Abstract: A solder self-alignment process for aligning a semiconductor chip (13) with, and bonding the chip to, a substrate (12) is preformed in an atmosphere rich in gaseous formic acid, at least during the melting step. It is preferred that the formic acid atmosphere be maintained during the self-alignment step and the step of cooling and hardening the solder elements (23). With this feature, one can completely avoid the use of any solid or liquid fluxes and avoid the consequences of such use. Nonetheless, the molten solder elements (23) dependably bond to the bonding surfaces and vertically align themselves.

Abstract: Selective off-premises jamming for premium CATV service is provided by using continuously running fixed-frequency oscillators (19.1-19.n) for generating jamming signals at each of a plurality of distribution locations (13). The frequency of each oscillator corresponds to the frequency of one of the premium channels. A remotely controlled switched network is provided at each distribution location for applying jamming signals only to those TV channels of the subscriber lines (14) upon which the corresponding subscriber (15) is not entitled to receive premium signals. Since jamming signals are not applied to the TV channels upon which subscribers are entitled to receive premium TV programs, there is no need for de-scrambling apparatus at the various subscriber locations. In various embodiments, the switched network may be an array of switches (20.1-20.n), an array of filter traps (32.1-32.n) or an array of parallel connected band-pass filters (41.1-41.n).

Abstract: As an optical fiber (12) is being drawn, air (14) is directed at a portion of the fiber as a succession of air pulses, the pulses having a frequency near the natural frequency of the fiber portion. The frequency of the air pulses is then varied over a range of frequencies that includes the natural frequency of the fiber portion. When the air pulse frequency equals the natural frequency of the fiber portion, a resonance occurs which greatly amplifies the amplitude of the vibration of the fiber portion. The large deflection of the fiber that occurs at resonance is easy to detect, and the air pulse frequency which causes such maximum deflection is taken as being equal to the resonant frequency and therefore to the natural frequency of the fiber portion. Changes of the detected resonant frequency can be interpreted in a straightforward manner as changes in optical fiber tension which, in turn, are used to make compensatory changes of the temperature of the furnace (10).

Abstract: An electronic device (12) is encapsulated by a curable material (15) which, prior to cure, comprises sixteen to twenty-three weight percent of a silicone resin, forty-six to seventy-three weight percent of silicon dioxide, four to fifteen weight percent of silicon hydride, and six to twenty-five weight percent of xylene. The silicone resin is selected from the group consisting of polydimethylsiloxane, polymethylphenylsiloxane, and a mixture of polydimethylsiloxane and polymethylphenylsiloxane. The silicone resin contains a platinum catalyst and has vinyl and/or hydride functional components.

Abstract: An electronic device encapsulant comprises polydimethyldiphenylmethylphenylsiloxane in which the mole ratio of the sum of the methyl-phenyl and diphenyl groups to the dimethyl groups is in the range of ten to forty percent. The normal bi-functional hydride terminations are replaced with tri-functional or tetra-functional hydride terminations.

Abstract: The invention is an improvement of a harmonically mode-locked ring laser of the type comprising means (12) defining an optical path, an active laser medium (15) for emitting coherent light to be transmitted along the optical path, and means (18) included in the optical path for causing the light to propagate along the path as a train of pulses having a period which is substantially equal to the transit time of light pulses in the optical path divided by an integer. The improvement is characterized in that the optical path includes a Fabry-Perot optical resonator (24) having a free spectral range substantially equal to the pulse repetition rate of the optical pulses in the ring laser. Under this condition, the Fabry-Perot resonator tends to equalize the energy, shape and width of the individual pulses.

Abstract: An optical waveguide (11) is composed substantially entirely of triazine.

Abstract: A semiconductor wafer 11 is mounted on an elongated member 18, one end of which is rotatable about a transverse axis (14), thereby to distribute a liquid on the upper surface of the wafer more evenly. In order to stabilize the rotation of the elongated member, a second elongated member is preferably attached end-to-end to the elongated member (18) and rotates with it. A counterweight (26) in the second elongated member moves during the rotation such that the distance between the wafer and the central axis and the distance between the center of the counterweight and the axis are substantially equal. The weight distribution is approximately symmetrical about the axis and the structure is dynamically stabilized. The counterweight and the wafer assembly may be moved during rotation by applying air pressure from a source (23) to pistons (13,26) in the two elongated member.

Abstract: VOD services are provided by providing at each subscriber location a switching apparatus (e.g., 23 of FIG. 2) which is remotely controlled from the head end (12) of the system. A set top box of each subscriber is provided with a single channel designation (X) for VOD reception. In response to a request from a subscriber for a particular TV program at a specified time, the provider at the head end actuates the switching apparatus (23) to permit the set top box to be tuned to a specified channel that corresponds to a channel upon which the requested VOD program will be transmitted. Then, when the subscriber selects on his set top box the single VOD channel designation (X), the set top box is capable of receiving the requested TV program on the specific TV channel of the transmission line (11) that has been designated for it by the provider at the head end.

