• Journal of the Korean Society of Radiology
• /
• v.8 no.7
• /
• pp.371-376
• /
• 2014

The process of flip-chip bump bonding, Au wire bonding and encapsulation were sucessfully developed and modularized. The CdTe sensor and ROIC were optimally jointed together at $150^{\circ}C$ and $270^{\circ}C$ respectively under24.5 N for 30s. To make SnAg bump on ROIC easy to be bonded, the higher bonding temperature was established than CdTe sensor's. In addition, the bonding pressure was lowered minimally because CdTe Sensor is easier to break than Si Sensor. CdTe multi-energy sensor module observed were no electrical failures in the joints using developed flip chip bump bonding and Au wire bonding process. As a result of measurement, shearing force was $2.45kgf/mm^2$ and, it is enough bonding force against threshold force, $2kgf/mm^2s$.

• Journal of the Korean Society of Radiology
• /
• v.9 no.7
• /
• pp.439-443
• /
• 2015

An electrical signals of a conventional radiation medical imaging sensor are obtained by charge integration method. In this study, the polycrystalline cadmium telluride(p-CdTe) film was fabricated by a thermal evaporation method for the photon counting sensor development with excellent resolution in low exposure dose. From the fabricated p-CdTe sensor, the physical properties(SEM, XRD) and the electrical properties(leakage current, x-ray sensitivity, SNR) were evaluated. As a result, the leakage current of below $5nA/cm^2$ and $7{\mu}C/cm^2-R$ of the X-ray sensitivity were showed in below $1V/{\mu}m$. In addition, the signal to noise ratio showed the values of above 5000 at operating voltage.

• Journal of the Korean Society of Radiology
• /
• v.3 no.4
• /
• pp.29-33
• /
• 2009

Recently, the compound materials(a-Se, $HgI_2$, PbO, CdTe, $PbI_2$, etc.) that are used in flat panel x-ray imager have been studied for digital x-ray imaging. In this paper, the signal detection properties of $HgI_2$ and a-Se conversion layer, are compared. The thick $HgI_2$ film is fabricated by special particle-in-binder method and the conventional vacuum thermal evaporation is used for a deposition of a-Se film. And an electrical characteristic measurements were investigated about leakage current, signal response property and x-ray sensitivity. From the experimental results show that the $HgI_2$ film has a low operation voltage and high signal generation than that of a-Se.