US3793064A
Expired / Lapsed
US
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Product and process for cavity metallization of semiconductor packages
Assignee: EIDP Inc
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Filing: 1971-11-15
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Granted: 1974-02-19
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Expires: 1991-11-15
Abstract
Abstract A process and composition are provided for the gold metallization of the bottoms of cavities in semiconductor packages wherein the walls of such cavities are left free from gold which might otherwise create short circuits between the face of the package and the bottom of the cavity. Semiconductor packages provided by the use of this process are different from and preferred over packages produced by their prior methods.
Inventors
- 👤 J Budd
- 👤 W Robson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 06:43
CPC Classifications
H; H10; H10W; H10W76/00; H10W76/10; H10W76/12; H10W76/15; H10W76/157; H10W70/00; H10W70/60; H10W70/62; H10W70/65; H10W70/654; H10W70/655; H10W70/67; H10W70/68; H10W70/682; H10W72/00; H10W72/01; H10W72/019; H10W72/01961; H10W72/071; H10W72/073; H10W72/075; H10W72/07531; H10W72/07532; H10W72/07533; H10W72/30; H10W72/50; H10W72/59; H10W72/851; H10W72/874; H10W72/884; H10W90/00; H10W90/701; H10W90/751; H10W90/754; H10W99/00; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49117; Y10T29/49124; Y10T29/4913
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
104 words
In a semiconductor package comprising a substrate having a plurality of metallized conductors thereon and a cavity recessed therein, and a mounting pad disposed on the bottom of said cavity for mounting a semiconductor chip, said pad comprising fired layers of a first composition consisting essentially of a glass frit in a vehicle, and a second gold metallization composition consisting essentially of at least 50 percent, by weight, gold powder dispersed in an inert vehicle, essentially all of said powder having an equivalent spherical diameter of at least about 2 microns, wherein the walls of said cavity are substantially free of said fired layers.
Claim 2
Dependent Claim
123 words
In a semiconductor packaGe comprising a substrate having a plurality of metallized conductors thereon and a cavity recessed therein, and a mounting pad disposed on the bottom of said cavity for mounting a semiconductor chip, said pad comprising fired layers of a first gold metallization consisting essentially of at least 0.1 percent, by weight, glass frit and at least 40 percent, by weight, gold powder dispersed in an inert vehicle, and a second gold metallization composition consisting essentially of at least about 50 percent gold powder, by weight, dispersed in an inert vehicle, essentially all of said gold powder having an equivalent spherical diameter of at least about 2 microns, wherein the walls of said cavity are substantially free of said fired layers.
Claim 3
Dependent Claim
169 words
In a process for producing a mounting pad in a semiconductor chip package, said package comprising a substrate having a plurality of metallized conductors thereon and having a cavity recessed therein for receiving a semiconductor chip, the improvement comprising the steps of: a. placing a quantity of a metallizing composition in said cavity, said metallizing composition consisting essentially of at least 0.1 percent, by weight, glass frit and at least 40 percent, by weight, gold powder dispersed in an inert vehicle, essentially all of said gold powder having an equivalent spherical diameter of at least about 2 microns, b. permitting said metallizing composition to spread over the bottom of said cavity and said gold powder to settle thereon, c. evaporating enough of said inert vehicle so that blister formation upon subsequent heating is minimized, and d. heating said cavity to sinter said metallizing composition in the bottom of said cavity to form said mounting pad, and leaving the walls of said cavity substantially free of said sintered metallizing composition.
Claim 4
Dependent Claim
28 words
A process according to claim 4 in which said metallizing composition contains, by weight, about 0.8 to 6 percent glass frit and 40 to 88 percent gold powder.
Claim 5
Dependent Claim
20 words
A process according to claim 4 in which said metallizing composition has a viscosity of less than about 10,000 centipoises.
Claim 6
Dependent Claim
25 words
A process according to claim 4 in which said glass frit crystallizes or has a softening point in the temperature range of 400* to 1,000*C.
Claim 7
Dependent Claim
19 words
A process according to claim 4 in which said inert vehicle comprises substituted cellulose dissolved in an organic solvent.
Claim 8
Dependent Claim
31 words
A process according to claim 4 in which the evaporating of step (c) is performed at 100* to 150*C. and the heating of step (d) is performed at 700 to 1,000*C.
