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  • Excellent performance in various thermal excursions
  • AOI and UV blocking compatibility
  • Standard FR-4 processing
  • Manufactured through the latest technology

Are there quality certification for Isola FR402?

Yes, there is quality certification for FR402 laminate.
Certificação REACH
Certificação UL
Certificação CE
BSI Certification
Certificação RoHS


What are the applications of Isola FR402?

FR402 is suitable for Automotive and transportation industry. It is best for multilayer PCB applications that requires performance properties surpassing those with epoxy resin function.

In addition, the Isola PCB material can give excellent resistance to thermal and chemical degradation.

What to consider when choose FR402 as material for a design?

Firstly, you have to consider about the cost, Isola FR402 is relatively expensive than other rigid FR4 material.

But FR402 has good performance in terms of middle Glass Transition Temperature (Tg) of 140 degrees Celsius, superior performance through various thermal excursions, extended abilities, which makes it worth consideration for your design.



Risco Isola FR402 is equipped with advanced features such as high thermal performance. It can operate under a Tg – 140°C (DSC) and a Td – 315°C (TGA @ 5% wt loss).  Our Isola FR402 can also offer excellent performance through various thermal excursions.

It is also equipped with resistance to measling and extended capabilities to give you the best performance and solution to your PCB requirements.

Seu fornecedor líder de Isola FR402 na China

Venture Isola FR402 is consists of a modified tetra functional epoxy resin system. Our Isola FR402 is engineered specifically for any multilayer applications that need performance that exceeds the functional epoxies performance characteristics.

Venture Isola FR402 is equipped with advanced features such as high thermal performance. It can operate under a Tg – 140°C (DSC) and a Td – 315°C (TGA @ 5% wt loss).

The formulation of Venture Isola FR402 is designed specifically to help in the accuracy of laser-based AOI and improving the throughput equipment. Venture Isola FR402 offers excellent thermal degradation and resistance to the chemical.

Our Isola FR402 can also offer excellent performance through various thermal excursions. It is also equipped with resistance to measling and extended capabilities to give you the best performance and solution to your PCB requirements.

Aside from that, we manufacture Isola FR402 with AOI compatibility and UV blocking. Our Isola FR402 also undergone the standard FR-4 processing.

Isola FR402: The Ultimate FAQs Guide


In this guide, I will answer all questions you have been asking about Isola FR402.

Whether you want to learn about the treatment options, advantages, features, or quality, you will find all information in this guide.

Continue lendo para aprender mais.

What is Isola FR402?

FR402 is a laminate and prepreg system by Isola that comprise of an improved tetra-functional epoxy resin system.

A Isola laminate is best for multilayer PCB applications requiring performance properties surpassing those of di-functional epoxy resin systems.

The design of Isola FR402 construction enhances the throughput and precision of laser-based AOI equipment.

Moreover, the Isola PCB material gives superior resistance to thermal and chemical degradation.

Isola FR402

 Isola FR402

What are the Key Features of Isola FR402?

Here are the main properties of FR402 PCB material:

  • Available in thicknesses from 0.05 mm (0.002″) to 3.2mm (0.125″)
  • FR402 laminate Comes in panel or sheet form
  • Copper foil cladding include HTE, Reverse-Treat and Double-Treat
  • Uses glass styles including 106, 1080, 1652, 2113, 2116, 2313, 7628, 7629
  • FR402 Prepreg available as panel or roll
  • Has flammability rating of UL94 V-0

Which are the Acceptable Treatments for Isola FR402?

The treatments allowable for sufficient bonding of FR402 epoxies include double treat copper, red oxide, brown oxide, and black oxide.

However, in case you use black oxide, the oxide ought to be self-limiting to prevent excessive oxide crystal.

Moreover, you can as well achieve sufficient bond strength using the variety of alternative and reduced oxides available.

Talk to your chemical supplier about post oxide baking aspects when you employ alternative or reduced oxides.

This is because extreme baking may lead to reduced pink ring resistance.

Furthermore, inner layers need to undergo thorough drying inside an oven before lay-up.

The usual bake cycles, which range from 200 to 250 degrees Fahrenheit for 30 to 60 minutes are allowable.

It is advisable to carry out the baking in upright racks having panels held up in a vertical position.

What is the meaning of Etch Factor in Fabrication of Isola FR402?

An etch factor refers to a process modification performed by PCB fabricator to recompense for the process of chemical etching.

Being a subtractive process, the chemical etching operation removes copper gently when creating the circuit pattern.

When you require an Isola PCB with track width of 0.127 mm, you will have to begin with a broader track.

