Security is essential in the electronics industry. It is vital that users can rely on the finished products when considering factors such as fire and electrical safety, which means that both the PCB and the materials they contain must measure up to the highest standards. To ensure that the boards do conform, it has become common practice to UL-certify the constituent materials or the PCB itself. In this column I am going to discuss UL certification, what’s involved and why you need it.
The acronym UL stands for Underwriter's Laboratories. Founded in 1894, UL is a globally recognized organization headquartered in the United States with locations all over the world . UL describes itself this way: “As the global safety science leader, UL helps companies to demonstrate safety, enhance sustainability, strengthen security, deliver quality, manage risk and achieve regulatory compliance.” It has more than 150 laboratories and 10,000 employees. In relation to PCBs, UL has almost 60 years of experience testing and approving materials to make a board as well as the board itself. This includes electrical and fire safety, and mechanical durability.
Having UL recognition ensures the end customer of a PCB will not have to spend extra time and resources on their own tests while also sending a strong message that your company cares about safety and sustainability. It’s also important to note that processes can affect safety. Simply because all the materials used in PCB production are UL-approved, materials can be influenced by the manufacturing or the design—say if two different materials are combined with one another.
Customers from around the world demand factories that can achieve UL recognition. Having UL recognition is very important for PCB factories to produce secure boards and be able to access the international market. Specifically in China, there are more than 1,200 PCB factories with UL recognition. All NCAB factories, for example, must have UL recognition for any given configuration they are approved to manufacture. This is one of the first steps in sourcing a new factory as a partner. Although it is still important to continuously evaluate this as PCB technology, it increases and changes exponentially. As a new technology emerges, we need to make sure a factory is approved for that material and/or process. Also of note, UL does not mean the quality of the board is certified exclusively. For NCAB Group, it is just one of several factors we implement to determine quality of delivery.
UL recognition can also be required by law when exporting to some countries. The big challenge with UL is that for a PCB factory it is both costly and time consuming to obtain UL recognition for all the base laminates, prepregs, solder masks, and so on, in various combinations of builds. There is a great temptation for PCB factories—even those in the USA and Europe—to take shortcuts with their recognition. The consequences can be disastrous for someone who supplies products without UL recognition or with incorrect marking. In the worst case, they would be forced to do a general product recall from the market—leading to huge costs and perhaps even bankruptcy. As a purchaser and user of PCBs, you risk falling into many traps regarding UL recognition. It is vital to thoroughly check that the factories’ certifications really apply to the products you are buying.
When purchasing PCBs with safety in mind, I recommend always buying from a reputable source, and to inspect the UL marking on PCBs. All boards must be labeled in a specific way, to enable you to track where they were manufactured. UL has an online directory of certifications and a database for PCBs, laminates, and surface materials. When in doubt, contact your trusted PCB supplier. If they are unable to support you in this matter, beware.
Jeffrey Beauchamp is a field application engineer at NCAB Group.