A couple old metrology equipment dated back from the 80s I still use calls them ‘mil’. It’s got dual dials for mil/mm. Gets me confused sometimes because the gauge can go down to couple millionths of an inch/couple 10s of nanometers.
In the design and manufacture of PCBs (aka circuit boards) a “mil” is a one thousandth of an inch, so it makes sense that’s what is being used in this context.
Also the maths check out: 0.005 inches is equal to aprox 0.12mm, “just over 0.1mm”.
Yeah, I found it wierd too when I started designing PCBs (as hobby) that “mill” actually stood for thousanth of an inch.
Probably for historical reasons, there are tons of things in the older domains within electronics that are based on inches rather than metric units: for example the spacing between the legs of a microchip in the older chip package formats (so called DIP, the ones with legs that go into holes) is exactly 0.1"
The sizes in more modern electronics isn’t usually based on inches anymore, but circuit boards are old tech (even if done with new materials) so there are still a number of measures in there which are based on inches.
What is a mil in this context? I’m genuinely curious.
Probably one thousandth of an inch.
Ew.
Yes.
Hey thousands of an inch are the only part of our imperial system that actually makes sense
I’ve heard it referred to as ‘thou’ but not ‘mil’
A couple old metrology equipment dated back from the 80s I still use calls them ‘mil’. It’s got dual dials for mil/mm. Gets me confused sometimes because the gauge can go down to couple millionths of an inch/couple 10s of nanometers.
LVDT for those curious.
Correct.
A millimeter i.e a thousands of a meter.
edit: I was wrong, confusingly enough it is a thousands of an inch
5 mm isn’t ‘just over 0.1 mm’. That can’t be right.
Well, it depends on your margin of error.
In the design and manufacture of PCBs (aka circuit boards) a “mil” is a one thousandth of an inch, so it makes sense that’s what is being used in this context.
Also the maths check out: 0.005 inches is equal to aprox 0.12mm, “just over 0.1mm”.
I stand corrected, and I see I didn’t read the comment thoroughly enough either.
Colloquially as a non-pcb maker I would use and hear the term “mill” as short form millimeter so I assumed it was that.
so TIL :)
Yeah, I found it wierd too when I started designing PCBs (as hobby) that “mill” actually stood for thousanth of an inch.
Probably for historical reasons, there are tons of things in the older domains within electronics that are based on inches rather than metric units: for example the spacing between the legs of a microchip in the older chip package formats (so called DIP, the ones with legs that go into holes) is exactly 0.1"
The sizes in more modern electronics isn’t usually based on inches anymore, but circuit boards are old tech (even if done with new materials) so there are still a number of measures in there which are based on inches.