Inside a RFID race timing chip: die photos of the Monza R6

Posted on Tuesday, November 1st, 2016 in reversed, RFID by DP


Ken Shirriff took some die photos of the Monza R6 chip  and wrote a post on his blog on how the RFID timing chip works:

I recently watched a cross-country running race that used a digital timing system, so I investigated how the RFID timing chip works. Each runner wears a race bib like the one below. The bib has two RFID tags, consisting of a metal foil antenna connected to a tiny RFID (radio-frequency identification) chip. At the finish line, runners pass over a pad that reads the chip and records the finish time. (I’m not sure why there are two RFID tags on each bib; perhaps for reliability of detection.)
The die photo below shows the RFID chip used on these tags. To create it, I took 22 photos of the chip with my metallurgical microscope and stitched them together to create a high resolution photo. (Click the image for a larger version.) To prepare the chip, I removed it from the plastic carrier with Goof Off, dissolved the antenna with pool acid (HCl), and burnt off the mounting adhesive over a stove. This process left the chip visible with just a bit of debris that wouldn’t come off. I’d probably get better results with boiling sulfuric acid, but that’s too hazardous for me. I described the image stitching process in this article.

More details at Ken Shirriff’s blog.

This entry was posted on Tuesday, November 1st, 2016 at 3:04 am and is filed under reversed, RFID. You can follow any responses to this entry through the RSS 2.0 feed. You can skip to the end and leave a response. Pinging is currently not allowed.

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