Claims
- 1. The method of bonding an electronic device to a ceramic substrate comprising:
- applying a silver-filled glass metallizing composition onto said substrate, said glass consisting essentially of:
- 25 to 95% of silver powder having a surface area of about 0.2 to 1.0 m.sup.2 /gm and a tap density of about 2.2 to 2.8 gm/cc;
- 75 to 5% of high-lead, borosilicate substantially sodium-free glass frit having a softening temperature in the range of 325.degree. to 425.degree. C., a coefficient of thermal expansion no higher than about 13 ppm/.degree.C., a surface area in the range of about 0.3 to 0.6 m.sup.2 /gm, and a tap density in the range of about 2.8 to 3.6 gm/cc;
- a suitable liquid organic vehicle in an amount sufficient to establish the percent solids in said paste in the range of about 75 to 85%;
- setting said device into said metallizing composition with pressure to form an assembly;
- drying said assembly;
- firing said assembly at a peak temperature in the range of 425.degree. to 525.degree. C.
- 2. The method as claimed in claim 1, wherein said glass comprises about 95% PbO.
- 3. The method as claimed in claim 1, wherein the silver:glass ratio in said metallizing composition is about 80:20.
- 4. The method as claimed in claim 1, wherein said glass consists essentially of:
- PbO: 95-96%
- SiO.sub.2 : 0.5-2.5%
- B.sub.2 O.sub.3 : remainder.
- 5. The method as claimed in claim 1, wherein said electronic device is a silicon die.
- 6. The method as claimed in claim 1, wherein said electronic device is a chip capacitor.
- 7. The method as claimed in claim 1, wherein a portion of the silver in said metallizing composition is replaced by a metal selected from the group consisting of nickel, tin and copper, up to the following limits:
- Ni: up to 10%
- Sn: up to 60%
- Cu: up to 20%.
RELATED APPLICATIONS
This application is a division of application Ser. No. 355,719, filed Mar. 8, 1982, now U.S. Pat. No. 4,401,768 issued Aug. 30, 1983 which was a continuation-in-part of application Ser. No. 287,892, filed Aug. 3, 1981, now abandoned.
US Referenced Citations (15)
Foreign Referenced Citations (4)
Number |
Date |
Country |
8782 |
Mar 1980 |
EPX |
3301 |
Jan 1882 |
GBX |
625466 |
Jun 1949 |
GBX |
792293 |
Dec 1980 |
SUX |
Non-Patent Literature Citations (3)
Entry |
Greenwood, R. W., "Silver Bearing Conductive Pastes", IBM Tech. Discl. Bulletin, Jul. 1974, 17, (2), p. 437. |
Geller, R. F. et al., Some "Soft" Glazes of Low Thermal Expansion-J. of Research of National Bur. of Stand., 20 Jan. 1938, p. 61, Res. Paper 1064, Density Measurements of Powders used in Paste for the Microelectronics Industry. |
Scramaglia, R., "Powder Properties Affect Fired Film" Ceramic Industry, 119 (5), Nov. 1982, pp. 44-46. |
Divisions (1)
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Number |
Date |
Country |
Parent |
355719 |
Mar 1982 |
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Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
287892 |
Aug 1981 |
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