|

If the PCB is sealed with solid sealant, how to determine the creepage distance and clearance?

functional insulation as well as other insulation exists on circuit boards. Typically, the surface environment of a circuit board is determined to be either Pollution degree 3 or pollution degree 2.
If the circuit board is mounted in an electrical box and sealed with a solid sealant, the sealing will look as follows:

What should be the pollution degree of the functional insulation between the copper tracks on the PCB and between the energized parts on the component?
Here, the functional insulation is located inside the solid sealant and there is no contact between the path of the functional insulation and the outside air. According to the definition of electrical clearance, it can be assumed that there is no electrical clearance here. At the same time, the creepage distance is defined along the surface of the insulation, and obviously, there is no surface here either.
It may be argued that there is still a gap between the solid sealant and the PCB material, and that an clearance and creepage distance can be formed, but it is a pollution degree 1. This view is more conservative, because even if a gap is formed, it is not a continuous gap.
At the same time, the pictures show that this solid state sealant fills so well that it is essentially impossible to create a gap. The manufacturer also indicates that there is a vacuuming procedure prior to filling the solid state sealant. When we evaluate this type of structure, we can have some control over the material and specification of the solid state sealant, as well as some control over the filling process.
There may also be reinforced insulation internally, as there are isolation measures between the 220-240V circuit portion and the SELV circuit, which are judged by the same rules for clearance and creepage distances as functional insulation.

Similar Posts

  • āļ‚āđ‰āļ­ 3 – āļˆāļ°āđ€āļ‚āđ‰āļēāđƒāļˆāļ„āļģāļˆāļģāļāļąāļ”āļ„āļ§āļēāļĄāļ‚āļ­āļ‡ â€œāļ‰āļ™āļ§āļ™āđ€āļŠāļĢāļīāļĄâ€ āđ„āļ”āđ‰āļ­āļĒāđˆāļēāļ‡āđ„āļĢ

