ASTM B734-97(2018)
(Specification)Standard Specification for Electrodeposited Copper for Engineering Uses
Standard Specification for Electrodeposited Copper for Engineering Uses
ABSTRACT
This specification establishes the requirements for electrodeposited copper coatings used for engineering purposes including surface hardening, heat treatment stop-off, as an underplate for other engineering coatings, for electromagnetic interference shielding in electronic circuitry, and in certain joining operations. This specification does not cover electrodeposited copper used as a decorative finish, as an undercoat for other decorative finishes, or for electroforming. Coatings shall be classified according to thickness. Metal parts shall undergo pre- and post-coating treatment for reducing the risk of hydrogen embrittlement, and peening. Coatings shall be sampled, tested, and shall conform to specified requirements as to appearance, thickness, porosity, solderability, adhesion, embrittlement relief, and packaging.
SCOPE
1.1 This specification covers requirements for electrodeposited coatings of copper used for engineering purposes. Examples include surface hardening, heat treatment stop-off, as an underplate for other engineering coatings, for electromagnetic interferences (EMI) shielding in electronic circuitry, and in certain joining operations.
1.2 This specification is not intended for electrodeposited copper when used as a decorative finish, or as an undercoat for other decorative finishes.
1.3 This specification is not intended for electrodeposited copper when used for electroforming.
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
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Buy Standard
Standards Content (Sample)
This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: B734 −97 (Reapproved 2018)
Standard Specification for
Electrodeposited Copper for Engineering Uses
This standard is issued under the fixed designation B734; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope B568 Test Method for Measurement of Coating Thickness
by X-Ray Spectrometry
1.1 This specification covers requirements for electrodepos-
B571 Practice for Qualitative Adhesion Testing of Metallic
ited coatings of copper used for engineering purposes. Ex-
Coatings
amples include surface hardening, heat treatment stop-off, as
B588 Test Method for Measurement of Thickness of Trans-
an underplate for other engineering coatings, for electromag-
parent or Opaque Coatings by Double-Beam Interference
netic interferences (EMI) shielding in electronic circuitry, and
Microscope Technique (Withdrawn 2016)
in certain joining operations.
B602 Test Method for Attribute Sampling of Metallic and
1.2 This specification is not intended for electrodeposited
Inorganic Coatings
copper when used as a decorative finish, or as an undercoat for
B678 Test Method for Solderability of Metallic-Coated
other decorative finishes.
Products
B697 Guide for Selection of Sampling Plans for Inspection
1.3 This specification is not intended for electrodeposited
copper when used for electroforming. of Electrodeposited Metallic and Inorganic Coatings
B762 Test Method of Variables Sampling of Metallic and
1.4 This international standard was developed in accor-
Inorganic Coatings
dance with internationally recognized principles on standard-
B765 GuideforSelectionofPorosityandGrossDefectTests
ization established in the Decision on Principles for the
for Electrodeposits and Related Metallic Coatings
Development of International Standards, Guides and Recom-
B832 Guide for Electroforming with Nickel and Copper
mendations issued by the World Trade Organization Technical
B849 Specification for Pre-Treatments of Iron or Steel for
Barriers to Trade (TBT) Committee.
Reducing Risk of Hydrogen Embrittlement
2. Referenced Documents
B850 GuideforPost-CoatingTreatmentsofSteelforReduc-
ing the Risk of Hydrogen Embrittlement
2.1 ASTM Standards:
B851 Specification for Automated Controlled Shot Peening
B320 Practice for Preparation of Iron Castings for Electro-
of Metallic Articles Prior to Nickel, Autocatalytic Nickel,
plating
or Chromium Plating, or as Final Finish
B374 Terminology Relating to Electroplating
D3951 Practice for Commercial Packaging
B487 Test Method for Measurement of Metal and Oxide
F519 Test Method for Mechanical Hydrogen Embrittlement
Coating Thickness by Microscopical Examination of
Evaluation of Plating/Coating Processes and Service En-
Cross Section
vironments
B499 Test Method for Measurement of Coating Thicknesses
2.2 Military Standard:
by the Magnetic Method: Nonmagnetic Coatings on
MIL-R-81841 Rotary Flap Peening of Metal Parts
Magnetic Basis Metals
MIL-S-13165 Shot Peening of Metal Parts
B504 Test Method for Measurement of Thickness of Metal-
MIL-W-81840 Rotary Flap Peening Wheels
lic Coatings by the Coulometric Method
B507 Practice for Design of Articles to Be Electroplated on
3. Terminology
Racks
3.1 Definitions of Terms Specific to This Standard:
This specification is under the jurisdiction of ASTM Committee B08 on 3.1.1 significant surfaces—those surfaces normally visible
Metallic and Inorganic Coatings and is the direct responsibility of Subcommittee
(directlyorbyreflection)thatareessentialtotheappearanceor
B08.03 on Engineering Coatings.
serviceability of the article when assembled in a normal
Current edition approved June 1, 2018. Published June 2018. Originally
approved in 1984. Last previous edition approved in 2013 as B734 – 97 (2013).
