Standard Multilayer PCB Stackup
Multilayer PCB Stackup Planning
In order to properly design the multi-layer printed circuit board, one should carefully consider the design of the layer stack-up. The need for planning the layer stack-up lies, on the one hand, on the technological capabilities of the production, and on another – on the requirements to the electrical properties of the printed circuit board. The latter include the impedance control, signals integrity, noise immunity and electromagnetic compatibility. Another important thing is the optimization of the layers stack-up and interconnections from the point of view of costs. Depending on the choice of the printed circuit board structure the production costs can vary significantly.
One need to remember that the multilayer PCB consists of a combination of cores, prepregs and copper foils. For your choice we have in stock a supply of materials. For their proper selection we recommend to use the table:
Standard copper thickness | 9 μm |
18 μm | |
35 μm | |
50 μm | |
70 μm |
Types and thickness of prepregs | 0,075 mm (1080) |
0,105 mm (2116) | |
0,185 mm (7628) | |
0,216 mm (7628) |
Standard core thickness | 0,1 mm |
0,13 mm | |
0,21 mm | |
0,25 mm | |
0,36 mm | |
0,51 mm | |
0,71 mm | |
1,0 mm | |
1,2 mm | |
1,6 mm | |
2,0 mm | |
2,4 (2,5) mm | |
3,2 mm |
Below we put the most common designs of layers stack-up’s of printed circuit boards. The optimal ones (cheapest) we marked with the icon "Recommended".
4 layer printed circuit board
6 layer printed circuit board
8 layer printed circuit board
10 layer printed circuit board
12 layer printed circuit board
14 layer printed circuit board
16 layer printed circuit board
Prototype PCB
Universal PCB for prototyping
We have created a universal prototype printed circuit board for our clients to give them the possibility to check their ideas at the stage of designing new devices. This PCB contains universal solder pads and the most common types of connectors and commutation elements. The board is also equipped with four built-in power supplies - 1.8V, 3.3V, 5V and an adjustable voltage stabilizer. It is possible to mount a battery compartment that can contain two lithium-ion or alkaline-manganese elements) onto this board.
Our prototype board is also compatible with Raspberry PI 3 and Raspberry PI Zero computers. It also includes the necessary components and connections to mount the Arduino Nano module. It gives the possibility to design and check various types of electronic devices, including those connected to IoT.
Both types of assembling – SMD and THT can be used for this PCB. One- or double-sided assembly is also possible on this board.
Below you can see the specification of our prototype board, including link to the detailed technical information, including a scheme, description of the functionalities and other necessary practical information:
Specification:
- 232 solder pads, including 88 dedicated for power/grounding
- 4 types of stabilized voltage sources (with LED indication) on 1.8V, 3.3V, 5V and with regulated output voltage
- compartment for two batteries
- 3 USB connectors (type A, type B mini and micro)
- connector for programming target systems in the ISP standard
- a Raspberry PI connector
- an Arduino Nano core
- 2 tact buttons
- 1 DIP switch with 8 positions
- 6 LED’s for SMD mounting
- 2 connectors (block terminal and DC jack) + switch for external power supply
- 8 mounting holes (including 2 that can be used for attaching the battery compartment)
You can download User Manual here:
PCB surface finishing
PCB surface finishing
To preserve the solderability of printed circuit boards for a considerable period of time, it is important to protect the copper surface of the soldering pads with a suitable coating or in other words, to provide a so-called surface finishing.
Surface finishing is made on soldering pads and other copper elements opened from solder mask. In modern productions, as a rule the several types of surface finishes with different properties are used.
For the appropriate selection of surface finishes and for their parameters specification there are a number of regulations, of which the most common are the following IPC standards:
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J-STD-003 Solderability Tests for Printed Boards - defines the solderability test methods;
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IPC 2221 Generic Standard on Printed Board Design - defines the basic requirements for the design of printed circuit boards;
-
IPC-7095A Design and Assembly Process Implementation for BGAs - focuses on the BGA components;
We offer a wide range of surface finishes to make an appropriate selection regarding the PCB project requirements.
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HAL or HASL (Hot Air Leveling or Hot Air Solder Leveling) uses the tin-lead (Sn-Pb) alloys and the alignment by the hot air knife. This finishing is currently most commonly used due to its properties. It provides excellent solderability with substantial shelf life. HAL finishing is easy to manufacture and inexpensive. It is compatible with all methods of soldering or assembling - the manual soldering, wave soldering, reflow etc. The negative feature of this type of finishing is the presence of the lead - one of the most toxic metals that are prohibited for use on the territory of the European Union by the RoHS directive (Restriction of Hazardous Substances). Another limitation - it is surface non-uniformity that is not acceptable in case of fine pitch components. Besides it is not compatible with the COB technology (Chip on Board).
