Intel Xeon E5-2400 Guide

Reference Number: 327250-001
Intel® Xeon® Processor E5-2400
Product Family
Thermal/Mechanical Design Guide
May 2012

2Intel® Xeon® Processor E5-2400 Product Family
Thermal/Mechanical Design Guide
Legal Lines and Disclaimers
INFORMATION IN THIS DOCUMENT IS PROVIDED IN CONNECTION WITH INTEL® PRODUCTS. NO LICENSE, EXPRESS OR IMPLIED,
BY ESTOPPEL OR OTHERWISE, TO ANY INTELLECTUAL PROPERTY RIGHTS IS GRANTED BY THIS DOCUMENT. EXCEPT AS
PROVIDED IN INTEL'S TERMS AND CONDITIONS OF SALE FOR SUCH PRODUCTS, INTEL ASSUMES NO LIABILITY WHATSOEVER,
AND INTEL DISCLAIMS ANY EXPRESS OR IMPLIED WARRANTY, RELATING TO SALE AND/OR USE OF INTEL PRODUCTS INCLUDING
LIABILITY OR WARRANTIES RELATING TO FITNESS FOR A PARTICULAR PURPOSE, MERCHANTABILITY, OR INFRINGEMENT OF ANY
PATENT, COPYRIGHT OR OTHER INTELLECTUAL PROPERTY RIGHT. Intel products are not intended for use in medical, life saving,
life sustaining, critical control or safety systems, or in nuclear facility applications.
Intel may make changes to specifications and product descriptions at any time, without notice.
Designers must not rely on the absence or characteristics of any features or instructions marked “reserved” or “undefined.” Intel
reserves these for future definition and shall have no responsibility whatsoever for conflicts or incompatibilities arising from future
changes to them.
The Intel® Xeon® E5-2400 Product Family may contain design defects or errors known as errata which may cause the product to
deviate from published specifications. Current characterized errata are available on request.
Requires a system with Intel® Turbo Boost Technology. Intel Turbo Boost Technology and Intel Turbo Boost Technology 2.0 are only
available on select Intel® processors. Consult your PC manufacturer. Performance varies depending on hardware, software, and
system configuration. For more information, visit http://www.intel.com/go/turbo
Contact your local Intel sales office or your distributor to obtain the latest specifications and before placing your product order.
Copies of documents which have an order number and are referenced in this document, or other Intel literature may be obtained
by calling 1-800-548-4725 or by visiting Intel's website at http://www.intel.com.
Intel, Xeon, and the Intel logo are trademarks or registered trademarks of Intel Corporation or its subsidiaries in the United States
and other countries.
*Other names and brands may be claimed as the property of others.
Copyright © 2012, Intel Corporation. All Rights Reserved.

