PCB houses

PCB houses.

Does anyone know of one which offers either lead solder HASL finish please or one that offers a plain copper finish WITH solder resist.

Required for long term storage.

  1. All of them.
  2. None of them. You can't solder through solder resist so the copper must be bare on the pads, which will corrode in the long term.

ENIG is good for storage too.

MorganS:

  1. All of them.
  2. None of them. You can't solder through solder resist so the copper must be bare on the pads, which will corrode in the long term.

ENIG is good for storage too.

I mean solder resist applied normally just the pads being bare copper without any surface treatment/plating.

ENIG is better but i am hoping for 5 years plus, gold is too expensive.

6 months is generally quoted for ENIG

Have you tried vacuum sealing with included dissacant package? We had to do that with boards that had silver plating and it worked pretty well. Still had to use tarnish remover before we populated the boards.

Paul

Yes the existing demon boards were stored in dry nitrogen.

I suspect an intermetallic layer formed due to some error when i ordered them and did not get what i expected.

Silver plating i did not think of , who offers it ?

Gold has to be better than silver. Silver actually corrodes in air. Gold doesn't.

The 6-month lifetime is for a specific process. Like if you are going to put them straight into a wave-soldering machine. If you modify your process to have a pre-bake and clean stage immediately before populating then the life of the board should be decades.

Why order too many boards to start with? Just order them when you need them? Or solder the critical components before storage?

They are for header boards for mounting SMD to pins.
I had a selection made so i could just grab one when needed.
No 3 week wait.

Gold would be expensive.
Enig i have used over a year old but am not sure about the longer term.

I could reorder every year i suppose as they are not that expensive.
Seems a bit wasteful though.

Are you having problems with the boards currently or are you worried about the future? I've had both tin and gold plated boards sitting open in the lab for years and been able to use them. The life guidelines listed are for production boards with warranty concerns. This is very different than lab or hacker setups that just have to work and can be repaired in a few years if necessary.

Gold will last for many many years with no deterioration. Even with tarnished tin plating I've been able to make a decent electrical connection for a lab setup.

This thread explains more.

I think i will try to get a professional phototool for the solder resist and make them as needed.