Before investing in your nest Epoxy resin PCB, read this guide.
It answers all questions you have been asking about epoxy resin.
So, keep reading to learn more.
What Is An Epoxy Resin PCB?
This is a printed circuit board that you will hold together using an epoxy resin, which is also called polyepoxide.
What Safety Precautions Should You Use When Using Epoxy When Making An Epoxy Resin PCB?
There are several safety measures that you should undertake when you are fabricating an epoxy resin PCB.
This is because you are using epoxy resin as one of the fabrication materials when making the printed circuit board.
The first step you need to do is put on gloves that will protect your hands from being exposed to the epoxy resin.
One of the recommended gloves that you need to put on your hands is Nitrile gloves.
Besides, you can use other simple substances such as baby wipes to eliminate the epoxy resin if it contacts your skin during the fabrication process.
For the epoxy resin that remains on your skin, you can remove it using water and soap mixture.
Also, you need to wear a plastic apron when fabricating an epoxy resin PCB.
This is because the plastic allows the easy removal of the epoxy resin substance if it happens to spill on the apron.
Also, put on safety goggles as they will protect your eyes.
If the epoxy resin contacts your eyes, you should use clean water to flush your eyes for almost 15 minutes.
In addition, do not rub your eyes during this process, and afterward, you can seek medical attention at the earliest convenience.
The last step entails fabricating the epoxy resin PCB in a location that has ample ventilation.
This is important as it ensures clean circulation of air within the work area.
For instance, you can ensure that you open the windows or turn on fans within your work area to assist with the air circulation.
Also, you can put on a respirator in instances where the circulation of air is insufficient due to one reason or another.
Can You Use Various Types Of Epoxy Resin When Making An Epoxy Resin PCB?
The epoxy resin that you can use when fabricating an epoxy resin PCB can fall into two distinct categories.
These include the following:
- Non-glycidyl
In this category, you can find the following subcategories:
- Cyclo-aliphatic
- Aliphatic
- Glycidyl
This type of epoxy resin will fall under the umbrella of the following:
- Glycidyl-ether, which happen to the most popular epoxy resins that you will use when fabricating epoxy resin PCB
- Glycidyl-amine
- Glycidyl-ester
Here are some of the types of epoxy resins you can use when manufacturing an epoxy resin PCB:
- Bisphenol Epoxy Resin
One of the most popularly epoxy resins for commercial production of epoxy resin PCB is DGEBA [Bisphenol-A diglycidyl ether].
To produce it, you will expose epichlorohydrin to bisphenol-A within the presence of a standard catalyst substance to produce a reaction.
Besides, the molecular density of this epoxy resin is the lowest.
- Novolac Epoxy Resin
To produce this epoxy resin, you will react methanol and phenol.
Besides, these epoxy resins lack VOCs or volatile organic compounds, and solvents.
Since they lack volatile organic compounds, they are suitable for use when making epoxy resin printed circuit boards.
For this reason, you also need not use respirators.
Besides, the adhesive strength of novalac epoxy resin is strong, thus are suitable for different coverage levels.
Besides, the epoxy resin PCBs you fabricate using this epoxy has a high durability and protection level.
This makes it suitable for various uses.
- Glycidylamine Epoxy Resin
This epoxy resin is highly functional and forms due to a reaction between epichlorohydrin and aromatic amines.
Some industrial versions of this epoxy resin entail N,N,N′,N′-tetraglycidyl-bis-(4-aminophenyl)-methane and triglycidyl-p-aminophenol.
At room temperature, they have a medium to low level of viscosity, thus are simple to work with than other varieties.
- Diluents Epoxy Resin
To form this epoxy reaction, you will use substances such as polyols or aliphatic alcohol glycidylation.
After this reaction, the substance you create can either be difunctional, monofunctional, or highly functional.
- Aliphatic Epoxy Resin
A reaction involving epichlorohydrin or epoxidation results in the formation of aliphatic epoxy resin.
Also, due to lack of chlorine and high content of oxirane, they possess the following qualities:
- High Tg
- Low level of viscosity
- Low dielectric constant
- Suitable weather resistance
- Halogenated Epoxy Resin
This version of epoxy resin is usually admixed for unique features when fabricating an epoxy resin PCB.
To make them, you will mix fluorinated and brominated substances.
Also, the most common substance is brominated bisphenol A since it is flame resistant and useful for electrical usages.
However, making these epoxy resins in large amounts is limited as they are expensive and have a low Tg.
What Substrate Materials Can You Use When Making An Epoxy Resin PCB?
The substrate material that you will use to fabricate an epoxy resin PCB falls into four distinct categories.
