Single-Layer vs. Multi-layer PCB
When it comes to fabrication, manufacturers have a choice between single-layer and multi-layer PCB stack-ups. Both have their scope of applications, strengths, and limitations. But all of those may not be obvious. Here, in PadPCB, we offer both PCB types of the highest quality, so we ought to provide extra details.
Let’s review single and multi-layer stack-ups so the difference is clear and you can choose a perfect fit for your projects.
Single vs Multi-Layer PCB: the Main Difference
To be precise, there are also double-sided boards, which hardly can be attributed to single-layer or multi-layer PCBs alone. Let’s assume those are the advanced versions of single-layer stack-ups and move forward.
Single-layer board is a most simple PCB that is made of a substrate laminated material (FR-4, Rogers, Teflon, etc.). It has components on one side only, and the conductor pattern on the other side.
Such boards are protected with solder masks and silkscreen layers. Copper serves as a conductive metal here. It transfers electrical signals across the board via the traces. PCBs may have a finish (for example, thin silver plating), but it’s optional. See an example in the image below.
In its turn, a multi-layer PCB can comprise multiple double-side layers, having components on the one side and insulation layers on the other side. It naturally comprises cores and prepregs coated with copper layers. These are connected with vias and holes. See an example in the image below.
Quick fact: The largest multi-layer PCB ever was 129 layers thick. You may choose any number of layers you want. But ones with odd numbers of layers are typically problematic in fabrication because of twisting and warping effects.
Here, in PadPCB, we offer standard 2 to 30-layer boards but are always willing to help you with customized concepts.
In essence, the main difference between single-layer PCB and multi-layer PCB is that the first is a substrate with components on one side while the second is a bunch of double-layer boards laminated together.
Why Should You Use Single-Layer PCB?
Let’s see what are the factors making you opt for single-layer boards:
What are the Benefits of Using Single-Layer PCB?
These are mostly linked to their simplicity in production and use:
- Affordable. Naturally, single-layer PCBs do not cost much per board. But they still may be functional enough to be used in some popular types of electronics. So, using well-designed single-layer PCBs instead of cobbled together double-layer or multi-layer PCBs reduces expenses significantly.
- Short turnaround time. Usually, manufacturers do not have difficulty fabricating your single-layer PCBs on time. They rarely can be poorly produced or rejected during quality testing.
- Production simplicity. In case you are deciding on DIY fabrication, single-layer PCBs are the perfect options to start with. Alternatively, their rapid prototyping with the help of a PCB provider should not take much effort.
- Lower risks of malfunctioning. Well-designed single-layer PCBs are more long-lasting than alternative double-layer boards. They have fewer weak points and fewer connections that can possibly fail.
- Can be reworked. The simplicity of single-layer PCBs makes it possible to reuse materials multiple times with zero to no losses. They also can be relatively reassembled and repaired.
What are the Downsides of Using Single-Layer PCB?
Unfortunately, such simple boards come with disadvantages you should consider before going for them.
- Design limitation. The biggest con is that there is not enough space for routing and mounting a large number of components. It’s just difficult to fabricate a high-performance single-layer board. So, their usage is strictly limited.
- Cannot host many connections. The minimal number of connective joins that a single-layer PCB may have affects its functioning. Typically, such boards just cannot compete in the matter of operating speed with double/multi-layer PCBs.
- Large and heavy. Single-layer PCBs do win in the matter of thickness against multi-layer PCBs. But if you need to accommodate more components on one side only, you will have to enlarge the dimensions of a board overall. This will impact its size and weight accordingly.
Why Should You Use Multi-Layer PCB?
What are the Benefits of Using Multi-Layer PCB?
What are the Benefits of Using Multi-Layer PCB?
These are mostly linked to the level of performance they promise:
- Suitability for complex designs. Multi-layer boards have enough space for routing and mounting components without compromising size. It makes them sufficient for both advanced and microelectronics. Most multi-layer boards may also have additional features, including electromagnetic interference shielding, or suit high-frequency applications.
- Powerful. These boards do not have strict limitations on operating speed and operating capacity. So they suit electronics of any level of complexity.
- Small size and weight. Despite having multiple boards, a multi-layer PCB may be extremely small. It also impacts gross weight positively.
- Durability. Multi-layer boards are capable of withstanding harsh conditions successfully. Their flexible versions are also more reliable, as an extra advantage.
What are the Downsides of Using Multi-Layer PCB?
- Expensive. It’s frequent that a multi-layer board costs multiple times more than a single-layer one. Just for the reference: laminating an extra double-layer board (two layers more to the stack-up) causes a 30-40% cost increase.
- Complex repair. The issue is that double-layer boards laminated together hardly can be reworked. Even though it is a time and resource-consuming process.
- Longer turnaround time. Fabrication of multi-layer PCBs includes way more stages. Besides, a greater portion of them may be rejected during quality testing. Another factor is the complexity of their design that contributes to the duration of rapid prototyping.
Single and Multi-Layer PCB: A Comparison Breakdown and Overview
| Factor | Single-Layer PCB | Multi-Layer PCB |
|---|---|---|
| Layers | Substrate layer only plus components and conductor patterns | Cores, prepregs, components, conductor patterns, insulation layers |
| Material | Substrate material (FR-4, Teflon, CEM, and others) plus copper plating | Substrate material (FR-4, Teflon, CEM, and others) plus copper plating |
| Cost | Such boards are priced much lower per unit | Such boards can be priced highly per unit |
| Reworking | Comparatively simple rework and repair | Complex rework and repair which is not always possible |
| Applications | Simple/affordable retail electronics. Radios, printers, LED lights, sensors, power suppliers, Solid State Drives (SSD), etc. | High-tech/expensive electronics for both retail and industrial needs. Satellites, GPS, broadcast systems, X-ray, computerized electronics, IoT. |
| Rapid prototyping and turnaround time | Short | Typically long |
| Manufacturing process | Fabricating substrate, copper coating, etching, silkscreening, soldering, finishing. | Fabricating substrate, copper coating, etching, silkscreening, soldering, laminating double-layer board together, finishing. |
Single vs Multi-layer PCB – Which One is Better?
It’s rather an abstract question “which one of the equally widespread types of boards is better?” The answer lies in your technical requirements. In case you manufacture any of the mentioned electronic types, you may opt for a perfectly matched board.
Alternatively, you need to consider these aspects to make a good choice yourself:
- The design complexity required. A single-layer PCB may not physically accommodate the needed routing and the number of components because of the lack of space.
- The acceptable size. If the matter is thickness, a single-layer board may be a better choice. But if the crucial aspect is dimensions, you’ll benefit the most from multi-layer PCBs.
- Physical and electrical characteristics. Multi-layer PCBs are more durable naturally. They also show better conductive and other electrical properties. They also may be more energy-effective compared to the functionality supported.
- Your budget. If you need more boards at a lower cost, single-layer PCBs are definitely your first choice.
- Turnaround time. Lack of time is rarely an issue. But still, if you face a scarcity of it, you shall consider that fabricating single-layer PCBs takes much less time.
In case you are still unsure about what PCB type will meet your need, you may request a free quote from us. We’ll get back to you shortly with a detailed explanation.
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