Intel X3350 Design Guide - Page 26

Independent Loading Mechanism (ILM) 4 Independent Loading Mechanism (ILM) Note: Note: 4.1 4.1.1 The Independent Loading Mechanism (ILM) provides the force needed to seat the 1366-LGA land package onto the socket contacts. The ILM is physically separate from the socket body. The assembly of the ILM is expected to occur after wave solder. The exact assembly location is dependent on manufacturing preference and test flow. See the Manufacturing Advantage Service collateral for this platform for additional guidance. The ILM has two critical functions: deliver the force to seat the processor onto the socket contacts and distribute the resulting load evenly through the socket solder joints. The mechanical design of the ILM is integral to the overall functionality of the LGA1366 socket. Intel performs detailed studies on integration of processor package, socket and ILM as a system. These studies directly impact the design of the ILM. The Intel reference ILM will be "build to print" from Intel controlled drawings. Intel recommends using the Intel Reference ILM. Custom non-Intel ILM designs do not benefit from Intel's detailed studies and may not incorporate critical design parameters. Design Concept The ILM consists of two assemblies that will be procured as a set from the enabled vendors. These two components are ILM cover assembly and back plate. ILM Cover Assembly Design Overview The ILM cover assembly consists of four major pieces: load lever, load plate, frame and the captive fasteners. The load lever and load plate are stainless steel. The frame and fasteners are high carbon steel with appropriate plating. The fasteners are fabricated from a high carbon steel. The frame provides the hinge locations for the load lever and load plate. The cover assembly design ensures that once assembled to the back plate and the load lever is closed, the only features touching the board are the captive fasteners. The nominal gap of the frame to the board is ~1 mm when the load plate is closed on the empty socket or when closed on the processor package. When closed the load plate applies two point loads onto the IHS at the "dimpled" features shown in Figure 4-1. The reaction force from closing the load plate is transmitted to the frame and through the captive fasteners to the back plate. Some of the load is passed through the socket body to the board inducing a slight compression on the solder joints. August 2010 Order Number: 323107-002US Intel® Xeon® Processor C5500/C3500 Series and LGA1366 Socket Thermal/Mechanical Design Guide 26