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Lead free HASL finishing is similar to the normal HASL, except that it could comprise of different alloys like Sn100, Sn96,5/Ag3,5, SnCuNi, SnAgNi and does not contain lead. The finishing is fully RoHS compliant and meets all the requirements of safety and solderability. However, due to the fact that finishing is applied at the considerably higher temperatures, more rigorous requirements are imposed on PCB base materials. Lead free HASL is compatible with all methods of soldering or assembling both in lead and lead free technologies, but it requires the appropriate temperature profiles during the soldering. As compared to SnPb HAL, it is more expensive due to the higher prices of alloys as well as higher energy consumption.
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Immersion Gold or ENIG (Electroless Nickel/ Immersion Gold ) - the finishing from a Ni/Au family. The thickness of the finishing: Ni 3 – 5.0 µm, Au 0,06 – 0,1 µm. The finishing is made by chemical method. The main function of thin gold layer is to protect the nickel layer from oxidation, and the nickel layer prevents a mutual diffusion of gold and copper. The excellent flatness of the finishing makes it suitable to use in case of fine pitch components. The finishing is fully RoHS compliant. Compatible with all methods of soldering. The main limitation is a higher price. Besides there could be a risk of immersion gold defect due to the oxidation, so-called "black pad" that is critical for BGA assembly.
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Gold Fingers - the finishing from a Ni/Au family. Plating thickness: Ni 5-9 µm, Au 0,2 - 1,0 µm. It is applied by electrochemical deposition (i.e. electroplating). Most often the finishing is used for PCB edge connectors. It has high mechanical strength, resistance to abrasion and adverse environmental effects. Indispensable where it is important to ensure excellent electrical contact with long service life.
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Immersyjna tin - the finishing made chemically. It is compatible with all methods of soldering or assembling. The finishing has an acceptable shelf life period - up to one year. This is achieved by using organic compounds to make the barrier to intermetallic bonds that affect the oxidation of the surface. Such kind of insulating also prevents tin from crystallization. The finishing with the thickness of 1 µm has a good flatness and suitable for fine pitch components.
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OSP (Organic Solderability Preservatives) - a family of organic coatings that applied directly onto the bare copper to protect it from oxidation during storage and soldering. This inexpensive finishing, has a flat surface and is suitable for SMD assembly. It complies with the RoHS directive. As a result it is a cheap alternative to the HASL finishings. Unfortunately, it has a limited shelf life (months) and quickly degrade during the soldering process.
Printed circuit boards materials
Materials for Printed Circuit Boards
The basic structural elements of a printed circuit board include a dielectric substrate (hard or flexible), on the surface of which copper conductors (traces) are located. Additional elements such as soldering points (pads), vias, plated and non-plated holes (mounting), large copper areas (polygons) for heat dissipation, shielding, etc., are used for installing electronic components and their connections.
Dielectric substrates can be made of glass-epoxy laminates or composite materials.
Multilayer printed circuits contain the following elements: basic dielectric material (core), reinforcing material (prepreg, used as dielectric layers during the assembly of a multilayer board), and copper foil (RCC, i.e., copper foil with an adhesive layer).
When choosing a dielectric, parameters such as glass transition temperature (Tg), dielectric constant (Dk), and dielectric loss factor (Df) are most commonly taken into account. The last two parameters are particularly important for printed circuits intended for very high frequencies and microwave ranges.
The glass transition temperature is the temperature at which the material transitions from a solid to a plastic state. Usually, the glass transition temperature represents a temperature range (for example, 135 - 170 °C for FR4). The higher the glass transition temperature of the epoxy resin in a glass-epoxy laminate, the lower the coefficient of linear expansion of the dielectric, which can lead to defects in printed circuits.
Another important characteristic of the material is the dielectric constant (relative permittivity) - the ratio of the capacitance of a test capacitor in which the material is used as a dielectric to the capacitance of the same air capacitor. This characteristic should be taken into account (especially for printed circuits designed for high-frequency ranges) because the high performance of modern electronic circuits places special requirements on parameters such as signal delay time and capacitance of signal lines. The transmission speed of signals in the conductors on the printed circuit board mainly depends on the dielectric constant. The values of the dielectric constant for modern materials used in the production of printed circuits range from 2.2 to 10.2.
The dielectric loss factor in the insulating material is defined as the ratio of the total power loss in this material to the product of voltage and current in the capacitor in which this material is used as a dielectric. The loss factor changes with frequency, resin content in the laminate, temperature, and humidity. The smaller the loss factor, the better the material. In this case, the dielectric loss factor is related to the total signal power loss in the signal lines. It usually increases with frequency. The higher the frequency and, consequently, the dielectric loss factor, the more distorted the signal will be.
