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GB/T 4937.20-2018: Semiconductor devices -- Mechanical and climatic test methods -- Part 20: Resistance of plastic encapsulated SMDs to the combined effect of moisture and soldering heat
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Semiconductor devices -- Mechanical and climatic test methods -- Part 20: Resistance of plastic encapsulated SMDs to the combined effect of moisture and soldering heat
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Basic data | Standard ID | GB/T 4937.20-2018 (GB/T4937.20-2018) | | Description (Translated English) | Semiconductor devices -- Mechanical and climatic test methods -- Part 20: Resistance of plastic encapsulated SMDs to the combined effect of moisture and soldering heat | | Sector / Industry | National Standard (Recommended) | | Classification of Chinese Standard | L40 | | Classification of International Standard | 31.080.01 | | Word Count Estimation | 22,251 | | Date of Issue | 2018-09-17 | | Date of Implementation | 2019-01-01 | | Issuing agency(ies) | State Administration for Market Regulation, China National Standardization Administration | GB/T 4937.20-2018: Semiconductor devices -- Mechanical and climatic test methods -- Part 20: Resistance of plastic encapsulated SMDs to the combined effect of moisture and soldering heat
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Semiconductor devices - Mechanical and climatic test methods - Part 20. Resistance of plastic encapsulated SMDs to the combined effect of moisture and soldering heat
ICS 31.080.01
L40
National Standards of People's Republic of China
Semiconductor device mechanical and climatic test methods
Part 20. Plastic surface mount devices are moisture resistant
And welding heat combined effects
Part 20.ResistanceofplasticencapsulatedSMDstothecombinedeffectof
(IEC 60749-20.2008, IDT)
Published on.2018-09-17
2019-01-01 implementation
State market supervision and administration
China National Standardization Administration issued
Content
Foreword III
1 Scope 1
2 Normative references 1
3 General 1
4 Test equipment and materials 1
4.1 Damp heat test chamber 1
4.2 Reflow soldering equipment 1
4.3 substrate 2
4.4 Wave soldering equipment 2
4.5 Gas reflow soldering solvent 2
4.6 Flux 2
4.7 Solder 2
5 Procedure 2
5.1 Initial test 2
5.1.1 Visual inspection 2
5.1.2 Electrical test 2
5.1.3 Acoustic scanning internal inspection 2
5.2 Drying 3
5.3 Water vapor impregnation 3
5.3.1 General requirements 3
5.3.2 SMD test conditions for non-dry packaging 3
5.3.3 Dry packaging of SMD water vapor impregnation 3
5.4 Welding heat 4
5.4.1 Overview 4
5.4.2 Heating method for infrared convection or convection reflow welding 5
5.4.3 Heating method for gas phase reflow soldering 6
5.4.4 Wave soldering heating method 6
5.5 Recovery 7
5.6 Final test 7
5.6.1 Visual inspection 7
5.6.2 Electrical Characteristics Test 7
5.6.3 Acoustic scanning inspection 7
6 Details to be specified in the relevant documents 7
Appendix A (informative) Test method description and details of the combined effects of moisture and soldering heat on plastic surface mount devices 9
A.1 Water vapor impregnation description 9
A.1.1 Water Vapor Dipping Guide 9
A.1.2 Considerations based on water vapor impregnation 9
A.2 Water vapor content measurement procedure 13
A.3 Welding heat method 14
A.3.1 Temperature profile for infrared convection and convection reflow soldering 14
A.3.2 Temperature profile of gas phase welding 16
A.3.3 Heating method for wave soldering 16
Figure 1 Sample temperature curve measurement method 2
Figure 2 Wave soldering heating 7
Figure A.1 Water vapor diffusion process at a temperature of 85 ° C and a relative humidity of 85% 10
Figure A.2 Definition of resin thickness and first layer interface 10
Figure A.3 The time required for water vapor immersion to saturation at 85 ° C as a function of resin thickness 10
Figure A.4 Correspondence between water vapor saturation and temperature in resin 11
Figure A.5 Correspondence between water vapor content and thickness in the first interface resin under different wetting conditions 11
Figure A.6 Correspondence between water vapor content and thickness in the first interface resin under method A water vapor impregnation 12
