GB/T 4722-1992 Test methods for copper-clad laminates for printed circuits
Some standard content:
UDC621.316.616-415:621.3.049.75L80
National Standard of the People's Republic of China
GB/T4721~4722—92
GB 4723~472592
Copper-clad laminated sheetsfor printed circuits
1992~07-08 Issued
National Technical Supervision Bureau
1993-04-01 Implementation
National Standard of the People's Republic of China
Test methods for copper-clad laminated sheets for printed clrcuits
GB/T 4722—92
Replaces 094722—84
This standard refers to and adopts the international standard IFC249-1 (1982) "Metal foil base materials for printed circuits Part 1: Test methods. 1 Subject content and scope of application
This standard specifies the test methods for electrical, mechanical and other properties of copper foil laminates for printed circuits. This standard is applicable to the performance testing of various copper foil laminates for printed circuits (hereinafter referred to as foil laminates). 2 Reference standards
GB1409 Relative dielectric band number and dielectric loss factor of solid electrical insulating materials at power frequency, audio frequency, high (including meter wavelength)
B2423.3 Environmental test procedures for electrical and electronic products Test Ca: Steady-state damp heat test method GB2423.28 Basic environmental test procedures for electrical and electronic products Test T: Determination of comparative tracking index and leakage tracking index of solid insulating materials for soldering under humid conditions GB4207
Printed circuit name Test terms and definitions
G B2035
Part I General Requirements
3 Test Specimens
3.1 Preparation of Test Specimens
3.1.1 Cleaning and Printing Test Patterns
3.1.1.1 If a test pattern needs to be made, process the cover plate into the required size. The copper foil surface of the test foil plate should be cleaned with abrasive powder (such as pumice powder) mixed with water (if necessary, add sodium phosphate for cleaning) until an unbroken water film is formed on the entire copper foil surface. Then immerse it once in a 10% hydrochloric acid solution, remove the surface moisture with water and dry it. 3.1.1.2 For the cover plate that has been cleaned as above, print the test pattern on the copper foil surface using a method that can obtain the specified accuracy. 3.1.2 Etching Method
3.1.2.1 Whether it is to make a test pattern or to support the entire copper foil, it is necessary to use an appropriate single etching method for etching (such as copper chloride, etc.). When there is a dispute between the supply and demand parties, the spray method is used to etch with a ferric chloride aqueous solution with a density of 1.32~~1.418/cm. The liquid overflow shall not exceed 37%. The etching time is determined by obtaining a clear test pattern. The maximum etching time shall not exceed the provisions of Table 1. Approved by the State Administration of Technical Supervision on July 8, 1992 and implemented on April 1, 1993
Nominal thickness of short foil
Maximum etching time!
GE/T 4722
Etching time of steel sheet
Note: 1) For products with a nominal thickness between the two specifications in Table 1, the maximum etching time shall be determined by the linear internal method. 3.1.2.2 If copper particles still remain in the non-patterned part of the sample after the specified etching time, the sample shall be discarded. 3.1.3 Cleaning and drying after etching
3.1.3.1 After etching, the sample should be immediately rinsed with running cold water with a resistivity of not less than 10Ω.m for 5 minutes, scrubbed or soaked with 10% oxalic acid solution for 5 minutes. Then rinsed with running cold water with a resistivity of not less than 10Ω.m for 10 to 20 minutes or rinsed until the surface dirt is removed.