DOI: 10.1520/B0734-97R18.
2 3
For referenced ASTM standards, visit the ASTM website, www.astm.org, or The last approved version of this historical standard is referenced on
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM www.astm.org.
Standards volume information, refer to the standard’s Document Summary page on AvailablefromStandardizationDocumentsOrderDesk,Bldg.4SectionD,700
the ASTM website. Robbins Ave., Philadelphia, PA 19111-5094. Attn: NPODS.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
B734 − 97 (2018)
position; or which can be the source of corrosion products that 5.4 If required by either party, the manufacturer of the parts
deface visible surfaces on the assembled article. When to be electroplated shall provide the electroplating facility with
necessary, the significant surface shall be indicated on the separate test specimens (see section 8.1).
drawing of the article, or by the provision of suitably marked
6. Coating Requirements
samples.
6.1 Appearance—The coating on the significant surfaces of
NOTE 1—When significant surfaces are involved on which the specified
the product shall be smooth and free of visual defects such as
thickness of coating cannot readily be controlled, such as threads, holes,
blisters, pits, roughness, cracks, flaking, burned deposits, and
deep recesses, and bases of angles, it will be necessary to apply thicker
uncoated areas. The boundaries of electroplating that cover
coatings on the more accessible surfaces, or to use special racking or both.
only a portion of the surface shall, after finishing as indicated
3.1.2 inspection lot—a collection of coated articles that; are
in the drawing, be free of beads, nodules, jagged edges and
of the same type; have been produced to the same specifica-
other detrimental irregularities. Imperfections and variations in
tions; have been coated by a single supplier at one time, or at
appearance in the coating that arise from surface conditions of
approximately the same time, under essentially identical con-
the basis metal (scratches, pores, roll marks, inclusions, etc.)
ditions; and are submitted for acceptance or rejection as a
and that persist in the finish despite the observance of good
group.
metal finishing practices shall not be cause for rejection.
3.2 Definitions—For definitions of the technical terms used
NOTE 3—Electroplated finishes generally perform better when the
in this specification see Terminology B374.
substrateoverwhichtheyareappliedissmoothandfreeofdeepscratches,
tornmetal,pores,inclusions,andotherdefects.Itisrecommendedthatthe
4. Classification
specifications covering the unfinished product provide limits for these
defects. A metal finisher can often remove defects through special
4.1 The electrodeposited copper is classified according to
treatments such as grinding, polishing, abrasive blasting, and special
thickness of the electrodeposit in the following table:
chemical treatments. However, these are not normal treatment steps.
When they are desired, they must be agreed upon between the buyer and
Class Minimum Thickness, µm
the producer.
25 25
20 20
6.2 Thickness—The thickness of the copper coating on the
12 12
significant surfaces shall conform to the requirements of the
x Thickness specified
specified class as defined in Section 4.
NOTE 2—For electroforming applications, that require much thicker
NOTE 4—Variation in the coating thickness from point-to-point on a
applications, see Guide B832.
coated article is an inherent characteristic of electroplating processes.
Therefore, the coating thickness will have to exceed the specified value at
some points on the significant surfaces to ensure that the thickness equals
5. Ordering Information
orexceedsthespecifiedvalueatallpoints.Asaresult,theaveragecoating
5.1 The buyer shall supply to the producer in the purchase
thicknessonanarticlewillusuallybegreaterthanthespecifiedvalue;how
muchgreaterislargelydeterminedbytheshapeofthearticle(seePractice
order or engineering drawings; marked samples or other
B507) and the characteristics of the electroplating process. Additionally,
governing documents the following information:
the average coating thickness on an article will vary from article to article
5.1.1 Title, ASTM designation number (Specification
within a production lot. Therefore, if all of the articles in a production lot
B734), and date of issue.
are to meet the thickness requirement, the average coatingthicknessofthe
5.1.2 Classification or thickness of electrodeposited copper production lot as a whole will be greater than the average necessary to
ensure that a single article meets the requirements.
(see 4.1),
NOTE 5—When electroplating threaded parts such as machine screws,
5.1.3 Significant surfaces if other than defined in 3.1.1,
care is required to avoid too much plate buildup on the crest of the thread.
5.1.4 Sampling plan (Section 7),
In such applications a maximum plate thickness allowable on the crests
may require that thicknesses in other areas be thinner.
5.1.5 Number of test specimens for destructive testing
(Section 8), and
6.3 Porosity—When specified, the coating shall be suffi-
5.1.6 Thickness, adhesion, solderability, porosity and num-
ciently free of pores to pass the porosity test specified in 8.4.
ber of pores acceptable, or hydrogen embrittlement tests and
6.4 Solderability—When specified, the coating shall meet
methods required (Section 8).
the requirements of Test Method B678.