Figure A.7 Correspondence between water vapor content and thickness in the first interface resin under method B water vapor immersion conditions 13
Figure A.8 Correspondence between water vapor content and thickness in the first interface resin under the condition B2 water vapor immersion conditions
Figure A.9 Infrared convection and convection reflow soldering temperature curves for Sn-Pb eutectic soldering 14
Figure A.10 Infrared convection and convection reflow soldering temperature profiles for lead-free soldering 14
Figure A.11 Sectional curve 16
Figure A.12 Temperature profile of gas phase soldering (condition IA) 16
Figure A.13 Immersion method for immersion in the weld tank 17
Figure A.14 Correspondence between infrared convection reflow soldering and wave soldering 17
Figure A.15 SMD body temperature during wave soldering 17
Table 1 Water vapor immersion conditions of non-dry packaging SMD 3
Table 2 SMD water vapor immersion conditions for dry packaging (Method A) 3
Table 3 SMD water vapor immersion conditions for dry packaging (Method B) 4
Table 4 Sn-Pb eutectic process---reflow soldering temperature classification 5
Table 5 Lead-free process --- reflow soldering temperature classification 5
Table 6 Heating conditions for gas phase reflow soldering 6
Table 7 Infiltration conditions of wave soldering 7
Table A.1 Comparison of pre-heating water vapor immersion conditions equivalent to actual storage conditions Table 11
Table A.2 Segmentation curve 15
Foreword
GB/T 4937 "Mechanical and Climatic Test Methods for Semiconductor Devices" consists of the following components.
--- Part 1. General;
--- Part 2. Low pressure;
--- Part 3. External visual inspection;
--- Part 4. Strongly accelerated steady-state damp heat test (HAST);
---Part 5. Steady-state temperature and humidity bias life test;
---Part 6. High temperature storage;
--- Part 7. Internal water vapor content test and other residual gas analysis;
--- Part 8. Sealing;
---Part 9. Logo durability;
--- Part 10. Mechanical shock;
--- Part 11. rapid temperature change double tank method;
--- Part 12. Sweeping vibration;
--- Part 13. Salt spray;
--- Part 14. Terminal strength (lead robustness);
---Part 15. Resistance to soldering of through-hole mounting devices;
--- Part 16. Particle collision noise detection (PIND);
---Part 17. Neutron irradiation;
---Part 18. Ionizing radiation (total dose);
---Part 19. Chip shear strength;
--- Part 20. The combined effects of moisture-resistant and soldering heat on plastic surface mount devices;
---Part 20-1. Operation, packaging, marking and transport of surface mount devices sensitive to the combined effects of moisture and soldering heat;
---Part 21. Solderability;
---Part 22. Bonding strength;
--- Part 23. High temperature working life;
--- Part 24. Accelerated moisture-resistant and non-biased strong accelerated stress test (HSAT);
---Part 25. Temperature cycling;
--- Part 26. Electrostatic discharge (ESD) sensitivity test human body model (HBM);
--- Part 27. Electrostatic discharge (ESD) sensitivity test mechanical model (MM);
--- Part 28. Electrostatic discharge (ESD) sensitivity test, charged device model (CDM), device level;
---Part 29. Latch test;
--- Part 30. Pre-treatment of unsealed surface mount devices prior to reliability testing;
--- Part 31. Flammability of plastic encapsulated devices (internal);
--- Part 32. Flammability of plastic encapsulated devices (external);
---Part 33. Accelerated moisture resistance without bias high pressure cooking;
--- Part 34. Power cycling;
--- Part 35. Acoustic scanning microscopy of plastic electronic components;
---Part 36. Constant acceleration;
--- Part 37. Plate-level drop test method using accelerometers;
--- Part 38. Soft error test methods for semiconductor memory devices;
--- Part 39. Measurement of moisture diffusivity and water dissolution rate of raw materials for semiconductor components;
--- Part 40. Plate-level drop test method using tension meter;
--- Part 41. Reliability test methods for non-volatile memory devices;
--- Part 42. Storage of temperature and humidity;
--- Part 43. Guide to the reliability identification scheme for integrated circuits (ICs);
--- Part 44. Test method for neutron beam irradiation single particle effect of semiconductor devices.
