Plastic eSIM info and eSIM Failure Diagnosis

SIM/eSIM/eUICC all used interchangeably below.

Across our many eUICC vendors, the out of the box SIM chip failure rate can be expected to be less than 1 in 1000. This is one reason why it is important to test your device before deploying into the field to make sure that the SIM is not DOA. Depending on the environment, and under very rare circumstances, plastic or embedded eUICCs can also stop working in the field. When this happens it can be very frustrating but it is important to identify the root cause of this so that further issues can be prevented if possible

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Root Cause of eUICC Failure

In order of frequency of occurance:

1. Contact degradation

   1. Vibration

      1. This is when one of the 6 thin gold-plated contacts are worn thin by customer equipment rubbing on the contact pads and creating a connection issue. This can be exacerbated by too tight of a fitting.

   2. Moisture/Corrosion

      1. This is when one of the 6 thin gold-plated contacts are worn thin by customer equipment rubbing on the contact pads and creating a connection issue.

2. Voltage 

   1. This is when the wrong electrical current is applied by customer equipment. That bad voltage setting can damage the microchip inside the eUICC and kill the processor or the memory.

   2. Errant voltage application to the chip can also trigger the anti-tampering detection on an eUICC. Tamper detection is meant to detect and prevent scenarios where the chip and its memory might be physically compromised or hacked. Certain operators require such policies, and in some models like TEAL Industry Edition OneChip, there is a wide selection of operator compatibility that demands such tamper protection.

3. Gold Lead Connectors break

   1. Each plastic eUICC has a very thin gold trace line that connects the gold contacts with the pins on the small ARM chip embedded within the plastic.

   2. This is most common when a device is dropped or suffers a blunt impact. It can also occur when the device is operating outside the intended operating temperatures for the specific SKU. Our standard SIMs are typically between -25 and 85 degrees C, and Industrial grade SIMs are available for -45 to 105 degrees C.

4. Memory corruption

   1. If power is cut to SIM by the device at an inopportune time, or if one of the write operations within the card were to fail (typically beyond the warranty period of many years) there is a small chance that the card memory can be put into an corrupted and irrecoverable state. If that memory block is critical to the function of the SIM, then the SIM can be rendered inoperable.