A wedge connector for integrated circuits comprises tapered fingers of conductive metal separated by an insulator. The tapered fingers are wedge-shaped, in that they are thinnest at their tips, so that they may more easily enter the space between adjacent legs of an integrated circuit (IC). A row of wedges is assembled, and spaced apart to interdigitate with the legs of the IC. The IC legs have sides that face each other along the direction of the row, and that are separated by the amount of the inter-leg spacing. The tapered fingers or wedges penetrate into the inter-leg space and contact the facing sides of the IC legs. Thus, the left-hand side of a wedge entering a particular inter-leg space will come into electrical contact with the right-hand side of the IC leg on the left of that inter-leg space, and the right-hand side of that wedge will come into electrical contact with left-hand side of the IC leg on the right of that inter-leg space. As the depth of penetration is increased the thicker parts of the wedge enter the inter-wedge space, filling it completely and causing good wiping action and firm contact pressure between the sides of the IC legs and the sides of the wedges. Within the row of wedges, the left-hand side of each wedge is electrically connected to the right-hand side of its neighboring wedge on the right, which, by implication means that the right-hand side of each wedge is also electrically connected to the left-hand side of its neighboring wedge to the right. To increase wedge compliance air gaps are provided between those portions of wedge internal layers of material that correspond to the tapered portions of the wedge. Correct initial interdigitation is improved by beveling the ends of the conductive surfaces at the tips of the wedges. Bridging of the conductive surfaces by solder debris accumulation at the tip of the wedge is eliminated by a center piece of insulating material at the central core of the wedge extending beyond the tapered end of the wedge by a small amount. The beveling also assists by reducing the amount of solder accumulated to begin with.
A portable wedge probe for perusing the signals of an IC is produced by mounting a short row of wedges in a housing that serves the dual purposes of: (1) Allowing the gripping and manipulation of the wedges for inspection, the connecting and unconnecting of interconnecting cables, deployment onto, and removal from, the IC; and (2) serving as the housing for and physical location of electrical interconnection(s) between the portable wedge probe and the cable(s) of the measurement (test) equipment. By the term "short row of wedges" we mean, say, two adjacent wedges for the signal on a single intervening interior pin of the IC, up to perhaps nine adjacent wedges for the eight signals on the eight intervening interior pins of the IC, as opposed to having the row of wedges being long enough to engage the entire side of the IC. The portable wedge probe is free standing once applied, and does not rely upon support from another row of wedges deployed on a different side of the IC.
An electrical test probe tip of the present invention has a longitudinal axis extending from a first end to a second end and an electrically conductive interior extending substantially therebetween. A conductive exterior-most surface at least partially surrounds the electrically conductive interior. The test probe tip has a maximum length measured from the first end to the second end and has a minimum length measured from the first end to the second end. An electrically insulated surface at the first end substantially descends from the maximum length to the minimum length. The electrical test probe tip may be inserted between a target IC pin and the electrically insulated surface faces the adjacent IC pin.
A probe system for electrical contact testing of a row of densely spaced wire bonding pads is provided comprising a plurality of probes, with each probe having a tip offset from the probe center axis. The probes may be mounted in a housing having an upper die and a lower die, and the lower die may be offset from the upper die. The probes are pivotally mounted in the holes of the upper die, and the probe bodies are convexly curved and extend down into the holes of the lower die. The bevel tipped probes may be arranged in two staggered and parallel rows of probes, with the tip of each probe oriented along the centerline formed between the two row of probes. The probes may be closely spaced in each row. The tips of the probes in one row are oriented 180 degrees with respect to the probes in the opposite row. The tips of each probe may also comprise a tip located along the center axis or a double bevel surface forming a tip at the apex of the two bevel surfaces.
A direct current and a modulation signal are simultaneously applied to contact pads on a device under test, such as a laser diode, with a probe that reduces signal distortion and power dissipation by transmitting a modulated signal through an impedance matching resistor and transmitting of a direct current over a second signal path that avoids the impedance matching resistor.
