Use of MgO, ZnO, and rare earth oxides for making improved low dielectric fibers with improved low thermal expansion coefficient for high boron aluminosilicate compositions
View Patent ↗New glass compositions and applications thereof are disclosed. A glass composition as described herein can include 50 to 55 weight percent SiO 2 , 17 to 26 weight percent B 2 O 3 , 13 to 19 weight percent Al 2 O 3 , 0 to 8.5 weight percent MgO, 0 to 7.5 weight percent ZnO, 0 to 6 weight percent CaO, 0 to 1.5 weight percent Li 2 O, 0 to 1.5 weight percent F 2 , 0 to 1 weight percent Na 2 O, 0 to 1 weight percent Fe 2 O 3 , 0 to 1 weight percent TiO 2 , and 0 to 8 weight percent of other constituents. Also described herein are glass fibers formed from such compositions, composites, and articles of manufacture comprising the glass compositions and/or glass fibers.
1. A glass composition suitable for fiber forming comprising:
SiO 2 in an amount from 50 to 55 weight percent;
B 2 O 3 in an amount from greater than 20 to 25 weight percent;
Al 2 O 3 in an amount from greater than 14 to 19 weight percent;
MgO in an amount from 0 to 8.5 weight percent;
ZnO in an amount from 0 to 7.5 weight percent;
CaO in an amount from 0 to 6 weight percent;
Li 2 O in an amount from 0 to 1.5 weight percent;
F 2 in an amount greater than 0 to 1.5 weight percent;
Na 2 O in an amount from 0 to 1 weight percent;
Fe 2 O 3 in an amount from 0 to 1 weight percent;
TiO 2 in an amount greater than 0 to 1 weight percent; and
one or more rare earth oxides (RE 2 O 3 ) in an amount from 0 to 8 weight percent total,
wherein the composition is substantially free of SrO.
2. The composition of claim 1 , wherein the SiO 2 content is from 51 to 54 weight percent.
3. The composition of claim 1 , wherein the MgO content is from 2 to 8.5 weight percent.
4. The composition of claim 1 , wherein the ZnO content is from greater than 0 to 5 weight percent.
5. The composition of claim 1 , wherein the Na 2 O content is from greater than 0 to 0.5 weight percent.
6. The composition of claim 1 , wherein the Li 2 O content is 0.8 weight percent or less.
7. The composition of claim 1 , wherein the Fe 2 O 3 content is from greater than 0 to 0.5 weight percent.
8. The composition of claim 1 , wherein the TiO 2 content is from greater than 0 to 0.6 weight percent.
9. The composition of claim 1 , wherein the glass composition comprises one or more rare earth oxides in an amount greater than 0.01 weight percent.
10. The composition of claim 1 , wherein the one or more rare earth oxides content is from greater than 0 to 7 weight percent.
11. The composition of claim 1 , wherein the one or more rare earth oxides comprise at least one of La 2 O 3 , CeO 2 , Y 2 O 3 and Sc 2 O 3 in an amount of 0 to 8 weight percent total.
12. The composition of claim 1 , wherein the composition is substantially free from BaO.
13. The composition of claim 1 , wherein the Al 2 O 3 +MgO content is from 14 to 26.5 weight percent.
14. The composition of claim 1 , wherein the Al 2 O 3 +ZnO content is from 14 to 22 weight percent.
15. The composition of claim 1 , wherein the MgO +CaO content is 9 weight percent or less.
16. The composition of claim 1 , wherein the total Na 2 O+Li 2 O content is 1.5 weight percent or less.
17. The composition of claim 1 , wherein the RE 2 O 3 +Al 2 O 3 content is from 13 to 22 weight percent.
18. A fiber formed from a composition of claim 1 .
19. An article of manufacture comprising a fiber of claim 18 .
20. The article of manufacture of claim 19 , wherein the article is a printed circuit board.