Northern Telecom Limited

Tibor F Kovats

Jozef Straus

Christopher M Look

Tibor F Devenyi

William J Sinclair

Anthony J Springthorpe

John C Dyment

Isabella C Bassignana

A method and apparatus for use in performing non-contact analytical evaluation of a semiconductor wafer, which needs to be kept clean, to be performed outside of clean room facilities. The apparatus maintains a clean environment surrounding the semiconductor wafer and a portion of the apparatus is substantially transparent to a probe beam of electromagnetic radiation such as X-rays and visible light. The invention substantially overcomes the expenses associated with locating analytical test equipment for testing semi-conductor wafers within clean room facilities.

Apparatus for use with analytical measuring instruments using

An edge-coupled optoelectronic device is mounted in a TO-style package which comprises a substrate assembly, a circular header and a cylindrical cap. A substrate and an insulating cover of the substrate assembly extend through an opening of the circular header and are secured in that opening. The optoelectronic device is secured to the substrate at a device support location. Electrical conductors are wire-bonded at contacts of the optoelectronic device and at corresponding device contacts of the substrate assembly to electrically connect the contacts of the optoelectronic device to respective conductors of the substrate assembly. The cylindrical cap is secured onto the header over the optoelectronic device.

Packaging method and package for edge-coupled optoelectronic device

A passive fiber optic device and optical fiber connected to it are packaged in a solid block of a bismuth containing fusible alloy. The alloy exhibits appreciable expansion on solidification, negligible dimensional change after solidification, and a low thermal expansion coefficient. Coupled with its low melting point and glass wetting ability, the alloy is uniquely adapted for forming a hermetic seal with glass. By molding as a solid block, the packaging operation is rendered simple and rapid.

Hermetic optical attenuator

A hermetic seal for an optical fiber is fabricated by casting or molding a mass of fusible alloy around the fiber so that the alloy solidifies within a confined space. The alloy used is characterized by low thermal coefficient of expansion, minimal relaxation after solidification, and appreciable expansion as it solidifies, thereby to create a stable pressure contact at its interface with the optical fiber. The solidified mass may be subsequently soldered into a passage through a wall of a fiber optic device package. Alternatively, the mold within which the mass of alloy is encased or molded may, itself, be soldered into the passage.

Optical fiber hermetic seal

A known electro-optic has a semiconductor laser, a temperature sensor for controlling an electrically operated cooler, and an optical fiber end portion anchored close to the laser to receive light from it. Usually the fiber is anchored by a mass of cured epoxy. This invention proposes anchoring the fiber in a mass of fusible alloy which is melted and solidified using a Peltier effect device which is driven with one polarity current to function as a heater and with a reverse polarity current to function as a cooler. Once the package is complete and the laser is operating, the temperature sensor together with the Peltier effect device functioning as a cooler are used to cool the laser.

Light emitting device package having combined heater/cooler

In a method and apparatus for bonding a semiconductor laser chip to a heatsink and testing the bond obtained, temperature in the bonding operation is regulated by passing a small fixed current through the forward biased laser and monitoring corresponding change in voltage caused by alteration of the laser pn junction temperature. Current is passed to the laser through a floating contact consisting of a conducting vacuum pick-up pressed against the laser top surface. Bond integrity is subsequently tested at low temperature by passing a dc current greater than a threshold current through the laser and measuring the resulting light output and then passing a pulsed current with identical peak current level and again measuring light output. The difference in light output is a function of the bond thermal resistance.

Semiconductor laser bonding technique

An electro-optic device for stabilizing the output level of a Burrus-type light emitting diode (LED) utilizes a photodiode to monitor side emission from an active region of the LED. Side emission closely tracks top emission, which is launched into an output fiber. An electrical analog is derived from the monitored side emission and is applied in a feedback loop to control modulation level or bias current to the LED. In this way, peak optical output (for digital systems) or r.m.s. output and linearity (for analog systems) is stabilized. The monitoring photodiode and the LED may be spatially separate or may form a unitary structure.

Growing community of inventors

Ottawa, Canada

Tibor F Kovats