CN106031963A

CN106031963A - A lead-free and silver-free tin bar and a preparation method thereof

Info

Publication number: CN106031963A
Application number: CN201510106132.7A
Authority: CN
Inventors: 李姗; 龙斌; 魏河; 柴庆文; 苏秋华; 张春慧; 梁小伟; 林展羽; 罗星; 李佐杰; 王灵芝; 李义成; 伍玉
Original assignee: ZHONGSHAN TIN-KING Co Ltd
Current assignee: ZHONGSHAN TIN-KING Co Ltd
Priority date: 2015-03-11
Filing date: 2015-03-11
Publication date: 2016-10-19

Abstract

The invention provides a lead-free and silver-free tin bar and a preparation method thereof. The tin bar contains 0.001-2.2wt% of cobalt, 0.45-0.55wt% of copper, 0-0.2wt% of nickel, 7.0-9.0wt% of bismuth, 0-0.3wt% of phosphor, and 0-0.01wt% of germanium, the rest being tin. The brazing filler in the invention contains no lead and silver and employs cobalt (Co) and bismuth (Bi) alloy, so that the hardness of welding spots is improved and the problem of brittleness thereof is solved while the melting point temperature of the soldering tin bar is reduced to 186-217 and the welding temperature is reduced to 196-227; with the low melting point, when components pass through wave soldering, the fracture phenomena of the components are greatly reduced; during soldering, soldering tine alloy oxidation is prevented, and generation of solder splash scraps is restrained and solder splash is reduced; while the favorable soldering performance of lead-free soldering tin bar alloy is guaranteed, the production cost of enterprises is greatly reduced, so that the tin bar is of great economic benefit.

Description

A kind of unleaded without silver tin bar and preparation method thereof

[technical field]

The invention belongs to alloy conductive field of material technology, be specifically related to a kind of unleaded without silver tin bar And preparation method thereof.

[background technology]

Conventional leypewter solder, because lead and compound thereof are to the harm of human body with to environment Pollute, by the multinational legislation in world disabling, replaced by lead-free tin bar, use the weldering of environment-friendly type Tin material has become industrial trend.But during lead-free brazing uses at present, a technical problem underlying Solder fusing point and welding procedure temperature drift, and add other materials make high expensive, The use making many electronic devices and components and material faces the select permeability of cost and material.

Current Sn-Ag (comprising Sn-Ag-Cu) series, as Sn3.5Ag0.3, Sn95.5Ag4.0Cu0.5, Sn99.2Ag0.1Cu0.7 etc., its minimum fusing point still has About 220 DEG C, all it is difficult to the low-temperature phase ratio with SnPb solder, and the holding at high price of silver, give Production cost brings immense pressure, also has addition bismuth metal, in order to reduce weld point temperature, but SnBi Alloy physics character is the most crisp to be difficult to, and said ratio solder scruff amount is on the high side, cost of idleness, What after welding, components and parts ruptured is on the high side, and welding quality is difficult to ensure that.

[summary of the invention]

It is an object of the invention to overcome the deficiencies in the prior art, it is provided that a kind of fusing point is relatively low, to ring Border is pollution-free, the unleaded soldering tin bar without silver, little to electronic devices and components heat affecting during welding, reduces The generation of scruff, that improves that welding component ruptures is bad, saves the cost of raw material.

Technical solution of the present invention is as follows:

A kind of unleaded tin bar without silver soldering, it is characterised in that: containing the cobalt of 0.001～2.2wt%, The copper of 0.45～0.55wt%, the nickel of 0～0.2wt%, the bismuth of 7.0～9.0wt%, 0～0.3wt% Phosphorus, the germanium of 0～0.01wt%, remaining is stannum.

The unleaded tin bar without silver soldering of one of the present invention, it is characterised in that possibly together with 0.005～ 0.15wt% nickel, 0.2～0.25wt% phosphorus and 0.006～0.01wt% germanium in one or more.