This part is the 20th part of GB/T 4937.
This part is drafted in accordance with the rules given in GB/T 1.1-2009.
This part uses the translation method equivalent to IEC 60749-20.2008 "Semiconductor device mechanical and climatic test methods Part 20.
Plastic surface mount devices are resistant to moisture and solder heat.
The documents of our country that have a consistent correspondence with the international documents referenced in this part are as follows.
-- GB/T 4937.3-2012 Methods of test for mechanical and climatic methods of semiconductor devices - Part 3. External visual inspection (IEC 60749-
3.2002, IDT)
Please note that some of the contents of this document may involve patents. The issuing organization of this document is not responsible for identifying these patents.
This part was proposed by the Ministry of Industry and Information Technology of the People's Republic of China.
This part is under the jurisdiction of the National Semiconductor Device Standardization Technical Committee (SAC/TC78).
This section drafted by. China Electronics Technology Group Corporation, the thirteenth research institute, Shenzhen Institute of Standard Technology.
The main drafters of this section. Gao Jinhuan, Peng Hao, Gao Ruixin, Shen Yu, Yan Xuan, Liu Wei.
Semiconductor device mechanical and climatic test methods
Part 20. Plastic surface mount devices are moisture resistant
And welding heat combined effects
1 Scope
This part of GB/T 4937 specifies the soldering heat evaluation method for plastic-sealed surface mount semiconductor devices (SMD). The test is broken
Bad test.
2 Normative references
The following documents are indispensable for the application of this document. For dated references, only dated versions apply to this article.
Pieces. For undated references, the latest edition (including all amendments) applies to this document.
IEC 60068-2-20.2008 Environmental testing of electric and electronic products - Part 2-20. Test methods Test T.
Weldability and solder heat resistance test method (Enviralmentaltesting-Part 2-20. Tests-TestT. Testmethodsforsolder-
Abilityandresistancetosolderingheatofdeviceswithleads)
Methods of mechanical and climatic test methods for semiconductor devices - Part 3. External visual inspection (Semiconductor devices -
Mechanicalandclimatictestmethods-Part 3. Externalvisualexamination)
Methods of mechanical and climatic test methods for semiconductor devices - Part 35. Scanning acoustic microscopy
Mirror inspection (Semiconductordevices-Mechanical and climatictestmethods-Part 35. Acousticmicroscopy
Forplasticencapsulatedelectroniccomponents)
3 General
The welding heat test will increase the pressure of moisture in the SMD (which SMD absorbs during storage), causing the SMD plastic package to rupture.
And electrical performance is ineffective. This section simulates the moisture absorbed by SMD stored in a warehouse or dry packaging environment.
Evaluation of welding thermal performance.
4 Test equipment and materials
4.1 Damp heat test chamber
The damp heat test chamber shall be capable of providing a temperature and relative humidity environment as specified in 5.3.
4.2 Reflow soldering equipment
The temperature profile provided by the infrared convection and gas phase reflow equipment shall be capable of complying with the welding heat conditions specified in 5.4.2 and 5.4.3. again
The temperature setting of the flow soldering equipment should be set according to the temperature curve, which refers to the surface temperature of the sample during the welding heat test, and the measuring method
As shown in Figure 1.
Note. Adhesives or thin tapes have good thermal conductivity.
Figure 1 Sample temperature curve measurement method
4.3 substrate
Except as otherwise provided in the relevant documents, any sheet, such as glass fiber or polyimide, can be used as the substrate. Use a conventional method to solidify the sample
Set on the substrate, as shown in Figure 1. If the shape of the sample terminal is changed according to Figure 1, and the electrical parameters are abnormal, it should be selected.
Choose the assembly method that avoids the shape change of the leading end and specify it in the relevant documents.
4.4 Wave soldering equipment
Wave soldering equipment shall meet the conditions specified in 5.4.4. Generally, molten solder should be able to flow.
4.5 Solvents for gas phase reflow soldering
Full fluorocarbons should be used.
4.6 Flux
Flux consists of 25% ethanol and 75% isopropanol, as specified in the relevant documents. See IEC 60068 for details.