Abstract: A method for testing an integrated circuit (IC) chip (10) in accordance with the invention comprises the step of forming a solder bump (14) on each of an array of bonding pads (13) on a first surface of the chip, in accordance with the known flip-chip method of IC device packaging. Each of the solder bumps (14) is inserted through an aperture (25) in a spacer member (22), the spacer member having a smaller thickness than the length of each solder bump, whereby each solder bump protrudes through an aperture. The solder bumps are then placed on a layer of anisotropic conductive material (11) which is arranged over an array of test fixture conductive pads so that the anisotropic conductive layer is sandwiched between the IC chip and the test fixture. The integrated circuit chip is then compressed against the anisotropic conductor material to establish electrical contact between the solder bumps of the integrated circuit chip and the test fixture conductor pads (17).

Abstract: The accuracy of detection of the quantity of a rosin flux residue (18) left on an electronic assembly (11) after a cleaning operation is improved by using gel permeation chromatography for such detection.

Abstract: In an MOCVD reactor, gases are channeled around the periphery of a baffle plate (15) so as to flow radially inwardly along a slotted injection plate (16). The slots (22) in the injection plate extend radially and are of non-uniform width so as to compensate for a non-uniform rate of deposition. The resultant flow over a rotating heated substrate (17) gives a more uniform deposit of epitaxially grown material.

Abstract: A bundle (12) of optical fibers (13) is fixed in a matrix array by apertures in a guiding plate (14) and a securing plate (15). The apertures (18) in the guiding plate are larger than those in the securing plate and the securing plate apertures (17) are funnel-shaped to aid in insertion of the fibers. Each row of optical fibers may be inserted simultaneously by mounting the row on a uniquely designed vacuum holder (26).

Abstract: A turning mirror in an optical waveguide structure is made by etching in the upper surface of the structure a cavity (18) that intercepts the path of light propagated by the waveguide (15, 16, 13). Preferably, the cavity is made to be asymmetric with the side (25) of the cavity remote from the waveguide sloping at typically a forty-five degree angle. The asymmetry can be introduced by using mask and etch techniques and treating the surface of the structure such that the etchant undercuts the mask on the side of the cavity remote from the waveguide to a greater extent than it undercuts the mask on the side of the cavity adjacent the waveguide.

Abstract: A laser (15) is mounted on a planar surface of a monocrystalline silicon mounting member (12). A spherical lens (20) is mounted in a monocrystalline silicon cover member (13) which, when abutted and registered to the mounting member (12), aligns the spherical lens with the laser so that the output light can be projected along a precise predetermined path. The spherical lens (20) is mounted in a first V-shaped groove (31) which is made in the cover member by masking and etching. A second V-shaped groove intersects the first groove and defines a V-shaped edge in one side of the first groove. The spherical lens is then seated in the first V-shaped groove such that it bears against two points of the V-shaped edge and against one side wall (35) of the first V-shaped groove. A second lens (19) is mounted in the cover member in the same manner as the first lens and directs laser light from a rear facet of the laser to a mirror 30 and hence to a photodetector (21) mounted in the cover member.

Abstract: Elements such as glass spheres (11) and optical fibers (30') are permanently bonded to aluminum surfaces (13) of substrates (12) by applying pressure along with energy to the interface of the element and the aluminum. For example, a glass sphere is bonded by pressing it against aluminum while heating the aluminum. As an alternative to heating, acoustic energy can be applied to the sphere along with the pressure. Glass optical fibers can be bonded to aluminum surfaces in the same manner.

Abstract: A holder member (32) is made with a configuration of indentations (33) corresponding to the indentations (24, 25) on a substrate (23) within which optical elements (11-14, 16-19) are to be bonded. Vacuum channels (34) are made in the holder member, each communicating with one of the holder indentations (33), through which a vacuum is applied to temporarily hold the optical elements in place. The substrate containing the indentations or grooves within which optical elements are to be bonded is then positioned above the optical elements mounted in the holder member (FIG. 8). The optical elements are simultaneously bonded to the substrate by lowering the substrate to contact the elements to effect the bond. After bonding, the holder vacuum is released and the substrate (23) is withdrawn with all of the optical elements (11-14, 16-19) bonded to it.

Abstract: A first flat surface portion (17) of an upper mounting member (11) is made to be parallel with a second flat surface portion (18) of a lower mounting member (12) by, first, supporting the lower mounting member on a spherical cushion of air defined by a lower surface portion (20). The first surface portion (17) is next brought into contact with the second surface portion (18) which causes an adjustment in the position of lower mounting member (12) so as to make the surfaces (17) and (18) coplanar. The air supply to the lower mounting member is then reversed to apply a vacuum which draws the lower mounting member (12) into contact with the support member (22) so as to fix the second surface portion (18) in a parallel relationship to that of the first surface portion (17).

Abstract: An optical waveguide (11) is composed substantially entirely of triazine. Various methods for making desired triazine waveguide patterns are described.

Abstract: A silicone rubber potting compound contains an alkoxysilane (.gamma.-glycidoxypropyltrimethoxysilane) as an adhesion promoter. Harmful effects caused by the adhesion promoter are alleviated by using as an additive a titanate having the form Ti(OR).sub.4, where R is an isopropyl, butyl, octyl, or acetylacetonate.