How to Measure Creepage Distance

[bjt17]

How to Measure Creepage Distance in MOSFET TO-220 and TO -92 Package or for the high voltage part .

[FvM]

There are several creepage paths involved with TO220, e.g. pin-to-pin, at the case and at the PCB, heatsink to tab, etc.

Can you ask more specific?

[bjt17]

please tell mi how to measure creepage distance in pin-to-pin and heatsink to tab

[FvM]

pin-to-pin seems pretty easy, use a ruler or measure in 3D-model

Find some consideration about heatsink creepage in Infineon AN2012-10 https://www.infineon.com/dgdl/Infine...3d20e0cbf017fe

[Easy peasy]

creepage to earth is usually from the tab to the nearest earthed metal, input to output is as it says, creepage can be from the pins ( any pin ) to earth or output as is the case required ...

working creepage is for the normal max internal ckt, safety creepage is different, usually at least 5mm in to out ( 230Vac ) and 3.2mm to earth

[bjt17]

thanks for replay. i know above mention points. but how to measure in layout design in altium or allegro or any other design software

[marce]

Software can only give you clearance distance (smallest separation between two copper objects). As creepage is the distance over surfaces, it is not always as easy to calculate, so no easy way to measure it... I tend to draw a polyline and use the length of that if the surface is flat, this suffices for most PCB's.
Creepage is always greater than clearance so either leave enough gap to satisfy the creepage requirements, where this is not possible (between connector pins) you can add a slot 1mm or wider to increase the creepage distance.

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creepage to earth is usually from the tab to the nearest earthed metal, input to output is as it says, creepage can be from the pins ( any pin ) to earth or output as is the case required ...

working creepage is for the normal max internal ckt, safety creepage is different, usually at least 5mm in to out ( 230Vac ) and 3.2mm to earth

Creepage is creepage and is dependant on the specification you are working to, there is no working creepage... and don't quote figures, again creepage depends on the envoironment the PCB is going to be subjected to, as creepage is a tracking voltage, surface pollutants come into play, you are quoting clearance distances.