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Background: I'm watching many SMD soldering tutorials these days, but I'm still not ready (too nervous!) to actually try it with my PCB and DAC TI PCM5122PW:

Question: Can I put the SMD chip on the PCB and hold them together with Scotch tape during a few hours, and power on my PCB, to test it everything is working ? Will the SMD chip's pins be in contact with the PCB pads, if just held with Scotch tape?

Note: I'm not asking about using adhesive tape to hold the SMD chip for soldering purposes, but really for having, during a few-hours, real contacts between PCB and SMD chip.

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  • \$\begingroup\$ I wouldn't trust that contact, but I think it would likely work to some degree. Definitely don't rely on it to tell if your circuit will work or not, though. \$\endgroup\$
    – Hearth
    Commented Apr 26, 2017 at 0:54
  • \$\begingroup\$ Also, I have no idea if scotch tape is conductive or not. If it is, it might mess things up. \$\endgroup\$
    – Hearth
    Commented Apr 26, 2017 at 0:56
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    \$\begingroup\$ The risk of ESD damage is very real. Don't do it. \$\endgroup\$
    – Matt Young
    Commented Apr 26, 2017 at 0:58
  • \$\begingroup\$ Oh, good point. Didn't even think of that! \$\endgroup\$
    – Hearth
    Commented Apr 26, 2017 at 1:04
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    \$\begingroup\$ Learning to solder will probably be less frustrating than dealing with sketchy connections. \$\endgroup\$
    – Wesley Lee
    Commented Apr 26, 2017 at 1:16

2 Answers 2

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3M "Z-Axis" tape would be a better choice. It is placed between the part and the board, and is conductive through the tape but insulative along the tape.

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  • \$\begingroup\$ Now that's really handy. Adhesive zebra strips, in tape form. Might have to get myself some of that! \$\endgroup\$
    – Hearth
    Commented Apr 26, 2017 at 1:09
  • \$\begingroup\$ Oh really, such kind of tape would work for a small SMD chip like this DAC TI PCM5122PW? How would you estimate the chance of having all contacts working? It looks amazing! \$\endgroup\$
    – Basj
    Commented Apr 26, 2017 at 1:12
  • \$\begingroup\$ @Basj: The datasheet recommends 0.4mm spacing minimum, and Sparkfun has a video of a SMD ATmega328P working using it floating around somewhere. \$\endgroup\$
    – Ignacio Vazquez-Abrams
    Commented Apr 26, 2017 at 1:24
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Yes, technically you can, but it is not a good idea for many reasons, the main ones being that the contact is unreliable (which might lead you to believe that there is a problem with the components), if the board gets shifted while in use, the dramatic and repetitive changes in contact reliability could potentially damage the component, and if something shifts so that it is connecting the wrong pins, that could be bad for the circuit.

In short, yes you can, but it's not a great idea.

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  • \$\begingroup\$ Thanks. Is there another solution, that allows me to test, before doing a permanent real SMD soldering (I'm not ready! Too scared about doing a bad soldering right now!) \$\endgroup\$
    – Basj
    Commented Apr 26, 2017 at 1:03
  • \$\begingroup\$ More accurately, you can try but this is extremely unlikely to actually work with just tape over the top. Special Z-axis tape might do it, or something that could apply some force to compress the leads a bit, but not tape. \$\endgroup\$
    – Chris Stratton
    Commented Apr 26, 2017 at 1:30

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