Does Your PCB Need Underwriter’s Laboratory (UL) Certification?

February 14, 2019 , in Blog

Whether it’s the logo on our clothes, the name on our golf clubs, or the brand of food that we eat, having that identification on those items assures us that there won’t be any surprises. The clothes will fit, the golf ball will soar, and the food will be delicious because they are identified as being something that we trust. We all understand that when it comes to those consumer products, but we also want to generate that the same level of trust in the printed circuit boards that we are designing that will be used in different applications.

Compliance, regulations and standards documentation in UL certification

This can be accomplished by submitting our PCB designs for product testing and certification. The most widely recognized testing organization is Underwriters Laboratories (UL). With the UL certification on your PCB, you can assure your customers that the board that they are getting is safe. It has been certified as safe to use and has followed specific standards and guidelines in its development and construction. But do you always need this certification? Let’s take a closer look.

Why Should Your Design be Tested and Certified?

Certification means that your PCB has been tested and verified to meet specific standards for safety. While this isn’t a warranty or guarantee of performance, it nevertheless instills confidence in your customers that the board that they receive from you matches or exceeds industry standards for the prevention of electrical shock or fire. Many end products now also require that PCBs be built to these standards. Some examples of the industries that have these kinds of requirements are medical equipment, audio and video equipment, and industrial control equipment, to name a few.

If you are building PCBs for an industry that doesn’t have this requirement, then you may not need to have your board certified. This is also a marketing decision as having your board certified may make it a more attractive option than what your competitors have to offer. In any case, officially certifying that your board was built according to industry safety standards may offer you some protection in cases of liability as opposed to not having that certification.

What is Underwriters Laboratory (UL) Certification?

One of the most well-known organizations offering product safety certifications is Underwriters Laboratory. This is a global safety consulting and certification company that was established in 1894. They test products, document standards, and certify manufacturers in a wide range of industries. Having a UL logo on your board certifies that your PCB has been verified to have been designed according to UL standards for quality and safety.

Underwriters Laboratory works with many different industries and has some 1300 standards that have been accredited by the American National Standards Institute (ANSI). Out of these hundreds of different standards, here are the standards that apply directly to PCBs:

UL Standards for PCBs



UL 796 Printed Wiring Boards

For standard rigid, metal-based and HDI PCBs

UL 796F Flexible Materials Interconnect Constructions

For flexible and flex-rigid PCBs

746E Polymeric Materials

For  industrial laminates and materials used in PCBs

UL 746F Polymeric Materials

For flexible dielectric film materials

UL 94

For flammability of plastic materials

Getting Your PCB Certified

The parameters for your PCB certification will be determined by the application of the board in the end product it is designed for. As we mentioned earlier, certain industries such as medical equipment have specific standards that must be met and certified in order for your board to be used. The parameters include the following:

  • Specific flame rating
  • Maximum operating temperature (MOT)
  • Direct support requirements (DSR) compliance
  • Minimum comparative tracking index (CTI) rating

If this is information new to you or you’re having trouble deciphering the applicability of various standards, help is available. Underwriters Laboratory has an engineering staff that can help you to determine what parameters you need to design for in your PCB.

Another source of assistance is your contract manufacturer (CM). They can help you determine which parameters you need certification for. They can also support you throughout the process of getting your boards set up and sent out for testing and certification.

Tempo‘s Custom PCB Manufacturing Service
  • ISO-9001, IPC-600 and IPC-610 commitment to quality certifications.
  • Accurate quote in less than 1 day.
  • Performs entire turnkey process in as fast as 3 days.
  • Emphasizes DFM to eliminate time-consuming back-and-forth design corrections.
  • Sources components from the most reputable suppliers in the industry to reduce procurement time.
  • Performs multiple automated inspections during assembly to ensure PCB quality for prototyping.
  • Provides support throughout the PCB manufacturing process, beginning with design.
  • Smooth transition from prototyping to production.

At Tempo Automation, we can help you with your PCB design. We are ready to work with you on your board certification process, as well as answer any other questions to help you create your design.

And to help you get started on the best path, we furnish information for your DFM checks and enable you to easily view and download DRC files. If you’re an Altium user, you can simply add these files to your PCB design software.

If you are ready to have your design manufactured, try our quote tool to upload your CAD and BOM files. If you want more information on how to get UL certification on your PCB or how to incorporate your design into a CAD format, contact us.

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