After etching and rinsing, the sample with test pattern should be removed with a soft brush with appropriate solvents such as butanone, trifluoroethylene, toluene, etc. or other suitable methods. Then, use abrasive powder (such as pumice powder) mixed with water to clean with the help of a plastic brush until an unbroken water film is formed on the surface of the sample, scrubbed or soaked with 10% oxalic acid solution for 5 minutes, and then rinsed with running cold water for 10 to 20 minutes, or rinsed until the grease is removed. In the process, attention should be paid to reducing the scratches on the bonding surface to a minimum. 3.1.3.2 The sample is washed with water of not less than 1000Q·m for 3 times (replace with clean water each time), each time for 2 minutes. Then wipe off the moisture on the surface of the sample and put it into an oven at a temperature of 55±2℃ to dry for 4h10min. Then take the sample out of the oven and store it in a desiccator until it is processed in accordance with relevant regulations. All tests should be carried out within three months after the sample is taken out of the oven. The number and size of the sample are as shown in Table 2. Table 2 Number and size of samples
Sheet foil resistance
Test items
Constant adverse treatmentRecovery in humidity chamber) and
Surface resistivity and area resistivity under high temperatureSurface corrosion
Edge corrosion
Comparative tracking index
Constant condensation heat treatmentDielectric strip number and dielectric loss constant after recovery
Insulation resistance in parallel directionbZxz.net
Vertical to the board surface Electrical strength
Warp
Pull-off strength
Number of samples
i10 pads
Test size
About 330×（250.2）
(190±1)×(100=1)
（100±1)×（150=1)
(2±0.5)×(25±0.5)
50× 5c
≥(8-4H)( for thickness)
275×50
（100±1)×（100±1)
Original size of test plate thickness 20.8
Width 220
Peel strength
Test items
, after thermal shock
b, after dry heat
c. After exposure to solvent vapor
d. After exposure to simulated electroplating parts
e. After soaking in solvent
1. At high temperature
Blistering test after thermal shock
Punching
Surface appearance
Fragility
Dimensional stability
Copper foil mass per unit area
Verticality
Bending strength
Flammability
Horizontal burning method
Vertical burning method
Water absorption
Note: 1) Cut the sample into four strips and test them separately. Sample treatment and test conditions
CB/T 4722--92
Continued Table 2
Number of samples
1, (4 strips)
1. (4 strips)
1. (4 1, (4 strips)
1, (4 strips)
1, (4 strips)
2 on each side
Wet each side center, half wet each side [0
Vertical and horizontal directions
10 or 10, F-
Sample size
(75±1)×<50±1)
(75±1)×(50±1)
(75±1)×(50±1)
(75±1)X(50±1)
(75±1)X(50+1)
(75±1)X(50±1)
(25±1)X(2=1)
(70 on 2) ×(55±2)
Thickness 1.6 or 1.5
Original size of the test pole
(30±1)×(30=1)
About 300×300
[100± 1)X(100.1)
Original size of the test plate
Original size of the test plate
Length: 1620
Width: 25±0 when I = 1 ~3, 5 when II >8, 15±0. 5
No test when H1
(H is degrees)
(125+5) :(13=0. 5)
(125±5)×13 :0.5)
(50±1)×(50=1)
(75=1)X(5G=1)
The treatment conditions for the test mix are specified in the various performance test methods and product standards. This standard specifies several treatment conditions and test conditions as follows:
4.1 Standard atmospheric conditions
4.1.1 The test atmospheric conditions for the positive belt are temperature 15~35℃, relative humidity 45%~75%, and air pressure 86~106kPa. 4.1.2 The standard atmospheric conditions for the test are temperature 23±1℃, relative humidity 48%~52%, and air pressure 86~106kPa. 11
4.2 Controlled recovery conditions
GR/T 4722—92
Controlled recovery conditions are actual test chamber temperature ±1°C, but within the range of 15~35°C, relative humidity 73%~77%, air pressure 86~106 kPa.
4.3 Pretreatment conditions
The specimen is placed in a temperature of 15~35°C, relative humidity 45%~75%, and air pressure 86~106 kPa for no less than 16 hours (for electrical performance test, the test mixture is no less than 24 hours, and the surface of the specimen is prevented from being contaminated). 4.4 Normal test
After pretreatment, it is carried out under normal test atmospheric conditions. 4.5 Steady humidity test
Perform according to G2423.3 Test Ca. The specimen is placed in an environment with a temperature of 40±2°C and a relative humidity of 90%~95% for 96±1 hours (including the recovery time). According to the provisions of the product standard, after testing in the wet heat box, or after being taken out of the wet heat box, it should be immediately placed in the controlled recovery conditions for verification, the time is 90±15mia, and the test should be carried out immediately after being taken out from the recovery conditions. 4.6 Hot test
The processing conditions (temperature, time and medium) of the hot test are specified in the test procedure of the specific test item or in the product standard. If the time is not specified, it is generally kept in the hot state for 60+min, and then tested in the hot state. 5 Test records
In addition to the record content specified in the specific test method, the following items should be recorded during the test: sample model, name, batch number, manufacturing date and manufacturing unit or test unit: a.
