I will so travel with some ICs to Europe from the USA soon. I am going to Europe for a research visit and I need those ICs there. I am not sure if this will create some problems for me during security checks or customs. Do I need to declare anything or carry some documents? I have traveled with ICs before with the USA and I asked my collaborators that they have done so also within Europe but we have no idea what happens in international travel. Please note that I am traveling in 2 days and currently both the universities are closed. Also, should I carry them in my carry-on or check-in luggage? Thank you for your help in advance.
Assuming this are non-trivial ICs: I would recommend shipping them separately.
Regulations around this are fairly complicated and shippers like FedEx, DHL or UPS (etc) have the infrastructure and experience to deal with the paperwork. If things get held up in customs, it won't affect your own travel. ICs don't weigh anything so shipping cost should be moderate.
The main risk here is that the ICs create discussion and confusion with customs or TSA and even if everything is correct and you have the correct paperwork it may delay you enough that you will miss your flight or connection.
I once travelled through Europe with non-trivial measurement equipment that needed to be imported/exported at every border crossing using a so-called Carnet. That often took a few hours to get the paperwork handled.
When travelling, there are several things to take into account:
Size and weight of your luggage, to stay within your allowances. In your specific case, unless you carrying hundreds of ICs, this shouldn’t be an issue at all.
Security scans. Some items are prohibited in the cabin or even altogether on a plane, or in some specific cases (such as lithium-based batteries) there may be restrictions. Again, in your specific case, I don’t quite see any issue here.
Export regulations. Some materials cannot be exported without declaration, authorisation, or even not at all. In your case some technologies may be impacted, but it’s unlikely (but without details of the ICs it’s just a guess)
Import regulations. Again, there may be regulations which limit or prohibit import. For instance wireless devices need to comply with local regulations, which may be very different. I have a hard time seeing such an issue with “raw” ICs (as opposed to complete devices or boards), but again, we lack details.
import taxes and duties. This one is much more likely to affect you. There’s a small personal allowance which is exempt from duty and taxes, but beyond that you are supposed to declare goods and pay taxes on them. If you are only visiting and will re-export the hardware when you leave you can be exempted from taxes, but for larger values it’s a good idea to use an ATA Carnet to avoid any issues.
So the answer is… it depends. If you provide more details it may be possible to give a more specific answer.