For printed circuits on a metal core, the main parameters are thermal conductivity (the material's ability to conduct thermal energy from hotter areas to cooler areas) and breakdown voltage (the voltage at which the specific electrical resistance of the material sharply decreases). It should be remembered that the operating voltage of the system should be lower than the breakdown voltage by 2.5 - 4 times.
Below, you can read descriptions and typical parameters of the basic materials used in our factories, and download technical documentation for each of them.
Types and parameters of materials used for Printed Circuit Board production*
*This list of materials is basic, so if you do not find the required material, we can purchase it upon request or assist in selecting the closest equivalent.
Materials for standard Printed Circuit Boards
Material |
Description |
Glass transition temperature Tg |
Dielectric constant Dk |
Manufacturers and Brands |
---|---|---|---|---|
FR-4 or FR4 |
FR-4 stands for Fire Retardant class 4. This laminate is made from glass fiber with epoxy resin. It is the most commonly used material for printed circuit boards. |
125-140°C |
4,4-4,8 |
GoldenMax GF21 |
FR-4 Mid Tg |
Glass fiber laminate with a slightly increased Tg parameter for the production of double-sided and low-layer count multilayer printed circuit boards. It is an enhanced version of the standard FR4 material. |
150-155°C |
4,6-4,8 |
Nanya NP-155F |
FR-4 High Tg (>170°C), FR-5 |
Glass fiber laminate based on blends of modified epoxy resins. It has increased thermal resistance and greater parameter stability at high temperatures. Recommended for use in multilayer printed circuits and circuits with high conductor density (HDI). |
170-185°C |
4,1-4,8 |
ITEQ IT180 |
FR-4 High CTI (>600V) |
Material based on modified epoxy resins. It is used for printed circuits with high levels of operating voltage in high humidity conditions. |
125-135°C |
4,5-5,0 |
GoldenMax GF11-T6 |
FR-4 Halogen Free |
This type of laminate does not contain halogen, antimony, phosphorus, etc., and does not emit harmful substances during combustion. |
140-150°C |
4,22-4,7 |
KingBoard KB6165G |
CEM-1 |
CEM-1 (Composite Epoxy Material) is a type of laminate made from a combination of glass fiber cloth, epoxy resin, and paper layers. CEM-1 laminates are typically used in products where PCBs are not exposed to harsh environments, for example, in consumer electronics. |
90°C |
4,2 |
KingBoard KB5150 |
CEM-3 | CEM-3 is a more advanced and durable PCB material compared to CEM-1, capable of withstanding slightly higher temperatures and more challenging conditions. | 125°C | 4,4-4,8 | KingBoard KB7150 |
Rigid PI (polyimide) | Polyimide laminate for the production of rigid printed circuit boards. It consists of a polyimide substrate and several layers of prepregs (PP). | >250°C | 4,2-4,4 | Arlon 33N Arlon 85N Shengyi SH260 |
Materials for Flexible and Rigid-Flex Printed Circuit Boards (Flex/Rigid-Flex PCB)
Material |
Description |
Glass transition temperature Tg |
Dielectric constant Dk |
Manufacturers and Brands |
---|---|---|---|---|
Pl (polyimide) |
Thin films made from polymerized polyimide. This material is used for the production of flexible and rigid-flex printed circuit boards. |
280-350°C |
3,2-3,6 |
Panasonic RF770 |
PET (polyethylene terephthalate) |
Films made from a thermoplastic polymer belonging to the class of polyethers. This material has high mechanical strength and is resistant to repeated deformations. |
100°C |
3,3 |
Jiu Jiang LPET |
Materials for Very High Frequencies and Microwave Ranges
Material |
Description |
Dielectric loss factor Df |
Dielectric constant Dk |
Manufacturers and Brands |
---|---|---|---|---|
PTFE |
Polytetrafluoroethylene (PTFE) polymer reinforced with glass fiber. This material is known for its high reliability, electrical strength, resistance to moisture, and ability to operate at high temperatures. |
0,0004-0,0078 |
2,17-10,2 |
Arlon DiClad series |
PTFE with ceramic filler |
Polycarbonate-based polymer (carbon resins) with a fine ceramic filler, reinforced with glass fiber. |
0,0011-0,0040 |
2,94-10,2 |
Arlon 25N/25FR |
Ceramic composites |
Composite materials based on ceramics with organic binders are characterized by low losses. |
0,0016-0,0023 |
3,0-12,85 |
Rogers TMM series |
FR4 High Frequency |
This refers to a group of modified glass fiber laminates designed to operate in high-frequency ranges. |
0,003-0,010 |
3,5-3,6 |
Shengyi S7136H |
Materials for Printed Circuits on metal substrates
Material |
Description |
Thermal conductivity |
Breakdown Voltage |
Manufacturers and Brands |
---|---|---|---|---|
Aluminium CCL |
This is a type of copper laminate known as Aluminium Clad Copper Laminate, which consists of an aluminum substrate and a thin dielectric layer with a copper layer on top. This construction allows for better heat dissipation, which is particularly important in high-power applications. |
0,6-3,0 |
3-5 |
Boyu AL-01-P |
Other materials for Printed Circuit Boards
Materiał |
Opis |
Glass transition temperature Tg |
Dielectric constant Dk |
Manufacturers and Brands |
---|---|---|---|---|
PP (prepregs) |
Prepreg is a composite material consisting of reinforcing fibers such as glass or other types, which have been impregnated with partially cured resin. The resin is typically epoxy, but it can also be polyimide or another type of polymer. |
130-180°C |
2,8-4,6 |
|
RCC |
The acronym stands for Resin Coated Copper, which refers to a copper foil with a layer of resin. It is used as the base material for the layers of multilayer printed circuits, including circuits in HDI technology. |
150-170°C |
3,5-4,4 |
|
Copper foil |
This is a material in the form of thin copper foils, typically available in rolls. Copper foils are used to create stacks of layers in printed circuits by pressing them together with prepreg layers and other laminates. |
- |
- |
Detailed parameters and datasheets of materials for standard Printed Circuit Boards.
