1、ANSI/VITA 58.0 VITA PO Box 19658, Fountain Hills, AZ 85269 PH: 480-837-7486 Email: URL: http:/ Approved American National Standard ANSI/VITA 48.1 Mechanical Specification for Microcomputers Using REDI Air Cooling Abstract This standard defines the mechanical requirements that are needed to insure t
2、he mechanical interchangeability of air cooled 3U and 6U plug-in units and define the features required to achieve 2 Level Maintenance compatibilly. Approved July 2010 American National Standards Institute, Inc. American National Standard Approval of an American National Standard requires verificati
3、on 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 affected inte
4、rests. 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; their exist
5、ence 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 in no circ
6、umstances 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 to the secre
7、tariat 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 CAUTION NOTICE: This American National Standard may be revised or withdrawn at any time.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 withdraw thi
8、s standard. Purchases of American National Standards may receive current information on all standard by calling or writing the American National Standards Institute. NOTE The users attention is called to the possibility that compliance with this standard may require use of an invention covered by pa
9、tent rights. By publication of this standard, no position is taken with respect to the validity of this claim 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 te
10、rms and conditions to applicants desiring to obtain such a license. Details may be obtained from the standards developer. Published by VMEbus International Trade Association (VITA) PO Box 19658, Fountain Hills, AZ 85269 Copyright 2010 by VMEbus International Trade Association All rights reserved. Pe
11、rmission of the publisher is required to reproduce this document or any part of it. Printed in the United States of America - R1.0 ISBN 1-885731-61-2 ANSI/VITA 48.1-2010 Page 3 of 48 Working Group During the development of this standard, the working group membership included: Name Organization Statu
12、s 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 Corporation Sponsor 6 Richard Hodges Parker Sponsor 7 Dan G
13、olden 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 Computing Participant 12 David Compston Radstone Participant 13 Gerard Drewek
14、 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 18 Frank Hom APW Electronic Solutions Participant 19 Andreas Lenkisch
15、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 VITA Participant 25 Bob Sullivan Hybricon Corporation Participant 26 Bruc
16、e 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 Participant 30 Ken Boyette Critia Computer, Inc. Observer 31 Michael Munr
17、oe Bustronics Observer 32 Elwood Parsons Standard Consultant Observer 33 Mac Rush Motorola Computer Group Observer ANSI/VITA 48.1-2010 Page 4 of 48 Comments, Corrections, and/or Additions Anyone wishing to provide comments, corrections and/or additions to this standard please direct them to the VITA
18、 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 Product Directories, VME Handbooks, or general information on the VME mark
19、et, please contact the VITA office at the address or telephone number given on the front cover. ANSI/VITA 48.1-2010 Page 5 of 48 Table of Contents 1 Scope7 2 Purpose.7 3 Intellectual Property 7 4 References8 4.1 Terminology.8 4.1.1 Abbreviations8 4.1.2 2 Level Maintenance (2LM)9 4.1.3 Special word u
20、sage 9 5 Circuit Board .11 5.1 Circuit Board Sizes 11 5.2 Conductive Elements and Plug-in Unit Frame.11 5.3 Circuit Board Commonality11 6 Plug-in unit description13 7 Plug-in units 20 7.1 Plug-in unit height20 7.2 Plug-in unit depth.27 7.3 Plug-in unit thickness and plug-in unit cover/PCB relationsh
21、ip .27 7.4 Keying and guide pin/guide socket28 7.5 Primary side cover.28 7.6 Secondary side cover 28 7.7 Plug-in unit insertion/extraction features .29 8 Guidance on cooling .30 9 Position of plug-in unit mounted connectors and backplane mounted connectors .31 9.1 Position of connectors on the plug-
22、in units31 9.2 Position of backplane mounted connectors.31 9.3 Backplane Rigidity .35 9.4 Dimensions35 10 Sub-rack41 11 Filler panels/slot blockers45 11.1 Air-cooled systems.45 12 EMC 46 13 Two Level Maintenance (2LM) considerations .47 Table of Figures Figure 1. 3U PCB size. .12 Figure 2. 6U PCB si
23、ze. .12 Figure 3. Representative configuration of 3U air-cooled plug-in units. 14 Figure 4. Representative configuration of 3U air-cooled plug-in units alternate implementation.15 Figure 5. Representative configuration of 6U air-cooled plug-in units. 16 Figure 6. Representative configuration of 6U a
24、ir-cooled plug-in units alternate implementation17 Figure 7. Example of connector protection applied to a 6U plug-in unit. 18 Figure 8. Comparison of 6U plug-in units, without and with connector protection. .19 Figure 9. Envelope for 3U air cooled plug-in with PCB using primary side retainers.21 Fig
25、ure 10. Envelope for 3U air cooled plug-in with PCB using secondary side retainers. 22 Figure 11. Envelope for 6U air cooled plug-in with PCB using primary side retainers23 Figure 12. Envelope for 6U air cooled plug-in with PCB using secondary side retainers. 24 Figure 13. Plug-in unit cover-to-PCB
26、relationship.26 Figure 14. Recommended direction for airflow in the chassis .30 Figure 15. 3U backplane primary side view. .32 Figure 16. 6U backplane with plug-in units on 1.00 in. centers, primary side view.33 Figure 17. 3U and 6U backplane Assemblies.34 Figure 18. 0.80 in. plug-in unit pitch back
