US5542601A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rework process for semiconductor chips mounted in a flip chip configuration on an organic substrate
Assignee: International Business Machines Corp
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Filing: 1995-02-24
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Granted: 1996-08-06
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Expires: 2015-02-24
Abstract
Abstract A new rework process for semiconductor chips mounted in a flip chip configuration, via solder balls, on an organic substrate is disclosed.
Inventors
- 👤 Kenneth M. Fallon
- 👤 Miguel A. Jimarez
- 👤 Joseph E. Zdimal
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 21:05
CPC Classifications
H; H10; H10W; H10W70/00; H10W70/60; H10W70/67; H10W70/68; H10W72/00; H10W72/071; H10W72/0711; H10W72/07141; H10W72/07178; H10W72/072; H10W72/07231; H10W72/07236; H10W72/07251; H10W72/20
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
206 words
A rework process for a defective semiconductor chip attached via a plurality of solder regions to contact pads on an organic substrate, where each of said plurality includes a first solder region, having a first, relatively high melting temperature, in physical contact with a contact pad of said chip, and a second solder region, having a second, relatively low melting temperature, in physical contact with a contact pad of said organic substrate, comprising the steps of: heating each of said plurality of solder regions to at least said second melting temperature; removing said defective chip, including at least the first solder region of each of said plurality of solder regions, from said organic substrate; removing substantially all of said plurality of solder regions remaining on said contact pads of said organic substrate; applying a preselected amount of solder, having said second melting temperature, to each of said contact pads of said organic substrate; bringing a plurality of solder regions, attached to contact pads of a functional semiconductor chip and having said first melting temperature, into contact with the solder applied to said contact pads of said organic substrate; and heating said solder applied to said contact pads of said organic substrate to said second melting temperature.
Claim 2
Dependent Claim
206 words
A rework process for a defective semiconductor chip attached via a plurality of solder regions to contact pads on an organic substrate, where each of said plurality includes a first solder region, having a first, relatively high melting temperature, in physical contact with a contact pad of said chip, and a second solder region, having a second, relatively low melting temperature, in physical contact with a contact pad of said organic substrate, comprising the steps of: heating each of said plurality of solder regions to at least said second melting temperature; removing said defective chip, including at least the first solder region of each of said plurality of solder regions, from said organic substrate; removing substantially all of said plurality of solder regions remaining on said contact pads of said organic substrate; applying a preselected amount of solder, having said second melting temperature, to each of said contact pads of said organic substrate; bringing a plurality of solder regions, attached to contact pads of a functional semiconductor chip and having said first melting temperature, into contact with the solder applied to said contact pads of said organic substrate; and heating said solder applied to said contact pads of said organic substrate to said second melting temperature.
Claim 3
Dependent Claim
78 words
The rework process of claim 1, wherein said step of removing substantially all of said plurality of solder regions remaining on said contact pads of said organic substrate includes the step of placing a metallic block in contact with said plurality of solder regions remaining on said contact pads of said organic substrate, said metallic block having a surface adapted to be wetted by said plurality of solder regions remaining on said contact pads of said organic substrate.
Claim 4
Dependent Claim
59 words
The rework process of claim 1, wherein said applying step includes the step of bringing a metallic layer, bearing a plurality of preselected amounts of solder in a pattern corresponding to that of the contact pads of said organic substrate, into proximity with said contact pads of said organic substrate and heating said plurality of preselected amounts of solder.
Claim 5
Dependent Claim
15 words
The rework process of claim 1, wherein said organic substrate is a printed circuit board.
Claim 6
Dependent Claim
15 words
The rework process of claim 1, wherein said organic substrate is a printed circuit card.
Claim 7
Dependent Claim
228 words
A rework process for a defective semiconductor chip attached via a first plurality of solder regions to contact pads on an organic substrate, where each of said first plurality includes a first solder region, having a first, relatively high melting temperature, in physical contact with a contact pad of said chip, and a second solder region, having a second, relatively low melting temperature, in physical contact with a contact pad of said organic substrate, comprising the steps of: heating each of said first plurality of solder regions to at least said second melting temperature; removing said defective chip, including at least the first solder region of each of said first plurality of solder regions, from said organic substrate; removing substantially all of said first plurality of solder regions remaining on said contact pads of said organic substrate; bringing a second plurality of solder regions, attached to contact pads of a functional semiconductor chip, into proximity with said contact pads of said organic substrate, each of said second plurality including third and fourth solder regions, each of said third solder regions exhibiting said first melting temperature and each of said fourth solder regions exhibiting a melting temperature different from either said first melting temperature or said second melting temperature; and modifying each of said fourth solder regions to exhibit a melting temperature substantially equal to said second melting temperature.
Claim 8
Dependent Claim
228 words
A rework process for a defective semiconductor chip attached via a first plurality of solder regions to contact pads on an organic substrate, where each of said first plurality includes a first solder region, having a first, relatively high melting temperature, in physical contact with a contact pad of said chip, and a second solder region, having a second, relatively low melting temperature, in physical contact with a contact pad of said organic substrate, comprising the steps of: heating each of said first plurality of solder regions to at least said second melting temperature; removing said defective chip, including at least the first solder region of each of said first plurality of solder regions, from said organic substrate; removing substantially all of said first plurality of solder regions remaining on said contact pads of said organic substrate; bringing a second plurality of solder regions, attached to contact pads of a functional semiconductor chip, into proximity with said contact pads of said organic substrate, each of said second plurality including third and fourth solder regions, each of said third solder regions exhibiting said first melting temperature and each of said fourth solder regions exhibiting a melting temperature different from either said first melting temperature or said second melting temperature; and modifying each of said fourth solder regions to exhibit a melting temperature substantially equal to said second melting temperature.
Claim 9
Dependent Claim
26 words
The rework process of claim 6, wherein said modifying step includes the step of heating said second plurality of solder regions to said second melting temperature.
Claim 10
Dependent Claim
81 words
The rework process of claim 6, wherein said step of removing substantially all of said first plurality of solder regions remaining on said contact pads of said organic substrate includes the step of placing a metallic block in contact with said first plurality of solder regions remaining on said contact pads of said organic substrate, said metallic block having a surface adapted to be wetted by said first plurality of solder regions remaining on said contact pads of said organic substrate.
Claim 11
Dependent Claim
15 words
The rework process of claim 6, wherein said organic substrate is a printed circuit board.
Claim 12
Dependent Claim
15 words
The rework process of claim 6, wherein said organic substrate is a printed circuit card.
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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) | 1999-08-06 | 2000-02-05 | 2000-08-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-08-06 | 2004-02-05 | 2004-08-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-08-06 | 2008-02-05 | 2008-08-06 | $7700.00 | Window Closed / Lapsed |