Intel® Xeon® Processor E5-2400 Product Family 3
Thermal/Mechanical Design Guide
Contents
1Introduction..............................................................................................................9
1.1 References ....................................................................................................... 10
1.2 Definition of Terms............................................................................................10
2 LGA1356 Socket ......................................................................................................13
2.1 Board Layout....................................................................................................15
2.2 Attachment to Motherboard ................................................................................16
2.3 Socket Components...........................................................................................16
2.3.1 Socket Body Housing..............................................................................16
2.3.2 Solder Balls...........................................................................................16
2.3.3 Contacts ...............................................................................................17
2.3.4 Pick and Place Cover...............................................................................17
2.4 Package Installation / Removal ...........................................................................18
2.4.1 Socket Standoffs and Package Seating Plane..............................................19
2.5 Durability.........................................................................................................19
2.6 Markings..........................................................................................................19
2.7 Component Insertion Forces ...............................................................................20
2.8 Socket Size ......................................................................................................20
2.9 LGA1356 Socket NCTF Solder Joints.....................................................................20
3 Independent Loading Mechanism (ILM) and Back Plate...........................................23
3.1 Design Concept.................................................................................................23
3.1.1 ILM Assembly Design Overview................................................................23
3.1.2 ILM Back Plate Design Overview...............................................................24
3.1.3 Durability..............................................................................................24
3.2 Assembly of ILM to a Motherboard.......................................................................25
3.3 ILM Cover ........................................................................................................27
4 LGA1356 Socket, ILM and Back Plate Electrical, Mechanical, and Environmental
Specifications29
4.1 Component Mass...............................................................................................29
4.2 Package/Socket Stackup Height ..........................................................................29
4.3 Socket Maximum Temperature............................................................................29
4.4 Loading Specifications........................................................................................30
4.5 Electrical Requirements......................................................................................30
4.6 Environmental Requirements ..............................................................................31
5ThermalSolutions...................................................................................................33
5.1 Boundary Conditions..........................................................................................33
5.2 Assembly .........................................................................................................35
5.2.1 Thermal Interface Material (TIM)..............................................................36
5.3 Structural Considerations ...................................................................................36
5.4 Thermal Design.................................................................................................36
5.4.1 Thermal Characterization Parameter .........................................................36
5.5 Fan Speed Control.............................................................................................37
5.5.1 Fundamentals........................................................................................37
5.6 Thermal Features .............................................................................................. 37
5.6.1 TCONTROL and DTS Relationship..............................................................38
5.6.2 Short Duration TCC Activation and Catastrophic Thermal
Management for Intel® Xeon® Processor E5-2400 Product Family................ 39
5.6.3 Intel® Turbo Boost Technology................................................................40
5.7 Thermal Guidance .............................................................................................40
5.7.1 Thermal Excursion..................................................................................40
5.7.2 Absolute Processor Temperature ..............................................................40

4Intel® Xeon® Processor E5-2400 Product Family
Thermal/Mechanical Design Guide
5.8 DTS Based Thermal Specification.........................................................................41
5.8.1 Compliance to Tcase Based Thermal Profile ................................................41
5.8.2 Considerations for Follow-on Processor ......................................................41
5.8.3 DTS Based Thermal Profile, Tcontrol and Margin
for the Intel® Xeon® Processor E5-2400 Product Family .............................41
5.8.4 Power Calculation for the Intel® Xeon® Processor E5-2400 Product Family....42
5.8.5 Averaging the DTS Based Thermal Specification for the
Intel® Xeon® Processor E5-2400 Product Family........................................42
5.8.6 Capabilities for the Follow-on Processor .....................................................43
6 Quality and Reliability Requirements .......................................................................45
6.1 Test Conditions .................................................................................................45
6.2 Intel Reference Component Validation ..................................................................45
6.2.1 Board Functional Test Sequence ...............................................................45
6.2.2 Post-Test Pass Criteria.............................................................................45
6.2.3 Recommended BIOS/Processor/Memory Test Procedures .............................46
6.3 Material and Recycling Requirements....................................................................46
A Component Suppliers...............................................................................................47
A.1 Intel Enabled Supplier Information.......................................................................47
A.1.1 Intel Reference Thermal Solution ..............................................................47
A.1.2 Intel Collaboration Thermal Solution..........................................................47
A.1.3 Alternative Thermal Solution ....................................................................48
A.1.4 Socket, ILM and Back Plate ......................................................................50
B Mechanical Drawings ...............................................................................................51
C Socket Mechanical Drawings....................................................................................85
D Processor Installation Tool ......................................................................................91
E Embedded Thermal Solutions...................................................................................93
E.1 Performance Targets..........................................................................................93
E.2 Thermal Design Guidelines..................................................................................94
E.2.1 High Case Temperature Thermal Profile .....................................................94
E.3 Mechanical Drawings and Supplier Information ......................................................95
Figures
1-1 Intel® Xeon® Processor E5-2400 Product Family Platform Socket Stack .................... 9
2-1 LGA1356 Socket with Pick and Place Cover Removed..............................................13
2-2 LGA1356 Socket Contact Numbering (Top View of Socket) ......................................14
2-3 LGA1356 Socket Land Pattern (Top View of Board).................................................15
2-4 Attachment to Motherboard.................................................................................16
2-5 Pick and Place Cover ..........................................................................................17
2-6 Package Installation / Removal Features...............................................................18
2-7 Package and Board Enabling Mark (-2) .................................................................19
2-8 LGA1356 NCTF Solder Joints ...............................................................................21
3-1 ILM Assembly....................................................................................................24
3-2 Back Plate ........................................................................................................25
3-3 ILM Assembly....................................................................................................26
3-4 Pin1 and ILM Lever ............................................................................................27
4-1 Flow Chart of Knowledge-Based Reliability Evaluation Methodology...........................32
5-1 Best-fit Equations ..............................................................................................34
5-2 1U Reference Heatsink Assembly .........................................................................35
5-3 Processor Thermal Characterization Parameter Relationships ...................................37
B-1 Board Keepin / Keepout Zones (Sheet 1 of 4)........................................................52

