On an individual-pad perfboard, you have to join every pair of holes you want connected yourself. How you make those connections greatly changes the work time, appearance, and reliability. This article covers the characteristics of the three connection methods used on perfboards, their length limits, and rules that prevent shorts.
Three ways to connect
A. Solder bridge
A method of joining two neighboring holes (1 hole apart) directly with solder. It is the fastest and needs no wire.
- Pros: takes almost no time and looks neat.
- Cons: only possible up to a distance of 1 to 2 holes, and joining more than intended makes a short. You have to control the amount of solder so it does not accidentally join the neighboring pad.
- Where to use: connecting neighboring holes in the same row (for example, making a power rail or joining part leads).
B. Tinned wire or part-lead wiring
A method of laying bare wire (tin-plated wire) or a trimmed part lead along the holes on the copper side and soldering at each hole it passes.
- Pros: it connects all the holes in between at once, and the wire is held firmly by the solder.
- Cons: a bare wire that crosses another wire makes a short. If other solder joints sit on top of the wire, problems are hard to find.
- Where to use: connections of about 4 to 10 holes within the same line, and power and ground rails.
C. Jumper wire (insulated wire)
Insulated wire (vinyl or enamel) is stripped only at both ends and soldered into two holes. It does not short even when it passes over other wiring.
- Pros: no limit on distance or direction, and it can cross.
- Cons: the more jumpers, the more work, and the wires tangle. If one solder joint comes off, it is hard to find the fault.
- Where to use: diagonal or long-distance connections, and when you must cross existing wiring.
The shorter the jumper, the better
Long jumper wires look messy and are hard to reposition after soldering. Setting a guideline helps.
- Keep them within 10 holes where possible. Patterndo's auto-rewire also limits jumpers to within 10 holes and places them so they do not overlap or cross.
- Lay them neatly in one direction and avoid diagonals across the board.
- Cut the jumper slightly longer than the distance between the two holes, but not so long that it sags.
Rules that prevent crossings and shorts
- No crossing of bare wires: if you have to cross, change one side to an insulated jumper.
- Check the spacing of adjacent pads: keep the round solder shape from touching the neighboring pad. Use a fine tip and little solder.
- Wire end preparation: strip only 2 to 3 mm of insulated wire and pre-tin both ends.
- Under part bodies: running bare wire under a part body makes problems hard to find later. Avoid it where possible.
- High-current lines: use thicker wire and a thicker layer of solder for power and motor lines.
Wire colors and tidiness
Deciding wire colors makes checking easier.
| Use | Recommended color |
|---|---|
| Power (+V) | Red |
| Ground (GND) | Black or blue |
| Signal, other | Yellow, green, white, and so on |
The Patterndo editor also shows power wiring in reds and ground wiring in blues, so if you solder with wire of the same colors while looking at the wiring you drew in the editor, you will not get confused.
An efficient wiring order
- Finish power and ground first.
- Make the short connections (solder bridges and part-lead connections) first.
- Do the bare-wire runs.
- Lay the jumpers on last.
- Each time you finish one wire, check it off on the drawing and confirm with a continuity test.
Summary
Connect close holes with a solder bridge, medium distances in the same line with tinned wire, and long or crossing connections with a jumper wire. Keeping jumpers short, bare wires free of crossings, and checking each wire with a continuity test prevents faults. If the wiring has become complicated, you can look for shorter paths with Using Auto-Rewire, and if soldering itself feels shaky, review Perfboard Soldering Basics.