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
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 17 to 26 weight percent;
Al 2 O 3 in an amount from 13 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 from 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 from 0 to 1 weight percent;
CeO 2 in an amount less than 0.2 weight percent; and
BaO in an amount less than 0.1 weight percent.
2 . The composition of claim 1 , wherein the B 2 O 3 content is from 17.5 to 25 weight percent.
3 . The composition of claim 1 , wherein the MgO content is from greater than 0 to 7.5 weight percent.
4 . The composition of claim 1 , wherein the MgO content is from 2 to 8.5 weight percent.
5 . The composition of claim 1 , wherein the CaO content is from greater than 0 to 5.5 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 Li 2 O content is from greater than 0 to 0.8 weight percent.
8 . The composition of claim 1 , wherein the F 2 content is from greater than 0 to 1.5 weight percent.
9 . The composition of claim 1 , wherein the TiO 2 content is from greater than 0 to 0.7 weight percent.
10 . The composition of claim 1 , wherein the ZnO content is from greater than 0 to 5 weight percent.
11 . The composition of claim 1 , wherein the Fe 2 O 3 content is from greater than 0 to 0.5 weight percent.
12 . The composition of claim 1 , wherein the composition is substantially free from SrO.
13 . The composition of claim 1 , wherein the MgO+CaO content is 9 weight percent or less.
14 . The composition of claim 1 , wherein the MgO+CaO content is from greater than 0 to 9 weight percent.
15 . The composition of claim 1 , wherein the Al 2 O 3 +MgO content is from 14 to 26 weight percent.
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 Al 2 O 3 +ZnO content is from 14 to 22 weight percent.
18 . A fiber formed from the composition of claim 1 .
19 . An article of manufacture comprising the fiber of claim 18 .
20 . The article of manufacture of claim 19 , wherein the article is a printed circuit board.