1、 VITA PO Box 19658, Fountain Hills, AZ 85269 PH: 480-837-7486 Email: URL: http:/ Approved American National Standard ANSI/VITA 48.2 Mechanical Specifications for Microcomputers Using REDI Conduction Cooling Applied to VITA VPX Abstract To define the mechanical requirements that are needed to ensure
2、 the mechanical interchangeability of conduction cooled 3U and 6U plug-in units and defines the features required to achieve 2 Level Maintenance compatibility. Approved July 2010 American National Standards Institute, Inc. American National Standard Approval of an American National Standard requires
3、 verification by ANSI that the requirements for due process, consensus, and other criteria for approval have been met by the standards developer. Consensus is established when, in the judgment of the ANSI Board of Standards Review, substantial agreement has been reached by directly and materially af
4、fected interests. Substantial agreement means much more than a simple majority, but not necessarily unanimity. Consensus requires that all views and objections be considered, and that a concerted effort be made toward their resolution. The use of American National Standards is completely voluntary;
5、their existence does not in any respect preclude anyone, whether he has approved the standards or not, from manufacturing, marketing, purchasing, or using products, processes, or procedures not conforming to the standards. The American National Standards Institute does not develop standards and will
6、 in no circumstances give an interpretation of any American National Standard. Moreover, no person shall have the right or authority to issue an interpretation of an American National Standard in the name of the American National Standard Institute. Requests for interpretations should be addressed t
7、o the secretariat or sponsor whose name appears on the title page of this standard. CAUTION NOTICE: This American National Standard may be revised or withdrawn at any time. The procedures of the American National Standards Institute require that action be taken periodically to reaffirm, revise, or w
8、ithdraw this standard. Purchases of American National Standards may receive current information on all standard by calling or writing the American National Standards Institute. Published by VMEbus International Trade Association (VITA) PO Box 19658, Fountain Hills, AZ 85269 Copyright 2010 by VMEbus
9、International Trade Association All rights reserved. Permission of the publisher is required to reproduce this document or any part of it. Printed in the United States of America - R1.0 ISBN 1-885731-60-4 ANSI/VITA 48.2-2010 Page 3 of 53 Working Group During the development of this standard working
10、group membership included: Name Organization Status 1 Randy Banton Mercury Computer Systems Sponsor 2 Stewart Dewar Curtiss-Wright Controls Embedded Computing Sponsor 3 Jim Robles The Boeing Company Sponsor 4 Michael Benjamin Parker Hannifin Corporation Sponsor 5 Rex Harvey Parker Hannifin Corporati
11、on Sponsor 6 Richard Hodges Parker Hannifin Corporation Sponsor 7 Dan Golden The Boeing Company Sponsor 8 Ivan Straznicky Curtiss-Wright Controls Embedded Computing Sponsor 9 Steve Belvin ISBi Participant 10 Adam Bloch EATON Aerospace Participant 11 Gorky Chin Curtiss-Wright Controls Embedded Comput
12、ing Participant 12 David Compston Radstone Participant 13 Gerard Drewek General Dynamics Participant 14 Doug DuBois L-3 Communications Participant 15 Chris Eckert SBS technologies, Inc. Participant 16 Mark Heslep MITRE Corporation Participant 17 Itzhak Hirshtal Elta Electronic Industries Participant
13、 18 Frank Hom APW Electronic Solutions Participant 19 Andreas Lenkisch Schroff GmbH Participant 20 Charles Linquist Dawn VME Products, Inc. Participant 21 David McCallum Molex Participant 22 Bob Patterson Tyco Electronics Participant 23 Andrew Reddig TEK Microsystems Participant 24 John Rynearson VI
14、TA Participant 25 Bob Sullivan Hybricon Corporation Participant 26 Bruce Thomas Curtiss-Wright Controls Embedded Computing Participant 27 Michael Thompson Pentair Electronic Packaging Participant 28 Mike Biemer Northrop Grumman Corporation Participant 29 Scott Goedeke Northrop Grumman Corporation Pa
15、rticipant 30 Ken Boyette Critia Computer, Inc. Observer 31 Michael Munroe Bustronics Observer 32 Elwood Parsons Standard Consultant Observer 33 Mac Rush Motorola Computer Group Observer ANSI/VITA 48.2-2010 Page 4 of 53 Comments, Corrections, and/or Additions Anyone wishing to provide comments, corre
16、ctions and/or additions to this standard please direct them to the VITA Technical Director: John Rynearson, Technical Director VITA PO Box 19658 Fountain Hills, AZ 85269 Ph: 480 837 7486 Email: VSO and Other Standards Should anyone want information on other standards being developed by VSO, VME Pro
17、duct Directories, VME Handbooks, or general information on the VME market, please contact the VITA office at the address or telephone number given on the front cover. ANSI/VITA 48.2-2010 Page 5 of 53 Table of Contents 1 Scope7 2 Purpose 7 3 Intellectual Property 7 4 References .7 4.1 Terminology .8
