Serving You a World-Class 4-Layer PCB
PCBTok is a versatile PCB maker. We’re capable of making all types of PCBs for you.
- Competent in making single- double- and multilayer PCBs like the 4-Layer PCB
- We even offer complete cables assembly and PCBA solutions
- Your peace of mind guaranteed with extensive PCB test deployed
- 100% AOI inspection and other advanced manufacturing methods
Ask our sales representatives about 4-Layer PCB for further details.
Best-Value 4 Layer PCB
Announcing our product offering: the 4-Layer PCB.
Any 4 Layer PCB requirements you may have can be met by us.
Over 12 years have passed since our seasoned support team has joined us. As w result, it is without a doubt, our team are experts in multilayer circuit boards of this kind.
We want to offer a free sample to make sure you are satisfied with your orders for 4 Layer PCB.
You are entitled to this if you have a bulk purchase order. Please inquire!
We feature all the details you ever need in this piece so you don’t need to worry about complete info about 4-Layer PCB products!
4-Layer PCB By Feature
4-Layer PCB By Board Type (6)
4-Layer PCB By Thickness & Surface Mount (5)
4 Layer PCB Benefits
PCBTok can offer 24h online support for you. When you have any PCB-related questions, please feel free to get in touch.
PCBTok can build your PCB prototypes quickly. We also provide 24 hour production for quick-turn PCBs at our facility.
We often ship goods by international forwarders such as UPS, DHL, and FedEx. If they are urgent, we use priority express service.
PCBTok has passed ISO9001 and 14001, and also has USA and Canada UL certifications. We strictly follow IPC class 2 or class 3 standards for our products.
Offering Effective 4 Layer PCB Products
We deal with a lot of companies who get us as their OEM producer for 4 Layer PCB.
With us, your product is protected from device failure situations by our strong Quality Control guarantee.
We want to prevent this bad situation because it does not speak highly of us as your PCB supplier.
Pick the 4-Layer PCB from PCBTok and other related products right away.
Don’t pass up this fantastic opportunity!
We are your competent 4 Layer PCB fabricator.
Dependably Amazing 4 Layer PCB Process
Consumers trust the 4 Layer PCB manufactured by us.
As a veteran in the industry, we are well-versed in what it takes to produce top-notch PCBs
We adhere to the standards when performing Material Handling, IQC, Reflow, In-Circuit Test (ICT)—
As well as the other detailed PCB manufacturing processes.
If in doubt, contact us, and we will explain it all. We’re always here to help with your 4 Layer PCB item.
Conquer With Our 4 Layer PCB Support
You’re right to check us up if you’re looking for a reputable Chinese manufacturer of PCBs.
At PCBTok, we provide high-quality 4-Layer PCB without the excessive cost.
As it is our mission to lead the PCB industry, we never compromise on PCB quality.
If you work with us as a partner, we’ll help your brand expand.
Conquer your difficulties, don’t use unreliable PCB suppliers.
We won’t let you down with our excellent products.
The Reliable Option: PCBTok’s 4 Layer PCB
We are the PCB makers you can rely on to deliver your 4 Layer PCB without delay!
- Our company shows advantages, which include:
- Quick-turn processing of your 4-Layer PCB order
- Highly updated facilities
- A well-trained workforce, particularly in communication
- Transparent work-flow process with WIP if you desire
4 Layer PCB Fabrication
We are the best in 4-Layer PCBs because we have a lot of PCB industry experience.
Our goal is to support the expansion of your business.
We consider the long term goal since, if we are successful in modest 4-Layer order fulfillment, it will signify that we can be your long-term partner for you.
We can be your dedicated OEM or EMS companion.
Simple PCBs like single-sided and double-sided have long been the only options available to hobbyist PCB designers.
But with us, PCBTok, you are free to explore with the 4-Layer PCB option.
We welcome any and all PCB designs. The more innovative, the better.
Because we don’t have a minimum order quantity for this kind of PCB,
Kindly inquire now! You will be surprised by the possibilities.
