Stats

  • State Not Answered
  • Replies 2
  • Subscribers 161
  • Views 8841
  • Members are here 0
More Content

Problem with a footprint I have in my library

Neil mustafa

Hello all,

I have a problem with my SOT-23 package footprint that I would love to fix but I need some guidance. So, when I place the component nothing seems to be out of the ordinary. Here is a picture of the placed component:

Now, after sending the gerber files for the manufacturing house. I got the following complaints:

- The footprint does not have any pads on the paste layer, doesn’t have a silkscreen box around it, and the pads themselves are basically the size of the pins so there is no room for heel or toe filets.  It would benefit all of us if the layout person could find this suspect SOT-23 footprint and nuke it from your library so that we won’t have this issue again.

- VR1 & VR2 did not have the apertures cut in the stencil. 

- Also, the pads are barely big enough for the leads and probably won't have a very good heel or toe filet. This seems to be a Luminator design problem specific to SOT23's.

Having a second look of the gerbers I sent out , I do see issues. Here is a snapshot of the Gerbers with the addressed components (VR1 and VR2 Marked)

The pictures are inverted due to it being on the bottom side but hopefully with the arrows you get what I'm talking about. How can I make these changes? 

I was able to locate the file where the SOT32.DRA, here is a screenshot of that:

Your help would be highly appreciated. Thanks in advance.

Neil Mustafa.

Parents
  • 0

    In the dra file you need to draw lines (with a thickness) on Package Geometry / Silkscreen_Top which will sort the silkscreen missing out. For the pastmask and pad size (if the name of the padstack is related to the actual size) you can try a Tools - Padstack - Replace and replace the existing padstacks with some that are a more suitable size. If the name doesn't matter try Tools - Padstack - Modify Design Padstack, click on one of the pins then right click - Edit. On the Design Layers tab edit the size of the pin to the required size, on the mask layers tab adjust the soldermask_top and pastemask_top to suit. Save the pad to the Library (padpath location). Then use File - Update to design and exit which will update the dra file with the new sizes. 

  • 0 in reply to steve

    what is the role of apertures. I do see some designs assigned with apertures and some not. Is it necessary for all designs to have aperatures

Reply Children
No Data
Cadence Guidelines

Community Guidelines

The Cadence Design Communities support Cadence users and technologists interacting to exchange ideas, news, technical information, and best practices to solve problems and get the most from Cadence technology. The community is open to everyone, and to provide the most value, we require participants to follow our Community Guidelines that facilitate a quality exchange of ideas and information. By accessing, contributing, using or downloading any materials from the site, you agree to be bound by the full Community Guidelines.