The value you increase the track by represents the etch compensation or etch factor.

Additionally, the etch factor is proportionate to the weight or thickness of copper you will remove.

The more copper you etch, the greater the etch factor.

What is the Recommended Cure time for Isola FR402?

Multilayer PCB thickness

 Multilayer PCB Thickness

The thickness of the multilayer PCB you intend to produce will determine the cure time for the FR402 material.

The multilayer PCB thickness to some extent also determines the cure temperature.

Very thick Isola FR402 multilayer PCBs will need a prolonged cure time to attain optimal material performance.

Further, you should remove the FR402 flash through routing instead of shearing to reduce crazing along the edges of the panel.

Which is the Best Between Single-Stage Press and Dual-Stage Press for the lamination of Isola FR402?

The lamination cycle you choose will depend on the board stack-up, thickness and complexity coupled with the capability of lamination presses.

Thicker boards might need extra dwell time at cure temperature to attain full cure.

Selecting a “kiss” cycle or dual-stage for FR402 multilayer circuit boards might boost outcomes in some applications.

Employ these cycles to improve the glass wetting along with the corners and extreme edges of the panel.

Moreover, you can as well use a dual-stage press to reduce telegraphing (circuit image transfer) on foil constructions.

Nonetheless, all types of lamination presses incorporate a pressure reduction stage within the lamination cycle.

This allows the package to relieve stress during the curing of the Isola FR402 laminate.

Also, the two lamination cycles assume that the lamination press maintains a vacuum all through the heating cycle.

Moreover, they assume that the book cooling occurs at a temperature below the Tg of the FR402 before opening the press.

All these three conditions symbolize “best practice” standards during the lamination of Isola FR402.

What is the Role of Epoxy Resin System in Isola FR402?

The resin system serves as a load transferring agent and binder for the Isola FR402 laminate.

It primarily comprises of bi-epoxies, tetra-epoxies or multifunctional epoxies.

You can include additives such as accelerators, fillers, flame retardants and curing agents to the resin system.

These additives are instrumental in improving the properties of the FR402 material.

Curing agents like phenol novolac phenolic) and dicyandiamide are helpful in enhancing the cross-linking of the laminate’s epoxy matrix.

Phenolic-cured epoxy resin system features better thermal resistance, humidity resistance, chemical resistance and enhanced mechanical properties.

However, DICY-cured epoxy resin system features have more desirable processability (for example drilling) than phenolic-cured ones.

You add flame retardants to the epoxy resin system to minimize the flammability of the FR402 laminate.

Most PCB laminate manufacturers use phosphorus-based compounds as halogen-free flame retardants for FR402 resin systems.

Laminado de PCB

Laminado de PCB

Adding fillers like aluminum hydroxide and silica to the resin system lowers the coefficient of thermal expansion of the FR402 laminate.

Furthermore, the filler also enhances the flame retardancy and minimize the costs of materials.

On the other hand, accelerators are instrumental in controlling the cross-linking density of the resin system. And the curing rate.

What are the Main Causes of Outgassing in Isola FR402 Laminate?

The circumstances under which outgassing happens may differ, however, its causes are the same irrespective of where it occurs.

Here are the two main reasons for outgassing in FR402 boards:

· Incorrect Materials

When selecting Isola PCB materials, you must consider each stage of the board’s life, including manufacturing and application.

Plating formed from tin, silver, or gold can consist of organics or salts that produce gas if heated during deposition.

Outgassing risk increases when an FR402 board utilized in high-vacuum environments consists of materials with a higher chance of outgassing.

· Faulty Manufacturing

The process of manufacturing dictates the Isola PCB quality just as its materials.

Outgassing when soldering frequently occurs if you perform the pre-heat process improperly or apply a very thin electroless copper plating.

Failure to eliminate moisture during the manufacturing of FR402 can produce the vapors related to off-gassing in high-vacuum applications.

What the Advantages of Isola FR402?

Here are the key benefits of using Isola FR402 in your PCB projects:

  • High Glass Transition Temperature (Tg) of 140 degrees Celsius
  • Superior performance through various thermal excursions
  • Resistance to measling
  • Extended abilities
  • UV Blocking and compatible with AOI devices.
  • Processes as a conventional FR-4

Which are the Types of Curing Agents Used in Isola FR402 Laminate and Prepreg?

Addition of curing agents to the FR402 resin system help in enhancing cross-linking thus thermosetting the Isola laminate.

They are often cycloaliphatic or aliphatic amines and amides or polyamines.