Model and name of the test equipment:
Sample processing and test environment conditions,
Test results and calculated values\:
Test period and tester.
Note: 1) The accuracy of the test value, unless otherwise specified, the test result obtained should be expressed with the same number of significant figures as the indicator. Part II Electrical Performance Test Methods
6 Copper Foil Resistance Test Method
6.1 Method Summary
This method uses the principle of constant current source and 4-terminal measuring disc to measure the copper foil resistance of the copper foil plate and the copper box for the foil plate to evaluate its conductive performance. 6.2 Test Equipment
6.2.1 A micro-ohmmeter with a minimum reading of 0.01m or a 0.05-level DC bridge is used. During measurement, the current is as small as possible so that the temperature rise of the copper foil does not exceed 1C.
6.2.2 The measuring tool can use a line contact fixture or a point contact fixture. 6.3 Samples and their preparation
Cut 4 samples with a length of about 330mm and a width of 25±0.2mm from the tested steel foil or the tested foil-coated plate. 6.4 Test Procedure
6.4.1 The sample should be placed so that the copper foil surface maintains good contact with the measuring tool. When the line contacts, it should cross the entire box width and contact the foil, and be perpendicular to the long axis of the sample.
6.4.2 Apply current between the contacts 300mm apart, and measure the electrical conductivity of the copper foil between the contacts 150±1mm apart, as shown in Figure 1. The measurement results are expressed in milliohms.
GB/T 4722-92
150 ±1
About 330
Figure 1 Schematic diagram of four-contact measurement of copper foil resistance
1,4-power contact F3.3-measurement contact 15 sample 6. 4.3 Measure the test environment temperature, and correct the measured resistance value to the resistance value at a temperature of 20°C. For the conductivity of % of the national standard annealed copper standard ([·A·C·S) ship, the correction coefficient is obtained by formula (1):!
1+ 0.003 78(20)
Where: , — ambient temperature, ℃.
The point values between 15 and 35℃ are given in Table 3. Table 3 Correction coefficient of resistance
Temperature
Correction coefficient
6.5 Calculation and evaluation of test results
Temperature!
According to the positive coefficient
6.5.1 Multiply the measured value by the correction coefficient, and the result is the resistance value at 20℃. 6.5.2 The largest resistance value among the four resistance values measured and corrected is taken as the test result. 7 Test method for surface resistance and volume resistivity after recovery from constant humidity and heat treatment and at high temperature 7.1 Summary of the method
Temperature:
Correction coefficient
0-948
This method applies a DC voltage to the sample after recovery from humidity and heat treatment or at high temperature, measures the leakage current through the surface of the sample or through the inside of the sample, and expresses the insulation performance of the residual box board in terms of surface resistance and volume resistivity. 7.2 Test instruments, equipment and their requirements
7.2.1 A humidity and heat test chamber that meets the requirements of Article 4.5. 7.2.2 A constant temperature chamber that can control the temperature of ±2°C. 7.2.3 Any instrument for measuring insulation resistance with a measurement error not exceeding 20%. 13
CB/T 4722—92
7.2.4 The electrode adopts a three-electrode system. The copper foil electrode can be connected with a connecting wire or a spring contact or an auxiliary electrode made of metal. The laminate surface of the single-sided box-clad board or the double-sided foil-clad board is completely etched away from one side of the copper foil. An annealed pigeon box or tin box electrode with a thickness not exceeding 0.2mm is used. A small amount of medical vaseline (silicone ester is used for high temperature tests) is pasted on the sample. No air gap or impurities are allowed. The lead pin or tin box electrode must be flat and free of damage. The manufactured electrode must not have a hair agent and is connected with an auxiliary electrode made of gold. A conductive rubber electrode can also be used.