Intel® Xeon® Processor E5-2400 Product Family 5
Thermal/Mechanical Design Guide
B-2 Board Keepin / Keepout Zones (Sheet 2 of 4)........................................................53
B-3 Board Keepin / Keepout Zones (Sheet 3 of 4)........................................................54
B-4 Board Keepin / Keepout Zones (Sheet 4 of 4)........................................................55
B-5 1U Reference Heatsink Assembly (Sheet 1 of 2) ....................................................56
B-6 1U Reference Heatsink Assembly (Sheet 2 of 2) ....................................................57
B-7 1U Reference Heatsink Fin and Base (Sheet 1 of 2)................................................58
B-8 1U Reference Heatsink Fin and Base (Sheet 2 of 2)................................................59
B-9 Heatsink Shoulder Screw (1U, 2U and Tower) .......................................................60
B-10 Heatsink Compression Spring (1U, 2U and Tower) .................................................61
B-11 Heatsink Retaining Ring (1U, 2U and Tower).........................................................62
B-12 Heatsink Load Cup (1U, 2U and Tower)................................................................63
B-13 2U Collaborative Heatsink Assembly (Sheet 1 of 2)................................................64
B-14 2U Collaborative Heatsink Assembly (Sheet 2 of 2)................................................65
B-15 2U Collaborative Heatsink Volumetric (Sheet 1 of 2) ..............................................66
B-16 2U Collaborative Heatsink Volumetric (Sheet 2 of 2) ..............................................67
B-17 Tower Collaborative Heatsink Assembly (Sheet 1 of 2) ...........................................68
B-18 Tower Collaborative Heatsink Assembly (Sheet 2 of 2) ...........................................69
B-19 Tower Collaborative Heatsink Volumetric (Sheet 1 of 2)..........................................70
B-20 Tower Collaborative Heatsink Volumetric (Sheet 2 of 2)..........................................71
B-21 1U Reference Heatsink Assembly with TIM (Sheet 1 of 2) .......................................72
B-22 1U Reference Heatsink Assembly with TIM (Sheet 2 of 2) .......................................73
B-23 2U Reference Heatsink Assembly with TIM (Sheet 1 of 2) .......................................74
B-24 2U Reference Heatsink Assembly with TIM (Sheet 2 of 2) .......................................75
B-25 Tower Reference Heatsink Assembly with TIM (Sheet 1 of 2)...................................76
B-26 Tower Reference Heatsink Assembly with TIM (Sheet 2 of 2)...................................77
B-27 25.5 mm Reference Heatsink Assembly (Sheet 1 of 2) ...........................................78
B-28 25.5 mm Reference Heatsink Assembly (Sheet 2 of 2) ...........................................79
B-29 25.5 mm Reference Heatsink Fin and Base (Sheet 1 of 2).......................................80
B-30 25.5 mm Reference Heatsink Fin and Base (Sheet 2 of 2).......................................81
B-31 25.5 mm Reference Heatsink Assembly with TIM (Sheet 1 of 2)...............................82
B-32 25.5 mm Reference Heatsink Assembly with TIM (Sheet 2 of 2)...............................83
C-1 Socket Mechanical Drawing (Sheet 1 of 4) ............................................................86
C-2 Socket Mechanical Drawing (Sheet 2 of 4) ............................................................87
C-3 Socket Mechanical Drawing (Sheet 3 of 4) ............................................................88
C-4 Socket Mechanical Drawing (Sheet 4 of 4) ............................................................89
D-1 Processor Installation Tool..................................................................................92
E-1 ATCA Heatsink Performance Curves.....................................................................94
E-2 NEBS Thermal Profile.........................................................................................95
E-3 ATCA Reference Heat Sink Assembly (Sheet 1 of 2) ...............................................97
E-4 ATCA Reference Heat Sink Assembly (Sheet 2 of 2) ...............................................98
E-5 ATCA Reference Heatsink Fin and Base (Sheet 1 of 2)............................................99
E-6 ATCA Reference Heatsink Fin and Base (Sheet 2 of 2).......................................... 100
Tables
1-1 Reference Documents........................................................................................10
1-2 Terms and Descriptions......................................................................................10
4-1 Component Mass...............................................................................................29
4-2 1356-land Package and LGA1356 Socket Stackup Height........................................29
4-3 Socket and ILM Mechanical Specifications.............................................................30
4-4 Electrical Requirements for LGA1356 Socket ......................................................... 31
5-1 Values Used to Generate Processor Thermal Specifications......................................33
5-2 Performance Expectations in Compact Electronics Bay (CEB)................................... 34

