EP0622151A1
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EP
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An Article comprising a pb-free solder having improved mechanical properties
Assignee: AT&T Inc
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Filing: 1994-04-20
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Granted: —
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Expires: 2014-04-20
Abstract
Abstract A Pb-free solder alloy, based on the Sn-In-Zn system (exemplarily 86:5:9 weight %), is disclosed. Composition can have a melting temperature in the range 183°C ± 10°C and thus can be readily substituted for conventional 40 Pb - 60 Sn solder. The novel composition also can possess superior mechanical properties, compared to the 40/60 Pb-Sn composition, and readily wets copper.
Inventors
- 👤 Ho Sou Chen
- 👤 Sungho Jin
- 👤 Mark Thomas Mccormack
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-01 20:04
CPC Classifications
C; C22; C22C; C22C13/00; B; B23; B23K; B23K35/00; B23K35/22; B23K35/24; B23K35/26; B23K35/262
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
71 words
An article comprising an essentially Pb-free solder composition comprising at least 70 weight % tin (Sn) and between 3 and 15 weight % zinc (Zn); associated with the composition being a melting temperature; Characterized In That the composition further comprises an amount of indium (In) effective for imparting to the composition a melting temperature that is at least 5°C lower than the melting temperature of an, otherwise identical, In-free comparison composition.
Claim 2
Dependent Claim
45 words
An article according to claim 1, the composition comprising at least 80 weight % Sn, 6-10 weight % Zn, 3-10 weight % In, with the amount of In furthermore selected such that the melting temperature of the composition is in the range 183°C ± 10°C.
Claim 3
Dependent Claim
16 words
An article according to claim 2, wherein the composition consists essentially of Sn, Zn and In.
Claim 4
Dependent Claim
30 words
An article according to claim 2, wherein the composition comprises one or both of Bi and Sb in an individual amount of at most 10 and 5 weight %, respectively.
Claim 5
Dependent Claim
73 words
An article according to claim 2, wherein the composition further comprises at least one element of the group consisting of Bi, Sb, Cu, Ag and Au, with Bi being present in an amount of at most 10 weight %, and the other elements of the group being present in individual amount of at most 5 weight %, and with the total amount of elements of the group being at most 15 weight %.
Claim 6
Dependent Claim
59 words
An article according to claim 2, wherein associated with the composition is a room temperature ultimate tensile strength (UTS), a room temperature 0.2% offset yield strength (YS), and a creep strain at 100°C, and wherein one or both of UTS and YS are at least 10% larger than the UTS and YS of a 40/60 weight % Pb-Sn composition.
Claim 7
Dependent Claim
24 words
An article according to claim 6, wherein furthermore said creep strain is at most 50% of the corresponding creep strain of said Pb-Sn composition.
Claim 8
Dependent Claim
55 words
An article according to claim 2, wherein associated with the composition is a wetting force at 245°C in air on copper, and wherein maximum wetting force is attained in a time less than 2 seconds and is at least 50% of the maximum wetting force attained under the same conditions with 40/60 weight % Pb-Sn.
Claim 9
Dependent Claim
19 words
An article according to claim 1, wherein the article is a solder paste, cream, preform, wire, ribbon or bar.
References Cited (Backward Citations)
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