Intel BX80616I3540, Design Manual, Page: 14 / 72

LGA1366 Socket
14 Thermal/Mechanical Design Guide
2.2 Attachment to Motherboard
The socket is attached to the motherboard by 1366 solder balls. There are no additional
external methods (that is, screw, extra solder, adhesive, and so on) to attach the
socket.
As indicated in Figure 2-4 , the Independent Loading Mechanism (ILM) is not present
during the attach (reflow) process.
2.3 Socket Components
The socket has two main components, the socket body and Pick and Place (PnP) cover,
and is delivered as a single integral assembly. Refer to
Appendix C for detailed
drawings.
2.3.1 Socket Body Housing
The housing material is thermoplastic or equivalent with UL 94 V-0 flame rating capable
of withstanding 260 °C for 40 seconds (typical reflow/rework). The socket coefficient of
thermal expansion (in the XY plane), and creep properties, must be such that the
integrity of the socket is maintained for the conditions listed in
Chapter 7 .
The color of the housing will be dark as compared to the solder balls to provide the
contrast needed for pick and place vision systems.
2.3.2 Solder Balls
A total of 1366 solder balls corresponding to the contacts are on the bottom of the
socket for surface mounting with the motherboard.
The socket has the following solder ball material:
• Lead free SAC (SnAgCu) solder alloy with a silver (Ag) content between 3% and
4% and a melting temperature of approximately 217 °C. The alloy must be
compatible with immersion silver (ImAg) motherboard surface finish and a SAC
alloy solder paste.
The co-planarity (profile) and true position requirements are defined in Appendix C .
Figure 2-4. Attachment to Motherboard
LGA 1366 Socket
ILM