OEM & ODM 4 Layer PCB Applications
4 Layer PCB Production Details As Following Up
|1||Layer Count||1-20 layers||22-40 layer|
|2||Base Material||KB、Shengyi、ShengyiSF305、FR408、FR408HR、IS410、FR406、GETEK、370HR、IT180A、Rogers4350、Rogers400、PTFE Laminates(Rogers series、Taconic series、Arlon series、Nelco series)、Rogers/Taconic/Arlon/Nelco laminate with FR-4 material(including partial Ro4350B hybrid laminating with FR-4)|
|3||PCB Type||Rigid PCB/FPC/Flex-Rigid||Backplane、HDI、High multi-layer blind&buried PCB、Embedded Capacitance、Embedded resistance board 、Heavy copper power PCB、Backdrill.|
|4||Lamination type||Blind&buried via type||Mechanical blind&burried vias with less than 3 times laminating||Mechanical blind&burried vias with less than 2 times laminating|
|HDI PCB||1+n+1,1+1+n+1+1,2+n+2,3+n+3(n buried vias≤0.3mm),Laser blind via can be filling plating||1+n+1,1+1+n+1+1,2+n+2,3+n+3(n buried vias≤0.3mm),Laser blind via can be filling plating|
|5||Finished Board Thickness||0.2-3.2mm||3.4-7mm|
|6||Minimum Core Thickness||0.15mm(6mil)||0.1mm(4mil)|
|7||Copper Thickness||Min. 1/2 OZ, Max. 4 OZ||Min. 1/3 OZ, Max. 10 OZ|
|9||Maximum Board Size||500*600mm(19”*23”)||1100*500mm(43”*19”)|
|10||Hole||Min laser drilling size||4mil||4mil|
|Max laser drilling size||6mil||6mil|
|Max aspect ratio for Hole plate||10:1（hole diameter＞8mil）||20:1|
|Max aspect ratio for laser via filling plating||0.9:1(Depth included copper thickness)||1:1(Depth included copper thickness)|
|Max aspect ratio for mechanical depth-
control drilling board(Blind hole drilling depth/blind hole size)
|0.8:1(drilling tool size≥10mil)||1.3:1(drilling tool size≤8mil),1.15:1(drilling tool size≥10mil)|
|Min. depth of Mechanical depth-control(back drill)||8mil||8mil|
|Min gap between hole wall and
conductor (None blind and buried via PCB)
|Min gap between hole wall conductor (Blind and buried via PCB)||8mil(1 times laminating),10mil(2 times laminating), 12mil(3 times laminating)||7mil(1 time laminating), 8mil(2 times laminating), 9mil(3 times laminating)|
|Min gab between hole wall conductor(Laser blind hole buried via PCB)||7mil（1+N+1）；8mil（1+1+N+1+1 or 2+N+2）||7mil（1+N+1）；8mil（1+1+N+1+1 or 2+N+2）|
|Min space between laser holes and conductor||6mil||5mil|
|Min space between hole walls in different net||10mil||10mil|
|Min space between hole walls in the same net||6mil(thru-hole& laser hole PCB),10mil(Mechanical blind&buried PCB)||6mil(thru-hole& laser hole PCB),10mil(Mechanical blind&buried PCB)|
|Min space bwteen NPTH hole walls||8mil||8mil|
|Hole location tolerance||±2mil||±2mil|
|Pressfit holes tolerance||±2mil||±2mil|
|Countersink depth tolerance||±6mil||±6mil|
|Countersink hole size tolerance||±6mil||±6mil|
|11||Pad(ring)||Min Pad size for laser drillings||10mil(for 4mil laser via),11mil(for 5mil laser via)||10mil(for 4mil laser via),11mil(for 5mil laser via)|
|Min Pad size for mechanical drillings||16mil(8mil drillings)||16mil(8mil drillings)|
|Min BGA pad size||HASL:10mil, LF HASL:12mil, other surface technics are 10mil(7mil is ok for flash gold)||HASL:10mil, LF HASL:12mil, other surface technics are 7mi|
|Pad size tolerance(BGA)||±1.5mil(pad size≤10mil);±15%(pad size>10mil)||±1.2mil(pad size≤12mil);±10%(pad size≥12mil)|
|1OZ: 3/4mil||1OZ: 3/4mil|
