CN101780608B

CN101780608B - SnAgCu series lead-free solder containing Si and Ge

Info

Publication number: CN101780608B
Application number: CN2010101440161A
Authority: CN
Inventors: 丁清峰; 严剑; 赵伟明
Original assignee: TIANJIN HENKO TECHNOLOGY Co Ltd
Current assignee: TIANJIN HENKO TECHNOLOGY Co Ltd
Priority date: 2010-04-12
Filing date: 2010-04-12
Publication date: 2011-09-21
Anticipated expiration: 2030-04-12
Also published as: CN101780608A

Abstract

The invention relates to a SnAgCu series lead-free solder containing Si and Ge, which is characterized in that the lead-free solder is composed of 0.1-2.0% of Ag, 0.5-0.9% of Cu, 0.001-0.01% of Si, 0.001-0.01% of Ge, 0.01-0.05% of Ni, 0.001-0.01% of P and the balance of Sn or is composed of 0.1-2.0% of Ag, 0.5-0.9% of Cu, 0.001-0.01% of Si, 0.001-0.01% of Ge, 0.01-0.05% of Co, 0.001-0.01% of P and the balance of Sn, the lead-free solder has the advantages of high degree of alloying, even and fine solder crystal structure and low cost, which can prevent fusion Cu and significantly improve the wettability, the weldability and oxidation resistance of the solder.

Description

A kind of SnAgCu series lead-free solder that contains Si and Ge

Technical field

The present invention relates to the SnAgCu series lead-free solder of a kind of Si of containing and Ge, belong to leadless welding material.

Background technology

Pay attention to environmental protection; advocating green product is the main trend of current world economy development; answer the demand for development of global environmental protection method and electronic information and electrical apparatus industry; electronics and IT products and electric equipment products are realized that unleaded is a kind of inexorable trend; the research and development high-performance; low-cost; the low-silver lead-free solder that satisfies practicality and high reliability request also is domestic and international development trend; the present high Sn4.8Ag0.7 of silver content; the Sn3Ag0.5 series lead-free solder occupies very great share on market; because this scolder argentiferous height; the cost height; can't be accepted by the domestic user; in the particularly present wave-soldering technology; expectation to low-silver lead-free solder is very high; its consumption is big; it is particularly important that the material cost problem seems; and silver is noble metal; its resource-constrained; with rapid economy development; every profession and trade increases substantially to the demand of Ag; its price changes with economy and sharp rises; make present nearly one times of the silver lead-free solder cost increase that contains; therefore research and develop high-performance; low-cost; the low Ag lead-free solder of practical second generation SnAgCu is the common problem of paying close attention to of welding material industry and user; the low Ag lead-free solder of research and development a new generation is met the need of market, and environmental protection is practical more economically more to make lead-free solder.

Summary of the invention

Purpose of the present invention is the shortcoming and deficiency in order to overcome above-mentioned prior art just, and provide that a kind of antioxygenic property is good, silver content is low, fusing point, wetability is better, practical, service-strong contains Si and Ge SnAgCu series lead-free solder, reduced cost, satisfy the instructions for use of wave-soldering technology again, also can be applicable to multiple welding material product and use.

The objective of the invention is to realize by following technical proposal:

A kind of SnAgCu series lead-free solder that contains Si and Ge, it is made up of following weight percentages:

Ag?0.1～2.0％、Cu?0.5～0.9％、Si?0.001～0.01％、

Ge 0.001～0.01%, Ni 0.01～0.05%, P 0.001～0.01% and surplus Sn.

The percentage by weight of described each component of raw material be:

Ag?0.1～2.0％、Cu?0.5～0.9％、Si?0.001～0.01％、

Ge 0.001～0.01%, Co 0.01～0.05%, P 0.001～0.01% and surplus Sn.

Lead-free solder of the present invention is to have carried out the parameter levelling and replenish perfect on the lead-free solder basis of SnAgCu system, and add Si and Ge element after reducing silver-colored consumption, when utilizing semimetal Si and Ge element from solid-liquid phase change, the characteristics of fusing back volume-diminished play mutual metamorphism in the SnAgCu series lead-free solder, impel the obvious refinement of this lead-free solder crystalline structure, obvious refinement β Sn primary phase in scolder, distribute more even to metallic compound in the scolder, form the eutectic of tiny dispersion, and play and prevent the heat development of oxide in the process of solder alloy, formed the SnAgCuSiGe lead-free solder of excellent performance.