7.2.5 A vernier caliper with a scale not greater than 0.1mm. 7.2.6 A stopwatch or a timer in seconds. 7.3 Test specimens and their preparation
7.3.1 Cut a square specimen with a side length of 100±1 mm and a thickness equal to the original thickness of the test plate from the test box plate. Take 4 specimens after constant heat treatment and 4 specimens for high temperature test. The surface resistance and volume resistance of the disc are measured on the same specimen. 7.3.2 Prepare the standard pattern specimen of the ring disc assembly shown in Figure 2 according to Chapter 3. If the specimen is copper-plated on both sides, the foil on the other side should be completely etched off.
Figure Ring disc plastic table standard pattern test
7.4 Test procedure
7.4.1 For the specimens that have been pretreated and the thickness has been measured, perform constant wet heat treatment according to Article 4.5, or perform hot treatment according to Articles 1 and 6. Resistance measurement after constant condensation heat treatment, that is, the sample is taken out of the wet heat test box and restored in controlled recovery conditions. After the sample is taken out from the recovery conditions, the resistance is measured within 5 minutes. After the supply and demand parties agree, the sample can also be measured in the heat test box after strong heat treatment.
7.4.2 Hot resistance measurement, after the sample is treated in the constant temperature box, keep it in the test box for resistance measurement. 7.4.3 Connect the three-electrode system according to Figures 3 and 4, and use the insulation resistance measuring instrument to measure its surface resistance and volume resistance. The test voltage applied is DC 500 ± 50Y, and the reading is read after 1 minute of power on. 14
7.5 Calculation and evaluation of test results
7.5.1 Calculation
Surface resistance R. Expressed in megohms.
CB/T 4722—92
77777777772777774
Figure 3 Three-electrode assembly for measuring surface resistance
1 Ammeter and shunt; 2 Sample
Figure 3 Three-electrode assembly for measuring surface resistance
1--Ammeter and shunt 2--Sample
Volume resistivity P, expressed in megohm-meters and connected (2) Calculation: e = R (D+d)?
Where; D--inner diameter of the guard electrode, m;
-diameter of the measuring electrode, m,
-thickness of the test electrode+ml
circumference, take 3.14;
Volume resistivity+Ma.
7.5.2 Evaluation
The minimum value among the four samples shall be taken as the test result. In the test report, whether the constant humidity test is conducted in the box or after recovery should be stated.
B Surface Etching Test Method
8.1 Method Summary
GB/T 4722-92
This method is used to evaluate the quality of the foil by passing a true current through the sample and examining the etch performance of the insulating substrate and conductor under mixed heat conditions.
8.2 Test equipment
8.2.1 Thermal test box that meets the requirements of Article 4.5. 8.2.2 Constant temperature box that can control the temperature ±2℃ 8.3 Test specimens and their preparation
8.3.1 Cut four square specimens with a side length of 100±1mm and a thickness equal to the original board thickness from the test cover board. 8.3.2 Prepare the standard pattern specimen of the ring and disk combination shown in Figure 2 according to Chapter 3. If the specimen is a double-sided board, the copper foil on the other side should be completely etched away.
