smallest feature on stanard PCB? - Page 1
Forum section: electronics / general

author: pcm81
author_rank: Regular Contributor
timestamp: September 26, 2025, 01:59:07 am
content: I realize you can etch a picture of sonic that is few thousand atoms in size, but that is not what i am asking about.For simple components like resistors there are standards like 0603, 0402 etc with smallest being 01005 as far as i know. But for ICs i do not know all the standards. What i am trying to figure out is the size of the smallest functional feature that can be on a pcb like a trace or a pad. Basically i am learning about PCB level repair and want to figure out where on the scale of all things possible the current dimension of what i am messing with lies. So far the smallest thing i did was solder a 0.1mm wire and repaired a 0.25mm pad. I realize that if we go down the rabbit hole of grinding through the packaging inside a chip than we're talking nanometer scale; i am not interested in that deep of a rabbit hole, just the pcb level like via, pads, traces.

author: ataradov
author_rank: Super Contributor
timestamp: September 26, 2025, 02:57:45 am
content: 3mil (0.0762 mm) trace is the minimal "standard" thing you can manufacture on standard FR-4 material. More exotic materials may allow smaller features, but you are not likely to see them in practice.

author: thm_w
author_rank: Super Contributor
timestamp: September 26, 2025, 08:14:06 pm
content: On the lower end of common devices you can look at BGA pad size for an iphone for example, might be 0.1mmhttps://www.diyfixtool.com/products/wl-0-1mm-nand-bga-reballing-stencils-template-for-iphone-a10-a9-a8-cpuBut a lot of stuff will be larger than that, 0.3 to 0.8mm

author: David Hess
author_rank: Super Contributor
timestamp: September 27, 2025, 12:48:29 am
content: Quote from: ataradov on September 26, 2025, 02:57:45 amI have always done layout assuming a 4 mil minimum feature size.As I recall, a 4 mil feature size allows for a single trace under an 0805 part, and 2 traces under a 1206?

author: Smokey
author_rank: Super Contributor
timestamp: September 27, 2025, 01:46:45 am
content: https://www.pcbway.com/capabilities.htmlYou really don't want to exceed their "normal" capabilities or the prices go up pretty fast.

author: pcm81
author_rank: Regular Contributor
timestamp: September 27, 2025, 02:14:20 pm
content: Quote from: Smokey on September 27, 2025, 01:46:45 amI am not interested in making pcbs, i am learning pcb repair and am interested in what is the smallest thing i am going to find, including on crazy specialized boards like from apple... Sounds like 0.1mm is the smallest feature size i will encounter? By feature i mean, pad, trace etc... something i might have to replace or solder to.

author: Smokey
author_rank: Super Contributor
timestamp: September 27, 2025, 08:49:53 pm
content: What I'm saying is that most people who ARE pcb designers will be using mostly the "standard spec". So most boards will fall in that category.Look at the crazy spec of that page to see what the smallest things they can do is. They are a good manufacturer so expect that to be near the limits.

author: nctnico
author_rank: Super Contributor
timestamp: September 28, 2025, 08:14:38 pm
content: Quote from: David Hess on September 27, 2025, 12:48:29 amIME you can't put it like that. PCB manufacturers (like Eurocircuits to name an example which has a clear overview of classifications online) have various classes where it comes to etching precission (width / distance) and drill sizes. I'd say 90um is the smallest you can do and still have a wide choice of PCB manufacturers. But it will be a bit of a special order. For relatively simple layouts I use 125um width/distance as this is compatible with most pooling services and thus a cheap option with little chances of failure. I have seen eval board layouts which use like 60um width/40um distance but you'll have a hard time finding a PCB manufacturer willing to produce such boards in smaller (hundreds) quantities.

author: Smokey
author_rank: Super Contributor
timestamp: September 29, 2025, 01:58:43 am
content: Quote from: David Hess on September 27, 2025, 12:48:29 amYou can fit a 6 mil trace between the pads of an 0402 with 6/6 rules with just a little tweak to the recommendation 0402 footprint.

author: Doctorandus_P
author_rank: Super Contributor
timestamp: September 29, 2025, 07:38:43 am
content: The smallest I know are 01005 (metric) packages for passives, but the wikipedia page below is not really clear.https://en.wikipedia.org/wiki/Surface-mount_technology#Imperial_SMD_packagesThe video below lists some down to 01005 (in banana units) and those are already pretty small. 01005 metric mostly disappears in the grooves of your finger printsOut of curiosity I put my finger under a microscope and I counted 20 ridges in 10mm. So that's an easy to remember 50 micron for each ridge. And thus, you can put 10 of the 01005 metric parts in between two ridges on a finger print.And in addition, you can also start an argument about what a "stanard pcb" is. Cost of the PCB's and the manufacturing get higher with these fine resolutions, and I assume these small parts are only used when there is a good reason to do so.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: September 29, 2025, 08:23:54 am
content: The finest detail is also dependent on the copper weight.Don't take what Apple as a measure of what is accessible to us "mere mortals" - they can spend whatever it takes, and have volumes so high that suppliers will do whatever development is needed to get their business.