How to remove a SMD resistor

[modeng2000Participant @modeng2000]

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

[modeng2000Participant @modeng2000]

[Martin ConnellyParticipant @martinconnelly55370]

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

[Joseph Noci 1Participant @josephnoci1]

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.

[modeng2000Participant @modeng2000]

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

John

[Anonymous]

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

[Grizzly bearParticipant @grizzlybear]

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

Good luck ………..

[noel shelleyParticipant @noelshelley55608]

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

[modeng2000Participant @modeng2000]

The resistor is approx 3mm long, value 110k

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

John

[Anonymous]

Posted by modeng2000 on 25/02/2022 10:52:58:

…resistor is approx 3mm long…

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

Andrew

[Joseph Noci 1Participant @josephnoci1]

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

[modeng2000Participant @modeng2000]

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

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