5.2 Where required, dimensional tolerances allowed for the
6.5 Pretreatment of Iron and Steel for Reducing the Risk of
specified electroplated copper thickness shall be specified.
Hydrogen Embrittlement—Parts for critical applications that
are made of steels with ultimate tensile strengths of 1000 MPa,
5.3 Inadditiontotherequirementsof5.1andwhentheparts
hardness of 31 HRC or greater, that have been machined,
to be electroplated are supplied to the electroplater by the
ground, cold formed, or cold straightened subsequent to heat
buyer, the buyer shall also supply the following information as
treatment, shall require stress relief heat treatment when
required.
specified by the purchaser, the tensile strength to be supplied
5.3.1 Identity of the base material by alloy identification
by the purchaser. Specification B849 may be consulted for a
such as ASTM, AISI, or SAE numbers, or equivalent compo-
list of pretreatments that are used widely.
sition information,
5.3.2 Hardness of the parts, and
6.6 Post Coating Treatment of Iron and Steel for Reducing
5.3.3 Heat treatment for stress relief, whether it has been the Risk of Hydrogen Embrittlement—Parts for critical appli-
performed or is required. cationsthataremadeofsteelswithultimatetensilestrengthsof
B734 − 97 (2018)
1000 MPa, hardness of 31 HRC or greater, as well as surface 8. Test Methods
hardened parts, shall require post coating hydrogen embrittle-
8.1 The permission or the requirement to use special test
ment relief baking when specified by the purchaser, the tensile
specimens, the number to be used, the material from which
strength to be supplied by the purchaser. Specification B850
they are to be made, and their shape and size shall be stated by
may be consulted for a list of post treatments that are used
the purchaser.
widely.
NOTE 8—Test specimens often are used to represent the coated articles
6.7 Peening of Metal Parts—If peening is required before
in a test if the articles are of a size, shape, or material that is not suitable
for the test, or if it is preferred not to submit articles to a destructive test
electroplating to induce residual compressive stress to increase
because, for example, the articles are expensive or few in number. The
fatique strength and resistance to stress corrosion cracking of
specimen should duplicate the characteristics of the article that influence
the metal parts, refer to MIL-S-13165, MIL-R-81841, MIL-W-
the property being tested.
81840, and Specification B851.
8.1.1 Special test specimens used to represent articles in an
6.8 Supplementary Requirements:
adhesion, porosity, corrosion resistance, or appearance test
shall be made of the same material, in the same metallurgical
6.8.1 Packaging—If packaging requirements are to be met
under this specification, they shall be in accordance with condition, and have the same surface condition as the articles
they represent, and be placed in the production lot of and be
Practice D3951, or as specified in the contract or order.
processed along with the articles they represent.
(Warning—Some contemporary packaging materials may
emit fumes that are deleterious to the surface of the coating.) 8.1.2 Special test specimens used to represent articles in a
coatingthicknesstestmaybemadeofamaterialthatissuitable
7. Sampling for the test method even if the represented article is not of the
same material. For example, a low-carbon steel specimen may
7.1 The sampling plan used for the inspection of a quantity
represent a brass article when the magnetic thickness test is
of the coated articles shall be as agreed upon between the
used (Test Method B499). The thickness specimen need not be
purchaser and the seller.
carried through the complete process with the represented
article. If not, introduce it into the process at the point where
NOTE 6—Usually, when a collection of coated articles, the inspection
the coating is applied and carry it through all steps that have a
lot (7.2), is examined for compliance with the requirements placed on the
articles, a relatively small number of the articles, the sample, is selected at bearing on the coating thickness. In rack plating, rack the
randomandisinspected.Theinspectionlotthenisclassifiedascomplying
specimen in the same way with the same distance from and
or not complying with the requirements based on the results of the
orientation with the anodes and other items in the process as
inspection of the sample. The size of the sample and the criteria of
the article it represents.
compliance are determined by the application of statistics. The procedure
is known as sampling inspection. Three standards, Test Method B602,
NOTE 9—When special test specimens are used to represent coated
Guide B697, and Method B762 contain sampling plans that are designed
articles in a thickness test, the specimens will not necessarily have the
for the sampling inspection of coatings. Test Method B602 contains four
same thickness and thickness distribution as the articles unless the
sampling plans, three for use with tests that are non-destructive and one
specimens and the articl
...
