This specification specifies the identification and performance requirements for conformal coating compounds applied by dipping, brushing, spraying or vacuum deposition for printed board assemblies. This specification applies to rigid printed board assemblies. SJ 20671-1998 Electrical insulating compounds for coating printed board assemblies SJ20671-1998 Standard download decompression password: www.bzxz.net

Military Standard of the Electronic Industry of the People's Republic of China FL5999
SJ 20671 — 1998
Insulating compound, electricalfor coating printed circuit assembliesPublished on March 11, 1998
Implementation on May 1, 1998
Approved by the Ministry of Electronics Industry of the People's Republic of China 1 Scope
1.1 Subject content
1.2 Scope of application
1.3 Classification
2 Reference documents
3 Requirements
3.1 Qualification
3.2 Materials
3.3 Compatibility
3.4 ​​Curing time and temperature
3.5 Appearance
3.6 Coating thickness of test specimen
3.7 Mildew resistance
3.9 Insulation resistance
3.10 Dielectric withstand voltage
3.11 Q value (resonance)
Temperature shock
Moisture resistance·
3. 14 Flexibility
3.15 Hygrothermal aging
3.16 Flame retardancy
4 Quality assurance regulations
4.1 Inspection responsibility
4.2 Inspection classification
4.3 Material inspection
4.4 Inspection conditions
4.5 Identification inspection
4.6 Quality consistency inspection
4.7 Preparation of test samples
4.8 Test methods
5 Delivery preparation
5.1 Packaging container
5.2 Marking…·
+（3)
.. (5)
：(8)
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6 Notes
6.1 Intended use
6.2 Contents of ordering documents,
6.3 Precautions
6.4 Ventilation...
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People's Republic of China Electronic Industry Military Standard Insulating compound, electricalfor coating printed circuit assemblies 1 Scope
SI 20671—1998
1.1 Subject matter
This specification specifies the identification and performance requirements for conformal coating compounds for printed circuit assemblies applied by dipping, brushing, spraying or vacuum deposition. 1.2 Scope
This specification applies to rigid printed board assemblies. 1.3 Classification
The types of conformal coatings are specified as follows (see 6.1 and 6.2):AR type - acrylic resin;
ER type - modified epoxy resin;
SR type - silicone resin;
UR type - polyurethane resin;
XY type - paraxylene.
2 Referenced documentsbzxz.net
The valid versions of the following documents constitute a part of this specification within the scope of this specification. When there is a conflict between the main text of this specification and the referenced documents, the provisions of this specification shall prevail. GB191-90 Pictorial markings for packaging, storage and transportation
GB3131-88Tin-lead solder
GB4722-92Test methods for copper-clad laminates for printed circuitsGB6388-86Transport packaging and delivery markings
CB949188Liquid solder for soldering (rosin based)GB10579-89General rules for inspection, packaging, marking, storage and transportation of solvent-free insulating varnishGJB244-87General specification for thin film fixed resistors with reliability indicatorsPromulgated by the Ministry of Electronics Industry of the People's Republic of China on March 11, 1998, implemented on May 1, 1998
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SJ 20671- 1998
GJB360496 Test methods for electronic and electrical components GJB1182-91 Protective packaging and packing levels GJB1651-93 Test methods for metal foil laminates for printed circuits OJ990.3-86 Test methods for coating thickness QJ990.7-86 Test methods for coating flexibility QJ990.11-86 Test methods for coating resistance to bacteria QJ990.15-86 Test methods for coating dryness SJ20224-92 Detailed specifications for flame-retardant copper foil epoxy glass cloth laminates for printed circuits 3 Requirements
3.1 Qualification appraisal
The conformal coating materials submitted in accordance with this specification shall be products that have been qualified or approved by the appraisal (see 4.5 and 6.3). 3.2 Materials
The materials shall not contain harmful components and shall be composed of synthetic resins, synthetic rubbers, plasticizers, catalysts and other components that meet the requirements of this specification. Materials shall fluoresce when exposed to ultraviolet light (except Types SR and XY) and conform to the requirements of this specification. Acceptance or approval of any component material shall not be construed as a guarantee of acceptance of the finished product. 3.2.1 Composite Coating Systems
Composite coating systems within this specification are evaluated as a single material. The primer and coating shall be prepared as recommended by the contractor. Surface preparation prior to coating is part of the complete coating procedure. When testing on pre-production boards, the complete coating procedure shall be tested.
