Showing papers on "Tantalum capacitor published in 1986"

Photo-CVD of Tantalum Oxide Film from Pentamethoxy Tantalum for VLSI Dynamic Memories

Abstract: Recent VLSI requires materials with high dielectric constant in order to reduce their storage capacitor areas. We attempted to form a tantalum oxide film from Ta(OCH3)5 at a low temperature by photo-CVD method. Our evaluation shows that the photo-CVD film obtained in this study has good step coverage, high dielectric constant (20–24), and low leakage current, and is superior to the thermal-CVD film in various characteristics.

Tantalum capacitor lead wire

Abstract: A tantalum lead wire for capacitors having improved grain growth characteristics is disclosed. The lead preferably comprises a Niobium core having a surface consisting of many discrete layers of Tantalum surrounding the Niobium.

Solid electrolyte chip capacitor method

Abstract: A solid-electrolyte chip capacitor of improved volume efficiency and placement capability is attained by molding a solid-electrolyte capacitor section so that the cathode end of the capacitor section is not covered by the molding material, and the anode end of the molding is provided with a recess within which the riser from the anode of the capacitor section is accessible.

Integrated capacitor and method of fabricating same

Abstract: An integrated capacitor having an oxide layer of less than 500 Å as a dielectric or insulator. A method of fabricating a capacitor including the steps of forming an oxide layer on a substrate, forming through the oxide layer a first capacitor plate in the substrate, and forming a second capacitor plate on the oxide layer. The method also includes the step of restructuring the oxide layer after the step of forming the first capacitor plate. Since the first capacitor plate is formed through the oxide layer the oxide layer can be grown on an undoped or lightly doped substrate; thus, the effects of the doping level on the growth rate of the oxide layer are eliminated and oxide layers having a uniform thickness of less than 500 Å can consistently be provided.

Non-aqueous liquid electrolyte for electrolytic capacitors and electrolytic capacitors using same

Abstract: Non-aqueous liquid electrolytes for electrolytic capacitors which comprise diazobicyclealkenes and/or salts thereof as a solute. The electrolytes are effective in improving low temperature and high temperature characteristics when applied as electrolytic capacitors. The capacitors using the electrolytes are also described.

Surge Current Failure in Solid Electrolyte Tantalum Capacitors

Abstract: Fast charging and discharging of solid tantalum capacitors causes breakdown by heating in the MuO 2 cathode instead of dielectric breakdown. It appears that localized regions of lower resistance and poor thermal contact to a heat sink allow very high temperatures to occur. These "hot spots" can then cause breakdown of the adjacent dielectric film and, eventually, loss of the capacitor. Temperature increases are detected by measuring the change of resistance of the MuO 2 cathode and by their effect on temperature sensitive paint. The hot spots tend to concentrate near the surface of the anode at the upper and lower shoulders. The heating effect of leakage current is negligible for these tests.

Welding current control circuit for spot welder

Abstract: In a spot welder in which the electric charge stored in an electrolytic capacitor (1a) is discharged through a welding circuit 3 to perform a welding operation, in order to prevent the lowering of the welding performance due to the inversion in polarity of the voltage of the electrolytic capacitor (1a), its main circuit includes another electrolytic capacitor (1b) which is connected in series to a DC source (5) and shunted by a resistor (7) and which is substantially equal in capacitance to the aforementioned electrolytic capacitor (1a), and after the electrolytic capacitor (1a) only is charged, a switch (2) is turned on so that the charge current of the electrolytic capacitor (1a) is discharged to charge the electrolytic capacitor (1b), whereby charging the electrolytic capacitors (1a) and (1b) in opposite directions is prevented.

