Package Dimensions of Components

[hw01.jt]

hello everyone ,
 In IPC STANDARDS WHAT IS THE CONVERSION CRITERIA FOR CONVERTING COMPONENTS DIMENSION in mm to inch for ex.when i selecting component package of 3528 mm and when i trying to get in inch then the actual problem arises ....if i convert  35 mm *28 mm into inch then i get 1.377*1.10, so is there any rounding system in dimension ? and if yes then how many decimal places ? because there are both type of packages are available in market like 1311 and 1411 .

so i hope you will able to clear my doubt . 

[Siwastaja]

Hard to understand what you are after.

There are no special conversion factors. 1 inch = 25.4mm and that's it. Don't do unnecessary rounding. If you round, round an order of magnitude below your PCB manufacturing / placement accuracy so that it doesn't matter.

3528mm or 3.528 meters is quite a heck of a component dimension! I guess you need several people to pick/place it.

If you are thinking about magic number sequences in package names, they are just that, names, nothing else. You always look at the actual drawings for dimensions, from the actual manufacturer. You can't work on an assumption that a package name number sequence that resembles the dimensions would actually contain any exact or useful dimensions of the part.

[T3sl4co1l]

Who needs inches in India? (Contracting to US?)

But yes... units are just that, units, a multiplier, nothing more.  1 inch is defined as exactly 25.4mm (the US is technically metric, customary units just have a different multiplier on them because...reasons).

Conversion is trivial with various tools: https://www.google.com/search?q=3528mm+in+inches&oq=3528mm+in+inches

Tim

[apurvdate]

3528mm or 3.528 meters is quite a heck of a component dimension! I guess you need several people to pick/place it.

LOL.. i think he means if package in metric 3225 what is its equivalent in imperial.. which will be 1210
its not 3528 mm.. it should be 3.5mm x 2.8mm

hello everyone ,
 In IPC STANDARDS WHAT IS THE CONVERSION CRITERIA FOR CONVERTING COMPONENTS DIMENSION in mm to inch for ex.when i selecting component package of 3528 mm and when i trying to get in inch then the actual problem arises ....if i convert  35 mm *28 mm into inch then i get 1.377*1.10, so is there any rounding system in dimension ? and if yes then how many decimal places ? because there are both type of packages are available in market like 1311 and 1411 .

so i hope you will able to clear my doubt . 

http://www.resistorguide.com/resistor-sizes-and-packages/
this page may help you understanding conversion.. but personally i havn't seen/used 3528 package..

edit: even i missed some decimal points