2-20. Provisions of Appendix B of.2008.
4.7 solder
The solder composition specified in Table 1 of IEC 60068-2-20.2008 is used.
5 procedures
5.1 Initial test
5.1.1 Visual inspection
Before the test, the visual inspection shall be carried out under a 40-fold microscope in accordance with the provisions of IEC 60749-3, and special attention shall be paid to the cracks on the outer surface.
Drum kit.
5.1.2 Electrical test
Electrical performance tests shall be performed when required by relevant documents.
5.1.3 Acoustic scanning internal inspection
Unless otherwise specified in the relevant documents, the internal cracks of the sample are examined using an acoustic scanning microscope in accordance with IEC 60749-35.
Layered.
5.2 Drying
Samples shall be baked at 125 ° C ± 5 ° C for at least 24 h, unless otherwise specified in the relevant documentation.
5.3 Water vapor impregnation
5.3.1 General requirements
Unless otherwise specified in the relevant documents, the conditions of water vapor impregnation should be selected according to the packaging method of the sample (see A.1.1). If related text
The sample is specified to be baked before welding, and the sample is directly baked without water vapor impregnation.
5.3.2 SMD test conditions for non-dry packaging
The water vapor impregnation conditions shall be selected from Table 1 in accordance with the actual allowable limit storage conditions (see A.1.2.1).
Table 1 Water vapor immersion conditions of non-dry packaging SMD
condition
temperature
Relative humidity
duration
Actual allowable limit storage
A1 or B1 85±2 85±5 168±24 < 30°C, 85% RH
Note. Conditions A1 and B1 are SMD water vapor impregnation conditions for non-dry packaging in Method A or Method B.
5.3.3 Dry packaging of SMD water vapor impregnation
5.3.3.1 General requirements
The SMD water vapor immersion conditions of the dry package are shown in Table 2 or Table 3. Dry-packed SMD water vapor impregnation involves two steps. step one
Is to simulate the wet condition of SMD before opening the dry packaging or drying the locker; the second step is to simulate the SMD to open the package to the welding period.
Wet conditions. The SMD water vapor impregnation conditions for dry packaging should be selected from Method A or Method B. When the contractor specifies the SMD drying package
When the relative humidity in the installed or dried locker is between 10% and 30%, select Method A and select Method B when the relative humidity is less than 10%.
5.3.3.2 Method A
Except as otherwise provided in the relevant documents, the first step of condition A2 in Table 2 shall be carried out first, and then the table shall be carried out within 4 hours after the completion of step one.
Step 2 of Condition A2 in 2 (see A.1.2.2).
The relative humidity condition of step one should be consistent with the upper limit of the relative humidity in the moisture barrier bag. The relative humidity of step 2 should be related to the life of the workshop.
The pieces are consistent.
Water vapor immersion conditions other than moisture storage bag storage and workshop life are specified in Table 2, and other test conditions need to be relevant.
As stated in the document.
Table 2 SMD water vapor immersion conditions for dry packaging (Method A)
Conditional water vapor impregnation conditions
Dry packaging and drying lockers
Allowable storage conditions
Workshop life conditions
A2 step one condition
(85±2) °C, (30±5)% RH
168 24-0h
30 ° C, 30% RH, 1 year -
A2 step two conditions
(30±2) °C, (70±5)% RH
168 24-0h
- < 30°C, 70% RH, 168h
Note 1. Step 1 characterizes the storage conditions in SMD dry packaging or dry lockers, and also identifies the repackage caused by the distributor or user after inspection.
Storage conditions for increased relative humidity in dry packaging. When condition A2 is selected, the SMD is packaged in a moisture-proof bag with an IC reel and a desiccant.
Dry for a few weeks. The moisture barrier bag may be temporarily opened several times (once for a few hours). When the humidity indicator card in the dry package shows that the humidity is lower than
At 30%, SMD will return to its initial moisture absorption state after a few days of repackaging, allowing repackaging and inspection of SMD. under these circumstances,
It is considered that the moisture in the dry package is controlled, and it is not necessary to measure the water vapor content of the SMD (see A.2). For humidity control, humidity indication is required
Card correction.
