This standard lists the test methods applicable to semiconductor devices (discrete devices and integrated circuits). You can choose from them when using. For non-cavity devices, additional test methods may be required. GB/T 4937-1995 Mechanical and climatic test methods for semiconductor devices GB/T4937-1995 Standard download decompression password: www.bzxz.net

GB/T4937—1995
This standard is revised according to the amendments to GB4937—85 issued by the Electric Engineering Committee IEC749:1984 (Mechanical and climatic test methods for semiconductor devices), IEC749:1991-11 and IEC749:1993-09. The revised standard is equivalent to the IEC 749 standard. The content of this standard is relatively large, so a subtitle is added in front of the standard text for easy reference. The chapters, clauses, figure numbers and tables in this standard are equivalent to those of the IEC standard, so as to be in line with international standards. This standard is issued by the Ministry of Electronics Industry of the People's Republic of China. This standard is under the jurisdiction of the National Technical Committee for Standardization of Semiconductor Devices. The drafting units of this standard are: Shangyou Electronic Instrument Standard and Measurement Testing Institute, China Electronics Technology Standardization Institute. The main drafters of this standard are: Shuo Yueqin and Wang Changfu. GB/T 4937- 1995
IEC former
IEC749:1991 amendment was prepared by TECTC47 Semiconductor Device Technical Committee and TC47A Jicheng Circuit Branch. The text of this amendment is based on the following documents: June Law
47(C031054
47(C031084
47/47A(C0)
1169/224|| tt||47(C0)1170
47(C0)1186
Voting Report
47(C0)1135
47(C0)1175
47/47A(C0)
1289/201
47(C0)12B3
47(C0)1272
February Law
4 7(C0)1182
Voting Report
47(CO)1218
All voting materials approved by this amendment can be found in the voting reports listed in the table above. IEC749:1993 Amendment IF: Prepared by TC47. Semiconductor Devices Technical Committee. Delete
47(CO)1252
47(C0)1314
47(C0)1316
Voting Report
17(60)1333
47(CO)1343
47(C0)1348
All voting materials approved by this amendment can be found in the voting reports listed in the table above. 1 Scope and Purpose
National Standard of the People's Republic of China
Mechanical and Climatic Test Methods for Semiconductor Devices and climatic
test methods for semiconductor devicesPart 1 General
GE/T 4937—1995
idt IEC 749:1984
Replaces GB4937—86
This standard lists the test methods applicable to semiconductor devices (discrete devices and integrated circuits). You can choose from them when using. For non-cavity devices, additional test methods may be required. Note: Non-cavity devices refer to devices in which the packaging material is in close contact with all exposed surfaces of the die without any space in the device structure. This standard has taken into account IEC 68≤Basic Environmental Test Procedures as much as possible. 2 Purpose
To determine the unified preferred test methods and preferred values ​​of stress levels in order to evaluate the environmental performance of semiconductor devices. If this standard conflicts with relevant specifications, the relevant specifications shall prevail. 3 Terms, definitions and text symbols
Reference the following standards;
GB2421-89 Basic Environmental Test Procedures for Electrical and Electronic Products General Rules GK2423 Basic Environmental Test Procedures for Electrical and Electronic Products Test Methods GB2424 Basic Environmental Test Procedures for Electrical and Electronic Products Guide GB5169.5-82 Fire Hazard Tests for Electrical and Electronic Products Needle Flame Test Methods IEC747 Semiconductor Devices Discrete Devices and Integrated Circuits IEC748 Semiconductor Devices Integrated Circuits
4 Standard atmospheric conditions
Reference: GB2421 General Rules for Basic Environmental Testing Procedures for Electrical and Electronic Products; Unless otherwise specified, all tests and recovery should be carried out under the standard atmospheric conditions specified in 5.3 and 5.4 of GB2421-89. The conditions are:
Temperature: 15℃～35℃bzxZ.net
Relative humidity: 45%～75% (when applicable); Air pressure: 86 kPa~j06 kPa (860 mbar~1 060 mbar). All electrical measurements and recovery before measurement should be carried out under the following atmospheric conditions Temperature: 25℃±5℃
Approved by the State Administration of Technical Supervision on December 22, 1995 and implemented on August 1, 1996
GB/T 4937--1995
Relative humidity: 45%~75% (when applicable)1
Air pressure: 86kPa~106kPa<860mbar-1060mbar). The benchmark test shall be carried out under the following standard atmospheric conditions: temperature: 25℃±1℃
Relative humidity: 48%~52%,
Air pressure, 86 kPa-~106 kPa (860 mbar~~1 060 tmbar), before measurement, the sample shall be stored until the temperature is balanced. The ambient temperature during the measurement shall be stated in the test report. During the measurement, the sample shall not be subject to airflow, light or other influences that may cause errors. 5 Appearance inspection and dimensional inspection
5.1 Appearance inspection
5.1. 1 Purpose
To verify that the physical properties of the material, the design, structure, marking and process of the device are consistent with the requirements of the applicable detailed specifications. 5. 1.2 Pressure
This test is applicable to the device manufacturer's factory inspection or the user's factory inspection. The additional requirements for the optical system of the optoelectronic device must be stated where applicable.