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: B734 − 97 (Reapproved 2018)
Standard Specification for
Electrodeposited Copper for Engineering Uses
This standard is issued under the fixed designation B734; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope B568 Test Method for Measurement of Coating Thickness
by X-Ray Spectrometry
1.1 This specification covers requirements for electrodepos-
B571 Practice for Qualitative Adhesion Testing of Metallic
ited coatings of copper used for engineering purposes. Ex-
Coatings
amples include surface hardening, heat treatment stop-off, as
B588 Test Method for Measurement of Thickness of Trans-
an underplate for other engineering coatings, for electromag-
parent or Opaque Coatings by Double-Beam Interference
netic interferences (EMI) shielding in electronic circuitry, and
Microscope Technique (Withdrawn 2016)
in certain joining operations.
B602 Test Method for Attribute Sampling of Metallic and
1.2 This specification is not intended for electrodeposited
Inorganic Coatings
copper when used as a decorative finish, or as an undercoat for
B678 Test Method for Solderability of Metallic-Coated
other decorative finishes.
Products
1.3 This specification is not intended for electrodeposited B697 Guide for Selection of Sampling Plans for Inspection
of Electrodeposited Metallic and Inorganic Coatings
copper when used for electroforming.
B762 Test Method of Variables Sampling of Metallic and
1.4 This international standard was developed in accor-
Inorganic Coatings
dance with internationally recognized principles on standard-
B765 Guide for Selection of Porosity and Gross Defect Tests
ization established in the Decision on Principles for the
for Electrodeposits and Related Metallic Coatings
Development of International Standards, Guides and Recom-
B832 Guide for Electroforming with Nickel and Copper
mendations issued by the World Trade Organization Technical
B849 Specification for Pre-Treatments of Iron or Steel for
Barriers to Trade (TBT) Committee.
Reducing Risk of Hydrogen Embrittlement
2. Referenced Documents
B850 Guide for Post-Coating Treatments of Steel for Reduc-
ing the Risk of Hydrogen Embrittlement
2.1 ASTM Standards:
B851 Specification for Automated Controlled Shot Peening
B320 Practice for Preparation of Iron Castings for Electro-
of Metallic Articles Prior to Nickel, Autocatalytic Nickel,
plating
or Chromium Plating, or as Final Finish
B374 Terminology Relating to Electroplating
D3951 Practice for Commercial Packaging
B487 Test Method for Measurement of Metal and Oxide
F519 Test Method for Mechanical Hydrogen Embrittlement
Coating Thickness by Microscopical Examination of
Evaluation of Plating/Coating Processes and Service En-
Cross Section
vironments
B499 Test Method for Measurement of Coating Thicknesses
2.2 Military Standard:
by the Magnetic Method: Nonmagnetic Coatings on
MIL-R-81841 Rotary Flap Peening of Metal Parts
Magnetic Basis Metals
MIL-S-13165 Shot Peening of Metal Parts
B504 Test Method for Measurement of Thickness of Metal-
MIL-W-81840 Rotary Flap Peening Wheels
lic Coatings by the Coulometric Method
B507 Practice for Design of Articles to Be Electroplated on
3. Terminology
Racks
3.1 Definitions of Terms Specific to This Standard:
This specification is under the jurisdiction of ASTM Committee B08 on 3.1.1 significant surfaces—those surfaces normally visible
Metallic and Inorganic Coatings and is the direct responsibility of Subcommittee
(directly or by reflection) that are essential to the appearance or
B08.03 on Engineering Coatings.
serviceability of the article when assembled in a normal
Current edition approved June 1, 2018. Published June 2018. Originally
approved in 1984. Last previous edition approved in 2013 as B734 – 97 (2013).
DOI: 10.1520/B0734-97R18.
2 3
For referenced ASTM standards, visit the ASTM website, www.astm.org, or The last approved version of this historical standard is referenced on
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM www.astm.org.
Standards volume information, refer to the standard’s Document Summary page on Available from Standardization Documents Order Desk, Bldg. 4 Section D, 700
the ASTM website. Robbins Ave., Philadelphia, PA 19111-5094. Attn: NPODS.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
B734 − 97 (2018)
position; or which can be the source of corrosion products that 5.4 If required by either party, the manufacturer of the parts
deface visible surfaces on the assembled article. When to be electroplated shall provide the electroplating facility with
necessary, the significant surface shall be indicated on the separate test specimens (see section 8.1).
drawing of the article, or by the provision of suitably marked
6. Coating Requirements
samples.
6.1 Appearance—The coating on the significant surfaces of
NOTE 1—When significant surfaces are involved on which the specified
the product shall be smooth and free of visual defects such as
thickness of coating cannot readily be controlled, such as threads, holes,
blisters, pits, roughness, cracks, flaking, burned deposits, and
deep recesses, and bases of angles, it will be necessary to apply thicker
uncoated areas. The boundaries of electroplating that cover
coatings on the more accessible surfaces, or to use special racking or both.
only a portion of the surface shall, after finishing as indicated
3.1.2 inspection lot—a collection of coated articles that; are
in the drawing, be free of beads, nodules, jagged edges and
of the same type; have been produced to the same specifica-
other detrimental irregularities. Imperfections and variations in
tions; have been coated by a single supplier at one time, or at
appearance in the coating that arise from surface conditions of
approximately the same time, under essentially identical con-
the basis metal (scratches, pores, roll marks, inclusions, etc.)
ditions; and are submitted for acceptance or rejection as a
and that persist in the finish despite the observance of good
group.
metal finishing practices shall not be cause for rejection.
