Contact US

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Filling in a hole...

Filling in a hole...

Filling in a hole...

I am working on a product design where the product will have one of two PCB designs installed in it.

One of the PCBs has an RJ-45 jack on it, the other doesn't. If the non-RJ-45 PCB is used, there will be a hole at the back of the product that would need to be closed.

Is there an off the shelf PCB mountable product that could close up the hole on the non-RJ-45 version of the PCB?


RE: Filling in a hole...

Some consumer products packaged in a plastic housing have molded-in punch-outs for the connectors. The punch-outs are not punched-out for the unused positions. A really common example might be found in your desk telephone (YMMV). I've seen a telephone with about a half-dozen positions, with only two punched-out and populated. The remaining had only the molded-in breakaway lines showing.

If it has to be a soldered-in component, then perhaps a little custom metal stamping to form a plate blocking the hole.

Next option might be a rectangular plastic plug.

RE: Filling in a hole...

Thanks for the reply.

Yes, the breakaway on the plastic housing, or a knockout on the metal plate are both options as well. Our manufacturing engineers are griping about those options though. They would rather see the difference between the two product versions limited to just a PCB change rather than other parts or configurations... even on the line at point of assembly.

Thanks again!

RE: Filling in a hole...

Solutions I've seen include a plastic label plate that only has the opening when the option is ordered. It will also include the model and serial number and any labels for external connections, knocking out a number of functions with one part. I've also seen snap in covers, which are pretty cheap. Less frequently I've seen a custom molded part that is heat staked from inside the housing, which makes for a very neat solution; I expect the housing are ordered that way from a supplier under a number that is different from the ones without the cover.

I can see where knock-outs are a pain on the production floor. They need to pry out the right one (s) and there's dealing with the little scrap bits and they may not break out cleanly, damaging the housing.

I don't recall ever seeing a blanking part on a circuit board, though nothing is impossible.

RE: Filling in a hole...

Put the jack in both boards.
It's cheaper than any custom part.

Mike Halloran
Pembroke Pines, FL, USA

RE: Filling in a hole...


Put the jack in both boards.

Then add a blanking plug in the unsupported jack. Exactly what the cheapskates at HP do.

Keith Cress
kcress - http://www.flaminsystems.com

RE: Filling in a hole...

I'm putting all of these options on the table at this point in hopes that someone makes the intelligent decision.

Thanks again!


Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members! Already a Member? Login


Low-Volume Rapid Injection Molding With 3D Printed Molds
Learn methods and guidelines for using stereolithography (SLA) 3D printed molds in the injection molding process to lower costs and lead time. Discover how this hybrid manufacturing process enables on-demand mold fabrication to quickly produce small batches of thermoplastic parts. Download Now
Design for Additive Manufacturing (DfAM)
Examine how the principles of DfAM upend many of the long-standing rules around manufacturability - allowing engineers and designers to place a part’s function at the center of their design considerations. Download Now
Taking Control of Engineering Documents
This ebook covers tips for creating and managing workflows, security best practices and protection of intellectual property, Cloud vs. on-premise software solutions, CAD file management, compliance, and more. Download Now

Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close