Printed Circuit Boards have a variety of different layers. The layers can confuse those who are not entirely keen and savvy in the niche.
Most of the PCB prototypes, made quickly are of 2 layers. However, many electronic devices are not limited to double-layer boards. They require higher and finer boards.
This article will aid you in getting a better understanding of PCB layers and how they work.
1、What Are The PCB Layers
1.1 PCB Layers Definition
Printed Circuit Boards have different meanings depending on the message that is to be relayed. Regarding PCB layers, also describe as copper layers given in a certain quantity and order.
The copper layers can be termed as a signal layer or just layers. PCB layers named out of their positioning and the functions that they deliver. PCB's rank according to the number of copper layers.
The boards that have one or two layers, for example, can be termed to be 1-layer PCB or single sided PCB and 2-sided layer PCB or simply double sided PCB respectively.
There are various types of PCB Layers, and the following are the common ones:
1. Mechanical Layer
2. Overlay / Silkscreen Layers
3. Routing Layers
4. Solder Mask Layers
5. Solder Paste Layers
6. Keep Out Layer
7. Ground Planes and Power Planes
8. Split Planes
Remember that not every PCB consists of all the layers enumerated above. The specifics of your design is what determines the need for various layer types. Single layer boards usually comprise six layer types.
These include a mechanical, a keep out, a routing, an overlay, a solder mask as well as a solder paste layer.
When it comes to multilayer PCBs, they consist of the six layers, plus a combination of other power plants, as well as ground planes and additional routing layers.
The two-layer, four-layers and six-layer PCBs are the most common boards, and it is not unusual to have PCBs having more than 12 layers.
1.2 Mechanical Layer
While you may have several mechanical layers, you will still need one – at least – to construct your board. The most basic mechanical layer defines your board's physical dimensions.
The mechanical layer is also known as Mechanical 1. The layer that the fabricator will use in cutting out the circuit board from their material.
Printed Circuit Boards can be as simple as just a single routing layer outlining your board's physical dimensions or as complex as a board with many layers including all the layers mentioned in this article.
On the other hand, when considered separately, every single layer has a particular, and merely a function. It is essential to understand each layer's purpose because the moment you do so, PCB construction becomes extremely simple regardless of how complicated the board is.
This framework can be either of two things: a simple rectangle a complicated shape having curvy corners plus/or cut-outs.
Even though this is rare, more mechanical layers are at times included, specifying tooling specs as well as additional miscellaneous automatic information. However, these extra mechanical layers are not required for the majority of printed circuit boards.
2、Layer Stack Up (Distinguish With PCB Layers)
2.1 What Is Layer Stack Up?
A layer stack up is the proper placement of a type of layer. PCB’s are in general categorized into three:
• Single layers.
• Double layers.
The above terms describe the number of copper layers in a PCB. The multi-layer PCB describes those that have more than two layers which may be in the range of 4, 6 and 8.
In a multi-layer, the top and bottom layers are known as outer layers while those in between are known as inner layers. The complexity in the manufacture of multi-layer PCB’s makes them quite costly when compared to the double and single layer PCB’s.
In layer stack up, there are a few things that you can put into consideration, and these include the following:
• The substrate material.
• The PCB layers order.
• The copper thickness.
Different designs of circuits have different layer stack-ups that suite them appropriately. Layer stack up is essential in the functioning of the Printed Circuit Boards.
Different problems may arise when a layer stack up is not well planned, and such include:
• Signals crosstalk.
• Electromagnetic interferences.
• Signal dissipation.
To avoid the above problems and even more, it is vital to have a well-planned PCB layer stack up. You can save a lot by designing efficient PCB layer stack up which can go a long way in preventing possible issues that may arise due to the improper design.
In Layer Stackup other than the PCB layers order, substrate material, copper thicknesses are also considered.
There are different layer stacks for different types of circuit designs. A well planned PCB layer stack ensures the best performance of the PCB such as decreasing the electromagnetic interferences, signals crosstalk, coupling, overshoot and undershoot, and signal dissipation.
