Lenovo Intel Xeon E5520 67Y0011 Manuale Utente

Thermal/Mechanical Design Guide

21

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 to the board is expected to occur after wave 
solder. The exact assembly location is dependent on manufacturing preference and test 
flow.   

The ILM has two critical functions: deliver the force to seat the processor onto the 

socket contacts and distribute the resulting compressive 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.

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.

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 

. 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.