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Why should you select FR4 Printed Circuit Boards for Electronic Applications?

By | Date posted: | Last updated: January 17, 2022
FR4 Printed Circuit Boards

PCBs are an integral part of all electronic appliances. The choice of material of the PCB, however, depends on a number of factors including the environment in which the PCB has to function. Of the many materials used to make custom printed circuit boards, FR4 has emerged as a popular material. Not without reason. Here are the many reasons and aspects about FR4 that you need to know to be able to make the right choice:

What really is FR4 Material?

FR4 is a fiberglass reinforced epoxy laminated sheet, with the FR in FR4 standing for flame retardant. On account of the fiberglass, the material is known for its structural stability. The fiberglass, in turn, is covered with the flame resistant epoxy resin. FR4 is known for its strong mechanical properties as well as durability that explain its widespread use.

Examples of FR4 include:

Standard FR4: It is known for its heat resistance of the order of 140°C to 150°C.

High TG FR4: It has a higher glass transition (TG) of around 180°C.

High CTI FR4: Its Comparative Tracking Index is higher than 600 Volts.

FR4 with no laminated copper: It is ideal for insulation plates and board supports.

Properties of FR4 Material

Let us look at some of the other properties of FR4 material that result in its widespread popularity:

  • It has high dielectric strength and hence high electrical insulation properties.
  • It is known for its lightweight and thus finds extensive use in today’s environment where miniaturization is key.
  • It is moisture resistant and finds use in a wide variety of applications where moisture in the environment is a given.
  • It is known for its cost efficiency. Other laminate material like ceramic or Arlon comes at a higher price and can impact your overall project.

FR4 Printed Circuit Boards Types Based on Classification

FR4 printed circuit boards are classified based on several attributes. Some of these include:

Size or Thickness

While the standard FR4 thickness is 0.78 mm, it is available in a wide variety of thickness. Copper clad FR4 boards are available in 18µm to 140µm

Source of FR4 Material

FR4 Printed Circuit Boards are available in types such as Rogers FR4 PCB, FR4 Isola PCB and more basis the manufacturing companies.

Thermal Properties of FR4 Printed Circuit Boards

Glass Transition Temperature

The standard FR4 material has a glass transition temperature of 130 to 140 centigrade. However, factors such as coefficient of expansion, dielectric value, and others determine its standard nature.

The glass transition temperature value of an RF4 material determines the kind of application in which it can be used. An FR4 that has high glass transitional temperature can withstand far higher frequencies. Such material can also withstand high operating temperatures.

Decomposition Temperature

It is the temperature at which the FR4 PCB sheet is permanently decomposed. The FR4 Printed Circuit Board decomposition temperature comes at the highest TG value of 180 degrees centigrade. Beyond this point, the FR4 changes its chemical properties permanently.

How to select the right FR4 material for your printed circuit boards?

Here’s how to make the choice of FR4 material for your PCB:

  • Thin FR4 material comes in handy where you have a space constraint. Not only can the thin material support delicate components, it also works well for space saving designs.
  • Once again thin FR4 material works for applications that demand flexibility. It is therefore widely used for automotive and medical PCBs.
  • On the other hand, for designs that have grooves, thin material needs to be avoided on account of the high risk of damage.
  • Needless to mention that the thickness of the material impacts the weight of the PCB. Where miniaturization and lightweight of the electronic appliance are a requirement, thin FR4 boards need to be chosen.

To Sum Up

With a wide variety of FR4 material available in the market with diverse capabilities, it is easy to choose the right PCB material that suits your bespoke needs. The boards created using FR4 material are strong, durable and water-resistant besides offering insulation, reducing interference and backing excellent signal integrity. Your PCB Contract manufacturer will be in the best position to guide you through your choices.

Our experienced PCB material management team and advanced material management system can efficiently manage your projects and requirements. We have the resources available to locate parts and materials you need to eliminate the delay and reach quickly to the result.

Request a quote to inquire about our PCB assembly and manufacturing services.

What is the difference between PCB DFA, DFM and DFMA?

