Distributed interface for parallel testing of multiple devices using a single tester channel

• US 6,499,121 B1
• Filed: 03/01/1999
• Issued: 12/24/2002
• Est. Priority Date: 03/01/1999
• Status: Expired due to Fees

• Current Assignee: FormFactor Incorporated
• Original Assignee: FormFactor Incorporated
• Inventors: Miller, Charles A., Roy, Richard S.
• Primary Examiner(s): Decady, Albert
• Assistant Examiner(s): Torres, Joseph D.
• Application Number:
  US09/260,463
• Time in Patent Office: 1,394 Days
• Field of Search: 714/718, 714/719, 714/724, 714/736
• US Class Current: 714/724
• CPC Class Codes: G01R 31/31905 Interface with the device under test [DUT], e.g. arrangements between the test head and the DUT, mechanical aspects, fixture
• CPC Class Codes: G01R 31/31926 Routing signals to or from the device under test [DUT], e.g. switch matrix, pin multiplexing
• CPC Class Codes: G01R 31/3193 with comparison between actual response and known fault free response receiver details G01R31/31924
• CPC Class Codes: G11C 2029/2602 Concurrent test
• CPC Class Codes: G11C 2029/5606 Error catch memory
• CPC Class Codes: G11C 29/48 Arrangements in static stores specially adapted for testing by means external to the store, e.g. using direct memory access [DMA] or using auxiliary access paths
• CPC Class Codes: G11C 29/56 External testing equipment for static stores, e.g. automatic test equipment [ATE]; Interfaces therefor
• CPC Class Codes: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation

Abstract

A system for testing a number of integrated circuit (IC) devices under test (DUTs) having interface circuitry coupled to a single or multi-channel tester for receiving data values from the tester and providing error information concerning the DUTs. The interface circuitry forwards data values (received from the tester over a single channel) to a number of DUTs in parallel. The circuitry performs comparisons using data values read from the DUTs, and in response generates error values indicative of the comparison. The error values may then be returned to the tester over the same or a different channel.

Claims

1. A contact assembly comprising:

two or more sets of first elements, each set of elements is to contact a plurality of signal locations of a separate device under test (DUT); and

first circuitry having an input to be coupled to a set of I/O lines of a tester and an output coupled to the two or more sets of elements, to provide a write data value, received from the tester, on each set of said elements,

the circuitry being further configured to read from each DUT a read data value, in response to receiving a read command from the tester over the set of I/O lines, perform a comparison between said read data value and an expected data value received from the tester, to determine an error in each DUT, and send an error value, indicative of the error in each DUT, to the tester over the set of tester I/O lines, wherein the first circuitry is coupled to receive the write data value over one or more data lines of the set of I/O lines, and the error value is to be carried by said one or more data lines used to carry the write data value;

two or more sets of second elements, each set of second elements to contact a plurality of signal locations of a separate device under test (DUT); and

second circuitry having an input to be coupled to a further set of I/O lines of the tester and an output coupled to the two or more sets of second elements, to provide a write data value, received from the tester and carried by one or more data lines of the further set of I/O lines, on each set of said second elements,

the second circuitry being further configured to read from each DUT that is contacted by the second elements a read data value, in response to receiving a read from the tester over the further set of I/O lines, perform a comparison using said read data value to determine an error in each DUT, and send a second error value, indicative of the error in each DUT that is contacted by the second elements, to the tester over the further set of I/O lines, the second error value to be carried by said one or more data lines in the further set of I/O lines used to carry the write data value.

2. The contact assembly of claim 1 wherein the first and second circuitry are formed as separate application specific integrated circuits (ASICs).

3. The contact assembly of claim 1 in combination with said tester having a set of I/O lines coupled to the input of the first circuitry in said contact assembly.

4. The contact assembly of claim 1 in combination with said tester, wherein the tester is configured to test a DUT as being a memory device.

5. The contact assembly and tester combination of claim 4 wherein each bit of the error value is to be carried on a separate one of said one or more data lines of the set of I/O lines, an error status of each DUT being represented by a separate bit of the error value.

6. The contact assembly of claim 1 wherein the sets of first and second elements are configured to contact each DUT as part of a packaged semiconductor integrated circuit device.

7. The contact assembly of claim 1 wherein the read data value and the error value are each no more than M bits long, the data lines of each set of I/O lines are M bits wide, and the error value contains information regarding errors in corresponding locations of two or more DUTs each of which can store data values up to M bits long.

8. The contact assembly of claim 1 wherein the error value does not indicate an exact bit location of an error in the DUTs.

9. The contact assembly of claim 1 wherein the first and second circuitry is to communicate with each DUT as being a memory device, and wherein the error value represents a difference between a data value read from a memory device and an expected data value received by the first and second circuitry for a predefined memory address.