6Intel® Xeon® Processor E5-2400 Product Family
Thermal/Mechanical Design Guide
5-3 TCONTROL and DTS Relationship .........................................................................38
5-4 Sign Convention ................................................................................................38
5-5 TCONTROL Relief for Intel® Xeon® Processor E5-2400 Product Family........................39
5-6 Averaging Coefficients........................................................................................43
A-1 Suppliers for the Intel Reference Thermal Solution .................................................47
A-2 Suppliers for the Intel Collaboration Thermal Solution.............................................48
A-3 Suppliers for the Alternative Thermal Solution .......................................................48
A-4 LGA1356 Socket, ILM and Back Plate....................................................................50
B-1 Mechanical Drawing List......................................................................................51
C-1 Mechanical Drawing List......................................................................................85
E-1 8-Core/6-Core Processor Reference Thermal Boundary Conditions............................93
E-2 4-Core Processor Reference Thermal Boundary Conditions.......................................93
E-3 Embedded Heatsink Component Suppliers.............................................................95
E-4 Mechanical Drawings List ....................................................................................96

Intel® Xeon® Processor E5-2400 Product Family 7
Thermal/Mechanical Design Guide
Revision History
§
Document
Number Revision Number Description Date
327250 -001 • Initial release of the document. May 2012

8Intel® Xeon® Processor E5-2400 Product Family
Thermal/Mechanical Design Guide

Intel® Xeon® Processor E5-2400 Product Family 9
Thermal/Mechanical Design Guide
Introduction
1Introduction
This document provides guidelines for the design of thermal and mechanical solutions
for server and workstation processors in the Intel® Xeon® Processor E5-2400 Product
Family platform. The processors covered include those listed in the Intel® Xeon®
Processor E5-2400 Product Family Datasheet - Volume One. The components described
in this document include:
• The processor thermal solution (heatsink) and associated retention hardware.
• The LGA1356 socket, the Independent Loading Mechanism (ILM) and back plate.
The goals of this document are:
• To assist board and system thermal mechanical designers.
• To assist designers and suppliers of processor heatsinks.
Thermal profiles and other processor specifications are provided in the appropriate
Datasheet.
Figure 1-1. Intel® Xeon® Processor E5-2400 Product Family Platform Socket Stack

