US5697148A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Flip underfill injection technique
Assignee: Motorola Solutions Inc
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Filing: 1995-08-22
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Granted: 1997-12-16
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Expires: 2015-08-22
Abstract
Abstract A method for dispensing underfill material between a flip chip bonded to substrate. The method requires an underfill injection port to be drilled through the substrate prior to reflow such that underfill material can be dispensed between the flip chip and substrate through the port. After reflow is completed, a pressurized pump delivers a predetermined amount of underfill under hydraulic pressure through the underfill injection port between the flip chip and substrate. Once injected, the underfill migrates between the flip chip and substrate via capillary action pushing out any air around the joints.
Inventors
- 👤 James George Lance, Jr.
- 👤 Robert Kenneth Doot
- 👤 Karl Marcus Wahlfrid
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 20:33
CPC Classifications
H; H10; H10W; H10W74/00; H10W74/01; H10W74/012; H10W72/00; H10W72/30; H10W74/10; H10W74/15; H10W70/00; H10W70/60; H10W70/67; H10W70/68; H10W70/681; H10W72/071; H10W72/072; H10W72/073; H10W72/851; H10W72/853; H10W72/856; H10W90/00; H10W90/701; H10W90/721; H10W90/724; Y; Y10; Y10S; Y10S428/00; Y10S428/901; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49117; Y10T29/49124; Y10T29/4913; Y10T29/49144
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
102 words
A method for underfilling a flip chip attached to a substrate, said substrate having a footprint where said flip chip is attached to the substrate utilizing solder joints, said method comprising the steps of: providing a hole through the substrate under said footprint prior to attaching said flip chip to said substrate; aligning a means for dispensing an underfill material with said hole after said flip chip is attached to said substrate; and dispensing, under hydraulic pressure, a predetermined amount of underfill material through said hole to substantially eliminate air between said flip chip and said substrate and about the solder joints.
Claim 2
Independent Claim
102 words
A method for underfilling a flip chip attached to a substrate, said substrate having a footprint where said flip chip is attached to the substrate utilizing solder joints, said method comprising the steps of: providing a hole through the substrate under said footprint prior to attaching said flip chip to said substrate; aligning a means for dispensing an underfill material with said hole after said flip chip is attached to said substrate; and dispensing, under hydraulic pressure, a predetermined amount of underfill material through said hole to substantially eliminate air between said flip chip and said substrate and about the solder joints.
Claim 3
Dependent Claim
19 words
The method of underfilling as set forth in claim 1 wherein said hole is centrally located in said footprint.
Claim 4
Dependent Claim
20 words
The method of underfilling as set forth in claim 1 wherein said means for dispensing is a needle and pump.
Claim 5
Dependent Claim
22 words
The method of underfilling as set forth in claim 1 wherein said means for dispensing is an elastomeric dispensing tip and pump.
Claim 6
Dependent Claim
38 words
A method for underfilling as set forth in claim 1 further comprising the step of: allowing the underfill material to migrate between said flip chip and said substrate utilizing capillary action to reduce voids about the solder joints.
Claim 7
Independent Claim
137 words
A method for attaching a flip chip having a plurality of solder balls to a substrate having a footprint comprising a plurality of corresponding solder balls, said method comprising: providing a hole in said substrate beneath said plurality of corresponding solder balls on said substrate; fluxing a predetermined area on said substrate; aligning said plurality of solder balls proximal to said plurality of corresponding solder balls; heating said flip chip and said substrate such that said plurality of solder balls and said plurality of corresponding solder balls coalesce into a plurality of solder joints; aligning a means for dispensing an underfill material with said hole; and dispensing, under hydraulic pressure, a predetermined amount of underfill material through said hole to substantially eliminate air between said flip chip and said substrate and about said plurality of solder joints.
