Remove glued Coin Cell Battery from circuit board

[japz87]

Hi everyone,

I'm in the middle of a maintenance service to an industrial controller, and want to replace some of the Coin Cell Batteries installed in the circuit boards.

The thing here is that the batteries are glued to the board so I think I'm gonna need some kind of glue remover or something like that, but obviously I need it to be "friendly" with the components and PCB protection layers.

Here I attach a photo of the board and there you can see the batteries glued to it. I have no idea what kind of glue it was used, I don't know if there's some kind of special one used on circuits or whatever, so any help would be appreciated.

Thanks in advance for your help!

 

[ads-ee]

Maybe it's hot glue, if so try this out:

 

[BradtheRad]

If it turns out to be silicone, then it will be a chore to remove.

It looks as though the metal tabs are firmly connected to the board. The upper one at right, the bottom one at left. It is very risky to pry upward on the batteries, because you might lift those tabs, which could rip up the board.

Before you pry upward on the batteries, see if you can detach those tabs. I would use my wire cutters, or tiny grinding wheel.

Do not do anything to bend the board. This could break components or copper traces.

 

[japz87]

Thanks, I'm aware of that, that's why I thought it would be safer to use some kind of solvent remover that softened the glue for easy removal.

I'll keep searching...

 

[FvM]

It looks like silicone rubber which is soft and must not be neccessarily removed when changing the batteries. The more interesting point is to desolder the battery tabs properly.

I wonder if the board has been originally shipped with silicone attached batteries? It doesn't look very professional. I would normaly expect battery holder in place of the soldered batteries.

 

[ads-ee]

The OP needs to say whether or not it's a hard or soft material.

 

[japz87]

I was not originally the one that found these boards, that was a partner of mine and now the job has been passed to me. All I have is the picture on the original post and the poor description that the glue is some kind of hard silicone.

Me posting here was to find if maybe there was some kind of glue particularly used on circuit boards and if there was a proper way to remove it.

As far as I know the board came originally that way, and no, in my experience working with electronics have never seen a battery placed like that, as I know there are battery holders and sockets for the matter.

If anything else comes to mind I'll be reading here your ideas and suggestions.

 

[FvM]

There's no chance to remove silicone (also epoxy or polyurethane resin) with a solvent without damaging other components, e.g. sockets or connectors. If it's silicone rubber, you can peel it off or carefully cut it with a knife. If you want to apply new silicone rubber, you must use an acid-free electronic quality.