CN1806997A - Lead-free solder - Google Patents

Abstract

The invention relates to a leadless tin soldering material which comprises the constituents (by mass ratio) of Ni 0.01-0.15%, Cu 0.1-2%, In 0.0001-1%, P 0.0001-1%, and balancing Sn. The preparing process of the soldering material comprises weighing 0.4-6 parts of Sn-Ni intermediate alloy ingot containing Ni 2.5%, 1-20 parts of Sn-Cu intermediate alloy ingot containing Cu 10%, 0.002-20 parts of Sn-In intermediate alloy ingot containing In 5%, P 0.0001-1 part, and balancing Sn in the whole 100 parts, charging the alloy ingots and balancing Sn into stainless crucible, elevating the temperature to 450 deg. C for smelting, agitating 30 minutes, cooling down slowly and homogeneously to 340 deg C, charging weighed P and stirring homogeneously, finally pouring the melted liquid into dies.

Description

A kind of lead-free solder

Technical field

The present invention relates to welding material, particularly a kind of lead-free tin solder belongs to the ashbury metal field.

Background technology

Along with developing rapidly of electronics industry, requirement to electronic product is more and more higher. and the used scolder kind of present electronic product is a lot, but great majority still use tin one metal scolder, because tin-lead solder is leaded to have pollution to environment, be pernicious to people, thereby a lot of country begins to ban use of solder containing pb.And existing lead-free solder majority is Xi-Yin, tin-copper, tin-silver-copper, tin-zinc-indium-bismuth, tin-silver alloy, and its weak point is the fusing point height that has, and the wetability that has is little, the cost height that has.

Summary of the invention

The objective of the invention is to overcome the shortcoming and the weak point of above-mentioned prior art, provide that a kind of to have a fusing point low, wetability is good, the lead-free solder that cost is low, thus the welding material of high-quality is provided for the processing and manufacturing of electronic product.

Purpose of the present invention is achieved through the following technical solutions:

A kind of lead-free solder, its constituent mass percentage is: nickel 0.01-0.15%, copper 0.1-2%, indium 0.0001-1%, phosphorus 0.0001-1%, surplus is a tin; The preparation method of this scolder is as follows:

The preparation method of this scolder is as follows:

(1) refined tin of stanniferous 99.95% is added is warming up to 1600 ℃ after melting in the graphite crucible and adds nickeliferous 99.95% smart nickel again, the mass ratio of its nickel consumption and tin is 2.5: 97.5, stirring with wooden stirring rod is smelted into the liquid tin nickel alloy, leaves standstill to cast nickeliferous 2.5% tin nickel intermediate alloy ingot after 30 minutes;

(2) refined tin of stanniferous 99.95% is added be warming up to 1100 ℃ of smart copper that add cuprics 99.95% after melting in the graphite pincers crucible, the mass ratio of its copper and tin is 10: 90, be smelted into the liquid tin copper alloy with wooden stirring, leave standstill the tin copper intermediate alloy ingot of casting cupric 10% after 30 minutes;

(3) the tin grain with stanniferous 99.95% is put in the Muffle furnace with the indium grain that contains indium 99.95%, and wherein the mass ratio of tin and indium is 95: 5, and smelting temperature is 350 ℃, be incubated 2 hours, stirred 30 minutes, left standstill 30 minutes, the tin indium intermediate alloy ingot that contains indium 5% is cast in the cooling of coming out of the stove;

(4) take by weighing the tin nickel intermediate alloy ingot 0.4-6 part of (1) by quality, the tin copper intermediate alloy ingot 1-20 part of (2), the tin indium intermediate alloy ingot 0.002-20 part of (3), phosphorus 0.0001-1 part and aforementioned four kinds of materials can be gathered together enough 100 parts of surplus tin; Tin nickel intermediate alloy ingot, tin copper intermediate alloy ingot, tin indium intermediate alloy ingot and the surplus tin that takes by weighing is added in the stainless-steel pan, be warming up to 450 ℃ and carry out melting, carry out stirring in 30 minutes, uniform decrease in temperature slowly adds the phosphorus that weighs up and also continues to stir when temperature drops to 340 ℃ then;

(5) liquation that stirs is poured in the mould, be cast into the lead-free solder rod, obtain product of the present invention.

