Once you have confirmed that a circuit works well on perfboard, you may want to move it to a custom-ordered PCB (printed circuit board) to make several of the same circuit, shrink it, or make it more reliable. Today there are many online PCB services, so individuals can order small quantities. This article covers the flow up to ordering a PCB, the manufacturing files you need (Gerber and drill), criteria for choosing specs, what drives cost, and a pre-order checklist. This is an overview of the process, and since prices and policies vary by service and change often, check the manufacturer's guidance at the time of ordering.
How a PCB differs from a perfboard
A PCB is a board with the part placement and wiring (copper pattern) printed in advance. You draw a schematic in design software, lay out the parts and copper routing, and a manufacturer makes it from that drawing (Breadboard vs. Perfboard vs. PCB). Note that a perfboard tool like Patterndo is not PCB design software. A perfboard layout can serve as the starting point for PCB design (the parts list and connection information), but the routing has to be designed anew in PCB software.
The overall flow
- Draw the schematic: draw the parts and connections in design software (Free Circuit Design Software Compared, Reading Schematic Symbols).
- Assign footprints: decide the pad shape each part takes on the board (DIP, SMD, and so on).
- PCB placement and routing: set the board size, place the parts, and draw the copper routing.
- Design rule check (DRC): check that trace spacing, hole sizes, and so on meet the manufacturer's specs.
- Generate manufacturing files: export the Gerber files and the drill file.
- Upload to the manufacturer and choose specs: decide the number of layers, thickness, color, surface finish, and so on, and place the order.
- Fabrication, shipping, and soldering parts: fabrication usually takes a few days, and 1 to 3 weeks including shipping.
Manufacturing files: Gerber and drill
The standard file sent to the manufacturer is the Gerber. There is a separate file for each layer.
| File content | Typical name examples |
|---|---|
| Top copper | .GTL (or F_Cu) |
| Bottom copper | .GBL (or B_Cu) |
| Top and bottom solder mask (green coating) | .GTS, .GBS |
| Top and bottom silkscreen (text) | .GTO, .GBO |
| Board outline | .GKO, .GM1 (Edge Cuts) |
| Holes (drill) | .DRL, .XLN |
Design software has a function that makes these files in one go, so export them in the format the manufacturer's guidance asks for, zip them, and upload. After uploading, check the shape once more with the preview on the manufacturer's screen and a Gerber viewer.
Choosing specs
Number of layers
- 1 layer (single-sided): cheapest and suited to simple circuits, but nowadays 2 layers is common since the price difference is not large.
- 2 layers (double-sided): wiring on both front and back, connected with plated holes. Most common for beginners.
- 4 layers or more: dedicated power and ground layers, used for fast, complex circuits. Costs go up.
Thickness and copper
- Board thickness: 1.6 mm is standard.
- Copper thickness: 1 oz (about 35 µm) is standard, and for circuits carrying large current consider 2 oz.
Surface finish
The protective treatment of the pads where solder sticks.
| Type | Characteristics |
|---|---|
| HASL (leaded or lead-free) | Cheap and common, surface slightly uneven |
| ENIG (electroless gold plating) | Flat surface and good shelf life, favorable for SMD, expensive |
Other choices
- Solder mask color: green is the cheapest and most common. Other colors may add cost or lead time.
- Silkscreen: adding part numbers and polarity marks makes assembly easier.
- Minimum trace width and spacing, minimum drill diameter: design within the manufacturer's default specs (for example, trace width and spacing around 0.15 mm, drill around 0.3 mm) to avoid extra cost. Check the manufacturer's spec page before designing.
What drives cost
- Board size: the bigger the area, the more expensive. Below a certain size, small orders are often priced about the same.
- Number of layers: going from 2 layers to 4 layers raises it a lot.
- Quantity: small orders have a high unit price, which falls as quantity rises. 5 to 10 boards is usually the minimum.
- Surface finish and special specs: ENIG, thick copper, and special colors cost extra.
- Shipping method and time: fast shipping is expensive. If you are not in a hurry, standard shipping is economical.
- Assembly (SMT) service: having them mount the parts is convenient, but parts cost and setup cost are added.
Price structures differ by manufacturer and time, so check the quote right before ordering.
Pre-order checklist
- Did you check in a Gerber viewer that every layer's shape matches the design?
- Is the board outline a closed shape? Are hole positions and sizes right?
- Are trace width, spacing, and drills within the manufacturer's minimum specs?
- Is the orientation of polarized parts (electrolytic capacitors, diodes, LEDs, ICs) marked on the silkscreen?
- Do connector and switch positions match the case? Does the hole spacing fit the 2.54 mm grid?
- Are the power and ground traces thick enough? (Power Rails, Grounding, and Decoupling Capacitor Placement)
- Do the part footprints match the real parts? If possible, print it 1:1 on paper and place the parts on it to compare.
- Did you include test points and a test header (power, ground)?
Advice for your first PCB
- Verify on perfboard first, then move to a PCB. Finding a circuit error on a PCB costs twice the time and money.
- At first, design with through-hole (DIP) parts to lower the soldering difficulty.
- Do not try to finish a board in one go; make the first run a "test board", collect the fixes, and reflect them in the next one.
- Save your design and keep versions.
Summary
Ordering a PCB goes schematic → placement and routing → DRC → Gerber and drill → upload to the manufacturer. Start with standard specs like 2 layers, 1.6 mm, and HASL, design within the manufacturer's minimum specs, and always check with a Gerber viewer before ordering. If you are curious about design tools, see Free Circuit Design Software Compared.