Test station

• US 4,926,118 A
• Filed: 02/22/1988
• Issued: 05/15/1990
• Est. Priority Date: 02/22/1988
• Status: Expired due to Term

• Current Assignee: Sym-Tek Incorporated of Minnesota
• Original Assignee: Sym-Tek Systems, Inc.
• Inventors: O'Connor, R. Bruce, Toth, Thomas E., Ross, James A.
• Primary Examiner(s): Eisenzopf, Reinhard J.
• Assistant Examiner(s): Nguyen, Vinh P.
• Application Number:
  US07/158,941
• Time in Patent Office: 813 Days
• Field of Search: 324/158 F, 324/73 PC, 324/158 P, 324/73 AT, 324/73 R, 209/513, 209/552, 209/657, 73/865.6
• US Class Current: 324/750.28
• CPC Class Codes: G01R 31/2868 Complete testing stations; systems; procedures; software aspects
• CPC Class Codes: G06F 11/24 Marginal checking or other specified testing methods not covered by G06F11/26, e.g. race tests

Abstract

A station for testing electrical devices under elevated and depressed temperature conditions, said devices being transported through and tested in the station while held in coordinated planar sets. The planarly arranged sets of devices are sequentially placed upon a platen movable along three mutually orthogonal axes. A test head has a plurality of electrical device contactors in planar arrangement corresponding to the arrangement of the devices sets. At least one axis along which the platen moves is orthogonal to a general plane of the contactors for establishing parallel contact between the devices and the contactors. During testing each of the leads of the devices resting upon the platen are electrically contacted by a contactor. The leads of the full set of electrical devices can be contacted simultaneously, or the leads can be contacted in subsets depending upon the capacity of the test head. The test head energizes and stimulates the electrical devices, and the responses of the devices are communicated to a tester via the test head. Prior to being deposited upon the platen, the planarly arranged sets of electrical devices are conveyed through a chamber which elevates or depresses the temperature of the devices to a selected testing temperature. Following testing, the sets of electrical devices are conveyed through a chamber which brings the temperature of the devices back to or near equilibrium with the temperature ambient to the test center.

Claims

1. A test station for electrical devices being transported in sets, each set being in or on a transport medium which holds the devices in a planar array with the leads of the devices all accessible from at least one common face of the array, comprising:

(a) a platen means having an upward facing flat surface upon which a transport medium containing an array of electrical devices is placed for testing with the leads of the devices accessible from above,

(b) a test head means having an planar array of electrical device lead contactors registerable with the leads of subsets of the devices and spaced above and in parallel with the platen means,

(c) means for moving the platen means to bring the contactors in registration and contact with the leads of the devices comprising an extensible post atop of which the platen means is affixed, and a base upon which the post is affixed and supported, the base being movable along two mutually orthogonal axes which are both normal to an axis of the post,

(d) a thermally insulated chamber in which are disposed the platen means and the contactors of the test head means, the insulation being for the purpose of maintaining the temperature cf the devices during test,

(e) means defined by walls of the chamber for ingress from the soak means and egress to the unsoak means of the electrical device arrays,

(f) means for closure of the ingress and egress,

(g) a lower wall of the chamber comprising a thermally insulated diaphragm means defining a central opening through which the extensible post extends, the diaphragm means being contractible in any given direction normal to the axis of the extensible post and simultaneously expandable in the opposite direction to permit full movement the trolley means, and

(h) means for thermally sealing the interface between the post and the diaphragm means.

2. The test station of claim 1 wherein the diaphragm means comprises two spaced diaphragms each concentrically convoluted and both supported by a plurality of suspension cables, the ends of each such cable being spooled around a pair of pulleys disposed at opposite margins of the diaphragm means and biased to rotate in opposite directions to keep their respective cable taut at all times, the space between the diaphragms being hermetically sealed and filled with a gas.

3. A test station for electrical devices being transported in sets, each set being in or on a transport medium which holds the devices in a planar array with the leads of the devices all accessible from at least one common face of the array, comprising:

(a) a platen means having an upward facing flat surface upon which a transport medium containing an array of electrical devices is placed for testing with the leads of the devices accessible from above,

(b) a test head means having an planar array of electrical device lead contactors registerable with the leads of subsets of the devices and spaced above and in parallel with the platen means,

(c) means for moving the platen means to bring the contactors in registration and contact with the leads of the devices comprising an extensible post atop of which the platen means is affixed, and a base upon which the post is affixed and supported, the base being movable along two mutually orthogonal axes which are both normal to an axis of the post,

(d) means for thermally soaking each device array prior to its being placed upon the platen means for testing,

(e) means for thermally unsoaking each device array following testing,

(f) a thermally insulated chamber in which are disposed the platen means and the contactors of the test head means, the insulation being for the purpose of maintaining the temperature of the devices during test,

(g) means defined by walls of the chamber for ingress from the soak means and egress to the unsoak means of the electrical device arrays,

(h) means for closure of the means for egress,

(i) a lower wall of the chamber comprising a thermally insulated diaphragm means defining a central opening through which the extensible post extends, the diaphragm means being contractible in any given direction normal to the axis of the extensible post and simultaneously expandable in the opposite direction to permit full movement the trolley means, and

(j) means for thermally sealing the interface between the post and the diaphragm means.

4. The test station of claim 3 wherein the diaphragm means comprises two spaced diaphragms each concentrically convoluted and both supported by a plurality of suspension cables, the ends of each such cable being spooled around a pair of pulleys disposed at opposite margins of the diaphragm means and biased to rotate in opposite directions to keep their respective cable taut at all times, the space between the diaphragms being hermetically sealed and filled with a gas.

5. A test station for electrical devices being transported in sets, each set being in or on a transport medium which holds the devices in a planar array with the leads of the devices all accessible from at least one common face of the array, comprising:

(a) a platen means having an upward facing flat surface upon which a transport medium containing an array of electrical devices is placed for testing with the leads of the devices accessible from above,

(b) a test head means having an planar array of electrical device lead contactors corresponding to the leads of the devices and spaced above and in parallel with the platen means,

(c) means for moving the platen means to bring the contactors in contact with the leads of the devices comprising an extensible post atop of which the platen means is affixed,

(d) a thermally insulated chamber in which are disposed the platen means and the contactors of the test head means, the insulation being for the purpose of maintaining the temperature of the devices during test,

(e) means defined by walls of the chamber for ingress from the soak means and egress to the unsoak means of the electrical device arrays,

(f) means for closure of the means for egress,

(g) an opening defined by a lower wall of the chamber through which the extensible post extends, and

(e) means for thermally sealing the interface between the post and the lower chamber wall.

6. The test station according to claim 5 further comprising:

(a) means for thermally soaking each device array prior to its being placed upon the platen means for testing, and

(b) means for thermally unsoaking each device array following testing.