These include the following:
Rigid Or Hard Substrate Materials
If the main purpose is to ensure the epoxy resin PCB maintains its shape with time, you need to use ceramic-based or rigid material.
Since these materials have a solid trait, the epoxy resin PCB will not deform, thus maintaining its shape throughout its lifecycle.
An example where you will use a rigid material to make an epoxy resin PCB is when constructing computer motherboards.
Examples of rigid materials you can use when making an epoxy resin PCB include beryllium oxide or aluminum nitride.
Some of the advantages of using these hard substrate materials include the following:
- They will continue being functional even in temperatures exceeding 350 °C.
- Also, they possess high levels of dielectric constants.
- Since they absorb the least amount of moisture, they facilitate hermetic packaging.
- Besides, they will not experience any issues with outgassing.
- They allow packaging in small configurations and work well with other PCB parts.
Some of the reasons why you need to use hard substrates to make epoxy resin PCBs include:
- Situations where you require clear signal paths.
- When you need to lower the price during a large number of production runs.
- In areas where the application needs a sturdy printed circuit board.
- When you need to conduct quick maintenance and repair practices.
Flexible Or Soft Substrate Materials
When you use flexible substrate materials, you are open to using them in various applications as they can fold or bend into several shapes.
For this reason, many modern electronics for consumers use these substrate materials in epoxy resin PCBs.
Also, you will use flexible substrates in epoxy resin PCBs when the application requires it to frequently flex during operation.
The flexible substrate allows this to occur without affecting the flow of current.
Examples of the industries that use this substrate include smartphones, wearables, etc.
The material you will use when fabricating flexible epoxy resin PCBs is called Kapton.
Besides, this material is suitable for heat resistance, is consistent dimensionally, and has suitable dielectric constant values.
The most popular flexible epoxy resin PCB material substrate is polytetrafluoroethylene and polyimide.
Some advantages of using flexible epoxy resin PCB materials include:
- They occupy less space thus enhancing the portability of the application
- Their weight is minimal thus suitable for small applications
- They are suitable for making epoxy resin PCBs that will experience tuff environments
- Also, they can suitably accommodate high-signal trace and density usages due to their small size
- The flexible epoxy resin PCBs will offer suitable stability since they form a coat close to the fillers.
Some situations that require the use of flexible epoxy resin PCB materials entail:
- When the epoxy resin PCB design is for extreme conditions
- In applications that need the epoxy resin PCB to bend or flex
- When you require lightweight and small epoxy resin PCBs
Rigid-flex Substrate Material
These epoxy resin PCBs use both rigid and flexible materials.
Besides, they contain several layers, formed by polyimide materials.
Some advantages of the rigid-flex epoxy resin PCBs include:
- Ease of machining
- They possess low levels of dielectric loss
- Also, they are lightweight and occupy less space
- They build requires precision
Areas that require you to use rigid-flex epoxy resin PCBs include:
- When making power amplifiers and receivers
- In situations that need lightweight epoxy resin PCBs
- When containing tags relative to frequency identification
- Boards for military and medical application
- Building sensors and radar systems for automotive
RF-4 Substrate Material
These are fiberglass-epoxy material that is relatively affordable, suitably fire-resistant, and good at electrical insulation.
FR means fire retardant, meaning it will comply with UL94VO certification.
Their flame-resistant trait is because they comprise bromine halogens.
The advantages of FR-4 epoxy resin PCB material include:
- They are affordable and adaptable
- Also, their construction comprise prepreg sheets that have epoxy resin and a fiberglass matting
- They are easy to bore and metalize regarding standards of electronic industries
Instances that require the use of FR-4 epoxy resin PCB include:
- During prototyping
- When fabricating complex designs requiring several layers
- In scenarios where you need to lower production costs
- Applications that need low-speed circuits
Is An Epoxy Resin PCB Strong?
Epoxy resin PCBs are strong but this depends on the epoxy strength of the variety you are using.
Some of the main strength traits entail:
- Compressive strength
- Peel strength
- Shear strength
- Flexural strength
The epoxy adhesive you will use on an epoxy resin PCB presents high levels of strength.
Besides, some of the heat-curable epoxy adhesives come with a strength value ranging between 35 N/mm2 to 41 N/mm2.
Should An Epoxy Resin PCB Comply With A Set Of International Quality Standards?
Yes, an epoxy resin PCB has to comply with these quality standards as it ensures they are safe for use and meet the set requirements.
Some of the quality standards that an epoxy resin PCB should comply with include the following:
- UL certification
- Restriction of Hazardous Substances [RoHS]
- SGS certification
- ISO 9001 and 14000 certification
Which Surface Finishes Can You Use When Making An Epoxy Resin PCB?
