2oz copper, Excessive etching from PCB house - Page 1
Forum section: electronics / general

author: Vertamps
author_rank: Contributor
timestamp: February 24, 2025, 09:48:14 pm
content: Our board house sent us excessively etched PCB's with unusable pads, *two times in a row. I told them to send us a photo before you ship them. I asked if 2oz is doable for fine pitch pads/parts. 1oz copper always works for these 8mil wide pads. Were trying to get more heat out of our chips on this board. Whats your issue/experience if any with 2oz copper?

author: thm_w
author_rank: Super Contributor
timestamp: February 24, 2025, 11:57:28 pm
content: Almost looks more than 2oz, did you measure with calipers? 0.07mm.Here is a site spec 6mil trace:https://docs.oshpark.com/services/two-layer-hhdc/If the pads are 8mil then the traces must be what, 5mil or so?Still should be doable from a competent manufacturer.

author: wraper
author_rank: Unknown
timestamp: February 25, 2025, 12:14:03 am
content: If you need heat dissipation, often doing more layers is better and cheaper than increasing copper thickness. Although 2oz is not something extraordinary, and traces are not too narrow either. As thm_w said, it looks like there is way too much copper depth for 2oz, maybe it's an optical illusion but it looks more like 6-8 oz. I'd peel some trace off and measure actual thickness.

author: Vertamps
author_rank: Contributor
timestamp: February 25, 2025, 02:49:51 pm
content: The copper thickness is just about 0.07mm/2.8mil. I did not rip a trace up, the blank panel edges were 0.67mm, the boards were 0.81mm thick > divide the difference. The pads and traces are 8mil, so extreme etching on the whole board. We can always try another board house, Ideas PCB is expensive anyways. Its odd after receiving emails that the boards would be corrected that they shipped the same quality. Wonder if there drop shipping this from another board house. Most of the other boards are all pretty good over the years. I use JLC pcb for prototypes, i will say that there via holes are more accurate than IdeasPCB. Thank you for your input, im working with our board house. JLC is so cheap i might try them. -William

author: thm_w
author_rank: Super Contributor
timestamp: February 25, 2025, 09:49:51 pm
content: According to this page JLC requires 0.2mm space:https://forum.kicad.info/t/minimum-clearance-violation-with-jlcpcb-discrepancy-between-original-and-production-gerber/42782/6https://forum.kicad.info/t/design-rules-for-jlcpcb/46087/3So you can give it a shot.

author: Rat_Patrol
author_rank: Frequent Contributor
timestamp: February 26, 2025, 04:41:01 am
content: We've done 2 oz copper from JLC many times, never an issue

author: meshtron
author_rank: Regular Contributor
timestamp: March 01, 2025, 04:25:54 am
content: This is 2oz copper from PCBWay. 0.5mm pad spacing so a bit larger, but spot on size and shape.

author: uer166
author_rank: Super Contributor
timestamp: March 03, 2025, 05:19:32 am
content: Wow that looks like shit! I've done 2Oz outer layer finished PCBs that looks 10x better with finer parts, however from my understanding they're actually 0.5 or 1Oz copper etched, then plated to 2Oz, otherwise the spacing needs to be much larger.

author: Vertamps
author_rank: Contributor
timestamp: March 03, 2025, 12:27:52 pm
content: That PCBway board looks great. Our order is underway with JLC pcb, i had to go in and adjust the trace spacing for them to accept my files. My spacing rule was set to 0.203mm instead of 0.2mm. Not that it matters but there computers caught the 0.003mm difference.

author: PartialDischarge
author_rank: Super Contributor
timestamp: March 03, 2025, 12:32:27 pm
content: Quote from: meshtron on March 01, 2025, 04:25:54 amWhat is the solder mask? Looks different than standard paints

author: wraper
author_rank: Unknown
timestamp: March 03, 2025, 12:42:55 pm
content: Quote from: PartialDischarge on March 03, 2025, 12:32:27 pmQuite common matte black.

author: Matt-Brown
author_rank: Regular Contributor
timestamp: March 03, 2025, 01:17:14 pm
content: The huge diference between the original and the PCBWAY ones are the NSMD pads. Tryimg to sodlermask between fine pitch leads to issues and I am pretty sure that is why the etching looks deep. That and etch line into pad

author: xavier60
author_rank: Super Contributor
timestamp: March 03, 2025, 10:13:29 pm
content: I get many boards done in 2oz from PCBWay, as this example,https://www.eevblog.com/forum/eda/when-to-use-osp-surface-finish-for-pcb/msg5806167/#msg5806167No problems except for a small mask misalignment.

author: meshtron
author_rank: Regular Contributor
timestamp: March 10, 2025, 07:57:25 pm
content: I use matte black for solder mask for no reason other than it looks sexy and I can. Board is buried within the product where nobody should see it, but I see them.