The present invention does wooden excellent whipping process Wheat Protein, and alloy appearance liquid leaves standstill and can make the alloy grain refinement in 30 minutes, improves the wetability of scolder; Add phosphorus effect be: can prevent that the oxidation piece from appearring in scolder, the flowability of scolder makes scruff obviously reduce simultaneously when improving weld job, and the brightness of solder joint increases.The indium that adds in this product is a tetragonal structure, and fusing point is very low, and reflective is good, good corrosion resistance.

Diffusion and wetability all improve to some extent; Through at 200 times of metallography microscope sem observations, find the crystalline phase even tissue, grain refinement.

Compare with prior art, the present invention has following advantage and effect:

Metallographic is more even, and more refinement has improved wetability, elongation, welding performance;

This product has good welding performance to wire rod, transformer, and easier and base material (Gu material) produces

Give birth to good affinity, the solder joint light, full.

The specific embodiment

Below in conjunction with embodiment the utility model is done further to specify, but content of the present invention is not limited to embodiment.

Because machine is same mutually for the fusing point of nickel, copper, tin, phosphorus and tin, wherein the fusing point of nickel, copper is higher for the fusing point in the smelting of balance tinbase, and is also this than the precious metal addition in order to prepare the more accurate grasp indium in scene, can adopt the method for producing intermediate alloy.Intermediate alloy and preparation method thereof is as follows:

Tin nickel intermediate alloy: the refined tin of stanniferous 99.95% added be warming up to 1600 ℃ after melting in the graphite crucible and add nickeliferous 99.95% smart nickel again, the mass ratio of its nickel consumption and tin is 2.5: 97.5, stirring with wooden stirring rod is smelted into the liquid tin nickel alloy, leaves standstill to cast nickeliferous 2.5% tin nickel intermediate alloy ingot after 30 minutes;

Tin copper intermediate alloy: be warming up to 1100 ℃ of smart copper that add cuprics 99.95% after melting in the refined tin adding graphite pincers crucible with stanniferous 99.95%, the mass ratio of its copper and tin is 10: 90, be smelted into the liquid tin copper alloy with wooden stirring, leave standstill the tin copper intermediate alloy ingot of casting cupric 10% after 30 minutes;

Tin indium intermediate alloy: the tin grain and the indium grain that contains indium 99.95% of stanniferous 99.95% are put in the Muffle furnace, and wherein the mass ratio of tin and indium is 95: 5, and smelting temperature is 350 ℃, be incubated 2 hours, stirred 30 minutes, left standstill 30 minutes, the tin indium intermediate alloy ingot that contains indium 5% is cast in the cooling of coming out of the stove.

After having prepared above-mentioned intermediate alloy, when making product of the present invention, can:

(1) takes by weighing in the following table 1# to the tin nickel intermediate alloy ingot of the given umber of 12# scheme, tin copper intermediate alloy ingot, tin indium intermediate alloy ingot, the refined tin of phosphorus and stanniferous 99.95% by quality.

(2) tin nickel intermediate alloy ingot, tin copper intermediate alloy ingot, tin indium intermediate alloy ingot and the surplus tin that takes by weighing is added in the stainless-steel pan, be warming up to 450 ℃ and carry out melting, carry out stirring in 30 minutes, uniform decrease in temperature slowly adds the phosphorus that weighs up and also continues to stir when temperature drops to 340 ℃ then;

(3) liquation that stirs is poured in the mould, be cast into the lead-free solder rod, obtain product of the present invention.

The component percentage composition table of the raw material mass mixture ratio of several prods and corresponding product thereof.