FR-4
The abbreviation FR-4 stands for Flame Retardant 4. The term "FR" originates from the rating system developed by NEMA (National Electrical Manufacturers Association, USA). This specific rating indicates that the material meets the UL94V-0 standards, meaning it is flame retardant. It is one of the most commonly used materials for printed circuit boards. The material finds a wide range of applications, from consumer electronics to medical, military, and aerospace devices, although it is not recommended for high-frequency applications.
Furthermore, FR-4 is known for its good mechanical properties, such as high strength, and it is easy to work with, allowing processes like milling or cutting. It also possesses good chemical resistance, low water absorption, and is heat-resistant. However, one of its main limitations is its poor thermal conductivity, which can be a challenge in high-power applications.
In general, FR-4 is a versatile and cost-effective material for printed circuit boards. However, its limitations should be taken into consideration when choosing it for a specific application. Engineers may consider using other materials like polyimide or ceramic substrates for high-power or high-frequency applications.
Depending on its properties and application, FR-4 is divided into the following subclasses:
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Standard, with a glass transition temperature (Tg) of ~ 130°C, with or without ultraviolet (UV) blocking. This is the most common and widely used type, also the least expensive within the FR-4 category.
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Medium Tg, with a glass transition temperature (Tg) of ~ 150°C. Suitable for lead-free soldering technology and for most low-layer count multilayer printed circuits.
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High Tg, with a glass transition temperature (Tg) of ~ 170°C-185°C. Suitable for lead-free soldering technology and recommended for use in multilayer printed circuits with a higher layer count (above 6 layers).
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High Comparative Tracking Index (CTI) ≥ 400, ≥ 600.
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Halogen-free, suitable for lead-free soldering technology.
High Tg FR-4 laminates are manufactured using dianic epoxy resins and a special type of woven glass fiber. They are essential for applications where printed circuits will be operated in challenging thermal conditions, such as the automotive industry, industrial electronics, or aerospace industry.
High CTI (Comparative Tracking Index) laminates are used in applications where printed circuits will be operated in harsh environmental conditions, such as high humidity, large temperature variations, or demanding industrial conditions. These laminates have higher breakdown resistance, providing better protection in critical applications. The CTI parameter represents the relative resistance of the material to the formation of a conductive path on the surface of the printed circuit when the surface is exposed to electric fields in the presence of contaminants containing water. It indicates the highest working voltage for a given laminate. The higher the CTI value, the higher the breakdown resistance.
FR-4 laminate achieves its flame resistance through the presence of bromine, which is a halogen commonly used in industry due to its flame-retarding properties. However, bromine is a highly toxic chemical component that is released into the environment during material combustion. To limit the use of such substances, halogen-free laminates are used. These materials are produced based on modified epoxy resins that do not contain halogens, antimony, and phosphorus.
