military standard - · pdf filemil -std. 275e 51 ikrew!wr [?/,4 superseding mil -std -275d 26...

MIL -STD. 275E51 Ikrew!wr [?/,4
SUPERSEDINGMIL - STD - 275D26 APRIL 1978MIL : STD -14953 AUGUST 1973
MILITARY STANDARD
PRINTED WIRINGFOR ELECTRONIC EQUIPMENT
Downloaded from http://www.everyspec.com

MI L- ST D-275E31 December 198L
DEPARTMENT Of OEFENSEWashington, OC 20301
Printed d Iring for Electronic Equipment
MI L-sTo-275E
1. This Military Standard is approved for use by all Departments and Agencies ofthe Department of Defense.
2. Beneficial comments (recommendations, additions, deletions) and any pertinentdata which may be of use in improving this document should be addressed to: NavalElectronic Systems Command, AlTN: EL EX-8111, Washington, OC 20363, by using theself-addressed Standardization Oocument Improvement Proposal [00 Form 1426) appearingat the end of this document, or by letter.
i{

f41L. sTD-27s E
31 Ikcembcr 198L
CONTENTS
Paragraph 1. SCOPE ---------------------------------------------1.1 Puro Ose -----------------------------------------1.2 Class ificati on----------------------------------
2. QfFERENCCO DOCUMENT S ------------------------------
3. DE FINITl ON S-------------------------------------:-
4. GENERAL REQUIRE ME NT S ------------------------------4.1 Oesign feature s ---------------------------------4.2 Documenta tion -----------------------------------4.3 Master drawing ------------------------------- ---4.4 Printed-wiring assembly drawing -----------------4.s Production master -------------------------------
5.5.15.25.35.45.55.65.75.85.9
6.6.16.26.3
:::
OETAIL 90AR0 REQu IREMENTS -------------------------Conductive patter n ------------------------------Lands -------------------------------------------Hol es -------------------------------------------Eyelets and standoff terminal s ------------------Plated-through holes --------------------- -------Mater ial s ---------------------------------------Printed-wiring board dimensi ens -----------------Oetail board marking requiremen to ---------------Quality conformance testing circui try -----------
OETAIL PART MOUNTING REQUIRE MENTS -----------------Approved methods of attachment ------------------Electrical part mount ing ------------------------Con formal coating -------------------------------Support -----------------------------------------Oetai led assembly marking requiremen to ----------
APPENo Ix
Paragraph 10. SC OPE -------------------------------------------10. I Pr D05e ---------------------------------------
20. OESIGN CON SIOERATIOW S ---------------------------20.1 0esi3n process tolerances and all Owance -------20.2 Board dimension s ------------------------------211.3 Dimensional stabili ty -------------------------20.4 Dielectric constant and dissipation facto r----20.5 Surface preparation of large conductive areas --20.6 High voltage facto rs ---------------------------
T49LES
Table 1. Conductor spacing ---------------------------------11. Standard fabrication allowances for
plated-through hole dttachmcnt ------------------Ill. Standard fabrication allowances for surface
attach meat s ---------- --------------------- ------IV. Clad ldminlt e;-------------------- . . . . . . . . . . . . . . . .
v. Conformance test circui try ------------------------V1. CQmposite board design quiddnce -------------------
PAGE
11
2
4
555577
19131414
2323
23
;;23232323
9
11
,.,. ,.

.. . . . . . . ..-nlL->l U- Z/>L31 Lb2cember 198/.
FIGuREs
Figure 1.2.
3.4.
2:7.8.9.
10.11.12.13.14.15.16.17.
18.19.20.
Quality, conformance test circui try ----------------Block diagram depictfng typical printed wiring
drawing relation ships ---------------------------Use of grids in defining pattern requirement s-----Conductor thickness and width ---------------------Oiscrete leadless component land pattern ----------Chip carrier land patter n ------------------------ -Modified fan out pattern s ------------------- ------Heel mounting requirement s --------------- ---------TYP~cal flat pack l and ----------------------------Coined er flattened lead lands ---------------------Annular ring requirements (External )--------------Annular ring requirements ( Interna l )--------------Minimum annular ring dimensions (External )--------Ground plane lands (typic a l)----------------------Hole diaeter for flat lead -----------------------Dielectric layer thickness easurement ------------Location of test coupon based on number of boards
fabricated per panel --------------------------- .Flat lead terminate on -----------------------------Lead bend ---------------------------------------- -Perpendicular part mount ing -----------------------
PAGE
38
;;404041
44454646
iv

HIL-STD-275E31 December 1904
1. SCOPE
1.1 Purpose. This standard establishes desfgn requirements qoverninq rigid,single --rinted-wiri ng boards, double-sided printed -wirfng boards, multilayeredprinted-wiring boards, printed-wiring assemblies constructed from those boardsmentioned above, and design considerations for the ounttng of parts and assembliesthereon. The design criteria (such as electrical soacings) contained in thisstandard are predicated on the requirement that end item assemblies [circuit cardassembl ies, printed-wiring assemblies, hack planes, mother boards) shall beconformably coated (see 6.3.1). Con formal coating shall be in accordance withHIL-l -45059.
l.? Classification. Printed-wiring boards shall be of the types shown, asspecified [see 4.2):
Type 1 - Single-sided boardType 2 - Double-sided boardType 3 - 14ultilayer board

