This standard specifies the test method for the covering ability of electroplating solutions. This standard is applicable to all types of electroplating solutions. JB/T 7704.2-1995 Electroplating solution test method Covering ability test JB/T7704.2-1995 Standard download decompression password: www.bzxz.net
This standard specifies the test method for the covering ability of electroplating solutions. This standard is applicable to all types of electroplating solutions.

Mechanical Industry Standard of the People's Republic of China
Test Methods for Electroplating Solutions
Test for Covering Capacity
1 Subject Content and Scope of Application
This standard specifies the test method for the covering capacity of electroplating solutions. This standard is applicable to all types of electroplating solutions.
2 Terminology
JB/T 7704.2--95
Covering capacity: The ability of the plating solution to deposit metal in the concave or deep hole of the cathode surface under specific electroplating conditions. 3 Principle of the Method
According to the principle of electroplating current distribution, a cathode with deep concave and outer shape obstruction or inner hole is artificially manufactured, and electroplating is carried out in the tested plating solution in an appropriate hanging manner. The covering capacity of the plating solution is evaluated by the measured area covered by the coating or the depth of plating. Different test methods will produce different results. If you want to compare the covering capacity of different key solutions or process conditions, you must use the same method and conduct the test under the same conditions. 4
Test method
4.1 Right-angle cathode method
This method is suitable for measuring the covering ability of electroplating solutions with poor performance. 4.1.1 Test instruments and equipment
Power supply: DC power supply. It is best to use a constant current power supply: Plating tank: Select a rectangular tank of appropriate size and volume; Anode: Anode material of appropriate area that meets national standards: Cathode: Use a thin steel sheet or copper sheet to make a right-angle cathode as shown in Figure 1, and insulate its back. Figure 1
Right-angle cathode
Approved by the Ministry of Machinery Industry on June 20, 1995
Implemented on January 1, 1996
4.1.2 Test device
JB/T 7704. 2-95
The device for measuring the covering ability of the plating solution is shown in Figure 2. 50mm
Figure 2 Right-angle cathode method test device
1-Power supply: 2-Ammeter; 3-Plating tank: 4-Right-angle cathode: 5-Anode 4.1.3 Test steps
4.1.3.1 Pour the plating solution to be tested into the plating tank-keep the temperature constant according to the plating solution process conditions. 4.1.3.2 After the cathode and anode are subjected to conventional pre-plating treatment, install the wiring as shown in Figure 2. 4.1.3.3 According to the plating solution process conditions, select appropriate current intensity and plating time for electroplating. After plating, remove the cathode, clean it, dry it, and then measure it.
4.1.4 Test results
The coverage ability of the plating solution is evaluated by the percentage of the coating coverage area on the right-angle cathode. The larger the percentage value, the better the coverage ability of the plating solution. 4.2 Inner hole method
This method is suitable for electroplating solutions with good coverage ability. 4.2.1 Test instruments and equipment
a. Power supply: same as 4.1.1a;
Plating tank: same as 4.1.1b;
Anode: same as 4.1.1c;
Cathode: low carbon steel tube or copper tube of 10mm (inner diameter) × 100mm or 10mm (inner diameter) × 50mm. d.
4.2.2 Test device
The cathode has different hanging methods. According to the properties of the plating solution to be tested, the cathode can be placed horizontally so that the central axis of the tube is perpendicular to the anode (as shown in Figure 3a), or it can be placed vertically so that the central axis of the tube is parallel to the anode (as shown in Figure 3b). You can also use a 10mm×50mm cathode to block the inner hole at one end (i.e. form a blind hole) and place it horizontally so that the central axis of the inner hole at the other end is perpendicular to the single anode (as shown in Figure 3c). 6
4.2.3 Test steps
JB/T 7704.2-95
Figure 3 Devices for different cathode suspension methods (dimensions in mm) 1-power supply; 2-ammeter; 3-plating tank: 4-cathode; 5-anode 4.2.3. Inject the plating solution to be tested into the plating tank and keep the temperature constant according to the plating solution process conditions. 4.2.3.2 After the cathode and the electrode are subjected to conventional pre-plating treatment, place the cathode in accordance with one of the applicable methods specified in 4.2.2 and connect the circuit. 4.2.3.3 According to the plating solution process conditions, select appropriate current intensity and plating time for electroplating. After plating, remove the cathode, clean it, dry it, and then measure it.
4.2.4 Test results
Cut the plated tubular sample longitudinally and measure the length of the plating layer on the inner hole wall of the cathode (i.e., the plating depth). The covering ability of the plating solution can be evaluated. The ratio of the plating depth to the inner hole diameter of the cathode can also be used to evaluate the covering ability of the plating solution. The larger the ratio, the better the covering ability of the plating solution. 4.3 Parallel cathode method
This method is only applicable to the determination of the covering ability of chromium plating solution. 4.3.1 Test instruments and equipment
Power supply: the same as 4.1.1a:
Plating tank: the same as 4.1.1b;
Anode: 50mm×40mm lead-tin anode (containing 10%-30% tin)Cathode: Two 40mm×20mm thin copper sheets are made into parallel cathode plates with a spacing of 10mm (see Figure 4). 20
Figure 4 Schematic diagram of parallel cathode
1--Plastic or organic glass: 2-Parallel cathode4.3.2 Test device
JB/T 7704. 2 -- 95
The device for determining the covering ability of the plating solution is shown in Figure 5. Figure 5 Parallel cathode method test device (dimensions in mm) 1- power supply; 2- ammeter: 3- plating tank: 4- parallel cathode: 5- anode 4.3.3 Test steps
4.3.3.1 Pour the plating solution to be tested into the plating tank and keep the temperature constant according to the plating solution process conditions. 4.3.3.2 After the cathode and cathode are subjected to conventional electroplating pre-treatment, install and connect them as shown in Figure 5. 4.3.3.3 Charge the cathode into the tank and electroplate for 10 minutes under the electroplating process conditions. Take out the cathode and measure after cleaning and drying. 4.3.4 Test results
Disassemble the parallel cathode after plating and evaluate the covering ability of the plating solution by the percentage of the coating coverage area on the inner side of the cathode sample. The larger the percentage value, the better the covering ability of the plating solution. 4.4 In addition to the above determination methods specified in this standard, other appropriate test methods that can evaluate the covering ability of the plating solution can also be selected through negotiation according to the properties of the plating solution to be tested, such as the hole method of making cathodes with holes of the same inner hole diameter and different depths, or the inner hole method of making a series of cathodes with different inner hole diameters.
Test report
The test report should generally include the following contents: a.
Name and model of the plating solution to be tested;
This standard number and the test method used:
Test instruments and equipment:
Test conditions:
Test results:
Test date and test personnel. bZxz.net
Additional remarks:
This standard was proposed by the National Metal and Non-metal Covering Standardization Committee. This standard was drafted by the Wuhan Materials Protection Research Institute of the Ministry of Machinery Industry. The main drafter of this standard is Zhong Lichang.
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