Best PCB Substrate Types For Your Board

Best PCB Substrate Board

Most of the time, the base or the foundation of the PCB board consists of the lamination and the substrate. The distinct kinds of PCB substrates and lamination determine the performance of the PCB board. Hence, choosing the best PCB material for the intended purpose is necessary to achieve the best functionality, cost-efficiency, and longevity. All of these qualities should be part of all PCB design guides, which we will discuss in the following article for the PCB material.

Different Types Of PCB Substrates And Different Results

The PCB substrate material can significantly affect the long and short-term performance and the ability of the contractor to manufacture it. PCB manufacturing is just like anything else. You will get what you paid for. You cannot blame your contractor when you purchase bad PCB material and they fail during the board manufacturing. 

So, what is the best product to use? The PCB Substrate material ranges from FR1 and G-10 to PTFE, Kapton, and alumina. The laminates are made from PTFE, CTE, CEM, and other compounds.

When high performance is not a critical PCB characteristic, a material such as lightweight polyester is the best option. There are two reasons why you should choose lightweight polyester in these cases, as long as it is used with PE technology.

The following are the benefits of PE with lightweight polyester:

• Versatility: the FPCs are accessible in bulk, but the issue is that they are costly when achieving bendability, making them highly beneficial and attractive. PE integrated with lightweight polyester retains flexibility at cost-effective rates.
• Lower Cost: the lightweight polyester produces less waste and has lower processing steps, reducing the need for filtration and water treatment.

However, traditional printed circuit boards are still the top choice for high-performance uses, and the board requirement should determine the type of materials to use for production. For instance, will the PCB:

• Accommodate high power and high temperatures.
• Be dense and complex.
• Handle frequencies between 500MHz and 2GHz.
• Can manage the frequencies at the microwave level or not.

The board’s application determines the types of PCB substrate material or lamination to use.

About TG

In the PCB material, the substrate, temperature, and the lamination’s ability to handle hold the utmost importance in PCBs. High temperature and heat can make the board useless. Hence, heat resistance should be higher than the generated heat. TG is the term given to the glass transition temperature. It is the measurement of the vitrification temperature of the PCB material. Simply put, it is the point at which the printed circuit board will lose its performance and rigidity.

For high-performance boards, the TG is generally higher than 170 degree Celsius. The conventional PCBs come with a TG of 130 degree Celsius. The higher level of TG also shows a greater ability to resist moisture and chemicals.

Moreover, it is also necessary to specify that the TG matches the assembly process. The TG with the lowest 170 degrees Celsius is the best option to get the lead-free assembly.

Some electric manufacturing companies also fill in the blanks for you when you are unsure about the PCB material. For instance, some people say they want the RoHS-compliant PCB but do not provide the TG specification. Some electronic manufacturers determine the best specifications for their customers in these cases.

Guidelines For Choosing PCB Material

The Cost of the PCB substrates and lamination material differs. But it is worth choosing the best and right materials from the outset instead of going through the shame of having expensive PCB failures.

Following are the general suggestions that serve as the beginning point in choosing the materials for the specific substrate and lamination applications:

• FR4: It is broadly used in the standard boards. The TG point of this material is about 135 degrees Celsius. It also comes with the high-TG version, ideal for high-density uses.
• PFTE: it can be the best choice for high-frequency areas such as high-power boards and microwaves with a TG range of 160-280 degrees Celsius.
• CEM-1, CEM-2, and CEM-3: It is known for being the ideal choice for high-density applications. The CEM-1 provides a TG of about 122 degrees Celsius, CEM-2 offers a TG of 125 degrees Celsius, and CEM-3 has a TG level of 125 degree Celsius. 
• The substrate, RF-35, offers a TG of 130 degrees Celsius, which makes it the best candidate for high-density applications.
• Polyimide: when used as the substrate, it offers a TG of 250 degrees Celsius or higher power, microwave solutions, and high-frequency situations. The substrate made up of polyimide is the best option for the flex circuits since the FR4 substrate is rigid. In addition to its flexibility, the polyimide offers high resistance to temperature but is more expensive than the FR4s

Approved Equivalent

In today’s time, it is best to team up with the laminate manufacturing company and specify the material or get the approved alternative of the material you want. Simply put, you will give your contract manufacturer the specific material for use. Still, you will also give it the permission to deviation from that if it is essential, the manufacturing company will get your approval first.

A simple reason for doing this agreement is that a boarding house may provide you the high-quality replacement material, whereas another may provide you with the cheapest junk they can find.

Hence, it is best to communicate your demands as clearly as possible. The FR4 used to be a specific term years ago. In today’s time, it is available in a more standard term. Do not leave the PCB material choices to your manufacturer unless you trust that company completely.

Where Does The PCB Design Go From Here?

Choosing the appropriate lamination and substrate for the PCB application is not always easy. When stepping into the high-density, microwave, or high-frequency world, there is also a delicate balance between cost-efficiency and quality.

How To Choose The Right PCB Manufacturing Company?

When choosing the PCB manufacturing company, the first thing to ask yourself is whether the PCB manufacturing company can work with the specifications you need. This is why you should consider the following things when choosing a PCB manufacturing company:

• Cost: Cost is the primary factor. Reducing the Cost is part of the process of creating a successful product. However, the excitement of the low price is forgotten before the grief of poor quality is overcome. It is necessary to balance the quality and Cost to get a successful product.
• Timescale: meeting the deadline is the primary factor you should consider when choosing the PCB manufacturer. Short-lead-times is the best. However, the quick turn capability with the right solution is necessary.
• Relationships: Another factor to consider is the ability to cooperate and build a relationship. It can be challenging to quantify. However, if the PCB manufacturer can work with the assembly PCB and the designing areas, the synergy will bring major benefits. You should consider it the major factor when choosing the best PCB company. The cooperative relationship can help with the issues to be resolved and help provide feedback in both ways to enhance the productivity and processes that will benefit both parties.

Conclusion

Choosing the right type of lamination and substrate is not an easy task, so you should work with the PCB manufacturing companies that will keep you from getting wires tangled while helping you reduce the PCB assembly costs and the lead time. The more design you work on the PCB layout and assembly, the more chances you will get better recommendations about the PCB materials to use.