Immersion Gold PCB pads

Go To Last Post
11 posts / 0 new
Author
Message
#1
  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

Hi All

 

I got some old PCBs that had pads which are Immersion gold.

 

I used one of this boards for a prototype where i needed to connect  to a modules UART port directly with UART/USB dongle. I soldering a wire onto a AVR pad(empty pad), as these are connected to the module and i can connect the other end to the dongle.

 

While soldering the wire on the pad, the pad just detached from the PCB even though it was still connected to the track.

 

Is this normal occurrence as this is the first time i have experienced it?

 

Thanks

 

 

 

 

Thanks

Regards

DJ

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

Too much heat for too long will do that!   Yes it is normal if you take too long with the iron.

You may be able to do some repair using super glue, but that will not hold if you touch the pad again with a hot iron.

 

Jim

 

 

 

 

 

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

Yes, not uncommon with too much heat. Too hot, too long. Hope you did not rely on the through-hole plating for circuit connection elsewhere!

 

Jim

Jim Wagner Oregon Research Electronics, Consulting Div. Tangent, OR, USA http://www.orelectronics.net

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

Yes, i got a new soldering iron which has more power. Well this is simple prototype board, so i guess next time i will reduce the temperature when using it on pads.

 

Thanks

Thanks

Regards

DJ

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 1

djoshi wrote:

...next time i will reduce the temperature when using it on pads.

 

That's not the way to do it. You need the iron at the right temperature for the solder you use. All that happens with a cooler iron is that you take longer to make a joint and will do more damage.

 

What solder do you use and what temperature were you running the iron at?

#1 Hardware Problem? https://www.avrfreaks.net/forum/...

#2 Hardware Problem? Read AVR042.

#3 All grounds are not created equal

#4 Have you proved your chip is running at xxMHz?

#5 "If you think you need floating point to solve the problem then you don't understand the problem. If you really do need floating point then you have a problem you do not understand."

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

Due to no thermal relief, certain connectors GND pin were previously difficult to solder.

 

I had kept it to the highest, i think i will reduce the temperature till solder starts to melt.

 

I am using the chipquik solder paste, with 60W iron set to the highest.

 

 

Thanks

Regards

DJ

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

The chipquik paste that I have used had quite a low melting point. Dig out the datasheet and have a look.

#1 Hardware Problem? https://www.avrfreaks.net/forum/...

#2 Hardware Problem? Read AVR042.

#3 All grounds are not created equal

#4 Have you proved your chip is running at xxMHz?

#5 "If you think you need floating point to solve the problem then you don't understand the problem. If you really do need floating point then you have a problem you do not understand."

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

For most soldering I use 700F with 60/40 solder.

 

Jim

 

 

 

 

 

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

Yes, i think i will use a much lower temp when using pads, and when soldering connectors with no thermal relief i can increase it.

 

Thanks

Regards

DJ

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

ki0bk wrote:

Too much heat for too long will do that!   Yes it is normal if you take too long with the iron.

You may be able to do some repair using super glue, but that will not hold if you touch the pad again with a hot iron.

 

Jim

 

 

Super glue decomposes at a fairly low temp.  In fact it is common to use it as a temporary bond on a lathe or mill and then release with a small bit of butane flame.

 

Epoxy glue (Araldite is a common name in OZ) is much preferred.  You can even buy high temp variants of epoxy for this kind of thing.

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

Thanks

 

Its simple proto board. Once i am able to do what i require, i will make a new board But keeping in mind what i learnt not to do.

Thanks

Regards

DJ