Brown, Boveri & Cie Ag

Bbc Brown, Boveri & Company, Limited

Hubert Holick

Franz-Josef Rohr

Alfred Jester

Franz J Rohr

Elmar Mueller

A large area semiconductor disk, wherein in order to be able to connect, for example, by soldering, welding or diffusion-bonding the semiconductor disk with copper disks serving for the heat conduction and for the current supply, a copper tape wound to form a spiral is used to make the connection between the two disks. Transverse slots are etched or punched into the copper tape so that free V-shaped crosspieces are formed on one side. The ends of the cross-pieces are connected with the silicon disk, and measures are taken so that the crosspieces do not connect with each other. The other side of the wound tape is soldered to the copper disk. The radial thermal expansion differences between the copper disk and silicon disks, as well as the axial thermal expansion differences between the silicon disk and the casing, as well as production tolerances in the planeness of the copper and silicon disks are absorbed elastically by the corresponding V-shape of the crosspieces.

Spiral strip brushlike stress buffering power semiconductor contacts

On the two main surfaces of a semiconductor disc of a large diameter, high-performance semiconductor component, there are soldered one bundle each of metal wires. The other ends of the metal wires are soldered to heat dissipating discs. The metal wires, with increasing distance from the center, are of increasing lengths in order to absorb the differences in the thermal expansion of the semiconductor disc and the heat dissipating discs. Metal ring portions and a ceramic housing complete the semiconductorcomponent. A secure and desirable contact of the semiconductor discs is achieved without the application of pressure.

High performance semiconductor component with heat dissipating discs

An electrochemical measuring cell for determining the oxygen content in exhaust gases from internal-combustion engines and combustions having an ion-conducting solid electrolyte with a measuring electrode as a first layer on the solid electrolyte and a reference electrode as a second layer on the solid electrolyte. A third layer coats the first layer measuring electrode and contains a material with a high partial oxygen pressure to obtain a characteristic U=f(.lambda.) which has a small slope in the range of the air number of about 1; a material with a medium partial oxygen pressure to obtain a characteristic with a medium slope; and a material with low partial oxygen pressure to obtain a characteristic with a steep slope.

Electrochemical measuring cell

A probe for an electrochemical oxygen measurement pickup having an oxygen ion-conducting solid electrolyte with electrodes and electrical contact points connected by conductors to the electrodes, in which the probe has an electrochemically active region provided with the electrodes and an electrochemically passive region provided with the contact points as well as with their electrical connections to the electrodes. This minimizes or avoids false readings resulting from temperature gradient and changes in chemical equilibrium.

Probe for an electrochemical oxygen measurement pickup

A method for automatically controlling the air ratio of a combustion process by adjustment of the fuel-air mixture as function of the air number, the air number of the exhaust gas being measured with a sensor which is particularly sensitive at an air number of a given magnitude, and the combustion process operating with an air ratio having an air number of a different magnitude out of the sensitivity range of the sensor which includes extracting a hot exhaust gas stream from a combustion process having an air ratio with an air number out of the given sensitivity range of a sensor changing the amount of air in the exhaust gas stream to provide an auxiliary gas stream having an air number in the sensitivity range of the sensor, measuring the air number of the auxiliary gas stream to detect the difference from the air number of the given magnitude, and controlling the air ratio of the combustion process to maintain the air number of the auxiliary gas stream at the given magnitude, and apparatus for carrying out the foregoing method.

Growing community of inventors

Lampertheim, Germany

Hubert Holick