US5508561A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for forming a double-bump structure used for flip-chip mounting
Assignee: NEC Corp
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Filing: 1994-11-14
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Granted: 1996-04-16
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Expires: 2014-11-14
Abstract
Abstract A bump structure has a bump constituted by a metal projection which is formed on an electrode of a substrate, and a solder which covers the metal projection but does not touch the electrode. The metal projection is substantially spherical and has a projected portion at a center portion on an upper surface thereof. The metal projection is made of a metal having properties of solder diffusion prevention and adhesion to solder. The bump structure may have two bumps, the first bump being substantially the same as the bump described above and the second being such that its diameter is smaller than an outer diameter of the first bump and it covers the projected portion on the first bump. This bump structure can be formed using a simple process, and can be applied to flip-chip mounting in semiconductor devices with high reliability and yield.
Inventors
- 👤 Masamoto Tago
- 👤 Kei Tanaka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 09:15
CPC Classifications
H; H10; H10W; H10W72/00; H10W72/20; H10W72/01; H10W72/012; H10W72/01215; H10W72/01221; H10W72/01225; H10W72/01251; H10W72/01255; H10W72/071; H10W72/072; H10W72/07231; H10W72/07236; H10W72/241; H10W72/251; H10W72/252; H10W72/255; H10W72/50; H10W72/551; H10W72/552; H10W72/5522
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
117 words
A bump structure comprising: a first bump made of a conductive material, a first surface of which is fixed to an electrode of a substrate, and which is substantially spherical and has a projected portion at a center portion on a second surface thereof; said second surface being on the opposite side of said first bump from said first surface; and a second bump made of a conductive material having a diameter less than that of said first bump, and covering said projected portion on said first bump, but not touching said electrode; said first bump being made of a metal having properties of preventing said second bump from diffusing and of adhering to said second bump.
Claim 2
Dependent Claim
117 words
A bump structure comprising: a first bump made of a conductive material, a first surface of which is fixed to an electrode of a substrate, and which is substantially spherical and has a projected portion at a center portion on a second surface thereof; said second surface being on the opposite side of said first bump from said first surface; and a second bump made of a conductive material having a diameter less than that of said first bump, and covering said projected portion on said first bump, but not touching said electrode; said first bump being made of a metal having properties of preventing said second bump from diffusing and of adhering to said second bump.
Claim 3
Dependent Claim
26 words
The bump structure according to claim 1, in which said first bump has a cylindrical projected portion at the center portion on the second surface thereof.
Claim 4
Dependent Claim
26 words
The bump structure according to claim 1, in which said first bump has a conical projected portion at the center portion on the second surface thereof.
Claim 5
Dependent Claim
32 words
The bump structure according to claim 1, in which said first bump is made of a material selected from the group consisting of copper and a metal whose main composition is copper.
Claim 6
Dependent Claim
32 words
The bump structure according to claim 1, in which said first bump is made of a material selected from the group consisting of palladium and a metal whose main composition is palladium.
Claim 7
Dependent Claim
24 words
The bump structure according to claim 1, in which said second bump has a diameter smaller than an outer diameter of said first bump.
Claim 8
Dependent Claim
100 words
A bump structure comprising: a first bump made of a conductive material, a first surface of which is fixed to an electrode of a substrate, and which is substantially spherical and has a projected portion at a center portion on a second surface thereof; said second surface being on the opposite side of said first bump from said first surface; and a second bump made of a conductive material, and covering said projected portion on said first bump, but not touching said electrode; wherein said second bump has the diameter which is 40%-80% of the diameter of said first bump.
Claim 9
Dependent Claim
100 words
A bump structure comprising: a first bump made of a conductive material, a first surface of which is fixed to an electrode of a substrate, and which is substantially spherical and has a projected portion at a center portion on a second surface thereof; said second surface being on the opposite side of said first bump from said first surface; and a second bump made of a conductive material, and covering said projected portion on said first bump, but not touching said electrode; wherein said second bump has the diameter which is 40%-80% of the diameter of said first bump.
