Novel Packaging Techniques

Module and Window solutions

Most of our Silicon Drift Detector Chips are built in special Transistor Outline (TO) packages with closed or open caps. The detector chip is cooled down to temperatures of -20 °C or -30 °C by an integrated 1-stage or 2-stage Peltier cooler. At these temperatures, the optimum detector performance is already reached.

Closed cap detectors use thin external x-ray windows and are encapsulated under vacuum or N2 atmosphere. The X-ray detection efficiency and the protection of the chip from environmental factors such as optical light or moisture are balanced by the careful choice of the module window. A selection of different module windows is listed below.

Planar Thin Windows (PTW)

PNDetector has developed a novel type of X-ray window based on a thin Si3N4 film realized on a silicon frame in a planar process in our own manufacturing line. These so-called Planar Thin Windows (PTW) is the best known and most reliable solution for detection of light elements in the field of microanalysis and X-ray fluorescence analysis. PTWs in combination with our advance “Complete” detector housing technology reduce significantly the risk of humidity, contamination or residual light within the detector housing providing robustness and protection for the sensor on the one side and high quality X-ray analysis on the other side depending on the choice of used window down to Carbon or even Beryllium. This in-house developed technology offers a very flexible and economical solution in terms of available designs and further optimizations.

Three different types of PTWs with optimized light shielding vs. quantum efficiency have been developed and are available for detector sizes up to 100mm²:

The “Complete” SDD Module

For XRF applications in harsh environmental conditions, a completely controllable hermetically sealed package has been developed. It combines the vacuum housing technology including reactivable getter with the continuous monitoring of the pressure of the inner vacuum atmosphere and the temperature of the SDD chip. In the standard configuration the Complete Module is closed with a thin Beryllium Window.