A PCB thickness measurement is among the most important measurements in
electronic manufacturing. You know, it affects device performance and
manufacturing costs. Let's learn what PCB thickness really is.
What is Standard PCB Thickness?
A PCB Standard Thickness: 2 Layer PCB Stack-up
Although there is no industry standard for PCB thickness, certain
thicknesses have become common.
Most PCBs are 1.6mm thick (0.063 in). That's the default thickness for
everything from computer motherboards to appliances.
I'm sure you're wondering why 1.6mm? This thickness offers a good
balance between strength and flexibility without costing too much. Engineers
know it gives enough mechanical strength without making things too bulky.
Common PCB Thickness Options
So, you'll totally see 1.6mm
most often. It's the really common thickness. But get this, PCB makers actually
have a bunch of other choices too. They offer these extra options. This helps
them meet specific design needs. For super thin stuff, you might see 0.4mm.
This is great for flexible electronics. It's also used in tiny things like
smartphones. Then there's 0.8mm.
You'll often find this one in
smaller gadgets. Think smartwatches. Some medical equipment uses it too. If
you're dealing with credit cards that have chips, 1.0mm is used, also, for
certain portable electronics. And many everyday consumer devices use 1.2mm.
This is especially when saving space is a big deal.
Of course, 1.6mm is still the standard one. Everyone goes to that for
most regular uses. But what if you need something tougher? Or maybe stiffer?
Makers offer 2.0mm for a bit more rigidity. Go for 2.4mm if you need extra
durability. And for seriously heavy-duty jobs, you'd use thicker boards. We're talking
about things like 3.2mm. These are for stuff like power supplies. Or big
industrial machines that take a beating. So, you see, there's a whole range. It
just depends on what your project needs!
Secondly, you need to understand how thickness relates to specific
uses, such as how thick PCBs are needed for cars. Meanwhile, thin PCBs are
needed for modern phones.
PCB Layer Stack-up and Its Relationship to Thickness
The thickness of a PCB correlates to its layer count and stack-up
design. This is noticeable in circuit board design.
Basic 2-layer PCBs have a thickness of 1.0mm to 1.6mm. The stack-up is
awesome: the core material is FR-4, with two copper layers that are soldered
together, and the silkscreen is on the outside.
We still see 1.6mm PCB thickness for a 4-layer stack, but the inside
structure gets more complex. There are several core layers, prepreg layers, and
copper layers.
Some uses may require a 2.0mm stack-up. The six layer stack-up gets
more complicated, so signal integrity is important.
The biggest mistake is when designers pick layer count without thinking
about how it changes the overall thickness. While layer count and thickness are
linked, it's not easy to tell since makers can adjust how thick each layer is
to meet the board's thickness at the same time.
PCB Manufacturing Considerations for Thickness
It's a challenge when making PCBs of different thicknesses. For thin
boards (under 0.8mm), warping during production is an issue. Make sure your
account for the manufacturing limits in your design.
PCB thickness is also influenced by the size of the panel. Most makers
use standard panel sizes like 18"x24" and 18"x21", so
thickness must stay consistent.
The basics are that thinner boards cost more to make because they're
more complex and more likely to fail. Don't freak out about this cost
increase-it usually balances out with the benefits of smaller size and lighter
weight.
Application-Specific Thickness Requirements
Different uses have different needs, so think about what you'll use,
not what your PCB thickness should be.
Consumer Electronics
In consumer electronics, boards are 1.0mm to 1.6mm thick. These
thicknesses work well for smartphones, tablets, and home entertainment systems.
Manufacturers can keep their products slim and light with 1.0mm boards. Laptops
and gaming systems that need more strength can use 1.6mm boards. Engineers also
know it's great for balancing heat distribution, so it doesn't overheat in
compact devices.
