US5058799A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Metallized ceramic substrate and method therefor
Assignee: Laserage Technology Corp
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Filing: 1990-04-23
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Granted: 1991-10-22
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Expires: 2010-04-23
Abstract
Abstract A metallized ceramic substrate having an enhanced bond strength between the ceramic substrate and a conductive metal layer bonded thereto is disclosed. The metallized ceramic substrate includes a heterogeneous juncture band between a ceramic workpiece and a layer of electrically conductive material. The metallized ceramic substrate is made by a process which includes an acid etchant step that increases the actual surface area of the treated surface of the ceramic workpiece without undermining the integrity of the ceramic surface while at the same time selectively attacking vitreous binder phase present between substrate grains and creating even deeper penetration at the relatively higher energy triple joint junctures. In this manner, metal anchor sites that enhance adhesion are provided. During subsequent high temperature firing these anchors hold the resulting composite together as a chemical bond is formed in addition to a mechanical bond or interlock.
Inventors
- 👤 Kalman F. Zsamboky
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 03:34
CPC Classifications
C; C04; C04B; C04B41/00; C04B41/45; C04B41/52; C04B41/80; C04B41/81; C04B41/89; C23; C23C; C23C18/00; C23C18/16; C23C18/1601; C23C18/1633; C23C18/1646; C23C18/165; C23C18/1653; C23C18/18; C23C18/1851; C23C18/1855; C23C18/1862; C23C18/1865; C23C18/1872; C23C18/1886; C23C18/1893; H; H05; H05K; H05K3/00; H05K3/10; H05K3/18; H05K3/181; Y; Y10; Y10S; Y10S228/00; Y10S228/903
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
76 words
In a method for the manufacture of a metal-ceramic composite by electroless deposition of a conductive metal layer onto a ceramic substrate, the improvement which comprises the step of acid etching grain boundaries of the working surface of the substrate, prior to electroless deposition of the conductive metal thereon, to a depth equal to at least about the diameter of an average grain at the working surface while maintaining a monolithic working surface of the substrate.
Claim 2
Dependent Claim
76 words
In a method for the manufacture of a metal-ceramic composite by electroless deposition of a conductive metal layer onto a ceramic substrate, the improvement which comprises the step of acid etching grain boundaries of the working surface of the substrate, prior to electroless deposition of the conductive metal thereon, to a depth equal to at least about the diameter of an average grain at the working surface while maintaining a monolithic working surface of the substrate.
Claim 3
Dependent Claim
29 words
The improvement in accordance with claim 1 wherein said ceramic is alumina and said acid etching is carried out with an aqueous phosphoric acid solution at an elevated temperature.
Claim 4
Dependent Claim
23 words
The improvement in accordance with claim 2 wherein the elevated temperature is at about the boiling temperature of the aqueous phosphoric acid solution.
Claim 5
Dependent Claim
36 words
The improvement in accordance with claim 1 wherein said acid etching is carried out to a depth greater than the diameter of an average grain at the working surface and without undermining the substrate surface structure.
Claim 6
Dependent Claim
76 words
In a method for the manufacture of a copper-alumina composite by electroless deposition of a copper layer into an alumina substrate, the improvement which comprises the step of acid etching vitreous grain boundaries of a working surface of said alumina substrate, prior to electroless deposition of the copper thereon, to a depth equal to at least about the diameter of an average grain at the working surface while maintaining a monolithic working surface of the substrate.
Claim 7
Dependent Claim
76 words
In a method for the manufacture of a copper-alumina composite by electroless deposition of a copper layer into an alumina substrate, the improvement which comprises the step of acid etching vitreous grain boundaries of a working surface of said alumina substrate, prior to electroless deposition of the copper thereon, to a depth equal to at least about the diameter of an average grain at the working surface while maintaining a monolithic working surface of the substrate.
Claim 8
Dependent Claim
38 words
The improvement in accordance with claim 5 wherein said acid etching is carried out to a depth greater than the diameter of an average grain at the working surface while maintaining a monolithic working surface of the substrate.
Claim 9
Dependent Claim
24 words
The improvement in accordance with claim 5 wherein said acid etching is carried out with an aqueous phosphoric acid solution at an elevated temperature.
Claim 10
Dependent Claim
23 words
The improvement in accordance with claim 7 wherein the elevated temperature is at about the boiling temperature of the aqueous phosphoric acid solution.
Claim 11
Dependent Claim
130 words
In a method for the manufacture of a metalceramic composite by a sensitizer/activator electroless metal deposition process, the improvement which comprises the steps of (a) acid etching a working surface of said ceramic, (b) contacting the resulting, acid-etched ceramic surface with an alkaline, palladium ion-containing activator solution wherein the palladium ion concentration is less than about 200 parts per million for a time period sufficient to deposit palladium ions thereon, (c) reducing the deposited palladium ions to palladium metal on said surface, (d) depositing by electroless deposition a layer of conductive metal onto said palladium metal-bearing surface, and (e) thereafter firing the produced metal-ceramic composite at a temperature sufficient to melt a portion of the metallic composition present at the interface of the deposited metal layer and the acid-etched surface.
