US5176771A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Multilayer ceramic tape substrate having cavities formed in the upper layer thereof and method of fabricating the same by printing and delamination
Assignee: Raytheon Co
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Filing: 1991-12-23
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Granted: 1993-01-05
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Expires: 2011-12-23
Abstract
Abstract A plurality of sheets (12,16,18) of Low-Temperature-Cofired-Ceramic (LTCC) tape or other fusible ceramic tape are laminated together. A pattern (10) is printed on an external surface (12a) of the laminated structure (20) of a material having a thermal shrinkage rate which is different from that of the tape. The pattern (10) may be printed before or after lamination. The structure (20) is then baked to burn organic materials out of the tape. During this step, the pattern (10) and underlying portions (12b,12c) of the upper tape sheet (12) shrink to a different extent than the bulk of the structure (20), and delaminate therefrom to form cavities (26,28) having the same shape as the pattern (10). The structure (20) is then fired to sinter the tape and form a fused multilayer substrate (32). The cavities (26,28) may be filled with an electrically conductive or resistive material (36,38). Conductor traces (76,82;78,84) which are considerably thickner than can be fabricated using conventional thick film technology may be formed by filling cavities (72,74) with conductive material (76,78), and printing more conductive material (82,84) over the material (76,78) in the cavitities (72,74). Alternatively, cavities (94,96) may be filled with an adhesive (98,100) for bonding a component such as a cover lid (104) to a multilayer substrate (92).
Inventors
- 👤 Pedro L. Bravo
- 👤 Roman Klyachman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 17:05
CPC Classifications
H; H10; H10W; H10W70/00; H10W70/01; H10W70/05; H10W70/098; Y; Y10; Y10T; Y10T156/00; Y10T156/11; Y10T156/1142
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
126 words
A method of fabricating a multilayer microelectronic substrate, comprising the steps of: (a) providing a plurality of thermally fusible sheets having a first thermal shrinkage rate; (b) adhering a material pattern having a predetermined shape and a second thermal shrinkage rate which is different from said first rate on a surface of one of said sheets; (c) laminating said sheets together such that said surface faces externally; and (d) heating said laminated sheets at a predetermined temperature at which said pattern and the portion of the sheet to which said pattern is adhered shrink to a different extent than the bulk of said laminated sheets and delaminate therefrom to form a cavity having said shape in said surface, and said bulk fuses to form said substrate.
Claim 2
Independent Claim
126 words
A method of fabricating a multilayer microelectronic substrate, comprising the steps of: (a) providing a plurality of thermally fusible sheets having a first thermal shrinkage rate; (b) adhering a material pattern having a predetermined shape and a second thermal shrinkage rate which is different from said first rate on a surface of one of said sheets; (c) laminating said sheets together such that said surface faces externally; and (d) heating said laminated sheets at a predetermined temperature at which said pattern and the portion of the sheet to which said pattern is adhered shrink to a different extent than the bulk of said laminated sheets and delaminate therefrom to form a cavity having said shape in said surface, and said bulk fuses to form said substrate.
Claim 3
Independent Claim
20 words
A method as in claim in which step (a) comprises providing said sheets in the form of ceramic tape sheets.
Claim 4
Dependent Claim
21 words
A method as in claim 1, in which step (a) comprises providing said sheets in the form of glass-ceramic tape sheets.
Claim 5
Dependent Claim
15 words
A method as in claim 1, in which step (b) is performed before step (c).
Claim 6
Dependent Claim
15 words
A method as in claim 1, in which step (b) is performed after step (c).
Claim 7
Dependent Claim
14 words
A method as in claim 1, in which step (b) comprises thick film printing.
Claim 8
Dependent Claim
18 words
A method as in claim 6, in which step (b) comprises forming said pattern of electrically conductive ink.
Claim 9
Dependent Claim
28 words
A method as in claim 7, in which step (b) comprises providing said ink as including a material selected from the group consisting of silver, platinum and palladium.
Claim 10
Dependent Claim
25 words
A method as in claim 1, further comprising the step, performed after step (d), of: (e) adhering a solid, electrically conductive material inside said cavity.
Claim 11
Dependent Claim
35 words
A method as in claim 9, in which step (e) comprises the substeps of: (f) depositing said conductive material inside said cavity in fluid form; and (g) heating said substrate to solidify said conductive material.
Claim 12
Dependent Claim
14 words
A method as in claim 10, in which step (f) comprises thick film printing.
Claim 13
Dependent Claim
22 words
A method as in claim 11, in which step (f) comprises providing said conductive material in the form of electrically conductive paste.
Claim 14
Dependent Claim
25 words
A method as in claim 1, further comprising the step, performed after step (d), of: (e) adhering a solid, electrically resistive material inside said cavity.
Claim 15
Dependent Claim
35 words
A method as in claim 13, in which step (e) comprises the substeps of: (f) depositing said resistive material inside said cavity in fluid form; and (g) heating said substrate to solidify said resistive material.
Claim 16
Dependent Claim
14 words
A method as in claim 14, in which step (f) comprises thick film printing.
Claim 17
Dependent Claim
22 words
A method as in claim 15, in which step (f) comprises providing said resistive material in the form of electrically resistive paste.
Claim 18
Dependent Claim
49 words
A method as in claim 1, further comprising the steps, performed after step (d), of: (e) depositing an adhesive material inside said cavity in fluid form; (f) holding a component in contact with said adhesive material; and (g) curing said adhesive material to bond the component to said substrate.
Claim 19
Dependent Claim
23 words
A method as in claim 1, further comprising the step, performed after step (d), of: (e) adhering an electrical component inside said cavity.
Claim 20
Dependent Claim
33 words
A method as in claim 18, further comprising the steps of: (f) adhering an electrically conductive contact to said surface; and (g) after performing step (e), electrically interconnecting said component and said contact.
Claim 21
Dependent Claim
13 words
A method as in claim 19, in which step (g) comprises wire bonding.
Claim 22
Dependent Claim
55 words
A method as in claim 1, further comprising the steps, performed after step (d), of: (e) adhering a solid, electrically conductive material inside said cavity; and (f) adhering an electrically conductive contact to said surface, at least a portion of said contact overlying at least a portion of said conductive material in electrical connection therewith.
Claim 23
Independent Claim
71 words
A method of forming a cavity in a surface of a laminated ceramic tape substrate, comprising the steps of: (a) adhering a material pattern to said surface, said material having a thermal shrinkage rate which is different from the thermal shrinkage rate of said ceramic tape; and (b) heating said substrate such that said pattern and an underlying portion of said ceramic tape delaminates from said substrate to form said cavity.
Claim 24
Independent Claim
71 words
A method of forming a cavity in a surface of a laminated ceramic tape substrate, comprising the steps of: (a) adhering a material pattern to said surface, said material having a thermal shrinkage rate which is different from the thermal shrinkage rate of said ceramic tape; and (b) heating said substrate such that said pattern and an underlying portion of said ceramic tape delaminates from said substrate to form said cavity.
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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) | 1996-01-05 | 1996-07-06 | 1997-01-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-01-05 | 2000-07-06 | 2001-01-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-01-05 | 2004-07-06 | 2005-01-05 | $7700.00 | Window Closed / Lapsed |