GB/T 39807-2021.Process specifications of Pb-free plating tin and tin alloys.
1 Scope
GB/T 39807 specifies the process requirements, product quality requirements and sampling for electroplating pure tin and tin-copper alloys.
GB/T 39807 is applicable to solderable electroplating pure tin and electroplating tin-copper alloys in the electronics industry.
GB/T 39807 is not applicable to decorative electroplating of tin and tin alloys.
2 Normative references
The following documents are essential for the application of this document. For all dated references, only the dated version applies to this document. For all undated references, the latest version (including all amendments) applies to this document.
GB/T 2423.28 Environmental testing for electric and electronic products Part 2: Test methods Test T: Soldering
GB/T 3138 Metallic and other inorganic coatings. Terminology for surface treatment
GB/T 9789 Metallic and other inorganic coatings - Sulfur dioxide corrosion test under normal condensation conditions
GB/T 10125 Corrosion test in artificial atmosphere - Salt spray test
GB/T 12609 Sampling procedure for counting inspection of electrodeposited metallic coatings and related finishes
GB/T 12334 Definitions and general rules for thickness measurement of metallic and other non-organic coatings
GB/T 12599-2002 Technical specifications and test methods for tin electroplated coatings of metallic coatings
3 Terms and definitions The terms and definitions
defined in GB/T 3138 and GB/T 12334 and the following terms and definitions apply to this document.
3.1
Pb-free plating tin and tin alloys
Electroplated tin and tin alloy coatings that do not contain lead.
3.2
Electroplated pure tin
Electroplated tin coatings with a carbon content of less than 0.05% and a tin content of more than 99.95%.
3.3
Electroplated tin-copper
Tin-copper alloy coatings with a copper content of 2% to 4%.
This standard specifies the process requirements, product quality requirements and sampling for electroplating pure tin and tin-copper alloys. This standard applies to solderable electroplated pure tin and electroplated tin-copper alloys in the electronics industry. This standard does not apply to decorative tin and tin alloy electroplating.

ICIS25.220.40
A 29
National Standard of the People's Republic of China
GB/T39807—2021
Process specifications of Pb-free electroplating tin and tin alloys
Process specirications of Pb-free plating tin and tin alloys2021-03-09Published
State Administration for Market RegulationbzxZ.net
National Administration of Standardization
Published
2021-10-01Implementation
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Foreword
Scope
Normative references
Terms and definitions
Process requirements
Process flow
Niu Production control
Replacement test sample
Equipment requirements
Product quality requirements
Substrate requirements
Copper and tin content of coating
Appearance of coating
Coating thickness
Bonding strength
Solderability
Porosity
Anti-discoloration performance
Anti-tin whisker performance
Sampling
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GB/T 39807—2021
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This standard was drafted in accordance with the rules given in GB/T1.12009. This standard was proposed by the China Machinery Industry Federation. This standard is under the jurisdiction of the Shandong Tongjin Bureau and the Technical Committee for Standardization of Non-metallic Coverings (SAC/TC.57). GB/T 39807—2021
Drafting units of this standard: Wuhan Institute of Material Protection Co., Ltd., Guangdong Dazhi Environmental Protection Technology Co., Ltd., Hefei Dongzhirui Mechanical Technology Co., Ltd., Zhaoqing College, Foshan Kegao Technology Co., Ltd., Wuhan Aobang Surface Technology Co., Ltd., Wuhan Caibao Surface New Materials Co., Ltd.