FR-4 laminates used in our production and their typical parameters
(you can download datasheets for these materials via the link):
Manufacturer/Brand |
Glass transient temperature Tg |
Dielectric constant Dk |
Datasheet |
---|---|---|---|
Laminates with standard glass transition temperature | |||
GoldenMax GF21 | >125°C | 4,4-4,8 | Download |
KingBoard KB6160 | 135°C | 4,58 | Download |
Nouya NY1135 | 135°C | 4,6 | Download |
Nouya NY1140 | 140°C | 4,6 | Download |
Nouya NY2140 | >135°C | 4,8 | Download |
Shengyi S1141 | 140°C | 4,4 | Download |
Laminates with medium glass transition temperature | |||
Nanya NP-155F | 155°C | 4,6-4,8 | Download |
Nouya NY2150 | >150°C | 4,7 | Download |
Shengyi S1000 | 155°C | 4,7 | Download |
Shengyi S1000H | 160°C | 4,9 | Download |
Shengyi S1141 150 | 150°C | 4,6 | Download |
Laminates with high glass transition temperature | |||
ITEQ IT-180 | 175°C | 4,4 | Download |
KingBoard KB6167F | >170°C | 4,8 | Download |
Nanya NP-175FM | 170°C | 4,1-4,3 | Download |
Nouya NY1170 | 170°C | 4,6 | Download |
Nouya NY2170 | 170°C | 4,6 | Download |
Shengyi S1000-2 | 170°C | 4,8 | Download |
Shengyi S1000-2M | 185°C | 4,6 | Download |
Laminates with high CTI | |||
GoldenMax GF11-T6 | >125°C | 4,5-4,8 | Download |
Nouya NY1600 | 135°C | 4,6 | Download |
Shengyi S1600 | 135°C | 4,7 | Download |
Shengyi S1600L | 135°C | 5,0 | Download |
Halogen-free laminates | |||
KingBoard KB6165G | 150°C | 4,7 | Download |
Shengyi S1155 | 140°C | 4,22 | Download |
Polyimide laminates |
|||
Arlon 33N | >250°C | 4,25 | Download |
Arlon 85N | >250°C | 4,39 | Download |
Shengyi SH260 | >250°C | 4,22 | Download |
FR-1/FR-2
FR-1 and FR-2 are material classes according to the NEMA classification. These composite materials are produced from phenolic-paper base and are used exclusively for the production of single-sided printed circuit boards. FR-1 and FR-2 have similar parameters, with FR-1 differing only in a higher glass transition temperature. Due to the similarity in parameters and application range, most material manufacturers produce only one of these materials, most commonly FR-1. These materials are well-suited for mechanical processing (milling, cutting). They have a UL94-V0 flammability rating.
They are divided into the following subclasses:
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Standard
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Halogen-free, without phosphorus and antimony, non-toxic
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With normalized CTI index ≥ 400, ≥ 600
-
Waterproof;
CEM-1
CEM-1 is a material class according to the NEMA classification. These composite materials are produced from a phenolic-paper base, with two layers of glass fabric on the outside. They are typically milky-white or milky-yellow in color. They are not compatible with the through-hole metallization process, which is why they are used only for the production of single-sided printed circuit boards. Their dielectric properties are similar to FR-4, but their mechanical properties are slightly inferior. CEM-1 is a good alternative to FR-4 for the production of single-sided printed circuit boards when cost is a determining factor. These materials are well-suited for mechanical processing (milling, cutting). They have a UL94-V0 flammability rating.
They are divided into the following subclasses:
-
Standard
-
High-temperature resistant, suitable for lead-free tinning and soldering
-
Halogen-free, without phosphorus and antimony
-
With normalized CTI index ≥ 600
-
Waterproof, with increased dimensional stability
CEM-3
CEM-3 is a family of materials according to the NEMA classification. It is a composite material based on epoxy fiberglass typically in milky-white or transparent color. It is often used for the production of double-sided printed circuit boards. In terms of properties, it is very similar to FR-4 and only differs in slightly lower mechanical strength. It is a cheaper alternative to FR-4 for the absolute majority of applications. These materials are well-suited for mechanical processing (milling, cutting). They have a UL94-V0 flammability rating.
Depending on their properties and application, CEM-3 is divided into the following subclasses:
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Standard, with or without ultraviolet (UV) blocking
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High-temperature resistant, suitable for lead-free tinning and soldering
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Halogen-free, without phosphorus and antimony
-
With normalized CTI index ≥ 600
Here are the composite laminates CEM-1 and CEM-3 used in our production, along with their typical parameters.
(You can download datasheets for these materials via the link):
Manufacturer/Brand |
Glass transition temperature Tg |
Dielectric constant Dk |
Datasheet |
---|---|---|---|
CEM-1 laminates | |||
KingBoard KB5150H | 140°C | 4,2 | Download |
CEM-3 laminates | |||
coming soon... | Download |
Detailed specifications and datasheets for materials used in high-frequency printed circuits
For the production of printed circuits operating in high-frequency and microwave ranges, specialized laminates with low dielectric loss (Df) and a dielectric constant (Dk) in the range of 2-3 are used. Materials meeting these requirements often include PTFE composites, thermosetting materials with ceramic fillers, and laminates on ceramic substrates. For less demanding applications, modified FR-4 laminates designed for high-frequency ranges (High Frequency FR-4) are used.
PTFE (Teflon)
Materials based on fluorocarbon compounds reinforced with glass fiber. Printed circuits made on such materials have increased reliability, electrical strength, moisture resistance, and can operate at high temperatures. These materials are widely used in the production of linear power amplifiers, antennas for communication systems, including satellite systems, as well as other radio communication elements. Additionally, these materials have found application in fast digital applications where signal integrity and accuracy are a priority.
