Abstract: A test fixture with a single vacuum well and two vacuum chambers for use in the automatic testing of printed circuit boards is connected to an electronic circuit tester for performing high speed testing of circuits on the board. The fixture includes a vacuum well, two vacuum chambers formed by gaskets, a movable top plate for moving the circuit board and a stripper plate between two positions, and ar array of test probes disposed in the vacuum well for access to the circuit board. The board under test is placed on the test fixture and a first vacuum is drawn from the first vacuum chamber to move the plate, thereby engaging a first plurality of test probes with the board for performing functional tests. A second vacuum is drawn from the second vacuum chamber to move the printed circuit board to engage a second set of test probes. A second set of electrical test signals is communicated to both sets of test probes for a second in-circuit test.

Abstract: Integrated circuit (IC) packages mounted on a loaded printed circuit board (PCB) are tested by a translator module by first placing a corresponding module over each package. Each module has rows of spring contacts for releasably contacting corresponding electrical leads adjacent opposite sides of the IC package. An upper surface of the module has an array of electrically conductive test pads internally connected to corresponding contacts on the module. The test pads match an array of spring probes in the test unit. The module can be a molded plastic housing with metal leaf spring contacts, or it can comprise a composite flex-circuit material with individual contacts comprising flexible spring-like metalized plastic fingers. Contacts on the test module can releasably engage the leads on the IC package directly, or they can contact separate conductive leads on the PCB adjacent the leads on the IC package.

Abstract: Optical fiber test probes test the optical functions of light-emitting circuit elements or displays, or are used in optical test fixtures. In one embodiment, an optical fiber test probe comprises an optical fiber in two sections in which both are movable with a receptacle against the bias of a compression spring during testing. One fiber is contained within a removable barrel so it can be replaced by removing it from the receptacle independently of the compression spring. In their operative test position, the two optical fibers are mounted in the receptacle to maintain light-tight optical continuity during testing. In another embodiment, an optical fiber test probe comprises a barrel and an optical fiber contained within a plunger movable in the barrel, in which a free end portion of the optical fiber extends unsupported through a compression spring which applies a spring bias to an internal end of the plunger.

Abstract: Integrated circuit (IC) packages mounted on a loaded printed circuit board (PCB) are tested by a translator module by first placing a corresponding module over each package. Each module has rows of spring contacts for releasably contacting corresponding electrical leads adjacent opposite sides of the IC package. An upper surface of the module has an array of electrically conductive test pads internally connected to corresponding contacts on the module. The test pads match an array of spring probes in the test unit. The module can be a molded plastic housing with metal leaf spring contacts, or it can comprise a composite flex-circuit material with individual contacts comprising flexible spring-like metalized plastic fingers. Contacts on the test module can releasably engage the leads on the IC package directly, or they can contact separate conductive leads on the PCB adjacent the leads on the IC package.

Abstract: An electrical test probe comprises an outer barrel, and a plunger extending axially through the barrel and having an outer portion extending through an open end of the barrel and terminating in a contact tip outside the barrel for contact with a test point. The plunger is supported within the barrel by spring pressure for allowing spring biased relative axial motion between the plunger and the barrel. The plunger is rotatable about its axis during relative axial motion between the plunger and barrel against the bias of the spring so that rotation of the plunger causes enhanced contact between the probe and a test point on a circuit board under test.

Abstract: A test probe assembly includes a barrel having a hollow interior and a plunger which slides axially in the barrel. The plunger has an outer portion extending through an open end of the barrel, terminating in a contact tip outside the barrel for contact with a test point. In one embodiment, the plunger also has a hollow, elongated receptacle extending through the barrel. The receptacle has a geometric-shaped pilot hole, preferably square, spaced from the open end of the barrel. An elongated fixed guide member in the barrel extends through the pilot hole. The guide member extends through the interior of the barrel away from the pilot hole. The guide member has an outer surface of preferably square-shaped configuration engaging the pilot hole. A spring inside the barrel extends along the guide member and is biased against the internal end of the receptacle inside the barrel. Axial travel of the plunger into the barrel is against the bias of the spring.

Abstract: A breakaway switch probe comprises an outer barrel, a movable plunger in one end portion of the barrel, a terminal projecting from the other end of the barrel, and a breakaway clip mounted on the barrel and normally engaging a contact surface on the plunger for retaining the plunger in its at-rest position, substantially immovable in the barrel and out of contact with a switch point on the terminal. The plunger is normally retained in its at-rest position spaced from the switch point so that absence of contact between the plunger and the switch point produces an electrical open-circuit condition in electrical test circuitry connected to the probe. An external test force of less than the preset level applied to the plunger in opposition to the resistance force of the breakaway clip will not move the plunger from its at-rest position, thereby retaining the open-circuit test indication.

Abstract: A test fixture for use in computerized automatic test equipment for checking printed circuit boards. Substances are used to constitute some of the test fixture parts and to coat others which are effective in preventing damage from electrostatic charges. The substance must be permanent, substantially independent of humidity for its antistatic characteristics, and have a resistivity in the range of 10.sup.5 -10.sup.10 ohms/sq.

Abstract: A quick termination assembly for an electrical connector to a flexible wire. The connector comprises an electrical conductive tube. The tube has separate end opening and side opening to the passage and a ramp facing out of and extending towards the side opening from the passage. The end opening and passage are adapted to receive a bare end of the wire upon insertion therein, the ramp, during such insertion, forcing the bare wire to bend and move along the ramp out of the side opening to a position extended away from the tube. A non-conductive sleeve extends around the wire. The sleeve, as it is forced to slide along the wire and tube, engages the extended bare wire, causing the bare wire to bend against an exterior side of the tube and pass over and encircle the bare wire and tube, thereby gripping and retaining the bare wire and tube in electrical and mechanical contact with each other.