Many are hoping the iPhone 6 will come with significant upgrades, but it sounds like a better Touch ID fingerprint sensor won’t be one of them. A report from DigiTimes indicates that TSMC was looking into using 12-inch processing methods for the fingerprint sensor, but problems will keep that upgrade from making it into the iPhone 6.

iPhone 6 touch id sensor

iPhone 6 to keep 8-inch wafer-level packaging

The iPhone 5S utilizes 8-inch wafer-level packaging, and Apple was apparently wanting to shift up to 12 inches. However, yield problems were said to have caused Apple to go back to the same processing method used for the Touch ID sensor in the iPhone 5S. Using the same method will reportedly provide “mature yield rates” for Apple and TSMC.

Currently yield rates for the sensor are reported to be over 95%, which means Apple seems to have solved the early problems it faced last year when the iPhone 5S went into production. However, yield rates for 12-inch process were reported to be just 70% to 80%, indicating that more work must be done there.

There are a few reasons Apple fans are hoping for a better Touch ID sensor in the iPhone 6. First, the technology limits the usefulness of the sensor to simply unlocking the device. Analysts would like to see the sensor be used for mobile payments, but it doesn’t sound like that will be possible with the iPhone 6. In addition, many iPhone 5S users have reported continual problems with the fingerprint sensor, saying that it just doesn’t work very well.

iPhone 6 probably won’t get sapphire screen

We’ve also been hearing numerous rumors about whether the iPhone 6 will receive a sapphire glass display. One of the more recent reports suggested that it would indeed get a sapphire screen, but a new report today indicates that Apple is actually planning to use the sapphire glass in the smaller iWatch rather than the iPhone 6. The company reportedly couldn’t find a way to use the glass in the iPhone 6 without significantly raising the price of the handset, so instead, it decided to simply find another use for the glass.