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I have a prototype board like this, on which I plan to add some solder traces (the black lines).

enter image description here

I plan to place a BNO055 on top of this same prototype board and solder it in place without using header like this:

enter image description here

It is intended that there is a connection from the Pads to A8,A6,A5,A4 to coincide with Vin, GND, SDA and SCL.

I was wondering if I need to place some insulating material like tape between rows B-G to insulate the breakout board from the PCB ? I intend to have a connection from 3vo (A7) to ADR (H4), and intend to place a connector on K(4-7).

Is insulation tape necessary ? Or is the breakout board already insulated, and the traces being in contact with the board shouldn't matter ? Any other suggestions about what is wrong with this approach ?

The reason for my approach is: 1. I don't have access to any parts or tools to place all the individual components on the prototype board itself, so as a quick hack I'm trying to just place the breakout board on the prototype board without headers (through-hole soldering). 2. I would like to minimize height and footprint.

Thanks.

Kaizer Sozay
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  • @jsotola I don't understand - what are pads ? All I see are the soldering holes for Vin, 3vo etc.... – Kaizer Sozay Mar 13 '20 at 05:49
  • @jsotola Some people say that removing the pad may result in increased mechanical stress on the remaining pad. What if I just added insulation tape to the bottom to prevent contact of the bottom pad with the PCB ? Is it a bad idea? Any special tape required ? – Kaizer Sozay Mar 13 '20 at 05:55
  • @jsotola Why do you keep deleting your comments ? XD – Kaizer Sozay Mar 13 '20 at 06:02
  • @jsotola ah ok! – Kaizer Sozay Mar 13 '20 at 06:08
  • @jsotola is double sided foam tape insulated ? No risk of catching fire from heat generated by the connections / trace ? – Kaizer Sozay Mar 13 '20 at 06:09
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    i have not thought about fire resistance ... i am prety sure that it is a good insulator .... there are different kinds available ... fire resistance would have to be determined as well as insulation strength – jsotola Mar 13 '20 at 06:15
  • @jsotola I guess unlikely since the sensor draws max 40ma? – Kaizer Sozay Mar 13 '20 at 06:16
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    over heating or fire is really a rare case for the voltages and currents you have mentioned. one suggestion: use simple wires instead of crating a solder trace. – User323693 Mar 13 '20 at 09:54

1 Answers1

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Is insulation tape necessary ? Or is the breakout board already insulated, and the traces being in contact with the board shouldn't matter ? Any other suggestions about what is wrong with this approach ?

enter image description here

Shown above is the bottom side of this BNO055 PCB.
Most PCB's have a solder mask, a protective and non conductive coating. It is applied to the copper layer (light blue coloured) and layer where copper has been etched away (dark blue coloured).
It is not applied to SMD and through hole pads (brown/gold coloured) (otherwise you couldn't solder on them).

So, you don't need to worry about columns D, E and F.
However, the right bottom mounting hole may short the traces on (row 01 and 02) and columns (G and H).

In this case, you can just use any adhesive non-conductive tape to isolate the pads and mounting holes of PCB or the whole bottom side of the PCB, because the voltages are low and there is almost no heat generated on the PCB.

Huisman
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    I do not necessarily disagree with your advice, but I feel you should distinguish between "conformal coating" and "solder mask". The light/dark blue coating you're referring to is the solder mask, whereas a conformal coating usually refers to additional high dielectric coatings often used for isolation and safety purposes. – 1N4007 Mar 13 '20 at 13:52
  • @1N4007 You're correct. I used the wrong term. I'll correct it. The difference is explained here – Huisman Mar 13 '20 at 13:58