1、Designation: B904 00 (Reapproved 2009)Standard Specification forAutocatalytic Nickel over Autocatalytic Copper forElectromagnetic Interference Shielding1This standard is issued under the fixed designation B904; the number immediately following the designation indicates the year oforiginal adoption o
2、r, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. ScopeThis specification presents the requirements for multilayercoatings of autocatalyt
3、ic nickel-phosphorus over autocatalyticcopper on metallic and polymeric substrates. The coatingsystem is intended to provide electromagnetic interference(EMI) protection properties or electrostatic discharge (ESD)protection to parts fabricated from either polymeric or metallicmaterials.2. Referenced
4、 Documents2.1 ASTM Standards:2A919 Terminology Relating to Heat Treatment of Metals3B183 Practice for Preparation of Low-Carbon Steel forElectroplatingB242 Guide for Preparation of High-Carbon Steel for Elec-troplatingB252 Guide for Preparation of Zinc Alloy Die Castings forElectroplating and Conver
5、sion CoatingsB253 Guide for Preparation of Aluminum Alloys for Elec-troplatingB320 Practice for Preparation of Iron Castings for Electro-platingB322 Guide for Cleaning Metals Prior to ElectroplatingB374 Terminology Relating to ElectroplatingB504 Test Method for Measurement of Thickness of Me-tallic
6、Coatings by the Coulometric MethodB532 Specification for Appearance of Electroplated PlasticSurfacesB533 Test Method for Peel Strength of Metal ElectroplatedPlasticsB553 Test Method for Thermal Cycling of ElectroplatedPlasticsB554 Practice for Measurement of Thickness of MetallicCoatings on Nonmetal
7、lic Substrates3B567 Test Method for Measurement of Coating Thicknessby the Beta Backscatter MethodB568 Test Method for Measurement of Coating Thicknessby X-Ray SpectrometryB602 Test Method for Attribute Sampling of Metallic andInorganic CoatingsB697 Guide for Selection of Sampling Plans for Inspecti
8、onof Electrodeposited Metallic and Inorganic CoatingsB727 Practice for Preparation of Plastics Materials forElectroplatingB733 Specification for Autocatalytic (Electroless) Nickel-Phosphorus Coatings on MetalD3330/D3330M Test Method for Peel Adhesion ofPressure-Sensitive TapeD3359 Test Methods for M
9、easuring Adhesion by Tape TestD4935 Test Method for Measuring the ElectromagneticShielding Effectiveness of Planar Materials42.2 Military Standard:MIL-STD-461 Electromagnetic Emission and Susceptibil-ity Requirements for the Control of ElectromagneticInterference53. Terminology3.1 DefinitionsMany of
10、 the terms used in this specifica-tion can be found in Terminologies A919 or B374.3.2 Definitions of Terms Specific to This Standard:3.2.1 significant surfaces, nthese surfaces are classified asprimary, secondary, nonsignificant, and coating-free surfaces.3.2.1.1 coating-free areas, adjareas specifi
11、ed on partdrawings or suitably marked samples.3.2.1.2 nonsignificant surfaces, adjall holes, recesses, andother areas where a controlled deposit cannot be obtainedunder normal coating conditions and that cannot be touchedwith a 20-mm diameter ball shall be considered nonsignificantsurfaces unless ot
12、herwise specified on part drawings or suitablymarked samples.1This specification is under the jurisdiction of ASTM Committee B08 onMetallic and Inorganic Coatings and is the direct responsibility of SubcommitteeB08.08.01 on Engineering Coatings.Current edition approved Sept. 1, 2009. Published Janua
13、ry 2010. Originallyapproved in 2000. Last previous edition approved in 2004 as B904 00(2004). DOI:10.1520/B0904-00R09.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer t
14、o the standards Document Summary page onthe ASTM website.3Withdrawn.4Withdrawn. The last approved version of this historical standard is referencedon www.astm.org.5Available from Standardization Documents Order Desk, Bldg. 4 Section D, 700Robbins Ave. Philadelphia, PA 191115094, Attn: NPODS.1Copyrig
15、ht ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.2.1.3 primary significant surface, adjall mating sur-faces and those other surfaces specified on part drawings orsuitably marked samples.3.2.1.4 secondary significant surfaces, adjall surface
16、s,other than primary significant surfaces, that can be touchedwith a 20-mm diameter ball shall be considered secondarysignificant surfaces unless otherwise specified on part drawingsor suitably marked samples.4. Classification4.1 This classification system provides for the following:4.1.1 Types of c
17、oating based on thickness and testingrequirements, and4.1.2 Grades of coating based on alloy composition.4.2 Coating Type:4.2.1 The coating type indicates the type of application andtests to be used in determining the acceptance of the coating.4.2.2 Coating Type Definitions:4.2.2.1 Type 1Coatings in