5.1.3 Definition
Defect, a pit caused by unintentional damage in the encapsulating material. 5.1.4 Test Equipment
The equipment used in this test should be able to confirm whether the device meets the requirements. The equipment can magnify 3 to 10 times and has a considerable field of view. For example: a circular magnifying glass with lighting.
5.1.5 Test Method
The device should be inspected under the condition that the entire device can be seen under the magnification of 3 to 10 times (unless otherwise specified) according to the applicable specifications and the criteria listed in 5.1.6. If it is suspected that foreign matter is attached to the device, it can be treated with clean filtered air (exhaust or blow) with a maximum flow rate of 27m/s (if the device is sensitive to static electricity, ionized air should be used). 5.1.6 Failure Criteria
If the device has any of the following conditions, it shall be judged as unqualified. 5.1.6-7 The device model, terminal identification, marking (content, position and clarity), material, structure and process do not meet the applicable specification requirements.
5-1.6.2 Defects or damage caused by manufacturing, operation or testing; a) Damage, pits or cracks in the package. Cracks, scratches, gaps and bubbles on the surface of the package shall not constitute failure unless these defects affect the performance of the package or violate other criteria of this method such as marking, coating, etc. b) There are defects on the surface with a linear width greater than 1.5mm or a depth greater than 0.2mm. Unless otherwise specified, such as for ultra-small packages. e) The defect exposes the sealing glass (this part is not exposed before the defect) or internal materials that should not be exposed by design (such as lead frames or conductive layers).
5.1.6.3 Visible signs of corrosion, contamination or damage, broken leads, broken seals (except glass meniscus), peeling of plating, blistering, etc. Discoloration of the plating shall not constitute a failure unless there are signs of peeling, pinholes or corrosion. More stringent requirements may be specified in the relevant specifications for very small packages.
5.1.6.4 Leads are misaligned or changed from their normal position, or there are sharp or unspecified bends in the leads. Ribbon leads are distorted from the normal lead plane.
5.1.6.5 Extraneous material such as varnish or other adhesive is present on the leads. 5.1.7 Contents to be given in the relevant specifications
The following details are specified in the applicable documents: CB/T 4937--1995
a) Marking and terminal or pin identification requirements (see 5.1.6.1); b) Detailed appearance requirements are specified on the drawing: c) Defect dimensions, if different from the provisions of 5.1.6.2b). 5.2 Dimension inspection
The dimensions given in the relevant specifications must be inspected. 6 Electrical measurements
6.1 For environmental testing, the characteristics to be inspected should be selected from the "Acceptance and Reliability" chapters of IEC747 or IEC:748. The characteristics to be inspected by the factory are specified for each device category. 6.2 Measurement conditions: See the "Pre-durability test conditions" table in the "Acceptance and reliability" chapter of IEC747 or IEC748. 6.3 Initial measurement
If only the upper limit criterion and (or) the lower limit criterion of the specification are required, the manufacturer can decide whether to perform initial measurements. When the individual values ​​of each device are used as criteria, initial measurements should be deleted. 6.4 Monitoring during environmental testing
Only specified when applicable.