The design to be completed and qualified first time means that it can reduce costs and the design cycle time significantly. It is possible if the signal integrity issues are eliminated before they arise.
In figure 1 below two 8-layer, stack up schemes are shown that emphasize the changing order of layers.
Other than signal layers, power planes do also play a vital role in successful product development.
The signals either digital or analog are possible to route through microstrip lines or strip lines that reduce crosstalk and consequently improve signal integrity.
The low-frequency signals are routed on the inner layers whereas the high-frequency signals are routed on the outer layers.
It is a good practice to place a ground plane layer adjacent to each signal layer, however, to reduce layer stack up and manufacturing cost the ground layer is placed after each two signal layers. The power planes should also be adjacent to the ground planes that make the tight coupling.
The power planes are split into more than one part in the case of multiple power supply rails. Usually, the PCB thickness is 1.6mm, but it is challenging to maintain 1.6mm thickness in case of more than 12 layers PCB.
In figure 1 below two 8-layer, stack up schemes is shown that emphasize the changing order of layers.
In figure 2 10-layer PCB Stackup scheme is described.
2.2 Distinguishing PCB Layers From Layer Stack Up
As much as these two terms may seem to mean the same thing, this is entirely not the case. A layer stack up as defined above is the proper placement of a type of layer.
On the other hand, PCB layers refer to copper layers given in a certain quantity and order. Whereas layer stack up is concerned with the planning of layers, PCB layers are concerned with the amount and order of layers.
3、PCB Layers Types
3.1 1-Layer PCB
Often referred to as a single layer PCB, the one layer PCB is printed from one side, this implies that the PCB sheet is on one side together with a conductive material while on the other side electronic components are connected.
At first, all the PCB's were being designed manually, but due to technological advancements, they can now be created using specialized software such as eagle PCB software. It is done through the use of computers that have this program.
Single layer PCB’s come in different types. Some of them include the following:
• Flexible PCB’s. These single layer PCB’s are made out of flexible material instead of the rigid ones. Such materials that can be used in this case include plastics. The cost of production for this type of single layer PCB is quite high making it uneconomical.
• Rigid PCB's. These single layer PCB's are made out of rigid material such as fiberglass. They are not flexible and thus cannot allow for the circuit to bend. They are commonly used in most devices such as calculators, power supplies et al.
• High-frequency PCB'S. These single layer PCB's are used in circuits that require significantly high frequencies to operate. In choosing the right material to be used for such PCB's, thermal expansion, water absorption, and dielectric loss are some of the factors that are put into the account.
• Rigid-flex PCB's. These single layer PCB's are made out of a combination of plastic and fiberglass. Both the two materials are combined into a single layer. This combination reduces the size and weight of the PCB consequently.
• Aluminum backed PCB's. These single layer PCB's are made out of aluminum material. The design of this PCB is almost similar to that of the copper one only that the difference occurs in the article that has been used.
One layer PCB's are quite simple as you can see. However, let not their simplicity fool you for what they can achieve. They might be simple, but they produce much regarding working in complex devices. There are some functions that they perform and some of them include the following:
• They are used in radio and stereo equipment’s circuits.
• They are used in digital cameras.
• They are used in photocopy and printer machines.
• They are used in digital calculators.
• They are used in vending machines.
The single layer PCB's have some advantages for instance:
• Easy to come up with and design.
• Easy to install.
• Cost effective.
• It is easily understandable.
• There are low probabilities of short-circuiting.
• More reliable and efficient.
3.2 2-Layers PCB
A two-layer PCB is also called a double-layer or double-sided PCB. It is mainly made of an FR-4 glass epoxy substrate laminated with thin copper film or layers on both sides. It is the simplest and the most economical PCB to design.
A two-layer PCB can easily be manufactured by a professional PCB Prototyping factory (e.g., wellpcb.com), and can also be made at home. Two layer PCB has only the top and the bottom copper layers.