8.3.3 The connecting wire should be welded to the ring and disk. The welding point should be 5±0.5mm away from the electrode gap 8.4 Test procedure
The specimen is subjected to a constant damp heat test according to Article 4.5 for 21 days. During the entire period when the specimen is covered under damp heat conditions, a DC voltage of 100±5V is applied between the ring and the disk through a resistor so that the current does not exceed 1mA. 8.5 Evaluation
After the test cycle is over, the power supply is cut off. Take the sample out of the heat test chamber, check immediately whether there are visible corrosion products between the ring and the disk, and make a detailed record. If one of the four samples has corrosion products, it is judged that there are brain corrosion products in the gap. 9 Edge corrosion test method
9.1 Method summary
This method uses the principle of electrochemical corrosion to determine the extent of electrochemical corrosion of the metal parts in contact with the cover plate under polarization voltage and condensation conditions due to the substrate
9.2 Test equipment
9.2. 1 The edge corrosion device is shown in Figure 5. Figure 5 Schematic diagram of edge brain corrosion device
1-Insulator: 2-Electrode, 3-Yellow steel sheet 14-Sample; 5-Yellow sheet; 6-Inlay point: 7-Adjusting screw + 8-Positive electrode; 9-Inflammable electrode
CB/T 4722--92
9.2.2 The specification of brass electrode sheet is H6210mm×30mm×0.1mm. Its preparation method is to use low boiling point straight chain hydrocarbon (such as carbon tetrachloride, etc.) to remove oil stains in the test box, and then wipe the surface with fine-grained aluminum oxide and 0.35g/cm3 ammonia solution (relative density of liquid is 0.880.91>). Then use denatured ethanol solution containing 0.10g/cm3 ferric chloride and 10% industrial Hydrochloric acid solution is used for pickling (roughening). The degree of pickling can be controlled by adjusting the pickling time until the brass foil has a uniform dull luster. Then, immerse the foil in ethanol, finally take it out, dry it with filter paper, and cut it according to the specifications of the electrode sheet. After the roughening, the roughened surface of the electrode sheet must not be touched directly by hand. 9.2.3 A damp heat test chamber that meets the requirements of Article 4.5. 9.2.4 3 to 5 times magnification.
9.2.5 Suitable pressure tester .
9.2.6 A thermostat capable of controlling the temperature of ±2°C. 9.3 Test specimens and their preparation
9.3.1 Cut four square specimens with a side length of 25±0.5mm and a thickness equal to the original thickness of the test plate from the test box plate. For plates with a thickness of 4mm or more, add 1. to 4±0.2mm.
9.3.2 Etch out the copper mold completely according to Chapter 3, and polish the edge of the coin with water-abrasive sandpaper with a grit of 700 to 800, and clean it. , blow down and set aside. 9.4 Test Procedure
9.4.1 Place the edge corrosion test device with the electrode sheet in place in a constant temperature box at 4245℃, pre-bake for 2l, take it out, install a sample on each, and tighten the yellow steel foil electrode, with the pressure controlled at about 10N/cm\. 9.4.2 The sample is subjected to a constant humidity and heat test according to Article 4.5, for 96±1h. During the entire period when the sample is placed under humidity and heat conditions, connect the electrode wire to 100±5 V DC power supply, the specific current is controlled below 1 mA. 9.4.3 After the constant humidity test, take out the brass electrode, cool it to room temperature, and use a magnifying glass to observe the degree of corrosion of the contact part between the electrode and the sample.
9.5 Test results and evaluation
9.5.1 The appearance of the brass foil of the positive and negative electrodes is evaluated according to the grading standard in Table 4. The corrosion diagram in the table is the maximum corrosion that can be allowed. 9.5.2 Take the most serious corrosion evaluation level in each group of 4 samples as the test result. Table 4 Corrosion level of brass foil
No change
Slightly red (beginning to lose)
Severely red (loss increases) and (or) with green spots of corrosive products
1.6--4mm thick sample abrasion diagram + 1.5mm thick and below sample erosion diagram level
No change
GB/T 4722—92
Continued Table 4
1.6~4nm thick sample magic corrosion map
slightly brown, with small spots or streaks visible (oxidation of alcohol layer)
brown spots (oxidation will be thicker) with isolated black spots (stronger ripening in the back) may be accompanied by the color of 1.2 and 1.4 levels
black spots increase, local oxidation is enhanced) may be accompanied by the color of 1.2 and 1.4 levels
black is dominant, black spots are inconsistent (oxidation is expanded), may be accompanied by the color of 1.2 and 1.4 levels. Grade 4 samples
The entire surface in contact with the sample, black spots are almost continuous, patches (severe oxidation extension), may still be accompanied by brown areas. Continuous black, obviously extending beyond the surface in contact with the sample (extremely severe oxidation extension), may still be accompanied by brown areas.
