CN1234498C

CN1234498C - Lead-free solder

Info

Publication number: CN1234498C
Application number: CN02129643.XA
Authority: CN
Inventors: 薛松柏; 廖高兵
Original assignee: Individual
Current assignee: Shenzhen Vital New Material Compangy Ltd
Priority date: 2002-09-06
Filing date: 2002-09-06
Publication date: 2006-01-04
Anticipated expiration: 2022-09-06
Also published as: CN1398696A

Abstract

The present invention provides lead-free solder which relates to an alloy, particularly to a lead-free solder alloy. Although some properties of a Sn-Ag-Cu three-element lead-free alloy are close to that of a Sn-Pb alloy, the three-element lead-free alloy sills has some defects of bad spreading performance and gap filling performance on the surfaces of metal including Cu, etc., large wetting angle theta and high melting point. The lead-free solder comprises stannum, argentum and cuprum, wherein micro plumbum and optional kind of lanthanum or cerium is added into the stannum, the argentum and the cuprum; the lead-free solder comprise, in weight percentages, 94.7 to 98% of stannum, 1 to 3.5% of argentum, 0.5 to 1.5% of cuprum, 0.01 to 0.2% of plumbum and 0.001 to 0.1% of lanthanum or cerium. The lead-free solder can be used for soldering electronic components or connecting corresponding products of other industry to obviously improve the soldering performance.

Description

Lead-free brazing

Technical field: the present invention relates to a kind of alloy, particularly a kind of unleaded brazing alloy.

Background technology: lead is nondegradable toxic metals element, is again the metal of industrial a large amount of uses at present.Along with the pay attention to day by day of countries in the world to environmental protection, the plumbous application of numerous and confused legislation restriction.The research and development of no lead solders (being lead-free brazing) and application more and more come into one's own, and up to the present, the lead-free brazing of researching and developing out both at home and abroad has the hundreds of kind, comprising the tin-silver-copper alloy.Though near tin-lead alloy, but still there are many deficiencies in tin-silver-copper ternary lead-free alloy on many performances.At first, stannum-silver-copper three-part alloy is relatively poor at spreading property, the gap filling performance of metal surfaces such as copper, angle of wetting θ is bigger, fusing point is higher, and (as the Sn40Pb60 alloy melting point is 183 ℃, and the tin-silver-copper alloy melting point is 220 ℃), therefore, the application of not only above-mentioned tin-silver-copper lead-free alloy has been subjected to considerable restraint, and demand of practical production also urgently looks forward to developing early the lead-free brazing that can really satisfy instructions for use.

Summary of the invention: the object of the present invention is to provide a kind of brazing property is significantly improved, combination property reaches or near the lead-free brazing of traditional Sn40Pb60 solder containing lead alloy property level.Its objective is such realization: lead-free brazing comprises tin, silver, copper, in tin, silver, copper, add a kind of in plumbous and the optional lanthanum or the cerium of trace, by mass, tin accounts for 94.7～98%, silver accounts for 1～3.5%, copper accounts for 0.5～1.5%, lead accounts for 0.01～0.2%, lanthanum or cerium account for 0.001～0.03%; The lead, lanthanum and the cerium that perhaps add trace in tin, silver, copper, by mass, tin accounts for 94.7～98%, silver accounts for 1～3.5%, copper accounts for 0.5～1.5%, lead accounts for 0.01～0.2%, lanthanum accounts for 0.001～0.03%, cerium accounts for 0.001～0.03%.The invention has the advantages that: pure tin can be wetting well on the surface of copper, but spreading property is not good, hinders flowing of tin; Adding does not produce the also difficult lead that dissolves each other of compound with copper, has diluted tin, has weakened the generation of compound, thereby spreading property is improved greatly.This invention is exactly in the tin-silver-copper alloy, treats as a kind of useful alloying element plumbous, promptly has a mind to add a spot of lead in unleaded fully alloy, to improve the spreading property of kamash alloy.And a spot of lead (0.01～0.02%) had both met the limited field of states such as the U.S., European Union and Japan to lead, satisfied " unleaded " on the technical meaning, and promptly Qian content is not more than 0.2%, has significantly improved the spreading property of tin-silver-copper alloy again; The adding of trace lanthanum and/or cerium has reduced brazing filler metal alloy on the one hand at the angle of wetting θ on copper surface (having improved wettability), and the mechanical property of brazing filler metal alloy is increased.And the relevant data of measuring according to the regulation of GB/T11363-1989 standards such as " solder spreadability and clearance fillability test methods " shows, the spreading property of neoteric Xi-Yin-lead-copper-lanthanum (cerium) brazing filler metal alloy, angle of wetting θ and mechanical property all near in addition surpassed traditional tin-lead alloy.This alloy has good spreading property, wettability and mechanical property on the copper surface.