    āļ”āļąāļ‡āđāļŠāļ”āļ‡āđƒāļ™āļĢāļđāļ›āļ”āđ‰āļēāļ™āļĨāđˆāļēāļ‡ āļˆāļēāļāļžāļ·āđ‰āļ™āļœāļīāļ§āļ”āđ‰āļēāļ™āļ™āļ­āļāļ‚āļ­āļ‡āļ‰āļ™āļ§āļ™āļžāļ·āđ‰āļ™āļāļēāļ™ (āđƒāļ™āļ—āļĩāđˆāļ™āļĩāđ‰āļŠāļēāļĄāļēāļĢāļ–āđ€āļ‚āđ‰āļēāđƒāļˆāđ„āļ”āđ‰āļ§āđˆāļēāđ€āļ›āđ‡āļ™āļžāļ·āđ‰āļ™āļœāļīāļ§āļ”āđ‰āļēāļ™āļ™āļ­āļāļ‚āļ­āļ‡āļ›āļĨāļ­āļāļĨāļ§āļ”āļ‚āļ­āļ‡āļĨāļ§āļ”āļ āļēāļĒāđƒāļ™ āļŦāļĢāļ·āļ­āļžāļ·āđ‰āļ™āļœāļīāļ§āļ§āļąāļŠāļ”āļļāļžāļĨāļēāļŠāļ•āļīāļāļ‚āļ­āļ‡āļŠāļ§āļīāļ•āļŠāđŒ) āđ„āļ›āļĒāļąāļ‡āļ•āļģāđāļŦāļ™āđˆāļ‡āļ—āļĩāđˆāļŠāļēāļĄāļēāļĢāļ–āļ—āļģāđ„āļ”āđ‰ āļˆāļēāļāļ āļēāļžāļ•āļąāļ§āļ­āļĒāđˆāļēāļ‡āļ—āļĩāđˆāļœāļđāđ‰āđƒāļŠāđ‰āļŠāļąāļĄāļœāļąāļŠ (āļāļēāļ„āļĢāļ­āļšāļ”āđ‰āļēāļ™āļĨāđˆāļēāļ‡āļŦāļĢāļ·āļ­āļ”āđ‰āļēāļ™āļ‚āđ‰āļēāļ‡āļ‚āļ­āļ‡āđ€āļ„āļĢāļ·āđˆāļ­āļ‡āđƒāļŠāđ‰āđ„āļŸāļŸāđ‰āļē) āļŠāļēāļĄāļēāļĢāļ–āļžāļīāļˆāļēāļĢāļ“āļēāļ§āđˆāļēāļāļēāļ„āļĢāļ­āļšāļ”āđ‰āļēāļ™āļĨāđˆāļēāļ‡āđāļĨāļ°āļ”āđ‰āļēāļ™āļ‚āđ‰āļēāļ‡āļ‚āļ­āļ‡āđ€āļ„āļĢāļ·āđˆāļ­āļ‡āđƒāļŠāđ‰āđ„āļŸāļŸāđ‰āļēāđ€āļ›āđ‡āļ™āļ‰āļ™āļ§āļ™āđ€āļŠāļĢāļīāļĄāđ„āļ”āđ‰ āđƒāļ™āļ—āļģāļ™āļ­āļ‡āđ€āļ”āļĩāļĒāļ§āļāļąāļ™ āļĢāļ°āļĒāļ°āļŦāđˆāļēāļ‡āļ•āļēāļĄāļœāļīāļ§āļ‰āļ™āļ§āļ™āļˆāļēāļāļ›āļĨāļ­āļāļĨāļ§āļ”āļ•āļ°āļāļąāđˆāļ§āļ āļēāļĒāđƒāļ™āļ•āļēāļĄāļžāļ·āđ‰āļ™āļœāļīāļ§āļ”āđ‰āļēāļ™āđƒāļ™āļ‚āļ­āļ‡āđ€āļ›āļĨāļ·āļ­āļāļ”āđ‰āļēāļ™āļ‚āđ‰āļēāļ‡āđ„āļ›āļĒāļąāļ‡āļ•āļģāđāļŦāļ™āđˆāļ‡āļ—āļĩāđˆāļœāļđāđ‰āđƒāļŠāđ‰āļ āļēāļĒāļ™āļ­āļāļŠāļąāļĄāļœāļąāļŠāđ„āļ”āđ‰āļŠāļēāļĄāļēāļĢāļ–āļāļģāļŦāļ™āļ”āđ€āļ›āđ‡āļ™āļ‰āļ™āļ§āļ™āđ€āļŠāļĢāļīāļĄāđ„āļ”āđ‰ āļˆāļēāļāļ™āļąāđ‰āļ™āđ€āļ›āđ‡āļ™āļĢāļ°āļĒāļ°āļ—āļēāļ‡āđ€āļŠāđ‰āļ™āļ•āļĢāļ‡āļ—āļĩāđˆāļŠāļąāđ‰āļ™āļ—āļĩāđˆāļŠāļļāļ”āļˆāļēāļāļ‰āļ™āļ§āļ™āļžāļ·āđ‰āļ™āļāļēāļ™āļ āļēāļĒāđƒāļ™ āļœāđˆāļēāļ™āļ­āļēāļāļēāļĻāđ„āļ›āļĒāļąāļ‡āļŠāļ–āļēāļ™āļ—āļĩāđˆāļ—āļĩāđˆāļœāļđāđ‰āđƒāļŠāđ‰āļ āļēāļĒāļ™āļ­āļāļŠāļēāļĄāļēāļĢāļ–āļŠāļąāļĄāļœāļąāļŠāđ„āļ”āđ‰āļŠāļēāļĄāļēāļĢāļ–āļāļģāļŦāļ™āļ”āđ€āļ›āđ‡āļ™āļĢāļ°āļĒāļ°āļŦāđˆāļēāļ‡āļ‚āļ­āļ‡āļ‰āļ™āļ§āļ™āđ€āļŠāļĢāļīāļĄāđ„āļ”āđ‰ āļĢāļ°āļĒāļ°āļŦāđˆāļēāļ‡āđ‚āļ”āļĒāļ—āļąāđˆāļ§āđ„āļ›āļŦāļĄāļēāļĒāļ–āļķāļ‡āļŠāđˆāļ­āļ‡āļ§āđˆāļēāļ‡āļĢāļ°āļŦāļ§āđˆāļēāļ‡āđ€āļ›āļĨāļ·āļ­āļāļ”āđ‰āļēāļ™āļĨāđˆāļēāļ‡āđāļĨāļ°āđ€āļ›āļĨāļ·āļ­āļāļ”āđ‰āļēāļ™āļ‚āđ‰āļēāļ‡ An insulation that is outside the basic insulation and is independent of the basic insulation, and is usually accessible to the user. supplementary insulation, as the name implies, is additional, and refers to insulation added to the basic insulation. This involves a…