|2OZ: 4/5.5mil||2OZ: 4/5mil|
|3OZ: 5/8mil||3OZ: 5/8mil|
|4OZ: 6/11mil||4OZ: 6/11mil|
|5OZ: 7/14mil||5OZ: 7/13.5mil|
|6OZ: 8/16mil||6OZ: 8/15mil|
|7OZ: 9/19mil||7OZ: 9/18mil|
|8OZ: 10/22mil||8OZ: 10/21mil|
|9OZ: 11/25mil||9OZ: 11/24mil|
|10OZ: 12/28mil||10OZ: 12/27mil|
|1OZ: 4.8/5mil||1OZ: 4.5/5mil|
|1.43OZ（negative ）:5/8||1.43OZ（negative ）:5/7|
|2OZ: 6/8mil||2OZ: 6/7mil|
|3OZ: 6/12mil||3OZ: 6/10mil|
|4OZ: 7.5/15mil||4OZ: 7.5/13mil|
|5OZ: 9/18mil||5OZ: 9/16mil|
|6OZ: 10/21mil||6OZ: 10/19mil|
|7OZ: 11/25mil||7OZ: 11/22mil|
|8OZ: 12/29mil||8OZ: 12/26mil|
|9OZ: 13/33mil||9OZ: 13/30mil|
|10OZ: 14/38mil||10OZ: 14/35mil|
|13||Dimension Tolerance||Hole Position||0.08 ( 3 mils)|
|Conductor Width(W)||20% Deviation of Master
|1mil Deviation of Master
|Outline Dimension||0.15 mm ( 6 mils)||0.10 mm ( 4 mils)|
|Conductors & Outline
( C – O )
|0.15 mm ( 6 mils)||0.13 mm ( 5 mils)|
|Warp and Twist||0.75%||0.50%|
|14||Solder Mask||Max drilling tool size for via filled with Soldermask (single side)||35.4mil||35.4mil|
|Soldermask color||Green, Black, Blue, Red, White, Yellow,Purple matte/glossy|
|Silkscreen color||White, Black,Blue,Yellow|
|Max hole size for via filled with Blue glue aluminium||197mil||197mil|
|Finish hole size for via filled with resin||4-25.4mil||4-25.4mil|
|Max aspect ratio for via filled with resin board||8:1||12:1|
|Min width of soldermask bridge||Base copper≤0.5 oz、Immersion Tin： 7.5mil(Black), 5.5mil(Other color) , 8mil( on copper area)|
|Base copper≤0.5 oz、Finish treatment not Immersion Tin ： 5.5 mil(Black,extremity 5mil), 4mil(Other
color,extremity 3.5mil) , 8mil( on copper area
|Base coppe 1 oz: 4mil(Green), 5mil(Other color) , 5.5mil(Black,extremity 5mil),8mil( on copper area)|
|Base copper 1.43 oz: 4mil(Green), 5.5mil(Other color) , 6mil(Black), 8mil( on copper area)|
|Base copper 2 oz-4 oz: 6mil, 8mil( on copper area)|
|15||Surface Treatment||Lead free||Flash gold(electroplated gold)、ENIG、Hard gold、Flash gold、HASL Lead free、OSP、ENEPIG、Soft gold、Immersion silver、Immersion Tin、ENIG+OSP,ENIG+Gold finger,Flash gold(electroplated gold)+Gold finger,Immersion silver+Gold finger,Immersion Tin+Gold finge|
|Aspect ratio||10:1(HASL Lead free、HASL Lead、ENIG、Immersion Tin、Immersion silver、ENEPIG);8:1(OSP)|
|Max finished size||HASL Lead 22″*39″；HASL Lead free 22″*24″；Flash gold 24″*24″；Hard gold 24″*28″；ENIG 21″*27″；Flash gold(electroplated gold) 21″*48″；Immersion Tin 16″*21″；Immersion silver 16″*18″；OSP 24″*40″；|
|Min finished size||HASL Lead 5″*6″；HASL Lead free 10″*10″；Flash gold 12″*16″；Hard gold 3″*3″；Flash gold(electroplated gold) 8″*10″；Immersion Tin 2″*4″；Immersion silver 2″*4″；OSP 2″*2″；|
|PCB thickness||HASL Lead 0.6-4.0mm；HASL Lead free 0.6-4.0mm；Flash gold 1.0-3.2mm；Hard gold 0.1-5.0mm；ENIG 0.2-7.0mm；Flash gold(electroplated gold) 0.15-5.0mm；Immersion Tin 0.4-5.0mm；Immersion silver 0.4-5.0mm；OSP 0.2-6.0mm|
|Max high to gold finger||1.5inch|
|Min space between gold fingers||6mil|
|Min block space to gold fingers||7.5mil|
|16||V-Cutting||Panel Size||500mm X 622 mm ( max. )||500mm X 800 mm ( max. )|
|Board Thickness||0.50 mm (20mil) min.||0.30 mm (12mil) min.|
|Remain Thickness||1/3 board thickness||0.40 +/-0.10mm( 16+/-4 mil )|
|Tolerance||±0.13 mm(5mil)||±0.1 mm(4mil)|
|Groove Width||0.50 mm (20mil) max.||0.38 mm (15mil) max.|
