Industrial Grade Wireless Wafer Temperature Sensor – RTD Sensors


This unique Leap wireless sensor attaches to the top of a silicon wafer for fabrication process monitoring. It is less than 5mm thick, so it fits in wafer processing ovens and other critical fab equipment. The sensor has 9 ultra-small, high-accuracy RTD sensors that are adhered to the surface of the wafer, giving you better accuracy than a wireless thermocouple wafer sensor (tc wafer sensor).

  • 3-wire RTD connection supports long cables while maintaining temperature accuracy during rapid heating.
  • The entire sensor is rated to operate up to at least 125C (257F).
  • Readings as fast as every 3 seconds for each of the 9 sensors.
  • Field replaceable batteries.
  • Data logging capability when the transceiver node is not linked to a gateway.

This wireless sensor is ideal for monitoring:

  • Silicon wafer processing
  • Temperature chuck testing/verification
  • Scientific experiments
  • Paint and coatings curing
  • Temperature profiling over a surface



Part of the breakthrough Leap Sensors® system.


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Leap Sensors are specially designed to easily adapt to your specifc needs. If this isn’t exactly what you need, please contact us.

Wireless Wafer Temperature Sensor Specifications

This highly versatile industrial sensor supports 9 miniature, low-mass precision RTD temperature sensors connected to one small, thin high-temperature transmitter.

Designed Specifically for Silicon Wafer Processing Applications

  • High-value ROI: Especially for a wafer sensor that can be maintained and last a long time.
  • Less than 5mm thick: Electronics, battery, and all other components are designed to fit in a standard fab oven and other wafer processing equipment.  Optional silicon sheet insulator between the wafer and electronics adds 0.75mm.
  • Circuit board size: 1.45 x  2.20 in inches, 37 x 56mm.
  • High temperature: Electronics and battery operate continuously up to 125C (257F).  Contact us for higher operating temperature options.
  • Rapid temperature sampling rate: Each of the 9 sensors can be read every 2 seconds.
  • Real-time data: Wireless transmitter and onboard antenna can send updates every 15 seconds – even when the wafer is in a closed oven.
  • Data logging (when needed): If the sensor loses communication with the gateway, the sensor writes the time-stamped data to memory.
  • Splash-proof: Electronics do not have an enclosure, but they may be conformal coated make them splash-resistant.
  • Full wafer coverage with 9 sensors: Sensors are typically placed 4 along the edge, 4 in the middle, and 1 in the center.
    • Customized sensor placement – Let us know if you want your sensors located in different places. We will ship the wafer to you “ready to go”.
    • Available on all wafer sizes. (200 mm wafer is shown in the photo). Contact us with your needs.
  • Optional silicone backing: The circuit board and batteries can be backed with a thin silicone sheet to reduce heat transfer into these components. This adds 0.75mm to the 5mm maximum height.
  • High accuracy RTD temperature sensors – Class A sensors for high accuracy.
  • Miniature RTD Temperature Sensors – low mass and fast response.
    • Adheres to wafer with epoxy. Can be replaced if needed.
  • Replaceable batteries – long sensor life.
    • Field replaceable batteries – takes less than 1 minute.
    • Standard replacement batteries can be ordered off the internet.
  • Easily repairable – assures your investment.
    • If a component gets damaged, contact us for a quick repair.

RTD Specifications

  •  Low mass:
    • Utilizes Omega Class A F Series sensor.
      • Thin-film DIN Class A.
      • Size: 2.3 x 2.1 x 0.9 (thick) mm.
      • Rated for temperatures between -50 and 500°C (-58 to 432°F). However, Class A accuracy is assured between -30 to 300°C (-22 to 572°F).
  • 3-wire RTD:  the sensor utilizes a 3-wire configuration to the RTD sensors. The electronics measure and compensate for changes in wire resistance over temperature changes.
  • Long cable lengths to sensors:  The 3-wire RTD temperature sensor design facilitates long cable lengths to the sensors (if needed) while maintaining temperature accuracy.
  • Temperature accuracy:
    • Contact us for application-specific estimates on accuracy.
    • Typical: +/- 0.4C from 25C to 120C.
    • High-accuracy version: +/- 0.1C, or better (over specified temperature span) is available. Contact us for details.
  • Sensors connect to main circuit board with wire soldered to the sensor and to the three thru-holes on the circuit board.
  • Other RTDs can be connected to this board. Contact us for more information.

Sensor Electronics and Battery

  • Small, thin electronics board:
    • 2.2 X 1.5 inches.
    • Less than 5mm thick.
  • Electronics operating temperature: 
    • Standard operating temperature: Battery and electronics can operate up to 125C, or higher*.  
    • *Higher operating temperatures are available – contact us.
  • Optional additional on-circuit-board temperature sensor
    • 3-Wire RTD – electronics measure wire resistance to the sensor and compensate for changes in wire resistance over temperature to maintain accuracy over a wide temperature range.
  • Fast temperature sampling time interval:
    • Fastest sampling rate for 9-RTD temperature sensors – all 9 sensors every 3 seconds.
      • Data is typically data-logged with a time stamp on the sensor, then transmitted every 15 to 30 seconds.
    • Sampling options as slow as one sensor reading per day.
  • Data logging: Sensor will act as a data logger, storing up to 10,000 time-stamped readings on-board, when a gateway is not in range. See details below.

Leap Wireless Sensor Transceiver Node Specifications

  • Transmission distance to a gateway – typically 200 feet in open air. The sensor transmitter antenna is on the circuit board.
  • 2-way communication with the sensor through the user interface:
    • Name the sensor, set sensor sampling time interval, set wireless transmit time interval, over-the-air firmware updates.
    • Gateways send an acknowledgment to the sensor that the data was received for high reliability.
  • Sensor data logging – When sensors do not receive an acknowledgment from the gateway that the radio transmission was received, the Leap Sensor will store the time-stamped data on-board until the gateway connection is established.
  • Reliable industrial over-the-air radio communication
    • Industry-standard 802.15.4 with Direct Sequence Spread Spectrum (DSSS).
    • Gateway “hand-shake” acknowledgments of successful transmission and sensor data logging for extra reliability.
  • Over-the-air protocol – Standard and established 6LoPan and Thread.
  • Data security – AES encryption.  Standard and established TLS security.
  • FCC certified.
  • Battery – user-replaceable 3.0C or 3.6V batteries.

Leap Wireless Sensors Gateway (Receiver) and User Interface Software

  • See the Leap Sensors gateway page and the Leap Sensors User Interface options page for more detailed information.
  • Leap Sensors wirelessly transmit data to a gateway*.
    • Gateway can support over 250 sensors that are in range. (Additional gateways can extend sensor coverage.)
    • The gateway then passes the data to the Leap user interface software. The user interface software may be hosted on the gateway (and connected to a PC with a USB cable), on the password-protected Leap Sensors Cloud web site, or an on-site server.
  • User interface supports: logging-in, set user rights, view sensor data, set email and text alerts (cloud version), graph sensor data, download data to excel, add or subtract sensors, update firmware, and other functions.

*Custom-ordered leap sensors are available with a direct-to-cellular option where no gateway is needed and the data is sent directly to a cloud server. Contact us for more information.

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