It is a simple design to come up with not forgetting how economical it is too. This PCB design can easily be manufactured at home with the right software. It is mostly just made with PCB prototyping companies.
The PCB layers in this design are mainly the signal layer which forms the top layer and the bottom layer that is made up of electrical components. All the components of a double layer PCB are as follows:
• PCB layers that include the silk layer, the top, and the bottom layer.
• Solder mask.
There are some places in which double layer PCB's are used. Some of the areas of application include the following:
• In lighting. The double layer PCB’s are used in LED lights and thus the power they have.
• In medical devices. Double layer PCB’s are utilized in medical equipment such as pacemakers and CAT check machines.
• Automotive and aerospace industries. In both the car industry and the aviation one, PCB's are in significant use. The double-sided PCB's to be more precise are used majorly in these two industries.
Double layer PCB’s come with a wide range of advantages. You can take a look at some of them below:
• They make laying of tracks simpler.
• Permit higher thickness in segments.
• Offer expanded warmth scattering.
3.3 4-Layers PCB
A four layer PCB has four copper layers. The top and bottom layers are the routing layers while the two layers sandwiched between are the power and ground planes.
Between the Four-layer, PCB Copper layers are the Core and the Prepreg. During manufacture, all these elements are brought together (sandwiched) by a laminate under high heat and pressure to ensure that the whole stack-up is held together in place.
The four-Layer PCB can contain through vias, blind vias and buried vias. For a four-Layer PCB, buried via can only be between the second and the third layer and the blind vias can be between the top (first) and the second layer or between the bottom (forth) and the third layer.
The typical stack-up for a four layer board would be power & ground for the inner two layers, and then the signals on the outer two layers. One usually would route the two signals layers perpendicularly.
It's not as critical if the layers are separated by power and ground, but if you have signals on adjacent layers, it becomes more important so that you minimize crosstalk.
As for numbering one usually goes from 1 to n starting at the top going down to the bottom. This is the only convention, you can do whatever you like, as you'll provide the stack-up info when you send the files for production.
In the manufacture of a four-layer PCB, the cost can be quite useful in case you have a manufacturing plant.
3.4 6-Layers PCB
The design that makes the six-layer PCB is immune and quiet. There are some reasons why the six-layer PCB is advantageous as compared to the others. Some of the ideas include the following:
• The tracing that is in between the third and first layer doesn’t require any special treatment.
• Every trace has proximity to the ground.
3.4.1 Reference Plane
The reference plane is used for transferring return current. In the four-layer design, layer one has a high-frequency return currency on the second layer, and the fourth layer also has a high frequency on the third layer hence there is no difference with the six-layer PCB.
When the reference planes are moved closer to the routing or signal layers you will have cut up on the loop area that determines the emissions that are radiated and the susceptibility when in high frequency.
The following are some of the factors that make the six-layer stack to work well.
1. The proximity to the ground by every trace.
2. The proximity of ground planes and power that creates the planner capacitance.
3. The tracing between the third and first layers which does not require any special treatment.
4. The layer four reference plane is higher than the distance that between it and layer 2.
3.4.2 The Common 6 Layer PCB Stack-Up Design
The best six-layer PCB design will require stitching to connect two ground planes found in the PCB which in turn are supposed to return the current to the reference planes. Some people say that adding extra ground planes helps in shielding against emissions and immunity.
3.4.3 PCB Plane Cuts Kill EMC
The plane cuts can be devastating to the EMC in both emissions and susceptibility. Plane cuts or voids is when the power or the ground plane has an unintentional or intentional cut through a given portion of a plane. The plane cuts come in different sizes and shapes.
A current return path on the plane is some few thousand inches away, and in good designs, the trace runs adjacent to the plane hence making the return current path to be nearby thus forming the loop area to be relatively small.
When you introduce some void in the copper plane layer, you will have to create a loop that will be required for trace running across the voids and plane cuts. It makes the current loop area to be much more significant.