The unleaded tin bar without silver soldering of one of the present invention, it is characterised in that containing 0.18～2.2wt% Cobalt, the copper of 0.45～0.55wt%, the nickel of 0.005～0.15wt%, the bismuth of 7.0～8.8wt%, The phosphorus of 0.2～0.25wt%, remaining is stannum.

The unleaded tin bar without silver soldering of one of the present invention, it is characterised in that containing the cobalt of 1.8wt%, The copper of 0.49wt%, the bismuth of 7.8wt%, the phosphorus of 0.23wt%, remaining is stannum.

The unleaded tin bar without silver soldering of one of the present invention, it is characterised in that containing 1.5～2.1wt% Cobalt, the copper of 0.45～0.51wt%, the bismuth of 8.0～8.8wt%, the phosphorus of 0～0.25wt%, 0.1～0.18 The nickel of wt%, remaining is stannum.

The unleaded tin bar without silver soldering of one of the present invention, it is characterised in that containing the cobalt of 2.1wt%, The copper of 0.51wt%, the nickel of 0.18wt%, the bismuth of 8.8wt%, remaining is stannum.

The preparation method of a kind of above-mentioned unleaded tin bar without silver soldering, it is characterised in that include following Step:

First stannum is melted to 390-400 DEG C, insulated and stirred 20-25min, pull out after having stirred Scruff, add bismuth continue stirring 10-15min, add phosphorus stirring 10-15min, add copper, cobalt, Nickel stirring 10-15min, adds germanium stirring 2-3min, and it is qualified that sampling detects above composition, cooling Start to shape a kind of unleaded tin bar without silver soldering of middle temperature to about 300-340 DEG C.

The present invention, relative to prior art, has the advantage that

In the solder of the present invention, unleaded nothing silver, uses cobalt (Co) and bismuth (Bi) alloy, reduces Soldering tin bar melting temperature to 186～217 and welding temperature to while 196～227, improve weldering The hardness of point, improves its brittle problem, and fusing point is low, and element is through wave-soldering, unit's device Part fracture phenomena reduces in a large number, and can prevent and treat soldering alloy oxidation when welding, and suppression scruff is broken The generation of bits, decreases scruff, in the good welds performance basis ensureing Pb-free coating tin bar alloy On, greatly reduce enterprise's production cost, there is good economic benefit.

[detailed description of the invention]

Below in conjunction with specific embodiment, the invention will be further described:

Embodiment 1:

A kind of unleaded without silver tin bar, by weight percentage, its formula consists of:

Preparation method: first stannum is melted to 400 DEG C, insulated and stirred 25min, drag for after having stirred Go out scruff, add bismuth and continue stirring 10min, add phosphorus stirring 10min, add copper, cobalt, nickel Stirring 10-15min, adds germanium stirring 2-3min, and it is qualified that sampling detects above composition, is cooled to About 340 DEG C start to shape a kind of unleaded nothing silver tin bar.

Embodiment 2:

Preparation method: first stannum is melted to 400 DEG C, insulated and stirred 25min, drag for after having stirred Go out scruff, add bismuth and continue stirring 10min, add phosphorus stirring 10min, add copper, cobalt stirring 10-15min, adds germanium stirring 2-3min, and it is qualified that sampling detects above composition, is cooled to 340 DEG C Left and right starts to shape a kind of unleaded nothing silver tin bar.

Embodiment 3:

Preparation method: first stannum is melted to 400 DEG C, insulated and stirred 25min, drag for after having stirred Go out scruff, add bismuth and continue stirring 15min, add phosphorus stirring 10min, add copper, cobalt, nickel Stirring 10-15min, adds germanium stirring 2-3min, and it is qualified that sampling detects above composition, is cooled to About 340 DEG C start to shape a kind of unleaded nothing silver tin bar.