The specific embodiment one: the present invention can be used for the connection of the Related product of the soldering of electronic devices and components (printed circuit board (PCB), leads of electronic component etc.) or other industry and uses.Present embodiment comprises tin, silver, copper, in tin, silver, copper, add a kind of in plumbous and the optional lanthanum or the cerium of trace, by mass, tin accounts for 94.7～98%, silver accounts for 1～3.5%, copper accounts for 0.5～1.5%, lead accounts for 0.01～0.2%, lanthanum or cerium account for 0.001～0.03%.

The specific embodiment two: what present embodiment and the specific embodiment one were different is, by mass: tin accounts for 96.28%, and silver accounts for 2.8%, and copper accounts for 0.72%, and lead accounts for 0.18%, and lanthanum or cerium account for 0.02%.

The specific embodiment three: what present embodiment and the specific embodiment one, two were different is, by mass: tin accounts for 96.58%, and silver accounts for 2.6%, and copper accounts for 0.6%, and lead accounts for 0.20%, and lanthanum or cerium account for 0.02%.

The specific embodiment four: what present embodiment and the specific embodiment one, two, three were different is, by mass: tin accounts for 95.72%, and silver accounts for 3.3%, and copper accounts for 0.8%, and lead accounts for 0.15%, and lanthanum or cerium account for 0.03%.

The specific embodiment five: what present embodiment and the specific embodiment one, two, three, four were different is, the lead, lanthanum and the cerium that in tin, silver, copper, add trace, by mass, tin accounts for 94.7～98%, silver accounts for 1～3.5%, copper accounts for 0.5～1.5%, lead accounts for 0.01～0.2%, lanthanum accounts for 0.001～0.03%, cerium accounts for 0.001～0.03%.

The specific embodiment six: what present embodiment and the specific embodiment five were different is, by mass: tin accounts for 96.26%, and silver accounts for 2.8%, and copper accounts for 0.72%, and lead accounts for 0.18%, and lanthanum accounts for 0.02%, and cerium accounts for 0.02%.

The specific embodiment seven: what present embodiment and the specific embodiment five, six were different is, by mass: tin accounts for 96.58%, and silver accounts for 2.6%, and copper accounts for 0.6%, and lead accounts for 0.20%, and lanthanum accounts for 0.01%, and cerium accounts for 0.01%.

The specific embodiment eight: what present embodiment and the specific embodiment five, six, seven were different is, by mass: tin accounts for 95.72%, and silver accounts for 3.3%, and copper accounts for 0.8%, and lead accounts for 0.15%, and lanthanum accounts for 0.01%, and cerium accounts for 0.02%.

Claims

1, a kind of lead-free brazing, it comprises tin, silver, copper, it is characterized in that in tin, silver, copper adding a kind of in plumbous and the optional lanthanum or the cerium of trace, by mass, tin accounts for 94.7～98%, silver accounts for 1～3.5%, copper accounts for 0.5～1.5%, lead accounts for 0.01～0.2%, lanthanum or cerium account for 0.001～0.03%.

2, lead-free brazing according to claim 1 is characterized in that by mass: tin accounts for 96.28%, silver accounts for 2.8%, copper accounts for 0.72%, lead accounts for 0.18%, lanthanum or cerium account for 0.02%.

3, lead-free brazing according to claim 1 is characterized in that by mass: tin accounts for 96.58%, silver accounts for 2.6%, copper accounts for 0.6%, lead accounts for 0.20%, lanthanum or cerium account for 0.02%.

4, lead-free brazing according to claim 1 is characterized in that by mass: tin accounts for 95.72%, silver accounts for 3.3%, copper accounts for 0.8%, lead accounts for 0.15%, lanthanum or cerium account for 0.03%.

5, a kind of lead-free brazing, it comprises tin, silver, copper, it is characterized in that in tin, silver, copper, adding lead, lanthanum and the cerium of trace, by mass, tin accounts for 94.7～98%, silver accounts for 1～3.5%, copper accounts for 0.5～1.5%, lead accounts for 0.01～0.2%, lanthanum accounts for 0.001～0.03%, cerium accounts for 0.001～0.03%.

6, lead-free brazing according to claim 5 is characterized in that by mass: tin accounts for 96.26%, silver accounts for 2.8%, copper accounts for 0.72%, lead accounts for 0.18%, lanthanum accounts for 0.02%, cerium accounts for 0.02%.

7, lead-free brazing according to claim 5 is characterized in that by mass: tin accounts for 96.58%, silver accounts for 2.6%, copper accounts for 0.6%, lead accounts for 0.20%, lanthanum accounts for 0.01%, cerium accounts for 0.01%.

8, lead-free brazing according to claim 5 is characterized in that by mass: tin accounts for 95.72%, silver accounts for 3.3%, copper accounts for 0.8%, lead accounts for 0.15%, lanthanum accounts for 0.01%, cerium accounts for 0.02%.