Study of rapidly quenched Al-Ti alloys for electrolytic capacitor electrodes

Abstract: To improve an electrical capability of aluminum electrolytic capacitor, a new electrode material of large dielectric constant and high dielectric strength. This thin film electrode of titanium rich aluminum alloy is made with a rapid quench method and has very small grain size of a few micrometers and high toughness. Al-Ti alloy capacitors of this thin film show CV value of 1.5 times as large as an uptodate aluminum capacitor. Characteristics of chemical formation and etching of the Al-Ti alloy electrode is referred.

Method of forming a solid tantalum capacitor

Abstract: The dielectric stability of a hermetically-sealed solid-electrolyte tantalum capacitor during high temperature storage is improved by the introduction of a small controlled amount of water into the capacitor container before the final sealing step in the manufacture of the capacitor.

The Preparation and Properties of 4.7 uF 2220 Size 50 V Z5U Relaxor Multilayer Ceramic Capacitors

Abstract: A new dielectric for multilayer ceramic capacitors is currently undergoing factory qualification. This dielectric is based on a nonstoichiometric lead magnesium niobate relaxor material. Dielectric constants in excess of 15000 have been achieved for bodies which sinter close to 900°C with 100 percent Ag internal electrodes. The use of very high Ag content electrode systems means that there is a considerable cost reduction so that multilayer ceramic chip capacitors become cost competitive with solid tantalum chip capacitors. The preparation and properties of the dielectric material are described and life test data are presented showing that capacitors of the new dielectric are extremely stable for periods up to two years at ambient and upper rated temperature. A direct comparison is made between the electrical properties of 4.7 uF 50 V 2220 size Z5U multilayer chip capacitors manufactured from the new relaxor dielectric and the equivalent value tantalum chip capacitors.

Electrical element such as a tantalum and solid-electrolyte capacitor

Abstract: Solid electrolyte capacitor wherein the anode end-fitting is constituted by a massive metallic element having sufficient thermal inertia to compensate for the difference in melting temperature of the materials constituting the anode end-fitting and the anode wire.

A trench-incorporated monolithic semiconductor capacitor and high density dynamic memory cells including the capacitor

Abstract: A high density integrated circuit structure, for example a dynamic memory cell, is described which includes an active/passive device in combination with a capacitor structure. The capacitor structure is of the polysilicon-oxide-silicon type and is formed on the sidewalls of a mesa-shaped and dielectrically isolated region of silicon material resulting from the formation of an isolation trench in the silicon. The trench is filled with a plastic material, such as polyimide. The capacitor is formed by the isolated region of silicon material (14) which functions as the first capacitor plate, a doped polysilicon layer (22a) provided on the vertical walls of the mesa serving as the second capacitor plate and a thin dielectric layer (21) interposed between the two plates serving as the capacitor's dielectric. Since the poly­silicon is wrapped around the periphery of the mesa as a coating on the vertical sidewalls thereof, it gives rise to a large storage capacitance without an increase in the cell size.

Shelf-Life Evaluation of Aluminuin Electrdytic Capacitcirs

Abstract: .ECENT IMPROVEMENTS in the design and manufacturing processes of modern aluminum electrolytic. capacitors, plus their cost effectiveness when compared to tantalum capacitors is resulting in an increased evaluation of these components for applications in the design of electronic circuits. The use of these capacitors in lowvoltage circuitry (l-2 V dc) which are powered in a noncontinuous manner (such as electrotiic telephones) requires special attention since performance characteristics for extended operation under these coriditions are generally not available. The circuit designer requires knowledge of the effbcts of these operating condi&ons on capacitance value, leakage, current, and effective series resistance (ESR). Measurement of these characteristics before and after an accelerated shelf-life aging test was considered to be an effective method of predicting their actual operating performance. The purpose of: the work reported here tias to determine the suitability of aluminuni electrolytic capacitors for use in lowvoltage electronic circuit applications by using an accelerated shelf-life aging test as a simulation method. A total of 180 capacitors from four different tianufacturers (vendors A, B, C, and D) were tested, and the results are presented. The significance of the results will be discussed along with application guidelines for the use of these components in lowvoltage circuits. II.