LGA771 Socket Mechanical Design Guide November, 2006 Reference Number: 313871-002
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Contents 1 Introduction................................................................................................................. 7 1.1 Document Goals and Scope .................................................................................. 7 1.1.1 LGA771 Socket Overview .......................................................................... 7 1.1.2 Document Goals....................................................................................... 7 1.1.3 Important Remarks ..................
Figures 3-1 3-2 5-1 A-1 A-2 A-3 A-4 A-5 A-6 A-7 A-8 A-9 A-10 A-11 A-12 A-13 Cross-sectional view of Package / Socket stackup height1 .......................................15 Definition of R ...................................................................................................17 Flow Chart of Knowledge-Based Reliability Evaluation Methodology...........................21 LGA Socket Assembly Drawing (Sheet 1 of 4) ........................................................
Revision History Revision Description Date 001 • Initial release of the document.
LGA 771 Socket Mechanical Design Guide
Introduction 1 Introduction 1.1 Document Goals and Scope 1.1.1 LGA771 Socket Overview This document describes a surface mount, LGA (Land Grid Array) socket intended for the Dual-Core Intel® Xeon® Processor 5000 Sequence Family for Servers and Workstations. The socket provides I/O, power and ground contacts. The socket contains 771 contacts arrayed about a cavity in the center of the socket with solder balls for surface mounting with the motherboard.
Introduction 1.2 Terminology Term 1.3 Description LGA771 Socket Processor in the 771-land package mates with the system board through a surface mount, 771-pin, LGA (land grid array) socket. LGA771-Land LGA771 Package Processors in the 771-Land package are available in a Flip-Chip Land Grid Array package technology, consisting of a processor core mounted on a substrate with an integrated heat spreader (IHS). This packaging technology employs a 1.09 mm x 1.17 mm pitch for the substrate lands.
Assembled Component and Package Description 2 Assembled Component and Package Description The LGA771 Socket dimensions and characteristics must be compatible with that of the processor package and related assembly components. Processors using Flip-Chip Land Grid Array package technology are targeted to be used with the LGA771 socket. The assembled component may consist of a cooling solution (heatsink, fan, clips, and retention mechanism), and processor package.
Assembled Component and Package Description 10 LGA 771 Socket Mechanical Design Guide
Mechanical Requirements 3 Mechanical Requirements 3.1 Attachment The socket will be tested against the mechanical shock and vibration requirements listed in Section 5 under the expected use conditions with a heatsink and retention mechanism attached under the loading conditions outlined in Section 3.6, and the processor datasheet. The socket will only be attached by the 771 contact solder balls to the motherboard. There are no additional external methods (i.e. screw, extra solder, adhesive, etc.
Mechanical Requirements operating temperature, while mounted on an FR4-type motherboard material. The creep properties of the material must be such that the mechanical integrity of the socket is maintained for the use condition outlined in Section 5. The color of the socket housing will be dark as compared to the solder balls to provide the contrast needed for surface-mount (SMT) equipment pick and place vision systems.
Mechanical Requirements 3.2.1.4.2 Lot Traceability Each socket will be marked with a lot identification code to allow traceability of all components, date of manufacture (year and week), and assembly location. The mark must be placed on a surface that is visible when mounted on the motherboard. 3.2.1.5 Contacts The socket has a total of 771 contacts, with 1.09 mm X 1.
Mechanical Requirements The stiffener plate is made of stainless steel SUS 301. The stiffener plate provides the interface to the load lever and the load plate and creates the primary stiffening element to react to the load generated by the load plate. 3.2.3 Pick and Place Cover The pick and place cover is a dual purpose removable component common to the LGA771 socket. The cover’s primary purpose is to provide a planar surface at least 20 mm in diameter and compatible with SMT placement systems.
Mechanical Requirements 3.5 Package/Socket Stackup Height Table 3-1 provides the stackup height of the processor package and LGA771 socket. Table 3-1. Intel® Xeon® 5000 Sequence Package and Socket Stackup Height Processor Dual-Core Intel® Xeon® Processor 5000 Series Integrated Stackup Height 1 (mm) From Top of Board to Top of IHS 7.628 - 8.120 Dual-Core Intel® Xeon® Processor 5100 Series 7.693 - 8.155 Quad-Core Intel® Xeon® Processor 5300 Series 7.604 - 8.124 Notes: 1. Preliminary Guidance.
Mechanical Requirements Table 3-2. Socket Loading Specifications Parameter Static Compressive Load Dynamic Compressive Load Transient Bend Limits Board Thickness R10 Apply for all board thickness from 1.57 mm ( 0.062” ) to 2.54 mm ( 0.100” ) 25 mm 45 mm 80 18 311 70 N lbf NA NA NA 311 N (max static compressive load) + 222 N dynamic loading 70 lbf (max static compressive load) + 50 lbf dynamic loading N 750 με 1.57 mm 0.062” NA Min NA Max 2.16 mm 0.
Mechanical Requirements Figure 3-2.
Mechanical Requirements 18 LGA 771 Socket Mechanical Design Guide
Electrical Requirements 4 Electrical Requirements Table 4-1 provides the LGA771 Socket electrical requirements. Socket electrical requirements are measured from the socket-seating plane of the processor to the component side of the PCB to which it is attached. All specifications are maximum values (unless otherwise stated) for a single socket contact, but includes effects of adjacent contacts where indicated. Table 4-1.
Electrical Requirements 20 LGA 771 Socket Mechanical Design Guide
Environmental Requirements 5 Environmental Requirements Design, including materials, shall be consistent with the manufacture of units that meet the following environmental reference points. The reliability targets in this section are based on the expected field use environment for a server product. The test sequence for new sockets will be developed using the knowledge-based reliability evaluation methodology, which is acceleration factor dependent.
Environmental Requirements Table 5-1. Use Conditions Environment Use Environment Speculative Stress Condition Example Use condition Example 7 Year stress equivalent Example 10 Year stress equivalent Slow small internal gradient changes due to external ambient (temperature cycle or externally heated) Fast, large gradient on/off to max operating temp.
Environmental Requirements 5.1 Solvent Resistance Requirement: No damage to ink markings if applicable. EIA 364-11A. 5.2 Durability Use per EIA-364, test procedure 09. Measure contact resistance when mated in 1st and 30th cycles. The package should be removed at the end of each de-actuation cycle and reinserted into the socket. The socket’s pick-and-place cover must be able to be inserted and removed from the socket at least 30 times.
Environmental Requirements 24 LGA 771 Socket Mechanical Design Guide
Mechanical Drawings A Mechanical Drawings The following table lists the mechanical drawings included in this section. These drawings refer to the LGA771 socket. Note: Intel reserves the right to make changes and modifications to the design as necessary. Drawing Description LGA771 Socket Assembly Drawing Page Number 27-30 LGA771 Socket Motherboard Footprint -1 31-37 LGA771 Socket Footprint 38-39 See figures beginning on following page.
Mechanical Drawings Figure A-1.
Mechanical Drawings Figure A-2.
Mechanical Drawings Figure A-3.
Mechanical Drawings Figure A-4.
Mechanical Drawings Figure A-5.
Mechanical Drawings Figure A-6.
Mechanical Drawings Figure A-7.
Mechanical Drawings Figure A-8.
Mechanical Drawings Figure A-9.
Mechanical Drawings Figure A-10.
Mechanical Drawings Figure A-11.
Mechanical Drawings Figure A-12.
Mechanical Drawings Figure A-13.