3.2 Definitions—For definitions of the technical terms used
NOTE 3—Electroplated finishes generally perform better when the
in this specification see Terminology B374.
substrate over which they are applied is smooth and free of deep scratches,
torn metal, pores, inclusions, and other defects. It is recommended that the
4. Classification
specifications covering the unfinished product provide limits for these
defects. A metal finisher can often remove defects through special
4.1 The electrodeposited copper is classified according to
treatments such as grinding, polishing, abrasive blasting, and special
thickness of the electrodeposit in the following table:
chemical treatments. However, these are not normal treatment steps.
When they are desired, they must be agreed upon between the buyer and
Class Minimum Thickness, µm
the producer.
25 25
20 20
6.2 Thickness—The thickness of the copper coating on the
12 12
significant surfaces shall conform to the requirements of the
5 5
x Thickness specified
specified class as defined in Section 4.
NOTE 2—For electroforming applications, that require much thicker
NOTE 4—Variation in the coating thickness from point-to-point on a
applications, see Guide B832.
coated article is an inherent characteristic of electroplating processes.
Therefore, the coating thickness will have to exceed the specified value at
some points on the significant surfaces to ensure that the thickness equals
5. Ordering Information
or exceeds the specified value at all points. As a result, the average coating
5.1 The buyer shall supply to the producer in the purchase
thickness on an article will usually be greater than the specified value; how
much greater is largely determined by the shape of the article (see Practice
order or engineering drawings; marked samples or other
B507) and the characteristics of the electroplating process. Additionally,
governing documents the following information:
the average coating thickness on an article will vary from article to article
5.1.1 Title, ASTM designation number (Specification
within a production lot. Therefore, if all of the articles in a production lot
B734), and date of issue.
are to meet the thickness requirement, the average coating thickness of the
production lot as a whole will be greater than the average necessary to
5.1.2 Classification or thickness of electrodeposited copper
ensure that a single article meets the requirements.
(see 4.1),
NOTE 5—When electroplating threaded parts such as machine screws,
5.1.3 Significant surfaces if other than defined in 3.1.1,
care is required to avoid too much plate buildup on the crest of the thread.
5.1.4 Sampling plan (Section 7),
In such applications a maximum plate thickness allowable on the crests
may require that thicknesses in other areas be thinner.
5.1.5 Number of test specimens for destructive testing
(Section 8), and
6.3 Porosity—When specified, the coating shall be suffi-
5.1.6 Thickness, adhesion, solderability, porosity and num-
ciently free of pores to pass the porosity test specified in 8.4.
ber of pores acceptable, or hydrogen embrittlement tests and
6.4 Solderability—When specified, the coating shall meet
methods required (Section 8).
the requirements of Test Method B678.
5.2 Where required, dimensional tolerances allowed for the
6.5 Pretreatment of Iron and Steel for Reducing the Risk of
specified electroplated copper thickness shall be specified.
Hydrogen Embrittlement—Parts for critical applications that
are made of steels with ultimate tensile strengths of 1000 MPa,
5.3 In addition to the requirements of 5.1 and when the parts
hardness of 31 HRC or greater, that have been machined,
to be electroplated are supplied to the electroplater by the
ground, cold formed, or cold straightened subsequent to heat
buyer, the buyer shall also supply the following information as
treatment, shall require stress relief heat treatment when
required.
specified by the purchaser, the tensile strength to be supplied
5.3.1 Identity of the base material by alloy identification
by the purchaser. Specification B849 may be consulted for a
such as ASTM, AISI, or SAE numbers, or equivalent compo-
list of pretreatments that are used widely.
sition information,
5.3.2 Hardness of the parts, and
6.6 Post Coating Treatment of Iron and Steel for Reducing
5.3.3 Heat treatment for stress relief, whether it has been the Risk of Hydrogen Embrittlement—Parts for critical appli-
performed or is required. cations that are made of steels with ultimate tensile strengths of
B734 − 97 (2018)
1000 MPa, hardness of 31 HRC or greater, as well as surface 8. Test Methods
hardened parts, shall require post coating hydrogen embrittle-
8.1 The permission or the requirement to use special test
ment relief baking when specified by the purchaser, the tensile
specimens, the number to be used, the material from which
strength to be supplied by the purchaser. Specification B850
they are to be made, and their shape and size shall be stated by
may be consulted for a list of post treatments that are used
the purchaser.
widely.