  • Clause 3 – How to understand the definition of “combined appliance”

    combined appliance: appliance incorporating heating elements and motors. We know that this standard mainly protects against the following five types of dangers, which are electric shock, mechanical damage from moving parts, thermal damage (such as burns), fire damage, chemical and biological damage. Generally speaking, thermal damage is caused by electric heating elements, and mechanical damage…

  • |

    Clause 3 – How to understand the definition of “room temperature”

    room temperature: ambient temperature specified in the general conditions for the tests.Note 1 to entry: The ambient temperature is specified in 5.7. This item comes from standard IEC 60335-1:2020 edition 6.0. In commented version (CMV) of the official standard IEC 60335-1:2020 edition 6.0 allows the user to identify the changes made to the previous edition…

  • Clause 3 – How to Understand the Definition of “all-pole disconnection”

    all-pole disconnection: disconnection of both supply conductors by a single initiating action or, for multi-phase appliances, disconnection of all supply conductors by a single initiating actionNOTE For multi-phase appliances, the neutral conductor is not considered to be a supply conductor. Single-phase power: An AC power system composed of one live wire and one neutral wire.​Three-phase…

  • āļ‚āđ‰āļ­ 3 – āļ§āļīāļ˜āļĩāļ—āļģāļ„āļ§āļēāļĄāđ€āļ‚āđ‰āļēāđƒāļˆāļ„āļģāļˆāļģāļāļąāļ”āļ„āļ§āļēāļĄāļ‚āļ­āļ‡ “āļŦāļĄāđ‰āļ­āđāļ›āļĨāļ‡āđāļĒāļāļ„āļ§āļēāļĄāļ›āļĨāļ­āļ”āļ āļąāļĒ”

