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US3624460A Expired / Lapsed US ⏱️ 0.0 years remaining

Electrolytic capacitor employing glass-to-metal hermetic seal

Assignee: General Electric Co
•
Filing: 1969-12-29
•
Granted: 1971-11-30
•
Expires: 1989-12-29
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Abstract

Abstract An electrolytic capacitor is provided having a metal-to-glass hermetic seal assembly wherein a glass body containing an effective amount of chromic oxide is directly bonded outwardly and inwardly to a film-forming metal such as tantalum. The glass has a mean thermal coefficient of expansion which is not greater than that of the metal of the seal and does not differ therefrom substantially over a wide temperature range, thus resulting in a substantially matched or slight compression type of seal. All components of the seal exposed to contact with the electrolyte are resistant to sulfuric acid. In one embodiment, utilizing an all-welded tantalum case, a substantial reverse voltage capability is made possible. A fluorocarbon spacer ring separating the porous anode from the casing wall and a thin ceramic heat shield for protection of the anode during welding assembly of the case also provide a cushioning effect for vibration and shock resistance.

Inventors

  • 👤 Edward M Correll

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-09 13:37
CPC Classifications
C; C03; C03C; C03C29/00; H; H01; H01G; H01G9/00; H01G9/004; H01G9/08; H01G9/10

Claims Analysis

Total Claims: 9
Claim 1
Independent Claim 37 words
A capacitor according to claim 1, said closure including metal means of tantalum fusion-bonded to the glass of the closure, said casing forming one of said metal means, whereby the capacitor has a substantial reverse voltage capability.
Claim 2
Dependent Claim 33 words
a coefficient of thermal expansion not greater than that of tantalum and differing therefrom by not more than about 15 X 107 cm./cm./*C. over a temperature range of 0* to 300* C; and
Claim 3
Dependent Claim 36 words
an approximate composition of from: 63-65 SiO2, 2 to 3% A12O3, 2 to 3% Na2O, 6 to 8% K2O, 0 to 2% CaO, 4 to 6% BaO, 0.2 to 1.0% Cr2O3, and 15 to 17% B2O3.
Claim 4
Dependent Claim 40 words
An assembly according to claim 2, further including a ceramic shield disk member disposed between said porous anode and the bottom end of the casing, said ceramic member being of a material substantially immune from attack by said sulfuric acid.
Claim 5
Dependent Claim 21 words
An assembly according to claim 1, further including spacer ring means around said porous anode to insulate same from said casing.
Claim 6
Dependent Claim 91 words
An electrolytic capacitor comprising: a. a tantalum cathode casing having at least one open end; b. a sulfuric acid electrolyte in said casing; c. a porous anode of sintered tantalum having a dielectric film thereon in said casing and immersed in said electrolyte said anode having a terminal lead extending through said one open end; and d. a tantalum-to-glass-to-tantalum closure hermetically sealing said one open end, said closure consisting essentially of an annular glass member fusion bonded to inner and outer tantalum metal means and having a glass composition characterized by:
Claim 7
Dependent Claim 31 words
An assembly according to claim 5, said inner metal means including a terminal lead of tantalum extending outwardly from said electrical component and passing through said end opening of the casing.
Claim 8
Dependent Claim 50 words
An assembly according to claim 5, said inner metal means including an eyelet tube of tantalum passing through and fusion bonded to said glass material, and a terminal lead of tantalum within said tube extending outwardly from said electrical component and sealed to the outer end of said eyelet tube.
Claim 9
Dependent Claim 20 words
An assembly according to claim 5, said outer metal means comprising a header ring of tantalum fixed to said casing.

References Cited (Backward Citations)

US3275359A Cited
US3275358A Cited
US3275901A Cited
US3370874A Cited
US3461355A Cited
US3515950A Cited
US3515951A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1974-11-29 1975-05-31 1975-11-30 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1978-11-29 1979-05-31 1979-11-30 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1982-11-29 1983-05-31 1983-11-30 $7700.00 Window Closed / Lapsed

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