US5307983A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making an article comprising solder bump bonding
Assignee: Agere Systems LLC
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Filing: 1993-04-27
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Granted: 1994-05-03
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Expires: 2013-04-27
Abstract
Abstract The present invention is embodied in a technique for precise and accurate height control in fabricating solder bumps or joints formed from a solder bump or bumps. A solder bump is formed by reflow of a conical solder body having base diameter D, height H and cone angle θ, and has truncated sphere shape, with height h and truncation diameter d. We have found that D, H, and d can be selected such that ∂h/∂H is small (typically ≦0.5), indicative of relative insensitivity of the bump height to variation in the height of the conical solder body. The inventive process is also applicable to a component (e.g., a laser) solder-bonded to a substrate, and can provide previously unattainable control of the spacing between component and substrate.
Inventors
- 👤 Thomas D. Dudderar
- 👤 Chee C. Wong
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 22:14
CPC Classifications
H; H10; H10W; H10W72/00; H10W72/01; H10W72/012; H05; H05K; H05K3/00; H05K3/30; H05K3/32; H05K3/34; H05K3/341; H05K3/3431; H05K3/3465; H10W72/01231; H10W72/01238; H10W72/20; H10W72/251; H10W72/90; H10W72/951; H10W72/952
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
229 words
Method of making an article that comprises a first body attached to a second body (to be referred to as the "substrate") by means that comprise reflowable material (to be referred to as "solder"), the method comprising: a) providing the substrate having a major surface that comprises at least one circular region of a first material that is wettable by the solder, said first material region being surrounded by a second material that is substantially not wettable by the solder, said first material region having diameter d; b) forming on said first material region a substantially conical solder body associated with said solder body being a base of diameter D, a side wall, a conical height H and an angle θ (to be referred to as the "cone angle") between said base and said side wall; c) causing said conical solder body to melt forming a molten material; d) causing said molten material to re-solidify, such that a resolidified solder body (to be referred to as the first solder bump) results, said first solder bump having a truncated sphere shape, of height h, and truncation diameter d; and e) attaching the first body to the substrate by a process that comprises melting said solder bump; Characterized In That f) H, D, d and θ are selected such that a demagnification factor ∂h/∂H, is less than or equal to 0.5.
Claim 2
Dependent Claim
229 words
Method of making an article that comprises a first body attached to a second body (to be referred to as the "substrate") by means that comprise reflowable material (to be referred to as "solder"), the method comprising: a) providing the substrate having a major surface that comprises at least one circular region of a first material that is wettable by the solder, said first material region being surrounded by a second material that is substantially not wettable by the solder, said first material region having diameter d; b) forming on said first material region a substantially conical solder body associated with said solder body being a base of diameter D, a side wall, a conical height H and an angle θ (to be referred to as the "cone angle") between said base and said side wall; c) causing said conical solder body to melt forming a molten material; d) causing said molten material to re-solidify, such that a resolidified solder body (to be referred to as the first solder bump) results, said first solder bump having a truncated sphere shape, of height h, and truncation diameter d; and e) attaching the first body to the substrate by a process that comprises melting said solder bump; Characterized In That f) H, D, d and θ are selected such that a demagnification factor ∂h/∂H, is less than or equal to 0.5.
Claim 3
Dependent Claim
26 words
A method according to claim 1, comprising forming said conical solder body by a process that comprises line-of-sight deposition through an aperture in a liftoff mask.
Claim 4
Dependent Claim
30 words
A method according to claim 1, wherein said first body comprises at least one circular region, of diameter d 2 , of a material that is wettable by the solder.
Claim 5
Dependent Claim
126 words
A method according to claim 3, further comprising the steps of a) forming on the circular region of said first body a second conical solder body having a base of diameter D', a side wall, a conical height H' and a cone angle θ' between said base and said side wall; b) causing said second conical solder body to melt forming a molten material; c) causing said molten material to re-solidify such that a second resolidified solder body (to be referred to as the second solder bump) results, said second solder bump having a truncated sphere shape of height h', and truncation diameter d'; wherein d) H', D', d' and θ' are selected such that a demagnification factor ∂h'/∂H' is less than or equal to 0.5.
Claim 6
Dependent Claim
44 words
A method according to claim 4, wherein attaching the first body to the substrate comprises: a) bringing said first solder bump into contact with said second solder bump; b) melting said first and second solder bumps; and c) allowing the melted solder to solidify.
Claim 7
Dependent Claim
45 words
A method according to claim 3, wherein attaching the first body to the substrate comprises: a) bringing said first solder bump into contact with said circular region of said first body; b) melting said first solder bump; and c) allowing the melted material to solidify.
Claim 8
Dependent Claim
13 words
Method according to claim 1, wherein the first body is a semiconductor laser.
Claim 9
Independent Claim
167 words
A method of making an article that comprises a substrate with a solder bump thereon, the method comprising: a) providing the substrate having a major surface that comprises at least one circular region of a first material that is wettable by a solder, said first material region being surrounded by a second material that is substantially not wettable by the solder, said first material region having diameter d; b) forming on said first material region a substantially conical solder body having a base of diameter D, a side wall, a conical height H and an angle θ between said base and said side wall; c) causing said conical solder body to melt forming molten solder; d) causing said molten solder to re-solidify, such that the solder bump results, said solder bump having a truncated sphere shape, of height h, and truncation diameter d; Characterized In That e) H, D, d and θ are selected such that a demagnification factor ∂h/∂H is less than or equal to 0.5.
Claim 10
Independent Claim
167 words
A method of making an article that comprises a substrate with a solder bump thereon, the method comprising: a) providing the substrate having a major surface that comprises at least one circular region of a first material that is wettable by a solder, said first material region being surrounded by a second material that is substantially not wettable by the solder, said first material region having diameter d; b) forming on said first material region a substantially conical solder body having a base of diameter D, a side wall, a conical height H and an angle θ between said base and said side wall; c) causing said conical solder body to melt forming molten solder; d) causing said molten solder to re-solidify, such that the solder bump results, said solder bump having a truncated sphere shape, of height h, and truncation diameter d; Characterized In That e) H, D, d and θ are selected such that a demagnification factor ∂h/∂H is less than or equal to 0.5.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-05-02 | 1997-11-01 | 1998-05-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-05-02 | 2001-11-01 | 2002-05-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-05-02 | 2005-11-01 | 2006-05-03 | $7700.00 | Window Closed / Lapsed |