
    • Not Ranked
    • Joined on Tue, Nov 11 2008
    • Posts 7
    • Points 95
    Single layer boards Reply

    Has anyone done anything with single layer flexible cirtuit boards?

    I am having trouble finding out how to define the cross section for only one layer. The layout cross section window says I can't delete either the TOP layer or the BOTTOM layer.

    The board I am designing has pads on both sides of a single layer of conductive material.

    Any help would be appreciated.

    • Post Points: 35
  • Tue, Nov 11 2008 10:43 AM

    • Tyler
    • Top 500 Contributor
    • Joined on Thu, Jul 17 2008
    • Tempe, AZ
    • Posts 33
    • Points 480
    Re: Single layer boards Reply

    The tool does require you to have at least the two layers in your design. This is because it assumes that you would need different layers to represent the top versus the bottom side of the physical substrate.

    You stated that your design has pads on both the top and bottom sides of the layer. Assuming your conductor traces are on a layer "M1", what layer would the top and bottom pads go on, relative to M1? Would these need to be on separate layers so that the tool can effectively DRC the bottom pads against each other and separate from the top pads?

    Based on that, we might be able to offer some reasonable solution(s) that will be understood by the other parts of the system.

    • Post Points: 20
  • Tue, Nov 11 2008 10:48 AM

    • Alexandra
    • Top 500 Contributor
    • Joined on Wed, Sep 17 2008
    • Posts 30
    • Points 405
    Re: Single layer boards Reply

    "pads on both sides of a single layer" is a bit confusing.

    Do you have component pads and routing only on one layer (top)?

    If yes, consider a two layer board and send only the top layer GBR.

    If you have at least a via, it is a two layer board.

     

    • Post Points: 20
  • Tue, Nov 11 2008 11:00 AM

    • labrat7
    • Not Ranked
    • Joined on Tue, Nov 11 2008
    • Posts 7
    • Points 95
    RE: Single layer boards Reply
    The circuit board is a flexible design using polyimide film as the board material. The “M1” layer has 3 copper traces ½” wide running the length. The pads on each end need to be open on the bottom while the 2 sets of pads near the center need to be on top.

    See the attached bitmap.
    • Post Points: 5
  • Tue, Nov 11 2008 11:04 AM

    • labrat7
    • Not Ranked
    • Joined on Tue, Nov 11 2008
    • Posts 7
    • Points 95
    RE: Single layer boards Reply
    The board is a flexible board using only Polyimide insulating material and copper.

    Components J1 & J2 need to be facing the bottom while U1 & U2 need to be facing towards the top.

    This is a high voltage, high current pulse design and vias would add too much inductive loading.

    See attached bitmap.
    • Post Points: 5
  • Tue, Nov 11 2008 11:42 AM

    • labrat7
    • Not Ranked
    • Joined on Tue, Nov 11 2008
    • Posts 7
    • Points 95
    Re: RE: Single layer boards Reply
    Okay, silly me! I thought I was emailing directly to you two and attached a bitmap so you could see my problem. I guess you didn't get those...

    I have a 0.5" square at each end of a 7 inch flexible circuit board. Assuming 0,0 is on the lower left corner, about an inch to the right of the first o.5" pad is a pair of 0.1" wide by 0.4" high pads, the left one connected to the half inch pad to its left and the right one connected to the left pad a second set of pods. The right pad on this second set of pads is connected to the 0.5" pad on the righ side of the board. I am using 0.5" wide copper pours to connect this together.

    Since the Polyimide material acts as both the board material and the soldermask, I need the soldermask on the end pads to be on the bottom while the pads in the top.

    I have tried to draw the polyimide material, with the cutouts in the polyimide material below. The P's represent the polyimide material. The spaces represent gaps in the material and the C's lines represent the copper pours.

    PPPPPPPPP   PPPPPP   PPPPPP   PPPPPPP   PPPPPPPPPPPPPPPPPPPPPPPPPP
     CCCCCCCCCC    CCCCCCCCCCCC     CCCCCCCCCCCCCCCCCCCCCCCC
    PPP     PPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPP    PPP

    Does this make any sense?
    • Post Points: 20
  • Tue, Nov 11 2008 11:57 AM

    • Tyler
    • Top 500 Contributor
    • Joined on Thu, Jul 17 2008
    • Tempe, AZ
    • Posts 33
    • Points 480
    RE: Single layer boards Reply

    I think that helps me understand some, yes, though I apologize if I have misinterpreted.

    Are you therefore trying to place J1 and J2 (the comps on the outside with pads on the bottom) mirrored on the board, so that their soldermask pads are correctly on the bottom side? This would cause their conductor pads to be on the wrong layer, as they get mirrored to the bottom layer from the top. Therefore, removing that extra conductor would make the pads stay on the correct conductor layer? 

    If that is the case, you have two solutions to get the pads on the correct side. You can either edit the pad definitions for these components, so that their unmirrored pad is on the bottom layer (which will then, placed mirrored, put it on the top layer) or you can mirror these with the edit->mirror command in mirror geometry mode and update the soldermask layer pads in the their padstack definition to be on the bottom soldermask layer.

    Should you so desire, you could set the material thickness of the unused dielectric and conductor layer to 0, just so that the overall thickness of the design is more accurate. 

    • Post Points: 20
  • Tue, Nov 11 2008 12:06 PM

    • labrat7
    • Not Ranked
    • Joined on Tue, Nov 11 2008
    • Posts 7
    • Points 95
    Re: RE: Single layer boards Reply

    I fear my communication skills suffer when I get frustrated. And this board is driving me nuts!

    I think I'll try mirroring the soldermask only and see what kind of fits I can give the DRC.

    Thanks!

    • Post Points: 5
  • Tue, Nov 11 2008 12:56 PM

    • labrat7
    • Not Ranked
    • Joined on Tue, Nov 11 2008
    • Posts 7
    • Points 95
    Re: RE: Single layer boards Reply

    PCB Editor choked on it and kicks me out everytime I try to mirror just the soldermask!

    Any other thought\ideas?

    • Post Points: 20
  • Tue, Nov 11 2008 1:01 PM

    • Tyler
    • Top 500 Contributor
    • Joined on Thu, Jul 17 2008
    • Tempe, AZ
    • Posts 33
    • Points 480
    Re: RE: Single layer boards Reply

    Are you trying to edit the soldermask directly? Or are you editing the padstack definition's soldermask pad (tools->padstack->modify design padstack)? If the soldermask is part of the padstack, you must edit it through this interface; you cannot directly edit it within the database as a shape. 

    Sorry; this is one of those problems where being able to see the actual database is usually helpful to guide someone in the right direction. 

    • Post Points: 20
  • Tue, Nov 11 2008 1:18 PM

    • labrat7
    • Not Ranked
    • Joined on Tue, Nov 11 2008
    • Posts 7
    • Points 95
    Re: RE: Single layer boards Reply

    I tried to update the padstack then update to the design and that's when it chokes.

    I suppose, since it only for testing purposes, I could email it to you.

    I'll send you an email through here with my contact info.

    • Post Points: 5
Page 1 of 1 (11 items)
Sort Posts:
Started by labrat7 at 11 Nov 2008 10:02 AM. Topic has 10 replies.