38
Intel
®
Celeron
®
D Processor in the 775-Land LGA Package
Thermal Design Guide
Order #303730
LGA775 Socket Heatsink Loading
This board deflection metric provides guidance for mechanical designs that differ from the
reference design for ATX/µATX form factor.
A.2.2
Board Deflection Metric Definition
Board deflection is measured along either diagonal (refer to
):
d = dmax – (d1 + d2)/2
d’ = dmax – (d’1 + d’2)/2
Configurations in which the deflection is measured are defined in
.
To measure board deflection, follow industry-standard procedures such as IPC for board deflection
measurement. Height gauges and possibly dial gauges may also be used.
Table 6. Board Deflection Configuration Definitions
Configuration
Parameter
Pro Socket
load plate
Heatsink
Parameter Name
d_ref
Yes
No
Beginning of Life (BOL) deflection, no preload
d_BOL
Yes
Yes
BOL deflection with preload
d_EOL
Yes
Yes
End of Life (EOL) deflection
Figure 14. Board Deflection Definition
d1
d2
d’1
d’2