Test method for dynamic relating to vacuum gas emission properties of electronic material
Some standard content:
Ministry of Machinery and Electronics Industry of the People's Republic of China Standard SJ3234-89
Dynamic test method for vacuum outgassing performance of electronic materials Published on February 20, 1989
Implemented on March 21, 1989
Approved by the Ministry of Machinery and Electronics Industry of the People's Republic of China Ministry of Machinery and Electronics Industry of the People's Republic of China Standard Dynamic test method for vacuum outgassing performance of electronic materials 1 Subject content and scope of application
1.1 Subject content
This standard specifies the "dynamic flow conductivity method" to determine the outgassing amount, outgassing rate and outgassing composition. 1.2 Scope of application
SJ3234-89
This standard is applicable to the dynamic analysis of the outgassing amount, outgassing rate and outgassing composition of electronic materials in a vacuum environment by thermal desorption.
2 Objective
By measuring the vacuum degassing performance of electronic materials, the degassing process of the surface and interior of electronic materials can be deeply studied to guide production and scientific research.
3 Method Summary
This method adopts the "dynamic conductance method, which is to place the material in the sample chamber and release it under the condition that the effective pumping speed at the outlet of the flow guide is much greater than the conductance value, and the dynamic curve of the pressure change in the sample chamber with time is measured, thereby calculating the degassing volume and degassing rate, and using a mass spectrometer to measure the harmonic diagram to calculate the composition and partial pressure. 4 Equipment and Instruments
4.1 Test System As shown in Figure 1,
The virtual area can be baked
Figure 1 Schematic diagram of the test system
1—Sample chamber, made of Φ30~40mm quartz tube, tilted, and its tilt angle is 30°~45°; Machine of the People's Republic of China Approved by the Ministry of Machinery and Electronics Industry on March 20, 1989 and implemented on March 25, 1989
SJ3234--89
2-Thermocouple, using platinum-platinum or nickel-chromium-nickel-aluminum3-High temperature furnace, isothermal interval not less than 10cm4-Sample chamber;
5-Injection flange;
6-Ultra-high vacuum ionization gauge;
7-Quadrupole mass spectrometer probe;
8 Ultra-high vacuum valve;
9 small hole flow conductance, 1~2L/S.
The volume of the sample chamber is 1~2L, and the sample chamber should not be affected by the temperature of the high-temperature furnace and oven. 4.2 Vacuum mass spectrometer
Quadrupole mass spectrometer,
Mass number M: 1~100
Sensitivity S:>5×10~A/P
Resolution (
10%>150
|Scanning speed: scanning time is not more than 1s. 4.3 Ultra-high vacuum ionization meter
Range: 1×10-2~1×10-Pa.
Regulated emission current: 10~100uA,
4.4 Recorder
One standard recorder and one fast recorder, ordinary recorder: fast range 10mV/cm10V/cm, full response time is not more than 1s. Fast recorder: range 1mV/cm~10V/cm, full response time is not more than 1ms: (can also be replaced by a microcomputer connected to a quadrupole mass spectrometer). 4.5 Overflow program controller
With program heating and heat preservation functions,
The heating rate can be arbitrarily selected between 4~10℃/min, and the heat preservation value can be arbitrarily selected between 2001100, with an error of +1℃, 4.6 Exhaust system||tt ||The exhaust system should have no selectivity and "memory effect" for gases and be able to obtain clean vacuum. The effective pumping speed Sr at the outlet of the small hole flow guide should be greater than 50 times the known flow guide F. It is recommended to use a diffusion pump. 4.7 The sensitivity of the analytical balance
should not exceed 0.1mg.
5 Test steps
5.1 Sample preparation
5.1.1 Sampling
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8. According to the type, property and gas-containing disk of the material, take a certain amount of sample as a test sample and perform the operations of 5.1.2 to 5.3.1.
b According to the test results of the test sample, determine the size, weight and range of the ultra-high vacuum gauge of the sample. 5.1.2 Sample processing
a. Degrease and clean the raw materials;
b. Special materials or parts are processed according to requirements. 5.1.3 Weigh the sample with an analytical balance.
