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Glass compositions with low dielectric losses
| Details |
Inventors: Sack, Werner;
Assignee: Schott Glaswerke (Mainz, DE)
Primary Examiner:
Assistant Examiner:
Attorney, Agent or Firm:
Alkali-free glasses with low dielectric losses, thermal expansion coefficients of 3.15 to 4.97.times.10.sup.-6 /.degree.C. in the temperature range from 20.degree. to 300.degree. C., adequate acid resistance, dielectric loss factors tan .delta. of 3.94 to 24.9.times.10.sup.-4 and processing temperatures (V.sub.A) of 1132.degree. to 1280.degree. C., have the following composition (in weight percent): 52.50-60.20 SiO.sub.2, 2.80-3.80 B.sub.2 O.sub.3, 8-14 Al.sub.2 O.sub.3, 6.0-20.20 PbO, 2.0-13.5 CaO, 0-3.5 MgO, 0-8 ZnO, 0-4.7 BaO, .SIGMA.PbO, CaO, MgO, ZnO, BaO 21.10-34.0, 0-1.0 F, 0.20-0.50 Sb.sub.2 O.sub.3. |
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DETAILED DESCRIPTION What is claimed is: 1.
A glass consisting essentially of, in analysis oxide weight percent, SiO.
sub.
2 : 52.
50 to 60.
20 B.
sub.
2 O.
sub.
3 : 2.
80 to 3.
80 Al.
sub.
2 O.
sub.
3 : 8.
00 to 14.
00 PbO: 6.
00 to 20.
20 CaO: 2.
00 to 13.
50 MgO: 0 to 3.
50 ZnO: 0 to 8.
00 BaO: 0 to 4.
70 PbO+CaO+MgO+ZnO+BaO: 21.
10 to 34.
00 F: 0 to 1.
00 Sb.
sub.
2 O.
sub.
3 : 0.
20 to 0.
50 wherein 100 wt.
% is exclusive of Sb.
sub.
2 O.
sub.
3, and being essentially alkali metal-free and having the following properties: a thermal expansion coefficient in the temperature range from 20.
degree.
to 300.
degree.
C.
of 3.
15 to 4.
97.
times.
10.
sup.
-6 /.
degree.
C.
, an acid resistance whereby the glass falls within the third class or better in the acid-resistance table according to DIN 12116, a water stability whereby the glass falls within the first class or better in the water stability table according to DIN 12111, a T.
sub.
k100 value of >500.
degree.
C.
, a dielectric constant (.
epsilon.
)--measured at 50 and 500 Hz in each case at 20.
degree.
and 70.
degree.
C.
--of 5.
95 to 7.
02, a dielectric loss factor (tan .
delta.
)--also measured at 50 and 500 Hz at 20.
degree.
and 70.
degree.
C.
in each case--of 3.
94 to 24.
9.
times.
10.
sup.
-4, a transformation temperature (Tg) of 622.
degree.
to 663.
degree.
C.
, a softening temperature (Ew) of 849.
degree.
to 898.
degree.
C.
, a processing temperature (V.
sub.
A) of 1132.
degree.
to 1280.
degree.
C.
, and a density (D) of 2.
69 to 2.
992 g/cm.
sup.
3.
2.
A glass of claim 1 consisting essentially of, in analysis oxide weight percent, SiO.
sub.
2 : 52.
50 to 55.
70 B.
sub.
2 O.
sub.
3 : 3.
00 to 3.
80 Al.
sub.
2 O.
sub.
3 : 8.
00 to 14.
00 PbO: 13.
50 to 20.
20 CaO: 2.
00 to 13.
50 MgO: 0 to 3.
50 ZnO: 0 to 8.
00 BaO: 0 to 4.
70 PbO+CaO+MgO+ZnO+BaO: 30.
50 to 34.
00 Sb.
sub.
2 O.
sub.
3 : 0.
20 to 0.
50 and being essentially alkali metal- and fluorine-free and having the following properties: a thermal expansion coefficient of 3.
37-4.
97.
times.
10.
sup.
-6 /.
degree.
C.
in the temperature range from 20.
degree.
-300.
degree.
C.
, a dielectric constant (
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Manufacturing Materials 