|Groove to Groove||20 mm (787mil) min.||10 mm (394mil) min.|
|Groove to Trace||0.45 mm(18mil) min.||0.38 mm(15mil) min.|
|17||Slot||Slot size tol.L≥2W||PTH Slot: L：+/-0.13(5mil) W：+/-0.08(3mil)||PTH Slot: L：+/-0.10(4mil) W：+/-0.05(2mil)|
|NPTH slot(mm) L+/-0.10 (4mil) W：+/-0.05(2mil)||NPTH slot(mm) L：+/-0.08 (3mil) W：+/-0.05(2mil)|
|18||Min Spacing from hole edge to hole edge||0.30-1.60 (Hole Diameter)||0.15mm(6mil)||0.10mm(4mil)|
|1.61-6.50 (Hole Diameter)||0.15mm(6mil)||0.13mm(5mil)|
|19||Min spacing between hole edge to circuitry pattern||PTH hole: 0.20mm(8mil)||PTH hole: 0.13mm(5mil)|
|NPTH hole: 0.18mm(7mil)||NPTH hole: 0.10mm(4mil)|
|20||Image transfer Registration tol||Circuit pattern vs.index hole||0.10(4mil)||0.08(3mil)|
|Circuit pattern vs.2nd drill hole||0.15(6mil)||0.10(4mil)|
|21||Registration tolerance of front/back image||0.075mm(3mil)||0.05mm(2mil)|
|22||Multilayers||Layer-layer misregistration||4layers:||0.15mm(6mil)max.||4layers:||0.10mm(4mil) max.|
|Min. Spacing from Hole Edge to Innerlayer Pattern||0.225mm(9mil)||0.15mm(6mil)|
|Min.Spacing from Outline to Innerlayer Pattern||0.38mm(15mil)||0.225mm(9mil)|
|Min. board thickness||4layers:0.30mm(12mil)||4layers:0.20mm(8mil)|
|Board thickness tolerance||4layers:+/-0.13mm(5mil)||4layers:+/-0.10mm(4mil)|
|8-12 layers:+/-0.20mm (8mil)||8-12 layers:+/-0.15mm (6mil)|
|26||Impedance control||±5ohm(＜50ohm), ±10%(≥50ohm)|
PCBTok offers flexible shipping methods for our customers, you may choose from one of the methods below.
DHL offers international express services in over 220 countries.
DHL partners with PCBTok and offers very competitive rates to customers of PCBTok.
It normally takes 3-7 business days for the package to be delivered around the world.
UPS gets the facts and figures about the world’s largest package delivery company and one of the leading global providers of specialized transportation and logistics services.
It normally takes 3-7 business days to deliver a package to most of the addresses in the world.
TNT has 56,000 employees in 61 countries.
It takes 4-9 business days to deliver the packages to the hands
of our customers.
FedEx offers delivery solutions for customers around the world.
It takes 4-7 business days to deliver the packages to the hands
of our customers.
5. Air, Sea/Air, and Sea
If your order is of large volume with PCBTok, you can also choose
to ship via air, sea/air combined, and sea when necessary.
Please contact your sales representative for shipping solutions.
Note: if you need others, please contact your sales representative for shipping solutions.
You can use the following payment methods:
Telegraphic Transfer(TT): A telegraphic transfer (TT) is an electronic method of transferring funds utilized primarily for overseas wire transactions. It’s very convenient to transfer.
Bank/Wire transfer: To pay by wire transfer using your bank account, you need to visit your nearest bank branch with the wire transfer information. Your payment will be completed 3-5 business days after you have finished the money transfer.
Paypal: Pay easily, fast and secure with PayPal. many other credit and debit cards via PayPal.
Credit Card: You can pay with a credit card: Visa, Visa Electron, MasterCard, Maestro.