The purpose of the PCB surface finish you will use on an epoxy resin PCB will protect components on the PCB from oxidation or shorts.
Besides, the surface finish forms a suitable connection that forms between the epoxy resin PCB parts and the PCB itself.
Some of the surface finishes you can use on an epoxy resin PCB include the following:
- Organic Solderability Preservatives [OSP]
- Immersion silver
- Electroless Nickell Immersion Gold [ENIG]
- Gold or Nickel Electrolytic
- Lead-Free Hot Air Solder Leveling [HASL]
- Immersion or white tin
- Electroless Nickel Electroless Palladium Immersion Gold [ENEPIG]
What Is The Manufacturing Process Of An Epoxy Resin PCB?
The steps involved in the manufacture of an epoxy resin PCB entail the following:
- Design
Here, designers create a blueprint of the epoxy resin PCB.
- Printing
In this phase, you will print the epoxy resin PCB through the use of a plotter printer.
- Substrate
When making this PCB, you will use a substrate layer that composes of insulating layers.
In this case, the substrate layer you will use is epoxy resin, which will connect all elements.
Afterward, you will cure the materials in an oven before etching the design of the epoxy resin PCB.
- Layers
In this phase, you will create laminates within the inner layers using blueprints.
For instance, you will cover the laminate with a photosensitive film which hardens when you expose it to UV light.
- Bonding
Here, you will expose the panel to UV light which hardens the photoresist layers, thereby revealing underlying copper connections.
- Refining
This phase involves using a chemical solution made of alkaline that eliminates surplus copper without damaging the photoresist layer.
- Inspection
Automatic machines inspect the layers to ensure all layers align with one another.
- Lamination
This entails pressing all layers and laminating them using an epoxy resin known as prepreg.
Also, you will punch pins through the layers to ensure they align.
Besides, you will apply heat and pressure to melt the epoxy resin, thereby causing the layers to fuse.
Finally, you will drill holes on the layers which expose substrate layers and inner panels.
- Plating
Here, you will thoroughly clean and bathe the panels in chemical solutions.
The solution will deposit a thin copper layer on the surface which seals the plate and enters the holes.
- Imaging
Here, you will, a second time, apply a photoresist as you image the external layers then pass it through UV light to harden it.
Afterward, you will expose it to a machine that eliminates unwanted photoresists.
- Plating
In this phase, you will apply a layer of thin copper on the PCB through electroplating methodologies.
Afterward, you will conduct tin plating to protect copper paths within the board.
- Etching
Here, you protect copper layers as you eliminate other elements using chemical processes.
This will establish connections, conducting paths, and paths.
- Solder mask application
Ensure the board is clean before proceeding with this process.
Besides, you will apply the epoxy solder mask then solidify it under IV light.
This will give the epoxy resin PCB its distinct color.
- Surface finish
This entails coating the board to enhance the fusing of elements and increase the adhesion quality.
- Silk screening
This entails printing important information about the epoxy resin PCB.
- Testing
Here, you will test the board using various techniques to ensure it meets all design specifications.
- Cutting
This entails cutting pieces of epoxy resin PCB from the main panel.
Is It Possible To Remove The Epoxy Resin That Makes An Epoxy Resin PCB?
Epoxy resin is difficult to remove as it has strong adhesive properties.
Here are processes you can use to eliminate epoxy resin that is hardened:
- Sanding
- Acetone
- Heat gun
- Chemicals
In Which Areas Will You Use An Epoxy Resin PCB?
The various applications of an epoxy resin PCB entail the following areas:
- Medical industries
- Consumer electronics
- Automotive industry
- Maritime industry
- Aerospace industry
- Military industry
- Telecommunications
- Safety equipment
What Mechanical Properties Should An Epoxy Resin PCB Have?
These properties include the following:
- Peel strength
- Flexural strength
- Density
- Delamination time
How Will You Select Materials Suitable For Making High-Frequency Epoxy Resin PCB?
These include:
- PPE resin
These durable options are suitable for making PCBs with frequencies ranging between 1 and 10 GHz.
- Modified epoxy resin
These affordable options are suitable for making boards whose frequency ranges between 1 and 10 GHz.
- Fluorine-series resin
These are the most expensive and are suitable for making boards with a frequency of 5 GHz.
What Will Cause An Epoxy Resin PCB To Fail?
- Acid traps
- Plating voids
- Electromagnetic issues
- Slivers
- Insufficient clearance
- Poor soldering
- Starved thermals
- Unstable components
What Components do Will Make Up An Epoxy Resin PCB?
