When deciding whether or not to purchase an electronic device, system, or appliance, what is the primary consideration? For many people, color, size, shape, user interface (UI), or some other exterior attribute seals the deal. These are the same people who are likely to get stuck with a great looking car that doesn’t run well. Looking good is not much comfort when your vehicle is sitting in the shop. Of course, you are not one of these folks. Instead, you realize that the most important aspect of a product is how well it is built and what is made of.
Industrial automation in smart factory
For the most part, circuit boards cannot be seen directly when in use; therefore, they are judged on performance, quality of manufacture and materials. In some situations, the failure of poorly built boards may be an annoyance. In other situations, such as when used in industrial systems like smart factory robotics, board failures are much more than headaches. They cut into or offset profitability and can even be the source of damage to other equipment and injury to personnel.
The range of industrial PCBs, boards that are designed and manufactured to operate in production environments, is wide and diverse. As such, there are common attributes, which can be accounted for by following a well-planned checklist to ensure production is industrial-ready, and custom ones that require case-by-case consideration. One such case is industrial boards that contain high voltages. Let’s investigate these boards, including voltage levels that may be present and where they may be used. Then we can put forth a means of ensuring that the high voltage PCB material selected aids in the quality manufacturing of them.
High Voltage Industrial PCBs
Before discussing high voltage industrial boards, let’s define what is meant by high voltage. It may surprise you to know that there is no universally accepted standard or value that everyone agrees is high voltage. Instead it this notation has different meanings based on the system under examination or application. For example, a general consensus can be found to classify voltages above 100V (AC or DC) as high voltage. However, in power systems, this value would be considered low voltage as voltages can be as high kVs on transmission lines and MVs at generation stations. According to the National Electric Code (NEC), which covers the electrical systems and wiring in industrial environments, 100V is the threshold for high voltage.
It is common for factories to require high voltages to run equipment and meet other operational needs, such as lighting. And high voltage boards may be used for the following in industry:
Factory Applications of High Voltage PCBs
🏭 Power supplies
Power supplies and/or converters are used throughout industrial facilities. This is typically to step down voltages for distribution to other circuitry.
🏭 Motor Drives
Assembly lines and other industrial equipment require drives and controllers to maintain speed and control operation. These and other embedded circuit boards are crucial to production, especially for advanced facilities.
Another area where high voltage boards are used is in robotics. This may include integrated automation operations that employ robots and cobots, robots that control other robots.
🏭 Lighting and HVAC
High voltages are also used for common structure functions, such as lighting and HVAC. For advanced or smart factories, these systems may employ PCB controllers.
🏭 Computing Equipment
IIoT facilities rely heavily on computing systems, peripherals and networking that are comprised of high-speed PCBs for data and information transfers, display and analyses. These systems are typically high-performance server stations that are powered from high voltage AC sources like mains.
Now, that we know how high voltage boards are used in industrial environments, let’s see how to ensure that we select the best materials for them.
How to Select High Voltage PCB Material for Industrial Boards
A major contributor to the quality of your industrial board’s manufacture or production is the materials used. However, the overall objective is for your board to operate reliably over its lifetime in what can be a somewhat hazardous environment. And reliability includes functionality or operation and durability. To optimize durability, your material selections for your board’s manufacture should not be limited to the stackup, but include the following:
The Best High Voltage PCB Material Selections for Industrial PCBs
High voltages are usually accompanied by high power, which means high current and temperatures. Therefore, you should select substrate material that has a high coefficient of temperature expansion (CTE) and design for good thermal dissipation and distribution. Otherwise, dielectric breakdown may occur which can affect high voltage signal integrity by altering impedances and trace currents. And if you have a flex design, you also need to consider the number of heating cycles required for manufacturing.
The type or quality of copper used for your board’s surfaces is also a consideration. For example, rough copper improves the peel strength of your laminate, which is better for high currents that typically accompany high voltages. However, higher quality copper means more expensive board materials. Therefore, you need to balance performance with cost.
- Conformal Coating
Conformal coating should definitely be used for industrial PCBs. However, some chemicals perform better for high voltage applications. For example, acrylic-based coatings typically perform well and are not as susceptible to high voltage tracking which will cause dielectric breakdown.
|Tempo‘s Industry 4.0 Custom PCB Manufacturing Services|
Material selection for industrial boards is not limited to the stackup choices. Although these are very important, the other materials listed above play a significant role in the ability of your high voltage boards to function reliably in industrial environments. Tempo Automation, the PCB industry leader in fast, high-quality prototype and low-volume manufacturing is experienced in building boards to meet the requirements of production facilities and will help you meet your objectives.
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 Designer or Cadence Allegro user, you can simply add these files to your PCB design software. For Mentor Pads or other design packages, we furnish DRC information in other CAD formats and Excel.