“Being optimistic about new companies, especially ones from Asia, is challenging. However, my experience with PCBTok has been different. They genuinely appear to care about making a good job and completing your PCB assembling by the deadline they’ve given you. They are usually polite and concerned in making sure they understand what you want done and when your expectations will be met, whether I stop unexpectedly or on schedule.”Norbert Beier, PCB Assembler from Hannover, Germany.
“More than a year ago, I decided to switch to PCBTok since I thought that another company from my nation was becoming too pricey and slow. Additionally, that local company is not really doing a good job—I’m happy I changed suppliers. I discover along the way that PCBTok provides superior services at fair prices. I now buy PCBTok products exclusively. You should definitely try them out because of their incredible teamwork and effort.”Jorge Hanzlík, Local Buyer from Czech Republic
“It’s wise to leave it to the PCB Experts, like PCBTok. Their PCB prototyping is carried out on-site, and the service is professional. This is significant to me—everything has arrived on schedule. I am a PCB professional adhere to deadlines strictly! Also, they do an excellent job and won’t try to upsell you on anything. Instead, they give you a deadline by which you could require more work. All is well. Good.”Jack Patti, PCB Layout Engineer Product Development from South Carolina.
4 Layer PCB – The Ultimate FAQ Guide
There are a few things you should note about the 4-layer PCB. These layers are responsible for signal routing and power distribution. The components are located on the top and bottom layers, while the power supply layer and signal routing are located on the two inner layers. You should have a good understanding of the various components to make the layout easier. You can also design your own 4-layer PCB using Altium Designer software. here are some tips to help you design your own PCB.
First, you must choose the right material for each layer. Consider prepreg and core thickness, as well as signal layers. Different types of boards have different standard thicknesses. Finally, choose a material with the right mechanical, electrical, and thermal properties. There are several factors to consider when selecting materials for a 4-layer PCB.
Standard 4-Layer PCB
When selecting materials for your design, keep in mind that signal speed varies from layer to layer. For example, if your large device contains BGA components, you will need to route the outer rows and connect them via vias. If you have too many layers in your 4-layer board, you will not have room to route the signal lines. If you are not going to use this method, you can use two layers.
Preparation of materials is the first step in PCB manufacturing. Copper layers and substrates are examples of these materials. Both of these materials act as insulating materials to prevent current and heat from passing through the stack. After the materials are prepared, the plotter printer creates a 4-layer stack of films. This film guides the manufacturing process. The finished product is a 4-layer PCB that can perform a variety of tasks.
4-layer PCBs can be more difficult to manufacture than standard 4-layer boards. 4-layer PCBs are often thinner than traditional four-layer boards, which makes them more difficult and increases manufacturing time. If you are pressed for time and need to complete the PCB quickly, a traditional 4-layer design may be a better choice.
Rogers+FR4 4 Layer PCB
A 4-layer PCB can be designed using a mixed-signal or single-phase design, which does not have a dedicated internal layer for routing. To ensure optimal performance, routing must be planned in conjunction with component placement and escape routing. First, analyze the components you need to place to determine how many layers your project requires. Then, start planning your routing. You will have a better idea of how many layers you need to build.
4-layer printed circuit boards are generally more expensive than double-sided boards. Production and development costs are typically higher than for double-sided designs, and development time is much longer. The more layers you use, the more expensive the product will be, so think about how much you want to spend on a 4-layer board. It is critical to keep these factors in mind when deciding on the type of PCB you want to use.
You may be wondering, “How thick is a 4-layer PCB?” Whether you’re designing a new board or just wondering how thick a 4-layer board should be. Here are some responses. First, keep in mind that the thickness of each layer will vary. Consider the stack-up thickness, which is usually determined by the thickness of the copper foil. Then, choose the material that best combines electrical, thermal, and mechanical properties.
The thickness of a PCB varies by application, weight, and component. It has been scaled down in recent years, but it is still important to consider the design requirements of the project before selecting a PCB manufacturer. For example, a 4-layer printed circuit board may be thicker than a 2-layer board. Some boards may contain high-speed/high-frequency components that require the use of high-frequency materials. If you need a thicker board, consult your PCB manufacturer to ensure your design meets production standards.
Another factor to consider is the prepreg layer. The prepreg layer is a resin-saturated fiber mesh. The core is then laminated to the uncured Fr4 layers. While the thickness of these layers may vary, it is critical to ensure that the core thickness is accurate to achieve high-quality performance. When specifying PCB core thickness, be sure to include all relevant measurements, such as the height and width of the etched board.
