0603 Metric Imperial Confusion - Page 1
Forum section: electronics / projects

author: Pentoad
author_rank: Regular Contributor
timestamp: October 31, 2019, 07:42:16 pm
content: Hello everyone, having a bit of confusion here.I'm now ready to order some resistors and realised that there's a metric and imperial 0603 size. I don't know whether the resistors I have placed in my design are metric or imperial.This is what they look like, the grid is 1mm.

author: MagicSmoker
author_rank: Super Contributor
timestamp: October 31, 2019, 07:51:13 pm
content: Center-to-center distance for Imperial 0603 is 1.6mm; yours looks like metric 0603. EDIT - err, maybe not. You just use much larger pads than I do.The fact that there is both an Imperial and a metric 0603 in the first place is a rant all to itself.

author: jmw
author_rank: Frequent Contributor
timestamp: October 31, 2019, 07:51:27 pm
content: 0603 = metric 1608 (1.6 x .8 mm). The distance between center of pads looks like around 1.5 mm so that's got to be an imperial 0603. Metric 0603 is 0201 - that's tiny! The part would fit on one of those pads with room to spare.

author: NivagSwerdna
author_rank: Super Contributor
timestamp: October 31, 2019, 08:05:19 pm
content: Whenever I get confused... I remember that I used to use 0805 and now I use 0603... and then I checkhttps://en.wikipedia.org/wiki/File:SMT_sizes,_based_on_original_by_Zureks.svgand conclude that even though it is the year 2019... it is likely to be imperial.If you measure it... and compare...http://www.resistorguide.com/resistor-sizes-and-packages/As expected imperial.And when I search Farnell for "0603 smd 1k" you end up finding.. "SMD Chip Resistor, 0603 [1608 Metric]" so for all intents and purposes it's probably worth only thinking in imperial sizes...I wonder if there are people who think in metric?

author: Pentoad
author_rank: Regular Contributor
timestamp: October 31, 2019, 08:51:41 pm
content: I use metric for nearly everything but in this case I had no idea what standard the component footprint was using as easyeda never specified. It makes sense now though, resistors ordered.

author: bson
author_rank: Unknown
timestamp: October 31, 2019, 08:56:36 pm
content: I'd use imperial sizes down to 0201, then switch to metric and make sure to qualify it as such. As far as I can tell this matches equipment manufacturers as well, at least based on what I've seen at Semicon West.

author: I wanted a rude username
author_rank: Frequent Contributor
timestamp: October 31, 2019, 09:56:07 pm
content: Quote from: NivagSwerdna on October 31, 2019, 08:05:19 pmI do (along with the rest of the PCB design unless doing pure through-hole for fun), and it's liberating. The metric sizes precisely encode the device size ... noconversion tablesrequired. But when ordering passives, searching is more effective in imperial.

author: Lunasix
author_rank: Regular Contributor
timestamp: October 31, 2019, 10:05:21 pm
content: Some years ago, I ordered capacitors in 0603 size, but didn't seen it was 0603 metric (didn't know...) and received 0603 metric, which means 0201 imperial. Very small ! I always have these capacitors, and will never use them !Now, before ordering, I verify the unity.

author: I wanted a rude username
author_rank: Frequent Contributor
timestamp: October 31, 2019, 10:30:52 pm
content: Challenge yourself.0603 soldered onto pads designed for 1608 (imperial 0603):

author: Gribo
author_rank: Frequent Contributor
timestamp: November 01, 2019, 07:50:57 pm
content: Meh, try Imperial 0402 and metric 0402 for a challenge.