1. Home
  2. Electronics Design
  3. Blob-board for high-freq prototyping

Blob-board for high-freq prototyping

Instead of prototyping "dead bug" on the usual sheet of copper-clad FR4, has anyone tried laying out more "permanent prototypes" of RF circuits where you a) place all your components on a piece of through-hole "blob board" and solder them in place; b) put a blob of solder on all the unused pads and join them together with solder bridges in a grid, then ground the grid, and c) connect up your components on the underside using thin solid-cored jumper wire laid over the grid?

Would the grid work at all well as a ground plane?

Reply to
bitrex
Loading thread data ...

As quick and inexpensive as the proto houses are, I just make a board.

--

Tim Wescott 
Wescott Design Services 
http://www.wescottdesign.com 

I'm looking for work -- see my website!
Reply to
Tim Wescott

Time is of the essence. I like the blob-board idea. John Larkin is certainly our man. He's made so many sheet-style prototype boards, he knows what's needed. Heck, I'll run a CAD program. But he's the boss.

--
 Thanks, 
    - Win
Reply to
Winfield Hill

In general, no.

I prototype live-bug on copperclad (preferably gold plated) FR4.

formatting link

formatting link

formatting link

Of course, there are different definitions of "high-freq". The big cut is whether you need controlled-impedance traces. The big boundary is around a few hundred picoseconds.

I hate dead-bug and wiring on both sides of a proto.

--

John Larkin         Highland Technology, Inc 

lunatic fringe electronics
Reply to
John Larkin

4,
b

how about this:

formatting link

Reply to
Lasse Langwadt Christensen

Sometimes it's nice to be able to hack something together expediently that you can put in a case and use without having to lay out a board and have it made, or have a big "dead bug" ugly mess in a box.

Reply to
bitrex

The question is what kills you first, the parasitics of not having some kind of ground plane, or the limit imposed by your "traces" needing to actually be transmission lines.

Ordinary blob-board has caused me trouble even just in the 10s of MHz.

Reply to
bitrex

I enjoy the occasional dremel-and-solder project. Gets me out of my chair and away from a screen. And I get immediate reinforcement, no waiting for a PCB or anything.

--

John Larkin         Highland Technology, Inc 

lunatic fringe electronics
Reply to
John Larkin

That's pretty cute!

Reply to
bitrex

Jan Pantlje (sp) is/was the master of blob boards.

bitrex, what's RF? 10 MHz? and as Tim says order a pcb. I sometime feel bad at the number of "mistake" pcb's are in my junk drawer.

George H.

Reply to
George Herold

I prefer live-bug as well, most of the time. With dead-bug, I seem to lose track of what I'm doing and end up wiring 40+ pin parts backwards. Fortunately the electrons don't care much about aesthetics, so I skip all the gold plating and hand-carved islands.

Example from last week:

formatting link

As I mentioned on Dave Jones's blog

formatting link
this is what you get to do when you buy an X-ray machine on eBay but don't get the PC that was supposed to come with it...

-- john, KE5FX

Reply to
John Miles, KE5FX

Somewhat, I expect.

You can get pad-per-hole board with a ground grid

--
This email has not been checked by half-arsed antivirus software
Reply to
Jasen Betts

Hey, it's an art form.

--

John Larkin         Highland Technology, Inc 

lunatic fringe electronics
Reply to
John Larkin

A grid acts fairly well as a ground or power plane; wire/line/trace spacing will determine frequency characteristics.

Reply to
Robert Baer

Hey, are you Algernon?

Reply to
Robert Baer

When doing dead bug, I use dikes to gouge a notch on the pin-1 end of the package, so I can see what I'm doing. I very rarely get things backwards since I started doing that.

Live bug weakens the pins too much--I like to be able to really reef on them while twisting resistor leads, for instance. The nice robust standoffs you get 14-to-a-package are one of the big advantages of dead bug. It's also faster.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs 
Principal Consultant 
ElectroOptical Innovations LLC 
Optics, Electro-optics, Photonics, Analog Electronics 

160 North State Road #203 
Briarcliff Manor NY 10510 

hobbs at electrooptical dot net 
http://electrooptical.net
Reply to
Phil Hobbs

Huh good idea. Even with live bug, I find it hard to find pin 1 sometimes. (Soic... just some dang flat on one side.) And I'll mark it with dot from a silver Sharpie (permanent marker pen)

George H.

Reply to
George Herold

One more vote for this.

--

-TV
Reply to
Tauno Voipio

I haven't handled a DIP packaged IC in years. I use adapters.

formatting link

formatting link

One nice thing about adapters is that it becomes easy to replace a part, to try something else or because you blew one up.

--

John Larkin         Highland Technology, Inc 

lunatic fringe electronics
Reply to
John Larkin

So do I, when I'm just building something for testing. However, I often prototype whole instruments, much of which can be done with DIPs and TO92s. This one is a lock-in amp, adjustable temperature controller, and two switching supplies with cap multipliers. Took about half a day to build, iirc.

formatting link

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs 
Principal Consultant 
ElectroOptical Innovations LLC 
Optics, Electro-optics, Photonics, Analog Electronics 

160 North State Road #203 
Briarcliff Manor NY 10510 

hobbs at electrooptical dot net 
http://electrooptical.net
Reply to
Phil Hobbs

ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.