Introduction
10 Intel® Xeon® Processor E5-2400 Product Family
Thermal/Mechanical Design Guide
1.1 References
Material and concepts available in the following documents may be beneficial when
reading this document.
Notes:
1. Available at http://www.intel.com. Document numbers are subject to change.
2. Available at http://www.blauer-engel.de/en/index.php
3. Available at https://learn.intel.com/portal/scripts/general/logon.aspx.
4. Contact your local Intel Field Sales Representative.
1.2 Definition of Terms
Table 1-1. Reference Documents
Document Number Notes
European Blue Angel Recycling Standards 2
Intel® Xeon® Processor E5-2400 Product Family Datasheet -
Volume One 327248 1
Platform Environment Control Interface (PECI) Specification 4
Intel® Xeon® Processor E5-2400 Processor Product Family
Mechanical Model 327322 1
Intel® Xeon® Processor E5-2400 Processor Product Family
Thermal Model 327321 1
Manufacturing With Intel Components Using Lead-Free
Technology 3
Platform Digital Thermal Sensor (DTS) Based Thermal
Specifications and Overview 4
Table 1-2. Terms and Descriptions (Sheet 1 of 2)
Term Description
Bypass Bypass is the area between a passive heatsink and any object that can act to form a
duct. For this example, it can be expressed as a dimension away from the outside
dimension of the fins to the nearest surface.
DTS Digital Thermal Sensor reports a relative die temperature as an offset from TCC
activation temperature.
FSC Fan Speed Control
IHS Integrated Heat Spreader: a component of the processor package used to enhance the
thermal performance of the package. Component thermal solutions interface with the
processor at the IHS surface.
ILM Independent Loading Mechanism provides the force needed to seat the 1356-LGA land
package onto the socket contacts.
LGA1356 socket The processor mates with the system board through this surface mount, 1356-contact
socket.
PECI The Platform Environment Control Interface (PECI) is a one-wire interface that provides
a communication channel between Intel processor and chipset components to external
monitoring devices.
ΨCA Case-to-ambient thermal characterization parameter (psi). A measure of thermal
solution performance using total package power. Defined as (TCASE – TLA) / Total
Package Power. Heat source should always be specified for Ψmeasurements.
ΨCS Case-to-sink thermal characterization parameter. A measure of thermal interface
material performance using total package power. Defined as (TCASE – TS) / Total
Package Power.
ΨSA Sink-to-ambient thermal characterization parameter. A measure of heatsink thermal
performance using total package power. Defined as (TS– TLA) / Total Package Power.

Intel® Xeon® Processor E5-2400 Product Family 11
Thermal/Mechanical Design Guide
Introduction
§
TCASE The case temperature of the processor measured at the geometric center of the topside
of the IHS.
TCASE_MAX The maximum case temperature as specified in a component specification.
TCC Thermal Control Circuit: Thermal monitor uses the TCC to reduce the die temperature
by using clock modulation and/or operating frequency and input voltage adjustment
when the die temperature is very near its operating limits.
TCONTROL TCONTROL is a static value below TCC activation used as a trigger point for fan speed
control.
TDP Thermal Design Power: Thermal solution should be designed to dissipate this target
power level. TDP is not the maximum power that the processor can dissipate.
Thermal Monitor A power reduction feature designed to decrease temperature after the processor has
reached its maximum operating temperature.
Thermal Profile Line that defines the temperature specification of a processor at a given power level.
TIM Thermal Interface Material: The thermally conductive compound between the heatsink
and the processor case. This material fills the air gaps and voids, and enhances the
transfer of the heat from the processor case to the heatsink.
TLA The measured ambient temperature locally surrounding the processor. The ambient
temperature should be measured just upstream of a passive heatsink or at the fan inlet
for an active heatsink.
TSA The system ambient air temperature external to a system chassis. This temperature is
usually measured at the chassis air inlets.
U A unit of measure used to define server rack spacing height. 1U is equal to 1.75 in, 2U
equals 3.50 in, etc.
Table 1-2. Terms and Descriptions (Sheet 2 of 2)
Term Description

