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The tiny chip that powers Montreal subway tickets

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Re: The tiny chip that powers Montreal subway tickets

#141

Post by kccqzy »

Sytten wrote: post #108

They are going away soon (TM), the tech is cool but they are impractical. I will be happy to use my credit card or phone. Too many times I have been stuck in 15-20 minutes queues to buy those tickets and you cant refill them with an app... Plus south shore and north shore have they own system it's a mess.

It is theoretically possible to refill it with the phone. You either have a stored value card where the value is stored on the card and have the phone's NFC talk to it, or you store the value in a server that has an API to add value and have the reader at the subway deduct the value from the server.

Re: The tiny chip that powers Montreal subway tickets

#142

Post by akpa1 »

chgs wrote: post #139
akpa1 wrote: post #124

Earlier quoted context omitted.

I'm looking forwards to the day they somehow manage to link a National Railcard to a contactless bank card.

You’d have to have a national railcard first. The only railcards that exist are specific ones for specific groups.

National Railcard is the name that TfL uses to refer to all of those different types of card.

https://tfl.gov.uk/fares/free-and-discounted-travel/national...

Re: The tiny chip that powers Montreal subway tickets

#143

Post by II2II »

markus_zhang wrote: post #98
justusthane wrote: post #21

This is fascinating. We were just in Europe where we experienced these tickets for the first time. I had trouble with them; I was trying to figure out how to scan them because it never occurred to me that they might contain an NFC chip. My wife, on the other hand, who is not at all technical, took it for granted that you would tap them and immediately figured it out intuitively.

I have found the same thing with my wife. I'm a technical person, but I'm extremely bad with tools and such, including the ticket thing. If no one shows me how to use it I'll probably figure out a way to insert it somewhere. My wife won't have any problem with this and other small tools. The same thing with IKEA: I always rely on the manual and just blindly follow the instructions, and gets very frustrated if the ins…

> The same thing with IKEA: I always rely on the manual and just blindly follow the instructions, and gets very frustrated if the instructions miss one step.

Following instructions is a good thing. Plenty of people damage stuff when putting it together since it looks obvious, but they usually miss critical details. I would imagine that the people who designed the card scanners had to put a lot of thought into their design simply because they know many people won't read instructions and would do as you suggest: figure out a way to insert [the card] somewhere.

Re: The tiny chip that powers Montreal subway tickets

#144

Post by [deleted] »

bobthepanda wrote: post #129
kens wrote: post #25

Earlier quoted context omitted.

I don't like the e-waste aspect either, but realistically, the chip is so minuscule that the amount of waste is trivial compared to almost anything else you might discard. The chip is literally the size of a grain of salt. The other factor is that people who use tickets regularly would use the rechargeable plastic cards, rather than the disposable tickets, so the amount of waste is reduced.

I don’t really see why a chip is needed at all for single use tickets. Those have existed forever and there are a plethora of non-chip options ranging from the simple holepunch to the optical printed barcode or QR code.

[deleted]

Re: The tiny chip that powers Montreal subway tickets

#145

Post by kens »

MBCook wrote: post #131

The article says the chips are made on a 180 nm process and they come out about the size of a table salt grain. We’re now down in the single digits for fabrication in nanometers, although I know that sort of just a name. This chip is so tiny already, if you were to fab it on a process like 7 nm I’m guessing it would be unworkably small. Too hard to cut, too hard to manipulate individual chips once you did manage to c…

There are a few issues. First, you lose 20 µm due to the saw cut between the dies. I saw an NXP patent that said this was wasting 30% of the die for their tiny chips. If you made the chips smaller, you'd be wasting even more. Another issue is that you need some area for the bond pads, so you can't make your chips arbitrarily small or they will be useless.

Looking at a random die pick-and-place machine [1], it handles dies down to 0.2mm in either dimension. So you could handle smaller dies than mine with an off-the-shelf machine, but not a lot smaller.

[1] The video of the die machine in action is pretty cool: https://www.syagrussystems.com/dts-2-die-sorter

Re: The tiny chip that powers Montreal subway tickets

#146

Post by kccqzy »

dheera wrote: post #101
b112 wrote: post #53

Earlier quoted context omitted.

