JLCPCB copper core PCB differences - Page 1
Forum section: electronics / general

author: dkonigs
author_rank: Regular Contributor
timestamp: March 25, 2025, 12:14:54 am
content: I recently had a batch of PCBs made using JLCPCB's direct heatsink copper core PCB service which is described here:https://jlcpcb.com/blog/JLCPCB-Direct-Heatsink-Copper-Cored-PCBs-Available-Now!Among the batch I received, there appear to be two distinctly different manufacturing processes that got used. Its best shown visually, so here's a picture of the two side-by side:The top row is the top of the boards, while the bottom row is the bottom of the same boards.The majority of the boards look like the ones on the left side. The bottom copper is clean, and the top copper has a slightly dull matte finish.However, a few look like the ones on the right side. The bottom copper on those is very much scuffed, and the top copper has a darker shiny finish.What's going on here?The order form suggests that they put an OSP coating on the boards, so did they coat one and forget to coat the other?Functionally, as bare boards, the ones on the left seem to have half the trace resistance as the ones on the right.Otherwise, I think I've only assembled boards like the ones on the left thus far, and they all seem to work fine.

author: UnijunctionTransistor
author_rank: Frequent Contributor
timestamp: March 25, 2025, 01:25:43 am
content: A Snafu? Was the copper laminate stored without any protective coating, allowing the surface to become corroded?Have you attempted to solder components on a stained board?I would place a complaint with JLCPCB. At the very least they owe you an explanation.

author: Kean
author_rank: Unknown
timestamp: March 25, 2025, 01:30:45 am
content: I can't tell if there is something else different, but yes it looks like they forgot the OSP coating on some panels.Does the texture of the bottom sides feel different? The OSP coating may have just hidden any scuffing on the others.A possibility is that they had some bad panels in the original job and had to make extra using copper sheet from a different (more scuffed) batch, and then in their rush they also forgot the OSP step.

author: JLCPCB Official
author_rank: Regular Contributor
timestamp: March 25, 2025, 03:05:39 am
content: Quote from: dkonigs on March 25, 2025, 12:14:54 amThank you for your feedback, and we apologize for the inconvenience. After investigating, we found the issue: the PCBs are split into two parts for OSP processing, and one part was mishandled due to worker oversight. We are addressing this internally to prevent future occurrences. Our after-sales team will contact you shortly regarding compensation.

author: UnijunctionTransistor
author_rank: Frequent Contributor
timestamp: March 25, 2025, 05:10:03 pm
content: Good! At least the ‘fessed up.Scheiße can happen to anyone, the best companies acknowledge the error and compensate you accordingly.

author: dkonigs
author_rank: Regular Contributor
timestamp: March 25, 2025, 08:02:06 pm
content: Quote from: UnijunctionTransistor on March 25, 2025, 05:10:03 pmYeah, and fortunately its no big deal this time. They've already reach out and all is good.I ordered more boards than I actually need at the moment (since the incremental cost is minuscule), so its not a big problem but it is good to know that this was a one-off issue.