6.5 Final measurement
When the relevant specifications require a test to be part of a group of tests (groups), measurements are only required at the end of the group of tests. For some tests, such as solderability or lead fatigue, devices with unqualified electrical parameters can be used. Chapter 1 Mechanical test methods
Select the appropriate test method based on the device type and packaging form. The relevant specifications should specify which tests are appropriate. 1 Strength of lead terminals
Quote GB2423.29-82 Basic environmental test procedures for electric and electronic products Test U: Strength of lead terminals and integral mounting parts 1.1 Pull square
This test shall be in accordance with the provisions of test UI {1, and its special requirements are as follows; in Article 2.6, change to:
After the test, magnify 3 to 10 times for inspection. If there is any breakage (except for the sealing meniscus), looseness, or relative movement between the lead (or lead-out) and the device body, the device shall be rejected.
1.2 Bending
This test shall be in accordance with the provisions of test Ub, with the following special requirements: In the case of dual-row direct-connect package or similar package structure, it is difficult or impractical to use method 1 for the test, only 4.2, method 2 is recommended for this tube body package structure. 1.3 Torque
This test shall be in accordance with the provisions of test Uc, with the following special requirements: Method
Method A (severity 2) or method B shall be used. Failure criterion
When the stress is removed and the device is magnified 10 to 20 times for inspection, any break (except the sealing meniscus), looseness or root movement between the lead terminal and the device body shall be regarded as a device failure. 1.4 Torque
1.4.1 Torque test of bolts
CB/T4937—1995
This test shall be in accordance with the provisions of test Ud, with the following special requirements. If the device shows any of the following conditions, the device shall be considered to have failed: the bolt is broken or elongated more than 1/2 of the torque; there is evidence of thread wear or deformation of the tube seat; the device fails to pass the electrical measurement after the test (if applicable) 1.4.2 Torque test of lead wires - new test (Ud2) 1.4.2.1 month
Determine the ability of the lead terminal to withstand the external torque after the device is assembled, during inspection or maintenance. 1.4.2.2 Test method
The device should be firmly fixed and the torque or torsion should be slowly applied to the lead terminal under test until the torsion angle reaches 30°±10° or the specified torque is reached, whichever condition occurs first. Then a torque of 1.4×102N.m and 1.4×10-3N.m is applied to the lead terminal 3.0mm±0.5mm from the tube body, or within 1 mm from the end of the lead terminal (if the lead terminal is less than 3mm), so that the lead terminal returns to its original position. Torque shall be applied in each direction.
When the device has a lead-out terminal formed with a body, torque may be applied at 3.0 + 0.5 mm from the root of the lead-out terminal. 1.4.2.3 Final measurement
After the test, magnify it 3 to 10 times for inspection. If the lead-out terminal shows any signs of breakage, looseness or relative movement between the lead-out terminal and the body, the device shall be rejected. 1.4.2.4 Contents to be given in the relevant specifications Selection and number of test leads.
2 Soldering
Reference: GB2423.2882 Basic environmental test procedures for electrical products Test T: Soldering test method 2.1 Solderability
This test shall be carried out in accordance with the provisions of Test Ta, and its special requirements are as follows: When method 1 is selected;
The lead-out terminal is subjected to soldering. The lead-out terminal is not in the slot to within 1.5 mm from the bottom plane of the device or immersed to other distances specified in the relevant specifications.
Note: When the length of the lead is less than 1.5mm from the bottom plane of the device, other failure judgments can be used and should be specified. "When force method 2 is selected:
The lead-out terminal is subjected to the molten iron welding method with a No. A soldering iron tip. The distance between the molten iron welding point and the device body should be in accordance with the relevant specifications, and the soldering time should be 3.5 s±0.5 5. When method 3 is selected:
The lead terminals are subjected to the solder ball method. Each lead terminal is tested at point 1 1mm above 5mm from the device body. The lead should be stained with solder within 2.5s.
