Patent US4427992A successfully refreshed from Google Patents.
US4427992A
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Method for incorporating a desiccant in a semiconductor package
Assignee: Motorola Solutions Inc
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Filing: 1977-11-14
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Granted: 1984-01-24
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Expires: 1997-11-14
Abstract
Abstract A desiccant for semiconductor packaging which may be applied in liquid form consists essentially of approximately 60% by weight absolute ethyl alcohol, 25% by weight ethyl acetate, 5% by weight water, 5% by weight a source of boron, aluminum or phosphorus and 5% by weight of an organic silane having the structural formula: ##STR1## where R 1 is a radical selected from the group consisting of H - , CH 2 ═CH - , CH 3 O - , C 2 H 5 O - , CH 3 CO 2 - , C 2 H 5 CO - , and C 3 H 7 O - , and R is a radical selected from the group consisting of CH 3 O - , C 2 H 5 O - , C 3 H 7 O - , CH 3 CO 2 - , C 2 H 5 CO 2 - , Si + , OH - , and O - . The sources of boron, aluminum, and phosphorus may be halides, oxides or nitrates. Also a process for incorporating the foregoing into semiconductor package and process for formulating the above solution.
Inventors
- 👤 Kim Ritchie
- 👤 James N. Smith
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 05:04
CPC Classifications
H; H10; H10W; H10W76/00; H10W76/40; H10W76/42; H10W76/48; H10W72/00; H10W72/50; H10W72/551; H10W72/552; H10W72/5524; H10W90/00; H10W90/701; H10W90/751; H10W90/756; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49117
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
102 words
A method of packaging a semiconductor chip in a hermetic enclosure formed by assembly of a first enclosure portion bearing said semiconductor chip to a second enclosure portion, said enclosure including a desiccant, the improvement comprising placing a coating of a liquid material consisting essentially of ethyl alcohol, water, ethyl acetate, tetraethylorthosilicate, and 0.1% to 10% by weight of a metallic ion selected from the group consisting of boron, aluminum, and phosphorus, on part of said second enclosure portion prior to said assembly, and drying said coating in the range 80°-500° C. to provide a desiccant adherent to said second enclosure portion.
Claim 2
Independent Claim
102 words
A method of packaging a semiconductor chip in a hermetic enclosure formed by assembly of a first enclosure portion bearing said semiconductor chip to a second enclosure portion, said enclosure including a desiccant, the improvement comprising placing a coating of a liquid material consisting essentially of ethyl alcohol, water, ethyl acetate, tetraethylorthosilicate, and 0.1% to 10% by weight of a metallic ion selected from the group consisting of boron, aluminum, and phosphorus, on part of said second enclosure portion prior to said assembly, and drying said coating in the range 80°-500° C. to provide a desiccant adherent to said second enclosure portion.
Claim 3
Dependent Claim
11 words
The method of claim 1 where said metallic ion is aluminum.
Claim 4
Dependent Claim
21 words
The method of claim 1, where the source of said metallic ion comprises the halides, oxides, and nitrates of said group.
Claim 5
Dependent Claim
37 words
The method of claim 1, where the weight percentage of tetraethylorthosilicate in said liquid material is greater than the percentage of said metallic ion and less the percentage of ethyl alcohol and the percentage of ethyl acetate.
Claim 6
Dependent Claim
36 words
A method of packaging a semiconductor device as recited in claim 1 and further including the steps of drying said coating at 80°-200° C. to form a porous complex silicate adhering to said second enclosure portion.
Claim 7
Dependent Claim
13 words
The method of claim 5, where said silicate has a density of 1.4-1.8.
Claim 8
Dependent Claim
40 words
A method of packaging a semiconductor device as recited in claim 1, 5 or 6 and further including the step of exposing said coating to a temperature of 200°-500° C. for 10-30 minutes during the assembly of said enclosure portions.
Claim 9
Independent Claim
196 words
A method of packaging a semiconductor chip in a hermetic enclosure formed by assembly of a first enclosure portion bearing said semiconductor chip to a second enclosure portion, said enclosure including a desiccant, the improvement comprising placing a coating of a liquid material consisting essentially of ethyl alcohol, water, ethyl acetate, 0.1% to 10% by weight of a metallic ion selected from the group consisting of boron, aluminum, and phosphorus, and an organic silane having the structural formula ##STR6## where R 1 is a radical selected from the group consisting of H - , CH 2 ═CH - , CH 3 0 - , C 2 H 5 O - , CH 3 CO 2 - , C 3 H 7 O - , and R is selected from the group consisting of CH 3 O - , C 2 H 5 O - , C 3 H 7 O - , CH 3 CO 2 - , and C 2 H 5 CO 2 - on part of said second enclosure portion prior to said assembly, and drying said coating in the range 80°-500° C. to provide a desiccant adherent to said second enclosure portion.
Claim 10
Independent Claim
196 words
A method of packaging a semiconductor chip in a hermetic enclosure formed by assembly of a first enclosure portion bearing said semiconductor chip to a second enclosure portion, said enclosure including a desiccant, the improvement comprising placing a coating of a liquid material consisting essentially of ethyl alcohol, water, ethyl acetate, 0.1% to 10% by weight of a metallic ion selected from the group consisting of boron, aluminum, and phosphorus, and an organic silane having the structural formula ##STR6## where R 1 is a radical selected from the group consisting of H - , CH 2 ═CH - , CH 3 0 - , C 2 H 5 O - , CH 3 CO 2 - , C 3 H 7 O - , and R is selected from the group consisting of CH 3 O - , C 2 H 5 O - , C 3 H 7 O - , CH 3 CO 2 - , and C 2 H 5 CO 2 - on part of said second enclosure portion prior to said assembly, and drying said coating in the range 80°-500° C. to provide a desiccant adherent to said second enclosure portion.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-01-23 | 1987-07-25 | 1988-01-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-01-23 | 1991-07-25 | 1992-01-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-01-23 | 1995-07-25 | 1996-01-24 | $7700.00 | Window Closed / Lapsed |