NOTE 8—Test specimens often are used to represent the coated articles
6.7 Peening of Metal Parts—If peening is required before
in a test if the articles are of a size, shape, or material that is not suitable
electroplating to induce residual compressive stress to increase for the test, or if it is preferred not to submit articles to a destructive test
because, for example, the articles are expensive or few in number. The
fatique strength and resistance to stress corrosion cracking of
specimen should duplicate the characteristics of the article that influence
the metal parts, refer to MIL-S-13165, MIL-R-81841, MIL-W-
the property being tested.
81840, and Specification B851.
8.1.1 Special test specimens used to represent articles in an
6.8 Supplementary Requirements:
adhesion, porosity, corrosion resistance, or appearance test
6.8.1 Packaging—If packaging requirements are to be met shall be made of the same material, in the same metallurgical
condition, and have the same surface condition as the articles
under this specification, they shall be in accordance with
they represent, and be placed in the production lot of and be
Practice D3951, or as specified in the contract or order.
processed along with the articles they represent.
(Warning—Some contemporary packaging materials may
emit fumes that are deleterious to the surface of the coating.) 8.1.2 Special test specimens used to represent articles in a
coating thickness test may be made of a material that is suitable
for the test method even if the represented article is not of the
7. Sampling
same material. For example, a low-carbon steel specimen may
7.1 The sampling plan used for the inspection of a quantity
represent a brass article when the magnetic thickness test is
of the coated articles shall be as agreed upon between the
used (Test Method B499). The thickness specimen need not be
purchaser and the seller.
carried through the complete process with the represented
article. If not, introduce it into the process at the point where
NOTE 6—Usually, when a collection of coated articles, the inspection
the coating is applied and carry it through all steps that have a
lot (7.2), is examined for compliance with the requirements placed on the
articles, a relatively small number of the articles, the sample, is selected at bearing on the coating thickness. In rack plating, rack the
random and is inspected. The inspection lot then is classified as complying
specimen in the same way with the same distance from and
or not complying with the requirements based on the results of the
orientation with the anodes and other items in the process as
inspection of the sample. The size of the sample and the criteria of
the article it represents.
compliance are determined by the application of statistics. The procedure
is known as sampling inspection. Three standards, Test Method B602,
NOTE 9—When special test specimens are used to represent coated
Guide B697, and Method B762 contain sampling plans that are designed
articles in a thickness test, the specimens will not necessarily have the
for the sampling inspection of coatings. Test Method B602 contains four
same thickness and thickness distribution as the articles unless the
sampling plans, three for use with tests that are non-
...
This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: B734 − 97 (Reapproved 2013) B734 − 97 (Reapproved 2018)
Standard Specification for
Electrodeposited Copper for Engineering Uses
This standard is issued under the fixed designation B734; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 This specification covers requirements for electrodeposited coatings of copper used for engineering purposes. Examples
include surface hardening, heat treatment stop-off, as an underplate for other engineering coatings, for electromagnetic
interferences (EMI) shielding in electronic circuitry, and in certain joining operations.
1.2 This specification is not intended for electrodeposited copper when used as a decorative finish, or as an undercoat for other
decorative finishes.
1.3 This specification is not intended for electrodeposited copper when used for electroforming.
1.4 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2.1 ASTM Standards:
B320 Practice for Preparation of Iron Castings for Electroplating
B374 Terminology Relating to Electroplating
B487 Test Method for Measurement of Metal and Oxide Coating Thickness by Microscopical Examination of Cross Section
B499 Test Method for Measurement of Coating Thicknesses by the Magnetic Method: Nonmagnetic Coatings on Magnetic Basis
Metals
B504 Test Method for Measurement of Thickness of Metallic Coatings by the Coulometric Method
B507 Practice for Design of Articles to Be Electroplated on Racks
B568 Test Method for Measurement of Coating Thickness by X-Ray Spectrometry
B571 Practice for Qualitative Adhesion Testing of Metallic Coatings
B588 Test Method for Measurement of Thickness of Transparent or Opaque Coatings by Double-Beam Interference Microscope
Technique (Withdrawn 2016)
B602 Test Method for Attribute Sampling of Metallic and Inorganic Coatings
B678 Test Method for Solderability of Metallic-Coated Products
B697 Guide for Selection of Sampling Plans for Inspection of Electrodeposited Metallic and Inorganic Coatings
B762 Test Method of Variables Sampling of Metallic and Inorganic Coatings
B765 Guide for Selection of Porosity and Gross Defect Tests for Electrodeposits and Related Metallic Coatings
B832 Guide for Electroforming with Nickel and Copper
B849 Specification for Pre-Treatments of Iron or Steel for Reducing Risk of Hydrogen Embrittlement
B850 Guide for Post-Coating Treatments of Steel for Reducing the Risk of Hydrogen Embrittlement
B851 Specification for Automated Controlled Shot Peening of Metallic Articles Prior to Nickel, Autocatalytic Nickel, or
Chromium Plating, or as Final Finish
D3951 Practice for Commercial Packaging
F519 Test Method for Mechanical Hydrogen Embrittlement Evaluation of Plating/Coating Processes and Service Environments
This specification is under the jurisdiction of ASTM Committee B08 on Metallic and Inorganic Coatings and is the direct responsibility of Subcommittee B08.03 on
Engineering Coatings.
