Who's down for some SMD layouts?

Barry

Well-known member
Solder paste without a stencil makes me want to just start buying pedals.... or just become a drummer.



The kind of circuits I have in mind don't have too many germanium components.
Wasn't quite that bad, I think Transitors will be easier as the legs aren't so close, future I'll probably just use it to set the corners on chips
 

PedalPCB

Admin (Robert)
Staff member
5150 build Robert?

Well, we gotta finish tracing it first... I've been working on it for about a year now. :ROFLMAO:

Every couple weeks I glance over at it then trace another Tube Screamer instead.

I actually picked it up to take a photo today, so that's progress. It's not so much the complexity of tracing it that I dread, it's the realization that this circuit is not going to fit into a reasonable sized enclosure with through-hole components.
 
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Stickman393

Well-known member
Keep em in the tape reel and that's not an issue, although removing them from the tape is probably the most time consuming part of assembly.

You can use whatever you want... I will say, I built a prototype for an overdrive this weekend that used nasty old ceramic disc capacitors throughout the entire signal path. (330pF all the way up to 1uF) I could have used film, I suppose, but the original used ceramic so that's what I used... It has become my favorite overdrive.

I'm not arguing the theory against ceramics, but I'm also not convinced that the hate is entirely based on objective audible results (vs what I read on a forum) in every case... this ain't HiFi. Don't mind me though, I generally don't modify or "fix" the quirks with original circuits either unless it's obviously broken in an unusable way.

Of course there's no reason we can't mix in some through-hole caps when absolutely necessary. The goal here isn't to torture your soldering skills (or supernaturally sensitive ears), the goal is to cram 10lbs of s**t into a 1/2lb enclosure. :D
For sure...I'm the kind of guy that measures out ingredients to precise ratios when cooking whilst having all available counter space occupied by dirty dishes and oh shit my 1/3 cup has gotta be around here somewhere WHY IS COOKING SO HARD.

Only thing about ceramics that makes me weary, though, is temp coefficient on non-C0G. Some of those...shit gets wild. Not a problem in power supply filtering...but tone stacks?

Though, clearly, germanium suffers from this same issue. Personally, I've never fallen in love with a Ge fuzz. I like my chaos to be consistently...erm...

Huh. Walked right into that oxymoron. Whelp, I stand by it.
 

jubal81

Well-known member
I'm pretty happy with my SMD system I've cooked up. Amazon has a lot of tool and gadgets for 'beading' and it's pretty perfect for SMD parts.
Removing each one from the strip is the longest part, so I got little beading cups with screw-on lids. I pull the whole strip of parts into the cup at once.
When I need a part, I tip the cup over into a tray with a little funnel on it, so when I'm done with that part, I can just funnel the SMD parts back into the cup.
Another great tool I made is a combination tweezers and 'helping hands' part holder. I got some reverse tweezers (closed by default, squeeze to open) and used my laser to cut some plastic discs (one with a notch) to make a 'base' to hold the tweezers in an upright position and apply downward force on the part it's hold to help keep it in place while I solder.
I use some magnifying visors, but those microscopes are getting really cheap and probably my next purchase.

IMG-1155.jpg

IMG-1156.jpg

IMG-1158.jpg
 

PedalPCB

Admin (Robert)
Staff member
I’d be up for it for sure! But It would have to be the right project. I mean I wouldn’t want to do a full smd board that’s just a Tube screamer or 250+.

Absolutely, I have no intentions of making a project SMD just for the sake of being SMD... The decision would be based on circuit complexity and/or enclosure size constraints.

With that said, I'm thinking the first SMD project will likely be an adaption of one of the basic overdrives as a sort of "Introduction to SMD assembly" for the beginners. Slightly oversized board with healthy spacing and a variety of common components... rather than throw folks into a Low Tide for their first SMD experience. :ROFLMAO:
 

fig

Village Idiot
I've noticed the hot air station also has a bit of a learning curve, but as mentioned with other methods it mostly is due to too much / too little / improperly placed solder paste. Solder bridges seem to be given, but the fewer the better.

Anyone have a recommend for stencils? I've seen quite a spread so any direction is appreciated.
 

PedalPCB

Admin (Robert)
Staff member
Anyone have a recommend for stencils? I've seen quite a spread so any direction is appreciated.
The easiest way is a stencil that is designed specifically for the PCB you're working with. (although not the most economical for one-offs)

I should have a generic FV-1 IC stencil made though, that's one application that would definitely benefit.
 

JamieJ

Well-known member
I’ve never soldered an SMD resistor or capacitor but I’m assuming 0805 will be absolutely no problem and 0603 are a challenge but do able with the hand soldering approach?
 

jubal81

Well-known member
I’ve never soldered an SMD resistor or capacitor but I’m assuming 0805 will be absolutely no problem and 0603 are a challenge but do able with the hand soldering approach?
I stick to 0805 on my layouts and 0204 for MELF resistors. 0603 is getting into my PIA zone.
SMA-A_series_SPL.jpg
 

fig

Village Idiot
I stick to 0805 on my layouts and 0204 for MELF resistors. 0603 is getting into my PIA zone.
SMA-A_series_SPL.jpg
Here's a little practice board. I just soldered these 0805s. The first one I used paste on a cold board and preset the resistor. The second, I used a cold board, pre-placed the resistor and used small diameter solder. The last, I pre-warmed the board, dabbed paste on the pads (much easier when it softens into the warm pad) and placed the resistor...then reheated the board to fuse. Really easy.

FrzAI7v.jpg
 

jubal81

Well-known member
Here's a little practice board. I just soldered these 0805s. The first one I used paste on a cold board and preset the resistor. The second, I used a cold board, pre-placed the resistor and used small diameter solder. The last, I pre-warmed the board, dabbed paste on the pads (much easier when it softens into the warm pad) and placed the resistor...then reheated the board to fuse. Really easy.

FrzAI7v.jpg

Nice!
You do that all with the little hot plate? You also use a hot air gun on top? Gotta link to paste?
 
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