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ASTM B579-22
Standard Specification for Electrodeposited Coatings of Tin-Lead Alloy (Solder Plate)
Přeložit název
NORMA vydána dne 1.5.2022
Informace o normě:
Označení normy: ASTM B579-22
Datum vydání normy: 1.5.2022
Kód zboží: NS-1058363
Počet stran: 5
Přibližná hmotnost: 15 g (0.03 liber)
Země: Americká technická norma
Kategorie: Technické normy ASTM
Kategorie - podobné normy:
Anotace textu normy ASTM B579-22 :
This specification establishes the requirements for mat, bright, and flow-brightened electrodeposited tin-lead alloy coatings on fabricated articles of iron, steel, copper, and copper alloys to protect them against corrosion, to improve and preserve solderability over long periods of storage, and to improve anti-galling characteristics. Sheets, strips, or wires in the unfabricated form, or threaded articles having a specified diameter, are not covered here. The classification notation shall include the type of basis metal, thickness of tin-lead coating required, service condition number indicating the severity of service required, and coating composition. Coatings shall be sampled, tested, and shall conform accordingly to specified requirements as to composition, appearance, thickness, adhesion (to be examined either by burnishing test, quenching test, reflow test, or bend test), and solderability (to be assessed either by non-automated or automated dip test, spread test, globule test, or artificial aging test).
Keywords:
electrodeposited coatings, tin-lead alloy (solder plate), solder, tin-lead alloy, tin-lead ,, ICS Number Code 25.220.40 (Metallic coatings)
Doplňující informace
| 1. Scope | ||||||||||||||||||||||||||
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1.1?This specification covers the requirements for electrodeposited tin-lead coatings on fabricated articles of iron, steel, copper, and copper alloys, to protect them against corrosion (Note 1), to improve and preserve solderability over long periods of storage, and to improve anti-galling characteristics. Note 1:?Some corrosion of tin-lead coatings may be expected in
outdoor exposure. In normal indoor exposure, tin-lead is protective
on iron, copper, and copper alloys. Corrosion may be expected at
discontinuities (pits or pores) in the coating. Porosity decreases
as the thickness is increased. A primary use of the tin-lead
coating (solder) is with the printed circuit industry as a
solderable coating and as an etch mask material.
1.2?This specification applies to electrodeposited coatings containing a minimum of 50 % and a maximum of 70 % tin. The specification applies to mat, bright, and flow-brightened tin-lead coatings. Note 2:?Tin-lead plating baths are composed of tin and lead
fluoborates and of addition agents to promote stability. The final
appearance may be influenced by the addition of proprietary
brighteners. Without brighteners, the coatings are mat; with
brighteners, they are semibright or bright. Flow-brightened
coatings are obtained by heating mat coatings to above the melting
point of tin-lead for a few seconds and then quenching; palm oil,
hydrogenated oils, or fats are used as a heat-transfer medium at a
temperature of 260 ? 10 ?C (500 ? 20 ?F), but other methods of
heating are also in use. The maximum thickness for flow-brightening
is about 7.5 ?m (0.3 mil); thicker coatings tend to reflow
unevenly. The shape of the part is also a factor; flat surfaces
tend to reflow more unevenly than wires or rounded shapes
(Note 3).
Note 3:?Volatile impurities in tin-lead coatings will cause
bubbling and foaming during flow-brightening resulting in voids and
roughness. The impurities can arise from plating solution addition
agents and from improper rinsing and processing.
1.3?This specification does not apply to sheet, strip, or wire in the unfabricated form or to threaded articles having basic major diameters up to and including 19 mm (0.75 in.). 1.4?This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.5?This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee. |
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| 2. Referenced Documents | ||||||||||||||||||||||||||
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