4-Layer PCB Stack-up
PCB thickness range from 0.008 inches to 0.240 inches, depending on the application and area of use. The thickness of the PCB is an important factor in the functionality of the PCB, so it is critical to select the correct thickness for your application. Consult the experts at PCBTok to determine the thickness of your PCB. Your PCB manufacturer will likely have a thickness calculator for you.
If you want to know “How to design a 4-layer PCB?” this is the place to go. You’re not alone. The number of 4-layer boards is rapidly increasing, so now is the perfect time to experiment with one of these designs. Listed below are some of the key points to consider when designing your first 4-layer board. These are some tips to ensure that your finished product meets industry standards.
The first step is to gather your materials. For your 4-layer PCB, you will need a substrate and copper layers. These materials act as insulators and prevent current and heat from passing through the stack-up. Then use a plotter printer to create the film for the 4-layer PCB stack. This film will serve as a guide during the production process. If your design is approved, you can proceed to the next step: creating a 4-layer PCB!
Gold Finger 4-Layer PCB
Keep in mind that new wiring twists need to be considered when designing a 4-layer board. For example, the signals on the bottom layer are connected to the power supply layer. When the signal returns current flows through the power supply layer, a bypass capacitor is required. In addition, high-speed signals may require the use of additional bypass capacitors. The bypass capacitor helps to shorten and keep the signal loop area as small as possible.
While most manufacturers use 4-layer stackups, these layers can be stacked in a variety of ways. Some manufacturers refer to them as core plated or core drilled. Both of these methods are valid and effective for 4-layer boards. A good tip is to create your PCB using a CAD tool, such as Altium Designer, which will help you achieve the desired results. The most common PCB design in electronic devices is the 4-layer PCB.
If you are looking for a new way to manufacture electronics, you may be interested in learning about the 4-layer PCB stack-up. This type of board consists of several layers, most often copper. It is then layered and semi-cured with an epoxy-impregnated prepreg material. Afterward, the copper foil is laminated with the prepreg to form a copper-clad laminate. The core is another name for this type of copper-clad laminate.
The grounding layer is located below the surface of each component on the 4-layer board. The signal layer is placed adjacent to the ground layer to ensure that they are tightly coupled. When designing a four-layer board, keep in mind that the ground plane should be as thin as possible to reduce the impedance of the power supply. In addition, 4-layer boards may generate noise.
4-layer stackups are unique and have both advantages and disadvantages. First, they differ in terms of overall thickness and EMI. Then there are the other advantages and disadvantages of each stack. The two most common types of four-layer boards are described below. In the end, the type of board stack will depend on the application and the end product.
4-layer stack-ups are suitable for applications that require a large number of through-holes across a large number of pins in the stack. High-pin-count BGAs are particularly difficult to lay out. The large number of vias required to connect these BGAs to the surface and internal power layers is not sufficient to reduce interlayer capacitance. In addition, it cuts off the GND plane where capacitive coupling cannot be provided.
The 4-layer PCB is the most common in the field of printed circuit boards. However, it is not without its drawbacks. The added cost and complexity are one of them. Another problem is the difficulty of debugging the circuit; in order to locate defective components, you must carefully follow the CAD drawings. Finally, four-layer printed circuit boards are more difficult to reverse engineer. Because X-rays can see through the inner layers, reverse engineering is more difficult.
Lamination is the process of producing a printed circuit board. A 4-layer printed circuit board (PCB) has two internal layers: a thick core layer in the center and two prepreg layers. Generally, the inner layer is used for power and grounding networks, while the top layer is used for signals and mounting components. These layers are then soldered together and have exposed pads. Through holes are typically used for the connection layers.
A common PCB design strategy is to stack 4-layer PCBs. although 4-layer boards are more complex than single-layer boards, they are often preferred due to their versatility and smaller capacity. High assembly density, smaller size, and excellent connection density are just a few of the benefits of 4-layer PCBs. 4-layer designs can also reduce errors and improve product durability.
When selecting materials for 4-layer PCBs, consider the thickness of the signal, core, and prepreg layers. Each layer has a different thickness. Fortunately, there are standard thicknesses for different types of boards. The material used for each layer is determined by its electrical, thermal, and mechanical properties. All of these variables should be considered before finalizing the design. If your requirements are stringent, a 4-layer PCB may be the best choice.