Electronics > Beginners

Copperclad FR4

<< < (3/4) > >>

KL27x:

--- Quote --- a 1/4"-wide strip has an impedance of something like 10 ohms, great for longer distance gate drives for example.
--- End quote ---

Dunno what you think I'm using. It's 'posedly used for RF shielding and the like. The copper comes in standard thicknesses. I have had it in 1/2 oz and 1 oz pour copper thickness. 0.007" is the total thickness which includes the same copper layer as typical PCB's. I imagine a 1/4" wide track in 1 oz copper would be several meters before you would record 10 ohms?

If you are using high enough voltage, I'm sure you could short across the air gap left by Manhattan islands. I supposed, high enough, and you could arc through the FR-4. Anything low voltage, I imagine would be fine. Around 6 thou clearance "between traces" is not particularly remarkable. I've never had a short or arc.

edit: Oh, you mean impedance of signal propagation due to proximity/capacitance to ground plane? Yeah, I suppose that could be too close/thin for many things. Hot glue or doublestick tape adds some thickness, too, though. I don't know much about high frequency PCB design, how close you can get your layers/pours. To me, 10 Mhz is pretty high. I have never done a manhattan style prototype for speed reasons. Just convenience.

bd139:
Manhattan works fine. Regularly use it up to 150MHz or so RF stuff without resorting to anything special. Can go deadbug as well.

I use 1.6mm stuff for the substrate and then 0.8mm stuff for the traces. The 0.8mm stuff is cut with some decent Fiskars scissors and the 1.6mm stuff with aviation shears. If you really want impedance control, based on the average Er of FR4, cutting 1.5mm strip of 0.8mm thick stuff is around 50 ohms. Loctite superglue is used to glue it.

Here's a pile of crap I have lying around that was done with it. The filter in that is a 70MHz low pass which is the fastest thing there and it has no weird responses up to 520MHz which is as high as I can go with my signal generator



Edit: if you don't want shorts, cut the 0.8mm stuff upside down with one blade of the scissors flat on the bottom blade. That stops the copper getting folded down. Never shorts.

fixit7:
What are those 3 copper coils?

Kalvin:

--- Quote from: fixit7 on May 19, 2019, 12:58:18 pm ---What are those 3 copper coils?

--- End quote ---

Looks like lowpass filter.

bd139:
Yep low pass. 3dB at 70Mhz.

Navigation

[0] Message Index

[#] Next page

[*] Previous page

There was an error while thanking
Thanking...
Go to full version
Powered by SMFPacks Advanced Attachments Uploader Mod