3.3 Compatibility
Coating materials shall be suitable for printed board assembly and shall be compatible with the materials used in the printed circuit assembly (see 6.2). The coating shall not damage the materials of the printed circuit assembly and the components thereon (6.1.7). 3.4 Curing Time and Temperature
When tested as specified in 4.8.1, the coating material shall fully decompose at the temperature and time recommended by the contractor (see 6.1 and 6.2). Unless otherwise specified (see 6.2), the curing time for AR type shall not exceed 4 hours; for ER type shall not exceed 8 hours, and for SR type and UR type shall not exceed 24 hours; the curing temperature shall not exceed 125°C. XY type is directly cured by vacuum deposition.
3.5 Appearance
When inspected in accordance with 4.8.2, the coating shall be smooth, uniform, transparent, and free of dyes and pigments. It is permitted to add colorless additives to make the material "fluorescent" (see 3.2). The coating shall be free of blistering, pinholes, white spots, wrinkles, cracks, peeling, etc. The coating shall not cover or obscure the identification marks and color codes of electronic components. The discoloration of printed conductors and substrates caused by coating shall not be greater than the discoloration caused by pre-coating treatment. The coating shall not corrode the metal it covers. 3.6 Coating Thickness
When measured in accordance with 4.8.3, the coating thickness of AR, ER and UR types shall be 0.05±0.03mm; the coating thickness of SR type shall be 0.13±0.08mm; the coating thickness of XY type shall be 0.01~0.05mm3.7 Mildew Resistance
When tested in accordance with 4.8.4, the cured coating shall be able to resist the growth of industrial mildew and shall be "0" grade. 2 —
3.8 Life
SJ 20671 — 1998
When tested in accordance with 4.8.5, the appearance, insulation resistance and dielectric voltage of the coating shall comply with the provisions of 3.5, 3.9 and 3.10 respectively.
3.9 Insulation resistance
When measured in accordance with 4.8.6, unless otherwise specified, the average insulation resistance of all coated samples shall not be less than 2.5×1022; the insulation resistance value of each sample shall not be less than 1.5×10203.10 Dielectric withstand voltage
When tested in accordance with 4.8.7, there shall be no arcing (surface discharge), sparking (air discharge) or breakdown (breakdown discharge). The discharge current rating shall not exceed 10m4.3.110 Value (resonance)
When tested in accordance with 4.8.8, the average value of the percentage change of the 0 value shall not exceed the provisions of Table 1. At 1MHz and 40MHZ frequencies, the minimum 0 value of the uncoated GF type substrate (see SJ 20224) shall be 50 and 70 respectively (see 6.1.8).
Percentage change of values ​​in Table 10
Test conditions
Before and after coating
Before and after immersion (after coating, treat in
distilled water, D24/23)
Note: D-24/23 see SJ 20224
3.12 Temperature shock
Measurement frequency MHz
Maximum percentage change of Q value allowed
When tested according to 4.8.9, the appearance of the coating and the dielectric withstand voltage shall comply with 3.5 and 3.10. 3.13 Moisture resistance
When tested in accordance with 4.8.10, the appearance and dielectric voltage of the coating shall comply with 3.5 and 3.10 respectively; the average insulation resistance of all samples of AR, SR, UR and XY type coatings shall not be less than 1.0×102; ER type shall not be less than 1.0×10°Q. The insulation resistance value of any sample of AR, SR, UR and XY type coatings shall not be less than 5×10°Q: ER type shall not be less than 5×100.
3.14 Flexibility
When tested in accordance with 4.8.11, the coating shall be free of cracks and fissures. 3.15 Damp heat aging
When tested in accordance with 4.8.12, the coating shall meet the following requirements. 3.15.1 Hydrolytic stability
There shall be no softening, swelling, blistering, cracking, stickiness, loss of adhesion or liquefaction indicating changes in the coating material.
3.15.2 Fading
The clarity and resolution of the identification marks and the color codes used to distinguish the parts shall be inspected. 3.16 Non-flammability
When tested in accordance with 4.8.13, the coating shall be self-extinguishing or non-flammable. 3
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4 Quality Assurance Provisions
4.1 Inspection Responsibility
SJ 20671 - 1998
Unless otherwise specified in the contract or order, the contractor shall be responsible for completing all inspections required by this specification. Unless otherwise specified in the contract or order, the contractor may use its own or any other equipment suitable for completing the inspection requirements specified in this specification, except for equipment not approved by the relevant competent authorities. The right to conduct any inspection specified in this specification is reserved when the relevant competent authorities consider that such inspections are necessary to ensure that the supply and use meet the specified requirements. 4.1.1 Test equipment and inspection devices
The contractor shall establish and maintain test equipment, measuring equipment and inspection devices of sufficient accuracy, quality and quantity to carry out the required inspections. When, a metrological calibration system that complies with the regulations shall be established and maintained to control the accuracy of the measuring and test equipment.
4.2 Inspection classification
The inspection classification specified in this specification is as follows!
a) Material inspection (see 4.3)
b) Qualification inspection (see 4.5);
c) Quality consistency inspection (see 4.6).
4.3 Material inspection
Material inspection shall consist of a certificate supported by verification data to prove that the materials used in the coating meet the requirements specified in 1.2; 3.2 and 3.2.1. The basic materials and major auxiliary materials of each component and its coating (such as polyurethane polyether) shall be identified.
4.4 Test conditions
Unless otherwise specified in this specification, all tests shall be carried out under the standard atmospheric conditions for the tests specified in 4.1 of GIB360A.
4.5 Verification test
Verification test shall be carried out in a laboratory approved by the relevant competent authorities, and the samples used shall be produced by conventional equipment and processes in production.
4.5.1 Sample size
The coating material shall be collected in a sealed container. The number of samples to be tested shall be 28 (see 4.7) and the tests shall be carried out in accordance with the provisions of Table 2. The samples to be tested shall be: four glass plates, 16 copper-clad laminates, four tin-plated plates, and four copper-clad laminate strips. Since the XY type coating adopts the vacuum deposition method, the samples to be tested shall be provided by the contractor. 4.5.2 Test procedure
The samples shall be subjected to the tests specified in Table 2. The samples are divided into groups 1 to 7 as specified in Table 2, and each group is tested in the order shown in Table 2.
Test items
Curing time and temperature
Coating thickness
Insulation resistance
Withstand voltage
Centrifugal force (resonance)
Temperature shock
Withstand voltage
Insulation resistance
Insulation resistance
Dielectric withstand voltage
Flexibility
Wet heat aging
Flame retardancy
4.5.3 Qualification criteria
SJ 20671 -- 1998
Table 2 Qualification test
Test method
Type and number of samples to be tested
(Glass plate)
(Figure 1)
(Tinned)
[Strip]
If one or more samples fail to meet the requirements, the qualification test fails and the qualification approval cannot be given. 4.5.4 Retention of qualification data
In order to maintain the qualification, the contractor shall submit a report to the qualification agency every 24 months. The qualification agency shall specify the starting report date. The report shall include the following: 9. A summary of the test results of the Group A and Group B tests that have been carried out shall at least indicate the number of qualified batches, the number of unqualified batches and the group to which the unqualified products belong. The test results of all repair batches shall be marked and the reasons shall be stated. b. A summary of the test results of the Group C test that has been carried out shall include the number of failures and the failure mode. The summary shall include the test results of all periodic inspections conducted and completed within the 24-month period. If the test results indicate that the product does not meet the requirements of the specification and corrective actions approved by the certification body are not taken, the test will result in the removal of the non-conforming product from the catalog of qualified products. Failure to submit a report within 30 days after the end of each 24-month period may result in the loss of the product's qualification. In addition to the regular submission of inspection data, at any time during the 24-month period, once the inspection data shows that the qualified product that meets the requirements of this specification has failed, the contractor shall immediately (within 24 hours) report to the certification body: if no production is carried out within the reporting period, a report shall be submitted to prove that the contractor still has the necessary capabilities and facilities to produce such product. If production is still not carried out within a consecutive reporting period, the contractor may be required to provide products for testing in accordance with the certification inspection requirements at the discretion of the certification body. 4.6 Quality consistency inspection
4.6.1 Batch inspection
Batch inspection shall consist of Group A and Group B inspections. Batch inspection is the product delivery inspection: 4.6.1.1 Inspection batch
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SJ20671-1998
An inspection batch shall include all groups of containers containing these coating materials produced from one batch and submitted for inspection at the same time. 4.6.1.1.1 Batch
A batch (if feasible) shall include all coating materials produced from one continuous production process or two or more continuous production processes of one batch.
