Everett Charles Technologies, Inc.

Delaware Capital Formation, Inc.

Everett/charles Contact Products, Inc.

David R Van Loan

Mark A Swart

Charles J Johnston

Gary F St Onge

David J Wilkie

A test fixture for a printed circuit board having a pattern of test probes and a fixed probe plate and a top plate adapted for movement toward and away from the probe plate. The probe plate and the top plate have selected patterns of holes for passage of the test probes through the probe plate and the top plate for contacting test points on the printed circuit board which is supported at one end of the test fixture. A probe retention plate is positioned below the top plate in an area of the test probes to prevent the test probes from walking out of the probe plate. The fixture further includes a spacer plate including interface probes to convert the fixture between a wired and a wireless text fixture.

Floating spring probe wireless test fixture

A test fixture for a printed circuit board having a pattern of test probes and a fixed probe plate and a top plate adapted for movement toward and away from the probe plate. The probe plate and the top plate have selected patterns of holes for passage of the test probes through the probe plate and the top plate for contacting test points on the printed circuit board which is supported at one end of the test fixture. A probe retention sheet is positioned below the probe plate in an area of the test pins so that the test probes that extend through the probe plate also extends through the probe retention sheet, the probe retention sheet includes a preformed pattern of openings which are undersized with respect to an outside diameter of the test probes which extend through the pin retention sheet so that the retention sheet naturally applies a compression force around a circumference of the test probes extending through the sheet at a level sufficient to retain the test probes within the test fixture.

A translator fixture for a grid-type test fixture for testing circuit boards. In regions of the circuit board where test point density exceeds the grid spacing of probes in a grid base the test points are reached by a test module that plugs into the translator fixture and includes a grid pattern of feed-through probes for contacting special tilt pins connected to certain test points in the high density region of the board. Additional test probes, located between the rows and columns of feed-through probes, support special tilt pins for translating the remaining test points in the high density region of the board to contacts on flex circuit-type cables sandwiched on the module and extending to the periphery of the fixture for coupling to contacts on the grid base to communicate with test circuits in the test analyzer. A translator module providing an interface between the bottom of the translator fixture and the grid base includes a translator board overlying the grid base and translating test signals from a high density set of contacts on one side of the board to a standard pattern of contacts on the other side aligned with the test probes on the grid base. A receiver plate overlying the translator board receives tilt pins with a high density spacing and provides compliant connections to the high density pattern of contacts on the translator board.

Translator fixture with module for expanding test points

A translator fixture for a grid-type test fixture for testing circuit boards. In regions of the circuit board where test point density exceeds the grid spacing of probes in a grid base the test points are reached by a test module that plugs into the translator fixture and includes a grid pattern of feed-through probes for contacting special tilt pins connected to certain test points in the high density region of the board. Additional test probes, located between the rows and columns of feed-through probes, support special tilt pins for translating the remaining test points in the high density region of the board to contacts on flex circuit-type cables sandwiched on the module and extending to the periphery of the fixture for coupling to contacts on the grid base to communicate with test circuits in the test analyzer. In an alternate embodiment, a translator module providing an interface between the bottom of the translator fixture and the grid base includes a translator board overlying the grid base and translating test signals from a high density set of contacts on one side of the board to a standard pattern of contacts on the other side aligned with the test probes on the grid base. A receiver plate overlying the translator board receives tilt pins with a high density spacing and provides compliant connections to the high density pattern of contacts on the translator board.

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. During testing, the spring probes contact the test pads on the test modules and circuit continuity is established via the electrical connections from the spring probes through the modules to the leads adjacent the IC packages. The modules translate dense in-line spacing of leads adjacent the IC packages to the oversized in-line spacing of test pads on the module. In another embodiment, the translator module is attached to a flex-circuit cable coupled to the test system electronics. The translator module is manually placed over each IC package during testing. In a further embodiment, an integrated circuit package contains a built-in test verifier system so that standard test probes can be used to test the package without use of a separate translator module.

Test module hanger for test fixtures

A test fixture for testing circuit boards includes an array of test probes mounted to a probe plate and held in contact with test points in circuits printed on the board. The circuit array is indexed with respect to a fiducial mark on the board. The fiducial mark is sensed, and an optical reading shows the alignment or misalignment of the test points on the board relative to the probes. The top plate position is adjusted to move the board relative to the probes to correct misalignment. The optical reading indicates movement of the board to a corrected position necessary to align the test points to the probes. Board alignment can be optically sensed by a bore scope and an image enlarger and video probe that produce images of the fiducial mark and a known zero reference point on a video monitor. The zero reference is adjustable electronically during calibration. The top plate is movable by X- and Y-axis drive motors coupled to the fixture base and having separate output shafts for shifting the top plate in X, Y and Z-axis orientations. The drive motors are stopped when alignment is made and the top plate is retained in its fixed position during testing of the board.

Test fixture alignment system for printed circuit boards

A test fixture for testing printed circuit boards includes an array of test probes held in contact with a pattern of test points in a circuit array printed on the circuit board. The circuit array is positioned on the board with respect to a fiducial mark on the board, and a tooling pin hole on the board is aligned with the circuit array. The fixture includes a tooling pin inserted in the tooling pin hole to hold the circuit array in a fixed position relative to the test probes during testing. The fiducial mark is sensed, and an optical reading shows the alignment or misalignment of the test points on the board relative to the probes. The tooling pin is adjusted on the fixture to move the board relative to the probes to correct misalignment. The optical reading indicates movement of the tooling pin and board to a corrected position necessary to align the circuits on the board to the probe field. The alignment of the board on the fixture can be optically sensed by a lens system, fiber optic image conduit, light source, an image enlarger and video probe, removable from the fixture base, that produces images of the fiducial mark and a known zero reference point on a TV monitor. The zero reference is adjustable electronically during calibration. Alignment of the fiducial mark image to the reference point image produces precise alignment of the test probes and the circuit array.

Test fixture alignment system

Testing of integrated circuit devices on loaded printed circuit

A dual side access test fixture tests circuits on both sides of a printed circuit board. The fixture includes a housing, a lower probe plate in the housing, an array of lower test probes in the lower probe plate for contacting the bottom of the board, an upper probe plate on the housing for moving to a closed position above the board, and an array of upper test probes in the upper probe plate for contacting an upper surface of the board when the upper probe plate closed. A plurality of system interface pins in the housing are electrically connected to the lower test probes. An external upper interface connector mounted over the closed upper probe plate has a plurality of contacts for connection to corresponding upper test probes. Flex cables contained within the upper interface connector conduct test signals from the upper test probes directly to an external electronic circuit tester. A first set of test signals is communicated from the lower test probes through the interface pins to the circuit tester. Separately, a second set of test signals is communicated from the upper test probes through contacts in the upper interface connector to the flex cables and to the circuit tester, via direct electrical connections which circumvent electrical feed-through connections within the interior of the vacuum fixture housing.

Dual side access test fixture

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 includes a composite flex-circuit material with individual contacts including flexible spring-like metalized plastic fingers. Contacts on the test module can releasably engage the leads on the IC package directly, or they contact separate conductive leads on the PCB adjacent the leads on the IC package. During testing, the spring probes contact the test pads on the test modules and circuit continuity is established via the electrical connections from the spring probes through the modules to the leads adjacent the IC packages. The modules translate dense in-line spacing of leads adjacent the IC packages to the oversized in-line spacing of test pads on the module. The translator module is attached to a flex-circuit cable coupled to the test system electronics. The translator module is manually placed over each IC package during testing.

Growing community of inventors

Diamond Bar, CA, United States of America

David R Van Loan