Abstract: An enhanced mechanism is disclosed for via stub elimination in printed wiring boards (PWBs) and other substrates. In one embodiment, the substrate includes a plurality of insulator layers and internal conductive traces. First and second through-holes extend completely through the substrate and respectively pass through first and second ones of the internal conductive traces, which are at different depths within the substrate. Photolithographic techniques are used to generate plated-through-hole (PTH) plugs of controlled, variable depth in the through-holes before first and second conductive vias are respectively plated onto the first and second through-holes. The depth of these PTH plugs is controlled (e.g., using a photomask and/or variable laser power) to prevent the first and second conductive vias from extending substantially beyond the first and second internal conductive traces, respectively, and thereby prevent via stubs from being formed in the first place.

Abstract: An enhanced mechanism is disclosed for via stub elimination in printed wiring boards (PWBs) and other substrates. In one embodiment, the substrate includes a plurality of insulator layers and internal conductive traces. First and second through-holes extend completely through the substrate and respectively pass through first and second ones of the internal conductive traces, which are at different depths within the substrate. Photolithographic techniques are used to generate plated-through-hole (PTH) plugs of controlled, variable depth in the through-holes before first and second conductive vias are respectively plated onto the first and second through-holes. The depth of these PTH plugs is controlled (e.g., using a photomask and/or variable laser power) to prevent the first and second conductive vias from extending substantially beyond the first and second internal conductive traces, respectively, and thereby prevent via stubs from being formed in the first place.

Abstract: A mechanism is disclosed for providing horizontally split vias in printed wiring boards (PWBs) and other substrates. In one embodiment, the substrate includes a plurality of insulator layers and internal conductive traces. First and second through-holes extend completely through the substrate and respectively pass through first/second ones and third/fourth ones of the internal conductive traces, which are at different depths within the substrate. Photolithographic techniques are used to generate plated-through-hole (PTH) plugs of controlled, variable depth in the through-holes before first/second conductive vias are plated onto the first through-hole and before third/fourth conductive vias are plated onto the second through-hole. The depth of these PTH plugs is controlled (e.g.

Abstract: An enhanced mechanism is disclosed for via stub elimination in printed wiring boards (PWBs) and other substrates. In one embodiment, the substrate includes a plurality of insulator layers and internal conductive traces. First and second through-holes extend completely through the substrate and respectively pass through first and second ones of the internal conductive traces, which are at different depths within the substrate. Photolithographic techniques are used to generate plated-through-hole (PTH) plugs of controlled, variable depth in the through-holes before first and second conductive vias are respectively plated onto the first and second through-holes. The depth of these PTH plugs is controlled (e.g., using a photomask and/or variable laser power) to prevent the first and second conductive vias from extending substantially beyond the first and second internal conductive traces, respectively, and thereby prevent via stubs from being formed in the first place.

Abstract: A mechanism is disclosed for providing horizontally split vias are provided in printed wiring boards (PWBs) and other substrates. In one embodiment, the substrate includes a plurality of insulator layers and internal conductive traces. First and second through-holes extend completely through the substrate and respectively pass through first/second ones and third/fourth ones of the internal conductive traces, which are at different depths within the substrate. Photolithographic techniques are used to generate plated-through-hole (PTH) plugs of controlled, variable depth in the through-holes before first/second conductive vias are plated onto the first through-hole and before third/fourth conductive vias are plated onto the second through-hole. The depth of these PTH plugs is controlled (e.g.

Abstract: A method and apparatus enables easy removal of a first substrate (e.g., a label, EMC gasket, etc.) from a second substrate (e.g., a cover of a computer enclosure) for enhanced reworkability or recyclability. An adhesive layer affixes the substrates to each other. A coating that includes a dewetting agent (DA) is interposed between the second substrate and the adhesive layer. Removal is facilitated by applying heat and/or pressure to activate the DA. Preferably, the DA thermally decomposes to form gaseous products at a predefined temperature. Heat may be applied through one or more of the substrates to drive the DA to decomposition, which forms bubbles that lift the first substrate relative to the second substrate. Optionally, the DA may be encapsulated in microspheres. For example, the DA may be silicone oil and/or an adhesive solvent encapsulated in microspheres and may be activated by applying pressure sufficient to crush the microspheres.

Abstract: Disclosed are heat management method, and system, and computer program product that include at least one optical strain gauge that is mounted on a printed board in proximity to an object being monitored for temperature changes. Power for controlling heat to the object is modified in response to changes in the optical reference signal of the gauge, whereby such changes are correlated to the rate of strain change in the object as measured relative to predefined temperature changes of the object being monitored.

Abstract: An electrical connector includes connector pads on a printed circuit board and contact members on an insulating substrate. The contact members are pressed against the contact pads by a compression mat having compressor fingers. A clamping arrangement forces the compressor fingers against the substrate and thereby presses the contact members against the contact pads. To counteract the inherent tendency of the compressor fingers to undergo stress relaxation after the compressor mat has been clamped, the connector also includes filler members disposed at least partially within the compressor fingers, essentially a “button-within-a-button” arrangement. Optionally, a filler deflection member may be interposed between the compression mat and a clamping plate of the clamping arrangement so that the filler deflection member abuts against the filler members. Alternatively, the filler members may be integral features of the deflection member.

Abstract: A novel Land Grid Array (LGA) interposer with adhesive-retained contacts and method of manufacture provide improved reliability in LGA mounting applications. A flexible adhesive is used to secure LGA interposer contacts to the walls of voids through an interposer frame. The contacts may be spring contacts or “fuzz button” type contacts. The use of a flexible adhesive provides for floating movement of the contacts within the voids so that thermal expansion stresses do not cause unbalanced compression of the contacts that could otherwise occur with a fixed attachment of the contacts to the frame. The resulting interposer can provide reliable electrical connection from LGA lands on an integrated circuit package to lands on an electronic assembly that is highly tolerant of thermal expansion differences, while eliminating migration of the contacts out of the voids that could otherwise cause shorting or disconnection.

Abstract: An electrical connector includes contact pads on a printed circuit board and contact members on a substrate. The contact members are pressed against the contact pads by a compression mat having compressor fingers. A clamping arrangement forces the compressor fingers against the substrate and thereby presses the contact members against the connector pads. The compression mat is made of elastomeric material, which has a tendency to relax and thus reduce the pressure after the clamping arrangement is tightened. A restrainer member is used to offset this tendency of the polymer to relax. The restrainer member has holes through which the compressor fingers of the compression mat extend.

Abstract: An electrical connector includes contact pads on a printed circuit board and contact members on a substrate. The contact members are pressed against the contact pads by a compression mat having compressor fingers. A clamping arrangement forces the compressor fingers against the substrate and thereby presses the contact members against the connector pads. The compression mat is made of elastomeric material, which has a tendency to relax and thus reduce the pressure after the clamping arrangement is tightened. A restrainer member is used to offset this tendency of the polymer to relax. The restrainer member has holes through which the compressor fingers of the compression mat extend.