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cutter.
for
That's what I do too. Here are my latest prototypes
Black and red ones are for work, blue ones are for hobby stuff I piggy backed on the job :)
It was about $45 incremental cost for each extra panel.
How would you cut the width precise enough for a stripline? (Measure the results?)
Would seem better to use two-sided sheets, too. Controlling its behavior would seem easier that way than glueing single sided to another sheet below.
Sounds worth trying though.
Jon
But that forces you to plan ahead!
on the squares?
30 mil FR4 is about 30 pF per square inch, so the small pucks are roughly 1 pF. On this particular board the fastest thing is a 1 MHz Butterworth filter and the smallest cap there is 1.8 nF, so I'm OK.I've done picosecond stuff by carving FR4 into matched-impedance traces, but I thought I'd try something different this time.
Here's a power supply done in copper-hack mode:
cutter.
nickel
and
for
Pretty.
One of my customers decided to make their own boards red to flag the ones that were especially ESD sensitive. QC heard about it, so all their boards are red now.
I only needed one as a proof of principle, but the customer wanted it essentially overnight. We'd normally do a PCB layout for stuff like this, maybe toss in a couple of other circuits or adapters or something, but that would take a week or so.
Can't argue with logic like that.
Show us something you've prototyped lately.
--
John Larkin Highland Technology, Inc
jlarkin at highlandtechnology dot com
Precision electronic instrumentation Picosecond-resolution Digital Delay and Pulse generators Custom laser drivers and controllers Photonics and fiberoptic TTL data links VME thermocouple, LVDT, synchro acquisition and simulation
At least temporarily, it is on display at the Computer History Museum in Palo Alto (I think that's the right city, but they moved since I last visited (too long ago)).
Jon
A simple test prototype:
It uses stripline FR4 that has peeloff tape so it is glued onto the base FR4
Those were sold by a danish company, but last year they stopped selling them. I have a new supplier with equal parts, will post it here when I remember the name...
Regards
Klaus
I have a new supplier with equal parts, will post it here when I remember the name...
Found it:
(all kind of pads, including SOT-23 pads, SO14 etc)
Regards
Klaus
Not so hard with a ruler and some concentration, of course, that depends how precise you need the impedance. I'd guess 10% isn't too hard.
Tim
Back in the early 90's when I was taking microwave circuits, they had the big X-Y table with a cutting head. You put a DULL xacto blade in it, and you used it to scribe you line to one mill accuracy. Then, you cut it out with a sharp xacto knife. We used single sided rogers material which you then covered with wide copper tape and cut away all the extra material...
Shear it a little wide and sand it down to size. You could even sand it down to frequency.
Just put some sandpaper down on a table and rub the little microstrip sliver over it.
Right.
Nicely done.
I built low frequency prototypes using little FR4 squares attacked with cyanoacrylate adhesive. For single sided 0.062" boards, a window glass cutter was used to score the side without copper, which could then be "cracked" into a long strip. I would then cross cut as needed. The problem is that the long strips tended to curl and refused to lie flat. So, I dragged a few blank panels to the local PCB shop, and had them run it through their "v" scoring cutter at various widths, shapes, and sizes. Mostly, I wanted small pads, varying from 0.2x0.2 to about 0.75x0.75 inches. To "crack" the panels, I used sheet metal brake. I don't recall how many I had them make, but it was enough to supply 3 engineers over about a 7 year period with prototype pads.
Today, I'm less elegant. I have a 10" chop saw that pretends it's a radial arm saw. I insert a carbide rip blade (no offset on the teeth), tilt the saw to 45 degrees so that it makes a "v" cut, and score some PCB panels. It's cheap, elegant, convenient, reliable, but dangerous. Be sure to clamp the PCB material, and don't put yourself where a flying PCB might carve a new navel.
When I'm feeling less dangerous, I have another prototype method. Take a single sided 0.062 PCB, and cover the copper side with insulating, sticky back, vinyl window shelf paper. Take a roll of sticky back copper, commonly used for stained glass windows, and make pads with a pair of scissors. Stick the pads where needed on top of the vinyl. Where ground is needed, use an exacto knife to remove the vinyl and expose the underlying copper. This is not as strong as using PCB material, but it's quick and easy. Excessive soldering iron heat will melt through the vinyl, so work quickly.
Only if the prototype works.
Absolutely not. If you are making the board for yourself, and you NEVER make mistrakes, and know you will need only ONE (say for a year), the Xacto method is fine. In all other cases, the plan is for 2 or more --> paper negative time at minimum.
I plan to prototype my plan of prototyping..
Hi Jon, Do you have a copy of the second Jim Williams book? There's an article on prototyping and circuit layout. Near the end the author talks about a "Wainwright mini mount system"... Never used it and it may not even still be in production.
George H.
Hey, here's a copy of the same article.... by James Bryant.
Enjoy,
George H.
These are great:
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