3.5 8-Layers PCB
An eight-layer board can be used to add two more routing layers or to improve EMC performance by adding two more planes.
The percentage increase in the cost of an eight-layer board over a six-layer board is less than the percentage increase in going from four to six layers, hence making it easier to justify the cost increase for improved EMC performance.
Therefore, most eight-layer boards consist of four wiring layers and four planes.
In general, to make an Eight-layer PCB, you need alternating layers of the copper layer, prepreg, and core. The prepreg acts as the glue that firmly combines the Eight-layer PCB stack-up into a single board.
Following the rules to improve the electromagnetic compatibility, a simple Eight-layer PCB configuration would look as shown below. It is important to note that an Eight-Layer PCB is capable of achieving high signal integrity as compared to 6-layer PCB and below.
You can choose the PCB stack-up design method according to the number of signal networks, device density, PIN density, signal frequency, board size. The higher the number of signal networks, the higher the device density, the higher the PIN density, and the higher the signal.
Besides, for good EMI performance, it is best to ensure that each signal layer has its reference.
Some advantages come with using an eight-layer PCB. Some of the pros and benefits include the following:
• It reduces the electromagnetic interference which may lead to interruptions.
• It improves signal integrity.
3.6 Multilayer PCB
3.6.1 32 Layers PCB
It is merely a multilayer PCB that is made up of 32 layers. The layers are put together to work as a single PCB. These PCB layers are advanced and thus require to come up with skills and precisions.
Every design of a PCB starts with the software. For a 32 layer PCB, a stack up is made which contains many PCB layers. It is made possible through the use of a machine that sandwiches the layers together.
There are some reasons as to why you can choose to use the 32 layer PCB. Some of the ideas include the following:
• Used in aerospace systems.
• Used in the automotive field.
Technique Behind 32 Layer PCB
To manufacture a 32 Layer PCB, a Stack-Up made up of multiple PCB layers is constructed.
It is made possible by the machine; sandwiching various double layer PCBs with the help of an insulating fiber-epoxy layer in between every two double layer PCB. This insulating material is also called prepreg.
It implies that the basic building blocks of any multilayer PCB are a double layer PCB.
With this two-sided PCB fabrication technique at hand, and with more advanced machines to handle the increased complexity, fabrication of a 32 Layer or even a 50 Layer PCB is well achievable.
32 Layer PCB Applications
Why do we need these 32 or 50 Layer PCBs? One of the obvious reasons is to efficiently embed all the necessary system electronics in one small sized PCB.
Even though components assembly is dedicated to top and bottom layers, it is possible to have components in between the Stack-up. Aerospace industry does an excellent job in making these complex PCB designs.
In any aerospace system, the target is to have very little or no electromagnetic emission as possible. Organizing a PCB during the design phase does a great job in arresting these emissions.
Each PCB layers is usually dedicated to a specific function which is not conflicting with other layers. For example, middle layers could be used as supply power planes, while the top and bottom layers are set aside for component placement.
3.6.2 Multilayer PCB
Multilayer PCB's have an unlimited number of conducting layers. The help of insulating layers then separates the layers. They are usually made up on the inside of the double-sided boards. The outer layers are generally made up of single-sided boards.
The manufacturers of the multilayer PCB's make use of heat and pressure to bond each of the PCB layers to form one PCB board. Any PCB that has more than two layers can be classified as a multilayer PCB.
It stack-up must be made in such a way that, the complete board shall meet the electrical signal and power needs and also meet the mechanical strength requirements. Most professional PCB designs can exhibit around 15dB fewer emissions.
There are some reasons as to why you should consider using a multilayer PCB over the single or double sided PCB's. Some of these reasons include the following:
• They result in high quality and reliable products.
• They have a higher density of assembly.
• Increases functionality.
When making a multilayer PCB, you must plan about the configuration of your PCB stack-up. Wrong PCB configuration may give rise to undesired electromagnetic interference and poor signal integrity.
Below are some of the essential things to consider about signal when making a multilayer PCB design.