Introduction
12 Intel® Xeon® Processor E5-2400 Product Family
Thermal/Mechanical Design Guide

Intel® Xeon® Processor E5-2400 Product Family 13
Thermal/Mechanical Design Guide
LGA1356 Socket
2LGA1356 Socket
This chapter describes a surface mount, LGA (Land Grid Array) socket intended for
processors in the E5-2400 Product Family Platform. The socket provides I/O, power and
ground contacts. The socket contains 1356 contacts arrayed about a cavity in the
center of the socket with lead-free solder balls for surface mounting on the
motherboard.
The socket has 1356 contacts with 1.016 mm X 1.016 mm pitch (X by Y) in a 43x41
grid array with 21x17 grid depopulation in the center of the array and selective
depopulation elsewhere.
The socket must be compatible with the package (processor) and the Independent
Loading Mechanism (ILM). The design includes a back plate which is a key contributor
in producing a uniform load on the socket solder joints. Socket loading specifications
are listed in Section 4.4.
Figure 2-1. LGA1356 Socket with Pick and Place Cover Removed

LGA1356 Socket
14 Intel® Xeon® Processor E5-2400 Product Family
Thermal/Mechanical Design Guide
Figure 2-2. LGA1356 Socket Contact Numbering (Top View of Socket)

Intel® Xeon® Processor E5-2400 Product Family 15
Thermal/Mechanical Design Guide
LGA1356 Socket
2.1 Board Layout
The land pattern for the LGA1356 socket is 40 mils X 40 mils (X by Y). Note that there
is no round-off (conversion) error between socket pitch (1.016 mm) and board pitch
(40 mil) as these values are equivalent.
In general, metal defined (MD) pads perform better than solder mask defined (SMD)
pads under thermal cycling, and SMD pads perform better than MD pads under
dynamic stress. At this time, complete recommendations for pad definition and pad size
do not exist for the LGA1356 socket. See Section 2.9 for more information on pad
definition and pad size.
Figure 2-3. LGA1356 Socket Land Pattern (Top View of Board)

LGA1356 Socket
16 Intel® Xeon® Processor E5-2400 Product Family
Thermal/Mechanical Design Guide
2.2 Attachment to Motherboard
The socket is attached to the motherboard by 1356 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 the LGA1366 Socket
Validation Reports, and the LGA1356 Addendum.
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 1356 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
Figure 2-4. Attachment to Motherboard
LGA1356
Socket
ILM

Intel® Xeon® Processor E5-2400 Product Family 17
Thermal/Mechanical Design Guide
LGA1356 Socket
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.
2.3.3 Contacts
Base material for the contacts is high strength copper alloy.
For the area on socket contacts where processor lands will mate, there is a 0.381 μm
[15 μinches] minimum gold plating over 1.27 μm [50 μinches] minimum nickel
underplate.
No contamination by solder in the contact area is allowed during solder reflow.
2.3.4 Pick and Place Cover
The cover provides a planar surface for vacuum pick up used to place components in
the Surface Mount Technology (SMT) manufacturing line. The cover remains on the
socket during reflow to help prevent contamination during reflow. The cover can
withstand 260 °C for 40 seconds (typical reflow/rework profile) and the conditions
listed in the LGA1366 Socket Validation Reports, and LGA1356 Addendum, without
degrading. Reports are available from socket suppliers listed in Appendix A.
As indicated in Figure 2-5, the Pick and Place cover remains on the socket during ILM
installation. Use of the ILM cover can mitigate against bent socket contacts associated
with reinstalling the Pick and Place cover. A cover should remain on whenever possible
to help prevent damage to the socket contacts. See Section 3.2 and Section 3.3 for
additional information on the ILM cover.
Pick and Place cover retention must be sufficient to support the socket weight during
lifting, translation, and placement (board manufacturing), and during board and
system shipping and handling.
Pick and Place covers are designed to be interchangeable between socket suppliers. As
indicated in Figure 2-5, a Pin1 indicator on the Pick and Place cover provides a visual
reference for proper orientation with the socket.
Figure 2-5. Pick and Place Cover
ILM Installation
Pick and
Place Cover
Pin 1
ILM cover