Note 2. SMDs stored in dry packaging or dry lockers will gradually reach water vapor saturation after long-term storage, so when step 1
The water vapor immersion did not reach saturation, and the infiltration time was extended to 336 h. When the water vapor immersion in step one has reached saturation, the infiltration time is shortened.
5.3.3.3 Method B
The conditions for water vapor impregnation shall be selected from Table 3 and shall be consistent with the workshop life conditions specified in the relevant documents (see A.1.2.3).
Table 3 SMD water vapor immersion conditions for dry packaging (Method B)
Conditional water vapor impregnation conditions
From baking to dry packaging and drying
Packaging conditions for short opening
Workshop life conditions
B2
(85±2) °C, (60±5)% RH,
168 24-24h
< 30 ° C, 60% RH, 24 h < 30 ° C, 60% RH, 1 year
B2a
(30±2) °C, (60±5)% RH,
696 24-24h
< 30 ° C, 60% RH, 24 h < 30 ° C, 60% RH, 28d
B3
(30±2) °C, (60±5)% RH,
192 24-0h
< 30°C, 60% RH, 24h < 30°C, 60% RH, 168h
B4
(30±2) °C, (60±5)% RH,
96 24-0h
< 30 ° C, 60% RH, 24 h < 30 ° C, 60% RH, 72 h
B5
(30±2) °C, (60±5)% RH,
72 24-0h
< 30 ° C, 60% RH, 24 h < 30 ° C, 60% RH, 48 h
B5a
(30±2) °C, (60±5)% RH,
48 24-0h
< 30 ° C, 60% RH, 24 h < 30 ° C, 60% RH, 24 h
B6
(30±2) °C, (60±5)% RH,
6 24-0h
- < 30°C, 60% RH, 6h
Note 1. The water vapor immersion conditions of conditions B2 to B6 cover the conditions of Step 1 (30 ° C, 60% RH, 24 h) and the conditions of Step 2 (Workshop life).
Note 2. The relative humidity in the dry package exceeds 10% due to the moisture released by the wetted material and the degraded desiccant. Therefore, in SMD dry packaging
Items, IC reels, and other materials are thoroughly dried before being packaged in a moisture barrier bag. Relative humidity in dry packaging through humidity indicator card and SMD water
The steam content measurement is calibrated, see A.2.
Note 3. Because very low relative humidity cannot be obtained in dry lockers, it is not recommended to store SMD in a drying cabinet instead of a dry package.
Note 4. Condition B covers the entire SMD storage process from baking to soldering, including SMD from baking to packaging into dry packaging and dry packaging
Temporary opening and shelf life of the entire room temperature storage duration.
5.4 Welding heat
5.4.1 Overview
Unless otherwise specified in the relevant documents, the sample shall be subjected to a welding heat test within 4 hours after the completion of the water vapor impregnation or high temperature baking test.
According to the requirements of the relevant documents, the test methods and conditions for welding heat are selected from 5.4.2 to 5.4.4. No matter which test method you choose, soldering
The number of hot cycles is at least 1 time and up to 3 times. Except as otherwise provided in the relevant documents, the number of cycles of welding heat is one. If the number of cycles
More than 1 time, after the completion of one test, the temperature of the sample should be reduced to below 50 °C before the next test.
Note. If the sample is stored at room temperature for more than 4 hours without being affected by water vapor impregnation or baking, the storage time of more than 4 hours after water vapor impregnation or baking can be completed.
It is clearly stated in the relevant documents.
5.4.2 Heating method for infrared convection or convection reflow welding
5.4.2.1 Preparation
The sample is placed on a substrate.
5.4.2.2 Preheating
Except as otherwise provided in the relevant documents, the sample shall be placed in the reflow soldering equipment and preheated for 60 s in accordance with the temperature conditions specified in A.3.1.
120s.
5.4.2.3 Welding heat
After preheating, the temperature of the sample should first be raised to the peak temperature and then lowered to room temperature. According to the actual welding conditions, from Table 4 or Table 5
Select the heating conditions, which should be consistent with the relevant documents. See A.3.1 for temperature and time tolerances.
