Gold plating HASL edge connector? - Page 1
Forum section: electronics / general

author: [Chrille]
author_rank: Contributor
timestamp: December 14, 2023, 08:58:14 pm
content: Hi,I would like to know if it is possible to plate parts of a board that has been manufactured using HASL (covering the entire board).What I want to achieve is to be able to add hard gold plating to the edge connectors of some existing PCB's that do not already have gold plated edge connectors. I guess you would have to remove all the solder from the existing fingers and maybe even sand all of them down to until you reach the bare copper (which is a lot of work) and then plate them.Have any of you guys tried this? It is insanely expensive to have a PCB manufacturer create a board with HASL combined with hard gold plated edge connectors. It is mostly not an option for us hobbyists.

author: Smokey
author_rank: Super Contributor
timestamp: December 14, 2023, 11:59:27 pm
content: Not sure what your board spec is, but at JLCPCB for a 100x100mm 4 layer board, 5pcs...ENIG = $16.50 surface finish additional cost.Gold Fingers = $0.00 additional cost.That's pretty reasonable actually. ENIG is way better than HASL anyway.1000 pcs of that spec is a total of $964.80 for the boards. That's less than $1 per board for almost 4" x 4".

author: Whales
author_rank: Super Contributor
timestamp: December 15, 2023, 03:37:20 am
content: Chrille: Are these boards that you can make more of, or have they already been manufactured by someone else?

author: [Chrille]
author_rank: Contributor
timestamp: December 15, 2023, 11:57:49 am
content: Quote from: Smokey on December 14, 2023, 11:59:27 pmThe "gold fingers" you refer to are not really what you normally call gold fingers. When you select the gold finger option at JLCPCB you only get another option (edge chamfer). The gold fingers they provide have the same surface finish as the rest of the board (ENIG instead of hard plated gold). Real gold fingers are electroplated separately from the rest of the board and use a lot more gold which makes them more durable and have a much nicer finish.JLCPCB does not have an option for real gold fingers, but other manufacturers like PCBWay have such options. The problem is that they charge about $270 as a extra for real gold fingers (5 PCBs, 100 x 100 mm) so you basically end up paying almost $300 for 5 small 100 x 100 mm boards, which is insane.

author: [Chrille]
author_rank: Contributor
timestamp: December 15, 2023, 12:00:18 pm
content: Quote from: Whales on December 15, 2023, 03:37:20 amIt is mostly boards that I have created so I could get them re-manufactured.

author: wraper
author_rank: Unknown
timestamp: December 15, 2023, 12:23:14 pm
content: As gold fingers are entirely separate process, nothing prevents covering edge connector with kapton tape during HASL. I did not research what PCB manufacturers actually offer, but fundamentally nothing prevents it.EDIT: I re-read and understood that you want a DIY solution. It would be absolutely stupid, extremely difficult to remove solder entirely, and in no way would save money compared to just ordering boards with ENIG.

author: langwadt
author_rank: Super Contributor
timestamp: December 15, 2023, 12:33:32 pm
content: Quote from:  on December 15, 2023, 11:57:49 amfor a hobbyist and not needing to repeatedly plug and unplug ENIG might be good enoughalso to get real hard gold finger the pcb needs to be made with a shorting bar connecting all the fingers that gets milled off after plating

author: onsenwombat
author_rank: Contributor
timestamp: December 17, 2023, 09:25:01 am
content: Another thing I'd recommend being aware of that as the aforementioned JLC is that quite a few PCB fabs, even those that proudly market themselves as sort of premium house, have their gold fingers in practice nothing beyond your typical ENIG. Have also witnessed the typical "samples were ok, but all of a sudden in mass production things took an unexpected turn" case regarding this.So, know your house until you pay your big bucks for any gold fingers. For OP's case, I'd agree with the poster above.

author: factory
author_rank: Super Contributor
timestamp: December 17, 2023, 10:47:04 am
content: Quote from:  on December 15, 2023, 11:57:49 amJLCPCB don't cover the whole board with ENIG as standard, only the exposed pads & connections, they ask for extra $$ if you want ENIG for the whole board, i.e. to recreate an old board that didn't have soldermask.Some vintage stuff used nickel plating for PCB edge connectors, don't use any solder based finish if it's plugged into a gold finished socket, it will get stuck, warning from an ex-HP designer here.https://www.vintage-radio.net/forum/showpost.php?p=542418&postcount=9David