Claim 12
Dependent Claim
130 words
In a method for the manufacture of a metalceramic composite by a sensitizer/activator electroless metal deposition process, the improvement which comprises the steps of (a) acid etching a working surface of said ceramic, (b) contacting the resulting, acid-etched ceramic surface with an alkaline, palladium ion-containing activator solution wherein the palladium ion concentration is less than about 200 parts per million for a time period sufficient to deposit palladium ions thereon, (c) reducing the deposited palladium ions to palladium metal on said surface, (d) depositing by electroless deposition a layer of conductive metal onto said palladium metal-bearing surface, and (e) thereafter firing the produced metal-ceramic composite at a temperature sufficient to melt a portion of the metallic composition present at the interface of the deposited metal layer and the acid-etched surface.
Claim 13
Dependent Claim
21 words
The improvement in accordance with claim 9 wherein the palladium ion concentration in said solution is about 150 parts per million.
Claim 14
Dependent Claim
63 words
The improvement in accordance with claim 9 wherein the acid etching of the ceramic surface is carried out for a time period sufficient to etch vitreous grain boundaries present at the working surface of the substrate to a depth equal to at least about the diameter of an average grain at the working surface while maintaining a monolithic working surface of the substrate.
Claim 15
Dependent Claim
60 words
The improvement in accordance with claim 9 wherein the acid etching of the ceramic surface is carried out for a time period sufficient to etch vitreous grain boundaries present at the working surface of the substrate to a depth greater than the diameter of an average grain at the working surface while maintaining a monolithic working surface of the substrate.
Claim 16
Dependent Claim
19 words
The improvement in accordance with claim 9 wherein the ceramic is alumina and wherein the conductive metal is copper.
Claim 17
Dependent Claim
23 words
The improvement in accordance with claim 13 wherein the firing is carried out at temperature of about 1060° C. to about 1075° C.
Claim 18
Dependent Claim
19 words
The improvement in accordance with claim 9 wherein the ceramic is beryllia and wherein the conductive metal is copper.
Claim 19
Dependent Claim
20 words
The improvement in accordance with claim 9 wherein the ceramic is aluminum nitride and wherein the conductive metal is copper.
Claim 20
Dependent Claim
148 words
In a method for the manufacture of a metal-ceramic composite by a sensitizer/activator electroless metal deposition process, the improvement which comprises the steps of (a) acid etching a working surface of said ceramic, (b) contacting the resulting, acid-etched ceramic surface with an alkaline, palladium ion-containing activator solution wherein the palladium ion concentration is less than about 200 parts per million for a time period sufficient to deposit palladium ions thereon, (c) reducing the deposited palladium ions to palladium metal on said surface, (d) depositing by electroless deposition a layer of conductive metal onto said palladium metal-bearing surface, (e) depositing by electrolytic deposition additional conductive metal onto said layer of conductive metal deposited by electroless deposition, and (f) thereafter firing the produced metal-ceramic composite at a temperature sufficient to melt a portion of the metallic composition present at the interface of the deposited metal layer and the acid-etched surface.
Claim 21
Dependent Claim
148 words
In a method for the manufacture of a metal-ceramic composite by a sensitizer/activator electroless metal deposition process, the improvement which comprises the steps of (a) acid etching a working surface of said ceramic, (b) contacting the resulting, acid-etched ceramic surface with an alkaline, palladium ion-containing activator solution wherein the palladium ion concentration is less than about 200 parts per million for a time period sufficient to deposit palladium ions thereon, (c) reducing the deposited palladium ions to palladium metal on said surface, (d) depositing by electroless deposition a layer of conductive metal onto said palladium metal-bearing surface, (e) depositing by electrolytic deposition additional conductive metal onto said layer of conductive metal deposited by electroless deposition, and (f) thereafter firing the produced metal-ceramic composite at a temperature sufficient to melt a portion of the metallic composition present at the interface of the deposited metal layer and the acid-etched surface.
Claim 22
Dependent Claim
34 words
The improvement in accordance with claim 17 wherein said additional conductive metal is deposited so as to provide an increasing density gradient in the deposited metal in the direction away from said working surface.
Claim 23
Dependent Claim
18 words
The improvement in accordance with claim 18 wherein said conductive metal is copper and said ceramic is alumina.
Claim 24
Dependent Claim
24 words
The improvement in accordance with claim 19 wherein said firing is carried out at a temperature of about 1066° C. to about 1075° C.
Claim 25
Dependent Claim
18 words
The improvement in accordance with claim 18 wherein said conductive metal is copper and said ceramic is beryllia.
Claim 26
Dependent Claim
19 words
The improvement in accordance with claim 18 wherein said conductive metal is copper and said ceramic is aluminum nitride.
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1994-10-21 | 1995-04-22 | 1995-10-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-10-21 | 1999-04-22 | 1999-10-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-10-21 | 2003-04-22 | 2003-10-22 | $7700.00 | Window Closed / Lapsed |