GB/T 3131-2020 Tin-lead solder
1 Scope
This standard specifies the classification and designation, technical requirements, test methods, inspection rules, marking, packaging, transportation, storage, certificate of quality, and the content of purchase order (or contract) for tin-lead solder.
This standard is applicable to tin-lead solder used for welding in electronic and electrical equipment, communication equipment and other machinery manufacturing.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 2828.1 Sampling procedures for inspection by attributes - Part 1: Sampling schemes indexed by acceptance quality limit (AQL) for lot-by-lot inspection
GB/T 8170 Rules of rounding off for numerical values & expression and judgment of limiting values
GB/T 10574.1-2003 Methods for chemical analysis of tin-lead solders - Determination of tin content
GB/T 10574.2-2003 Methods for chemical analysis of tin-lead solders - Determination of antimony content
GB/T 10574.3-2003 Methods for chemical analysis of tin-lead solders - Determination of bismuth content
GB/T 10574.4-2003 Methods for chemical analysis of tin-lead solders - Determination of iron content
GB/T 10574.5-2003 Methods for chemical analysis of tin-lead solders - Determination of arsenic content
GB/T 10574.6-2003 Methods for chemical analysis of tin-lead solders - Determination of copper content
GB/T 10574.7-2017 Methods for chemical analysis of tin-lead solders - Part 7: Determination of silver content - Flame atomic absorption spectrometry and potassium thiocyanate potentiometric titration
GB/T 10574.8-2017 Methods for chemical analysis of tin-lead solders - Part 8: Determination of zinc content - Flame atomic absorption spectrometric method
GB/T 10574.9-2017 Methods for chemical analysis of tin-lead solders - Part 9: Determination of aluminium content - Graphite furnace atomic absorption spectrometric method
GB/T 10574.10-2017 Methods for chemical analysis of tin-lead solders - Part 10: Determination of cadmium content - Flame atomic absorption spectrometry and Na2EDTA titration method
GB/T 10574.11-2017 Methods for chemical analysis of tin-lead solders - Part 11: Determination of phosphorus content - Crystal violet phosphorus-vanadium-molybdeum heteropoly acid spectrophotometry
GB/T 10574.12-2017 Methods for chemical analysis of tin-lead solders - Part 12: Determination of sulfur content - High frequency combustion with infrared absorption method
GB/T 10574.13-2017 Methods for chemical analysis of tin-lead solders - Part 13: Determination of antimony, bismuth, iron, arsenic, copper, silver, zinc, aluminium, cadmium, phosphorous and gold contents - Inductively coupled plasma atomic emission spectrometric method
GB/T 10574.14-2017 Methods for chemical analysis of tin-lead solders - Part 14: Determination of tin, lead, antimony, bismuth, silver, copper, zinc, cadmium and arsenic content - Optical emission spectrometry
GB/T 15829 Soft soldering flux - Classification and requirements
3 Classification and designation
3.1 Product classification
3.1.1 The classification and specifications of tin-lead solder are shown in Table 1.
Table 1 Classification and specifications of tin-lead solder
Product type Shape Specification
mm
Flux-free solid core solder Wire form Diameter: 0.1~6.0
Other shapes including bar, rod, strip, sheet, ring, etc. Subject to negotiation between the manufacturer and the purchaser
Flux-containing cored solder Wire form Diameter: 0.1~6.0
Shapes including strip, sheet, ring, etc. Subject to negotiation between the manufacturer and the purchaser
3.1.2 The types of resin-cored flux are shown in Table 2, and other types of flux shall be subject to negotiation between the manufacturer and the purchaser.
Table 2 Types of resin-cored flux
Type Type code Application
Pure resin-based flux R For applications with extremely strict requirements on corrosion, insulation resistance and other properties
Moderately activated resin-based flux RMA For applications with high requirements on insulation resistance
Activated resin-based flux RA For high-efficiency soldering applications
3.2 Grade designation
3.2.1 Method for grade designation
The grade of tin-lead solder consists of two parts. The two parts of the solder grade are separated by a hyphen "-", with details as follows:
a) The first part of the solder grade uses "S" to represent solder;
b) The second part of the solder grade consists of the chemical element symbols of the main alloy components. In this part, the first chemical element symbol is Sn, and other element symbols are listed in the order of their mass fractions. Where several elements have the same mass fraction, they shall be arranged in the order of their atomic numbers.
c) Elements with a nominal mass fraction of less than 1% do not need to be indicated in the grade. If an element is a key component of the solder and must be indicated, its chemical element symbol may be marked.
d) The last part of the grade, namely AA, A and B, indicates the quality grade of the solder.
3.2.2 Example of grade designation
An example of a complete solder grade is given below:
S-Sn95PbA
Contents
Foreword i
1 Scope
2 Normative references
3 Classification and designation
4 Technical requirements
5 Test methods
6 Inspection rules
7 Marking, packaging, transportation, storage and quality certificate
8 Content of purchase order (or contract)
Annex A (Informative) Physical properties and main applications of tin-lead solder
Annex B (Normative) Test method for flux content
