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US5277946A Expired / Lapsed US ⏱️ 0.0 years remaining

Alumina package for hermetically containing an electronic device therein

Assignee: Nippon Electric Glass Co Ltd
•
Filing: 1992-09-01
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Granted: 1994-01-11
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Expires: 2012-09-01
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Abstract

Abstract In a borosilicate glass plate containing Li 2 O, Na 2 O and K 2 O and for use as a window plate in an alumina package for containing a semiconductor device, Li + and Na + ions are partially ion-exchanged by K + ions in a surface of the glass plate to form a surface layer having a compressive stress of 200 Kg.f/cm 2 or more, in order to make a thin window glass plate for the package having a thickness of 0.7 mm or less and a sufficient mechanical strength. The glass also has a thermal expansion coefficient of 50-75×10 -7 /° C. over a temperature range of 30°-380° C. so as to be thermally compatible with the alumina package. The glass consists essentially of SiO 2 55-64%, Al 2 O 3 7-20%, B 2 O 3 11-19%, Li 2 O 0-8%, Na 2 O 7-20%, K 2 O 0-4%, and RO 0.5-7% on the base of weight percent, where R is at least one of Mg, Ca, Sr, and Ba. In order to insure the ion exchange, amounts of Li 2 O, Na 2 O and K 2 O are adjusted so that (Li 2 O+Na 2 O/(Li 2 O+Na 2 O+K 2 O) is 0.7 or more.

Inventors

  • 👤 Hiroki Nagai
  • 👤 Shigeru Yamamoto

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-30 07:33
CPC Classifications
C; C03; C03C; C03C21/00; C03C21/001; C03C21/002; C03C3/00; C03C3/04; C03C3/076; C03C3/089; C03C3/091; Y; Y10; Y10S; Y10S501/00; Y10S501/90; Y10S501/905; Y10T; Y10T428/00; Y10T428/23; Y10T428/239; Y10T428/31; Y10T428/315

Claims Analysis

Total Claims: 3
Claim 1
Independent Claim 222 words
A package for hermetically containing an electronic device therein, said package comprising: an alumina base plate on which said electronic device can be mounted; and a glass plate window mounted to said alumina base plate so as to hermetically contain said electronic device, said glass plate window having a thickness of 0.7 mm or less, a thermal expansion coefficient in the range of about 50×10 -7 /° C. to about 75×10 -7 /° C. over a temperature range from about 30° C. to about 380° C., and a transmission of 40% or more through 1 mm thickness of said glass plate window for ultraviolet radiation having a wavelength of 253.7 nanometers, said glass plate window being free from ZnO and consisting essentially of SiO 2 55-64%, Al 2 O 3 7-20%, B 2 O 3 11.5-14%, Li 2 O 0-8%, Na 2 O 7-20%, K 2 O 0-4% and RO 0.5-7% on the basis of weight percent, R being at least one of Mg, Ca, Sr, and Ba, and said glass plate window having a surface layer in which alkaline metal ions are partially ion-exchanged with another alkaline metal ion having an ion radius larger than that or said first mentioned alkaline metal ions, so as to provide said surface layer with a compressive stress of at least 200 Kg.f/cm 2 .
Claim 2
Dependent Claim 222 words
A package for hermetically containing an electronic device therein, said package comprising: an alumina base plate on which said electronic device can be mounted; and a glass plate window mounted to said alumina base plate so as to hermetically contain said electronic device, said glass plate window having a thickness of 0.7 mm or less, a thermal expansion coefficient in the range of about 50×10 -7 /° C. to about 75×10 -7 /° C. over a temperature range from about 30° C. to about 380° C., and a transmission of 40% or more through 1 mm thickness of said glass plate window for ultraviolet radiation having a wavelength of 253.7 nanometers, said glass plate window being free from ZnO and consisting essentially of SiO 2 55-64%, Al 2 O 3 7-20%, B 2 O 3 11.5-14%, Li 2 O 0-8%, Na 2 O 7-20%, K 2 O 0-4% and RO 0.5-7% on the basis of weight percent, R being at least one of Mg, Ca, Sr, and Ba, and said glass plate window having a surface layer in which alkaline metal ions are partially ion-exchanged with another alkaline metal ion having an ion radius larger than that or said first mentioned alkaline metal ions, so as to provide said surface layer with a compressive stress of at least 200 Kg.f/cm 2 .
Claim 3
Dependent Claim 23 words
The package of claim 1, wherein the ratio (Li 2 O+Na 2 O))/(Li 2 O+Na 2 O+K 2 O) is 0.7 or more.

References Cited (Backward Citations)

US3506423A Cited
US4089694A Cited
US4417913A Cited
US4839313A Cited
JPS6265954A Cited
JPS6414185A Cited
US4792535A Cited
US5045509A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1997-01-10 1997-07-12 1998-01-11 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2001-01-10 2001-07-12 2002-01-11 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2005-01-10 2005-07-12 2006-01-11 $7700.00 Window Closed / Lapsed

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