Reliable connectors?

How reliable are this types of connectors (male part show on image) compared to ICs in a socket over time?

It's bad connection that worry me.

As long as there's no wiggling of the connectors going on, those contacts will be quite durable. If the device is subject to a lot of movement and shaking etc., I'd consider something like the JST XT series.

It really depends on the environment the board will be in (temperature, dirt, moisture) and if the female header has gold plated connectors.

The crimping is of utmost importance.

Female connectors I have crimped have never failed, however, all have been inside clean environments.

The PCB which the female connector is attached to, will be inside a box mounted on a wall. So movements are not my concern.

The box is sealed but can be opened (to operate the keypad). So moisture is what concerns me. The box will be inside a non-insulated room near the sea.

I will put a silica gel packets inside the box to keep the amount of moisture down.

Crimped? How?

Suggest you forget the gel and have some ventilation.

It's not this kind of female connector I use. It's the kind on this picture.

That will cause problem with corrosion. Everything outside have to be stainless steel to avoid corrosion.

As I wrote - this box will be exposed to moisture from the sea. The salt will cause problem over time.

Why are you using this type of connector? Do you expect to need to replace the ads1115 board? If not, it would be more reliable to simply solder the pin headers into a PCB/stripboard/protoboard.

That is why I ask. All the ICs are mounted in sockets so I thought maybe use this kind of connector on this modules.

I have thought about soldering them directly to the PCB.

The superior solution of course would be to make a custom pcb for this. Is that by any chance feasible for you? Even for one offs commercial pcb manufacturing houses are affordable these days, I understand.

Making a custom PCB is NOT an option. I may be affordable outside Norway. But in Norway we have to pay VAT. And if the VAT is not prepaid when ordering, an extra fee of ~USD 20 will be added... making one PCB very expensive.

So I will be using prototype PCBs.

Yeah, I'm in europe too and the new VAT regulations are a bit of an issue. Truth be told, I do my PCB's at home, but it's a bit of an endeavor, especially if you don't intend to do many.

I think the usual reasons for using sockets for IC's are 1) the risk that the chips might fail and need to be replaced; 2) the risk that the chips could be damaged during soldering.

A good reason not to use sockets would be where sockets would increase unreliability of the circuit, because of vibration or corrosion.

So you have to balance the risk of using sockets against the benefits, for each project's situation.

You can reduce the risk of damage during soldering by using appropriate equipment like a temperature-controlled iron designed for electronics work, and a small bit. I use a 1mm chisel bit and 0.5mm solder wire (with flux core) for soldering chips and other small components, and, for larger connectors, a 2.3mm chisel bit and 1mm solder wire.

Cleaning any tarnished pads or tracks is also important so that the joints can be made quickly and with minimum heat. A solder pen also helps with making speedy joints.

But the other important piece of equipment in hand-soldering is... the hand! Practice on cheap components and off-cuts of stripboard to improve your technique. Maybe even make a few practice joints immediately before soldering your project.

I have found that modern chips are extremely reliable and surprisingly tolerant of being hand soldered. I have at least one atmega328 working perfectly in a project after having been soldered and de-soldered from a PCB 4 or 5 times over!

The only part I have a bad habit of ruin during soldering is LEDs.

A couple of thoughts:

  1. If you don't solder to the board, be sure to NOT mix gold and tin contacts. Either both gold or both tin.

  2. If you are near salt water I would suggest some conformal coating. I like silicone spray but if not available, GE II silicone calk at home depot (or eq) is usable. DO NOT get the type I which smells like vinegar as it cures.

  3. Not sure what you're measuring but near salt water you must watch every connection, especially if you are expecting any type of accuracy.

About gold/tin - that was new information for me. Thanks. Since I do not have anything with gold contacts, I don't have to think of it (yet).

Coating of some kind may be a useful suggestions.
I'm using IP66 boxes and only water-proof connectors so I hope I do not have to use coating.

Maybe I put together a small PCB, connect it to power and leave next to the box (and fully exposed for the environment) and see what happens with it during the autumn/winter period where the weather is most likely to cause damages.

I've seen a lot of the male parts (as shown in your post) that are gold plated. I've not seen any female contacts plated in gold, although they can be purchased through a distributor (digikey or mouser etc).

Your test board is a good idea. You should make sure it is powered while in your test box. Power makes a big difference when corrosion is of concern.

I’ve purchased them from Pololu too.