Intel® Socket Test Technology for LGA771
Intel® Socket Test Technology Application Note for the LGA771 Product Code JM8FKZLVA
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.
An ICT uses digital test vectors which execute very quickly when power is applied to the board— typically less than a couple of milliseconds depending upon test head capability. An MDA doesn’t power the board, but uses its analog measurement capability. Test time using an MDA is typically longer.
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. To compensate there are four pairs of Hcontrol and Lcontrol signals that allow the multiplexing of signals between power and ground electrical socket connections. Signal multiplexing provides testing for as many power and grounds as possible. Testing of resistors that are also on the test chip help to provide some additional open coverage not provided by the switch pairs.
The control signals are pulled to ground with a resistor to keep the switches in an OFF state when a powered test method is being used on an ICT.
Read the full Intel® Socket Test Application Note.