Motorola Corporation

David W Stevenson

Daniel N Koury, Jr

Howard M Berg

Daniel W Mason

An improved electro-optic transmitter-receiver is provided by arranging a variable light source such as an LED and a photosensitive device, such as a phototransistor, on one or more parts of a substantially flat leadframe. Both the variable light source and photosensitive device face outwardly in the same direction approximately perpendicular to the plane of the package leads. A unitary transparent cover extends over the variable light source and the photosensitive device. A lense is provided over the photosensitive device that does not extend over the variable light source. An NPN phototransistor is desirable for the photosensitive device and is mounted on the central device lead substantially centered under the centrally located lense. When an N-substrate LED is used it is conveniently located on another lead to one side of the lense. The LED may also be located on the same lead as the phototransistor, but not under the lense. Wire bonding is conveniently used to connect the devices to form a three terminal electro-optic transmitter-receiver. It is desirable to have a recess extending into the cover between the LED and the phototransistor to reduce transmission of internally back-scattered light therebetween.

Single package electro-optic transmitter-receiver

A method is provided for low cost assembly of semiconductive optoelectronic devices by hot aligning wide tolerance components. In the hot alignment step, electrical power is applied to the semiconductor to aid in an optical alignment operation.

Hot alignment assembly method for optoelectronic packages

An assembly method is described in which low level light is used to align an optical fiber to the emitting area of an LED. When alignment is achieved, the power dissipated by the LED is increased to gel or partially cure an adhesive, thereby securing the aligned fiber to the LED.

Method for assembling an electro-optical device

A housing for positioning a discrete optoelectronic emitter and a discrete optoelectronic sensor to function as a coupler. The same housing provides the option for either reflective or transmissive mode operation. The discrete devices are removable to permit substitutions of devices having differing characteristics.

Optoelectronic coupler housing

A low cost electro-optical device is disclosed in which a plastic encapsulated, electro-optical semiconductor device is provided with an aperture into which a segment of optical fiber can be inserted. A suitable connector member is also described.

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Mesa, AZ, United States of America

David W Stevenson