Criteria for good wetting:
When observed at a magnification of 10 times, the wetted surface should be covered with a smooth and shiny solder coating, and its scattered defects, such as pinholes or traces of unwetted area, should not exceed 5%. These defects should not be concentrated in the place. Aging:
When accelerated aging is required in the relevant regulations, "Aging 16" is used first. Aging 3 can be used, and aging 1a and 2 are not used. Dewetting: (according to test Ta clause 4.9)
Unless required by the relevant regulations, the test is not mandatory. 2.2 Resistance to soldering heat
GB/T 4937—1995
This test shall be carried out in accordance with the provisions of test Tb. The special requirements are as follows: Method
Method 1A with an immersion time of 10 to 1s or Method 1B shall be used. 2.3 Plastic encapsulated surface mount devices (SMD) shall be resistant to the combined effects of moisture and soldering heat. 2. 3. January
This section provides a test method for evaluating the resistance of plastic encapsulated surface mount devices (SMDs) to soldering heat. This test is destructive. 2.3.2 General Description
The moisture pressure generated by soldering heat (moisture absorbed during storage) can cause cracks in the plastic package of plastic encapsulated surface mount devices (SMDs) and electrical performance failure. These problems need to be evaluated. In this method, the SMD is immersed in a humid environment to evaluate the heat resistance of the device. This environment simulates the moisture absorbed by the device when stored in a warehouse or dry packaging box. 2.3.3 Test Equipment and Materials
a) Humidity Chamber
The humidity chamber should be able to provide a test in accordance with 2.3-4 c) The environment with the temperature and relative humidity specified in the above. b) Reflow soldering equipment
The vapor phase soldering equipment and the infrared reflow soldering equipment can provide the soldering heat temperature distribution diagram specified in 2.3.4d)1) and d)2). During the soldering heat process, the temperature distribution of the package surface is measured as shown in Figure 3 to adjust the reflow soldering equipment. Adhesive
Introduction
Note; The adhesive must have good conductivity. Resin
Figure 3 Temperature distribution measurement method of sample||tt ||e) Base
Thermoelectric bias
Unless otherwise specified in the relevant specifications, plates such as aluminum, epoxy, glass fiber, polyimide or metal mesh can be used as the base. The sample is mounted on the position bone shown in Figure 3 by ordinary methods. d) Solder bath
The soldering heat conditions given in 2.3.4#:) are followed. e) Solder for vapor phase welding
Perfluoroisobutylene should be used.
f) Flux
Unless otherwise specified in the relevant specifications, it shall be in accordance with the provisions in Appendix C of GB 2423. 28--82. The flux contains 25% by weight of rosin and 75% by weight of isopropyl alcohol.
g) Baking material
The composition of the solder shall be in accordance with the provisions in Appendix B of GB2423.28--82. 2.3.4 Procedures
a) Initial test
1) Appearance inspection
Appearance inspection shall be in accordance with the provisions of Chapter 5, Part 1 of this standard. 2) Electrical performance test
Electrical test shall be carried out in accordance with the requirements of relevant specifications.
b) Pretreatment
GB/T 4937—1995
The sample shall be baked at the highest rated temperature of 125℃±5℃ or lower than this temperature. Note: If the temperature is lower than 125℃, pretreatment for more than 6h is required. C Moisture penetration
According to 2.3.6.1 The moisture immersion temperature is required to be 85℃±2℃, and the relative immersion temperature and immersion time are selected from the following table. Method
Relative immersion temperature
Immersion time
168±24
168±24
d) Welding heat
Unless otherwise specified in the relevant specifications, the sample shall be subjected to the welding heat test within 24h after the end of the moisture immersion. According to the relevant specifications, select the welding heat test method and conditions from d)1)~d)3) of this clause. No matter which method is selected, it should consist of one cycle. 1) Vapor phase welding heating method
1) Preparation
The sample is installed on the base
ii) Preheating
Unless otherwise specified, the sample should be preheated in the vapor phase welding device at a temperature of 150℃±10 for 1min~2min. i) Soldering heat
After preheating, the sample temperature should rise. When the sample temperature rises to 215℃±5℃, it should be kept at constant temperature for 40s±3s (see 2.3.8.1).