In the SnAgCuSiGe lead-free solder, add Ni and P or Co and P element, form SnAgCuSiGeNiP, SnAgCuSiGeCoP series leadless solder products with varying degrees, add Ni, Co can obviously improve the crystalline state of solder alloy, utilize Ni, the atomic radius of Co and Cu atoms of elements radius are near having very strong displacement characteristic, played the formation that suppresses Cu6Sn5 cylindrulite phase in the scolder and grown up, form stable (Ni, Cu) 6Sn5 phase and (Co, Cu) 6Sn5 phase metallic compound, having improved scolder crystalline structure and flowability improves, and improved the form of weld interface metal compound layer, boundary layer becomes level and smooth by male and fomale(M﹠F), provide advantage for improving reliability, Ni of the present invention or Co consumption respectively are 0.01～0.05%; The P element that adds can better improve the antioxygenic property and the wetability of scolder, consumption is 0.001～0.01%, by adding in the low SnAgCu lead-free solder of above-mentioned Si, Ge, Ni, Co, P element and silver content, can satisfy and realize the very Practical Performance requirement of lead-free solder of low silver.

The SnAgCu series lead-free solder that contains Si and Ge and Ni and P or Co and P of the present invention, its alloying level height, the even refinement of scolder crystalline structure, prevent the effect of fusion Cu, solder wettability, weldability, oxidation resistance increase substantially, and cost is low, can satisfy the instructions for use of wave-soldering technology, can be applicable to multiple welding material product, the low Ag Pb-free solder powder of do not have a burning bar of lead as hanging down Ag, hang down the Ag lead-free soldering wire, soldering paste being used.

Lead-free solder of the present invention adopts the normal production method preparation of SnAgCu series lead-free solder, intermediate alloy is made in Si, Ge, Ni, Co and P employing earlier to add again, promptly make the Cu-16%Si intermediate alloy, Sn-2%Ge intermediate alloy, Sn-2%Ni, Sn-2%Co intermediate alloy and Sn-5%P intermediate alloy have guaranteed the workmanship of lead-free solder.

Have following advantage and effect owing to take technique scheme that the present invention is compared with technology:

(a) this leadless welding alloy degree height, the even refinement of scolder crystalline structure prevent that fusion Cu, solder wettability, weldability, oxidation resistance increase substantially, and cost is low, satisfies the instructions for use of wave-soldering technology;

(b) with the contrast of existing scolder, strength of connection, percentage elongation creep rupture time is improved, copper fusion amount subtract beat, 4 hours oxidizing slags of immersed solder reduce, its fusing point and density near and raising arranged.

The specific embodiment

Table 1 is formed consumption for the embodiment raw material

Press the foregoing description raw material consumption, intermediate alloy is made in Si, Ge, Ni, Co, Cu and P employing earlier added again, promptly make the Cu-16%Si intermediate alloy, Sn-2%Ge intermediate alloy, Sn-2%Ni intermediate alloy, Sn-2%Co intermediate alloy and Sn-5%P intermediate alloy carry out melting.

The product scolder of embodiment 1-8 melts flow point: 217 ℃ of solidus, and liquidus curve 222-227 ℃, ℃, embodiment and prior art performance comparison result see Table 2

Table 2 is embodiment and prior art performance comparison result

Comparative Examples 1# component is Sn99%, Ag0.3%, Cu0.7%, and Comparative Examples 2# component is Sn96.5%, Ag3.0%, Cu0.5%, and the product scolder of Comparative Examples 1-2 melts flow point: 217 ℃ of solidus, 217～227 ℃ of liquidus curves.

Comparing result shows and existing scolder contrast, strength of connection improves 2～10 (N/mm2), percentage elongation improves 5～10 (%), creep rupture time raising 21.8～23.1 (hr), copper fusion amount reduction by 40～50%, immersed solder oxidizing slag reduction by 42～43% in 4 hours, and its fusing point and density are approaching.

Claims

1. SnAgCu series lead-free solder that contains Si and Ge is characterized in that it is made up of following weight percentages:

Ag?0.1～2.0％、Cu?0.5～0.9％、Si?0.001～0.01％、

Ge 0.001～0.01%, Ni 0.01～0.05%, P 0.001～0.01% and surplus Sn.

2. SnAgCu series lead-free solder that contains Si and Ge is characterized in that it is made up of following weight percentages:

Ag?0.1～2.0％、Cu?0.5～0.9％、Si?0.001～0.01％、

Ge 0.001～0.01%, Co 0.01～0.05%, P 0.001～0.01% and surplus Sn.