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ABSTRACT: High resistance thin film chip resistors (0603 type) were studied, and the specifications are as follows: 1 kΩ with tolerance
about ±0.1% after laser trimming and temperature coefficient of resistance (TCR) less than ±15×10−6/°C. Cr-Si-Ta-Al films were prepared with Ar flow rate and sputtering power fixed at 20 standard-state cubic centimeter per
minute (sccm) and 100 W, respectively. The experiment shows that the electrical properties of Cr-Si-Ta-Al deposition films
can meet the specification requirements of 0603 type thin film chip resistors when the deposition time was about 11 min and
deposition films were annealed at 500 °C for 120 min. The morphologies of Cr-Si-Ta-Al film surfaces were examined by scanning
electron microscopy (SEM). The analysis suggests that Ta and Al may be distributed in CrSi2 film with mixed form of several structures (e.g., bridge-like, capillary-like or island-like structures), and such a structure
distribution is responsible for high film resistance and low TCR of Cr-Si-Ta-Al film.
Keywordsthin film chip resistor-high resistance-low temperature coefficient of resistance-alloy target-magnetic sputtering-Cr-Si-Ta-Al film
Transactions of Tianjin University 04/2012; 16(5):348-353.
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ABSTRACT: Second toe-to-thumb transfer is a good alternative to using the great toe for reconstruction of the thumb. It achieves excellent function and reduces morbidity to the donor foot. However, cosmesis is often poor. The second toe has three unattractive features, a narrow "neck," a bulbous tip, and a short nail.
The authors describe a modified second toe transfer that addresses cosmesis in six patients. These include (1) harvesting a flap from the adjacent side of the great toe and insetting it into the volar aspect of the second toe to give more bulk, (2) making skin excisions on each side of the tip to reduce the bulbous appearance, and (3) excising the eponychium to produce apparent lengthening of the nail.
The mean follow-up period was 18 months (range, 6 to 36 months). The procedure resulted in good function and improved cosmesis in all six cases. Part of the great toe flap was lost in one case. The mean two-point discrimination in the transferred toes was 10.1 mm, with protective sensation present in the flaps. The range of motion of the transferred toe was 14 to 38 degrees at the metatarsophalangeal joint, 16 to 55 degrees at the proximal interphalangeal joints, and 20 to 36 degrees in the distal interphalangeal joints. All patients except one were happy with the appearance of the transferred toe.
This novel approach will allow patients to take advantage of the lower morbidity to the donor site afforded by second toe-to-thumb transfer and provide the patients with a more aesthetic appearance of the new thumb.
Plastic and reconstructive surgery 12/2010; 126(6):2052-9. · 2.74 Impact Factor
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ABSTRACT: A kind of new silver paste with silver content about 50wt%, nano-silver paste, significantly different with normal silver paste in roasting temperature, was prepared using nano-silver powder, ethanol, n-butyl alcohol, n-hexyl alcohol and low polymer fibre. The nano-silver paste shows weight loss and volatilization with different levels on thermogravimetric (TG) analyzing curve. Field emission scanning electron microscope (FESEM) analysis indicates when roasting temperature is controlled at 200°C, the surface of finished silver film has already been compact and smooth. And finished silver film has stronger adhesive with ceramic and mental substrates, while the adhesive is poor with slippery glass. The minimal square resistor of obtained silver film can reach 7.8mΩ/□.
Electronic Packaging Technology, 2005 6th International Conference on;
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ABSTRACT: Epoxy resin undercoat, with high temperature and humidity resistance, for resistor was prepared by curing of acid anhydride and accelerating of glycol with proper nano-SiO<sub>2</sub> added at 80°C. The properties of undercoat prepared were characterized by electrical tests, infrared spectra (IR), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). The results showed more compact and steady inter-crosslinked network structure was formed in the modified epoxy resins undercoat with nano-SiO<sub>2</sub> added, which leaded to the performance of modified epoxy resin undercoat improved greatly. The undercoat with nano-SiO<sub>2</sub> 2.68wt%, kept for six months at room temperature without flocculating and aggregating, is of good stability. The varying ratio of resistance with such undercoat painted is less than 1% after high temperature and humidity resistance test. In this work, an attempt has been made to prepare undercoat, with high temperature and humidity resistance, for resistor by modifying epoxy resin using nano-SiO<sub>2</sub>.
Electronic Packaging Technology, 2005 6th International Conference on;