2) Infrared reflow soldering heating method
The sample is installed on the base.
) Preheating
Unless otherwise specified, the sample should be preheated at 150℃±10℃ in an infrared heating reflow soldering device for 1 min to 2 min. ) Soldering heat
After preheating, the sample temperature should rise to a maximum of 240℃, and then drop to room temperature (see 2.3.8.2). After preheating, the sample temperature should be as given in Figure 11 of 2.3.8.2. 3) Soldering tank heating method
i) Immerse in flux
Immerse the lead end of the sample in flux towel under room temperature. ii) Cleaning of solder surface
Use a stainless steel scraper or equivalent tool to scrape the surface of the molten solder. ili) Immersion in solder bath
Unless otherwise specified in the relevant specifications, the sample should be immersed in the molten solder as shown in Figure 4, with a depth of 10mm±5mm and an immersion and withdrawal speed of 25mm/s±2.5mm/s. According to the actual situation of the welding process, select the temperature and immersion time from the table below. iv) Removal of residual flux
After immersion in soldering, the residual flux should be removed.
e) Recovery
Depth t10mm±5tim
GB/T 4937--1995
ITTTTTTT
Figure 4 Immersion method
Solder temperature
245±5
260±5
260±5
Immersion time
If recovery is required in the relevant specifications, the sample should be recovered under standard atmospheric conditions, and the recovery time shall be in accordance with the specifications. () Final test
1) Appearance inspection
Chapter 5, Part 1 of this standard stipulates that an appearance inspection should be carried out after the test. 2) Electrical performance test
Electrical performance test should be carried out as specified in the relevant specifications. 2.3-5 Contents to be given in the relevant specifications
a) Base material
b) Composition of flux
c) Failure criteria
d) Pretreatment
e) Moisture immersion
f) Method and conditions of soldering heat
g) Depth and speed of immersion and withdrawal
: h) Recovery conditions
2.3.6 Description of moisture immersion
2.3.6.1 Guidelines for moisture immersion
2.3.4a) and f)
2.3.4d)
2.3.4d)
2.3.4e)
2.3.4c) Methods A and B given in the table are used for identification tests of SMD devices, while Method C is not used for identification tests of SMD devices. It is used as an acceptance test. Method A is applicable to dry-packaged SMD devices, while method B is applicable to non-dry-packaged SMD devices stored under standard atmospheric conditions.
When encapsulation cracking occurs due to soldering heat after moisture immersion under method B, it is recommended that the device be dry-packaged or stored in a dry atmosphere.
If encapsulation cracking occurs due to soldering heat after moisture immersion under method A, it is recommended that the device be pre-dried before soldering to the PCBL.
GB/T 4937—1995
2.3.6.2 Consideration of moisture immersion conditions is based on the fact that moisture in the encapsulation is generated by the diffusion of water into the resin. Since encapsulation cracking occurs from the die pad or near the die during the soldering process, it is necessary to measure the moisture content of the resin. An example of moisture immersion at a temperature of 85 and a relative humidity of 85% is shown in Figure 5. Figure 5 shows that if the resin thickness from the back of the package to the die solder tab is 1 mm, saturation will take 168 hours. To simulate the dry packaging or warehouse storage of the device for 3 to 4 months, the soldering heat test must reach saturation, and the diffusion rate of water vapor into the resin depends only on the temperature. Knowing the resin thickness defined in Figure 6, the relationship between the saturation time of moisture and the resin thickness at 85°C is shown in Figure 7. Figure 7 shows that for the general SMJ) device resin thickness of 0.5mm to 1.3mm, the moisture required immersion time is 168h. As shown in Figure 8, the saturated moisture content in the resin depends on the relationship between temperature and relative humidity. Figure 8 can be used to determine the relative humidity required for moisture immersion, so that the moisture content at 85°C can correspond to the moisture content at air temperature, as shown in Table II. Figure 8 is used to determine the moisture immersion conditions for the soldering heat test.
