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Method for time domain reflectometry base system for connector testing

IP.com Disclosure Number: IPCOM000007812D
Publication Date: 2002-Apr-24
Document File: 4 page(s) / 133K

Publishing Venue

The IP.com Prior Art Database

Abstract

Disclosed is a method for time domain reflectometry (TDR) base system for connector testing. Benefits include improved test environment, improved reliability, and decreased defects.

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Method for time domain reflectometry base system for connector testing

Disclosed is a method for time domain reflectometry (TDR) base system for connector testing. Benefits include improved test environment, improved reliability, and decreased defects.

Background

              The TDR principle is a proven technology in areas such as impedance measurement of high-speed digital circuits. TDR works on a principle much like radar. A pulse of energy is transmitted down a conductive material such as a cable. When that pulse reaches any edges or the end of the conductive material, pulses of energy are reflected back. This principle is applied to verify the successful mounting of a connector on a printed circuit board (PCB). Manufacturing defects such as missing connector pins, insufficient solder on joints, opens, and shorts can be detected.

              Conventionally, connectors (such as PCI, AGP, and DIMM type connectors) mounted on PCBs (such as motherboards or server boards) are tested in two processes, in-circuit automated test (ATE) and functional test (FT).

              In ATE, 100% pin coverage can be achieved for connectors, but because of the high cost, it is not feasible for low-cost board testing, such as for motherboards.

              In FT, 100% pin level coverage is practically impossible to achieve.

General description

              The disclosed method is connector testing using TDR. The test system configuration enables testing of PCB boards (such as motherboards and server boards), in an unpowered stage. An intermediate connector enables an additional (add-in) card to be plugged in that fits into the connector under test. After the connector is tested using the TDR with the PCB board unpowered, the system can be powered up for conventional powered testing.

      The key elements of the method include:

§         TDR principle applied to connector testing

§         Implementation of the system (see Figure 1)

§         Special intermediate connector used in this system (see Figure 2)

§         TDR profile learning (see Figure 3)

Advantages

              The di...