RO3000
A series of materials developed for wide application in the early 1990s. These materials have excellent electrical properties in the very high-frequency range. The coefficient of thermal expansion (CTE) along the X and Y axes for these materials is similar in value to the CTE of copper and FR4, enabling the production of reliable RO3000/FR4 hybrid assemblies. Low dielectric losses (Df ~ 0.0013 at 10 GHz) are a significant advantage when using laminates from this series in microwave devices.
RO4000
This is a series of materials for use at high frequencies. They were developed to provide quality parameters for very high-frequency ranges, comparable to materials containing polytetrafluoroethylene (PTFE), while simplifying the production technology of boards to be in line with traditional processing of reinforced laminates (FR4). The RO4000 materials consist of high-temperature glass fiber (Tg ~ 280 °C) with a thermosetting polymer filler with the addition of ceramics.
Materials for high-frequency applications used in our production and their typical parameters
(you can download datasheets for these materials via the link):
Manufacturer/Brand |
Dielectric loss factor Df |
Dielectric constant Dk |
Datasheet |
---|---|---|---|
PTFE laminates | |||
Arlon AD10 | 0,0078 | 10,2 | Download |
Arlon AD255A | 0,0014 | 2,55 | Download |
Arlon AD350A | 0,0030 | 3,50 | Download |
Arlon AD1000 | 0,0023 | 10,2 | Download |
Arlon DiClad 527 | 0,0010 | 2,5 | Download |
Arlon DiClad 870 | 0,0009 | 2,33 | Download |
Arlon DiClad 880 | 0,0008 | 2,18 | Download |
Rogers RT\duroid 5870 | 0,0005 | 2,33 | Download |
Rogers RT\duroid 5880 | 0,0004 | 2,20 | Download |
Taconic TLY Series | 0,0009 | 2,17-2,33 | Download |
Laminates with ceramic filler | |||
Arlon 25N/25FR | 0,0025-0,0035 | 3,38-3,58 | Download |
Rogers RO3003 | 0,0013 | 3,0 | Download |
Rogers RO3006 | 0,0020 | 6,15 | Download |
Rogers RO3010 | 0,0023 | 10,2 | Download |
Rogers RO4003C | 0,0027 | 3,38 | Download |
Rogers RO4350B | 0,0037 | 3,48 | Download |
Rogers RO4450B | 0,0040 | 3,30-3,54 | Download |
Taconic RF-10 | 0,0025 | 10,2 | Download |
Taconic RF-35 | 0,0018 | 3,5 | Download |
Taconic RF-60A | 0,0028 | 6,15 | Download |
Taconic TSM-DS3M | 0,0011 | 2,94 | Download |
Laminates with ceramic substrates | |||
Rogers TMM3 | 0,0020 | 3,27 | Download |
Rogers TMM4 | 0,0020 | 4,5 | Download |
Rogers TMM6 | 0,0023 | 6,0 | Download |
Rogers TMM10 | 0,0022 | 9,2 | Download |
Rogers TMM10i | 0,0020 | 9,8 | Download |
Rogers TMM13i | 0,0019 | 12,85 | Download |
Taconic HF-300 | 0,0016 | 3,0 | Download |
FR-4 laminates for High Frequency ranges |
|||
Shengyi S7136H | 0,0030 | 3,61 | Download |
TUC TU-872 SLK | 0,0100 | 3,5 | Download |
Detailed parameters and datasheets of materials for flexible and rigid-flex printed circuits
Flexible and rigid-flex printed circuits are becoming increasingly popular. The use of such printed boards allows for increased reliability of connections, integration with complex enclosures, and reduction in the dimensions and weight of devices.
For the rigid parts of rigid-flex printed circuits, the same materials are used as for conventional multilayer printed circuits. However, for flexible parts or standalone flexible printed circuits, special materials such as polyimide or PET are used.
Polyimide
It is a flexible polymer film that serves as the substrate for flexible printed circuits. There are several formulations of polyimide available under commercial brands like Kapton, Rogers, Dupont.
Advantages:
-
Excellent flexibility at all temperatures
-
Good electrical properties, excellent chemical resistance (except for hot concentrated alkali)
-
Very good tear strength
-
Operating temperature from -200°C to +300°C
Some types of polyimides have additional advantages (e.g., coefficient of expansion matching those of copper)
Disadvantages:
-
High water absorption (up to 3% by weight)
-
Relatively high price
Despite its high glass transition temperature, the high-temperature properties of polyimide-based boards are limited by adhesives for bonding layers.
The thickness of polyimide film can vary widely, but in practice, most offered flexible materials have a thickness in the narrow range of 12 to 125 μm. When designing flexible printed circuits, the following principle can be useful: the stiffness of flexible materials is proportional to the cube of their thickness. This means that if the thickness of the material is doubled, it becomes eight times stiffer, and at the same load, it will deform eight times less.