By | Date posted: | Last updated: January 5, 2022

With a large percentage of production costs being determined by design decisions, it stands to reason that Design for Manufacturing has come to occupy a huge role in manufacturing. What, however, are the differences, if any, between Design for Manufacturing, Design for Assembly and the more comprehensive sounding Design for Manufacturing and Assembly? Let us take a deep dive and find out.

PCB DFA vs DFM vs DFMA – What do these terms stand for?


Design for Manufacturing is a design method that goes a long way in reducing the complexity of manufacturing operations. It also has a positive implication on the overall cost of production including the cost of raw materials.


Design for Assembly is a design method that facilitates the assembly operations of components of a product.


Design for Manufacturing and Assembly is an engineering technology or method that prioritizes both ease of manufacture as well as simplified assembly of the parts, during the early design phases of the product lifecycle. It, therefore, helps bring down time-to-market as well as total production costs. As a singular philosophy, it brings together what was so far considered to be two distinct methodologies, namely DFM & DFA.

Main levers to reduce manufacturing costs through Design for Manufacturing and Assembly (DFMA)

Given that DFMA is a comprehensive, balanced approach that combines DFM & DFA practices, let us look at what are some of the main levers when it comes to reducing PCB manufacturing costs through the DFMA approach.

Reduction in number of parts

Reducing the number of parts not only reduces the cost of PCB assembly, it also has an implication of a number of other costs including but not limited to:

  • Administrative and logistical costs
  • Cost of testing and reliability

Using Standard Parts

Using standard parts as opposed to customized ones can prove to be more cost-effective. The fact that they are easily available also adds to ease of production.

Adopting a Modular Design

The use of modules offers a wide range of benefits including:

  • Reducing the number of components. This also reduces the indirect costs.
  • Reducing redesign costs by using existing modules.
  • Taking advantage of production scale for modules that are common.

Modularity, however, is limited by the increase in PCB assembly costs with an increased number of connections.

Designing Multifunctional Parts

Use of a multifunctional part reduces the need for an increased number of parts.

Error-proof parts

This involves designing parts that cannot be assembled in the wrong way or be assembled on other products.

Designing Parts to facilitate Assembly

Parts can also be designed to facilitate assembly as well as testing.

Limiting Tolerance Constraints

It is important to ensure that the binding tolerances are reduced, and any over-specifications aren’t followed, as these could result in higher costs on account of the following:

  • Need for more robust processes.
  • Need for sophisticated equipment.
  • Need for extensive quality control.

Limiting Fasteners

As a thumb rule, separate and complicated fasteners need to be limited as they increase costs.

Facilitating Handling

The parts need to be designed in a manner such that they are easy to handle. Sharp edges, parts that are too large etc. for example are best avoided from the handling perspective.

Reducing Assembly Directions

Wherever possible all the parts need to be assembled in one direction.

Design For Manufacturing and Assembly Methods

There are a wide variety of methods that aid DFMA. Noteworthy among the following are:

  • Collaboration between design and manufacturing teams. It is important that all stakeholders are a part of the process so that there are no last-minute surprises.
  • Design for Testability, to ensure that it is easy to test while in production. This is often a part of the Design for Manufacturing mandate.
  • Design for Maintainability, which ensures easy, less costly maintenance for manufacturing equipment and which ensures there is no downtime.

To Sum Up

DFMA, a combination of Design for Manufacturing (DFM) and Design for Assembly (DFA), enables a product design to be efficiently manufactured and easily assembled with minimum labor cost. Through the use of DFM best practices as well as DFA, a company can do the following:

  • Prevent manufacturing inefficiency.
  • Eliminate waste.
  • Not dealing with costly errors.

For effective application of DFM/A, the two activities must work together to ensure success.

Mer-Mar Electronics is one of the leading PCB design and manufacturing companies, providing all in one PCB assembly and fabrication solutions. Our consistent quality and quick turnaround endear itself to our customers, who look on us as a one-stop-shop for all their PCB manufacturing requirements. In case if you have any questions or require more information about PCB assembly and fabrication services, contact us via or call us on (760) 244-6149.

What are the Pros and Cons of Immersion Silver PCB Surface Finish?

By | Date posted: | Last updated: January 12, 2022
Immersion Silver PCB Finish

Before we delve into the relative merits and demerits of Immersion Silver as a surface finish, it will be worthwhile to define what a surface finish exactly is and the functions it performs.