Note: If black and brown appear together on the negative electrode, the bottom etched is generally determined according to the amount of color. 10 Comparative leakage blistering test method
10.1 Method summary
1.5 mm thick and below sample brain etched map
This method determines the resistance of the insulating substrate surface of the cover board to surface blistering when exposed to water and other contaminants in an electric field. 10.2 This test is carried out in accordance with GB4207, using platinum electrodes. If the test is carried out on the cover surface of the sample, the copper foil should be completely etched out according to Chapter 3. 11 Test method for dielectric constant and dielectric loss factor after recovery from constant humidity and heat treatment 11.1 Summary of the method
This method uses the principle of measuring capacitance under high-frequency electric field to measure the sample after heat treatment and calculate the dielectric constant and dielectric loss factor.
11.2 Requirements for materials
Use a slow-annealed aluminum foil with a thickness not exceeding (.02 mm) as the electrode. Use a material with low dielectric loss such as medical thixotropy, silicone vinegar, etc. to attach the aluminum foil to the sample. After the foil is attached, no air gap or wrinkles should be visible. 11.3 Test instruments, equipment and their requirements
11.3.1 The electrode stack adopts a two-electrode system. Its requirements are in accordance with GB1409. The electrode device should be clean and its own dielectric loss should be as small as possible. 18
GB/T 4722-92
11. 3.2 Use a Q meter or other appropriate measuring instrument to measure the dielectric constant at 1 MHz Lower the test plate. 11.3.3 A damp heat test box that meets the requirements of Article 4.5. 11.4 Test specimens and their preparation
.1.4.1 Cut 4 test specimens from the test foil plate. The shape of the test specimens is circular, and the diameter is 50mm+4H or more or 38mm+H or more, where H is the test fence thickness (mm). The thickness of the test specimen is generally not more than 3mm. A 50mm square test specimen can also be used. When stretching, it is specified to use a toilet-shaped test specimen.
11.4.2 Etch away all the copper foil in accordance with Chapter 3. 11.5 Test sequence
11.5.1 The test is carried out in accordance with the provisions of Article 4.5 Steady damp heat test (including recovery). The test specimens in the box are not allowed to be stacked. 11.5.2 According to GB 1409 and calculate the test results. 11.6 Evaluation of test results
Take the arithmetic average of the dielectric constant and dielectric loss constant of the 4 samples as the test result. 11.7 Others
When the sample has very small dielectric absorption, the variable current method can be used for measurement. The test method is in accordance with GB1409. 12 Parallel layer insulation resistance test method
12.1 Method summary
This method uses the principle of micro-current measurement to apply a certain DC voltage between the two electrodes of the sample, measure the leakage current of the sample, and calculate the insulation resistance.
12.2 Test instruments, devices and their requirements
12.2.1 Any instrument for measuring insulation resistance with a measurement error not exceeding 20%. 12.2.2 The electrode is made of copper or steel with a diameter of 5 mm and a taper of 2%. The surface roughness parameter R of the electrode working surface is: 0.63 rn1.
12.2.3 Drill with a diameter of 5 mm; tapered reamer with a diameter of 5 mm and a taper of 2% and drilling machine. 12.2.4 Stopwatch or timer in seconds. 12.3 Test specimens and their preparation
12.3.1 Cut four test specimens from the test cabinet board with a length of not less than 75 mm, a width of not less than 5 mm and a thickness equal to the original board thickness. The test shall not be conducted if the nominal thickness of the cabinet board is less than 0.5 mm. 12.3.2 Etch out the copper box completely according to Chapter 3. 12.3.3 After etching, drill and taper the sample according to Figure 6. The taper direction of the two holes is the same, and the center distance of the holes is 25 ± 1 mm. When drilling and tapping the sample, the hole and its nearby parts must not be damaged (such as cracks, delamination, damage, etc.). The protruding part of the hole edge caused by drilling is allowed to be repaired by appropriate methods.
Tip: This standard content only shows part of the intercepted content of the complete standard. If you need the complete standard, please go to the top to download the complete standard document for free.