Current edition approved Dec. 1, 2013June 1, 2018. Published December 2013June 2018. Originally approved in 1984. Last previous edition approved in 20082013 as
B734 – 97 (2008).(2013). DOI: 10.1520/B0734-97R13.10.1520/B0734-97R18.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
The last approved version of this historical standard is referenced on www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
B734 − 97 (2018)
2.2 Military Standard:
MIL-R-81841 Rotary Flap Peening of Metal Parts
MIL-S-13165 Shot Peening of Metal Parts
MIL-W-81840 Rotary Flap Peening Wheels
3. Terminology
3.1 Definitions of Terms Specific to This Standard:
3.1.1 significant surfaces—those surfaces normally visible (directly or by reflection) that are essential to the appearance or
serviceability of the article when assembled in a normal position; or which can be the source of corrosion products that deface
visible surfaces on the assembled article. When necessary, the significant surface shall be indicated on the drawing of the article,
or by the provision of suitably marked samples.
NOTE 1—When significant surfaces are involved on which the specified thickness of coating cannot readily be controlled, such as threads, holes, deep
recesses, and bases of angles, it will be necessary to apply thicker coatings on the more accessible surfaces, or to use special racking or both.
3.1.2 inspection lot—a collection of coated articles that; are of the same type; have been produced to the same specifications;
have been coated by a single supplier at one time, or at approximately the same time, under essentially identical conditions; and
are submitted for acceptance or rejection as a group.
3.2 Definitions—For definitions of the technical terms used in this specification see Terminology B374.
4. Classification
4.1 The electrodeposited copper is classified according to thickness of the electrodeposit in the following table:
Class Minimum Thickness, μm
25 25
20 20
12 12
5 5
x Thickness specified
NOTE 2—For electroforming applications, that require much thicker applications, see Guide B832.
5. Ordering Information
5.1 The buyer shall supply to the producer in the purchase order or engineering drawings; marked samples or other governing
documents the following information:
5.1.1 Title, ASTM designation number (Specification B734), and date of issue.
5.1.2 Classification or thickness of electrodeposited copper (see 4.1),
5.1.3 Significant surfaces if other than defined in 3.1.1,
5.1.4 Sampling plan (Section 7),
5.1.5 Number of test specimens for destructive testing (Section 8), and
5.1.6 Thickness, adhesion, solderability, porosity and number of pores acceptable, or hydrogen embrittlement tests and methods
required (Section 8).
5.2 Where required, dimensional tolerances allowed for the specified electroplated copper thickness shall be specified.
5.3 In addition to the requirements of 5.1 and when the parts to be electroplated are supplied to the electroplater by the buyer,
the buyer shall also supply the following information as required.
5.3.1 Identity of the base material by alloy identification such as ASTM, AISI, or SAE numbers, or equivalent composition
information,
5.3.2 Hardness of the parts, and
5.3.3 Heat treatment for stress relief, whether it has been performed or is required.
5.4 If required by either party, the manufacturer of the parts to be electroplated shall provide the electroplating facility with
separate test specimens (see section 8.1).
6. Coating Requirements
6.1 Appearance—The coating on the significant surfaces of the product shall be smooth and free of visual defects such as
blisters, pits, roughness, cracks, flaking, burned deposits, and uncoated areas. The boundaries of electroplating that cover only a
portion of the surface shall, after finishing as indicated in the drawing, be free of beads, nodules, jagged edges and other detrimental
irregularities. Imperfections and variations in appearance in the coating that arise from surface conditions of the basis metal
(scratches, pores, roll marks, inclusions, etc.) and that persist in the finish despite the observance of good metal finishing practices
shall not be cause for rejection.
Available from Standardization Documents Order Desk, Bldg. 4 Section D, 700 Robbins Ave., Philadelphia, PA 19111-5094. Attn: NPODS.
B734 − 97 (2018)
NOTE 3—Electroplated finishes generally perform better when the substrate over which they are applied is smooth and free of deep scratches, torn
metal, pores, inclusions, and other defects. It is recommended that the specifications covering the unfinished product provide limits for these defects. A
metal finisher can often remove defects through special treatments such as grinding, polishing, abrasive blasting, and special chemical treatments.