Figure 9 shows the moisture content of the resin near the die or die solder pad under moisture immersion and under actual storage conditions. Table [Comparison method of actual storage conditions and equivalent moisture immersion conditions before soldering heat test
Tree moisture content
(ng /ent)
Actual storage conditions
Typical temperature 25 Relative humidity (20110)%Typical temperature 25℃Relative humidity (60±15)%Storage time
Back surface of SMT
Distance from back surface of SML (mm)
Chip base
Figure 5 The process of moisture diffusion at 85℃, 85%RHRelative humidity of moisture diffusion at 85%
Chip base/
Note: The thicker one of α or b depends on the thickness of resinFigure 6 Determination of resin thickness
Time required for the center of the package to reach 95%
Resin thickness (mm)
GB/T 4937
resin saturated
moisture content
(aig/cma:
Figure 785C moisture penetration time and resin thickness as a function of 86,65%RH,168 h
moisture after the core or
tube core solder pad near the tree
moisture maximum
25C,75%RH.2 100 h
85℃,30%RH,168h
85℃,30%RH,2000h(+drying packaging）
Saturated moisture content of resin
(mR/cm\)
25℃ potential: storage conditions
Method B
Method A
Composition data (core)
85℃ equivalent conditions
Relationship diagram B between temperature and saturated moisture content of resin
85'C:,R5%RH.24 h
Resin thickness (mm)
Figure 9 Relationship between moisture content in resin near die pad or die and resin thickness under several conditions 1.5
The moisture content of the device (MCD) is often used to indicate the moisture content of SMD. However, the measurement of MCD should be used with caution for the following reasons:
If the MCD is stable, the device surface contains a lot of moisture and the inside is dry due to different storage conditions of the device, and vice versa.
If the resin moisture content is stable, the MCD varies according to the proportion of resin in the device. 2.3.7 Moisture content determination procedure
Measurement procedure for moisture content of devices such as SMD: The devices are weighed accurately to 0.1 tmg (= z) per device. According to the absolute maximum rating of the storage temperature allowed in the relevant specifications, the devices are dried at 150℃ for 24 h or 125℃ for 48 h.
GB/T 4937—1995
Allow the device to cool to room temperature within 30 min±10 min. The device is reweighed (=y)
The moisture content (=MCD) of the device is calculated by the following equation: MCD=100_(ry)/yJ%
2.3.8 Temperature distribution diagram of reflow soldering heat
2.3.8.1 Temperature distribution diagram of vapor phase soldering
The device soldering test shall be carried out according to the temperature distribution diagram shown in Figure 10. 2.3.8.2 Temperature distribution of infrared reflow soldering The soldering test of devices using infrared reflow soldering should be carried out according to the temperature distribution diagram shown in Figure 11. Illumination
2155℃
100100
40s±3
Figure 10 Temperature distribution diagram of vapor phase welding
3 Sinusoidal vibration
240c max-
235℃±5℃
150℃±10℃
1.10m±10
Figure 11 Temperature distribution diagram of infrared reflow soldering Reference: GB/T2423.10—1995 Environmental testing for electric and electronic products Part 2: Test methods Test Fc and guidelines: Vibration (normal zeta)
This test shall be in accordance with the provisions of Test Fc, and its special requirements are as follows: The leads and tube body of the tested device shall be firmly fixed: Scanning duration;
Acceleration: 196 m/s (20 g);
-.Frequency range: 100 Hz.～2 000Hz, one cycle number for each axis; 15.
4 Shock
Reference: GB/T2423.5—1995 Environmental testing for electric and electronic products Part 2 Test methods Test Ea and guidance: Shock This test shall be in accordance with the provisions of Test Ea, and its special requirements are as follows: The appropriate conditions shall be selected from the following table, and the mass and internal structure of the device shall be taken into account when selecting. Peak acceleration amplitude
14 700 m/(1 500 g)
4 900 m/ga(500 g)
980m/g(100g):
Duration
Half-sine wave
Half-sine wave
Half-sine wave
The device shall withstand three consecutive shocks in both directions of two mutually perpendicular axes, that is, the total number of shocks is 18 times, and the selection of the perpendicular axis should enable the failure to be fully exposed.
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