Claim 9
Dependent Claim
174 words
In a process for producing a mounting pad in a semiconductor chip package, said package comprising a substrate having a plurality of metallized conductors thereon, and having a cavity recessed therein for receiving a semiconductor chip, and said cavity having a first layer of glass frit on a bottom surface, the improvement comprising the steps of: a. placing a quantity of a metallizing composition in said cavity, said metallizing composition consisting essentially of at least 50 percent, by weight, gold powder dispersed in an inert vehicle, essentially all of said gold powder having an equivalent spherical diameter of at least about 2 microns, b. permitting said metallizing composition to spread over the bottom of said cavity and said gold powder to settle thereon, c. evaporating enough of said inert vehicle so that blister formation upon subsequent heating is minimized, and d. heating said cavity to sinter said metallizing composition in the bottom of said cavity to form said mounting pad, and leaving the walls of said cavity substantially free of said sintered metallizing composition.
Claim 10
Dependent Claim
20 words
A process according to claim 10 in which said metallizing composition contains, by weight, 50 to 90 percent gold powder.
Claim 11
Dependent Claim
20 words
A process according to claim 10 in wHich said metallizing composition has a viscosity of less than about 10,000 centipoises.
Claim 12
Dependent Claim
25 words
A process according to claim 10 in which said glass frit crystallizes or has a softening point in the temperature range of 400* to 1,000*C.
Claim 13
Dependent Claim
19 words
A process according to claim 10 in which said inert vehicle comprises substituted cellulose dissolved in an organic solvent.
Claim 14
Dependent Claim
31 words
A process according to claim 10 in which the evaporating of step (c) is performed at 100* to 150*C. and the heating of step (d) is performed at 700* to 1,000*C.
Claim 15
Dependent Claim
264 words
In a process for producing a mounting pad in a semiconductor chip package, said package comprising a substrate having a plurality of metallized conductors thereon and having a cavity recessed therein for receiving a semiconductor chip, the improvement comprising the steps of: a. placing a quantity of a metallizing composition in said cavity, said metallizing composition consisting essentially of at least 0.1 percent, by weight, glass frit and at least 40 percent, by weight, gold powder dispersed in an inert vehicle, essentially all of said gold powder having an equivalent spherical diameter of at least about 2 microns, b. permitting said metallizing composition to spread over the bottom of said cavity and said gold powder to settle thereon, c. evaporating enough of said inert vehicle so that blister formation upon subsequent heating is minimized, d. placing a quantity of a second metallizing composition in said cavity on top of said first metallizing composition, said second metallizing composition consisting essentially of at least about 50 percent, by weight, gold powder dispersed in an inert vehicle, essentially all of said gold powder having an equivalent spherical diameter of at least about 2 microns, e. permitting said second metallizing composition to spread over said first metallizing composition and said gold powder to settle thereon, f. evaporating enough of said inert vehicle so that blister formation upon subsequent heating is minimized, and g. heating said cavity to sinter said first and second metallizing composition in the bottom of said cavity to form said mounting pad, leaving the walls of said cavity substantially free of said sintered metallizing composition.
Claim 16
Dependent Claim
23 words
A process according to claim 16 in which said cavity is heated to sinter said first metallizing composition between steps (c) and (d).
Claim 17
Dependent Claim
42 words
A process according to claim 16 in which said first metallizing composition contains, by weight, about 0.8 to 6 percent glass frit and 40 to 88 percent gold powder and said second metallizing composition contains about 50 to 90 percent gold powder.
Claim 18
Dependent Claim
20 words
A process according to claim 16 in which said metallizing composition has a viscosity of less than about 10,000 centipoises.
Claim 19
Dependent Claim
26 words
A process according to claim 16 in which said glass frit crystallizes or has a softening point in the temperature range of 400 to 1,000 C.
Claim 20
Dependent Claim
19 words
A process according to claim 16 in which said inert vehicle comprises substituted cellulose dissolved in an organic solvent.
Claim 21
Dependent Claim
33 words
A process according to claim 16 in which the evaporating of steps (c) and (f) is performed at 100* to 150*C. and the heating of step (g) is performed at 700* to 1000*C.
References Cited (Backward Citations)
US3347799A
Cited
US3407081A
Cited
US3385799A
Cited
US3520054A
Cited
US3458930A
Cited
US3609105A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-02-18 | 1977-08-20 | 1978-02-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-18 | 1981-08-20 | 1982-02-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-18 | 1985-08-20 | 1986-02-19 | $7700.00 | Window Closed / Lapsed |