Introduction

Growing up, using perforated board (Perf-Board) and Stripboard were the ways things got prototyped. With surface-mount, although it is possible to straddle 0603 sized components and SOT-23 semiconductors across stripboard rails quite well, soldering SMD integrated circuits gets awkward without a printed circuit board (PCB) or an SMD breakout board of some sort.

I've never been very happy with the off-the-shelf SMD breakout boards that I have seen, so a while back I tried to create my own. I've been using them for several years and found some of them useful. This very short blog post just explains how I use them, and the PCB files are attached so that anyone can order them from any PCB manufacturer if they look suitable to meet needs.

SMD Proto Board Features

The photo above shows some of the boards in typical use.

The boards are intended for SOIC and TSSOP sized integrated circuits. There is also a board for SOT23 sized parts (including SOT23-5 and SOT23-6), and another board to breakout from 0.5 mm or 1 mm pitch flat flex connectors. The most useful ones to me have been the SOIC boards, followed by the TSSOP boards.

There is lots of bare trace from the integrated circuit to the through-hole pads, and that is handy if any 0402/0603/0805 sized passives need to be soldered across adjacent connections.

The underside of each board contains a ground area directly beneath where the IC is soldered, and this is very handy for individually grounding any pin on the IC, by soldering a wire in a through-hole pad and folding and soldering the wire into that central ground area.

Any hole on the board that is connected to a square pad, is also connected to the ground area. Any pad with rounded edges is not grounded.

Ordering Them

For low cost, a single 100 x 82 mm board contains all of the SMD designs. There are four copies of the SOIC design (one in each corner), two of the TSSOP design, one FFC design, and two SOT23-6 compatible designs all on the single board. There is an approximate 2.6 mm gap between the boards, so that they can be chopped up with a small hobby-grade table saw (wearing goggles and a dust mask). If such a saw is not available, then it may be possible to use a Dremel tool or some other cutting or scoring method, but I have not tried it. The board does not have mouse-bites or scored cuts because that increases the production cost.

EDIT: Individual sets of Gerber files for the SOIC, TSSOP and dual SOT23 are also now attached to the blog post, if you don't have a suitable table saw or other method. It costs about $5.50 to get 20 boards made up, and it will save having to manually cut them).

Optionally, the larger board might not need to be cut if the prototype circuit to be implemented will contain several integrated circuits.

See the photo below which shows the chopped-up result for all of the SMD designs on the board. As can be seen in the photo, the underside contains the central ground plane area.

I used JLC PCB but any PCB manufacturer could produce this board. The attached zip file can be uploaded to the PCB manufacturer website as-is, and it will automatically extract the files and know what to do with them. It cost me $5 plus postage costs to receive ten boards, which should last me for several years of prototyping.

Other Surface Mount Ideas

Copper tape can be used for surface-mount prototyping too.

Tools

Personally, I solder nearly all surface mount parts with a single-sized soldering iron bit; 1 mm slice off conical. 0.38 mm solder is great for surface mount; not so thin that there is little flux in it, and not so thick that everything looks blobby afterward.

Nerd-goggles help too, they magically give teenager level optical focus to older adults, and can be flipped up quickly when longer-range vision is required:

(Image source: Optivisor)

To pick up the parts, I like the center tweezer-style; squared-off tweezer tips, because a lot of surface area can grip the part, and greatly reduce the risk of the part launching into the air.

These particular tweezers are no longer made, but Wiha 32325Wiha 32325 looks similar (1mm wide squared off tweezer tips). I think the tweezer quality is critical to positioning a component precisely and flat on the board. Poor tweezers result in terrible surface-mount soldering capability.

Components

The photo here shows different sized passive components, in comparison to normal 0.1" stripboard:

If you're new to surface mount, then the best size to use is either 0805 or 0603. Both have about the same level of simplicity, there's not much in it, and both will usually fit on circuit boards with 0805 or 0603 sized pads interchangeably.

0402 is significantly more difficult to use without a fine soldering iron and fine solder, whereas 0805 and 0603 can be used with larger irons and solder if nothing else is available. There's usually no point in using 0402 parts since larger sizes will be more reliable to produce with. 0402 is usually only necessary for certain high-frequency applications including very high-speed logic devices.

0201 is pointless unless you like making life extremely hard for yourself, or if you're designing very dense or compact handheld or wearable products (as an example).

A resistor kit and a capacitor kit could be handy for prototyping. They are available off-the-shelf, or you could buy the components in (say) quantities of 50 and build your own kits. I used florist greeting card envelopes to build the resistor kit shown below (cost about £85GBP+tax for 170 different values, 100 of each) with strips of components in each envelope. In hindsight, a ready-made resistor kit would be an easier purchase to save effort. The right side trays contain mainly capacitors and inductors and a few resistor values, but it is time-consuming to fill the trays.

Summary

The SMD proto boards are (I feel) easy to use, and really help save time prototyping with surface mount integrated circuits. Although some effort is needed to cut them out, it just needs to be done once and it is possible to have sufficient boards for many years of prototyping hopefully, with near-negligible cost.

Some other basic prototyping ideas and tools were discussed, but this is just from my limited perspective and there will be much better ways and equipment. Any suggestions or links would be appreciated.

Thanks for reading.