The properties of the two commonly used curing agents in Isola laminates differ due to their inherent molecular structures differences:

· Dicyandiamide (DICY)

DICY-cured epoxy resin systems comprise of linear aliphatic molecules.

The key properties of DICY curing systems include good adhesion, better flexibility, and outstanding processability.

Nevertheless, this curing agent type for FR402 laminates features poor anti-CAF ability, higher water absorption, and poor thermal resistance.

They are more hydrophilic compared to phenolic-cured systems because of the existence of exceptionally polar carbamide-carbamide bonds within their chemical structure.

Moreover, the powerful polar nitrogen atom found within the DICY-cured system might weaken the brominated epoxy resin at elevated temperatures.

This leads to the creation of corroding bromide ions.

· Phenol novolac (Phenolic)

The phenolic curing system and its cured epoxy resin systems feature an aromatic structure.

Due to this fact, phenolic-cured FR402 resin systems are more thermally steady in comparison to DICY-cured systems.

Further, because of their aromatic structure, PN-cured epoxy resin also has low moisture absorption, high chemical resistance, and enhanced mechanical features.

They as well have the good anti-CAF ability.

Nonetheless, this type of curing agent for Isola FR402 has poor processability in comparison to the DICY curing system.

How do you Test the Quality of Isola FR402?

Let’s look at the most important quality tests for FR402 PCB laminate material:

· Peel Strength Test

Typically, lamination quality tests will examine the resistance of the FR402 laminate to peeling by application of force or heat.

It is vital since the quality of lamination is key to the PCB lifespan.

Peeling laminate may lead to problems in the performance of the ultimate product.

· Water Absorption Test

Absorption of moisture can result in delamination or other harm in the Isola FR402 board exposed to soldering heat.

The test examines the moisture absorption rate and bulk moisture content of FR402 PCBs.

· Contamination Testing

This quality test senses bulk Ionics, which might contaminate your circuit boards leading to abrasion and other problems.

· Thermal Performance Test

Often, PCB manufacturers determine the thermal performance of a board through its glass transition temperature (Tg).

You can measure glass transition temperatures effectively through Differential Scanning Calorimetry (DSC), Thermomechanical Analysis (TMA) or Dynamic Mechanical Analysis (DMA).

Is Isola FR402 RoHS Compliant?

Yes, FR402 laminate is compatível com RoHS.

This means it does not incorporate the hazardous substances restricted by Directive 2002/95/EC.

The restricted substances are polluting landfills, making them dangerous to the environment.

Moreover, they are hazardous with regard to occupational exposure during Isola laminate production and recycling.

What is the Difference Between Glass Transition temperature (Tg) and Decomposition Temperature (Td) of Isola FR402?

Glass transition temperature refers to the temperature where the resin system changes from solid-state to a plastic state.

The transition occurs because of the disintegration of the bonds interlinking the molecular chains of the epoxy resin.

The Tg of FR402 laminate system basically relies on the percentage composition and type of epoxy resin.

Conversely, decomposition temperature refers to the temperature where the resin system undergoes irreversible chemical and physical degradation.

At this temperature, there is thermal elimination of cross-links, loss of weight by the Isola FR402 laminate material.

What is Glass Weave Effect in FR402 Laminate?

All Isola FR402 laminates incorporate woven fiberglass to offer structural strength.

It helps in the mechanical reliability of the Isola laminate, nevertheless, fiberglass reinforcement influences the electrical properties of the laminate.

The impacts of the fiberglass on the electrical features of the FR402 is the Glass Weave Effect.

It can cause negative effects on the electrical functionality of high-frequency or high-speed boards fabricated using woven fiberglass reinforced laminates.

The structure of various glass weaves create some gaps within the Isola laminate that get filled by resin system.

It is these gaps, which you can observe under a microscope, that basically result in the glass weave effect.

There is variation in dielectric constant when you pass a signal along the interconnect length.

It is the gaps in the FR402 laminate that cause the signal velocity variations as it travels across an interconnect.

These signal velocity variations are what lead to fiber weave effect in the PCB laminate.

The primary for of glass weave effect include skew, cavity resonance, dispersion, and losses in the Isola FR402 laminate.

Why is E-glass the Best Glass Fabric for Isola FR402?

The most popular glass fabric material utilized currently in the manufacture of PCB laminates is E-glass.

It is a continual filament glass yarn having a chemical structure by weight of mainly SiO2.

However, it can as well consist of various quantities of Al2O3, CaO and other materials.

E-glass is the best glass fabric for FR402 because of its high water resistance, tensile strength, and bond steadiness with resin.

In addition, it is a relatively low cost.

Though it has a high dielectric constant, it is acceptable for the majority of low-frequency Isola PCB applications.