18、tended to shield devices forFCC/VDE Class B service.4.2.2.2 Type 2Coatings intended to shield devices forFCC/VDE Class B service in harsh environments.4.2.2.3 Type 3Coatings intended to shield devices forMIL-STD-461 requirements.4.2.2.4 Type 4Coatings intended to shield devices forFCC/VDE Class A re
19、quirements.4.2.3 The description of Types 1, 2, 3, and 4 is summarizedin Table 1.4.3 Coating Grade:4.3.1 The coating grade is based upon phosphorus content.NOTE 1The coating grade indicates the relative contact impedanceand the relative corrosion resistance of the nickel-phosphorus coating andtests
20、to be used in determining the acceptance of the coating4.3.2 Coating Grade Definitions:4.3.3 Grade 1 coatings have a phosphorus content between3 and 5 %.NOTE 2Low phosphorus coatings exhibit low electrical contact im-pedance. High phosphorus contents exhibit somewhat higher contactimpedance, however
21、, the coating is more corrosion resistant.4.3.4 Grade 2 coatings have a phosphorus content between6 and 11 %.NOTE 3The adhesion and resistance to blistering are improved onsome polymeric substrates by an initial flash deposit of autocatalyticnickel.5. Ordering Information5.1 To avoid misunderstandin
22、g between contractual parties,purchase orders or contracts for autocatalytic nickel overautocatalytic copper coatings under this specification shouldinclude the designation, issue date, and the following informa-tion:5.1.1 Type of substrate.5.1.1.1 Metallic substrates should state the composition an
23、dmetallurgical condition. Assemblies of dissimilar materialsshould be identified.5.1.1.2 Polymeric substrates should state the polymer typeand should be of a plating grade.5.1.2 Classification of the deposit by type and grade.5.1.3 Primary significant surfaces and coating-free surfacesmust be indica
24、ted on drawings.5.1.4 Any special requirements.5.1.5 Test methods for coating adhesion, thickness, porosity.5.1.6 Sampling program.6. Surface Preparation6.1 Surface ContaminationSurfaces of polymeric partsmust be free of all mold release agents, dirt, oil, grease, andcontamination detrimental to the
25、 final finish. Surfaces ofmetallic parts must be free of all scale, oxidation, and contami-nation detrimental to the final finish. A clean surface isessential to the adhesion and electrical conductivity require-ments of the subsequent coated part.6.2 Cleaning, Conditioning, and ActivatingAny adequat
26、emethod of cleaning, conditioning, and activating is acceptableprovided the coated parts meet the inspection requirements andare free of distortion. Examples of adequate methods ofcleaning can be found in 10.2.6.2.1 Base Material SuitabilityThe parts to be coatedshall be inspected by the coater prio
27、r to any processing todetermine their suitability for coating. Unsuitable parts shall bereturned to the fabricator or molder.6.3 Mechanical RougheningMechanical roughening ofpolymer surfaces, to promote adhesion, may only be used whenspecified on the part drawing.7. In-Process Storage and Handling7.
28、1 Following cleaning, conditioning, and activating, allparts shall be immediately coated with copper and thennickel-phosphorus to the thickness specified in Table 1. Theparts processing cycle shall be a continuous operation withoutany interruption.7.2 HandlingThe parts shall be suitably racked so as
29、 toprevent gas entrapment and to avoid physical handling of theprimary significant surfaces.7.3 DryingFollowing coating, the parts may be dried withwarm air currents. Drying temperature shall not exceed theheat distortion temperature of the substrate. Wetting agentsmay be used to enhance water shedd
30、ing provided they do notinterfere with subsequent paint adhesion.TABLE 1 Autocatalytic Nickel-Phosphorus Over AutocatalyticCopper Coating Descriptions SummaryType Thickness ShieldingEffectiveness(Typical) inaccordance withTest MethodD4935ApplicationAutocatalyticCopperAutocatalyticNickel-Phosphorus1
31、1 m min 0.25 m min 80-100 dB FCC/VDEClass B2 1 m min 1.5 m min 80-100 dB HarshEnvironment3 2.5 m min 0.25 m min 90-110 dB MIL-STD-461B4 Optional/Notrequired1.0 m min 50-70 dB FCC/VDEClass AB904 00 (2009)27.4 StorageFollowing drying, all parts shall be stored in aclean dry area, protected from corros
32、ive fumes and humidityprior to packaging and shipment.8. Inspection8.1 Process QualificationAll nickel-phosphorus overcopper coatings shall be produced from processes qualified inaccordance with the requirements in Section 9.8.2 Nickel-Phosphorus Over Copper CoatingThe nickel-phosphorus coating shal
33、l meet the requirements of Specifica-tion B733.8.2.1 AppearanceThe nickel-phosphorus over coppercoating shall be smooth, semi-bright, adherent, and free fromdefects that will impair the corrosion resistance, electricalconductivity or electromagnetic shielding effectiveness prop-erties of the coating
34、, see Specification B532 for polymericparts and Specification B733 for metallic parts.8.2.2 Blisters and Unplated Areas8.2.2.1 BlistersThe parts shall be examined visually for10 to 15 s or as necessary to adequately examine the entireplated surface at a distance of 600 to 900 mm (arms length) forevi