However, these are not normal treatment steps. When they are desired, they must be agreed upon between the buyer and the producer.
6.2 Thickness—The thickness of the copper coating on the significant surfaces shall conform to the requirements of the specified
class as defined in Section 4.
NOTE 4—Variation in the coating thickness from point-to-point on a coated article is an inherent characteristic of electroplating processes. Therefore,
the coating thickness will have to exceed the specified value at some points on the significant surfaces to ensure that the thickness equals or exceeds the
specified value at all points. As a result, the average coating thickness on an article will usually be greater than the specified value; how much greater
is largely determined by the shape of the article (see Practice B507) and the characteristics of the electroplating process. Additionally, the average coating
thickness on an article will vary from article to article within a production lot. Therefore, if all of the articles in a production lot are to meet the thickness
requirement, the average coating thickness of the production lot as a whole will be greater than the average necessary to ensure that a single article meets
the requirements.
NOTE 5—When electroplating threaded parts such as machine screws, care is required to avoid too much plate buildup on the crest of the thread. In
such applications a maximum plate thickness allowable on the crests may require that thicknesses in other areas be thinner.
6.3 Porosity—When specified, the coating shall be sufficiently free of pores to pass the porosity test specified in 8.4.
6.4 Solderability—When specified, the coating shall meet the requirements of Test Method B678.
6.5 Pretreatment of Iron and Steel for Reducing the Risk of Hydrogen Embrittlement—Parts for critical applications that are
made of steels with ultimate tensile strengths of 1000 MPa, hardness of 31 HRC or greater, that have been machined, ground, cold
formed, or cold straightened subsequent to heat treatment, shall require stress relief heat treatment when specified by the purchaser,
the tensile strength to be supplied by the purchaser. Specification B849 may be consulted for a list of pretreatments that are used
widely.
6.6 Post Coating Treatment of Iron and Steel for Reducing the Risk of Hydrogen Embrittlement—Parts for critical applications
that are made of steels with ultimate tensile strengths of 1000 MPa, hardness of 31 HRC or greater, as well as surface hardened
parts, shall require post coating hydrogen embrittlement relief baking when specified by the purchaser, the tensile strength to be
supplied by the purchaser. Specification B850 may be consulted for a list of post treatments that are used widely.
6.7 Peening of Metal Parts—If peening is required before electroplating to induce residual compressive stress to increase
fatique strength and resistance to stress corrosion cracking of the metal parts, refer to MIL-S-13165, MIL-R-81841, MIL-W-81840,
and Specification B851.
6.8 Supplementary Requirements:
6.8.1 Packaging—If packaging requirements are to be met under this specification, they shall be in accordance with Practice
D3951, or as specified in the contract or order. (Warning—Some contemporary packaging materials may emit fumes that are
deleterious to the surface of the coating.)
7. Sampling
7.1 The sampling plan used for the inspection of a quantity of the coated articles shall be as agreed upon between the purchaser
and the seller.
NOTE 6—Usually, when a collection of coated articles, the inspection lot (7.2), is examined for compliance with the requirements placed on the articles,
a relatively small number of the articles, the sample, is selected at random and is inspected. The inspection lot then is classified as complying or not
complying with the requirements based on the results of the inspection of the sample. The size of the sample and the criteria of compliance are determined
by the application of statistics. The procedure is known as sampling inspection. Three standards, Test Method B602, Guide B697, and Method B762
contain sampling plans that are designed for the sampling inspection of coatings. Test Method B602 contains four sampling plans, three for use with tests
that are non-destructive and one when they are destructive. The buyer and seller may agree on the plan or plans to be used. If they do not, Test Method
B602 identifies the plan to be used. Guide B697 provides a large number of plans and also gives guidance in the selection of a plan. When Guide B697
is specified, the buyer and seller need to agree on the plan to be used. Methods B762 can be used only for coating requirements that have numerical limit,
such as coating thickness. The test must yield a numerical value and certain statistical requirements must be met. Methods B762 contains several plans
and also gives instructions for calculating plans to meet special needs. The buyer and the seller may agree on the plan or plans to be used. If they do
not, Methods B762 identifies the plan to be used.
NOTE 7—When both destructive and non-destructive tests exist for the measurement of a characteristic, the purchaser needs to state which is to be used
so that the proper sampling plan is selected. A test may destroy the coating but in a non-critical area; or, although it may destroy the coating, a tested
part can be reclaimed by stripping and recoating. The purchaser needs to state whether the test is to be considered destructive or non-destructive.
7.2 An inspection lot shall be defined as a collection of coated articles that are of the same kind, that have been produced to
the same specifications, that have been coated by a single supplier at one time, or at approximately the same time under essentially
identical conditions, and that are submitted for acceptance or rejection as a group.
7.3 If special test specimens are used to represent the coated articles in a test, the number use
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