Ford Motor Company Limited

Wells L Green

Stanley R Merchant

Michael J Esper

Charles M Wells

Jay DeAvis Baker

Myron Lemecha

Paul E Stevenson

Bernard A Meyer

Jerry L Springer

Elmer T Heiney, Iii

Richard K McMillan, Ii

Kenneth A Salisbury

Matti Mikkor

Thomas B Merala

A micro soldering apparatus and method comprising a system (10) for attaching an electronic component (12) to a substrate (14). The system (10) comprises a soldering tool (16) including a dispensing orifice assembly (18) for pulsatingly dispensing a controlled quantity of molten solder (19) to a component (12) and substrate (14) so that the component is joined to the substrate (14) mechanically and electrically upon solidification of the molten solder (19). There is no physical contact between the dispensing orifice assembly (18) and joint. The system (10) also includes a controller for the soldering tool (16). The controller functions in response to process control parameters so that the controlled quantity of molten solder (19) is dispensed through a non-oxidizing atmosphere by a pressure pulse applied to the molten solder.

Micro soldering system for electronic components

An improved sensor having a ceramic element that undergoes a change in an electrical characteristic in response to a change in the partial pressure of oxygen in a mixture of gases to which the ceramic element is exposed. Sensors of this type are used to detect the air/fuel ratio of mixtures supplied to internal combustion engines. Prior art sensors are characterized by little change in their respective electrical characteristics at low operating temperatures. A charge transfer material, platinum or platinum/rhodium is applied to the ceramic element to facilitate or make possible the electron transfers required for sensor operation at low temperatures. Platinum/rhodium alloy is the currently preferred charge transfer material. This alloy, which preferably is 90% platinum and 10% rhodium, reduces the minimum temperature of operation for the sensor as taught herein, and it also substantially eliminates vaporization loss of the charge transfer material.

Exhaust gas sensor having porous, metal-impregnated ceramic element

An improved exhaust gas sensor of the type having first and second titania ceramic elements which have electrical resistances varying as a function of both the temperature and the composition of exhaust gases from internal combustion engines to which the elements are exposed. The first and second titania elements are connected in series circuit in the utilization of the sensor and the resistance of the second element over the operating temperature range of the exhaust gas sensor compensates the signal of the first titania element in a manner that produces a desired signal. The desired signal is a result of variation of the second titania element resistance values when exhaust gases cycle between lean-mixture and rich-mixture compositions. The resistance values of the second titania element are intermediate the corresponding resistances of the first titania element over the temperature range. The second titania element is more dense than the first titania element. It has a density in the range from 3.2 g/cm.sup.3 to 3.8 g/cm.sup.3, i.e., between about 76% and 90% of theoretical density.

Exhaust gas sensor having two titania ceramic elements

An improved exhaust gas oxygen sensor of the type adapted for installation in an exhaust conduit of an internal combustion engine. The improved sensor is of the type employing a titania oxygen sensing element responsive to the partial pressure of oxygen in the exhaust gas. A ceramic insulator supports the titania oxygen sensing element and is of improved design. Prior designs have contributed to cold-working of the electrode lead wires connected to the titania oxygen sensing element. The improved insulator design has a pedestal located adjacent the passages in the insulator through which the lead wires pass for the purpose of minimizing cold-working of the lead wires. This aids in preventing fracture of the wires during their use in a feedback fuel control system employing the oxygen sensor.

Ceramic insulator for an exhaust gas oxygen sensor

A stoichiometric air/fuel ratio exhaust gas sensor construction particularly useful with variable resistance partial pressure of oxygen responsive sensor material is disclosed. A generally cylindrical mounting body, formed of corrosion resistant material, is arranged for receipt within the exhaust system of an internal combustion engine and is provided with a two-part ceramic insert member for support of a wafer of variable resistance sensor material. The ceramic insert member is comprised of a first portion having a slotted tip for receipt and support of the wafer of partial pressure of oxygen responsive ceramic sensor material. The ceramic insert member is arranged to position the wafer within a perforated shield member at a remote free end of the cylindrical housing body. The wafer includes a pair of extending high temperature resistant electrical conductors which are received within bores provided therefor in the ceramic insert member. The extending leads are electrically connected, proximate to the interface of the two-part ceramic insert member, to a pair of relatively flexible, electrically low resistance, high temperature resistant extending lead wires which are received within the second portion of the ceramic insert member.

Stoichiometric air/fuel ratio exhaust gas sensor

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Garden City, MI, United States of America

Wells L Green