18、4.1.1 Abbreviations 8 4.1.2 2 Level Maintenance (2LM) 9 4.1.3 Frame vs. Cover .9 4.1.4 Special word usage.9 5 Circuit Board11 5.1 Circuit Board Sizes.11 5.2 Conductive Elements and Plug-in Unit Frame .11 5.3 Circuit Board Commonality 11 6 Plug-in Unit 13 6.1 Optional connector protection 17 6.2 Plug
19、-in Unit.18 6.3 Plug-in unit height 19 6.4 Plug-in unit depth .19 6.5 Plug-in unit thickness and plug-in unit frame, cover and PCB relationship24 6.6 Retainer location 27 6.7 Additional retainer considerations 27 6.8 Keying and guide pin/socket 28 6.9 Primary side cover .29 6.10 Secondary side cover
20、 .29 6.11 Plug-in unit insertion/extraction features 29 7 Guidance on cooling .37 8 Position of plug-in unit mounted connectors and backplane mounted connectors 38 8.1 Position of connectors on the plug-in units 38 8.2 Position of backplane mounted connectors .38 8.3 Backplane Rigidity38 8.4 Dimensi
21、ons 39 9 Sub-rack .48 10 Filler panels/slot blockers 52 11 EMC.52 12 Two Level Maintenance (2LM) considerations .52 Table of Figures Figure 1. 3U and 6U board size12 Figure 2. Representative configurations of 3U conduction cooled plug-in units, primary side retainers.15 Figure 3. Representative conf
22、igurations of 6U conduction cooled plug-in units on 1.00 in. centers, primary side retainers. 16 Figure 4. Example of connector protection applied to a 6U plug-in unit. 17 Figure 5. Comparison of 6U plug-in units, without and with connector protection18 Figure 6. Envelope dimensions for a Type 1, 3U
23、 plug-in unites primary side retainers. .20 Figure 7. Envelope dimensions for a Type 1, 6U plug-in units- primary side retainers. .21 Figure 8. Envelope dimensions for a Type 1, 3U plug-in units secondary side retainers22 Figure 9. Envelope dimensions for a Type 1, 6U plug-in units secondary side re
24、tainers23 Figure 10. Dimensions shown are applicable to both 3U and 6U form factor plug-in units. .26 Figure 11. Plug-in unit insertion process and features in the extraction/insertion lever .31 Figure 12. Plug-in extraction process and features in the extraction/insertion lever and sub-rack. .32 Fi
25、gure 13. View of sub-rack showing features for insertion and extraction. .33 Figure 14. 6U sub-rack features required for insertion. 34 Figure 15. 3U sub-rack features required for insertion. 35 Figure 16. 6U features for alternate insertion/extraction Lever. 36 ANSI/VITA 48.2-2010 Page 6 of 53 Figu
26、re 17. Plug-in unit to sub-rack thermal interface37 Figure 18. 3U backplane primary side view.40 Figure 19. 6U backplane primary side view.41 Figure 20. 3U and 6U backplane assemblies primary side view. 42 Figure 21. 0.80 in. plug-in unit pitch backplane populated with 0.80 in. pitch plug-in units.
27、.44 Figure 22. 0.85 in. plug-in unit pitch backplane populated with 0.80 and 0.85 in. pitch plug-in units.45 Figure 23. 1.00 in. plug-in unit pitch backplane populated with 0.80, 0.85 and 1.00 in. pitch plug-in units. .46 Figure 24. Board, connector, and backplane relationship. .47 Figure 25. Critic
28、al sub-rack dimensions for 3U plug-in units primary and secondary side retainers. 49 Figure 26 Critical sub-rack dimensions for 6U plug-in units primary and secondary side retainers. .50 Table of Tables Table 1. Matrix of maximum cover thickness available for connector protection. .17 Table 2. Varia
29、ble table for plug- in units; primary side retainers. .24 Table 3. Variable table for plug- in units; Secondary side retainers. 24 Table 4. Plug-in unit width as a function of plug-in pitch. .25 Table 5. Variable table for backplane PCB.43 Table 6. Variable table for backplane assemblies. .43 Table
30、7. Compatibility matrix for plug-in units into sub-racks of varying pitch. .48 Table 8. Variable values for sub-rack figures. 51 ANSI/VITA 48.2-2010 Page 7 of 53 1 Scope VITA 48.2 defines a detailed mechanical implementation for conduction cooling applications applied to PCBs/plug-in units defined i
31、n VITA 46. This specification gives the dimensions of associated plug-in units together with applicable detail dimensions of key sub-rack interfaces. Two types of plug-in units are defined in this specification. Both Types of plug-in units defined in this specification will take advantage of increas
32、ed slot pitch and utilization of the secondary side. In addition, both Type 1 and Type 2 plug-in units will also incorporate features to enhance thermal performance and improve structural durability. !The main difference between Type 1 and Type 2 plug-in units is that the Type 1 plug-in units will b
33、e compatible with 2 Level Maintenance environments (see section 4.1.2). Type 2 plug-in units may have one or more covers absent and therefore will not be fully compatible with 2 Level Maintenance environments. The conduction cooled implementations described in this specification are targeted for 3U
