US4855251A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of manufacturing electronic parts including transfer of bumps of larger particle sizes
Assignee: Toshiba Corp
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Filing: 1988-11-03
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Granted: 1989-08-08
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Expires: 2008-11-03
Abstract
Abstract According to the present invention, a method is provided of manufacturing electronic parts, comprising a first step of forming on the surface of a substrate a bump wherein the metal particles of that portion of the bump which contacts the surface of the substrate have a larger diameter than the metal particles of that portion of the bump which does not contact the surface of the substrate, a second step of transferring the bump to an electrode lead, and a third step of connecting an electrode lead to a predetermined electrode section of the semiconductor chip, by means of the transferred bump. The method of the present invention ensures that the bump does not fall off during the electroplating and washing steps, and ensures a high-strength bond between the transferred bump and the electrode section of a semiconductor chip.
Inventors
- 👤 Kiyoshi Iyogi
- 👤 Koji Yamakawa
- 👤 Nobuo Iwase
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 19:31
CPC Classifications
H; H10; H10W; H10W72/00; H10W72/20; H10W72/01; H10W72/012; H10W72/01204; H10W72/01212; H10W72/251; H10W72/252; H10W72/90; H10W72/951; H10W72/952; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49117; Y10T29/49121
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
98 words
A method of manufacturing electronic parts, comprising: a first step of forming on the surface of a substrate a bump with substantially all the metal crystal particles of that portion of the bump which contacts the surface of the substrate having larger diameters than the metal crystal particles of that portion of the bump which does not contact the surface of the substrate; a second step of transferring the bump to an electrode lead; and a third step of connecting an electrode lead to the predetermined electrode section of the semiconductor chip, by means of the transferred bump.
Claim 2
Independent Claim
98 words
A method of manufacturing electronic parts, comprising: a first step of forming on the surface of a substrate a bump with substantially all the metal crystal particles of that portion of the bump which contacts the surface of the substrate having larger diameters than the metal crystal particles of that portion of the bump which does not contact the surface of the substrate; a second step of transferring the bump to an electrode lead; and a third step of connecting an electrode lead to the predetermined electrode section of the semiconductor chip, by means of the transferred bump.
Claim 3
Dependent Claim
28 words
The method according to claim 1, wherein the metal crystal particles of that portion of the bump which contacts the substrate have a diameter larger than 1 μm.
Claim 4
Dependent Claim
13 words
The method according to claim 1, wherein the bump is formed by electroplating.
Claim 5
Dependent Claim
33 words
The method according to claim 3, wherein the initial current density of electroplating applied to the formation of a bump is defined to be 2-5 times the current density which is used thereafter.
Claim 6
Dependent Claim
15 words
The method according to claim 1, wherein the bump has a thickness of 15-25 μm.
Claim 7
Dependent Claim
15 words
The method according to claim 1, wherein the bump is prepared from gold or copper.
Claim 8
Dependent Claim
34 words
The method according to claim 1, wherein the substrate on which the bump is to be formed is constructed by laminating a conductive layer and conductive oxide layer, in that order, on the basesubstrate.
Claim 9
Dependent Claim
25 words
The method according to claim 7, wherein the base-substrate is prepared from glass, the conductive layer from chromium, and the conductive oxide layer from ITO.
Claim 10
Dependent Claim
27 words
The method according to claim 1, wherein the layer composed of the metal crystal particles having a larger diameter has a thickness of less than 2 μm.
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) | 1992-08-07 | 1993-02-06 | 1993-08-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-08-07 | 1997-02-06 | 1997-08-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-08-07 | 2001-02-06 | 2001-08-08 | $7700.00 | Window Closed / Lapsed |