PCB surface finish is typically applied to exposed copper conductors and connectors on the PCB. It performs several important functions, primary among them being that it serves as a protective layer for the copper connectors during storage. It also ensures good solderability between the PCB and the components during PCB assembly. Post assembly, it helps preserve the integrity of the solder joint.

Commonly used surface finishes include:

  • Hot Air Solder Leveling (HASL)
  • Organic Solderability Preservative (OSP)
  • Immersion Tin (ImSn)
  • Immersion Silver (ImAg)
  • Electroless Nickel/Immersion Gold (ENIG)
  • Electroless Nickel/Electroless Pd/Immersion Gold (ENEPIG)

Each of these come with their own set of advantages. Let us look at Immersion Silver as a surface finish in some detail.

Immersion Silver as a surface finish

Immersion silver also popularly known as IM silver, IMag or ENIAg is a popular surface finish when it comes to PCBs. Essentially, it refers to depositing a thin layer of silver on the copper finishes of the custom printed circuit boards. The chemical reaction involved is a displacement reaction where silver and copper are spontaneously displaced.

Everything you need to know about Immersion Silver

Essentially, Immersion Silver is a transitional technique between OSP & ENIG when it comes to performance. Immersion silver is high on solderability and solder joint strength, however it is not as strong as gold when used as a contact surface.

As far as the process goes, the displacement reaction sees a pure silver coating at a sub-micron level. The Immersion silver finish is known for its electrical properties and its excellent weldability even when it is exposed to heat, moisture and contamination. Of course, in terms of physical strength it cannot compete with ENIG. Also, another drawback of Immersion Silver is the electron migration of silver. When exposed to moisture and on application of voltage, silver is prone to electromigration. To circumvent this problem, it is advisable to add organic compounds to the silver.

Pros & Cons of Immersion Silver PCB Surface Finish


  • Immersion Silver is known for the immersion finish and flatness that it offers. Especially as opposed to HASL finish, its advantages totally stand out.
  • That it is lead-free and RoHS complaint works in its favor.
  • It is known for its low loss for signal integrity applications.
  • On account of its tighter tolerances, it can be held for plated holes.
  • It works particularly well when it comes to fine pitch, BGA PCB assembly and small components.
  • In terms of costs too, it works well when it comes to its lead-free finish.
  • Given proper packaging, it has a decent shelf life when it comes to storage.
  • That it is reworkable, adds to its repertoire of advantages.


  • When it comes to handling, it requires a lot of sensitivity. Without the use of gloves, it can lead to tarnishing issues.
  • It requires specialized packaging. Also, once the package is opened and all boards aren’t used, immediate resealing is required.
  • A disadvantage of this coating also stems from the fact that there is a short window between assembly stages
  • Also, the supply chain options for this finish are limited.
  • While it is more cost-effective than ENIG, it is less cost effective than Immersion Tin.

Use Cases of Immersion Silver PCB Coating

  • It works well for products with high-speed signals. It therefore finds extensive use in industries such as automobile, computers, communications.
  • It is a great option when it comes to complex PCBs with QFN or BGA packages.
  • PCBs built for commemorative purposes benefit from Immersion Silver surface finish.

To sum up

Immersion silver works well on account of its flatness as well as joint strength. That it is a cheaper option compared to ENIG, makes it a preferred finish. Immersion Silver is also known for its electrical properties and for its use in high-frequency signals. It is also the coating of choice on account of its ease of assembly as well as easy inspectability.

It is its sensitivity to tarnishing and voids in solder joints that restricts its application.

Mer-Mar Electronics is an ISO 9001:2015 certified company and ITAR (International Traffic in Arms Regulations) compliant manufacturer that delivers PCB manufacturing services with specialized support, reliable testing, and multi-functional features. Our consistent quality and quick turnaround endear itself to our customers, who look on us as a one-stop-shop for all their PCB requirements. In case if you have any questions or require more information about PCB assembly and fabrication services, contact us via or call us on (760) 244-6149.