5.1.4 After processing, place the sample in the sample chamber of the test system immediately to avoid contamination. 5.2 Preparation before testing
5.2.1 Open the sample inlet flange of the test system, place the sample in the sample chamber, and then seal the flange. 5.2.2 Evacuate the test system. When baking and degassing, the temperature of the high-temperature furnace should be higher than the experimental temperature, but the sample chamber should be at room temperature. After the test system is cooled, the ultimate vacuum degree should be higher than 7×10-p. After each experiment is completed, the system vacuum degree should not be lower than 7×10-p..
5.2.3 30 minutes before the test, turn on the power of all instruments for preheating and zeroing, and adjust each instrument to the required indication position.
5.2.4 According to the properties of the material and the experimental requirements, set the temperature conditions on the temperature program controller to put the high-temperature furnace in the manual experimental state.
5.2.5 Use the quadrupole mass spectrometer to measure the dynamic background of the system. 5.3 Determination of material degassing curve
5.3.1 Use an appropriate method to put the sample from the sample chamber into the sample chamber. The ordinary recorder records the pressure change curve in the sample chamber over time (i.e., the degassing curve). When the pressure returns to the background pressure, the experiment is over. 5.3.2 If the next sample is to be tested, the high-temperature furnace is withdrawn, and the tested sample is moved into the sample chamber. Repeat the operating steps of 5.2.4 to 5.3.1. 5.4 Degassing component analysis
In step 5.3.1, the sample is put into the sample chamber, and the quadrupole mass spectrometer scans at the same time, and the mass spectrum is recorded with a fast recorder.
6 Data processing
Determine the time-varying curve of the degassing rate6.1
According to the experimentally measured degassing curve and formula (1), calculate the time-varying degassing rate dp(t)
q()=p(t)F+$
Wherein: g(t)-degassing rate, L·Pa/sP(u) pressure, Pa;
F-known flow conductance, L/S;
t—time, S;wwW.bzxz.Net
v-volume of the sample chamber, L
6.2 Calculation of degassing volume
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In time t, the amount of gas Q(L·Pa) released by the sample is calculated according to the following formula: Q=foq(t)dt
P(t)F+ dP()
According to the properties, types, shapes, requirements, etc. of the sample, it is converted into the degassing volume per unit weight or per unit area, per unit volume, etc.
6.3 According to the image coefficients of the various gas fragment peaks of the quadrupole mass spectrometer and the relative sensitivity of various gases and the ion flow values under the corresponding mass number in the mass spectrum obtained by the test, a linear equation system is established to solve the partial pressure. 7 Test report
7.1 Curve of material degassing rate changing with time &(L.Pa /s)
Use single logarithmic coordinate paper, the ordinate (logarithmic coordinate) is the degassing rate g (L·P/s), and the abscissa is the time t(s).
7.2 Material unit degassing disk
7.3 Curve of material degassing composition changing with time Pn(Pa)
Use single logarithmic coordinate paper, the ordinate (logarithmic coordinate) is the pressure P (p), and the abscissa is the time t (s). 7.4 The test report shall indicate:
8. Material name, thickness, weight, model (or brand), manufacturer. b. Experimental temperature. If the temperature is increased at a certain rate, the heating rate and insulation value shall be given. 8 Main sources of error
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Temperature fluctuation of high temperature furnace and measurement error of thermocouple, calibration and measurement error of ultra-high vacuum gauge; stability of filament emission current. 8.2
Calibration and measurement error of quadrupole mass spectrometer, and error caused by change in degassing rate in a scanning cycle. 8.4
When the sample is degassed, the error caused by the adsorption of a certain amount of gas on the inner surface of the test system. 8.5
When the test system is exhausted and baked, the sample will not be completely at room temperature, which will have a certain impact on its gas content and calibration error of conductance.
Error caused by changes in laboratory environment (temperature, humidity, air pressure, etc.), 9 Notes
The flow conductance in the test system can be replaced according to the requirements of the sample, but it must meet F<
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