These include the following:
- Resistors whose job is to prevent current flow by discharging electric power in form of heat.
- Capacitors hold an electric charge temporarily, only releasing it when another part needs it.
- Inductors store energy as magnetic fields which will generate as electric current passes through them.
- Transformers will relay electric energy between circuits, by either increasing or decreasing the level of voltage.
- Light-emitting diodes allow current to flow in a single direction, that is, from anode to cathode.
- Switches that prevent or allow current to flow depending on its status.
- Batteries that offer voltage to circuits.
- Transistors will amplify the charge.
Can You Color The Epoxy Resin That You Use When Making An Epoxy Resin PCB?
Yes, you can include materials to form the color you like, or even purchase pre-colored epoxy resin.
What Are Some Of The Materials You Can Use When Fabricating An Epoxy Resin PCB?
These include:
- Teflon
This material is suitable for high-speed applications and can withstand conditions not suitable for FR-4.
- FR-4
This is a flame-resistant material containing woven fabric and epoxy resin.
- Metal
Here, you will use copper as the main conductive material.
What Should You Consider When Selecting Materials That You Will Use When Fabricating An Epoxy Resin PCB?
These include:
- Purpose
Here, consider the use of the epoxy resin PCB, whether you will use it in high-temperature areas, if you need flexibility, etc.
- Conductivity
Ensure the materials can adequately dissipate heat as overheating is prevalent with high-speed signal products.
- Stackup
This dictates how engineers will make and place the epoxy resin PCB within devices, whether single or multilayer.
- Mechanical strength
Consider if the materials you are choosing are strong electrically or mechanically.
- Signal integrity
Here, you will categorize the function of the epoxy resin PCB as follows:
- Microwave
- High power
- High frequency
- High density
- Flexibility
Using rigid-flex materials makes the epoxy resin PCB foldable depending on the application.
- Component placement
When signal flows past parts that produce noise, it will cause interference, thus jeopardizing the system.
- Cost
Using materials such as gold or vias will increase the cost of the epoxy resin PCB due to extra fabrication processes.
What Chemical Properties Should An Epoxy Resin PCB Possess?
These entail the following:
- Water absorption
- Combustibility
- Methylene Chloride Resistance
What Are Examples Of Layers That You Can Find In An Epoxy Resin PCB?
The layers include the following:
- Substrate layers that support all parts and traces.
- Copper layer that conducts electric current.
- Solder mask layer that has epoxy resin coating and protects the copper from shorts and oxidation.
- Silkscreen layer that gives the PCB its color.
Is There A Difference Between Surface Mount Technology [SMT] And Through Hole Technology [THT] In An Epoxy Resin PCB?
THT entails placing component leads through holes on the bare PCB, thereby forming strong connections.
SMT entails placing components directly on the PCB surface using solder.
What Thermal Properties Can You Find In An Epoxy Resin PCB?
These include:
- Coefficient of thermal expansion
- Glass transition temperature
- Thermal conductivity
- Decomposition temperature
Can You Find An Epoxy Resin PCB With Different Silkscreen Colors?
Yes, you can find them in colors such as blue, green, yellow, red, black, or white.
What Electrical Properties Should An Epoxy Resin PCB Contain?
These include the following:
- Volume resistivity
- Relative permittivity
- Dielectric constant
- Dissipation factor
- Surface resistivity
- Electrical strength
What Is The Future Of Epoxy Resin PCB Materials?
More research is happening on enhancing substrates that you will use when making the epoxy resin PCB.
Also, the need to make lightweight and small epoxy resin PCB increases the demand for the fabrication of high-performance and functional multilayer PCBs.
Besides, there is a new epoxy resin material such as FR-408, Megatron, Getek, and 4000-13.
These materials shape the advancement of the PCBs since they boast a better performance compared to FR-4 materials.
Also, RoHS dictates the need to use materials with more heat resistance and reliability.
Are There Processes That You Can Undertake To Verify The Quality Of An Epoxy Resin PCB?
These include:
- Flying probe testing
This is a cost-effective technique that will inspect the epoxy resin PCB for opens, inductance, capacitance, shorts, diode flaws, or resistance.
- Automated optical inspection
This technique uses cameras to photograph the epoxy resin PCB then compare it to the original schematics.
- Burn-in testing
This intense test will identify early failures and formulate load capacity.
Besides, due to its intensity, it can destroy the parts that you are testing.
- X-ray inspection
Technicians will use this test to identify flaws early in the fabrication phase by viewing traces, connections, and barrels.
- Functional testing
Here, you will verify that the epoxy resin PCB will power up.
We also have a detailed guide on PCB materials.
For any questions or inquiries, contact Venture Electronics now.
