Abstract: A method of forming a high resolution metal pattern on a substrate. A temporary polyvinyl alcohol (10) layer underneath the photoresist layer (20) aids in removing the photoresist layer after plating. The photoresist is photodelineated in conventional manner to form a pattern (40). During photodelineation, the developing process for the resist does not completely remove the PVA (45) that lies directly under the removed resist, but instead reveals those portions of the polyvinyl alcohol layer. The substrate is then rinsed in a hot aqueous solution to effect removal of the revealed PVA portions, now exposing portions (40) of the substrate (15). Metal (50) is then electroplated to build up a metal circuitry pattern. The remaining portions of the photoresist and the PVA are then removed by a hot aqueous solution.

Abstract: A hazardous gas detection system is integrated into a wireless communication device such as a two-way radio. The radio has housing (102) with an opening (104) for receiving external air. A bellows-like device (114) has a first side (116) which is attached to an audio speaker diaphragm (112) by a rigid interconnect element (126). A fixed second side (118) of the bellows has first and second ports, 120 and 122. Vibrations from the speaker diaphragm are transferred to the bellows, causing the bellows to expand and contract. During bellows expansion, air is sucked into a first port (120) of the bellows. As the bellows contracts, the air is forced out through a second port (122) of the bellows and directed toward a gas sensor (132) mounted on an internal surface (106) of the radio housing. A warning mechanism in communication with the gas sensor provides forewarning of dangerously high gas concentration levels.

Abstract: An electrical circuit board (100) includes a substrate (101) on which a metallized bar code pattern (104) is disposed. The substrate (101) further includes an electrical circuit metallization pattern (103) which incorporates at least a portion of the metallized bar code pattern (104).

Abstract: An applicator (300) provides a tool for depositing processing media (510), such as a tacky flux agent, on predetermined surface areas (715) of a circuit substrate (705). The applicator (300) has a portion formed from a flexible compressible material with a surface (302, 325) patterned to have projections (325) that correspond in location to the predetermined surface areas (715) of the circuit substrate (705). The applicator (300) is preferably formed by polymerizing resin material using an image that corresponds to the circuit substrate (410, 420, 430).

Abstract: A multi-layer circuit substrate (500 ) includes at least two substrate layers (130, 150). The first substrate layer (130) has an insulating material (100) with two opposing surfaces (101, 102), and a hole (105) extending between the two surfaces (101, 102). A conductive pattern (110) is formed on a first surface (101) of the insulating material (100) and completely covers the hole (105). The second substrate layer (150) is attached along the second surface (102) of the insulating material (100), and also includes a conductive pattern (155) on insulating material. A conductive material (140) is disposed within the hole (105) that engages the first and second conductive patterns (110, 155).

Abstract: An assembly (5) has two or more plastic parts joined together. One of the plastic parts (20) has an electrical heating element (31) whose function is to soften a portion of the plastic when the heating element is electrically energized. Once the plastic is softened, the two parts can be separated and the assembly disassembled. When the two parts are joined together with snap-fit joints, the snap-fits have a heating element to soften a portion of the snap-fit (24) when the heating element is electrically energized, thereby allowing the housing to be opened and separated. If the two parts are ultrasonically welded together to form a housing, a heating element is located therein to soften the ultrasonically welded portion (44), thereby allowing the two halves of the housing to be separated. The heating element can be a nichrome or thin film resistor that is energized by a source (33) located within the housing, or by an power source external to the housing, or it may be inductively coupled to the power source.

Abstract: A soldering composition is self melting and is auto-regulating. The solder composition (100) has a central core (102) made from a non-magnetic metal. A coating (105) of a magnetic material surrounds most or all of the central core. A solder layer (108) overlies the coating of magnetic material, and the solder layer has a melting temperature that is lower than the Curie temperature of the magnetic material. The auto-regulating temperature substantially corresponds to the Curie temperature. When the solder composition is placed in a field of alternating current, the magnetic material heats up and melts the solder coating. When the Curie temperature is reached, the magnetic material stops heating, thus controlling the maximum temperature of the soldering composition. As the temperature of the composition drops below the Curie temperature, the magnetic material again heats up, thus keeping the temperature of the solder constant.