PET
Polyethylene terephthalate (PET) can also be used as a flexible material. However, due to its low melting temperature, the possibilities for soldering on this material are significantly limited. PET is a good dielectric, has high chemical resistance to acids and bases, and increased resistance to water vapor. The mechanical properties of copper-coated PET films are better in terms of tear strength, dielectric constant, and insulation resistance. Operating temperature range from -60°C to +105°C.
These films also have the following advantages:
-
It is a low-temperature thermoplastic (easy to shape)
-
It has very good flexibility
-
Good electrical properties
Disadvantages:
-
Limited solderability (has a low melting temperature)
-
Cannot be used at very low temperatures (becomes brittle)
-
Insufficient dimensional stability.
Materials for flexible and rigid-flex PCBs used in our production and their typical parameters
(you can download datasheets of the materials via the link):
Manufacturer/Brand |
Glass transition temperature Tg |
Dielectric constant Dk |
Datasheet |
---|---|---|---|
Polyimide | |||
Panasonic RF770, RF775 | 343°C | 3,2 | Download |
Shengyi SF302 | >280°C | 3,5 | Download |
Shengyi SF305 | >280°C | 3,6 | Download |
ThinFlex A-3005RD | 350°C | 3,3 | Download |
ThinFlex A-3010RD | 350°C | 3,3 | Download |
ThinFlex A-4005RD | 350°C | 3,3 | Download |
ThinFlex A-4010RD | 350°C | 3,3 | Download |
ThinFlex W-2005RD-C | 350°C | 3,3 | Download |
ThinFlex W-2010RD-C | 350°C | 3,3 | Download |
PET | |||
Jiu Jiang LPET | 100°C | 3,3 | Download |
Detailed parameters and datasheets of materials for printed circuits on metal substrates
To enhance heat dissipation in a printed circuit, a laminate with a metal substrate, such as aluminum coated with a dielectric, can be used. These materials are employed to improve the heat dissipation from assembled components, particularly in electronic equipment with high operating currents at elevated temperatures. We can offer the production of single- and multi-layer printed circuits on aluminum substrates with various thermal conductivity and breakdown voltage values.
Materials on aluminum substrates used in our production and their typical parameters
(datasheets for these materials can be downloaded from the link):
Producent/Nazwa |
Thermal conductivity λ (W/m*K) |
Breakdown Voltage |
Datasheet |
---|---|---|---|
Boyu AL-01-P | 0,6 – 0,8 | 3kV | Download |
Boyu AL-01-A | 1,0 – 1,8 | 3kV | Download |
Boyu AL-01-B | 2,0 – 2,8 | 3kV | Download |
Boyu AL-01-L | 3,0 | 3kV | Download |
GoldenMax GL12 | 0,8 – 1,0 | 4kV | Download |
Production capabilities
Production capabilities
An engineer must be proficient in the capabilities of the technological process based on which the board will be manufactured. Compliance with technological standards at the design phase of a printed circuit board ensures its subsequent high-quality and reliable production, enables high volumes to be produced by minimizing defects, and also ensures the reliable functioning of the devices where the PCB is used. The above allows to reduce cost on both the product introduction phase and its operational phase.
For your convenience, we put the most important technological parameters into the table:
Common parameters (single-, double- and multilayer printed circuit boards) | Value |
---|---|
Board thickness, mm |
0,4-3,2 |
Copper thickness, μm |
9, 18, 35, 70, 1051 |
Maximum PCB dimensions, mm |
550,0 х 1150,0 |
Material |
FR1, FR2, FR4, CEM1, CEM3, halogen free; with index of CTI ≥ 400, ≥600; for RF and microwave freq. range (Rogers, Arlon); high Tg materials – up to 175 0C; metal core and other. 2 |
PCB outline processing |
routing, scoring (V-cut), punching |
Surface finishing |
HAL RoHS (Lead free), HAL SnPb, Immersion gold (ENIG), Immersion Tin, Gold Flash, Gold Fingers, carbone, OSP |
Legend colour |
