US5643831A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for forming solder balls on a plate having apertures using solder paste and transferring the solder balls to semiconductor device
Assignee: Fujitsu Ltd
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Filing: 1995-10-24
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Granted: 1997-07-01
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Expires: 2015-10-24
Abstract
Abstract A method for fabricating a semiconductor device using a solder ball forming plate having cavities. The plate is made from a silicon plate having a flat surface in a <110> crystallographic plane, and an orientation flat in a <1-11> crystallographic plane. The cavities are formed on the flat surface of the plate by etching, using a mask having openings in the shape of rhombus arranged such that one side of the rhombus is generally parallel to the <1-11> crystallographic plane. As a result, the cavities having wedge-shaped bottom are formed. The cavities are then filled with a solder paste and are heated to form solder balls in the cavities while the plate in an inclined position. The solder balls are then transferred from the plate to a semiconductor chip.
Inventors
- 👤 Masayuki Ochiai
- 👤 Hidefumi Ueda
- 👤 Michio Sono
- 👤 Ichiro Yamaguchi
- 👤 Kazuhiko Mitobe
- 👤 Koki Otake
- 👤 Junichi Kasai
- 👤 Nobuo Kamehara
- 👤 Yasuo Yamagishi
- 👤 Masataka Mizukoshi
- 👤 Yutaka Yamada
- 👤 Susumu Abe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 11:28
CPC Classifications
H; H05; H05K; H05K3/00; H05K3/30; H05K3/32; H05K3/34; H05K3/3465; H05K3/3485; B; B23; B23K; B23K3/00; B23K3/06; B23K3/0607; B23K3/0623; H10; H10P; H10P72/00; H10P72/70; H10P72/74; H10W; H10W70/00; H10W70/099; H05K2201/00; H05K2201/10; H05K2201/10613; H05K2201/10954; H05K2201/10992; H05K2203/00; H05K2203/01; H05K2203/0104; H05K2203/0113; H05K2203/0147; H05K2203/016; H05K2203/03; H05K2203/0338; H05K2203/04; H05K2203/041; H05K2203/14; H05K2203/1476; H05K3/346; H05K3/3478; H05K3/3489; H10W72/00; H10W72/01; H10W72/012; H10W72/01204; H10W72/01221; H10W72/01225; H10W72/20; H10W72/251
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
116 words
A method for fabricating a semiconductor device, said method comprising the steps of: preparing a plate having a flat surface, a <110> crystallographic plane, and a <1-11> crystallographic plane, said flat surface being in the <110> crystallographic plane; forming a plurality of cavities on the flat surface of the plate by etching, using a mask having apertures in the shape of a parallelogram arranged such that one side of the parallelogram is generally parallel to the <1-11> crystallographic plane; filling the cavities with a solder paste; heating the plate to form solder balls in the cavities; and transferring the solder balls from the plate to a first member onto which solder bumps are to be formed.
Claim 2
Independent Claim
116 words
A method for fabricating a semiconductor device, said method comprising the steps of: preparing a plate having a flat surface, a <110> crystallographic plane, and a <1-11> crystallographic plane, said flat surface being in the <110> crystallographic plane; forming a plurality of cavities on the flat surface of the plate by etching, using a mask having apertures in the shape of a parallelogram arranged such that one side of the parallelogram is generally parallel to the <1-11> crystallographic plane; filling the cavities with a solder paste; heating the plate to form solder balls in the cavities; and transferring the solder balls from the plate to a first member onto which solder bumps are to be formed.
Claim 3
Dependent Claim
35 words
A method for fabricating a semiconductor device according to claim 1, wherein the first member comprises one of a semiconductor chip, an IC chip, a semiconductor package, a printed wiring board, and a TAB member.
Claim 4
Dependent Claim
22 words
A method for fabricating a semiconductor device according to claim 1, wherein the mask has apertures in the shape of a rhombus.
Claim 5
Dependent Claim
18 words
A method for fabricating a semiconductor device according to claim 1, wherein the plate comprises a silicon plate.
Claim 6
Dependent Claim
20 words
A method for fabricating a semiconductor device according to claim 1, wherein the plate is covered by a protective layer.
Claim 7
Dependent Claim
19 words
A method for fabricating a semiconductor device according to claim 5, wherein the protective layer comprises an oxide layer.
Claim 8
Dependent Claim
19 words
A method for fabricating a semiconductor device according to claim 5, wherein the protective layer comprises a nitride layer.
Claim 9
Dependent Claim
22 words
A method for fabricating a semiconductor device according to claim 1, wherein the step of etching is carried out by dry etching.
Claim 10
Dependent Claim
22 words
A method for fabricating a semiconductor device according to claim 1, wherein the step of etching is carried out by anisotropy etching.
Claim 11
Dependent Claim
32 words
A method for fabricating a semiconductor device according to claim 1, wherein the step of heating is carried out while the plate is arranged in an inclined position relative to a horizontal.
Claim 12
Dependent Claim
40 words
A method for fabricating a semiconductor device according to claim 1, wherein the step of filling the cavities is carried out after a nucleus material for forming a solder ball is provided at a position in each of the cavities.
Claim 13
Independent Claim
82 words
A method for fabricating a semiconductor device, said method comprising the steps of: preparing a plate having a flat surface; forming a plurality of cavities on the flat surface of the plate; filling the cavities with a solder paste; heating the plate to form solder balls in the cavities while the plate is arranged in an inclined position relative to a horizontal; and transferring the solder balls from the plate to a first member onto which solder bumps are to be formed.
Claim 14
Independent Claim
82 words
A method for fabricating a semiconductor device, said method comprising the steps of: preparing a plate having a flat surface; forming a plurality of cavities on the flat surface of the plate; filling the cavities with a solder paste; heating the plate to form solder balls in the cavities while the plate is arranged in an inclined position relative to a horizontal; and transferring the solder balls from the plate to a first member onto which solder bumps are to be formed.
Claim 15
Independent Claim
86 words
A method for fabricating a semiconductor device, said method comprising the steps of: preparing a plate having a flat surface; forming a plurality of cavities on the flat surface of the plate; providing a nucleus material for forming a solder ball at a position in each of the cavities; filling the cavities with a solder paste; heating the plate to form solder balls in the cavities; and transferring the solder balls from the plate to a first member onto which solder bumps are to be formed.
Claim 16
Independent Claim
86 words
A method for fabricating a semiconductor device, said method comprising the steps of: preparing a plate having a flat surface; forming a plurality of cavities on the flat surface of the plate; providing a nucleus material for forming a solder ball at a position in each of the cavities; filling the cavities with a solder paste; heating the plate to form solder balls in the cavities; and transferring the solder balls from the plate to a first member onto which solder bumps are to be formed.
References Cited (Backward Citations)
DE242908C
Cited
US3458925A
Cited
JPS533980A
Cited
JPS6225435A
Cited
JPS63289824A
Cited
US5136363A
Cited
JPH01308037A
Cited
US5208186A
Cited
US5135606A
Cited
US5145552A
Cited
JPH0414834A
Cited
JPH04263433A
Cited
JPH04263434A
Cited
JPH04264731A
Cited
JPH06124953A
Cited
US5381848A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2000-06-30 | 2000-12-30 | 2001-07-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-06-30 | 2004-12-30 | 2005-07-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-06-30 | 2008-12-30 | 2009-07-01 | $7700.00 | Window Closed / Lapsed |