Main drafters of this standard: Mao Zuguo, Cai Zhihua, Yunhu, Yi Juan, Weidong, Huang Xinglin, Zhong Ping, Gan Sheyuan, Yuan Xing, Xia Jingzhong Niu Yanli, Zhi, Pin Mingwei, Gong Zijian
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1 Scope
Process specification for lead-free electroplating tin and tin-copper alloys
This standard specifies the process requirements, product quality requirements and sampling for electroplating pure tin and tin-copper alloys. This standard applies to solderable electroplating pure tin and electroplating tin-copper alloys in the electronics industry. This standard does not apply to decorative tin and tin alloy electroplating. Normative references GB/T39807—2021 The following documents are essential for the application of this document. For all dated references, only the dated version applies to this document. For all undated references, the latest version (including all amendments) applies to this document. GB/T 2423.28 GH/T 3138 GB/T 9789 GB/T10125 GB/T 12600
GB/T12331
Environmental testing for electrical products Part 2 Test methods Test T: Soldering Terminology for surface treatment of metals and other inorganic coatings Sulfur dioxide corrosion test under normal condensation conditions Corrosion test in artificial atmosphere Salt spray test
Electrodeposited metal coatings and finishing
Sampling procedure for inspection by counting
Definitions and general rules for thickness measurement of metals and other non-organic coatings GB/T12599-2002 Metallic coatings
Technical specifications and test methods for tin electroplating
3 Terms and definitions
The terms and definitions defined in GB/T3138 and GB/T12334 and the following terms and definitions are applicable to this document. 3.1
Ph-freeplatingtin and tinalloysPh-freeplatingtin and tinalloysPh-freeplatingtin and tin alloy coatings without lead
electroplatingpuretin
electroplatingtin-copper
electroplatingtin-copper alloy coatings with a copper content of 2% to 4%. Process requirements
4.1 Process flow
4.1.1 Pre-plating treatment
Pre-plating treatment adopts chemical degreasing, cathode electrolytic degreasing, anodic electrolytic degreasing and activation multi-pass combination 1. Technology 1
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GB/T39807—2021
2 Electroplating bottom coating (selective)
4.1.2
When any of the following reasons exists, some substrate surfaces may require a bottom coating: prevent diffusion (should be in accordance with GB/T125992002 C.2.2 and (2.3); a)
Maintain solderability (should be in accordance with GB/T125992002 C.2.2.C.2.3 and C.2.4) b)
Ensure adhesion strength (should be in accordance with GB/T125992C02 (.2.4 and (C.2.5): d) Improve corrosion resistance.
In order to avoid giving the base material or processed parts undesirable properties, such as brittleness, care should be taken in selecting the base layer. For example, high-stress nickel plating should be avoided.
If the base material is a zinc-containing copper alloy: and solderability is required, in addition to the specified tin plating thickness (should be in accordance with GB/I125992002 (.2.3), it is also necessary to make the minimum local depth of the nickel or copper base layer reach 2.5\m; this base layer is also necessary to maintain good appearance and adhesion strength.
If the base layer is determined, it is necessary The party shall specify its characteristics (should be in accordance with (Appendix () of GB/T125992002) and the minimum local repellency (should be in accordance with 10.2 of GB/T125992002), and the thickness of one or more bottom coatings shall be measured according to the method specified in Appendix A of GB/T125992002. 4.1.3 Electroplating of tin and tin alloys
Electroplating of tin and tin alloys can use sulfate or base sulfonate process, and appropriate additives should be used to obtain a coating that meets the requirements of technical standards.
4.1.4 Post-treatment
In order to improve the anti-discoloration and high temperature resistance of the coating, appropriate treatment liquid should be used for post-treatment. The water, raw and auxiliary materials used in lead-free electroplating tin and tin alloy process should not contain lead. 4.2 Production control||tt ||4.2.1 Inspection of production equipment
Before production, the operator should check whether the relevant production equipment has a qualified label or certificate, and can only be used within the validity period after verification. 4.2.2 Water quality requirements
Preparation of electroplating tin and tin alloy and post-treatment liquid, all water washing parts after electroplating should use deionized water or distilled water. 4.2.3 Water washing
In the production process, two or more water washings are carried out after each process to ensure that it is clean. 4.2.4 Bath liquid analysis
All bath liquid components should be analyzed regularly, and not less than once a week. Plating liquid impurities are analyzed once a week, and complete records are kept. 4.2.5 Filtration
The plating process should adopt continuous filtration, and the bath liquid circulation volume should not be less than four times per hour, and complete records are kept. 4.2.6 Refrigeration
Electroplated tin and tin alloy floats are prone to hydrolysis of trivalent tin due to high temperature. The plating solution should be equipped with refrigeration equipment. -rrKaeerkca-
4.2.7 Production records
GB/T 39807—2021
The processing month, name, quantity, time, current and raw and auxiliary material addition amount of the parts should be recorded during the production process. 4.3 Substitute test specimens
When it is not appropriate to use parts for destructive testing, the test specimens can be used to replace the parts. The test specimens are 150mm×100mm×1mm copper plates. The test specimens should be electroplated and treated in the same conditions as the parts they represent. 4.4 Equipment requirements
4.4.1 Power supply requirements
The power supply used for electroplating can use various DC power supplies. The rated output values ??of the total voltage and current should be able to meet the maximum voltage and current required by the plating tank under full load. The accuracy level of the voltage and current meter should not be lower than level 1.5. 4.4.2 Requirements for tanks
The tanks should be corrosion resistant to the contained solvents. Tanks for electrolytic degreasing, acid activation, electroplating, etc. should have air devices. 4.4.3 Instruments and meters
Measurement instruments, meters and base tools should all have certificates of conformity and be calibrated regularly and can only be used within the validity period. 5 Product quality requirements
5.1 Requirements for base materials
The base materials for lead-free electroplated tin and tin alloys shall meet the following requirements a) Severe oil stains, metal chips, paint layers, corrosion and scale shall be removed; h)
The surface of the parts shall be free of burrs, cracks, pressure pits and other man-made damage caused by poor operation. The surface shall be free of surface damage; welding parts shall be free of solder residues and slag; castings shall not have unremoved sand particles and paint sintering products d)
5.2 Copper and tin content of the coating
Use stainless steel as the base material to electroplate tin or tin alloy, use 1:1 nitrate to remove the surface coating, and use atomic absorption spectroscopy (or other instruments) to measure the tin, lead and copper content. The coating shall not contain 2%~4% copper in electroplated tin steel alloy, and the tin content of electroplated pure tin coating shall be greater than 0.9.05%. It can also be directly measured by electron energy spectrum.