white, black, yellow, green 3 |
Solder mask colour |
green, white, black (glossy and matte), red, blue 3 |
Parameters | Typical | Advanced |
---|---|---|
Multilayer PCB |
||
Number of layers |
4-14 |
4-28 |
Minimum conductor width4, mm |
0,1 |
0,076 |
Minimum conductors space4, mm |
0,1 |
0,076 |
Minimum space between conductor and board’s outline (outer layers / inner layers), mm |
0,5/0,5 |
0,3/0,5 |
Minimum hole size (mechanical drilling)6, mm |
0,2 |
0,2 |
Aspect ratio |
1:8 |
1:12 |
Minimum annular ring5, mm |
0,15 |
0,127 |
Blind vias |
yes |
yes |
Buried vias |
yes |
yes |
Minimum solder mask swell, mm |
0,05 |
0,05 |
Minimum solder mask bridge, mm |
0,1 |
0,1 |
Legend width (silkscreen), mm |
- |
0,1 |
Minimum legend symbol height (silkscreen), mm |
1,0 |
0,7 |
Multilayer HDI PCB |
||
Number of layers |
4-16 |
4-28 |
Build-up |
3-N-3 |
4-N-4 |
Minimum conductor width4, mm |
0,1 |
0,076 |
Minimum conductors space4 (outer layers / inner layers), mm |
0,1/0,076 |
0,076/0,064 |
Minimum space between conductor and board’s outline (outer layers / inner layers), mm |
0,5/0,5 |
0,3/0,5 |
Minimum hole size (laser drilling), mm |
0,1 |
0,075 |
Minimum annular ring5 (outer layers / inner layers), mm |
0,15/0,1 |
0,127/0,1 |
Via-in-pad technology |
yes |
yes |
Stacked and staggered micro vias |
yes |
yes |
Copper plugged vias |
yes |
yes |
Resin plugged vias |
yes |
yes |
Minimum solder mask swell, mm |
0,05 |
0,025 |
Minimum solder mask bridge, mm |
0,1 |
0,1 |
Double sided PCB |
||
Minimum conductor width4, mm |
0,15 |
0,1 |
Minimum conductors space4, mm |
0,15 |
0,1 |
Minimum space between conductor and board’s outline, mm |
0,5 |
0,3 |
Minimum hole size, mm |
0,3 |
0,2 |
Aspect ratio |
1:8 |
1:12 |
Minimum annular ring5, mm |
0,2 |
0,15 |
Minimum solder mask swell, mm |
0,1 |
0,05 |
Minimum solder mask bridge, mm |
0,15 |
0,1 |
Legend width (silkscreen), mm |
- |
0,1 |
Minimum legend symbol height (silkscreen), mm |
1,0 |
0,7 |
Single sided PCB |
||
Minimum conductor width4, mm |
0,2 |
0,15 |
Minimum conductors space4, mm |
0,2 |
0,15 |
Minimum space between conductor and board’s outline, mm |
0,5 |
0,3 |
Minimum hole size, mm |
0,5 |
0,4 |
Minimum annular ring5, mm |
0,3 |
0,2 |
Minimum solder mask swell, mm |
0,1 |
0,05 |
Minimum solder mask bridge, mm |
0,2 |
0,1 |
Legend width (silkscreen), mm |
- |
0,1 |
Minimum legend symbol height (silkscreen), mm |
1,5 |
1,0 |
Flex PCB |
||
Number of layers |
1-6 |
|
Material |
Polyimide, PET |
|
Minimum conductor width4, mm |
0,15 |
0,1 |
Minimum conductors space4, mm |
0,15 |
0,1 |
Minimum space between conductor and board’s outline, mm |
0,5 |
0,25 |
Minimum hole size, mm |
0,3 |
0,2 |
Coverlay swell (coverlay to soldering pad gap), mm |
0,2 |
0,1 |
Aluminum core PCB |
||
Number of layers |
1-2 |
1-4 |
Board thickness, mm |
0,5-3,2 |
|
Copper thickness, μm |
35 |
|
Dielectric thickness, μm |
50, 75, 100, 150 |
|
Thermal conductivity, W/mK |
0,7-4 |
|
Breakdown voltage, kV |
2-12 |
|
Maksimum PCB dimensions, mm |
550,0 х 950,0 |
|
Material |
AL 5052 |
|
Minimum conductor width4, mm |
0,2 |
0,15 |
Minimum conductors space4, mm |
0,2 |
0,15 |
Minimum space between conductor and board’s outline, mm |
0,5 |
0,25 |
Minimal hole size, mm |
0,9 |
0,6 |
Minimum solder mask swell, mm |
0,15 |
0,05 |
1 It is possible to make thicker copper on demand.
2 Other materials on demand.
3 Other colours on demand.
4 For copper thickness 9 μm and 18 μm.
5 (Pad size – hole size)/2
6 It is possble to use laser drilling on demand.
Minimum clearances for different cooper thicknesses
Finished copper thickness, μm | 35 | 70 | 105 | 140 | 210 |
Minimum Trace, mm | 0,1 | 0,20 | 0,23 | 0,30 | 0,60 |
Minimum clearance, mm | 0,1 | 0,20 | 0,24 | 0,35 | 0,70 |
Finished copper thickness, μm | 35 | 70 | 105 | 140 | 210 |
Minimum Trace, mm | 0,1 | 0,20 | 0,27 | 0,34 | 0,60 |
Minimum clearance, mm | 0,1 | 0,20 | 0,30 | 0,45 | 0,85 |