Abstract: A method of making a transfer molded chip carrier. A semiconductor device (10) is first electrically and mechanically attached to a substrate (12). The substrate (12) is then treated by sputter etching so that it will provide good adhesion between the substrate and a molding compound (18) that is subsequently molded to the substrate (25). Portions of the treated substrate are then selectively contaminated in order to reduce the adhesion between these selected portions of the substrate and the molding compound. The molding compound is then formed around the semiconductor device so as to encapsulate it and also part of the surface of the substrate. Portions (20) of the transfer molded material that were molded over the selectively contaminated portions of the substrate (12) are then removed by breaking away.

Abstract: An assembly (5) has two or more plastic parts joined together. One of the plastic parts (20) has an electrical heating element (31) whose function is to soften a portion of the plastic when the heating element is electrically energized. Once the plastic is softened, the two parts can be separated and the assembly disassembled. When the two parts are joined together with snap-fit joints, the snap-fits have a heating element to soften a portion of the snap-fit (24) when the heating element is electrically energized, thereby allowing the housing to be opened and separated. If the two parts are ultrasonically welded together to form a housing, a heating element is located therein to soften the ultrasonically welded portion (44), thereby allowing the two halves of the housing to be separated. The heating element can be a nichrome or thin film resistor that is energized by a source (33) located within the housing, or by an power source external to the housing, or it may be inductively coupled to the power source.

Abstract: A plastic leaded semiconductor package (20) has a semiconductor device (614) encapsulated in the package and mounted to a lead frame (612). The lead frame has a plurality of leads (622) that extend beyond the body (610) of the encapsulated package. Each of the plurality of leads is made from a metal having a predetermined coefficient of thermal expansion. A second metal (627) with a different coefficient of thermal expansion is disposed on at least one portion of each of the leads.

Abstract: A multichip circuit package is formed for use with an EPROM chip. The active circuitry on the EPROM die surface is revealed. An EPROM die (14) is mounted on an insulating substrate (10). The active circuitry (15) on the die is connected to a conductive circuit pattern (13) on the substrate by wire bonds (16) between the die and the conductive circuit pattern. A second integrated circuit die (20) is also mounted on the substrate and electrically connected to the conductive circuit pattern by wire bonds. A plastic material (50) is then molded to encapsulate the perimeter (18) of the EPROM and the associated thin wires, the entire second integrated circuit die and it's associated thin wires, at least a portion of the conductive circuit pattern, and portions of the insulating substrate. The plastic material is formed so as to expose the active circuitry on the face of the EPROM.

Abstract: A method of manufacturing a circuit carrying substrate having one or more coaxial via holes. The center core or inner layer (330) of the circuit carrying substrate is a dielectric material that has a plated (339) through hole or via (335) coupling the two surfaces of the inner layer together. One side of the inner layer has a first metallization pattern (336) and the other side has a second metallization pattern (338) on it. The through hole is electrically conductive (339) and connects portions of the first and second metallization patterns. The plated through hole is filled with a dielectric material (340). A first dielectric layer (342) is formed on one side of the inner layer, and a second dielectric layer (344) is formed on the other side of the inner layer, so that the dielectric layers cover the first and second metallization patterns and the filled via hole.

Abstract: An encapsulated electronic component having an integral heat diffuser. The heat producing electronic component (10) is mounted on a substrate carrier (12) and a layer of encapsulant material (16) covers the component. A layer of thermally conductive material (18) is applied over the encapsulant material, and then a second layer of encapsulant material (20) is applied over the thermally conductive material. The heat generated by the component is distributed throughout the thermally conductive material, thereby eliminating the hot spot over the component, resulting in a substantially lower surface temperature.

