What is the Standard Thickness of a PCB?

A Printed Circuit Board (PCB) is the foundation of electronic devices, which serves as a substrate to support electrical components. In PCB design, thickness is a crucial parameter as it influences several key processes. It influences not only the mechanical performance of the board but also its electrical properties, manufacturability, and overall cost. The prevailing PCB thickness is 1.6 mm, but there will be many further options suitable for various purposes. Knowing the rule and when it’s acceptable to break it regarding your PCB thickness can help designers make a decision that will keep your circuit board functioning as intended.

If you want to explore different PCB thickness options for your next project, you can easily customize them when placing an order at JLCPCB. Their instant online quote lets you compare prices and lead times across multiple thicknesses.

What Is the Standard PCB Thickness?

1.6 mm (0.062 inch) is the most common standard PCB thickness. This dimension is the industry standard because it strikes a balance among mechanical strength, manufacturability, and compatibility with most electronic assemblies. A 1.6 mm board is rigid enough for structural handling, yet thin enough to fit into compact devices.

However, 1.6 mm is not the only option. JLCPCB provides a wide range of standard FR-4 board thicknesses to meet different mechanical and space constraints:

·0.4 mm – ultra-thin option popular in wearable devices, SIM card modules, and compact sensors.

·0.6 mm – lightweight design suitable for highly space-constrained enclosures and smart cards.

·0.8 mm – popular in compact consumer electronics and portable IoT equipment.

·1.0 mm – often used in handheld devices, small form factor boards, and mobile accessories.

·1.2 mm – a balanced alternative for mid-sized devices requiring reduced weight without losing stability.

·1.6 mm – the universal standard for general-purpose electronics, mainboards, and industrial controls.

·2.0 mm – chosen when extra rigidity is needed for boards with heavy components or high-vibration environments.

·2.5 mm to 3.0 mm – applied in high-power electronics, automotive PCBs, and heavy-duty industrial systems where high    mechanical strength is critical.

These thickness options are readily available to satisfy varying engineering requirements, but 1.6 mm remains the primary go-to choice for universal PCB manufacturing.

Factors That Determine PCB Thickness

Number of Layers & Stackup Architecture
The number of layers directly influences the choice of core substrates and prepreg (PP) materials. A standard 2-layer board easily defaults to 1.6 mm using a single thick core substrate.

For multilayer PCBs (e.g., 4, 6, 8, or 12 layers), maintaining a total thickness of 1.6 mm requires precise stackup adjustments. Fabricators like JLCPCB use thinner dielectric cores (e.g., 0.1 mm–0.2 mm) and thin prepreg sheets (such as 7628, 2116, or 1080 PP) between copper foils. While 8 to 12-layer boards can still be manufactured at 1.6 mm total thickness, designs exceeding 12–16 layers often require an increased overall thickness (e.g., 2.0 mm or 2.5 mm) to preserve mechanical stability, microvia reliability, and fabrication yields.

Mechanical Rigidity & Thermal Management

Thicker substrates increase structural stiffness, preventing sagging or warping during thermal processing (reflow soldering) and physical handling. This is ideal for heavy industrial power supplies or automotive electronics subjected to high vibration. Conversely, thinner boards (0.4 mm–0.8 mm) are essential for weight-sensitive applications like wearables and IoT devices.

Board thickness also plays a crucial role in thermal dissipation. Standard FR-4 has a relatively low thermal conductivity (~0.3 (W/m·K)). A thicker FR-4 dielectric increases vertical thermal resistance (R_th = d/k·A), making heat transfer from top-layer components to bottom heat sinks slower. To mitigate heat buildup on thicker boards, designers must utilize thermal vias, thicker inner copper layers (e.g., 2 oz copper at JLCPCB), or alternative substrates like Aluminum-core PCBs.

Electrical Performance

PCB thickness also affects the electrical characteristics of the board. For example, the use of controlled impedance is critical for high-speed and/or high-frequency designs. In which the thicknesses of dielectric layers between copper planes directly affect signal quality and exchange, thus overall signal integrity. In which the designers also often speak with PCB fabricators to determine which stack-up and how much thickness is best for a specific application to achieve stable and reliable electrical performance.

Manufacturing Standards and Cost

A better alternative is to settle on a standard thickness such as 1.6 mm. It conforms to the PCB thickness of the IPC-2221 standard and is regularly used by most PCB fabrication houses. Moreover, these options are easier to acquire and make and cost less. Although it is possible to have thicker or thinner PCBs, these will increase lead times and overall PCB production costs.

Standard PCB Thickness Options and Applications

The following thickness ranges are commonly used in the industry, each serving different applications and manufacturing requirements:

It reflects that 1.6 mm is the universal standard, yet designers maintain a free choice of thickness according to performance and mechanical requirements.

How to Select the Right PCB Thickness

Consider Electrical Requirements & Impedance Control

In high-speed and RF PCB designs, substrate dielectric thickness between signal traces and reference planes directly determines the characteristic impedance (Z0) . For a standard microstrip line, characteristic impedance is governed by:  Z0 ≈ (87 / √(εr + 1.41)) * ln(5.98 * h / (0.8 * w + t))(where h is dielectric thickness, w is trace width, t is copper thickness, and εr is dielectric constant)

A thinner dielectric layer (h) allows for narrower trace widths (w) to achieve target 50 Ω single-ended or 90/100 Ω differential impedance, which is crucial for dense BGA routing. Fabricators like JLCPCB provide pre-calculated impedance stackup templates (JLC-Impedance tool) to simplify high-speed layout design.

Consider Mechanical Requirements

If your board is likely to experience physical stress, vibration, or connector mating, then you may benefit from increasing the thickness up to 2.0mm or above. Thinner boards are preferred, on the other hand, for portable or wearable devices and handheld equipment.

Consider Manufacturing & Cost

Some common thicknesses are also more readily available and cheap, such as 1.6mm/1.2mm. Custom configurations are sometimes required for unique projects, but they can typically come with higher fabrication costs and a larger lead count. We adhere to the industrial standard and acceptance, making it easier to trace the production.

PCB Thickness vs. Layer Count

It is a common misconception that more layers automatically result in a thicker PCB. A 1.6 mm PCB can easily accommodate anywhere from 2 up to 12 (or even 16) layers by using thinner cores and prepregs.

However, when selecting thickness for high-layer-count boards (12+ layers), designers must consider the Drill Aspect Ratio (Board Thickness : Drill Diameter). Fabricators like JLCPCB typically maintain a maximum aspect ratio of 10:1 for standard PTH (Plated Through Hole) processing. For instance, on a 2.0 mm thick board, the minimum reliable mechanical drill size is:

Min Drill Diameter =Board Thickness/10 = 2.0 mm/10 = 0.2 mm

Choosing an overly thick board with tiny vias can lead to plating solution flow issues inside the hole, resulting in unplated via walls and board failure. Non-standard thickness custom configurations may also lead to higher fabrication costs and longer lead times.

FAQ about Standard Thickness of a PCB

Conclusion

It’s easy to dismiss the thickness of the PCB as trivial when first designing it; however, there are implications for mechanical strength, signal quality, layer stack-up sequencing, and even price. PCBs come in different thicknesses, the most popular being the 1.6 mm industry standard, but they can range from 0.2 mm up to 3.2 mm or above! The trade-off between performance and manufacturability, this thickness is the sweet spot for most applications.