I don't know how many times I've been in a city for a single day, or part of one, and have zero interest in spending precious minutes finding, buying, and returning a card. Just let me pay with coins, or a credit card in seconds, with no return work.

I believe Singapore's public transit does support tapping a credit card directly at the gates now, but there's an annoying step of having to register your card in advance on an app before it actually works. My guess is this might be because on-the-fly credit card authorizations still take too long. Waiting 3 seconds for an EMV contactless verification would seriously hold up the line at rush hour in a country where m…

Credit cards do not require online authorization.

Re: The tiny chip that powers Montreal subway tickets

#147

Post by kens »

rwmj wrote: post #103
kens wrote: post #90

Earlier quoted context omitted.

It's manufactured pretty much the same as any other chip, using photolithography. Most of the analog components would be CMOS transistors, just larger. They might use a BiCMOS process with a few extra steps to make bipolar transistors. And there might be an extra step for the capacitors. But overall, the chip uses an old, simple manufacturing process, much easier than cutting-edge processors.

The chip seems like it's almost too small? I don't even know how they would cut up the wafer and how they would pick each die and mount it in the paper card.

They cut the wafer apart with a diamond blade, 20 µm thick. Laser cutters can make thinner cuts, but they cost more. Die pick-and-place machines can manipulate even smaller dies at high speed: https://www.syagrussystems.com/dts-2-die-sorter

Re: The tiny chip that powers Montreal subway tickets

#148

Post by b112 »

dheera wrote: post #101
b112 wrote: post #53

Earlier quoted context omitted.

I don't know how many times I've been in a city for a single day, or part of one, and have zero interest in spending precious minutes finding, buying, and returning a card. Just let me pay with coins, or a credit card in seconds, with no return work.

I believe Singapore's public transit does support tapping a credit card directly at the gates now, but there's an annoying step of having to register your card in advance on an app before it actually works. My guess is this might be because on-the-fly credit card authorizations still take too long. Waiting 3 seconds for an EMV contactless verification would seriously hold up the line at rush hour in a country where m…

Interesting, and this hypothesis shows why twmp cards might be preferred.

I have no issue with temp cards, if I can buy them right at the pickup location. I once flew into a place late at night, and only stores had cards to buy, and all were closed.

Duh.

Re: The tiny chip that powers Montreal subway tickets

#149

Post by ghaff »

michaelt wrote: post #128
TheJoeMan wrote: post #106

Earlier quoted context omitted.

Does the card not have the three-arcs nfc symbol? Similar to the wifi symbol. To me the fake printed dip-chip is more confusing!

Most metro stations have a much simpler way for travellers to figure out what to do: of loads people who do know how it works, ahead of and beside you.

It's getting better but, in my experience, once metro systems got away from manned booths and tokens, the systems worked fine for commuters but led to lots of fumbling and long lines for tourists.

Trains in the UK still have a certain amount of "Which of these tickets/receipts go where?" while a line of irritated locals is building up behind you. Fortunately, also being the UK, someone will help you if you're struggling with something sooner rather than later.

Re: The tiny chip that powers Montreal subway tickets

#150

Post by dheera »

b112 wrote: post #148
dheera wrote: post #101

Earlier quoted context omitted.

I believe Singapore's public transit does support tapping a credit card directly at the gates now, but there's an annoying step of having to register your card in advance on an app before it actually works. My guess is this might be because on-the-fly credit card authorizations still take too long. Waiting 3 seconds for an EMV contactless verification would seriously hold up the line at rush hour in a country where m…

Interesting, and this hypothesis shows why twmp cards might be preferred. I have no issue with temp cards, if I can buy them right at the pickup location. I once flew into a place late at night, and only stores had cards to buy, and all were closed. Duh.

Yeah that's a stupid system and I've seen it in many places. Being asked to go to to get the official public transit card, even the dude at the station couldn't sell me one.

The vending machines at every station should be capable of directly vending public transit cards. I think most of the better systems around the world do work that way.

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