    āļŦāļĄāđ‰āļ­āđāļ›āļĨāļ‡āļ—āļĩāđˆāļāļĨāđˆāļēāļ§āļ–āļķāļ‡āđƒāļ™āļ—āļĩāđˆāļ™āļĩāđ‰āđƒāļŠāđ‰āđ€āļžāļ·āđˆāļ­āļˆāđˆāļēāļĒāđ„āļŸāđƒāļŦāđ‰āļāļąāļšāđ€āļ„āļĢāļ·āđˆāļ­āļ‡āđƒāļŠāđ‰āđ„āļŸāļŸāđ‰āļēāļŦāļĢāļ·āļ­āļ§āļ‡āļˆāļĢ āļŦāļĄāđ‰āļ­āđāļ›āļĨāļ‡āļ—āļąāđˆāļ§āđ„āļ›āļŠāđˆāļ§āļ™āđƒāļŦāļāđˆāļˆāļ°āļˆāđˆāļēāļĒāđ„āļŸāđƒāļŦāđ‰āļāļąāļšāļ§āļ‡āļˆāļĢ āđāļĨāļ°āļˆāđˆāļēāļĒāđ„āļŸāđƒāļŦāđ‰āļāļąāļšāđ€āļ„āļĢāļ·āđˆāļ­āļ‡āđƒāļŠāđ‰āđ„āļŸāļŸāđ‰āļēāļšāļēāļ‡āļŠāđˆāļ§āļ™ āļŠāļīāđˆāļ‡āļŠāļģāļ„āļąāļāļ—āļĩāđˆāļ™āļĩāđˆāļ„āļ·āļ­āļāļēāļĢāļ§āļąāļ”āļāļēāļĢāđāļĒāļāļĢāļ°āļŦāļ§āđˆāļēāļ‡āļ‚āļ”āļĨāļ§āļ”āļ­āļīāļ™āļžāļļāļ•āđāļĨāļ°āļ‚āļ”āļĨāļ§āļ”āđ€āļ­āļēāļ•āđŒāļžāļļāļ• āļ‹āļķāđˆāļ‡āļ•āđ‰āļ­āļ‡āđ€āļ›āđ‡āļ™āļ‰āļ™āļ§āļ™āļŠāļ­āļ‡āļŠāļąāđ‰āļ™āļŦāļĢāļ·āļ­āļ‰āļ™āļ§āļ™āđ€āļŠāļĢāļīāļĄāđāļĢāļ‡ āļŦāļĢāļ·āļ­āļ‰āļ™āļ§āļ™āļŠāļ™āļīāļ”āđ€āļ—āļĩāļĒāļšāđ€āļ—āđˆāļē āļ‚āđ‰āļ­āļāļģāļŦāļ™āļ”āļ™āļĩāđ‰āļ„āļ·āļ­āđ€āļžāļ·āđˆāļ­āđƒāļŦāđ‰āđāļ™āđˆāđƒāļˆāļ§āđˆāļēāļ‚āļ”āļĨāļ§āļ”āļ›āļāļĄāļ āļđāļĄāļīāđāļĨāļ°āļ‚āļ”āļĨāļ§āļ”āļ—āļļāļ•āļīāļĒāļ āļđāļĄāļīāļĄāļĩāļ‰āļ™āļ§āļ™āđ€āļžāļĩāļĒāļ‡āļžāļ­ āļŦāļēāļāļ‰āļ™āļ§āļ™āđ€āļžāļĩāļĒāļ‡āļžāļ­ āļāļēāļĢāđāļĒāļāļĢāļ°āļŦāļ§āđˆāļēāļ‡āļ‚āļ”āļĨāļ§āļ”āļ›āļāļĄāļ āļđāļĄāļīāđāļĨāļ°āļ‚āļ”āļĨāļ§āļ”āļ—āļļāļ•āļīāļĒāļ āļđāļĄāļīāļ‚āļ­āļ‡āļŦāļĄāđ‰āļ­āđāļ›āļĨāļ‡āđ„āļŸāļŸāđ‰āļēāļˆāļ°āļ„āđˆāļ­āļ™āļ‚āđ‰āļēāļ‡āļ›āļĨāļ­āļ”āļ āļąāļĒ āļ‚āđ‰āļ­āļ„āļ§āļĢāļĢāļ°āļ§āļąāļ‡āđƒāļ™āļāļēāļĢāļ›āđ‰āļ­āļ‡āļāļąāļ™āļŠāļ­āļ‡āļŠāļąāđ‰āļ™ āļŦāļĄāđ‰āļ­āđāļ›āļĨāļ‡āđ„āļŸāļŸāđ‰āļēāļ—āļĩāđˆāđƒāļŠāđ‰āļāļąāļ™āļĄāļēāļāļ—āļĩāđˆāļŠāļļāļ”āļŠāļ­āļ‡āļ•āļąāļ§āđƒāļ™āđ€āļ„āļĢāļ·āđˆāļ­āļ‡āđƒāļŠāđ‰āđƒāļ™āļ„āļĢāļąāļ§āđ€āļĢāļ·āļ­āļ™āđāļŠāļ”āļ‡āđƒāļ™āļĢāļđāļ›āļ”āđ‰āļēāļ™āļĨāđˆāļēāļ‡ āļŦāļĄāđ‰āļ­āđāļ›āļĨāļ‡āļŠāļ™āļīāļ”āđāļĢāļāļ—āļĩāđˆāđƒāļŠāđ‰āđƒāļ™āļšāļ­āļĢāđŒāļ” PCBboard āļ‚āļ­āļ‡āļŠāļ§āļīāļ•āļŠāđŒāđ„āļŸ āļŦāļĄāđ‰āļ­āđāļ›āļĨāļ‡āļŠāļ™āļīāļ”āļ™āļĩāđ‰āļˆāļ°āļ§āļēāļ‡āļ‚āļ”āļĨāļ§āļ”āļ›āļāļĄāļ āļđāļĄāļīāđāļĨāļ°āļ‚āļ”āļĨāļ§āļ”āļ—āļļāļ•āļīāļĒāļ āļđāļĄāļīāļ—āļąāļšāļšāļ™āđāļāļ™āđāļĄāđˆāđ€āļŦāļĨāđ‡āļāđ€āļ”āļĩāļĒāļ§āļāļąāļ™ āļ”āļąāļ‡āļ™āļąāđ‰āļ™ āđ€āļžāļ·āđˆāļ­āđƒāļŦāđ‰āđāļ™āđˆāđƒāļˆāļ§āđˆāļēāļĢāļ°āļĒāļ°āļŦāđˆāļēāļ‡āļ•āļēāļĄāļœāļīāļ§āļ‰āļ™āļ§āļ™āđāļĨāļ°āļĢāļ°āļĒāļ°āļŦāđˆāļēāļ‡āļ—āļēāļ‡āđ„āļŸāļŸāđ‰āļēāļĢāļ°āļŦāļ§āđˆāļēāļ‡āļ›āļāļĄāļ āļđāļĄāļīāđāļĨāļ°āļ—āļļāļ•āļīāļĒāļ āļđāļĄāļī āļˆāļķāļ‡āđ„āļĄāđˆāļŠāļēāļĄāļēāļĢāļ–āļ§āļēāļ‡āļ‚āļ”āļĨāļ§āļ”āļ—āļĩāđˆāļžāļąāļ™āđ„āļ§āđ‰āļšāļ™āđƒāļšāļŦāļ™āđ‰āļēāļŠāđˆāļ§āļ™āļšāļ™āđāļĨāļ°āļŠāđˆāļ§āļ™āļĨāđˆāļēāļ‡āđ„āļ”āđ‰ āļ‚āļ”āļĨāļ§āļ”āļˆāļ°āļ•āđ‰āļ­āļ‡āļ­āļĒāļđāđˆāļŦāđˆāļēāļ‡āļˆāļēāļāļœāļīāļ§āļŦāļ™āđ‰āļēāļ”āđ‰āļēāļ™āļšāļ™āđāļĨāļ°āļ”āđ‰āļēāļ™āļĨāđˆāļēāļ‡ āļ”āļąāļ‡āđāļŠāļ”āļ‡āđƒāļ™āļĢāļđāļ›āļ”āđ‰āļēāļ™āļĨāđˆāļēāļ‡: āđ€āļžāļ·āđˆāļ­āļŠāđˆāļ§āļĒāđƒāļŦāđ‰āļœāļđāđ‰āļ­āđˆāļēāļ™āđ€āļ‚āđ‰āļēāđƒāļˆāđ‚āļ„āļĢāļ‡āļŠāļĢāđ‰āļēāļ‡āļ‚āļ­āļ‡āļŦāļĄāđ‰āļ­āđāļ›āļĨāļ‡āļ™āļĩāđ‰āđ„āļ”āđ‰āļ”āļĩāļ‚āļķāđ‰āļ™ āļœāļĄāļˆāļķāļ‡āđ„āļ”āđ‰āļ™āļģāļĢāļđāļ›āļ–āđˆāļēāļĒāļ āļēāļĒāļ™āļ­āļāđāļĨāļ°āļ āļēāļĒāđƒāļ™āļ‚āļ­āļ‡āļŦāļĄāđ‰āļ­āđāļ›āļĨāļ‡āļ—āļąāđ‰āļ‡āļŦāļĄāļ”āļĄāļēāđ„āļ§āđ‰āđƒāļ™āļŦāļ™āđ‰āļēāļ™āļĩāđ‰āđ€āļžāļ·āđˆāļ­āđƒāļŠāđ‰āļ­āđ‰āļēāļ‡āļ­āļīāļ‡āļŠāļģāļŦāļĢāļąāļšāļœāļđāđ‰āļ­āđˆāļēāļ™ āļĄāļļāļĄāļĄāļ­āļ‡āđ‚āļ”āļĒāļĢāļ§āļĄāļŠāļģāļŦāļĢāļąāļšāļŦāļĄāđ‰āļ­āđāļ›āļĨāļ‡āļ‰āļ™āļ§āļ™āļ™āļīāļĢāļ āļąāļĒ The other is a drawer-type linear transformer, as shown below: