Low silver leadless solder and preparation

Abstract

The invention pertains to electronic solder technique field, and is a modified technique based on prior art, specifically relates to a low-silver leadless solder and preparing method thereof. The components and weight percent of the low-silver leadless solder are: 0.1-0.61f Ag, 0.45-0.79514612004f Cu, 1-51f Bi, 0.02-0.226154000f P, 0.02-0.09150547514f lanthanum-cerium mixed rare earth (RE), residue percent of Sn, and weight sum of each component is 100 In the precondition that the Ag content is decreased remarkably and the welding material cost is saved, the solder with a moderate fusion point, good antioxygenic property, excellent braze welding technique property and integrate mechanical property is obtaind. The invented braze welting material is provided with a stable property, a low cost and broad market application foreground.

Description

technical field [0001] The invention belongs to the technical field of solder and improves the prior art, and in particular relates to a low-silver lead-free solder and a preparation method thereof. Background technique [0002] Lead-free solder solder is widely used in the electronics industry, and the soldering of circuit boards. Its shortcoming is that the lead-free solder commonly used at present, such as the melting points of Sn-3.5Ag and Sn-3.0Ag-0.5Cu alloys are respectively 221 ℃, 217 ℃, compared with the traditional Sn-Pb solder, its melting point rises by about 40 ℃, so it will inevitably lead to an increase in the brazing temperature, which puts forward a higher temperature resistance for electronic components and circuit board materials. At the same time, due to the narrow window of brazing process parameters, existing brazing equipment needs to be upgraded or repurchased; in addition, because these lead-free solders contain more precious metal silver, the cost o...

AI Technical Summary

Problems solved by technology

[0002] Lead-free solder solder is widely used in the electronics industry, and the soldering of circuit boards. Its shortcoming is that the lead-free solder commonly used at present, such as the melting points of Sn-3.5Ag and Sn-3.0Ag-0.5Cu alloys are respectively 221 ℃, 217 ℃, compared with the traditional Sn-Pb solder, its melting point rises by about 40 ℃, so it will inevitably lead to an increase in the brazing temperature, which puts forward a higher temperature resistance for electronic components and circuit board materials. At the same time, due to the narrow window of brazing process parameters, existing brazing equipment needs to be upgraded or repurchased; in addition, because these lead-free solders contain more precious metal silver, the cost of materials is high

The above patents limit the P content in the solder to an extremely difficult to control range of 0.0005 to 0.0008% by weight

Even if the intermediate alloy is used to prepare, it is difficult to ensure the content of P in the solder, which makes the solder unfavorable for practical application

In addition, although the Ag content of this patent is lower than that of Sn-3.5Ag and Sn-3.0Ag-0.5Cu, the cost of solder is still high due to the high price of Ag