Broad band contactor assembly for testing integrated circuit devices

• US 4,689,556 A
• Filed: 10/12/1984
• Issued: 08/25/1987
• Est. Priority Date: 10/12/1984
• Status: Expired due to Term

• Current Assignee: Daymarc Corp (COHU Incorporated)
• Original Assignee: Daymarc Corp (COHU Incorporated)
• Inventors: Cedrone, Nicholas J.
• Primary Examiner(s): Eisenzopf, Reinhard J.
• Assistant Examiner(s): Baker, Stephen M.
• Application Number:
  US06/660,475
• Time in Patent Office: 1,047 Days
• Field of Search: 324/158 P, 324/158 F, 324/72.5, 339/108 TP, 339/17 C, 339/17 F, 339/75 R, 339/75 M, 307/89, 333/12
• US Class Current: 324/756.02
• CPC Class Codes: G01R 1/0433 Sockets for IC's or transistors
• CPC Class Codes: H05K 13/082 Integration of non-optical monitoring devices, i.e. using non-optical inspection means, e.g. electrical means, mechanical means or X-rays
• CPC Class Codes: Y10S 439/912 with testing means

Abstract

A contactor assembly for testing electronic devices that are packaged with a dual-in-line pin array has an insulating base that mounts two rows of contacts, each adapted to flex into electrical connection with a pin of the device, and a pair of flexible ground planes each spaced closely from an associated one row of said contacts. A flexible, insulating spacer maintains the ground planes and their associated row of contacts with a substantially fixed spacing there between during the flexural movement of said contacts. In the preferred form, the upper edge of the ground planes adjacent the pins includes an arrangement for securing a chip electornic device, a capacitor or a resistor. The other end of the chip mounts a contact tip that makes electrical connection with an associated pin when the associated contact also connects with the pin. The signal path provided by the holder, chip and tip is extremely short, preferably less than 0.150 inch. The contacts and ground planes electrically surface mount on a contactor board. Flexible lower end portions of the contacts and ground planes make direct electrical connection with signal pads and ground planes on the board without the use of connectors. A flexible mount formed by strips of a conductive material having arms soldered to two or more contacts hold a surge capacitor that decouples the device from ground noise during large current surges.

Claims

1. A contactor assembly for testing electronic devices that are packaged with line of pins arrayed along at least one side of each of the electronic devices, comprising

a base formed from an insulating material;

a plurality of contacts arrayed in at least one row each of said contacts mounted on said base and having a first end which extends below said base and a second end which extends above the base and is adapted to make electrical connection with an associated pin of the device, each of said contacts being flexible to move between a first position where said second ends are spaced from said pins and a second position where said second ends are in electrical connection with said pins, each of said contacts being adapted to conduct an electrical signal along its length to or from an associated pin of the device;

at least one flexible ground plane also mounted on said base and each spaced closely from an associated row of said contacts and having a first end extending through said base and a second end spaced closely from said second contacts ends in said row, said ground plane providing a distributed capacitance with respect to said associated row of contacts such that the signal transmitted along said contacts encounters a substantially characteristic impedance;

means for maintaining said ground plates and their associated row of contacts with a substantially fixed spacing therebetween during the movement of said contacts between said first and second positions; and

means for providing a signal path to said ground plane from at least one of said pins that is extremely short and for at least high frequency components of said signal presents a virtually zero impedance, said signal path comprising a chip electronic device, chip holder means for connecting one of said chip devices to said ground plane at said second end, and means for placing the other end of said chip in electrical connection with said pin when said second contact end is in said second position.

2. The contactor assembly of claim 1 wherein said chip electronic device is a capacitor and said extremely short, virtual zero impedance path electrically decouples said device under test at said pin from other regions of the contactor assembly.

3. The contactor assembly according to claim 1 wherein said chip electronic device is a resistor.

4. The contactor assembly according to claim 3 wherein said resistor has a value that is substantially the same as the characteristic impedence of said contacts and their associated ground planes so that the signal lines of said contactor assembly are terminated in a characteristic impedance to substantially eliminate reflections at said pin.

5. The contactor assembly according to claim 1 wherein said placing means comprises a contact tip that extends from said chip electronic means generally toward said pin.

6. The contactor assembly according to claim 1 further comprising a contactor board having a plurality of signal pads arrayed on one surface in alignment with said contacts and wherein said first ends of said contacts terminate in flexible feet portions each adapted to make an electrical connection with one of said signal pads when said contactor assembly is surface mounted on said one surface.

7. The contactor assembly according to claim 6 wherein said one surface includes a ground plane and wherein said first ends of said outer flexible plates terminate in flexible feet portions adapted to make electrical connection with said ground plane.

8. The contactor assembly according to claims 6 or 7 wherein said base includes cavity means formed in a face of said contactor assembly that surface mounts on said contactor board for receiving said feet portions, said cavity means and said feet portions having dimensions that cause said feet to flex into a reliable electrical connection with said signal pads and said ground plane when said contactor assembly is assembled onto said board.

9. The contactor assembly according to claim 1 further comprising an electronic circuit element and means for mounting said electronic circuit element adjacent to said device under test, in electrical connection with at least two pins of said device, and accommodating the flexing movement of said contacts, ground planes, and spacing means between said first and second positions.

10. The contactor assembly according to claim 9 wherein said strips and at least one arm associated with that strip are formed integrally of a resilient conductive material.

11. The contactor assembly according to claim 9 wherein said mounting means includes at least one additional resilient conductive arm that is electrically connected between one of said strips and one of said contacts other than said contacts associated with said power pins to provide a shorting bar between these pins having a short path length.