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SMD prototyping techniques -- looking for advice
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Miti:
a) I always design the board and order it at www.pcbway.com. At $5 for 10 pcs plus shipping you can't go wrong.
b) For hand solder, I don't recommend going smaller than 0603. In the oven, 0402 is possible.
c) I only hand solder the boards with very little parts count. You can order a cheap stencil together with the board. I love my toaster oven.
d) Yes, forget TH. Dive into SMD and never look back.
tggzzz:

--- Quote from: ebastler on July 27, 2019, 08:25:03 pm ---Surprisingly, no votes for dedicated SMD protoboards, unless I overlooked something. That's great information -- exactly the kind of practical feedback I was hoping for.

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See the very usable techniques in https://entertaininghacks.wordpress.com/2020/07/22/prototyping-circuits-easy-cheap-fast-reliable-techniques/

Note that they aren't used exclusively, but are used where beneficial and in conjunction with other techniques.
KL27x:

--- Quote ---Anybody using it? How do you like it, with a year's worth of hindsight?
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I have not used electric eel's version, but I have tried my own version.

There are major problems with this, in practice.

Yes, you can bridge pads to make a circuit. You can even go out of your way to use as few jumperwires as possible. In some cases, you can even make simple circuits with zero wires, which can look great.

The major problem is it is very difficult to debug. It is much easier to follow jumper wires than it is to see these solder tracks. When the empty pads are tinned (either factory plated or the fact they will inevitably get tinned during building/reworking), it is very difficult to follow half pitch (0.05") solder tracks with the naked eye. All you can see is a sea of tin/solder. And even under mag, where you can see perfectly, it's like being in the suburbs, looking for the tan house with the white fence. But all the houses are tan with a white fence, so you are constantly double-checking your row/column. When looking at a PCB, each trace has a unique shape and you have landmarks. Jumperwires, even if they are all the same color, each one has unique bends and angles and whatnot.

I occasionally use a piece of 0.05" small piece of veroboard, mostly for hacking/adding one component to something. In practice this usually means cutting just a tiny piece barely bigger than the component, just to give a place to put an IC and add jumperwires and small passives. It's usually easier to make PCB for the starting point, and just use these stuffs for modifying that.
techman-001:

--- Quote from: ebastler on July 27, 2019, 08:25:03 pm ---Thanks all for the input so far! In summary, the recommendations seem to fall into three categories:


* SMD chips on DIP adapters, everything else on 0.1" perfboard using through-hole components. Fine for non-critical (low speed) circuits.
* Mount SMD ICs dead-bug style or with Kapton tape under the pins; solder wires (preferaly thin, enamelled) directly to the pins. Should allow for higher speed, due to shorter wires, SMD passives, and availability of a ground plane.
* Do a proper PCB layout right away.
Surprisingly, no votes for dedicated SMD protoboards, unless I overlooked something. That's great information -- exactly the kind of practical feedback I was hoping for.

Approach (1) is what I have mostly used so far. Sometimes I have used (3), but only when I felt reasonably sure of my design, and was hoping to actually use it in my project. So approach (2) is what I will try!

I have a preference for the "sunny side up + Kapton tape" style, I think, rather than using dead-bug mounting. And while I see the point of a ground plane, I like holes and solder pads for the occasional though-hole component and connector. Come to think of it -- I used to have some plated-through perfboards with square pads on one side, and very small pads and a ground plane on the back. Haven't seen those in a while, but they must still be available?

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This is a deadbug technique I'm experimenting with. I have more pictures and details on my doc page at:
 https://mecrisp-stellaris-folkdoc.sourceforge.io/prototyping.html#prototyping

tautech:

--- Quote from: ebastler on July 27, 2019, 08:25:03 pm ---Surprisingly, no votes for dedicated SMD protoboards, unless I overlooked something.

--- End quote ---
Maybe there's just not a good selection.
Here's Dave's mailbag vid where he shows off a selection posted in:

https://youtu.be/MwL3qgMNYLc?t=1743


--- Quote from: Miti on July 27, 2019, 10:09:19 pm ---Yes, forget TH. Dive into SMD and never look back.

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Well yes and no.
You'll see jumpers used in modern SMD design when it's nuts to add another layer and so increase PCB cost when sometimes the use of a TH passive or 2 can open the routing pathways required so that even a jumper might not even be required. Otherwise to keep the design SMD get a selection of 1206 or 1210 passives to allow for a wider footprint to route traces under.
Depends a bit on how much TH stuff you have and want to hold onto but if you're doing any repairs you really should hold onto your TH components.

Each to their own I guess and I've found the occasional use of TH passives can restrict projects to just 1 or 2 layers.
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