• Consider the type of signals to be routed, e.g., different signal frequencies
• Consider the signal rise and fall
• Sufficient return for the signal loop
Likely signal delay caused by permittivity - Possible cross-connection and overlap
A circuit that has more than two layers is known as a multilayer PCB. Therefore this is to imply that the minimum number of PCB layers that should be present for a multilayer PCB is three. Laminating the materials together is not easy but is necessary for multilayer pool.
A multilayer pool should have no air that is trapped in between. In the manufacture of the multilayer pool, the Eagle PCB design software is necessary.
The process is complicated and as usual starts with the preparation of a schematic diagram. The schematic is then edited by the use of the editor menu that is on the Eagle software.
You may wonder why most PCB layers are even. It is important to note that it is more cost effective to prepare even layers than odd ones. This is, therefore, the contributing reason for the layers being even.
4.1 Multilayer PCBs
In making multilayer PCBs, both the core and prepreg materials are used in making the layers. Prepreg materials are those that are not cured meaning that they are malleable.
Alternative materials of both prepreg and core are then laminated together under high temperatures, and pressure, which makes the prepreg material to melt and the layers are joined together after cooling off and results in a hard and solid multilayer board.
Notice that the multilayer PCB comes with a wide range of advantages that includes:
• Increased flexibility
• Higher assembly density
• Controlled impedance features
• Small in size
• Have an EMI shielding
• Eliminates the need to interconnect harnesses which reduces the overall weight
4.2 Multilayer Pool Process
Multiple PCB making process involves using Eagle software in designing PCBs. It is a complicated procedure that starts with completing a Schematic diagram. The schematic is edited through the editor menu through Eagle software.
4.3 Multilayer Pool
After designing and drawing the schematic diagram, the next thing that needs to be done is to work out on the layout; This could be done by bringing the dimension of your printed circuit board and uploading it onto a software.
If you are using the Eagle software, you will have the opportunity to choose appropriate grid to help each layer of your PCB to overlap on each other; This could be done using a button that routes each of the layers separately as per your needs.
Alternatively, you can make the multilayer pool for the PCB by auto-creating it using the Eagle software. However, if you choose this technique, it will be necessary that you cross check the components, text, layers, and dimensions.
You should then use the check rule option to evaluate the final layout.
4.4 Multilayer Circuit Boards
Multilayer printed circuit boards have become the core of the world’s electronics. They are the essential functions of components and wiring; This has made the new PCBs more advanced and sophisticated.
It gives the final users advanced flexible options and oddly shaped varieties to choose it. PCBs for simple electronics consist of a single layer while sophisticated PCBs such as those used in computer motherboard are made up of multiple layers, This is why they are referred to as multilayer PCBs.
It is important to note that the advanced technology has allowed manufacturers to downsize PCBs significantly.
Multilayer PCBs are the PCBs made with at least three copper foil layers. They appear like several single or double-sided PCBs which are glued together with heat and protective insulation. The two layers are customarily placed on the surface side of the PCB.
Electrical connections in the layers are achieved through vias like buried vias and plating through the holes; This is what results in a generation of complex PCBs that you will get on the market which comes in varying sizes.
Multilayer PCBs were discovered through changes that were taking place in the world of electronics. Their continued use and function in the modern world of electronics have made them more complex and sophisticated.
Initially, PCBs had their problems including crosstalk, capacitance, and noise. As a result, it was necessary that manufacturers had to come up with specific constraints to limit the issues.
The design consideration meant that it was prudent to design PCBs that would result in high levels of performance hence the double-sided PCB and so forth. It is this understanding that resulted in the discovery of multilayer PCBs.
It allowed for the packing of multilayer PCBs into small sizes to accommodate the ever-increasing needs of electronics.
The modern PCBs have various layers that range from 4-12 layers. The sheets come in even numbers to reduce issues such as warping which is associated with an odd number of layers.
Also, it is cost-effective to produce an even number of layers compared to building a different number of layers.