Embodiment 4:

Preparation method: first stannum is melted to 390 DEG C, insulated and stirred 20min, drag for after having stirred Go out scruff, add bismuth and continue stirring 15min, add phosphorus stirring 15min, add copper, cobalt, nickel Stirring 15min, adds germanium stirring 2min, and it is qualified that sampling detects above composition, is cooled to 300 DEG C Left and right starts to shape a kind of unleaded nothing silver tin bar.

Embodiment 5-11:

Unleaded without silver tin bar, by weight percentage, its formula composition is as follows:

The preparation method of embodiment 5-11 is:

First stannum is melted to 390-400 DEG C, insulated and stirred 20-25min, pull out after having stirred Scruff, adds bismuth and continues stirring 10-15min, adds phosphorus stirring 10-15min, adds copper, cobalt And/or nickel stirring 10-15min, or add germanium stirring 2-3min, it is qualified that sampling detects above composition, It is cooled to about 300-340 DEG C start to shape a kind of unleaded tin bar without silver soldering of middle temperature.

Embodiment 1-11 is as shown in table 1 with the testing result of comparative example:

Table 1: temperature measuring (solidus more than 175, liquidus curve more than 184):

Table 2: client uses temperature comparisons's (use temperature close to 245 DEG C):

Table 3: client produces scruff amount and contrasts (scruff amount is less than 3) after using:

Table 4: after client uses, components and parts rupture contrast (in 8H fraction defective less than 32):

By above test result: employ without silver joining containing cobalt (Co) and bismuth (Bi) Side, it is possible to decrease the temperature of Pb-free solder material, reduces the temperature of solder joint during client uses, protects Electronic devices and components, in suppression Pb-free solder material use, the generation of scruff, is substantially reduced components and parts weldering The generation ruptured after connecing.

Claims

1. a unleaded tin bar without silver soldering, it is characterised in that: containing the cobalt of 0.001～2.2wt%, The copper of 0.45～0.55wt%, the nickel of 0～0.2wt%, the bismuth of 7.0～9.0wt%, 0～0.3wt% Phosphorus, the germanium of 0～0.01wt%, remaining is stannum.

The unleaded tin bar without silver soldering of one the most according to claim 1, it is characterised in that also Containing 0.005～0.15wt% nickel, 0.2～0.25wt% phosphorus and 0.006～0.01wt% germanium in One or more.

The unleaded tin bar without silver soldering of one the most according to claim 2, it is characterised in that contain There is a cobalt of 0.18～2.2wt%, the copper of 0.45～0.55wt%, the nickel of 0.005～0.15wt%, The bismuth of 7.0～8.8wt%, the phosphorus of 0.2～0.25wt%, remaining is stannum.

The unleaded tin bar without silver soldering of one the most according to claim 2, it is characterised in that contain Having the cobalt of 1.8wt%, the copper of 0.49wt%, the bismuth of 7.8wt%, the phosphorus of 0.23wt%, remaining is stannum.

The unleaded tin bar without silver soldering of one the most according to claim 2, it is characterised in that contain Have a cobalt of 1.5～2.1wt%, the copper of 0.45～0.51wt%, the bismuth of 8.0～8.8wt%, 0～ The phosphorus of 0.25wt%, the nickel of 0.1～0.18wt%, remaining is stannum.

The unleaded tin bar without silver soldering of one the most according to claim 2, it is characterised in that contain The cobalt of 2.1wt%, the copper of 0.51wt%, the nickel of 0.18wt%, the bismuth of 8.8wt%, remaining is stannum.

7. a preparation method for any one unleaded tin bar without silver soldering in claim 1-7, its It is characterised by comprising the following steps:

First stannum is melted to 390-400 DEG C, insulated and stirred 20-25min, drag for after having stirred Go out scruff, add bismuth and continue stirring 10-15min, add phosphorus stirring 10-15min, add copper, Cobalt, nickel stirring 10-15min, adds germanium stirring 2-3min, and it is qualified that sampling detects above composition, It is cooled to 300-340 DEG C start to shape a kind of middle temperature Pb-free coating tin bar.