Friday, September 14, 2012

Difference between a mini SIM and a nano SIM

Click for (very) high resolution version.
A standard-sized SIM that is used in most phones is actually a "mini" SIM card. The image above shows a photograph of my Docomo Xi mini SIM card with dimensions. It is 15 mm wide and 25 mm long. Chopping this down (for use in an iPhone 5) to nano SIM size length and width would be easy.

The difficult part would be removing the 90 µm of plastic from the bottom to bring the thickness down from 0.76 to 0.67 mm. As you can see that isn't a lot of plastic and it could likely be done by sanding/filing down the back. Perhaps the best way to do would be to file it down a bit and try and insert it. Then file some more if it doesn't fit and so on.

Looking down on the same SIM as pictured above
As long as it is thin enough to fit in the slot but thick enough to maintain contact. Speaking of contact, I believe the contact arrangement is the same between each SIM type.

10 comments:

  1. In fact, the contact points are identical. The plastic has changed, the chip has not.

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  2. Hey! I just moved to tokyo with a friend and he got the bmobile 3g micro sim with the 1gb plan for his iPhone 4S. Uppon arrival we noticed that the chip on the bmobile micro sim was much bigger than the chip on his previous sim card. I was planing on getting the bmobile 4g sim card but now I'm concerned that the chip will be to big. I wanted to get the iPhone 5 and cut the micro sim so it fits but after seeing the mico sim of my friend I'm affraid that it won't work due to the chip beeing to big.

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  3. So, the big question is -- will b-mobile offer nano-sims? Or will cutters work fine without dealing with the width issue?

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  4. Hi Robert, I'm actually in Japan ATM and purchased a b-mobile Micro-SIM (which I would normally use with my iPhone 4S and it doesn't work. The b-Mobile Micro SIM's contacts are much larger than a conventional Micro SIM, so when I used my SIM cutter it actually cut a significant portion of the copper contacts, which I believe left the card unusable. Such a shame since this was my go-to way of using internet in Japan. Guess I'll be buying a mobile hotspot for use from now on.

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  5. Somethings wrong. There are tons of people using b-mobile micro SIMs with unlocked iPhones. They are extremely popular.

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  6. Some people were successful in cutting Docomo/b-mobile micro-sim to nano-sim. http://www.lasical.com/2012/09/22/22596/

    Try using this guide, instead of the nano sim cutter.
    http://www.airportal.de/nanosim/

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  7. Some people were successful in cutting docomo sim card. http://www.lasical.com/2012/09/22/22596/

    Or just follow this guide, instead of using nano sim cutter: http://www.airportal.de/nanosim/

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  8. Looks like Docomo will start providing nano sim from Nov 1, which means you can get one from b-mobile too.

    http://k-tai.impress.co.jp/docs/news/20121030_569560.html

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