35、dence of blisters. Visually means 20/20 vision or correctedto 20/20. Parts exhibiting blisters shall be rejected.8.2.2.2 Unplated AreasVoids, skips, and other unplatedareas, visible to the unaided eye, exposing the substrate shall belimited to the sizes and numbers shown in Table 2. Voids andskips e
36、xposing copper are not permitted.8.2.3 ThicknessThe thickness test shall be performed onthe primary and secondary significant surfaces of the finishedpart. Thickness shall be as specified in Table 1. For partsacceptance the combined thickness of deposit and tolerancespecified in Table 1 may be used,
37、 provided representative partsalso meet the electrical conductivity requirements specified in8.2.5. The thickness of deposit on nonsignificant surfaces shallbe that which results from control on the primary and second-ary significant surfaces, provided plating coverage occurs,unless otherwise specif
38、ied on the part drawing.8.2.3.1 Thickness Test MethodsThe following test meth-ods are suitable for measuring local thickness of nickel-phosphorus and copper coating, see Practice B554. See 8.2.3.2for restrictions.Coulometric MethodSee Test Method B504X-Ray MethodSee Test Method B568Beta Backscatter
39、MethodSee Test Method B567(1) Coulometric MethodThis semi-destructive method issuitable for the measurement of individual layers in the rangeof 0.25 to 100 m.(2) X-Ray MethodThis nondestructive method is suitablefor the measurement of individual layers in the range of 0.25 to65 m and shall be the re
40、feree method.(3) Beta Backscatter MethodThis nondestructive methodis suitable for measuring total coating thickness between 0.1and 100 m.8.2.3.2 RestrictionElectronic thickness testers utilizingthe Eddy-current principle are not suitable for this specificationand shall not be used.8.2.4 AdhesionThe
41、coatings shall not peel or separatefrom the base material when subjected to the tape test (see9.4.1).8.2.5 Electrical ContinuityThe coating shall form a con-tinuous electrical path across the significant and nonsignificantsurfaces.8.2.5.1 Electrical CriteriaThe DC resistance of the coat-ing system,
42、between all points of the primary significantsurfaces shall not exceed 0.1 V unless otherwise specified onpart drawings. The measurement shall be made with anohmmeter, having a sensitivity of at least 20 000 V/V, and ameasuring voltage of 9 6 3 V DC and a 2 A load.8.2.5.2 Electrical Measurement Proc
43、edureThe DC resis-tance of the coating system, shall be measured on a test sampleprepared by assembling two coated parts together, clampingthem with 2 M4, class 4.8 threaded fasteners assembled withtwo flat washers and a mating nut torqued to 1.52.0 NM. Themeasuring probes shall each be pressed firm
44、ly into the oppos-ing faces of the assembly so as to make intimate contact withthe coating. Alternatively, when it is not practical to assembletwo parts together for this test, a single part may be used. Inthat event, press one probe firmly into the surface of the part sothat it is in intimate conta
45、ct with the coating. The second probeshall be held in contact with the part surface, in a position andwith a pressure approximating that of writing with a pencil.This probe shall have a radius of 1 mm minimum. The probesshall be held at least 25 and no more than 200 mm apart.8.3 SamplingA suitable s
46、ampling plan may be selectedfrom those in Test Method B602. Guidance in selecting asuitable sampling plan will be found in Guide B697.9. Requirements for Process Qualification9.1 Process SelectionCommercial processes are availablethat meet the requirements of this specification.9.2 Coating Compositi
47、onThe composition of the nickel-phosphorus coating shall be 3 to 11 % phosphorus and theremainder nickel. The composition of the copper coating shallbe 99 % copper minimum.9.3 Electrical IntegrityParts or coupons shall be subjectto 20 cycles of the cyclic temperature-humidity test and then tothe req
48、uirements of 8.2.5.1 and 8.2.5.2.9.4 AdhesionThe coatings shall not peel or separate fromthe base material when subjected to the following tests.9.4.1 Tape Test:9.4.1.1 Apply a piece of pressure sensitive filament tape,approximately 25 mm wide and 75 mm long, onto the coatedsurface, pressing it firm
49、ly into place. Remove the tape, within5 minutes, with a continuous, smooth and rapid pull at an angleof approximately 90.9.4.2 The filament tape shall be 25 6 1 mm wide semitrans-parent pressure-sensitive tape with an adhesion strength of44.66 2.8 g/mm width when tested in accordance with TestMethods D3330/D3330M. The adhesion shall not change morethan 6 6.5 % of its mean value within 12 months.9.4.2.1 Pass/Fail CriteriaRemoval of any metal coatingshall constitute test failure.TABLE 2 Allowable Unplated AreasArea Size/Void, ma