Moreover, most of the modern devices that include smartphones and mobile devices use PCBs with 12 sheets. Some manufacturers can manufacture PCBs with about 32 layers.
Notice that while it is labor intensive and expensive to manufacturer multilayer PCBs, they are becoming important in the modern world.
The reason for this is that they come with a host of benefits than what you would get with a double or single layer PCBs.
4.5 Advantages of Multilayer PCBs
They are small in size; this is the most excellent feature of multilayer PCBs. They are smaller than the single or double layer PCBs, and this has resulted in a significant benefit to the current trends.
They are more compact, robust and find much application in laptops, smartphones, and tablets. They are lightweight in construction.
The smaller PCBs are less weighty since they don't make use of multiple connectors that require them to be interlinked to double layered and single PCBs this increases the mobility of the devices in which applied.
• High quality. Creating a multilayer PCB requires proper planning and organization meaning that the result will be products, which are better in quality compared to the double or single layer PCBs. Also, these PCBs are more reliable.
• Increased durability. Multi-layer PCBs are durable. They can withstand much weight and are capable of handling heat and pressure that is always applied to them during binding. They also have multiple layers of insulation material between the individual layers and prepreg bonding agent that increases their durability.
• Highly flexible.PCB assemblers that use flexible construction techniques end up with flexible multilayer PCBs, which have highly desirable features such as the ability to be applied in areas where flexing and bending will be required. However, it is important to note that the more the layers used in a PCB, the less flexible it is.
• More powerful. The multilayer PCBs incorporates many layers into a unit PCB, and so they enable the board to be more connective giving them properties that allow them to achieve higher speed and capacity even though they are small sized.
• Single connection point. The multilayer PCBs work in a singular unit, and so they will always have just a single connection point which is not the case when you use several single or double layered PCBs, This is of significant benefits to the electronic world as it helps to minimize the size and weight.
1. Even though we have talked much about the benefits of multilayer printed circuit boards, it is critical that they come with a few problems.
2. They are costly compared to single layer PCB because of the complicated manufacturing process and an extensive amount of time taken to construct them. This increases the labor cost which translates to high prices of PCBs.
3. They are more challenging to manufacture and require a lot of time and advanced manufacturing techniques than the single-layered PCBs because any small flaws could make them useless.
4. The supply is limited- because they need expensive machinery to manufacture, very few manufacturers can produce them, and so, their production is limited.
5. Require extensive design and interconnection between the layers and one should be able to mitigate impedance issues and crosstalk. Any single mistake can lead to non-functioning of the board.
6. Manufacturing the PCB requires plenty of time and person-hours, and so it is sometimes difficult to deliver orders within the specified timeframes.
4.7 How Multilayer PCBs Compare With Single Layer PCBs
1. They are of high density and greater functionality because layering increases their capacity and speed.
2. They are small sized since the addition of layers increases their surface area meaning that you will have a high ability of PCB compared to what you can get in single layer PCB.
3. They are light in weight since it requires fewer connectors and can be used in complex electrical applications.
4. The multilayer PCBs have enhanced functionality compared to single layers and have great EMI shielding, controlled impedance, and more feature despite their small size.
Multilayer PCBs can be put to just any use and have become a preferred option because they can be used across all technologies.
They are found in almost all electronics including smartphones, microwaves and other domestic consumer equipment. They are also used in smartwatches and mobile devices because they are small in size and have increased functionality.
In computer electronics, they find much application in the motherboards and servers. Their space-saving feature makes it easier for them to be applied widely in the technology industry.
Multilayer PCBs are also widely applied in telecommunication devices. They are used in GPS, signal transmission as well as in satellite applications. Because they are durable, can easily be used in tower outdoors and mobile devices as well.
In industries, multilayer PCBs are quite vital because they are small in size and durable. They are therefore widely applied in industrial control and are used in running machinery in industrial applications.
The medical field has also benefited greatly from PCBs. They are found in equipment that is used in diagnosis as well as those that are used in treatment.