4.6.1.1.2 Test specimens
The number and preparation of the test specimens to be inspected shall comply with the provisions of 4.7 to 4.7.3. 4.6.1.2 Group A inspection
Group A inspection consists of the inspection items specified in Table 3 and shall be carried out in the order shown. Table 3 Group A Inspection
Inspection Items
Curing Time and Temperature
Thickness of Coating
4.6.1.2.1 Sampling Plan
Test Method
From each batch, one package of each essential component forming the coating compound shall be sampled. The number of samples in each package shall be sufficient to carry out the tests specified in Table 3. 4.6.1.2.2 Failure
If the sample fails in any test, the batch shall be rejected. 4.6.1.2.3 Rejection of Batch
If an inspection batch is rejected, the contractor may rework the batch, correct the defects or reject the defective products and resubmit it for inspection. This batch shall be separated from the new batch and clearly marked as a re-inspection batch. 4.6.1.3 Group B Inspection
Group B inspection shall consist of the inspection items specified in Table 4 and shall be carried out in the order shown. The samples submitted for Group B inspection shall be prepared from materials that have passed Group A inspection. Table 4 Group B inspection
Inspection items
Dielectric withstand voltage
Q value (resonance)
Temperature shock
Dielectric withstand voltage
Insulation resistance
Insulation resistance
Dielectric withstand voltage
Flexibility
Phosphorus resistance
Test method
4.6.1.3,1 Sampling plan
SJ 20671 --- 1998
One package of each essential component forming the coating compound shall be taken from a production batch every 12 months. The number of samples in each package shall be sufficient to carry out the tests specified in Table 4. 4.6.1.3.2 Failure
If one or more samples fail the Group B inspection, the batch shall be rejected. 4.6.1.3.3 Rejected Lots
If an inspection lot is rejected, the contractor may rework the lot, correct defects or reject defective products, and resubmit for inspection. The resubmitted lot shall be subjected to a tightened inspection. This lot shall be separated from new lots and clearly marked as a re-inspection lot.
4.6.1.3.4 Handling of Samples
If the inspection lot is accepted, samples that have passed all Group B tests may be delivered in accordance with the contract or order. 4.6.2 Qualification Verification Tests
Qualification verification tests shall consist of Group C tests. Delivery of products that have passed Group A and Group B tests shall not be postponed until the results of the qualification verification tests are obtained, unless the test results indicate that the product does not meet the requirements (see 4.6.2.1.4). 4.6.2.1 Group C Tests
Group C tests shall consist of the tests and tests specified in Table 5 and shall be performed in the order shown. The samples submitted for Group C inspection shall be prepared from coating materials sampled from inspection lots that have passed Group A and Group B inspections. 4.6.2.1.1 Sampling plan
One package of each necessary component that forms the coating compound shall be sampled once every 24 months. The number of samples in each package shall be sufficient to carry out the tests specified in Table 5. Table 5 Group C inspection
Inspection items
Wet heat aging
Insulation resistance
Dielectric withstand voltage
4.6.2.1.2 Failure
If one or more inspection items fail, the sample shall be deemed unqualified. 4.6.2.1.3 Handling of samples
Samples that have passed all Group C inspections may be delivered in accordance with the contract or order. 4.6.2.1.4 Nonconformity
Test Method
If a sample fails the Group C test, the contractor shall report the nonconformity to the certification body and the relevant competent authorities and take corrective action on the materials and workmanship, based on the cause of the nonconformity, for all products manufactured with substantially the same materials and workmanship under substantially the same conditions and considered to have undergone repair of the phase-to-phase nonconformity. Acceptance and delivery of the products shall be suspended until corrective action approved by the certification body is taken. After corrective action is taken, the additional samples shall be re-tested with Group C ITKAONKAca-
SI 20671 — 1998
(all items or the date of the original sample nonconformity, as determined by the certification body). At the same time, Group A and Group B tests may be restarted, but final acceptance and delivery shall not be made until the Group C re-test shows that the corrective action has been successful. If nonconformity is still present after re-testing, the relevant nonconformity information and corrective action taken shall be provided to the certification body and the relevant competent authorities.
4.6.3 Packaging inspection
The packaging and packing of samples, as well as the inspection, storage and transportation of protective packaging and the marking of packaging shall comply with the provisions of CB10579 and GB191.
4.7 Preparation of test specimens
4.7.1 Pretreatment before coating
4.7.1.1 Test pattern
The test pattern is shown in Figure 1.
38.0 ± 1.5
Pad Φ2.29±0.13
Hole 20.70±0.10
Minimum 0.76
0.76 ± 0.08
Note: Dimensions are in mm
Minimum 0.76
Pad Φ3.81 ± 0.13
1.30 ± 0.10
Figure丨Test Pattern
SJ 20671 -- 1998
The sample is made of GF epoxy glass cloth laminate with single-sided 70um copper foil in accordance with SJ20224. Only in the wet heat aging test, the sample is plated with tin-lead (Sn60) plating in accordance with the relevant specifications. The production steps of the test pattern sample are as follows.
a. Etch the printed circuit pattern according to Figure 1. The cleaning method of the sample after etching is as follows: (1) Immerse in a solvent that is usually used to clean printed boards and printed board assemblies at room temperature: (2) Dry at room temperature;
(3) Immerse in hydrochloric acid with a specific gravity of 1.033 at 23°C for 10 seconds. (Prepared by 1 part hydrochloric acid with a specific gravity of 1.180 and 4 parts water)
(4) Wash with distilled water;
(5) Dry in clean air or inert gas. b. The lead should be inserted from the side of the laminate without copper foil and connected to the connection pad with solder: The soldering should use S-type solder of Sn63 or Sn60 that meets the requirements of GB3131, or R-type or RMA-type flux core solder. When using S-type solder, the flux used should meet the requirements of CB9491. Only in the damp heat aging test, each test board shall be welded with a thin film fixed resistor coated with insulating compound with reliability index and a resistor in accordance with CJB244 (the selected resistor color code shall be indicated in the test report.
C. After welding, wipe the test board with a solvent that is usually used to clean printed boards and printed board assemblies. d. Place the test strip in an oven at 123±2℃ with air circulation for 1h. The environmental conditions shall comply with the provisions of 4.4.
4.7. 1.2 Test strips
The samples shall be made of CF-type epoxy glass cloth laminate with 70gm copper foil on one side in accordance with SJ20224. The test strips shall be prepared as follows:
a. The test strips in accordance with SJ20224 shall be 127mm long and 12.7mm wide, and all copper shall be etched away. b. Place the test strips in an oven at 123±29 with air circulation for 1 hour. The environmental conditions shall comply with the provisions of 4.4.
4.7.1.3 Glass
The surface of the glass plate should be flat, smooth and clean. 4.7.1.4 Tinned plate
The tinned test plate should comply with the provisions of QJ990.7 and the thickness should not be less than 0.1nml. Electroplating tin is allowed: 4.7.2 Coating (see 3.2.1)
The coating should be applied on both sides and all edges of the sample. The curing time and temperature of the coating should follow the recommendations of the contractor. The coating thickness should comply with the provisions of 3.6. 4.7.3 Number of samples
The number of samples should comply with Table 2 and 4.5 .1. 4.8 Test methods
4.8.1 Curing time and temperature (see 3.4) The coating material shall be tested in accordance with the contractor's recommendations or product instructions. 4.8.2 Appearance (see 3.5)
The appearance shall be inspected daily under ultraviolet light with a 10x magnifying glass, but SR and XY type coatings shall be inspected under natural light. Use standard vision or corrected 2.0/2.0 vision to check for bubbles: The coating shall be inspected for pinholes, white spots, bubbles, wrinkles, -9—
TTTKAONTKAca-4 Nonconformity
Test Method
If a sample fails the Group C test, the contractor shall report the nonconformity to the certification body and the relevant competent authorities and take corrective measures for the materials and processes, and for all products manufactured with substantially the same materials and processes under substantially the same conditions and considered to have undergone repair of the phase nonconformity, based on the cause of the nonconformity. Acceptance and delivery of products shall be suspended until corrective measures approved by the certification body are taken. After the corrective measures are taken, the additional samples shall be re-tested with Group C ITKAONKAca-
SI 20671 — 1998
(all items or the date of the original sample nonconformity, as determined by the certification body). At the same time, Group A and Group B tests may be restarted, but final acceptance and delivery shall not be made until the Group C re-test shows that the corrective measures have been successful. If the re-test still fails, the relevant nonconformity information and corrective measures taken shall be provided to the certification body and the relevant competent authorities.
4.6.3 Packaging inspection
The packaging and packing of samples, as well as the inspection, storage and transportation of protective packaging and the marking of packaging shall comply with the provisions of CB10579 and GB191.
4.7 Preparation of test specimens
4.7.1 Pretreatment before coating
4.7.1.1 Test pattern
The test pattern is shown in Figure 1.
