If you’ve ever looked inside a cheap calculator, a power supply, or a simple LED light, you’ve seen a single sided PCB. It’s the most basic type of circuit board – copper traces on only one side, components on the same side, and no plated through‑holes for vias. It’s not fancy, but it’s incredibly useful.

For many electronic products, a single sided PCB is exactly what you need. It’s low‑cost, easy to manufacture, and reliable enough for thousands of applications. Let’s explore what a single sided PCB is, why you might choose it, and when you should consider upgrading to something more advanced.

What Is a Single Sided PCB?

A single sided PCB (also called a single‑layer board) has a layer of copper on only one side of the insulating base material (usually FR4 fiberglass). All the copper traces, pads, and components are on that same side. There are no plated through‑holes to connect to the other side – because there is no other copper layer.

Think of it as the simplest possible circuit board. You have a flat sheet of insulating material. On top, you have copper lines that connect component leads. That’s it.

How Is a Single Sided PCB Made?

The manufacturing process is straightforward:

1. Start with copper‑clad board – A sheet of FR4 (or other insulator) with copper foil laminated on one side.

2. Drill holes – For through‑hole components, holes are drilled where leads will go. (Surface‑mount designs skip this step or use different tooling.)

3. Apply photoresist – The board is coated with a light‑sensitive film.

4. Expose and develop – A film negative of the circuit pattern is placed over the board and exposed to UV light. The exposed areas harden; unexposed areas are washed away.

5. Etch – The board is bathed in a chemical that removes unprotected copper, leaving only the desired traces.

6. Strip resist – The remaining photoresist is removed.

7. Apply solder mask – A protective coating (usually green) is applied over the traces, leaving pads exposed.

8. Silkscreen – White text and component outlines are printed.

9. Surface finish – Pads are coated with HASL, ENIG, or OSP to make them solderable.

10. Electrical test – A quick test checks for shorts and opens.

11. Route or score – Individual boards are cut from the panel.

No inner layers. No lamination of multiple cores. No buried vias. Simple and fast.

Why Would You Choose a Single Sided PCB?

Cost is the number one reason. Single sided PCBs are the cheapest to manufacture because they use less material, fewer steps, and simpler tooling. Here are the main advantages:

• Low cost – For high‑volume production, single sided boards can cost pennies each.

• Fast turnaround – Fewer process steps mean quicker delivery.

• Easy to design – You don’t need complex routing or impedance control. Beginners can design them.

• Easy to repair – All traces and components are visible and accessible on one side.

• Good for low‑frequency, low‑density circuits – Perfect for power supplies, sensor interfaces, LED boards, and simple consumer electronics.

Where Are Single Sided PCBs Used?

You’ve probably used dozens of products with single sided PCBs without knowing it:

• Power supplies – Simple AC‑DC converters, phone chargers, LED drivers.

• Consumer electronics – TV remote controls, clocks, calculators, radios, toys.

• Sensors and detectors – Smoke detectors, motion sensors, temperature monitors.

• Lighting – LED light strips, indicator boards, decorative lights.

• Industrial controls – Relay boards, simple motor controllers, timers.

• Automotive – Non‑critical interior electronics like window switches or light modules (though many modern cars use more advanced boards).

Even in the age of smartphones and smartwatches, single sided PCBs are still produced by the millions for products that don’t need complexity.

Single Sided vs. Double Sided vs. Multi‑Layer – A Quick Comparison

Can a Single Sided PCB Use Surface‑Mount Components?

Absolutely. Single sided boards are not limited to through‑hole parts. You can place surface‑mount components (SMDs) on the same side as the copper traces. In fact, many modern single sided designs use mostly SMDs to save space and assembly cost. The only limitation is that you can’t place components on the bare substrate side (there’s no copper there to solder to). So all components must go on the copper side.

What About Flexible Single Sided PCBs?

