Intelligent Multi-Chip-Module (MCM) Package Enhancement
Original Publication Date: 2005-Jan-20
Included in the Prior Art Database: 2005-Jan-20
In recent years, the attachment of Multi-Chip Modules (MCM) to system boards using Land Grid Array (LGA) connectors has grown in popularity. To facilitate this attachment, high-force compression mounting systems have been designed which unfortunately have induced some substrate cracking failures. At present, the amount of force used to compress the MCM to the system board has been based on a series of calculations. This amount of force was then limited by either utilizing a preset torque (via a torque wrench) or a preset actuation distance (via a mechanical down-stop). In both cases, methods have proved acceptable, provided that nothing changed in the design of the board, MCM, LGA, or any other component used in the base calculation. However, if any one of the components have been changed by design, cost reduction reasons or product quality escapes, problems may occur. This article describes an approach that can be implemented that will provide "intelligence" to the assembly to prevent excessive mechanical loading from being imparted to the MCM.