How to fix a 'PCB' without mounting holes inside a case (or on a PCB)?

Question

I want to use several of the 'filled PCBs' below, or other ones, but the question does not change.

How can I fix such thing in a case, or on a proto/veroboard PCB (like the picture below)?

I thought about:

• Glueing: but since the case (including the components) will be moved a lot, it doesn't seem a good way.
• Using tie wraps, in this case it might work because it can be put around the yellow component, but what if I want to use another component that does not have a nice yellow box?
• Using one of the above methods with spacers to prevent contacts with the protoboard.

I don't need a professional solution, but I want a solution that doesn't break or getting loose after being 100 times moved neither.

Update

I asked a similar earlier question. However, this was about a temporary solution, in which I expected components need to be changed/added. However, in this case it's about a fixed/known setup. So I hope that a more professional (or at least 'better') solutions exist.

Answer 1

Use a box with card guides, (ie grooves in the walls) and fit a PCB card guide

Now the board / boards are horizontal and closing the lid locks everything in place.

Search for "P.C. Board Card Adaptors" or "Allows mounting of PC boards horzontally within the enclosure."

Answer 2

An Adhesive that has high bond strength, yet not brittle made of Polyurethane is about the best. Some UV cured Silicones are often used in Industry.

I have found this Polyurethane to be an very economical (cheap in bulk) and very reliable adhesive to improving the vibration isolation of components and rigidity of a structure. It is not brittle and has exceptionally high adhesion qualities far better than hot glue which might be a quick fix as well. The down side it the cure time for the low VOC versions avail. now is 1 to 3 days till fully cured if there is exposure to air.

Test a couple of sticks at the same time and you will be surprised at the strength. I also use it for carpentry such as mounting drawer slides where screws are not possible.

Here is a commercial solution from Dymax to prevent broken solder joints. You do the same with the Polyurethane subfloor adhesive, and also use it to adhere the corners inside the container, although the dispenser is more bulky.

If you look in any PC power supply, you will get the idea for securing any parts that can move first.

Apply to each moveable part with at least ~ 1 mm and the surface area determines the holding strength. Allow 1hr to get firm and 1 day to cure or so. Commercial solutions use accelerators.

Answer 3

It's a bit unclear, but I'll interpret your question as asking how to mount one of the boards in your top picture on one of the boards in the bottom picture. You say this will be "moved a lot", but it is unclear if you mean the individual sub-assemblies need to be movable within the larger device, or of the larger device will be subjected to vibration. I'll assume the latter.

It looks like the board modules have thru holes for the external connections. My first reaction is to use those holes to mount the module onto the prototype board. Line up the holes with where you want to connect on the bottom board, insert a wire thru both boards, and solder. To keep other parts of the top board from shorting to the bottom board in places other than the intended connections, use a insulating layer of cardboard or fairly rigid paper. In electronics assembly there is something referred to as fish paper that is used for that purpose. If you need additional mounting strength, use gobs of hot glue.

If you are just inter-connecting multiple modules without adding parts of your own, then connect them with wires and mount the board on something non-conducting with lots of hot glue.

Note that these modules are not designed for vibration. The two large electrolytic caps seem to be just hanging from their leads. That won't last long in a high vibration environment. You can make it more rugged by using hot glue or epoxy, but beware of adding too much thermal insulation in places that get hot.

Ultimately, these are not the components you should be using in a high-vibration environment.

Answer 4

I am assuming that's an AC-DC isolated power supply.

There should be at least 4 connection pads, two at the end shown (DC output) and two more at least at the other end (AC input). If those holes are ~1mm diameter you can mount the board on short pins inserted through the holes and soldered into your perf board. Either round pins (eg. see Mill-Max) or use the pins from some 0.1" pitch headers (0.025" square, so they are a bit loose in a 1mm hole). Cut them off in singles and use the plastic to space off and support the PCB from the bottom.

If you pick the right pins and sockets you can even make the boards plug in, however you'll have to find a way to retain the board.

Note: The holes that can be seen are filled with solder right now. If you have a decent desoldering tool, clearing them out is dead easy.

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Below you can see a similar product (but safety agency approved and from a reputable supplier) that happens to be inside a plastic housing, but the mounting is accomplished via the pins (perhaps stabilized with a bit of adhesive on the bottom):

Answer 5

3M VHB (Very High Bond) double sided acrylic foam tape onto the relatively flat bottom side of the PCB.

Answer 6

One could also solder stout wires to big and grounded solder joints or to the ground plane, then either make loops at the ends and screw down the loops, or just solder the other end to the carrier board (if mounting to a prototyping PCB) . NOT an acceptable technique, however, to mount a heavy and potentially mains connected (or able to touch anything mains connected should it come loose) module as shown in the first picture.

Answer 7

What I did for a small PSU board was solder header-type pins to the voltage in and out pads of the PSU (so 4 pins), secure the PSU board to the main PCB with double-sided sticky foam tape and solder the pins to the main board, which was Vero-board. The soldered header pins obviously stuck out below the PSU, in order to be soldered to the main PCB. This worked well.