18

I recently got a Venmo card, which is my first card with contactless support. I was looking at the EMV pins and noticed a very weird design. In the middle of the ground pin, there is this long, thin pin extending into it that I've never seen before.

It has ~5 MΩ between it and the ground, so it doesn't seem like just an aesthetic feature. What does it do (and why isn't it on most cards)?

Venmo card

wovano
  • 161
  • 2
  • 11
Ian Carroll
  • 181
  • 3
  • 4
    I'm curious now too, I guess it's possible that it is an oddly precisely placed specialized contact pad, but if I really had to guess, I'd say it's a via (place where a circuitboard had to jump layers to make connections between places on another layer, and the spec for that center contact pad probably only require some other specific part be a pad, with the extra space accounted for by what is called a pour in circuit board design. – K H Oct 04 '18 at 03:07
  • 9
    the people that know are probably sworn to secrecy – jsotola Oct 04 '18 at 05:58
  • 2
    That's probably one of the connectors for the antenna loop for the contactless part. – KristoferA May 09 '21 at 08:16
  • 2
    The chip on a chip card lived under the contact pads you are looking at. And since this card needs an antenna (coil inside of the card) the two wires need to come out in some way to be connected to the same piece of silicon. My card has a via and it is happening in an inner layer. Here the "FAB designer" probably figured out how to make the same more effectively. – Martin Vana Sep 21 '21 at 02:03
  • 1
    Could be some 'manufacturer only' pin, for factory testing or programming and the final equipment is not expected to mess with it – Lorenzo Marcantonio Jun 22 '22 at 10:00

1 Answers1

1

I don't recognise the pattern, but it can change depending on the manufacturer. I think what you are describing is a guard pin.

When a card with a guard pin is inserted into a card reader, the guard pin makes contact with the reader first. This allows the reader to verify that it is a legitimate card before the main ground pin makes contact and the card's data is read. If the guard pin does not make contact, it could indicate that the card has been skimmed or is otherwise not legitimate, and the transaction will not be completed.

Not all cards have this feature, as it is not required by all payment networks. However, it is becoming more common on cards with contactless payment capabilities, as it can help to protect against skimming attacks on these types of cards.

Masteredgod
  • 13
  • 2