Abstract:
A system is disclosed for maintaining an electrical connector assembly mounted on a printed circuit board during soldering of the assembly to the board. A housing has a plurality of terminals mounted therein. The terminals include solder tails projecting from the housing for insertion into respective holes in the printed circuit board. Each terminal is stamped in planar form of sheet metal material. The solder tails are arranged in a row of pairs thereof, with the solder tails in each row being in a plane transverse to the row. All of the solder tails are of similar shape with each solder tail including a straight intermediate section projecting from the housing, a straight tip section for insertion into a respective hole in the printed circuit board, and an offset curved section between the intermediate and tip sections. The curved section of one solder tail extends in a direction transverse to the row opposite to the curved section of the other solder tail in each pair thereof. Each curved section is shaped such that each solder tail engages the circuit board within its respective hole only at a portion of the curved section. The straight intermediate section and the straight tip section of each solder tail are collinear.
Abstract:
An interface printed circuit board is configured to be placed between a leadless component such as a surface mount package used to house a SAW device and a standard printed circuit board configured for solder joints in a leadless contact with the printed circuit board. The interface device is made using materials having similar characteristic thermal expansion properties as that of the printed circuit to with it is affixed. Solder pads are placed in offset pairs and interface board material is removed such that the combination causes the interface board to flex from the forces caused by the differing expansion coefficients of the solder, the package and the printed circuit boards. The configuration causes the relative movement between the leadless carrier and the printed circuit board to occur along a length of epoxy and glass board material by bending the epoxy and glass as opposed to applying tensional or compressive forces to the solder joints. Such an approach relieves the stress and resulting creep seen at solder joints in the typical solder joint or column. In addition, by segregating the input and output pads and placing a metal shield between them, crosstalk rejection of the components is improved.
Abstract:
A flexible electrical connection, and method for making such a connection, for mounting an electronic device, such as a semiconductor chip made primarily of silicon, on an organic substrate, such as a printed circuit board made of a glass material impregnated with epoxy resin, are disclosed. The flexible electrical connection comprises a circuit line attached to the surface of the organic substrate and having a floating terminus in a relatively low adhesive area of the organic substrate where it is desired to mount the electronic device on the organic substrate. The floating terminus includes a stress relief bend, and the flexible electrical connection relieves stresses, such as thermal stresses, which may otherwise damage the physical and/or electrical connection between the electronic device and the floating terminus of the flexible electrical connection when the electronic device is mounted on the surface of the organic substrate.
Abstract:
A lead frame that is suited for use on array types of integrated circuit packages to provide a high degree of compliance for absorbing mechanical stress induced by thermal changes includes a series of individual terminal elements that are connected in a strip form by means of break tabs disposed between adjacent elements. Each terminal element provides two spaced, generally parallel mounting surfaces that are resiliently connected to one another by means of an integral intermediate section. While the terminal elements are interconnected in strip form, one of the mounting surfaces of each element can be bonded to an associated attachment region on the semiconductor substrate. After all of the terminals of the strip have been so bonded, the break tabs between adjacent terminals can be removed to thereby separate the terminals from one another. The package which then results contains discrete compliant terminals which are suitable for subsequent surface attachment to the printed circuit board.
Abstract:
A flexible electrical connection, and method for making such a connection, for mounting an electronic device, such as a semiconductor chip made primarily of silicon, on an organic substrate, such as a printed circuit board made of a glass material impregnated with epoxy resin, are disclosed. The flexible electrical connection comprises a circuit line attached to the surface of the organic substrate and having a floating terminus in a relatively low adhesive area of the organic substrate where it is desired to mount the electronic device on the organic substrate. The floating terminus includes a stress relief bend, and the flexible electrical connection relieves stresses, such as thermal stresses, which may otherwise damage the physical and/or electrical connection between the electronic device and the floating terminus of the flexible electrical connection when the electronic device is mounted on the surface of the organic substrate.
Abstract:
A mounting structure of a flat-lead package-type electronic component wherein ends of lead terminals drawn out from a surface of a package are bent to be horizontal with respect to the plane of the package and other portions of said lead terminal are tilted inward by a desired angle with respect to the normal of the plane.
Abstract:
A compliant lead clip comprises a single strip of metal bent to form a C-shaped member and an S-shaped member, the two members having a common portion. An integrated circuit chip is inserted into the C-shaped member and soldered thereto after which the lower part of the S-shaped member is soldered to the top surface of a printed circuit board whereby the chip is supported above the printed circuit board. The S-shaped member bends or twists to absorb forces which would otherwise be exerted on the solder joints as a result of warpage of the printed circuit board or temperature changes where the chip carrier and printed circuit board have different thermal coefficients of expansion.
Abstract:
An electrical resistor comprising an elongated resistor body having a resistance wire winding extending between its ends and terminals at each end contact the resistance winding and each comprise a strip of given width having a first end portion extending about and secured with an end of the body, and a second end portion which extends in a direction transverse to the axis of the body and has a tip for being received through an opening in a printed circuit board. Each strip has an intermediate neck portion of reduced width which is positioned proximate to the resistor body and is twisted so that the second portion extends in a plane which is perpendicular to the axis of the body and in the same direction with and spaced from that of the other terminal allowing adjustment of the distance between their tips. The second end portions each have a shoulder proximate to its tip which is seated on the surface of a circuit board, fixing the position of the resistor and stabilizing its mounting thereon.The method of making an electrical resistor comprises the steps of segmenting a continuous wire wound core to provide resistor bodies, and cutting out portions of a continuous substantially plane strip of metal material at spaced locations therealong to provide narrow neck regions, and first and second end portions above and below each neck region.