38.0 ± 1.5
Pad Φ2.29±0.13
Hole 20.70±0.10
Minimum 0.76
0.76 ± 0.08
Note: Dimensions are in mm
Minimum 0.76
Pad Φ3.81 ± 0.13
1.30 ± 0.10
Figure丨Test Pattern
SJ 20671 -- 1998
The sample is made of GF epoxy glass cloth laminate with single-sided 70um copper foil in accordance with SJ20224. Only in the wet heat aging test, the sample is plated with tin-lead (Sn60) plating in accordance with the relevant specifications. The production steps of the test pattern sample are as follows.
a. Etch the printed circuit pattern according to Figure 1. The cleaning method of the sample after etching is as follows: (1) Immerse in a solvent that is usually used to clean printed boards and printed board assemblies at room temperature: (2) Dry at room temperature;
(3) Immerse in hydrochloric acid with a specific gravity of 1.033 at 23°C for 10 seconds. (Prepared by 1 part hydrochloric acid with a specific gravity of 1.180 and 4 parts water)
(4) Wash with distilled water;
(5) Dry in clean air or inert gas. b. The lead should be inserted from the side of the laminate without copper foil and connected to the connection pad with solder: The soldering should use S-type solder of Sn63 or Sn60 that meets the requirements of GB3131, or R-type or RMA-type flux core solder. When using S-type solder, the flux used should meet the requirements of CB9491. Only in the damp heat aging test, each test board shall be welded with a thin film fixed resistor coated with insulating compound with reliability index and a resistor in accordance with CJB244 (the selected resistor color code shall be indicated in the test report.
C. After welding, wipe the test board with a solvent that is usually used to clean printed boards and printed board assemblies. d. Place the test strip in an oven at 123±2℃ with air circulation for 1h. The environmental conditions shall comply with the provisions of 4.4.
4.7. 1.2 Test strips
The samples shall be made of CF-type epoxy glass cloth laminate with 70gm copper foil on one side in accordance with SJ20224. The test strips shall be prepared as follows:
a. The test strips in accordance with SJ20224 shall be 127mm long and 12.7mm wide, and all copper shall be etched away. b. Place the test strips in an oven at 123±29 with air circulation for 1 hour. The environmental conditions shall comply with the provisions of 4.4.
4.7.1.3 Glass
The surface of the glass plate should be flat, smooth and clean. 4.7.1.4 Tinned plate
The tinned test plate should comply with the provisions of QJ990.7 and the thickness should not be less than 0.1nml. Electroplating tin is allowed: 4.7.2 Coating (see 3.2.1)
The coating should be applied on both sides and all edges of the sample. The curing time and temperature of the coating should follow the recommendations of the contractor. The coating thickness should comply with the provisions of 3.6. 4.7.3 Number of samples
The number of samples should comply with Table 2 and 4.5 .1. 4.8 Test methods
4.8.1 Curing time and temperature (see 3.4) The coating material shall be tested in accordance with the contractor's recommendations or product instructions. 4.8.2 Appearance (see 3.5)
The appearance shall be inspected daily under ultraviolet light with a 10x magnifying glass, but SR and XY type coatings shall be inspected under natural light. Use standard vision or corrected 2.0/2.0 vision to check for bubbles: The coating shall be inspected for pinholes, white spots, bubbles, wrinkles, -9—
TTTKAONTKAca-4 Nonconformity
Test Method
If a sample fails the Group C test, the contractor shall report the nonconformity to the certification body and the relevant competent authorities and take corrective measures for the materials and processes, and for all products manufactured with substantially the same materials and processes under substantially the same conditions and considered to have undergone repair of the phase nonconformity, based on the cause of the nonconformity. Acceptance and delivery of products shall be suspended until corrective measures approved by the certification body are taken. After the corrective measures are taken, the additional samples shall be re-tested with Group C ITKAONKAca-
SI 20671 — 1998
(all items or the date of the original sample nonconformity, as determined by the certification body). At the same time, Group A and Group B tests may be restarted, but final acceptance and delivery shall not be made until the Group C re-test shows that the corrective measures have been successful. If the re-test still fails, the relevant nonconformity information and corrective measures taken shall be provided to the certification body and the relevant competent authorities.
4.6.3 Packaging inspection
The packaging and packing of samples, as well as the inspection, storage and transportation of protective packaging and the marking of packaging shall comply with the provisions of CB10579 and GB191.
