High-expansion bonding glass having improved water resistance and uses thereof
The present disclosure relates to a bonding glass which has improved water resistance and has a coefficient of thermal expansion α(25-300) of from 14·10 −6 K −1 to 17·10 −6 K −1 , comprising, in mol % on an oxide basis, 5-7 of B 2 O 3 , 10-14 of Al 2 O 3 , 36-43 of P 2 O 5 , 15-22 of Na 2 O, 12.5-20 of K 2 O, 2-6 of Bi 2 O 3 and >0-6 of R oxide, where R oxide is an oxide selected from the group consisting of MnO 2 and SiO 2 and SnO 2 and Ta 2 O 5 and Nb 2 O 5 and Fe 2 O 3 and GeO 2 and CaO. The bonding glass is free of PbO except for, at most, impurities. The bonding glass may have a glass transition temperature Tg of from 390° C. to 430° C. The present disclosure also relates to uses of this bonding glass.
1. A bonding glass which has a coefficient of thermal expansion α(25-300) of from 14·10 −6 K −1 to 17·10 −6 K −1 , comprising a composition in mol % on an oxide basis of:
B 2 O 3
4-8;
Al 2 O 3
10-14;
P 2 O 5
36-43;
Na 2 O
15-22;
K 2 O
12.5-20;
Bi 2 O 3
2-6; and
R oxide
>0-6,
wherein R oxide is an oxide selected from the group consisting of MnO 2 , SiO 2 , SnO 2 , Ta 2 O 5 , Nb 2 O 5 , Fe 2 O 3 , GeO 2 , CaO, and combinations thereof, the composition being free of PbO except for, at most, impurities.
2. The bonding glass according to claim 1 , wherein the bonding glass has a glass transition temperature Tg of from 390° C. to 430° C.
3. The bonding glass according to claim 1 , wherein R oxide comprises, in mol % on an oxide basis, 3.0-6.0 MnO 2 .
4. The bonding glass according to claim 3 , wherein R oxide comprises, in mol % on an oxide basis, 3.2-4.9 MnO 2.
5. The bonding glass according to claim 1 , wherein R oxide comprises, in mol % on an oxide basis, at least one of the following oxides:
SiO 2
0.01-1.8;
GeO 2
0.01-2.8;
SnO 2
0.01-2.4;
Fe 2 O 3
0.01-2.1;
Ta 2 O 5
0.01-2.2;
Nb 2 O 5
0.01-2.0; and
CaO
0.01-0.4.
6. The bonding glass according to claim 1 , wherein the composition comprises, in mol % on an oxide basis, at least one of the following oxides:
P 2 O 5
36-<42;
B 2 O 3
5.5-6.8;
Al 2 O 3
11.4-12.8;
Na 2 O
15.4-20.9;
K 2 O
12.8-19.8; and
Bi 2 O 3
2.5-4.5.
7. The bonding glass according to claim 1 , wherein the composition comprises at least one additional alkali metal oxide, other than Na 2 O and K 2 O, and a total content of alkali metal oxides in the composition is at most 36 mol %.
8. The bonding glass according to claim 7 , wherein the at least one additional alkali metal oxide is selected from the group consisting of Li 2 O, Cs 2 O, and combinations thereof.
9. The bonding glass according to claim 1 , wherein the bonding glass has crystalline regions which comprise phosphate-containing crystal phases.
10. The bonding glass according to claim 9 , wherein the crystal phases comprise crystals from the group consisting of a Bi 2 O 3 —P 2 O 5 system, an R 2 O—Al 2 o 3 —P 2 O 5 system, and combinations thereof.
11. The bonding glass according to claim 10 , wherein the crystal phases comprise crystals from a K 2 O—Al 2 O 3 —P 2 O 5 system.
12. The bonding glass according to claim 1 , wherein the composition is in the form of a glass powder.
13. The bonding glass according to claim 1 , further comprising a metal bonded to the bonding glass to form a glass-metal composite.
14. The glass-metal composite according to claim 13 , wherein the metal is one of a lightweight metal and a lightweight metal alloy.
15. The glass-metal composite according to claim 13 , wherein the metal is selected from the group consisting of aluminum, aluminum alloys, titanium, titanium alloys, magnesium, magnesium alloys, AlSiC, steel, stainless steel, copper, copper alloys, and combinations thereof.
16. The glass-metal composite according to claim 13 , wherein the bonding glass is covered, at least in sections, by a covering glass or a covering polymer.
17. The glass-metal composite according to claim 16 , wherein the bonding glass is covered, at least in sections, by a covering glass having a higher water resistance than the bonding glass and comprising a titanate glass.
18. A device, comprising:
a feedthrough, comprising:
at least one main element composed of a metal and which has at least one opening formed therethrough;
a functional element passed through the at least one opening and embedded in a bonding glass in the at least one opening, the bonding glass seals the at least one opening, the bonding glass having a coefficient of thermal expansion α(25-300) of from 14·10 −6 K −1 to 17·10 −6 K −1 , the bonding glass comprising a composition in mol % on an oxide basis of:
B 2 O 3
4-8;
Al 2 O 3
10-14;
P 2 O 5
36-43;
Na 2 O
15-22;
K 2 O
12.5-20;
Bi 2 O 3
2-6; and
R oxide
>0-6,
wherein R oxide is an oxide selected from the group consisting of MnO 2 , SiO 2 , SnO 2 , Ta 2 O 5 , Nb 2 O 5 , Fe 2 O 3 , GeO 2 , CaO, and combinations thereof, the composition being free of PbO except for, at most, impurities.
19. The device according to claim 18 , wherein the bonding glass hermetically seals the at least one opening.
20. The device according to claim 18 , wherein the functional element is, at least in a region of the at least one opening, a pin-shaped conductor.
21. The device according to claim 20 , wherein the pin-shaped conductor comprises, at least in the region of the at least one opening, at least one of copper and aluminum.
22. The device according to claim 18 , wherein the metal is at least one of a lightweight metal and a lightweight metal alloy.
23. The device according to claim 18 , further comprising a housing holding the at least one feedthrough.
24. The device according to claim 23 , wherein the housing comprises a metal bonded to the bonding glass to form a glass-metal composite.
25. The device according to claim 18 , wherein the device is at least one of an electrical device, an electronic device, or an electrochemical device selected from the group consisting of batteries, rechargeable batteries, capacitors, supercapacitors, sensor housings, actuator housings, microcontroller housings, medical implants, articles configured to be installed on a human body or an animal body, diagnostic instruments, and therapeutic instruments.