A perfboard is, as the name says, a board you can build anything on. The circuit pattern is not printed in advance; the board has only holes at regular intervals, so you insert parts and solder on the back to build the circuit you want yourself. In English it is also called a perfboard (perforated board) or a prototyping board. This article covers the structure and types of perfboards and what to check when choosing one for the first time.
The structure of a perfboard
A perfboard is made of three main parts.
- The board body: an insulating plate. Cheap products use paper impregnated with phenolic resin (phenolic), and sturdier ones use glass-fiber epoxy (FR-4).
- The holes: the holes that part leads go into. The usual spacing (pitch) is 2.54 mm (0.1 inch), and most DIP ICs, pin headers, resistors, and capacitors are made to fit this spacing.
- The pads (copper): the copper-plated area around each hole. Solder sticks here and connects the part lead electrically.
You insert parts from the side without pads (the component side) and solder on the side with pads (the copper side, or solder side). The fact that these two sides are mirror images of each other, left to right, is the most confusing part of reading a layout diagram, so it is covered separately in Reading a Layout Diagram.
Three types by pad shape
1. Individual pads
Each hole has its own separate pad. At first, no hole is connected to any other, so you have to join every pair of holes you want connected with solder or wire yourself. It gives the most freedom to lay out the circuit however you like, but there is a lot of wiring to do. Design tools like Patterndo mostly assume this type.
2. Strip pads
A type where a set number of holes in a horizontal line are already connected. The idea is similar to a breadboard, but the difference is that you solder. When you insert a part such as an IC, its pins are shorted along the strip, so you cut the middle of the strip with a knife or drill. Wiring is easy, but you have to do the cutting.
3. Power rails + individual pads
A type where only one or two lines at the very top and bottom are connected along their length, and the middle is individual pads. It is handy for laying power (+V) and ground (GND) as rails and tapping short connections from the nearest point to each part. It is especially convenient for circuits with several digital ICs.
Choosing size and pitch
Here is how to pick a size that fits your project.
- Count the parts, then leave some room. Add up the space the parts take and the wiring space; allowing 1.3 to 1.5 times the area you need makes wiring easier.
- Count the IC size in holes. A DIP-14 IC has 7 pins in each of two rows at 2.54 mm spacing, with 7.62 mm between the rows (a 3-hole gap), so it takes a 4-hole × 7-hole area. If you have several ICs, a board that is wider than it is tall makes them easier to line up.
- If you plan to put it in an enclosure, check the dimensions first. Some perfboards can be cut with scissors or a cutter, but it is safer to cut along a row of holes.
- Make 2.54 mm pitch your default. There are 1.27 mm and 2.0 mm pitch products, but parts and sockets are hard to find and soldering is tricky.
Material and thickness
| Material | Characteristics | Suited for |
|---|---|---|
| Phenolic (paper phenolic) | Cheap and easy to work, but weak to moisture and bends easily. | Practice, experimental circuits used briefly |
| Glass epoxy (FR-4) | Hard, resistant to heat and moisture, and lasts long. | Finished projects, work soldered and removed repeatedly |
A thickness of 1.6 mm is the most common. Double-sided boards with pads on both sides have plated-through holes connecting front and back, so you can solder from the component side too, but they cost more and a single-sided one is easier to handle at first.
Pre-purchase checklist
- Whether the hole spacing is 2.54 mm
- Whether the pad type (individual, strip, or rail) suits the circuit you will build
- Whether the material is phenolic or FR-4
- Whether the pad plating (tin plating, gold plating, and so on) is clean — solder does not stick well to oxidized pads.
- The stated dimensions and number of holes
If you are just starting, we recommend an individual-pad FR-4 board. Even though the wiring is more work, it helps you understand the circuit most, and it is easy to transfer a layout you practiced in Patterndo straight onto it.
Summary
A perfboard is a general-purpose board made of holes and pads at 2.54 mm spacing. It divides into individual, strip, and rail types by how the pads are connected, and for a first board an individual-pad one is easiest to understand. Next, learn Perfboard Soldering Basics, and before you actually solder, check Reading a Layout Diagram.