Note 1. In Tables 4 and 5, the test conditions of A are used for the temperature curve with a short actual welding time, and B is used for the temperature curve with a long actual welding time.
Note 2. After preheating, the sample temperature meets the requirements in Figure A.9, Figure A.10 or Table A.2.
Note 3. According to the context, the methods A and B in Table 4 and Table 5 and in the infrared convection reflow soldering are more suitable for condition IA and condition IB.
Table 4 Sn-Pb eutectic process---reflow soldering temperature classification
Package thickness
Mm
condition
Specified welding temperature
Test time
Corresponding volume temperature
< 350mm3 350mm3~2000mm3 ≥2000mm3
< 2.5
A 10 240°C 240°C 225°C
B 20 240°C 225°C 225°C
≥2.5
A 10 240°C 240°C 225°C
B 20 225°C 225°C 225°C
Table 5 Lead-free process---Reflow soldering temperature classification
Package thickness
Mm
condition
Specified welding temperature
Test time
Corresponding volume temperature
< 350mm3 350mm3~2000mm3 >2000mm3
< 1.6
260°C 260°C 260°C
1.6~2.5
260°C 250°C 245°C
>2.5
250°C 245°C 245°C
5.4.3 Heating method for gas phase reflow soldering
5.4.3.1 Preparation
The sample should be mounted on a substrate.
5.4.3.2 Preheating
Unless otherwise specified in the relevant documents, the sample shall be placed in a gas phase reflow soldering apparatus and preheated for 60 s at a temperature of 100 ° C to 160 ° C.
120s.
5.4.3.3 Welding heat
After preheating, the temperature of the sample rises. When the sample temperature reaches 215 °C ± 5 °C, keep 40s ± 4s according to Table 6,
See A.3.2.
Table 6 Heating conditions for gas phase reflow soldering
condition
temperature
time
II-A 215±5 40±4
5.4.4 Wave soldering heating method
5.4.4.1 Preparation
The bottom surface of the sample is mounted on the substrate using an adhesive as specified in the relevant documentation. In addition to the relevant documents, in the sample and base
Do not use flux between the plates.
Note 1. If flux is used, vaporization of the solvent in the flux will affect the temperature rise of the sample. The flux cannot coat the body of the sample and is coated as much as possible
Pin and away from the sample body.
Note 2. If the pitch (the difference between the height of the bottom surface of the SMD body and the bottom surface of the lead) is less than 0.5 mm (the thickness of the SMD body is exceeded by using a heat sink to reduce the thermal resistance)
When the 2.0mm is excluded, it shall be tested by the welding heat test in A or B. When the thickness of the SMD body exceeds 3.0 mm, the welding heat in B is used.
Test conditions test. For SMD, the test conditions for A and B are more severe than the conditions for wave soldering III-A and III-B (refer to A.3.3).
Thus, conditions III-A and III-B are generally not employed.
5.4.4.2 Preheating
Except as otherwise provided in the relevant documents, the sample shall be placed in the welding equipment and preheated at 80 ° C ~ 140 ° C for 30 s ~ 60 s.
5.4.4.3 Welding heat
After preheating, the sample and substrate are immersed together in molten solder as shown in FIG. The infiltration conditions were selected from Table 7.
a) Infiltration begins b) End of infiltration
Figure 2 Wave soldering heating
Table 7 Wetting conditions of wave soldering
condition
Welding temperature
Infiltration time
Actual welding method
III-A 260±5 5±1 single peak
III-B 260±5 10±1 doublet
5.4.4.4 Cleaning
If flux is used, it should be removed according to the cleaning method specified in the relevant documents.
5.5 Recovery
If the recovery conditions are specified in the relevant documents, the samples shall be stored under standard atmospheric conditions for a specified period of time as required by the documentation.
Note. Wave soldering is not the welding method commonly used by the contractor. If the contractor does not have this equipment, the corresponding welding heat method is between the contractor and the user.
Provisions are made in the agreement between the two.
5.6 Final inspection
5.6.1 Visual inspection
After the test is completed, visual inspection is carried out under a 40-fold microscope in accordance with IEC 60749-3, and the cracks on the outer surface...
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