34、and 6U form factor plug-in units with PCB and backplane connectors defined in VITA 46. However, in addition to backplane connectors on 0.80 in. centers, VITA 48 will also define implementations with backplane connectors on 0.85 and 1.00 in. centers. 2 Purpose The purpose of this specification is to
35、define the critical dimensions for conduction cooled plug-in units required to ensure the mechanical interchangeability of plug-in units, achieve enhanced packaging density by allowing increased utilization of the secondary side of the PCB and provide sufficient volume for features that can improve
36、both the thermal and structural characteristics of a plug-in unit. The requirements for Type 1 and Type 2 plug-in units will be defined. Also defined are the features/capabilities necessary for Type 1 plug-in units to achieve 2 Level Maintenance compatibility. !3 Intellectual Property In the VITA 48
37、 family of standards, the users attention is called to the possibility that compliance with the “ANSI/VITA 48.1, Mechanical Specification for Microcomputers Using REDI Air Cooling” standard may require use of one or more inventions covered by patent rights. By publication of this standard, no positi
38、on is taken with respect to the validity of such claims or of any patent rights in connection therewith. The patent holder has, however, filed a statement of willingness to grant a license under these rights on reasonable and nondiscriminatory terms and conditions to applicants desiring to obtain su
39、ch a license. Details may be obtained from the standards developer.ANSI/VITA 48.2-2010 Page 8 of 53 References The following publications shall be used in conjunctions with this specification. When they are superseded by an approved revision, the revision shall apply ANSI/VITA 42.0-2008, XMC IEEE St
40、d 1101.1 1998, IEEE Standard for Mechanical Core Specifications for Microcomputers Using IEC 603-2 Connectors IEEE Std 1101.2 -1992, IEEE Standard for Mechanical Core Specifications for Conduction-Cooled Eurocards ANSI/VITA 46.0-2007, VPX Baseline Standard ANSI/VITA 47-2005, Environments, Design and
41、 Construction, Safety, and Quality for Plug-In Units ANSI/VITA 48.0, Mechanical Specification for Microcomputers Using Ruggedized Enhanced Design Implementation (REDI) IEEE Std 1386-2001, IEEE Standard for a Common Mezzanine Card Family: CMC !ANSI/VITA 20 -2001 (2005) American National Standard for
42、Conduction Cooled PMC !3.1 Terminology 3.1.1 Abbreviations The following abbreviations are used in this specification: ATR: Air Transport Rack (Austin Trumbull Radio) EMC: Electromagnetic Compatibility ESD: Electrostatic Discharge F: Feasible FwR: Feasible with Risk GND: Safety Ground GPCL: guide pi
43、n-to-guide pin centerlines HP: Horizontal Pitch of 5.08 mm (See IEEE Std 1101.1-1991) in.: inch I/O: Input/Output KHCL1: guide/key pin hole center lines hole-to-datum KHCL2: guide/key pin hole center lines hole-to-hole over backplane length KHE1: guide/key pin hole center line to edge of backplane b
44、ottom KHE2: guide/key pin hole center line to edge of backplane top MHCL: mounting holes centerline-to-centerline mm: Millimeter NF: Not Feasible NRE: Non-recurring engineering PCB: Printed Circuit Board PIUW: plug-in unit width PMC: PCI Mezzanine Card PS: primary side of PCB to front of plug-in uni
45、t PSRW: primary side of PCB to outer edge of relaxed retainer PSTI: primary side of PCB to thermal interface REDI: Ruggedized Enhanced Design Implementation SS: primary side of PCB to back of plug-in unit SW: Slot width U: Units of 44.45 mm (1.75 in) See ANSI/EIA-310D-1992 and IEC 297-1 (1986) ANSI/
46、VITA 48.2-2010 Page 9 of 53 XMC: An evolution of the PMC mezzanine card that includes a new connector and the electrical signals necessary for switched communications between the mezzanine card and its carrier. 3.1.2 2 Level Maintenance (2LM) Given there are no external standards that establish the
47、specific plug-in unit design requirements for 2 Level Maintenance compatibility, for the purposes of this specification, Type 1 plug-in units are 2 Level Maintenance compatible. Type 1 plug-in units will possess the following attributes: Mechanical protection and handling robustness afforded by cove
48、rs Compliance with the ESD susceptibility requirements of ANSI/VITA 47 It follows, by definition, that Type 2 plug-in units may not fully posses all of the required design attributes and therefore may not be 2 Level Maintenance compatible. 3.1.3 Frame vs. Cover For conduction cooled applications, pl
49、ug-in units can use a frame to conduct heat from components to the edge of the plug-in unit where it is transferred into the sub-rack. The frame is present primarily for thermal and structural purposes. As a consequence, it may or may not provide adequate ESD protection. For VITA 48.2, a cover provides ESD protection by preventing ESD pulses from reaching components. A cover can be used in-lieu of a frame or in conjunction with a frame. This can become an important distinction when describing the difference between