4.7 Preparation of test specimens
4.7.1 Pretreatment before coating
4.7.1.1 Test pattern
The test pattern is shown in Figure 1.
38.0 ± 1.5
Pad Φ2.29±0.13
Hole 20.70±0.10
Minimum 0.76
0.76 ± 0.08
Note: Dimensions are in mm
Minimum 0.76
Pad Φ3.81 ± 0.13
1.30 ± 0.10
Figure丨Test Pattern
SJ 20671 -- 1998
The sample is made of GF epoxy glass cloth laminate with single-sided 70um copper foil in accordance with SJ20224. Only in the wet heat aging test, the sample is plated with tin-lead (Sn60) plating in accordance with the relevant specifications. The production steps of the test pattern sample are as follows.
a. Etch the printed circuit pattern according to Figure 1. The cleaning method of the sample after etching is as follows: (1) Immerse in a solvent that is usually used to clean printed boards and printed board assemblies at room temperature: (2) Dry at room temperature;
(3) Immerse in hydrochloric acid with a specific gravity of 1.033 at 23°C for 10 seconds. (Prepared by 1 part hydrochloric acid with a specific gravity of 1.180 and 4 parts water)
(4) Wash with distilled water;
(5) Dry in clean air or inert gas. b. The lead should be inserted from the side of the laminate without copper foil and connected to the connection pad with solder: The soldering should use S-type solder of Sn63 or Sn60 that meets the requirements of GB3131, or R-type or RMA-type flux core solder. When using S-type solder, the flux used should meet the requirements of CB9491. Only in the damp heat aging test, each test board shall be welded with a thin film fixed resistor coated with insulating compound with reliability index and a resistor in accordance with CJB244 (the selected resistor color code shall be indicated in the test report.
C. After welding, wipe the test board with a solvent that is usually used to clean printed boards and printed board assemblies. d. Place the test strip in an oven at 123±2℃ with air circulation for 1h. The environmental conditions shall comply with the provisions of 4.4.
4.7. 1.2 Test strips
The samples shall be made of CF-type epoxy glass cloth laminate with 70gm copper foil on one side in accordance with SJ20224. The test strips shall be prepared as follows:
a. The test strips in accordance with SJ20224 shall be 127mm long and 12.7mm wide, and all copper shall be etched away. b. Place the test strips in an oven at 123±29 with air circulation for 1 hour. The environmental conditions shall comply with the provisions of 4.4.
4.7.1.3 Glass
The surface of the glass plate should be flat, smooth and clean. 4.7.1.4 Tinned plate
The tinned test plate should comply with the provisions of QJ990.7 and the thickness should not be less than 0.1nml. Electroplating tin is allowed: 4.7.2 Coating (see 3.2.1)
The coating should be applied on both sides and all edges of the sample. The curing time and temperature of the coating should follow the recommendations of the contractor. The coating thickness should comply with the provisions of 3.6. 4.7.3 Number of samples
The number of samples should comply with Table 2 and 4.5 .1. 4.8 Test methods
4.8.1 Curing time and temperature (see 3.4) The coating material shall be tested in accordance with the contractor's recommendations or product instructions. 4.8.2 Appearance (see 3.5)
The appearance shall be inspected daily under ultraviolet light with a 10x magnifying glass, but SR and XY type coatings shall be inspected under natural light. Use standard vision or corrected 2.0/2.0 vision to check for bubbles: The coating shall be inspected for pinholes, white spots, bubbles, wrinkles, -9—
TTTKAONTKAca-4) The coating material shall be tested in accordance with the manufacturer's recommendations or product instructions. 4.8.2 Appearance (see 3.5)
Appearance shall be inspected daily under ultraviolet light with a 10x magnifying glass, but SR and XY type coatings shall be inspected under natural light. Use standard vision or corrected 2.0/2.0 vision to check for bubbles: The coating shall be inspected for pinholes, white spots, bubbles, wrinkles, -9—
TTTKAONTKAca-4) The coating material shall be tested in accordance with the manufacturer's recommendations or product instructions. 4.8.2 Appearance (see 3.5)
Appearance shall be inspected daily under ultraviolet light with a 10x magnifying glass, but SR and XY type coatings shall be inspected under natural light. Use standard vision or corrected 2.0/2.0 vision to check for bubbles: The coating shall be inspected for pinholes, white spots, bubbles, wrinkles, -9—
TTTKAONTKAca-
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