Infrastructure - Shared Labs

Mocon

The MOCON OX-TRAN Model 2/61 is an oxygen permeation measurement system. Oxygen transmission through plastic foils or packages is analyzed in six independent cells by means of the carrier gas method. Each cell is sealed and consists of two parts which are separated by a plastic sample. One part is flushed with 100 % oxygen or ambient air. The other part is flushed with forming gas which serves as carrier gas. Oxygen which had permeated through the plastic, is transported to an electrochemical sensor responsible for the measurement. Oxygen Transmission Rate (OTR) can be obtained as a function of temperature in a range from 20°C to 65°C and as a function of relative humidity (RH) between 35 % to 100 %. Measurements are performed for plastic foils with a sample area of 10 cm² or plastic packages (like PET bottles). 

Fourier-Transform Infrared Spectrometer

IFS 66/5

The IFS 66/S is a Fourier Transform Infrared Spectrometer for investigation of the composition of gases, liquids and solids. The technique is based on the absorption of IR-radiation and changing the vibrational or rotational state.

This spectrometer has a resolution better than 0.25 cm-1 at a frequency range from 7500 cm-1 to 370 cm-1. The aperture range is from 0.25 up to 12.0 mm with a total of 16 different apertures. The source is a watercooled SiC glowbar for measurements in the NIR. The beamsplitter is a Ge multilayer coating on KBr. The velocity of the mirror allows a scan rate from 0.055 cm/sec up to 10 cm/sec and up to 20 spectra/sec at a resolution of 8 cm-1.  The spectrometer affords the opportunity to measure with an internal detector in the FTIR itself or outside of the spectrometer with an external detector.

This spectrometer allows Step Scan measurements. These are helpful for time resolved spectroscopy of repetitive events with a time resolution between 10 ms up to 5 µs. Also polarization studies, photoluminescence spectroscopy, two dimensional IR spectroscopy and photo induced absorbance spectroscopy are possible.

IFS 55

The IFS 55 is a Fourier Transform Infrared Spectrometer for investigation of the composition of gases, liquids and solids. The technique is based on the absorption of IR-radiation and changing the vibrational or rotational state.

The spectrometer has a resolution of 0.5 cm-1 at a frequency range from 7500 cm-1 to 370 cm-1. It offers 16 scan velocities between 0.1 and 10.1 cm/s and a scan rate up to 20 spectra/sec at a resolution of 8 cm-1. The spectrometer affords the opportunity to measure with an internal detector in the FTIR itself or outside of the spectrometer with an external detector.

Defect diagnostics

In the field of encapsulation of microelectronics or packaging industry the application of plastics is wide spread, due to their cost efficiency and easy processing. Especially, in packaging industry polyethylene terephthalate (PET) and polypropylene are the dominating material. Nevertheless, plastics offer only limited barrier performance against permeation of gases, e.g. oxygen or CO2. A significant increase of barrier performance can be achieved by the deposition of thin inorganic films by means plasma processes. However, these kind of plasma coatings contain microscopic defects which limit the resulting barrier performance. Usually, these kind of defects are not visible with optical or electron microscopy. Hence, visualization of defects is applied by reactive oxygen etching. This is based on etching the polymer surface underneath coating defects by reactive oxygen species and subsequent imaging with SEM. Most organic polymers like PET are sensitive towards etching by reactive oxygen species. In contrast to this, most inorganic materials like SiOx and TiO2 are almost chemically inert with respect to reactive oxygen species and therefore, etch rates are typically below detection limit. Hence, the inorganic barrier coating serves as a mask against etching and protects the polymer beneath. Nevertheless, reactive oxygen species like atomic oxygen can enter defects and etch the unmasked polymer surface at defect sites. Due to scattering of atomic oxygen in the gas phase etching occurs nearly isotropic, resulting in undercutting of the barrier coating. Subsequently, a crater-like structure is formed. In SEM images, this structure appears as a dark spot in the center surrounded by a whitish circular ring. The dark spot represents the defect, i.e. hole in the barrier film. The number of defects and associated defect density are then determined by an automatized image recognition software, based on the image processing toolbox in MATLAB.