High conductivity copper

Numerous variations exist in the electroless plating solutions, processes, and techniques employed both in laboratory and commercial form, to create a great variety of products (39). AH produce a layer of highly conductive copper in specified areas. Modem electroless copper films have a ductiHty and conductivity identical to that of electrolytic copper (40). The three basic classes of copper baths are... 

Figure 3.5. Eflett of temperature on the tensile strength of copper (A) effect of annealing on strength and ductility (B) hardened high-conductivity copper 129. ...

The TMoio microwave cavity design is very simple, consisting of a cylindrical hollow cut into a block of oxygen-free high-conductance copper, with an end-cap to form a lid. The TMoio mode has axial electric field with an antinode on the axis of the cylinder. Beam holes on axis thus allow the 2Si/2 ions to pass through the highest electric field, which quenches them. The mode frequency, which depends on the cavity radius, is set to the Lamb shift frequency of 14.04 GHz. We... 

The detector consisted of a Wheatstone network of capillary tubes that were drilled out of a high conductivity copper block and was fairly compact. The reference flow of mobile phase and the eluent from the column entered at two opposing junctions of the bridge arms (the center of tube (C)) such that the eluent was contained in one vertical arm (C) and the pure mobile phase in a parallel vertical arms (A) and (B). The increase in pressure at the base of tube (C) due to the presence of solute in (C) applied a pressure to the bottom of tube (A). This caused a flow of gas through the anemometer from tube (A) to tube (B) providing an output that was fed to a recording milliammeter. Subsequently all flows exited from the top and bottom of tube (C). 

The objective of this research work is to develop a highly conductive copper alloy based diffusion barrier for copper metallization. The criteria for selection was that minimal increase in resistivity resulted on addition of one atomic percent of second element to copper. The copper-1 at.% zinc alloy conforms to this criteria and hence was selected as a candidate material for further study. Pure copper can easily be electroplated from simple acid copper baths, but the alloys of copper are more difficult when the deposition potential of individual elements is widely separated as in the present case. A Cu-Zn alloy can be deposited from baths containing coordinating agents. Having established that a Cu-Zn alloy can be successfully electroplated, an alloy of composition Cu-3.5%Zn was sputter deposited to develop an MOS capacitor and electrical testing was performed on as-sputtered and annealed samples. The bias temperature stability tests indicate that the alloy possesses promising diffusion barrier properties. 

The damper bars or winding act in a manner very similar to an induction motor and provide a breaking torque against the transient disturbances in shaft speed. To be effective the damper needs to have a steep torque versus shp characteristic in the region near synchronous speed. The equivalent impedance of the damper requires a low resistance and a high reactance. High conductivity copper bars are embedded into the pole face to provide a low reluctance path for the leakage flux. 

Copper and aluminium are used in their highly refined form for the power conductors of cables. The total impurities contained in high conductivity copper should be less than 0.1% and for aluminium less than 0.5%. The measured conductivity of these metals will have its highest value when they are annealed. Hard drawn conductors will have conductivity that is several percentage points lower than the annealed value. Note that castings made of these materials will generally have conductivity slightly lower than their rolled and drawn forms. 

The electrons emitted by the photocathode are subsequently accelerated to 50 kV and focused on to a toroid-shaped anode. The anode is made of oxygen-free, high conductivity copper and is maintained at a high positive potential. The electron pulses interact with the copper anode forcing the emission of Cu-Ka x-ray photon pulses, which exit the vacuum chamber through a thin beryllium-foil window. A bend germanium crystal monochromator disperses and focuses the x-rays onto the sample. The duration of the x-ray pulses is measured by a Kentech x-ray streak camera fitted with a low density Csl photocathode. The pulse width of the x-rays at 50 kV anode-cathode potential difference is about 50 ps. This value is an upper limit for the width of the x-ray pulses because the transit time-spread of the streak camera has to be taken into consideration. A gold photocathode (100 A Au on 1000 A peiylene) is used to record the 266-nm excitation laser pulses. The intensity of the x-rays is 6.2 x 10 photons an r (per pulse), and is measured by means of a silicon diode array x-ray detector which has a known quantum efficiency of 0.79 for 8 kV photons. 

Past experience indicates that for a high-conductivity copper matrix, interfacial resistance is usually important, but for a copper alloy matrix, it is not important. Since, in this experiment, a copper matrix was used, model 2 presumably applies, even for a short sample. 

High conductivity coppers These are used mainly for their high electrical and thermal conductivities. Applications include tuyeres for blast furnaces and hot blast cupolas, water-cooled electrode clamps, switchgear, etc. 

It is possible to prepare, in the two-phase domain, composite alloys consisting of a high conductivity copper rich phase and a low expansivity Invar rich phase [1998Cot] provided that the ratio Fe/Ni be maintained near by 64/36 (in mass%) because the Invar effect occurs only in a narrow composition range. 

Pure or elemental copper, also known as oxygen-free high-conductivity copper (OFHC), has a low annealing point. When annealed, the mechanical... 

MECHANICAL AND PHYSICAL PROPERTIES OF HIGH STRENGTH, HIGH CONDUCTIVITY COPPER-NICKEL-SILICON-CHROME FOR MOLD TOOLING... 

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