Abstract:
Calibration standards for accurate high frequency or wide bandwidth calibration measurements. A "short" or "reflect" standard is formed in a printed circuit board from a conductive coating on a generally planar surface. The conductive coating connects a signal trace to one or more ground planes. The generally planar surface is at least as wide as the signal trace and is preferably several times wider than the signal trace to provide a short standard with properties uniform over a wide frequency range. The short standard is incorporated into a printed circuit upon which a device under test is to be mounted. Connections to the short standard are made through components equivalent to components used to connect a device under test. When a through and line standard are added to the same board, the test board contains all the standards needed for a TRL calibration.
Abstract:
An electrical connector with electrically lossy materials bridging ground members. The lossy conductive members may be formed by filling a settable binder with conductive particles, allowing the partially conductive members to be formed through an insert molding process. Connectors assembled from wafers that contain signal conductors held within an insulative housing may incorporate lossy conductive members by having filled thermal plastic molded onto the insulatative housing. The lossy conductive members may be used in conjunction with magnetically lossy materials. The lossy conductive members reduce ground system do resonance within the connector, thereby increasing the high frequency performance of the connector.
Abstract:
A contact tail for an electronic component useful for attachment of components using conductive adhesive, which may be lead (Pb) - free. The contact tail is stamped, providing a relatively low manufacturing cost and high precision. The contact tail has a distal portion with a large surface area per unit length. The distal portion shapes conductive adhesive into a joint, holding the adhesive adjacent the lead for a more secure joint. Additionally, the distal portion holds adhesive to the contact tail before a joint is formed, facilitating the use of an adhesive transfer process to dispense adhesive. The further aid in the transfer of adhesive, the contact tail may be formed with concave portions, which increase the volume of adhesive adhering to the contact tail. By adhering an increased but controlled amount of adhesive to the contact tail, arrays of contact tails may be simply and reliably attached to printed circuit boards and other substrates.
Abstract:
A contact tail for an electronic component compatible with surface mount manufacturing techniques. The contact tail is stamped, providing a relatively low manufacturing cost and high precision. High precision in the contact tails in turn provides more reliable solder joints across an array of contact tails in an electronic component. Further, the contact tail may be shaped to reduce the propensity for solder to wick from the attachment area during a reflow operation. Reducing the propensity of solder to wick reduces the chance that solder will interfere with the operation of the electronic component. Additionally, reducing the propensity for solder to wick allows pads to which the contact tail is attached to be positioned over vias, thereby increasing the density with which contacts may be attached to a substrate. The reliability with which electronic assemblies incorporating components using the contact tail is also increased when the contact tail is used in self-centering arrays.
Abstract:
An improved open pin field connector is provided for enhanced performance when carrying high speed signals by selective application of one or more techniques for controlling electrical performance parameters. Lossy material may be positioned adjacent to conductive elements of the connector so as to reduce resonance in pairs of conductive elements and/or to provide a desired characteristic impedance for pairs of differential signal conductors. The lossy material may be shaped and positioned to avoid capacitive coupling that might otherwise increase cross talk. In a right angle connector, the lossy material may have a step-wise increase in thickness to provide comparable loss along longer and shorter conductive elements. Conductive elements may be shaped to balance performance characteristics of pairs selected to carry differential signals regardless of orientation along a row or column. Alternatively, conductive elements may have narrowed regions, covered with lossy portions, for reducing resonance while supporting DC signal propagation.
Abstract:
An improved power connector provides improved signal integrity in an interconnection system. The connector includes a filter element between a supply contact and a return contact. The filter element may be primarily capacitive, but may also include a resistance and a ferrite member. For connectors that include multiple sets of supply and return contacts, a single filter element may be included, or multiple filter elements may be included between multiple pairs of power and return contacts. The filter element may be formed within a connector housing or otherwise incorporated when the connector is manufactured. Alternatively, the filter element may be inserted into a receptacle such that filtering may be selectively incorporated as the connectors are used. When connected to a conducting loop for carrying power supply, the filter element provides substantially zero attenuation at frequencies below about 50 MHz and in excess of 10 dB of attenuation over a range that extends above 500 MHz.
Abstract:
A network interface adapted for high speed networks. The interface includes isolation circuits with a transformer containing two primary coils and two secondary coils. A wire making up each primary coil may be twisted with a wire making up a secondary. These two coils may then be co-wound on a common core. The transformer may be connected to a common mode choke. The isolation circuit may be packaged such that the transformer and coil are in a line, with isolation circuits for a plurality of pairs arranged in parallel. The interface circuit may be packaged in a connector housing, which also may be adapted for high speed performance. The housing may receive multiple isolation circuits in parallel. The housing may also include a mating contact portion in which mating contacts for signal conductors of each pair are positioned along the same side of a cavity.
Abstract:
An interconnection system with capacitors integrated into a printed circuit board footprint of an electrical connector. One end of each capacitor shares a pad on the printed circuit board with a contact tail of a conductive element in a connector. The shared pads are not connected through vias to internal circuit structures. Rather, a via, such as which would conventionally be formed as part of the connector mounting pad, is formed as part of a separate, adjacent pad. A second end of the capacitor is attached to the adjacent pad, forming an electrical connection between the conductive element and the via through the capacitor. Incorporating capacitors into the footprint reduces the number of vias required, which improves signal integrity. The capacitors may be placed on the printed circuit board separately from the connector or may be incorporated into the connector, allowing the connector and capacitors to be placed in one operation.
Abstract:
A high speed, high density surface mount connector which may be easily manufactured. The connector is formed by injection molding a ground plate into a portion of an insulative housing, leaving conducting beam portions and tail portions extending from opposite ends of the housing. A mating section of the housing is separately made. Signal contacts are sandwiched between the two pieces of the housing, which are then mated. The signal contacts are parallel to the ground plate but spaced apart from it, forming individual transmission lines. In use, the tail portions are soldered to a printed circuit board. The beam portions are bent to form contact springs. They make contact to a back plane when the connector is pressed against the back plane.
Abstract:
A multi-layer printed circuit board (30) includes a non-conductive via (54) which intersects a conductive trace (44) on an inner layer (38) of the board and is adapted to receive a conductive element (60) configured to make direct contact with the conductive trace (44). The non-conductive via (54) may extend through all or only a portion of the multi-layer board (30). Illustrative conductive elements (60) include a press fit contact, such as an eye-of-the-needle contact of an electrical component, a wedge-shaped contact, and a conductive polymer stripe. Also described is a stepped non-conductive via (160) having a reduced diameter portion (160a) intersecting an inner layer conductor (162) and a larger diameter portion (160b). The stepped via is adapted to receive a conductive element (166) having a reduced diameter portion (166a) in contact with the conductor and a larger diameter portion (166b) press-fit into the larger diameter (160b) portion to mechanically secure the conductive element (166) to the board.