Intel® Socket Test Technology Application Note for the LGA771 Product Code JM8FKZLVA February 2006 Document Number: 311708-001
Notice: This document contains information on products in the design phase of development. The information here is subject to change without notice. Do not finalize a design with this information. INFORMATION IN THIS DOCUMENT IS PROVIDED IN CONNECTION WITH INTEL® PRODUCTS. NO LICENSE, EXPRESS OR IMPLIED, BY ESTOPPEL OR OTHERWISE, TO ANY INTELLECTUAL PROPERTY RIGHTS IS GRANTED BY THIS DOCUMENT.
Contents 1 Introduction.........................................................................................................................7 1.1 Terminology...........................................................................................................8 1.2 Reference Documents...........................................................................................8 2 Theory ..................................................................................................................
Figures 1-1 2-1 4-1 4-2 4-3 7-1 4 Intel® Socket Test Technology for the LGA771 Socket-Test Chip JM8FKZLVA .. 7 Intel® Socket Test Technology for the LGA771 Socket-Block Diagram ............. 10 Typical Switch Pair Configuration ....................................................................... 15 Instrument Setup For Low Side Switch ............................................................... 16 Instrument Setup For High Side Switch ..............................................................
Tables 1-1 1-2 3-1 3-2 3-3 4-1 6-1 6-2 6-3 6-4 7-1 7-2 7-3 7-4 7-5 7-6 Application Note Terms and Descriptions ........................................................................................ 8 Reference Documents...........................................................................................8 Voltage Identifier Signals.....................................................................................11 Control Signals ..................................................................
Revision History Reference Number Revision Number 311708 -001 Description • Initial release of the document.
1 Introduction The Intel® Socket Test Technology for the LGA771 socket is a test chip that enables testing for the mechanical integrity and electrical continuity of both socket-to-board solder ball connectivity and socket-to-CPU contact connectivity. Once inserted into the board’s LGA771 socket, the test chip works with either in-circuit testers (ICT) or manufacturing defect analyzers (MDA) that have access to all the socket nets through test fixture probes.
Introduction 1.1 Terminology Table 1-1. Terms and Descriptions Term 1.2 Description ICT In-circuit Test LGA771 socket Processor in the 771-land package mates with the system board through a surface mount, 771-pin, LGA (Land Grid Array) socket. MDA Manufacturing Defect Analyzer VCCP Processor core voltage VTT IO termination voltage for the front side bus Reference Documents Table 1-2. Reference Documents Documents Notes TBD 1 NOTE: This section will be updated in the next version.
2 Theory The Intel® Socket Test Technology LGA771 socket test chip consists of an array of switch pairs. Each switch pair, together with a control signal, can be used to test one signal, one power, and one ground. The control signal enables the ON/OFF condition of each switch. Testing is accomplished by checking the ON and OFF condition of each switch. There are fewer signals than power and ground electrical socket connections.
Theory Figure 2-1.
3 Powered Testing With Digital Vectors (ICT) 3.1 Using Voltage Identifier (VID) Signals VCCP and VTT are used to power the test chip. The test chip does not provide control on the VID signals to establish a VCCP voltage when plugged into a socket. A VID signal combination should be connected to ground and controlled by the test equipment in such a way that an onboard VCCP is generated that equals the on-board VTT voltage.
Powered Testing With Digital Vectors (ICT) board under test. To prevent damage, drive only one control signal high at any time during the test while all others are low. The High Side switch of each switch pair is used to test a VCCP solder ball and contact along with the shared signal solder ball and contact of the High and Low Side switch pair.
Powered Testing With Digital Vectors (ICT) Table 3-3.
Powered Testing With Digital Vectors (ICT) 14 Application Note
4 Un-Powered Testing (MDA) The following test method was developed using an Agilent* 3070 Series II In-circuit tester in an un-powered mode. The technique and results should be similar when using test equipment with similar capabilities as described below. (Please note that Agilent was formerly known as Hewlett Packard* or HP). Table 4-1. Test Equipment Technique Bus Description S Bus Primary Source. Provides -10.0V to +10.
Un-Powered Testing (MDA) The resistance of the switch is equal to approximately 40 in the ON state and is infinite in the OFF state. In an isolated environment, the ON state voltage measured at the signal would be approximately 44mV as a voltage divider exists between the 40 switch resistance and the 500 resistance of the source termination. It has been observed that the OFF state voltage doesn’t reach the 600mV level that circuit theory would lead one to expect.
5 Board Design Impact on Test Results After the production of Intel® Socket Test Technology for LGA771 had begun, changes were made to board design around the processor socket that will impact test results. These changes affect four pins—A24, E29, G1, and U1—that were connected to the VSS (Ground) plane in the original board design. The pins are still in the GND column of the Ball Usage tables in Section 7, but they have been high-lighted in grey to call attention to the change.
Board Design Impact on Test Results 18 Application Note
6 Related Specifications Operating temperature: Between 10° C and 50° C Electrostatic Discharge (ESD) Environment: Controlled to less than 300 volts Table 6-1. Electrical Operating Parameters Symbol Vccp Parameter Applied Voltage (Powered) Value Units 0.8 to 1.2 max V CtrlOnThres Switch On Threshold 300 mV HctrlEnVih High Switch Enable VIH (Powered) Vccp + 0.6 max V LctrlEnVih Low Switch Enable VIH (Powered) Vccp + 0.6 max V CtrlDisVil Switch Disable VIL 0.
Related Specifications Table 6-3. Test Condition for Low Side Switch (Powered Digital) Symbol Vccp Parameter Applied Voltage Value Units 1.2 max V Hcontrol Disable High Side Switch 0.0 V Lcontrol Enable Low Side Switch 1.8 max V Signal Maximum VOL 200 mV Signal Load Current Source from Signal to Vccp (Pull Up) 2 mA Signal VohTh Test VOH Threshold Setting 400 mV Signal VolTh Test VOL Threshold Setting 400 mV Value Units Table 6-4.
7 Ball Usage Table 7-1 identifies the balls used for the 4 control lines, also referred to as Lcontrol_0 – Lcontrol_1 and Hcontrol_0 – Hcontrol_1. Table 7-1. Balls Used as Control Signals Low Side Control (Lcontrol) High Side Control (Hcontrol) E6 E5 D14 D1 Table 7-2 maps the ball of the High and Low Side controls with the signal ball, ground ball and power ball for each switch pair. The table can be used to generate tests and diagnose test failures. Table 7-2.
Ball Usage Table 7-2.
Ball Usage Table 7-2.
Ball Usage Table 7-2.
Ball Usage Table 7-2.
Ball Usage Table 7-2.
Ball Usage Table 7-2.
Ball Usage The test chip’s 0Ω measurements, listed in Table 7-3, can be used to generate tests that can detect 0 resistance between the two points, thus adding more open test coverage. Table 7-3. 0Ω Measurements Shorted Ball Shorted Ball J1 D25 AA1 D26 AN4 AM4 AN3 AN8 F29 D28 The test chip has VID_0-VID_5 signals pulled to VCCP with 1k resistors. Socket electrical connections can be tested by measuring resistors between the respective electrical connections.
Ball Usage Table 7-6.
Ball Usage Figure 7-1.