Automotive
For automotive applications, you'll need 1.6mm to 2.4mm. Cars put
electronics under extreme conditions, from engine vibrations to temperature
swings. Thicker boards can withstand these stresses without cracking. Engine
control modules and safety systems need extra protection. 2.4mm options give
them extra protection. In addition, thicker boards provide better heat
dissipation under the hood. It helps handle high currents often required in
automotive applications.
Aerospace
Aerospace might use special thicknesses based on weight and reliability
needs. Spacecraft and aircraft require precision, but reliability can't be
compromised. Think about how aerospace engineers balance these competing
demands, and you'll get ideas on how engineers do it.
The boards of some satellite components could be thinner to save money
on launch, but boards of flight-critical systems need to be thicker and more
reliable. In this industry, custom thicknesses are often needed with special
materials that can handle radiation, vacuum conditions, and temperature swings.
Medical Devices
In medical devices, you may need ultra-thin boards for implant tech or
standard boards for monitoring gear. It's a good idea to design thin boards
(0.4-0.8mm) for implantable devices like pacemakers to reduce discomfort and
improve biocompatibility. Be patient while designing these, as they need a lot
of precision. A standard 1.6mm board is used for external medical monitors in
hospitals. Because internal gadgets have to be miniaturized without sacrificing
safety, but external gear has to handle cleaning chemicals and drops.
Industrial Equipment
There are thicker boards (2.0mm to 3.2mm) for industrial equipment
because factory floors are full of vibrations, dust, and chemicals. These thick
boards resist physical damage and provide stability for heavier components like
power transistors and large capacitors.
They're also thick enough to prevent warping under high temperatures.
The robust designs mean fewer failures for PCB manufacturers, which matters for
industrial applications where downtime costs thousands per minute.
Customers often have good reasons for insisting on specific thickness
requirements based on their use cases, which is why it matters. You want your
device to work as planned while still meeting physical constraints.
Thermal Considerations and PCB Thickness
The thickness of PCBs can also affect heat management. Thicker boards
can sometimes move heat better, which is good for power electronics. Thinner
dielectric layers might be better for high-frequency uses.
Modern electronics run hot, and heat management is important for
performance and lifespan. PCBA companies often recommend certain board
thicknesses based on heat factors.
If you're designing high-power circuits, thermal testing can help you
determine what board thickness works best.
Mechanical Considerations and PCB Thickness
Physical properties are directly affected by board thickness. Thicker
boards are more rigid and can better withstand stress, while thinner boards are
more flexible but can break more easily.
It's important to find the right balance between physical needs and
space constraints. When you're trying to slide a PCB into a tiny case, it has
to make sure it doesn't crack.
When designing flex-rigid PCBs, the thickness difference between rigid
and flexible sections is crucial. PCB thickness chart guides can help engineers
navigate this transition.
Signal Integrity and Impedance Control vs. PCB Thickness
Signal integrity issues grow as PCBs get thinner, especially in
high-speed designs. Thinner PCBs don't always work better for electrical
performance.
A controlled impedance trace needs exact dielectric thickness between
copper layers. This is important to keep the signal quality and prevent
crosstalk.
Choose board thickness based on electrical performance needs and
physical constraints. Sometimes, a slightly thicker board can handle controlled
impedances better while still fitting inside the board's dimensions.
Guidelines for Selecting Suitable PCB Thickness
Start somewhere by checking your application's specific needs:
● Physical space limits
● Expected mechanical stress
● Heat requirements
● Electrical performance needs
● Manufacturing volume and budget
In engineering, balancing these factors takes experience. Take a look
at how thickness impacts not only the board itself, but component mounting,
case design, and connector placement as well.
It might look like there are endless options, but in reality, sticking
with standard thicknesses (especially 1.6mm) usually delivers the best cost,
performance, and manufacturing ease.
If you're making these decisions, don't just copy the specs of another
design without understanding why they were made.
Conclusion
1.6mm remains the most popular PCB thickness across industries.
Understanding how thickness, layer count, and application needs relate is key
to PCB design success.
Choosing the right thickness early in the design process can save you
money later. PCB manufacturers can give you useful tips on thickness selection.
