Measuring surface temperature without touching - is it possible?

Sometimes it is not possible to buy the technical product you need "in town". This applies not least to technical measurement systems. At the same time, it is important to make rapid progress on projects in order to get products on the market as quickly as possible. So what do you do if you need to buy something that doesn't exist? Well, you turn to Infotiv, of course!

- Now we have a customer in power electronics who needs a fast measurement system. The system is based on non-contact, in order to be able to measure temperature with high precision in short-circuited bipolar transistors with an insulated gate (IGBT)," says Majid Samani, who also designed the solution for the customer and is about to make the final delivery.

PROJECTS FROM START TO FINISH

This is a project from start to finish. The task was to design, build and deliver a measurement system that uses the photothermal effect to measure temperature at the nano- and microsecond level. But what exactly is the photothermal effect? And how does the measurement work in practice? Majid explains.

- Most materials have a temperature-dependent refractive index. When a surface is heated, its refractive index changes. By changing the refractive index, its reflectance changes as the temperature changes. Therefore, the relative change in reflectance is linked to the change in temperature and we call these phenomena the photothermal effect.

MEASURES THE SURFACE TEMPERATURE WITHOUT TOUCHING IT

Photothermal temperature measurement is a non-contact optical method where the surface temperature of a material is measured by reading the intensity of the focus of a reflected laser beam. The temperature profile is measured as a function of time at the nano- and microsecond level.

- The structure is designed to use high-precision optics to read the temperature of electronic devices with a response time of 7 nanoseconds and a spatial resolution of micrometers. It consists of about 50 different optical and optomechanical components, which are separable and were also purchased separately for assembly," says Majid.

BENEFITS OF THE TECHNOLOGY

Commercial temperature measurement systems, such as thermocouples, IR cameras or fiber optic temperature meters, cannot measure temperatures at the nano- and microsecond level due to slow update times. Majid explains:

- Infotiv's design for temperature measurement is thus an optical system, based on non-contact. With a response time of about 7 nanoseconds, the system can read a temperature profile very quickly.

HOW TO USE THE SYSTEM

The system is essential for engineers and scientists working on temperature measurement in electronic equipment in both industrial companies and research institutes.

- The system is crucial because it allows you to quickly create a temperature profile for electronic structures and to optimize design, material selection, lifespan, as well as temperature management and thermal stress in a shorter period of time.