How to remove a SMD resistor

I would like to be able to remove a SMD chip resistor. Unfortunately it has been fixed with adhesive and soldered. I assume the adhesive won't soften with heat so what is the best way to approach this?

John

The controls department where I used to work used a hot air tool specifically designed for this type of thing. Looks more like a soldering iron than a hairdryer.

Martin C

Heat does work even if the adhesive is epoxy, etc. Use 20-40watt iron with a tip that can cover both ends of the SMD, put a blob of solder on the tip and apply to the smd - keep it in contact with both ends for 10-15sec. Use a small jewellers type screwdriver to gently prod at the smd every few seconds - it will move away..

This will not work well if the PCB is phenolic/resin impregnated paper, etc - works fine on fibreglass pcb's - FR4, etc.

Hot air may work, but will take longer and will heat the surrounding bits more than necessary.

Thanks both for your helpful replies. The pcb is fibreglass so I'll give it a try.

John

How big is the resistor and what sort is it? For standard thick film chip resistors I use two 80W irons, one on each end. Even with glue once the solder is molten the resistor can be removed by pushing gently with the irons.

Andrew

How To Remove Surface Mount IC/smd IC - Learn 4 Neat Methods - YouTube

Good luck ...........

I would use hot air, especially to fit a new one. Use foil to protect other components around the site.Noel.

Edited By noel shelley on 24/02/2022 21:27:36

The resistor is approx 3mm long, value 110k

I'm sure it will let go with sufficient heat on both tags.

John

Probably 1206, ie, 120 thou by 60 thou, or 3216 in metric. Huge, should be no problem removing it.

Andrew

Is the resistor broken/open cct? Do you need to fit a different value? If you need a lower value, put a suitable value in parallel - easier than removing the present one. If you need a larger value....

Joe

Thanks Andrew.

Joe, I believe it is o/c and will consider paralleling with a conventional resistor for test purposes if this is the case.

Not sure if there is room to leave a wire-ended resistor in place when reassembled.

John