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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
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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 12:30
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.

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

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