Thermal Imaging

bsw is a partner of Microsanj – one of the technology leaders in the area of temperature measurements on extremely small surfaces.

The systems are used in research institutes as well as in industrial applications...

  • for evaluating temperature distribution
  • for validating models of thermal designs and the efficiency of heat sinks
  • for problem resolution, e.g. when hotspots occur
  • for characterizing static as well as time/transient thermal effects.

One of the biggest challenges during the ongoing miniaturization of integrated circuits is heat generation under operating conditions. An important step in order to improve designs and layouts is the investigation of the chip's thermal characteristics and temperature distribution. There are several methods for measuring the temperature of micron and sub-micron chips. The most widely used method is infrared thermography.

However, a far better resolution can be achieved with thermography using Thermoreflectance Imaging.

This method uses the changing reflectance of materials which is caused by temperature changes. A light source illuminates the measurement area, and the temperature change is calculated from the light that is reflected by the DUT.

Not only is the hardware setup and control fundamentally different with this method, but the processing and evaluation of the acquired images is also of vital importance. The Microsanj SanjVIEW 2.0 software package with the SanjANALYZER offers multiple intuitive methods for these tasks.

Advantages of TTI

Temporal resolution:

The Thermoreflectance Thermal Imaging method offers the highest available temporal resolution for temperature measurements in full-field images. The commercial Microsanj system NT210A / NT310A achieves 100ns in a megapixel image; the latest system, NT410A even achieves a resolution of 800ps.

The full-field resolution of IR systems is limited by the frame rate, which lies in the area of tenths of milliseconds. For low-resolution images, an IR camera can achieve 1ms if pixel binning (consolidation of several pixels) is used during evaluation of the image.

Spatial resolution:

The spatial resolution of the Thermoreflectance Thermal Imaging method is limited by the diffraction of light; it is 300-600nm if illumination with wavelengths in the visible spectrum is used, and 1 micron if illumination near the IR spectrum is used – this is close to an illumination wavelength of 1.0-1.5 microns, which is used by through-the-substrate systems. Compared to IR microscopes which are based on INSB, this spatial resolution is better by a factor of 3-10.