[Caleb] needed to use some surface mount components when prototyping. Instead of buy a breakout board he made one himself without doing any etching. The process he shows off in the video after the break uses copper tape to layout the traces for the board. It’s quite an interesting method which requires a sharp knife and a steady hand.
He used regular protoboard as a substrate and applied a layer of copper tape on the side without copper pads. From there he poked holes for the DIP pin headers. Now it’s time to do some cutting. [Caleb] removed the band of copper that would fall in between the pins of the surface mount device. He then tacked it in place with one dot of solder and drew the traces from the part to the pin headers. After removing the part he cut out the waste in between each line he drew with marker. What he’s left with is a set of thin traces that connect each pin of the surface mount component to the corresponding through-hole pin header.
This is very time-consuming, but then again so is soldering jumper wires to small-pitch components.
[youtube=http://www.youtube.com/watch?v=dLBB1r3jWoI&w=470]
This is cool, but I guess I’ll share something I did to solve the same problem.
I needed a breakout for the same module in the article picture (a Hope RF RFM12B), and Sparkfun wasn’t delivering on their promise. I wouldn’t have come up with this method on my own either way, but my hands are NOT steady enough for this.
I bought a spool of wire-wrap wire (30AWG, I believe) and cut a bunch of ~1″ pieces. I then stripped a little bit off the end.
I applied some solder to all of the solder cups on the module and proceeded to solder a piece of wire to each pad.
I put some double-sided foam tape on the back of the module and attached it to the board.
Then I soldered some pin headers to the board and soldered the other end of the wire-wrap wires to the soldering side of the pin headers. I was lazy and just worked at it until I was able to melt through the insulation of the wire, and then cut off the excess.
I soldered on a wire whip antenna, and away I went. I’ll send HAD a picture if it would be useful. This wouldn’t work for large QFP or TSSOP packages (!@#% QFN), but it worked in this case.
This is truly another dimension to ghetto-electronics and a certainly good one, but that copper tape costs some money and I would be happy to see someone doing that very same thing with, say, aluminium foil, the soldering-under-cream-technique :>
Wow, this is a extremely useful and clever trick. I am gonna have to try this out on some of the SMD samples I have laying around.
Not the same Scott here…
I might be missing something, but isn’t this just using tape to provide pads for the breakout headers, which connect to the pads on the mini-board?
In other words, you could skip the copper tape and the cutting, and just use solder-tipped wire?
I’m not passing any judgement, to each their own, but it seems that thin wire would be lots lots faster, cheaper, and less error prone… unless I am missing something. -grin-
@Scott #2
Glad another Scott agrees with me.
It at least makes good sense for this particular device, and traces on smaller devices would be impossible to make by hand. I’ll get that picture tonight.
In retrospect, I’d use thicker wire for the ground and power, if possible. I liked the wire wrap wire because it could pass through the through-holes in the radioshack protoboard.
I refresh hackaday at work when I’m bored.
you could always do insane things like that:
http://elm-chan.org/docs/wire/wiring_e.html
Scott #3 here! Perf board drives me nuts, and isn’t wonderful for RF. While this application is fine, keep in mind that higher frequency applications might desire a prototyping technique utilizing a large ground plane. I shamelessly provide examples on http://www.swharden.com/ ^_^
That sticky copper tape is cool! Could you stick it to a piece of plastic and cut out lines, to make a PCB-style circuit? That tape can be un-stuck and re-stuck, and isn’t quite as permanent as my method http://www.swharden.com/blog/images/IMG_5261-525×393.jpg so thanks for the hack!
–Scott #3
Do the same thing soldering some cat-5 wire to the solder cups and sticking the wires into the breadboard.
Yeah, no offense, but I’ve been doing this without copper tape, using only wire-wrap wire, for decades. The copper tape is not necessary. For the real small stuff, like a QFN package, glue the chip upside down and use your magnifier to solder the small-guage wire-wrap wire to the pins. Way faster than trying to design and etch your own breakout board.