Custom Printed Circuit Boards: Top Advantages and Disadvantages

By | Date posted: | Last updated: December 17, 2021
Custom Printed Circuit Boards

Increasingly, electronic devices call for complex circuitry in a limited space. With miniaturization of devices, you need to use small electronic components and make every attempt to save space. Little surprise then that you cannot make do with standard PCBs that are available and need to opt for custom printed circuit boards that can do justice to your bespoke requirements.

Custom printed circuit boards (PCBs), however, come with their advantages as well as disadvantages. Let us delve into them in detail:

Pros of Custom Printed Circuit Boards


First things first; size is one of the most crucial factors when it comes to custom printed circuit board services. A conventional circuit board may not be able to meet the exact requirement of your electronic appliance. However, if you opt for a custom printed board, you can get not just the exact size but also the shape required by you. The advantage of space-saving, condensed circuitry cannot be overstated. This is something that you can achieve with a custom PCB.


With conventional circuit boards you may face the issue of them being broken easily. Additionally, the wiring they come with often loosens up. With a custom PCB you can rest assured that durability isn’t compromised. With accuracy and quality of custom PCBs being maintained, the reliability of the electronic device is a given.


Since you are getting the PCB designed to your unique requirements, what you also tend to gain is the professional look and feel of the PCB. All parts are spaced evenly and there isn’t any exaggerated wiring. Besides, you could also have interesting artworks added as per your choice.


While the mutual understanding is that the cost of a custom PCB is higher than that of a standard PCB, in the long run this isn’t always true on account of the following factors:

  • Custom printed circuit boards typically require less rework and hence if you look at long term costs, you are clearly talking about cost savings.
  • Once the PCB has been designed and built, the schematics, Gerber files and bill of materials can be used to build another prototype at a low cost.
  • With the ability to recycle schematics for future iterations of the same device, you tend to save device time & cost for the future.

Some of the other advantages of custom printed circuit boards include:

  • Direct printing legends eliminates the need for decals.
  • Integrated LED lights provide easy verification of its functionality.

Cons of Custom Printed Circuit Boards

This is not to say that custom PCBs do not come with their own set of challenges, notable among them being:

  • The initial design time as also the tooling required is high. In case you are working on extremely tight timelines custom PCBs may not work well.
  • It is difficult to revise custom PCB multiple times.
  • Troubleshooting can sometimes get difficult, particularly if you have enclosures to protect the PCB from the working environment.
  • With rapid changes in PCB technology, the components can become obsolete quickly. In such cases, it becomes very hard to repair or replace them.
  • Custom PCBs aren’t particularly suited for low volume applications, particularly those that change often. In cases where your design is revised frequently or the custom low volume PCB assemblies are such that they don’t really bring a return when it comes to design or tooling costs, it isn’t an ideal option.

Are custom printed circuit boards right for your industrial requirements?

The answer to this question lies on a number of factors that include:

  • The complexity of the project.
  • The volume.
  • Your budget.
  • Commitment to quality.

While custom PCBs require a commitment to a particular design, take some time and minor upgraded cost (although it depends on your requirements). They also come with an inherent robustness, offer the ability to recycle a PCB design and significantly reduce the cost of rework. You can select the best option by analyzing your requirements.

What can an electronics contract manufacturer offer you?

An experienced electronics contract manufacturer can produce custom PCB assemblies, box builds as well as cable assemblies. They can also help test at the board level as also test capabilities of the box build, as required.

In case you already have a custom printed circuit board design available with you, a contract manufacturer can help with:

  • Assembly that conforms to industry standards.
  • Testing PCB and the components using state-of-the-art testing methods.

At Mermar Electronics, we have years of experience in custom PCB assembly. We cater to a wide range of industries and their unique requirements while following the highest quality standards and being RoHS (Restrictions of Hazardous Substance) compliant.

With consistent product quality, quick turnaround time and excellent customer service, you can count upon us to meet and exceed your requirements. Whether your requirement involves simple boards or complex multilayer ones, we offer prototyping as well as custom production facilities, catering to your volume requirements. From offering Design for Manufacturing checks to having your design manufactured, we are a one-stop shop for custom PCB production that you can rely upon.

Get a free quote by submitting your requirements via PCB assembly quote form or get in touch with us via email at or call us at 760/244-6149.

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