Claim 10
Dependent Claim
16 words
The bump structure according to claim 1, in which said second bump is made of solder.
Claim 11
Dependent Claim
18 words
The bump structure according to claim 1, in which said second bump is made of conductive resin material.
Claim 12
Dependent Claim
25 words
The bump structure according to claim 1, in which said electrode is made of one of an aluminum electrode and an aluminum compound metal electrode.
Claim 13
Dependent Claim
15 words
The bump structure according to claim 1, in which said substrate is a semiconductor chip.
Claim 14
Dependent Claim
127 words
A flip-chip connecting structure comprising: a first bump made of a conductive material, a first surface of which is fixed to a first electrode of a first substrate, and which is substantially spherical and has a projected portion at a center portion on a second surface thereof, said second surface being on the opposite side of said first bump from said first surface; and a second bump made of a conductive material having a diameter less than that of said first bump, and being configured such that it interconnects said second electrode and said first bump but does not touch said first electrode; said first bump being made of a metal having properties of preventing said second bump from diffusing and of adhering to said second bump.
Claim 15
Dependent Claim
127 words
A flip-chip connecting structure comprising: a first bump made of a conductive material, a first surface of which is fixed to a first electrode of a first substrate, and which is substantially spherical and has a projected portion at a center portion on a second surface thereof, said second surface being on the opposite side of said first bump from said first surface; and a second bump made of a conductive material having a diameter less than that of said first bump, and being configured such that it interconnects said second electrode and said first bump but does not touch said first electrode; said first bump being made of a metal having properties of preventing said second bump from diffusing and of adhering to said second bump.
Claim 16
Dependent Claim
27 words
The flip-chip connecting structure according to claim 12, in which said first bump has a cylindrical projected portion at the center portion on the second surface thereof.
Claim 17
Dependent Claim
27 words
The flip-chip connecting structure according to claim 12, in which said first bump has a conical projected portion at the center portion on the second surface thereof.
Claim 18
Dependent Claim
33 words
The flip-chip connecting structure according to claim 12, in which said first bump is made of a material selected from the group consisting of copper and a metal whose main composition is copper.
Claim 19
Dependent Claim
33 words
The flip-chip connecting structure according to claim 12, in which said first bump is made of a material selected from the group consisting of palladium and a metal whose main composition is palladium.
Claim 20
Dependent Claim
25 words
The flip-chip connecting structure according to claim 12, in which said second bump has a diameter smaller than an outer diameter of said first bump.
Claim 21
Dependent Claim
110 words
A flip-chip connecting structure comprising: a first bump made of a conductive material, a first surface of which is fixed to a first electrode of a first substrate, and which is substantially spherical and has a projected portion at a center portion on a second surface thereof, said second surface being on the opposite side of said first bump from said first surface; and a second bump made of a conductive material, and being configured such that it interconnects said second electrode and said first bump but does not touch said first electrode; wherein said second bump has the diameter which is 40%-80% of the diameter of said first bump.
Claim 22
Dependent Claim
110 words
A flip-chip connecting structure comprising: a first bump made of a conductive material, a first surface of which is fixed to a first electrode of a first substrate, and which is substantially spherical and has a projected portion at a center portion on a second surface thereof, said second surface being on the opposite side of said first bump from said first surface; and a second bump made of a conductive material, and being configured such that it interconnects said second electrode and said first bump but does not touch said first electrode; wherein said second bump has the diameter which is 40%-80% of the diameter of said first bump.
Claim 23
Dependent Claim
17 words
The flip-chip connecting structure according to claim 12, in which said second bump is made of solder.
Claim 24
Dependent Claim
19 words
The flip-chip connecting structure according to claim 12, in which said second bump is made of conductive resin material.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1999-04-16 | 1999-10-16 | 2000-04-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-04-16 | 2003-10-16 | 2004-04-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-04-16 | 2007-10-16 | 2008-04-16 | $7700.00 | Window Closed / Lapsed |