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Low Temperature Co-fired Ceramics (LTCC) have excellent high-frequency characteristics and have widely been used for microwave electronic components. By lowering the sintering temperature of the ceramics used as insulating layers, LTCC was co-fired with a high-conductivity wiring conductor, such as Cu or Ag. LTCC substrate has been expected as one of the most promising technologies to realize miniaturization of RF circuits in the field of wireless communications. There is no limitation to demand for further downsizing of RF circuits, suppression of electric loss and high mechanical strength of the substrate. However, conventional LTCC materials for substrates contain glass frit which causes defects, such as pores or cracks, and low mechanical strength. In this work, we have developed a novel LTCC material system BaO-Al2O3-SiO2-MnO-TiO2, without any glass frits. The material was co-fired with cupper electrodes, which have low resistivity and show less diffusion than silver in LTCC, under a low-oxygen partial pressure atmosphere (mixture of N2 and H2) at 980°C. Thin layers (8μm) of the material showed high insulating resistivity and reliability due to few defects, such as pores, in LTCC. Its dielectric and mechanical properties were measured as 6.8 (low-εr), 350 at 3GHz (high-Q-value) and 341MPa (high mechanical strength) respectively. This LTCC material will contribute to further miniaturizing of microwave applications and integration of passive elements.

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Headaches often occur after a lumbar puncture, and it is considered to be caused by cerebrospinal fluid leakage from the puncture site. A 24-year-old woman presented to our hospital with a headache and fever and underwent a lumbar puncture to investigate meningitis. She complained of severe headache and back pain after the procedure. Here, we report a case of extensive cerebrospinal fluid retention in the thoracic epidural space confirmed through magnetic resonance imaging (MRI) . A 24-year-old woman with fever(body temperature, approximately 39℃)and headache presented to our hospital and was admitted to the neurosurgery outpatient clinic for the diagnosis of meningitis. Lumbar puncture was performed using a 22-G spinal needle. The cerebrospinal fluid was drained in one puncture, and approximately 5 ml of cerebrospinal fluid was collected. The procedure ended without complications. However, she had severe orthostatic headache and back pain the next day；therefore head MRI and spinal MRI were performed. Head MRI showed mild-enhancement of the dura mater, whereas spinal cord MRI showed a large amount of cerebrospinal fluid retention at the dorsal epidural area of the spinal cord in the thoracic spine but not in the lumbar spine. Her symptoms improved with infusion and rest alone, and a blood patch was not necessary. Two weeks later, MRI was performed, and it was confirmed that cerebrospinal fluid retention had resolved. After the lumbar puncture, MRI of the area surrounding the puncture site, as well as the cervical and thoracic vertebrae, is useful for diagnosing cases of cerebrospinal leakage.