High Voltage PCB Design Tips | Forum

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xysoom
xysoom Dec 20 '20
Along with designing electrical hardware and running for stress management, I’m an avid knitter. My grandmother taught me when I was in grade school, and I’ve taught a dozen or so people along the way. Before you can get to the fun part of actually knitting something, you have to select a yarn. Is it for a newborn? Then I want it to be soft, but also machine washable so the mom can actually use it without worrying about handwashing. Does it matter if it’s itchy? What if someone is allergic to wool? Does it need to drape or hold its shape?To get more news about BT PCB, you can visit pcbmake official website.
I have to sort through a surprising number of parameters before I can start knitting, or I’ll have to scrap everything and start fresh when it doesn’t turn out well. The same is true when you select the materials for a PCB. Early in your PCB design career, you probably didn’t specify much, and unless it was for a specialized project, it probably turned out fine. However, once you level up to high voltage or other niche PCB applications, you need to start taking additional design requirements into consideration.
SELECT AN APPROPRIATE PCB MATERIAL
The foundation of your PCB is the board, so that’s the first material specification you should consider. You want the material to be appropriate for the performance requirements, but also for the operating environment since that will have a large impact on how the PCB material ages.
For a high voltage PCB, you’ll need a board material that’s specifically designed to tolerate an overvoltage event, as well as the regular high V operating conditions. There are a few material options you to consider:
FR4 Laminate: FR4 high a very high dielectric breakdown. However, it is more porous than BT epoxy and polyimide, which makes it easier for the board to become contaminated. It also has a weak edge structure, and as the edge cracks, the dielectric value will decrease. Aging is a likely problem, especially for electronics near the edge. FR4 also has no recovery or protection from carbonization that occurs during overvoltage events.
BT Epoxy: A thermoset resin, BT epoxy has strong sidewalls and is better for applications with planar coils and medium voltage circuits.
Isola, high V laminates: There are several high voltage laminates, Isola is one of the most well known, that actually extinguish arcs and leave a non-conductive base layer. While that is an incredible performance advantage in high V applications, understand the design restrictions before you start. These laminates are usually quite pricey, and you can only produce single sided boards or very simple two sided boards.
When you first start discussing production, get the datasheets for all your options from the manufacturer and make sure the performance matches your requirements. Also, don’t mix and match the insulators on your board. The mismatch in material properties can cause issues in manufacturing and performance down the line.
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