Abstract: A metal sheet is attached to a ceramic substrate utilizing a weld pad formed of tungsten layer that is preformed onto the substrate and features a faying surface coated with a gold film. The sheet is superposed onto the gold film and scanned with a laser beam to fuse the sheet and the gold, without fusing the tungsten, thereby avoiding spalling of the metal and microcracking of the ceramic.

Abstract: This disclosure discusses a programmable frequency synthesizer arrangement having programming feedback capability used to avoid undesirable operation due to random hard and soft faults. The arrangement operates by supplying appropriate programming information, receiving the same, subject to random hard or soft faults, and, in response, directing the operation of a frequency synthesizer (10). The feedback capability is accomplished by generating a feedback signal (35, 36) indicative of the programming information as applied to the frequency synthesizer, generating a reference signal representative of the appropriate programming information, comparing the two signals, and blocking undesirable operation of the frequency synthesizer if the comparison indicates the occurrence of a random hard or soft fault. Further disclosed is a wireless communications transceiver with the programmable frequency synthesizer arrangement.

Abstract: An improved electrical component package comprises a component attached to a substrate by a plurality of multisolder interconnections. Each interconnection comprises a preformed spacer bump composed of a first solder alloy, preferably a lead-base tin alloy containing greater than 90 weight percent lead. The spacer bump is directly metallurgically bonded to a metallic electrical contact of the component and rests against a corresponding metallic electrical contact of the substrate, but is not bonded thereto. Each interconnection further comprises a sheath portion formed of a second compositionally distinct solder alloy having a liquidus temperature less than the first alloy solidus temperature. A preferred second solder is a tin-lead alloy comprising between about 30 and 50 weight percent lead and the balance tin or indium.

Abstract: An automated voice operated transmitter control (VOX) arrangement devoid of any separate manual actuation requirement and adaptable to a dynamic acoustic environment is described. The VOX decides whether it should be operating, automatically selects a threshold condition (70) from a predetermined list according to a average acoustic signal level over a first time period, and provides a VOX PTT signal to activate a radio frequency transmitter (24) when the acoustic signal level, over a second time period that is less than the first time period and exceeds a debounce time (78), exceeds the threshold condition.

Abstract: A low temperature-wetting solder paste for forming a tin-base solder connection comprises a mixture of compositionally distinct first and second solder powders. The first solder is formed predominantly of tin, preferably at least 90 weight percent. The second powder is formed of a tin alloy containing indium or bismuth and having a melting temperature less than the first powder. During soldering, the second powder melts during the early stages of the heating cycle to initiate wetting of the faying surfaces and promote dissolution of the first powder, thereby reducing the time and temperature required to form the solder connection.

Abstract: A method and means for controlling transmissions among a plurality of communication units is described that determines an inhibit state based upon an inhibit signal and information in a header preceding a coded message before allowing transmission. This inhibit state prevents all of the other remote units from transmitting while a prescribed remote unit transmits a coded message or an acknowledgment (ACK) so that collisions between messages and ACKs, or between one ACK and another, are avoided. Message-message collisions are substantially reduced since the method causes a remote unit to utilize a random delay before attempting a retry to send the message a second time. Hence, the method and arrangement better coordinates inbound transmissions to the base station so that collisions on the inbound channel to the base station are minimized.

Abstract: A solder connection (30) is formed based upon a tinindium or tin-bismuth alloy, but having a melting temperature greater than the melting temperature of the initial solder alloy. A deposit (26) of solder alloy is placed against a tin plate (24) applied, preferably by electrodeposition, to a first faying surface (18). Following assembling with a second faying surface (22), the assembly is heated to melt the solder deposit, whereupon tin from the tin plate dissolves into the solder liquid to form a tin-enriched alloy having an increased melting temperature.

Abstract: A process for etching a silicon substrate to form a feature such as a V-groove, utilizes a coating formed of an alkaline resistance polymer. A preferred polymer is poly(benzocyclobutene) resin. The coating is applied to the substrate and removed form a selected region whereupon the underlying silicon is etched with an alkaline solution. In one aspect, an optical fiber is inserted in the etched groove and coupled to an optical waveguide embedded within the coating.