How Do you Handle Isola FR402 During Lamination?

You should note that the process of lamination is in itself a dehumidifying procedure.

In the process, you glue together the FR402 laminate and prepreg before placing it into the press to produce the final laminate.

The PCB lamination press controls the heating rate, cure time, and cure temperature.

Often, there is an introduction of a low temperature, low pressure (vacuum) step to reduce the development of internal cavities.

These cavities are preferential locations for moisture entrapment, which might affect the performance of the final product.

During the lamination of FR402, you should only handle the prepregs by the edges utilizing clean nitrile or latex gloves.

This prevents scratching, damage and cross-contamination of differing types of epoxy resin, but do not reuse gloves to avoid cross-contamination.

Promptly reseal and store the moisture barrier bag (MBB) holding the left unused resin horizontally inside a cool, dry environment.

Generally, the storage condition should be 23 degrees Celsius or below and 50 percent RH or lower.

Moreover, make sure the MBB has sufficient seal width and the desiccant materials need to be dustless and non-contaminating.

During selection, it is also important to consider the environmental aspects during shipping.

Ensure that the humidity indicator cards (HIC) are non-corroding and have sufficient number of sections to solve varying humidity levels.

Additionally, give the prepregs enough time to acclimate to the surrounding environment before layup.

Perform the acclimatization by holding the prepreg inside the MBB through the stabilization duration to prevent the condensation of moisture.

Bare, uncoated FR402 laminates an equally higher rate of moisture absorption in comparison to those having solder mask cover.

Furthermore, the duration and number of wash cycles also influence the moisture uptake by the PCB material.

Nonetheless, short period wash cycles of Isola FR402 laminates stored in controlled conditions are not always a problem.

This is the case if you closely space in time the succeeding steps.

Most PCB manufacturers have always baked prepregs before lamination.

Baking of FR402 aids in reducing extreme shrinkage and avoid the development of cavities for moisture to collect and form blisters.

It is justifiable to conduct the bake in case you stored the FR402 prepreg in uncontrolled conditions for prolonged periods.

However, this bake stage is not necessary in most lamination process.

What are the Effects of Moisture on Isola FR402 in Multilayer PCB Application?

Moisture can decrease the quality of lamination, solder mask, metallization, and associated steps in Isola PCB manufacturing and assembly.

Below are some of the common problems related to moisture absorption by FR402 laminates.

Knowing these effects is vital in choosing the most suitable approach for minimizing moisture in the circuit boards:

  • Entrapped moisture can lead to delamination of the inner layer or blistering.
  • Extreme moisture increases dissipation factor (Df) and dielectric constant (Dk), causing alterations in circuitry switching speed.
  • Since moistures serve as a plasticizer, it lowers the glass transition temperature. As a result, it increases stresses on the components of the FR402 PCB like plated thru-holes.
  • Moisture causes copper surface oxidation resulting in poor wettability of solder and finishes.
  • Ionic corrosion due to moisture leads to electrical shorts or opens.
  • Interfacial degradation because of moisture can cause the decreased time to failure, as a result of conductive filament formation (CFF).

What is the Purpose of Laminate Witness Coupon (LWC) in FR402?



The use of laminate witness coupon is becoming very popular lately.

You can use LWCs as a guide to assess the relative moisture absorption and status of the Isola laminate.

It helps to evaluate the moisture condition of the FR402 board during the many steps in the PCB assembly process.

You measure and record the LWC weight before putting them inside the moisture barrier bag together with laminates.

Make sure to always place the LWC on top of the Isola FR402 laminates.

Immediately after receipt, evaluate the LWC for moisture absorption by weighing it utilizing an analytical balance.

Compare the result to the original recorded value.

Bake the LWC until dry in case the moisture absorption surpasses the designated limits to validate the outcome.

Also, inform your FR402 laminate supplier if the values surpass the specified limit.

The supplier will advise on the right next steps.

What is the Standard Board Thickness when Drilling Multilayer Isola FR402?



Hit counts and stack heights will differ depending on the construction and general thickness of FR402 board you are drilling.

You can successfully standard boards of 0.060″ thickness 3 high for up to 13.5 mils bit diameters.

As a general rule, the total board thickness in a multiple layer drill must not surpass 200 mils.

In the case of a small drill diameter, the maximum hit count is 1000.

However, for 13.5 and above drill diameters, the maximal hit count is 1500.

At Venture Electronics, we give you the best Isola FR402 material that meet specific needs of your applications.

Para qualquer dúvida ou consulta, entre em contato com a Venture Electronics agora mesmo.

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