Claim 8
Independent Claim
137 words
A method for attaching a flip chip having a plurality of solder balls to a substrate having a footprint comprising a plurality of corresponding solder balls, said method comprising: providing a hole in said substrate beneath said plurality of corresponding solder balls on said substrate; fluxing a predetermined area on said substrate; aligning said plurality of solder balls proximal to said plurality of corresponding solder balls; heating said flip chip and said substrate such that said plurality of solder balls and said plurality of corresponding solder balls coalesce into a plurality of solder joints; aligning a means for dispensing an underfill material with said hole; and dispensing, under hydraulic pressure, a predetermined amount of underfill material through said hole to substantially eliminate air between said flip chip and said substrate and about said plurality of solder joints.
Claim 9
Dependent Claim
23 words
The method of for attaching a flip chip as set forth in claim 6 wherein said hole is centrally located in said footprint.
Claim 10
Dependent Claim
26 words
The method for attaching a flip chip as set forth in claim 6 wherein said means for dispensing an underfill material is a needle and pump.
Claim 11
Dependent Claim
25 words
The method for attaching a flip chip as set forth in claim 6 wherein said means for dispensing is an elastomeric dispensing tip and pump.
Claim 12
Dependent Claim
42 words
A method for attaching a flip chip as set forth in claim 6 further comprising the step of: allowing the underfill material to migrate between said flip chip and said substrate utilizing capillary action to reduce voids about the plurality of joints.
Claim 13
Independent Claim
131 words
A method for attaching a flip chip having a plurality of connecting pads to a substrate having a footprint comprising a corresponding plurality of connecting pads, said method comprising: providing a connection media between said plurality of connecting pads and said corresponding plurality of connecting pads; providing a hole in said substrate beneath said plurality of corresponding connecting pads; aligning said plurality of connecting pads proximal to said plurality of corresponding connecting pads; connecting said plurality of connecting pads with said plurality of corresponding connecting pads; aligning a means for dispensing an underfill material with said hole; and dispensing, under hydraulic pressure, a predetermined amount of underfill material through said hole to substantially eliminate voids in the underfill material between said flip chip and said substrate and about the connection media.
Claim 14
Independent Claim
131 words
A method for attaching a flip chip having a plurality of connecting pads to a substrate having a footprint comprising a corresponding plurality of connecting pads, said method comprising: providing a connection media between said plurality of connecting pads and said corresponding plurality of connecting pads; providing a hole in said substrate beneath said plurality of corresponding connecting pads; aligning said plurality of connecting pads proximal to said plurality of corresponding connecting pads; connecting said plurality of connecting pads with said plurality of corresponding connecting pads; aligning a means for dispensing an underfill material with said hole; and dispensing, under hydraulic pressure, a predetermined amount of underfill material through said hole to substantially eliminate voids in the underfill material between said flip chip and said substrate and about the connection media.
Claim 15
Dependent Claim
22 words
The method for attaching a flip chip as set forth in claim 11 wherein said hole is centrally located in said footprint.
Claim 16
Dependent Claim
26 words
The method for attaching a flip chip as set forth in claim 11 wherein said means for dispensing an underfill material is a needle and pump.
Claim 17
Dependent Claim
25 words
The method for attaching a flip chip as set forth in claim 11 wherein said means for dispensing is an elastomeric dispensing tip and pump.
Claim 18
Dependent Claim
30 words
The method for attaching a flip chip as set forth in claim 11 wherein said connection media is a plurality of solder balls on said flip chip and said substrate.
Claim 19
Dependent Claim
27 words
The method for attaching a flip chip as set forth in claim 11 wherein said connection media is a plurality of eutectic bumps on said flip chip.
Claim 20
Dependent Claim
30 words
The method for attaching a flip chip as set forth in claim 11 wherein said connection media is a plurality of conductive adhesive columns on said flip chip or substrate.
Claim 21
Dependent Claim
41 words
The method for attaching a flip chip as set forth in claim 11 further comprising the step of: allowing the underfill material to migrate between said flip chip and said substrate utilizing capillary action to eliminate air about the connection media.
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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) | 2000-12-15 | 2001-06-16 | 2001-12-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-12-15 | 2005-06-16 | 2005-12-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-12-15 | 2009-06-16 | 2009-12-16 | $7700.00 | Window Closed / Lapsed |