27、plane populated with 0.80 in. pitch.36 Figure 19. 0.85 in. plug-in unit pitch backplane populated with 0.80 and 0.85 in. pitch plug-in units. 37 ANSI/VITA 48.1-2010 Page 6 of 48 Figure 20A. 1.00 in. plug-in unit pitch backplane populated with 0.80, 0.85 and 1.00 in. pitch plug-in units. .38 Figure 2
28、0B. 1.00 in. plug-in unit pitch backplane populated with 0.80, 0.85 and 1.00 in. pitch plug-in units. .39 Figure 21. Board, connector, and backplane relationship. 40 Figure 22. Critical sub-rack dimensions for 3U air-cooled plug-in units.43 Figure 23. Critical sub-rack dimensions for 6U air-cooled p
29、lug-in units.44 Figure 24. Slot blocker for air cooled applications. 6U, 1.00 in. pitch plug-in unit shown. .45 Table of Tables Table 1. Matrix of maximum cover thickness available for connector protection18 Table 2. Variable table for plug-in unit envelope dimensions 25 Table 3. Plug-in unit width
30、as a function of plug-in unit pitch. 27 Table 4. Variable table for backplane PCB. 33 Table 5. Variable table for backplane assemblies. 35 Table 6. Compatibility matrix for plug-in units into sub-racks of varying pitch. 41 Table 7. Variable table for the air cooled sub-rack figures.42 ANSI/VITA 48.1
31、-2010 Page 7 of 48 1 Scope VITA 48.1 defines a detailed mechanical implementation for air-cooling (i.e., cooling air flowing over the components) applications applied to PCBs/plug-in units defined in VITA 46. This specification gives the dimensions of associated plug-in units together with applicabl
32、e 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 increased slot pitch and secondary side utilization. In addition, both Type 1 and Type 2 plug-in units will a
33、lso incorporate features to enhance thermal performance and improve structural durability. The main difference between Type 1 and Type 2 plug-in units is 2 Level Maintenance compatibility (see section 4.1.2). Type 1 plug-in units will be compatible with 2 Level Maintenance environments. Type 2 plug-
34、in units will have one or more of the required design features absent and therefore will not be fully compatible with 2 Level Maintenance environments. The air cooled implementations described in this specification are targeted for 3U and 6U form factor plug-in units with PCB and backplane connector
35、s defined in VITA 46. However, in addition to backplane connectors on 0.80 in. centers, VITA 48.1 will also define implementations with backplane connectors on 0.85 and 1.00 in. centers.! 2 Purpose The purpose of this specification is to define the critical dimensions for air cooled plug-in units re
36、quired 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 both the thermal and structural characteristics of a plug-in unit. Th
37、e 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 family of standards, the users attention is called to the possibility
38、 that compliance with this standard, ANSI/VITA 48.1, Mechanical Specification for Microcomputers Using REDI Air Cooling, may require use of one or more inventions covered by patent rights. By publication of this standard, no position is taken with respect to the validity of such claims or of any pat
39、ent 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 such a license. Details may be obtained from the standards developer. A
40、NSI/VITA 48.1-2010 Page 8 of 48 4 References The following publications shall be used in conjunction with this specification. When they are superseded by an approved revision, the revision shall apply IEEE Std 1101.1 1998, IEEE Standard for Mechanical Core Specifications for Microcomputers Using IEC
41、 603-2 Connectors IEEE Std 1101.2 -1992 (2002), IEEE Standard for Mechanical Core Specifications for Conduction-Cooled Eurocards IEEE Std 1101.10-1996 (2002),IEEE Standard for Additional Mechanical Specifications for Microcomputers Using the IEEE Std 1101.1-1991 Equipment Practice ANSI/VITA 46.0-200
42、7, American National Standard for VPX Baseline Standard ANSI/VITA 47-2005, Environments, Design and 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
43、 for a Common Mezzanine Card Family: CMC ANSI/VITA 42.0-2008, XMC!4.1 Terminology 4.1.1 Abbreviations The following abbreviations are used in this specification: ATR: Air Transport Rack CGCL: Card guide centerlines CPCL: “comb” pattern centerlines EMC: Electromagnetic Compatibility ESD: Electrostati
44、c Discharge F: feasible FPW: Front panel width FwR: Feasible with risk GND: Ground GPCL: 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-hole over backplane-to-datum KHCL2: guide/key pin hole
45、center lines hole-to-hole over backplane length KHE1: guide/key pin hole center line to edge of backplane bottom KHE2: guide/key pin hole center line to edge of backplane top LRSCL: Lever retaining screw centerlines MHCL: mounting holes centerline-to-centerline MHE: mounting hole to edge mm: millime
46、ter NF: Not feasible NRE: Non-recurring Engineering PCB: Printed Circuit Board PMC: PCI Mezzanine Card PS: primary side of PCB to front of plug-in unit REDI: Ruggedized Enhanced Design Implementation SS: Primary side of PCB to back of plug-in unit ANSI/VITA 48.1-2010 Page 9 of 48 U: Units of 44.45 m
47、m (1.75 in) See ANSI/EIA-310D-1992 and IEC 297-1 (1986) 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. 4.1.2 2 Level Maintenance (2LM) Given there are no external s
48、tandard that establishes specific plug-in unit design requirements for 2 Level Maintenance compatibility, for the purposes of this specification, all Type 1 plug-in units will be defined as being 2 Level Maintenance compatible. Type 1 plug-in units will possess the following attributes: Mechanical p
49、rotection and handling robustness afforded by covers 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. 4.1.3 Special word usage To avoid confusion and to make very clear what the requirements for compliance are, many of the paragraphs in this specification are labeled with keywords that in
