Temperature RTD’s are widely used in optical systems to control the temperature of lenses and the thermal management of laser modules. The optical systems are often compact while operating at high power levels, which leads to great temperature gradients inside the systems. An optimized optical power output is reached when a good thermal management is achieved along with a precise, reliable temperature measurement, which represents the real capture of the optical components inside the system.  

Temperature RTDs for Lasers


To better detect the temperature of the optical components instead of the various temperature gradients from the system, IST developed a number of specialized products. We provide consulting and support for an optimized placement and usage or our components, helping you reduce the thermal mass and achieve a perfect thermal bond between the sensor and the optical component.  The thermal management is further improved by the complete consideration of the chip's wiring system, as often some of the thermal energy is distributed between the measurement point and carried away through the wire’s terminals attached to the sensors.

Lasers are often used in arrays of smaller laser modules. The more laser modules that are operating simultaneously the higher the output power. Excessive heat created through this array is carried away through a coolant circulation system. The optimized operating temperature is set by controlling the coolant temperature and flow speed going through all the modules. Often a single and considerably bulky flow sensor is in use which allows to control only an average amount of energy spread through the entire system.

Our flow sensors were developed to allow a compact and simplified integration into optical laser modules. This allows to detect the coolant flow speed for each individual module instead of relying on an average temperature among the entire system. The result is better control and an optimized thermal management for each individual module with an overall better output power for the system. The end product efficiency, quality and life and down time is improved.

The world's smallest platinum temperature SMD

Miniaturized bondable RTD designed for DIE package integrations

To enable an integration of an RTD chip in proximity of other electronics and optical components, IST development the smallest RTD chip available in the market. Our motivation was to provide a solution, where long-term stability and good thermal transfer at low cost are important.

The miniaturized RTD is designed for automatic placement in high volume applications in DIE packages and can be packaged and integrated with semiconductor devices, through ball-wedge or wedge-wedge Au-wire bonding.The IST BondSens-Platinum Sensor features a very small size of 0.75mm x 0.75mm which represents a very low thermal mass allowing very precise measurements with lowest influences through the chip itself.

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Temperature sensor with metallized backside

Thermal management through good thermal transfer

The creation of a chip which has the ability to capture its surrounding thermal profile was in mind when the sensor with a metallized back side was developed.

A layer system on the back of the chip enables the possibility to mechanically bond an RTD chip to a metal surface, such as copper or stainless steel, and is often also used in laser modules. The back side of the chip is coated with a gold finish, which allows the use of a low melting point tin (LMP) or high melting point tin (HMP) to bond between sensor chip and metallic surface. Although the sensors with metallized back side can withstand up to 300 °C, the maximum application temperature for LMP is 150°C, whereas the HMP tin sets the boundary for the sensor to operate at up to 250°C.

Most of IST’s products can be ordered with a metallized back side. A large variety of standards are already available, and if your sensor of choice is not yet made with the metal layer on the back, a customized solution can be selected starting at low approval sample quantities to high volume demands.

Out of liquid flow sensor

Detection of coolant flow speed

Flow sensors were development to allow a compact and simple integration into optical laser systems and modules. The compact design allows to integrate small modules and detect the coolant flow speed for each individual section inside an array of modules. The result is better control and an optimized thermal management for each individual module with an overall better output power and an improved product quality and reliability.

The out of liquid flow sensor is a thermal based flow sensor component which consist of a heater and sensor pair. The sensors are sitting outside the flow channel and are not an obstacle to the coolant fluid whereas at the same time there are no concerns about a chemical impact to the sensor chips. The set up allows a customizable measurement flow profile to achieve best measurement performance at the lowest possible costs.