They are small in size lightweight, and so they can be used in heart monitors, x-ray, medical testing devices and CAT scan equipment.
The military has also benefited a lot from multilayer PCBs. They are deployed in high-speed circuits, and so they are highly utilized in military applications. They are also used in devices that require increased movement.
The automotive industry especially the electric car has also significantly benefited from PCBs. They are used in GPS’s headlight switches and engine sensors.
They are small durable and heat-resistant, a thing that makes them entirely applicable in the automobile environment.
4.9 Multilayer Pool Technology
The technology has allowed the production of quality board and is considered key to success in military, communication and other fields that rely on multilayer PCBs.
The technology enables the manufacturers to fabricate PCBs from materials such as flex, Teflon, and polyimide allowing the customers to fulfill their PCB needs.
4.10 Multilayer Pool Switch
PCBs play a vital role in the manufacturing of computer networking devices such as multilayer switch which provides extra function including routing capability. The switch can prioritize the packets and implement QoS differentiated services in hardware.
4.11 Multilayer Pool Ceramic Capacitor
They are popularly referred to as MLCCs and are used in building blocks in the modern electronics. MLCCs make up of more than 30% of the components in the hybrid circuit module.
They consist of monolithic ceramic block with electrodes that appear on the surface end of the ceramic block that forms the contact which is made by having burnt in metallic layer.
MLCCs come in different kinds that include those that are described as tolerance, capacitance, and dielectric, case size and so forth. Their values vary, but the most common ones range from 10 nF to 1µF. Also, their voltage rating ranges from 16V to 100V.
As technology advances, more and more multilayer PCBs are produced. These PCBs are finding much application in both the research industry and science. They are used in security appliances, alarm systems as well as fiber optic sensors.
They are also used in weather analysis equipment and atomic accelerators. They multilayer PCBs are becoming light-weighted, compact and save on spaces.
5、PCB Layers Thickness
Different PCB layers have the different thickness depending on where they will be applied. For instance:
• 11 layer boards can be of 20 by 14 dimensions unless given additional specifications.
• Six layer boards are produced on a thickness of 0.031, 0.040, 0.047, 0.062 and 0.125 inches.
• Both the 8 and ten layer boards can be found with the thickness of 0.062, 0.093 and 0.125 inches.
The standard pooling thickness for multilayer PCB’s is 1.55mm. This standard measurement is not the actual measurement for all the multilayer PCB’s but can be used as a reference in their construction.
6、Pcb Layers Ordering
PCB layers are arranged in orders. The process of organizing these layers can be as follows:
• Choosing the initial number of layers. Here you will select the PCB layers that will suit the need you want to achieve. If it is for home prototyping, then one or two layers can be quite useful. Four layers PCB's are simple or rather cheap boards.
Six-layer PCB's are cheap and abundant. Eight-layer PCB's are quite cost effective while the 12 layers PCB's are ideal for heavy industry boards or just boards that have many tracks.
• Starting the layout
• Here you will begin with the top and bottom signal layers. Depending on the design that you are using, the two top and bottom signals would be just enough unless you have too many connections that would require inner signal layers also.
There are some options that you can use to order your PCB layers. The following are some of the most common ones:
• Four layer stack up.
• Six layer stack up.
• Eight-layer stack up.
• Ten layer stack up.
• 12 layer stack up with two additional signal layers.
• 12 layer stack up with 4 GND’s.
You can make a quote of the type of PCB you would want here https://www.wellpcb.com/pcb-quote
As you have seen, PCB layers make up different designs of Printed Circuit Boards for various appliances. Depending on where you would want to use the PCB's, the sheets would vary.
The single and double-sided layers are cheaper to construct but do not perform the complex operations that the multilayer PCB's can do. The multilayer PCB's are used in more advanced machines and electronics as compared to the others.
The multilayer PCB's are made out of three or more PCB layers which are formed of copper among other materials. In case of any inquiries and issues, you can contact us through the following: