This standard specifies the requirements for electroplated copper, nickel and chromium coatings on plastics for various conditions of use. This standard applies to electroplated copper, nickel and chromium coatings on plastic substrates, and also applies to electroplated nickel + chromium coatings on plastic substrates. GB/T 12600-1990 Electroplated copper, nickel and chromium coatings on metal covering plastics GB/T12600-1990 Standard download decompression password: www.bzxz.net
This standard specifies the requirements for electroplated copper + nickel + chromium coatings on plastics for various conditions of use. This standard applies to electroplated copper + nickel + chromium coatings on plastic substrates, and also applies to electroplated nickel + chromium coatings on plastic substrates.

National Standard of the People's Republic of China
Coating
Electroplated coatings of copper plus nickel plus chromium on plastics
Metallic coatings
Electroplated coatings of copper plus nickel plus chromium on plastics inaterialsGB 12600—90
This standard is equivalent to the international standard 1S04525-1985 "Metallic coatings - Electroplated nickel plus chromium on plastics". 1 Subject content and scope of application
This standard specifies the requirements for electroplated copper plus nickel plus chromium coatings on plastics used for various types of parts. This standard applies to electroplated copper plus nickel plus chromium coatings on plastic substrates. It is also applicable to electroplated nickel plus chromium coatings on plastic substrates. 2 Reference standards
Determination of the thickness of the coating layer of gold chips Anodic bath coulometric method GB 4955
GB6462 Microscopic measurement method for the cross-sectional thickness of metal and oxide coatings GR 646)
Accelerated acetic acid salt spray test (CASS test) for metal coatings iB9797 Gold coating Nickel + chromium and copper + nickel + chromium electroplating GB/T12610 Thermal cycle test for electroplated coatings on plastics (B12609 Count sampling inspection procedure for electrodeposited metal coatings and related finishing 3 Terminology
3. 1 Main surface
Certain surfaces of the product that have been electroplated or are to be electroplated. On this surface. 1 The coating is essential to the appearance and (or) performance of the product. 3. 2 Minimum thickness
On the main surface of a product: the minimum value of the local thickness measured. 4. Information that the purchaser should provide to the supplier
4.1 The standard number of this standard is GB 12600, 4.2 Conditions of use of the key layer, key layer classification and thermal cycle test (see Chapter 5). 4.3 Appearance requirements, such as bright, matte or satin, also called the purchaser to provide samples that can indicate the appearance requirements: 4.4 The main surface should be marked on the workpiece drawing! Or use a sample with appropriate markings to indicate: The inevitable fixture marks on the surface should also be marked.
5 Classification
5.1 Classification of use conditionswwW.bzxz.Net
The use conditions are divided into four categories according to the severity of the use environment conditions: State Technical Supervision Bureau 1990-10-18 approved in December 1991 01 Implementation
-Use for dry indoor conditions;
Use for humid indoor conditions;
-Use for general outdoor conditions:
Use for harsh outdoor corrosive conditions,
5.2 Coating Classification
Coating classification consists of the following parts in sequence PL-Plastic matrix material:
GB 1260090
A slash separates the substrate from the coating, with the substrate before the slash and the coating after it: Cu-copper coating. The number after copper is the minimum thickness of the copper coating, in um: Ni
nickel coating, the number after nickel is the minimum thickness of the coating, in μm, and the letter (primary) after the number indicates the type of nickel coating: b represents full bright nickel coating: 8 represents dark nickel, satin nickel or semi-bright nickel that does not require mechanical polishing; double-layer nickel or single-layer nickel: Cr--chromium coating. The letter (small print) after the letter indicates the type of chromium coating: t represents ordinary chromium + mc represents microcrack chromium. mp represents microporous chromium: when there is no number after the letter, it means that the thickness of the chromium layer is 0.3um. If the purchaser requires other thicknesses (see 7.%.1), the coating thickness must be indicated by a number after the word thickness
Example: PL/Cu15Ni15h Crmc
Cu plating layer 15um, bright layer 15um. Micro crack layer 0.3μm on the substrate. 5.3 Classification of thermal cycle test conditions
The temperature range of thermal cycle test is divided into three categories: A-
Upper limit temperature 75±2℃, lower limit temperature 20-5℃; B-
Upper limit temperature 75±2℃, lower limit temperature 20-2Upper limit temperature 7512℃!, lower limit temperature -10±2℃5.4 Plating use conditions, the corresponding relationship between plating thermal cycle test and plating classification is listed in Table 1. Table 1
Use conditions
6 Substrate requirements
Thermal cycle test
Plating classification
PL/Cu/5NiSh(s)Crr(or memp)
PL/Cu20Ni5B or:)Ctr(ormc,mp)PL/culSNi10b(orsd)C+(orme.mp)PL/Cu2ONil0p(orsd)Crr(ormnc.tnp)PL/CulNi20b(ors,d)Crr
PL/Cu|5Ni15bCrmc:ormp）
PI./C120N120b(or9,d)Cr
PL/Cu21Ni15bCrmc(ormp）
PL/Cu1hNi25uCrr
PL/c/15Ni25b（ors）Cmc（ormp）PL/(u20Ni25dCtr
PL/Cu20Ni2.h（or>Crme（ormp）This standard puts forward specific requirements for various types of plastics used for electroplating, but does not have any requirements on the state of the plastics. For plastic products that change, such as molded parts, it is required that the electroplating can be carried out 24 hours after the product is formed.
7 Plating requirements
7.1 Copper plating
GB12600-90
Due to the different thermal expansion coefficients of plastics and plating, in order to ensure good bonding strength between the layer and the substrate, a copper layer with good ductility is required as the bottom plating layer. The plating thickness is measured by the method specified in Article 9.1 on the main surface. The minimum thickness value shall meet the requirements of Table 1. 7.2 Nickel plating
is used as the middle plating layer or the bottom plating layer. The plating thickness is measured by the method of 9.1. The minimum thickness of the surface shall meet the requirements of Table 1. Double-layer and triple-layer nickel shall also have the properties of Table 2.
Table 2 Properties of double-layer and triple-layer nickel plating
Middle layer
Elongation rate
Comb years
y(m/m)
>0. 04 and ≤0. 15
Thickness accounts for the percentage of the total thickness of the image layer
Note: 1) The sulfur content of the bonding layer is generally controlled by the plating solution, and is measured by the method of Appendix GH 97U7 when necessary. 7.3 Chromium plating
7.3.1 Surface coating. The coating thickness is measured by the method of 9.1.2. The minimum thickness of the surface is generally 0.3um. If the appearance gloss requirement is relatively high, the thickness of the microporous chromium and microcrack chromium layer can be increased to 0.5um: if it is required to have a texture pattern, the thickness of the microcrack should be 0.8um; if the purchaser requires an increase in the thickness of the bonding layer, it should be indicated when the coating classification is proposed to the supplier, such as Crmc (0.8) Crmc (0. 5).
7.3.2 Microcrack chromium layer The number of microcracks shall be measured by method 9.3. In any direction, the number of cracks per centimeter shall be not less than 250. Microporous chromium layer The number of micropores shall be measured by method 9.3.2. The number of micropores shall be not less than 10,000 per square centimeter. 7.4 Appearance
The coating shall be fine and uniform. No visible defects such as blistering, pitting, roughness, local absence of coating, shedding, stains or discoloration are allowed on the surface.
7.5 Bonding strength
The coating shall be subjected to bonding strength test according to method 9.4. The test cycle is four thermal cycles. After the test, the coating should not have visual defects such as blistering, wrinkling, cracking or falling off. 7.6 Corrosion resistance 1
The plated parts should be subjected to corrosion test according to the method in 9.5. The test time list of various conditions is 3. After the test, there should be no defects such as copper layer corrosion, plastic substrate bleed, and coating blistering. Instructions for use:
111S4) 4525 stipulates that the corrosion level should be determined by ISO [462 rating force method, and it is required to be not less than level 8. There are some problems with the liquid-1 method, which is highly controversial in the International Organization for Standardization. This article is based on the 6.5 combined corrosion test of the standard specification for copper/metal/chrome decorative electroplating on A5TMB601-H0 material, and has been formulated after a large number of tests and verifications. 8 Sampling
Use condition number
GB 126D0—90
Table 3 Tumor corrosion test time for various use conditions CASS test duration.h
Sampling inspection of the coating shall be carried out according to the requirements of Chapter 7. Sampling shall be carried out according to the provisions of GB12609. 9 Test method
Except for the method in 9.3.2, other tests shall be carried out after the plating is completed for more than 24 hours. 9.1 Thickness determination
9.1.1Measure the thickness of each chrome layer and copper layer according to the provisions of GB 6462. 9.1.2Measure the thickness of chromium and total nickel layer according to the provisions of GB4955. 9.2 Ductility test
9.2.1 Preparation of specimens
Put a polished copper sheet with a length of at least 200 mm, a width of at least 60 mm and a thickness of 1 mm under the same conditions as the plated piece, and plate a 25 um thick nickel coating on one side of the copper sheet. Then cut off at least 25 mm of the edge of the specimen, so that the specimen is 150 mm long and 10 mm wide, and the edges of the specimen are rounded.
9.2.2 Test
Bend the specimen 180° on a fixed circular shaft with a diameter of 11.5±0.1 mm until the two ends of the specimen are parallel to each other, so that the electrical key surface is under tension. The pressure applied during the debending should be stable, and the contact between the specimen and the circular shaft should be ensured. 9.2.3 Evaluation of test results
After the test, observe the convex surface of the bent specimen. If there is no crack that completely breaks, it can be considered that the ductility of the coating will not be less than 8% and is qualified. Small cracks appearing on the edge cannot be used as a basis for elongation not meeting the requirements. 9.3 Determination of the number of microcracks and micropores in the coating
Microcracks generally do not require pretreatment and can be directly observed under a microscope. Only in controversial cases, the copper deposition method is used to display the cracks first. Micro-chromium must be pretreated using the copper deposition method. 9.3.1 Determination of the number of microcracks by microscopy
Under an optical microscope, measure the number of cracks on the surface of the chromium layer. 9.3.2 Copper deposition method for displaying microcracks and micropores Deposit a copper layer on the workpiece that has just been plated with chromium under the following conditions: Copper sulfate (CusO.5H,O)
Sulfuric acid (H,SO)
Cathode current density Dk
Deposition time
20±5℃
0. 3 A/dm2
Rinse the sample, dry it in air, and measure the number of microcracks and micropores under a microscope. When this test is carried out a few days after chrome plating, the sample must first be immersed in a nitric acid solution containing 10~20g per liter at a temperature of about 65℃ for 4 minutes. 9.4 Thermal Cycle Test
Carry out the bonding strength test in accordance with GB/T12610, 9.5 Corrosion Test
Carry out the corrosion resistance test in accordance with GB 6160. Additional Notes:
CB12600-90
This standard was proposed and approved by the National Technical Committee for Standardization of Metal and Non-metallic Coverings, and this standard was drafted by the Guangzhou Electrical Science Research Institute of the Ministry of Machinery and Electronics. The main drafters of this standard are Chen Qicheng, Luo Qingying, Jiang Guozhao,
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