×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

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

1/2 oz vs 1 oz copper

1/2 oz vs 1 oz copper

1/2 oz vs 1 oz copper

(OP)
Hi,
When etching microstrip antennas the board material is available in 1/2 oz vs 1 oz. Why do I choose one over the other? Thanks

RE: 1/2 oz vs 1 oz copper

(OP)
I should say 1/2 oz copper clad vs 1 oz copper clad. There is also rolled vs electrodeposited, which I know affects the surface roughness and maybe loss/glue adhesion. Other things I should be aware of?

RE: 1/2 oz vs 1 oz copper

Thickness of the copper will affect your impedance.  Agilent's AppCAD freeware is useful for calculating the impedance of microstrip.

RE: 1/2 oz vs 1 oz copper

Well, for one thing the different thicknesses change the strip dimensions, which can have a minor or major effect on your antenna specs, depending upon frequency of interest, bandwidth, etc.  Pretty much every standard type of board is going to be rolled... why do you care about the construction process?

Dan - Owner
http://www.Hi-TecDesigns.com

RE: 1/2 oz vs 1 oz copper

(OP)
The thickness of the copper only (not the board), at least near 1 GHz, doesn't have a huge affect on the line impedance. I went straight to the Rogers website and used their calculator for microstrip line and it only made ~1 ohm change. The actual board thickness of course makes a big difference. There is a current carrying capacity which changes with copper thickness, but it didn't seem to make a big difference in power handling...

RE: 1/2 oz vs 1 oz copper

The primary reason for thinner copper is to etch thinner lines.
Say you want to etch 2 mil lines and your copper is 1.4 mils thick, there's alot of undercut in the etching process for that case. Your impedance will be inconsistent for thin lines in that case, and pretty good for wider lines.

For most patch antennas, 0.5 vs. 1 oz copper isn't too much of a difference.

electrodeposited cracks easier with vibe and cold, but etches cleaner and more accurately.

If you have a large patch array or interferemeter array at 18-40  ghz and use rolled copper, when the copper is etched away, your circuit board physically shrinks (or springs back) with rolled copper since the rolling of copper onto dielectric board (with heat) stretches the base dieletcric. You actually have to make artwork larger in dimension than you want to plan on the shrinkback.

Read Rogers corp. info for more details.

kch
khiggins@toyon.com

RE: 1/2 oz vs 1 oz copper

You would use the 1oz copper if you were working with higher power RF antennas.  For standard microstrip work, 1/2 oz is used, as stated above, since it is easier to control the etch widths of.

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


Resources

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