5.3 Appearance of coating
All parts shall be inspected for appearance by daylight. The coating is silvery white or slightly light yellow, and the crystallization of the coating is uniform, delicate and smooth. The plated parts are allowed to have slight fixture marks in hidden parts. Slightly uneven color or gloss due to uneven substrate material and different surface processing conditions is allowed: the surface of the parts after high temperature inspection is allowed to be slightly yellowed. Spots, black spots, burns, roughness, holes, low spots, cracks, delamination, blistering, peeling, shedding, plating in a grainy state, and local non-plating (except in blind holes, deep through holes and tea specified in technical documents) are not allowed.
5.4 Coating thickness
Pure tin and tin alloy coatings are classified by thickness. According to the different use conditions in 7.1 of GB/T12399-2002, the provisions of the minimum serial value of each type are shown in Table 1.
Use condition number
Table 1 Coating thickness
Copper substrate after plating:
Coating grade number
(partial)
Sn33
SnlE
Minimum thickness
Base metal
Coating grade number
(partial)
Sn30
Sn20
Sn12
The bottom coating on zinc-copper alloy substrate material shall comply with the requirements of Chapter 9 of GB/T12599-2002. The requirements for the bottom coating on specific substrate materials shall comply with C.2.1 of GB/T12589-2092. and C.2.5. Minimum thickness
shall be measured according to the method given in Appendix A of GB/T12599-2002. A basic measuring surface on any part of the main surface that can be touched by a small ball with a protruding diameter of 20mm shall be measured for coating thickness according to GB/T12334. When the main surface area of ??the plated part is greater than or equal to 160mm, the minimum thickness shall be regarded as the minimum partial thickness value. When the main surface area of ??the plated part is less than 100mm, the minimum thickness shall be regarded as the minimum value of the half-average thickness. 5.5 Bonding strength
When the purchaser specifies the test according to the method given in Appendix B of GB/112599-2002, the coating should not appear Peeling phenomenon.
5.6 Solderability
5.6.1 General materials and parts
If the purchaser has requirements for solderability, the solderability test shall be carried out according to the method 1 of the Ta test in GB/T2423.28, using an inactive flux.
If accelerated aging is required before the test, the purchaser shall specify the accelerated aging process. 5.6.2 Printed circuit boards
If the purchaser has requirements for solderability, the coating on the printed circuit boards that meet this standard shall be subjected to a solderability test according to the test method in (B/T2423.28).
If accelerated aging is required before the test, the purchaser shall specify the accelerated aging process. 5.7 Porosity| |tt||If the purchaser specifies the porosity, for the coating with a minimum thickness greater than or equal to 102m, it should undergo the following tests: a) Coatings on steel substrates, in accordance with the provisions of GB/T10125; b) Coatings on non-steel substrates, in accordance with the provisions of GB/T9789: In the above two cases, when observed with a three-fold magnifying glass, the substrate should have no signs of corrosion. 5.8 Anti-discoloration performance
In a closed container, heat pure water (conductivity less than 3uS/cm) to 100℃ under normal pressure, place the T piece 1cm above the water surface, and expose it to steam for 1h. The coating does not change color
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Anti-tin whisker performance
GB/T 39807—2021
After conducting the experiment in a high and low temperature humidity test chamber at a temperature of 85℃ and a relative humidity of 85% for 1000h, there should be no whiskers when observed with a scanning electron microscope at a magnification of 200 times.
Sampling
The sampling method can be in accordance with the provisions of GB/T12609. The sampling method and acceptance level can also be agreed upon by the supply and demand parties:-rrKaeerkAca-
GB/T39807-202
National Standard of the People's Republic of China
Technology Specification for Lead-free Electroplating Tin and Tin Alloys
GB/T 39807—2021
Published and distributed by China Standards Press
No. 2, Liupingli West Street, Chaoyang District, Beijing (100029) No. 16, Lihe North Street, Xicheng District, Beijing (No. 13002) Website: pc.org.cri
Service hotline: 400-168-3010
2℃March 21 General
Book number: 155066: 165672
Copyright reserved
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Infringement will be investigated28 Ta test method 1, use inactive flux to perform solderability test.
If accelerated aging is required before the test, the purchaser shall specify the accelerated aging process. 5.6.2 Printed circuit boards
If the purchaser has requirements for solderability, the coating on the printed circuit board that meets this standard shall be subjected to solderability test in accordance with (B/T242328 T: test method,
If accelerated aging is required before the test, the purchaser shall specify the accelerated aging process. 5.7 Porosity
If the purchaser has requirements for porosity, for coatings with a minimum thickness greater than or equal to 102μm, the following tests shall be performed: a) Coatings on steel substrates shall be subjected to GB/T10 125 provisions; b) Chain layer on non-steel substrate, dial GB/T9789 provisions: In the above two cases, when observed with a three-fold magnifying glass, the substrate should have no signs of corrosion, 5.8 Anti-discoloration performance
In a closed container, heat pure water (conductivity less than 3uS/cm) to 100°C under normal pressure, place the T piece 1cm above the water surface, exposed to steam for 1h. The coating does not change color
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Anti-tin whisker performance
GB/T 39807—2021
Use a high and low temperature humidity test chamber at a temperature of 85°C and a relative humidity of 85% for 1000h, and observe with a scanning electron microscope at a magnification of 200 times. There should be no whiskers.
Sampling
The sampling method can be in accordance with the provisions of GB/T12609. The sampling method and acceptance level can also be agreed upon by the supply and demand parties:-rrKaeerkAca-
GB/T39807-202
National Standard of the People's Republic of China
Technology Specification for Lead-free Electroplating Tin and Tin Alloys
GB/T 39807—2021
Published and distributed by China Standards Press
No. 2, Liupingli West Street, Chaoyang District, Beijing (100029) No. 16, Lihe North Street, Xicheng District, Beijing (No. 13002) Website: pc.org.cri
Service hotline: 400-168-3010
2℃March 21 General
Book number: 155066: 165672
Copyright reserved
-rrKaeerkAca-
Infringement will be investigated28 Ta test method 1, use inactive flux to perform solderability test.
If accelerated aging is required before the test, the purchaser shall specify the accelerated aging process. 5.6.2 Printed circuit boards
If the purchaser has requirements for solderability, the coating on the printed circuit board that meets this standard shall be subjected to solderability test in accordance with (B/T242328 T: test method,
If accelerated aging is required before the test, the purchaser shall specify the accelerated aging process. 5.7 Porosity
If the purchaser has requirements for porosity, for coatings with a minimum thickness greater than or equal to 102μm, the following tests shall be performed: a) Coatings on steel substrates shall be subjected to GB/T10 125 provisions; b) Chain layer on non-steel substrate, dial GB/T9789 provisions: In the above two cases, when observed with a three-fold magnifying glass, the substrate should have no signs of corrosion, 5.8 Anti-discoloration performance
In a closed container, heat pure water (conductivity less than 3uS/cm) to 100°C under normal pressure, place the T piece 1cm above the water surface, exposed to steam for 1h. The coating does not change color
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Anti-tin whisker performance
GB/T 39807—2021
Use a high and low temperature humidity test chamber at a temperature of 85°C and a relative humidity of 85% for 1000h, and observe with a scanning electron microscope at a magnification of 200 times. There should be no whiskers.
Sampling
The sampling method can be in accordance with the provisions of GB/T12609. The sampling method and acceptance level can also be agreed upon by the supply and demand parties:-rrKaeerkAca-
GB/T39807-202
National Standard of the People's Republic of China
Technology Specification for Lead-free Electroplating Tin and Tin Alloys
GB/T 39807—2021
Published and distributed by China Standards Press
No. 2, Liupingli West Street, Chaoyang District, Beijing (100029) No. 16, Lihe North Street, Xicheng District, Beijing (No. 13002) Website: pc.org.cri
Service hotline: 400-168-3010
2℃March 21 General
Book number: 155066: 165672
Copyright reserved
-rrKaeerkAca-
Infringement will be investigated
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