The embodiment numbering			1#	2#	3#	4	5#	6#
									The raw material mass fraction	Tin-nickel alloy		0.4	2	3.6	4.8	6	2.67
Gun-metal		0.33	1.67	3.33	5	6.67	3.33
								Tin-indium alloy		0.002	0.2	2	10	20	10
Phosphorus		0.0001	0.01	0.1	0.5	1	0.5
								Tin		99.2679	96.12	90.97	89.7	66.33	83.5
Product component (surplus tin)		Nickel	0.01	0.05	0.09	0.12	0.15									0.8
								Copper	0.1	0.5	1	1.5	2	1
		Indium	0.0001	0.01	0.1	0.5	1								0.5
								Phosphorus	0.0001	0.01	0.1	0.5	1	0.5

The embodiment numbering			7#	8#	9#	10#	11#	12#
									The raw material mass fraction	Tin-nickel alloy		6	4.8	2	0.4	13.33	20
Gun-metal		0.33	1.67	5	6.67	5	6.67
								Tin-indium alloy		0.002	0.2	10	20	20	10
Phosphorus		1	0.5	0.01	0.0001	1	0.5
								Tin		92.668	92.83	82.99	92.9299	60.67	62.83
Product component (surplus tin)		Nickel	0.15	0.12	0.05	0.01	4									6
								Copper	0.1	0.5	1.5	2	1.5	2
		Indium	0.0001	0.01	0.5	1	1								0.5
								Phosphorus	1	0.5	0.01	0.0001	1	0.5

Claims (2)

1. a lead-free solder is characterized in that, the constituent mass percentage of this scolder is: nickel 0.01-0.15%, and copper 0.1-2%, indium 0.0001-1%, phosphorus 0.0001-1%, surplus is a tin;

The preparation method of this scolder is as follows:

(1) refined tin of stanniferous 99.95% is added is warming up to 1600 ℃ after melting in the graphite crucible and adds nickeliferous 99.95% smart nickel again, the mass ratio of its nickel consumption and tin is 2.5: 97.5, stirring with wooden stirring rod is smelted into the liquid tin nickel alloy, leaves standstill to cast nickeliferous 2.5% tin nickel intermediate alloy ingot after 30 minutes;

(2) refined tin of stanniferous 99.95% is added be warming up to 1100 ℃ of smart copper that add cuprics 99.95% after melting in the graphite pincers crucible, the mass ratio of its copper and tin is 10: 90, be smelted into the liquid tin copper alloy with wooden stirring, leave standstill the tin copper intermediate alloy ingot of casting cupric 10% after 30 minutes;

(3) the tin grain with stanniferous 99.95% is put in the Muffle furnace with the indium grain that contains indium 99.95%, and wherein the mass ratio of tin and indium is 95: 5, and smelting temperature is 350 ℃, be incubated 2 hours, stirred 30 minutes, left standstill 30 minutes, the tin indium intermediate alloy ingot that contains indium 5% is cast in the cooling of coming out of the stove;

(4) take by weighing the tin nickel intermediate alloy ingot 0.4-6 part of (1) by quality, the tin copper intermediate alloy ingot 1-20 part of (2), the tin indium intermediate alloy ingot 0.002-20 part of (3), phosphorus 0.0001-1 part and aforementioned four kinds of materials can be gathered together enough 100 parts of surplus tin; Tin nickel intermediate alloy ingot, tin copper intermediate alloy ingot, tin indium intermediate alloy ingot and the surplus tin that takes by weighing is added in the stainless-steel pan, be warming up to 450 ℃ and carry out melting, carry out stirring in 30 minutes, uniform decrease in temperature slowly adds the phosphorus that weighs up and also continues to stir when temperature drops to 340 ℃ then;

(5) liquation that stirs is poured in the mould, be cast into the lead-free solder rod, obtain product of the present invention.

2. lead-free solder according to claim 1 is characterised in that the mass percent of its component is: nickel 0.8-4%, copper 0.5-1.5%, indium 0.1-1%, phosphorus 0.1-1%.