What I want is a solution that will let me easily breakout a 2mm x 3mm x 0.75mm leadless DFN package.
I understand technology moves on and stuff gets smaller – and skills need to adapt – but I don’t understand why a lot of SMD uses proprietary, socketless design. The Linear LTC3539 comes to mind (awesome chip, but not friendly)
(And By socket, I do not mean DIP.. I mean there’s lots of leadless SMD – processors usually – that would plug into a socket of some sort).
@Scotts:
I do it the same way, most recently for an RN41. needle-soldered a bunch of 1″ wire tails onto the pins, and double-sided-foam-taped the unit to a piece of perfboard.
lay some pin headers along the edges, then just pull each wire to the appropriate pin and solder. i skipped the insulated wire due to size (i used bare 22ga wire) but ended up coating the pins/solder in liquid electrical tape.
works beautifully to this day, even having inserted/removed things a bunch of times from the breadboard.
@cpmike
Glad my method is logical. I came up with it on my own out of necessity. Later in the project I bought the dangerous materials for etching my own board, but this is still faster. This was all for my senior project in college.
Insulated 22AWG wire is large, but you can use 30AWG insulated wire wrap wire for most things. You can actually pass the wire AND it’s insulation through the through-holes.
I will personally stay away from QFNs for hobby projects for as long as possible.
Using a magnifier for QFN packs?? Man, I don’t want to get old…
@smoker_dave,
http://theworldsbestever.com/blog/wp-content/uploads/2010/08/pedo-bear-cake.jpg
I remember using a mechanical pencil (side button type) with a reel of fine wire from a solenoid on top.
That way I could hold the wire with the pencil while soldering. When done you press the button and pull to feed. Spots of cyanoacrylate holds the wire on the board if need be.
Very quick to hack traces on a beta board.
lol didnt see the one above linked above. Same idea with pictures :).
Is Circuit Sealer (conductive pen “ink”) viable for no-etch connections? Possibly with masking..
Not necessarily what method is “better”, but wondering if CS is practical, and if the resulting trace is stable (or will it deteriorate over time)?
Conductive ink works pretty well, and even better when heat treated. However, it has no real adhesive properties, so you still have to solder the chip and any passives to something.
Here are the pictures I promised.
http://i.imgur.com/RXFT1.jpg
I botched that last post… wasn’t paying attention.
http://imgur.com/a/sAu33#R6Fzu
@ Scott
That looks really good. I love seeing what other guys are doing.
@ Slander
Do you have any pictures of projects you’ve done using conductive ink you can share?
dont invent weak ways, get rotary tool
@ Caleb
The only projects I did with it have now been dismantled, unfortunately. I can, however, explain more:
To clarify, the product I used was CircuitWriter. Circuit Sealer, as I just looked it up, is a conformal coating pen made by the same company.
My project was to draw an LED array onto a door, using the ink to bond the LEDs as well (and using a coating over some trace to allow traces to cross each other). Once I solved the problem of the solvents dissolving the paint on the door, it actually worked pretty well. Resistance was low, and could have been lower with heat treating (I just used hot air, as I couldn’t heat treat a door).
While the ink was okay at bonding to static components, any movement between the two, even after drying, would instantly break the bond. The SMT LEDs had to be superglued to the surface first, and then have the ink applied. Connecting wires to the traces was rather hard as well. It might have been easier with smaller wire, but it was nearly impossible to form a lasting connection. The solution I eventually found was (accidentally) mixing some of the ink with a clear silicone adhesive/sealant (I think it might’ve been for fishtanks and stuff), which somehow maintained conductivity, albeit not as well. It was only later that I realized they sell conductive epoxy.
But, yeah, circuit writer is great for making traces, but it is extremely hard to control the width–I couldn’t reliably make thin traces, only really big ones. However,it might be possible to combine the pen with a mask cut from some sort of plastic to make better traces (although, for anything but small fixes, it’s a lot of hassle for little reward).