LGA1356 Socket
18 Intel® Xeon® Processor E5-2400 Product Family
Thermal/Mechanical Design Guide
2.4 Package Installation / Removal
As indicated in Figure 2-6, access is provided to facilitate manual installation and
removal of the package.
To assist in package orientation and alignment with the socket:
• The package Pin1 triangle and the socket Pin1 chamfer provide visual reference for
proper orientation.
• The package substrate has orientation notches along two opposing edges of the
package, offset from the centerline. The socket has two corresponding orientation
posts to physically prevent mis-orientation of the package. These orientation
features also provide initial rough alignment of package to socket.
• As shown in Figure 2-7, the package substrate has a “-2” mark near the orientation
notch on the Pin 1 side. Similarly, space has been reserved for a “-2” mark on the
motherboard in the Board Keepin / Keepout Zones in Figure B-1 and Figure B-2.
These matching marks help prevent system assemblers from installing the
incorrect processor into the socket.
• The socket has alignment walls at the four corners to provide final alignment of the
package.
See Appendix D for information regarding a tool designed to provide mechanical
assistance during processor installation and removal.
.
Figure 2-6. Package Installation / Removal Features

Intel® Xeon® Processor E5-2400 Product Family 19
Thermal/Mechanical Design Guide
LGA1356 Socket
2.4.1 Socket Standoffs and Package Seating Plane
Standoffs on the bottom of the socket base establish the minimum socket height after
solder reflow and are specified in Appendix C.
Similarly, a seating plane on the topside of the socket establishes the minimum
package height. See Section 3.2 for the calculated IHS height above the motherboard.
2.5 Durability
The socket must withstand 30 cycles of processor insertion and removal. The max
chain contact resistance from Table 4-4 must be met when mated in the 1st and 30th
cycles.
The socket Pick and Place cover must withstand 15 cycles of insertion and removal.
2.6 Markings
There are three markings on the socket:
• LGA1356: Font type is Helvetica Bold - minimum 6 point (2.125 mm).
• Manufacturer's insignia (font size at supplier's discretion).
• Lot identification code (allows traceability of manufacturing date and location).
All markings must withstand 260 °C for 40 seconds (typical reflow/rework profile)
without degrading, and must be visible after the socket is mounted on the
motherboard.
LGA1356 and the manufacturer's insignia are molded or laser marked on the side wall.
Figure 2-7. Package and Board Enabling Mark (-2)

LGA1356 Socket
20 Intel® Xeon® Processor E5-2400 Product Family
Thermal/Mechanical Design Guide
2.7 Component Insertion Forces
Any actuation must meet or exceed SEMI S8-95 Safety Guidelines for Ergonomics/
Human Factors Engineering of Semiconductor Manufacturing Equipment, example Table
R2-7 (Maximum Grip Forces). The socket must be designed so that it requires no force
to insert the package into the socket.
2.8 Socket Size
Socket information needed for motherboard design is given in Appendix C.
This information should be used in conjunction with the reference motherboard keepout
drawings provided in Appendix B to ensure compatibility with the reference thermal
mechanical components.
2.9 LGA1356 Socket NCTF Solder Joints
Intel has defined selected solder joints of the socket as non-critical to function (NCTF)
for post environmental testing. The processor signals at NCTF locations are typically
redundant ground or non-critical reserved, so the loss of the solder joint continuity at
end of life conditions will not affect the overall product functionality. Figure 2-8
identifies the NCTF solder joints.
Since corner pads are often more susceptible to solder joint damage, NCTF locations
are often placed in the corners. When possible, larger pads may be chosen at NCTF
locations to further mitigate against solder joint damage. At this time, complete
recommendations for pad definition and pad size do not exist at NCTF locations. CTF
and NCTF locations are 18mil solder mask defined on Intel reference designs.