MIL. ST! I.275E31 December 198A
2. REFE!4ENCEII 00CIJ14ENTS
2.1 Government documents.
I 2 .1.1 ~fcations, stand.irds, and handbooks. !Jnless otherwise specfffed, thefollowing specl Tl cations, standards, and handbooks, of the is Sue listed in that issueof the Oeo,artment of Defense Index of SDecificatfons and Standards (n ODISS) SDecffiedin the solicitation, form a part of this standard to the extent specified herein.
SPECIFICATIONS
FEo ER4L
L-F-340
QQ.8-626
Qq-B-750
QQ-c-576
gQ. N.2909Q-S-571
MILITARY
NIL- O-851O
MI L-P-13949
MI L-C-14550MI L-P-28909MI L- G.45204HiL-i.46Ci53
MI L- P-5511O!IIL-P-E11728
STAN DAROS
MILITARY
OOO-5TD-1OOMI L- STO-130000- ST D-1686
Yilm, Sensitized, Wash-Off Process, Oiazotype, Moist andOrY pr0ce5s, Brown print, Roll and Sheet.9rass, Leaded and NOnleaded Rod, Shapes, Forgings and FlatProducts with Finished Edges i8ar, Flat Mire and Strip).Bronze, Phosphor Bar, Plate, koft, Sheet, Strip, Fl atwire,and Structural and Special Shaped Sections.Copper Flat Products with Slit, Slit and Edge-Rolled,Sheared, Sawed, or Nachined Edges. (Plate, 8ar, Sheet, andStrip).
!lickel Plating (Elect rodepositedl.Solder; Tln Alloy; Lead-Tin A11oY: and Lead A11oY.
Orawings, ,lndimensio~ed, ReDroducibl es, Photo qraohic andContact, Preparation of.Plastic Sheet, Laminatei, 4etal -Clad (For Printed Wirinql.General Specification for.Copper Plating (Electrofleoos itedl.Printed .Wi ring 4ssembli es.Gold plating, Elect redeposited.insulating iompouna, Eiectricai (For Coating PrintedCircuit Assemblies).Prfnted-li iring 9oarrts.Plating, Tin-Lead, EIectrodeposi ted.
Engineering Orawing Practices.Identification Marking of !J. S. Military Property.Electrostatic Discharge Control Program For Protection ofElectrical and Electronic Parts, Assemblies and fqufpment.
fCopfes of specifications, standards, drawings. and publications required bymanufacturers in connection with specific acquisition functions should be obtaine4from the contracting activity or as directed by the contracting of ficer. )
2.2 Other publications. The following docunents form a part of this standard tothe extent tndlcatert herein. The issues of the documents which are indicated as 9q0adopted shall be the issue listed in the current Don[Ss and the supplement thereto,if ao~licahle,
AMERICAY NAT ION4L $TANn ARnS INSTITUTE (ANSI)
AN SI. Y14.5 Oimensioninq and Tolerancing for Engineering Orawings.AN S1-Y14. I Orawing Sheet Size and Format

MI L. STD-275E31 Oecember 1984
[Application for copies should be addressed to the hmerican !lational StandardsInstitute, Inc. , 1430 Broadway, New york, My 10018. )
A3ER1C4N sOCIET7 FOR TESTING ANO MATERIALS (ASTq)
ASTM - E53 Standard Method for Che~ical Analysis of Copper(Electrolytic Determination of Copper).
[A DPli Catf On for COl)ie S should be addressed to the America. Society for Testing andMaterials, 1916 Race Street, hiladelohia. pA 19103. )
INsTITUTE OF ELECTRICAL AND ELECTRONICS ENGINEERS (IEEE)
lEEE-STO-200(ANSI Y3?.16) - Reference designations for CIectrlcal andElectronic Darts and Equipments.
(Application for coPies should be addressed to Institute of Electrical andElectronics Engineers Service Center, ATTN: publication $al es, ~~~ Yose La IIe,Piscataway. NJ 08854. )
INSTITUTE FOR Iv TERCflNNECTING ANO PACKAGING Electronic CIQCUITS (l PC)
IPC-T-50 Terms and Definitions.IPC-CF-15fT Copper Foil for Printed qi ring fiDPlicati Ofls.lPC-O.350 End Product Oescri Dtion in Numeric Form.IPC-S-815 General Requirements for Soldering Electronic
Interconnections.IPC-SM. B40 qualification and Performance of Permanent Polymer
Coating (Solder Mask) for Printed Boards.
(App

military standard - · pdf filemil -std. 275e 51 ikrew!wr [?/,4 superseding mil -std -275d 26...

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