Abstract: A self centering coil (200) includes a coil section (202) and also having curved end section (206) and (204) at opposite sides of the coil section (202). The curved end sections are preferably substantially flat and in a plane which is parallel to the center axis (306) of the coiled section (202).

Abstract: A semiconductor device package comprises a substrate (10), a flip-chip (16), an underfill adhesive (25), and a thermally and electrically conductive plastic material (20). A leadless circuit carrying substrate has a metallization pattern (13) on a first side (15), one portion of the metallization pattern being a circuit ground (17). The second side has an array of surface mount solder pads (24) electrically connected to the metallization pattern by means of at least one conductive via (26) through the substrate. A semiconductor device (16) is flip-chip mounted to the metallization pattern by means of metal bumps (22). An underfill adhesive (25) fills the gap between the semiconductor device and the substrate. A thermally and electrically conductive plastic material (20) containing metal particles is transfer molded to encapsulate the semiconductor device, the underfill adhesive, and a portion of the first side of the leadless circuit carrying substrate, forming a cover.

Abstract: A selectively releasing runner and substrate assembly (10) comprises a plurality of conductive runners (16) adhered to a substrate (12). A portion (18) of at least some of the conductive runners have a lower adhesion to the substrate for selectively releasing the conductive runner from the substrate when subjected to thermal stress. The selectively releasing runner and substrate assembly is made by selectively depositing an adhesion layer (14) of a first metal to portions of the surface of the substrate where maximum adhesion is desired. The other portions of the substrate are not covered with the first metal. The first metal layer and the uncovered portions of the substrate surface are covered with a second metal layer (16). The adhesion of the second metal layer to the substrate is less than the adhesion of the second metal layer to the first metal layer, and less than the adhesion of the first metal layer tot he substrate. The second metal layer may be copper.

Abstract: An erasable programmable read only memory (EPROM) package whose storage information can be erased by irradiating with light of a certain wavelength. A semiconductor device (34) with an erasable programmable read only memory is mounted on a circuit carrying substrate (30). Synthetic resin (37) covers the semiconductor device and portions of the circuit carrying substrate to provide a package. A window (39) is formed in the resin to expose the erasable-programmable-read-only-memory circuit to light. The window is cross-polarized and normally opaque to the light and transmits the light when appropriately energized to remove the cross polarization. The light is typically in the ultraviolet frequency, and the window may be made from a liquid crystal material or a solid crystal material such as PLZT. Applying a voltage to the window causes the liquid crystal material in the window to become transparent and allow the EPROM to be erased.

Abstract: A selectively releasing runner and substrate assembly 10 comprises a plurality of conductive runners 16 adhered to a substrate 12, a portion 18 of at least some of the conductive runners 16 have a lower adhesion to the substrate for selectively releasing the conductive runner from the substrate when subjected to a predetermined stress.

Abstract: A three-dimensional printed circuit assembly is formed by first making a substrate (20). A substrate (20) is first formed from a photoactive polymer (14) that is capable of altering its physical state when exposed to a radiant beam (30). At this point, the substrate is only partially cured. A conductive circuit pattern (50) is then formed on the partially cured substrate. The substrate is then molded to create a three-dimensional structure, and then further cured to cause the photoactive polymer to harden.

Abstract: A method for applying solder on a substrate (12) comprises the steps of providing a substrate (12) having predefined solder pads (15) and then providing solder spheres (16) for suitable placement on the solder pads. Then applying flux (14) and tacking media (18) between the solder pads (15) and the solder spheres (16) and then placing the solder spheres on the solder pads. Subsequently the solder spheres are heated onto the solder pads of the substrate providing reflowed solder (26) on the solder pads. Then a layer of flux tacking media (28) is applied on the reflowed solder. Next, a component (30 or 40) is placed on the reflowed solder and flux tacking media providing a substrate assembly (10). Finally, the circuit assembly is heated allowing the component to be soldered to the solder pad.