Yes, single sided flexible circuits are common. Instead of FR4, the base material is polyimide (like Kapton). The copper is on one side, and a polyimide coverlay protects it. These are used in simple flex applications like membrane switches, ribbon cables for moving parts, or low‑cost wearables where only a few connections are needed.

If you need a board that bends but only has a handful of traces, a single sided flexible PCB is an affordable option. We manufacture these as part of our custom flexible PCB service.

When Should You NOT Use a Single Sided PCB?

Single sided boards have limitations. They are not suitable for:

• High‑density circuits – If you have many components or complex routing, you’ll need more than one copper layer.

• High‑frequency signals – Lack of a ground plane can cause signal integrity issues above a few MHz.

• Very compact designs – You can’t cross traces without a jumper wire (or a zero‑ohm resistor). Double sided or multi‑layer boards let you route traces on different layers.

• High‑power or high‑heat – Single sided boards often have no thermal vias, so heat dissipation is limited.

The Jumper Wire Trick on Single Sided Boards

Here’s an old‑school trick: when a single sided board needs a trace to cross another trace, you can use a jumper wire – a piece of insulated wire soldered between two points, arching over the other traces. It works, but it’s messy and not suitable for automated assembly. For modern designs, it’s better to use a double sided board or reroute the traces.

Single Sided PCBs in Prototyping

Single sided boards are great for hobbyist prototypes. You can even make them at home using toner transfer or UV exposure. But for professional prototypes, you still order from a PCB manufacturer – and single sided is the cheapest and fastest option.

How to Order a Single Sided PCB from a Manufacturer

When you request a quote, you’ll need to provide:

• Gerber files – The standard format for PCB manufacturing.

• Board dimensions – Length, width, and thickness (typically 1.6mm for FR4).

• Material – FR4 is standard. For flex, specify polyimide.

• Copper weight – Usually 1oz (35µm) or 0.5oz (18µm).

• Surface finish – HASL (cheapest), ENIG (better for fine‑pitch), or OSP (very cheap, short shelf life).

• Solder mask color – Green is standard, but others are available.

• Silkscreen color – Usually white.

• Quantity – From a few pieces to millions.

Why Work with a Manufacturer That Also Does Advanced Boards?

We’re a custom circuit board manufacturer that specializes in flexible PCBs, rigid‑flex boards, HDI high‑frequency boards, and PCBA. But we also make single sided PCBs – lots of them. Here’s why that matters for you:

• One‑stop shop – You can start with a simple single sided prototype, then upgrade to double sided, flex, rigid‑flex, or HDI as your product evolves. You don’t need to find a new manufacturer each time.

• Quality consistency – The same team, same processes, same quality standards from simple to complex.

• PCBA capability – We don’t just make bare boards. We can also assemble your single sided PCB with components, test it, and ship ready‑to‑use boards.

• Flexible and rigid‑flex options – If your product later needs bending or moving parts, we can help you migrate from single sided to flexible.

Real‑World Example: A Simple LED Lamp Manufacturer

A customer wanted a low‑cost LED lamp with a few LEDs, a resistor, and a switch. The circuit was simple. We recommended a single sided FR4 board with HASL finish. The board cost less than $0.50 each in volume. The customer saved money and got a reliable product. Later, they added a Bluetooth module and needed a more complex design – we moved them to a double sided flex‑rigid hybrid. But for the initial simple product, single sided was perfect.

Final Answer – What Is a Single Sided PCB?

A single sided PCB has copper traces on only one side of the insulating base. It’s the simplest, cheapest type of circuit board, ideal for low‑density, low‑cost, and low‑frequency applications like power supplies, remote controls, and LED lights. It can be rigid (FR4) or flexible (polyimide). While it has limitations, it remains a workhorse for millions of electronic products.

If your product needs a simple, reliable, and affordable circuit board, start with a single sided PCB. And when you need to add more complexity, we’re here to help you upgrade to flex, rigid‑flex, HDI, or PCBA.