Glass substrate for high-frequency device and circuit board for high-frequency device

Patent metadata

Field	Value
Publication number	US-10974987-B2
Application number	US-201916351007-A
Country	US
Kind code	B2
Filing date	Mar 12, 2019
Priority date	Sep 13, 2016
Publication date	Apr 13, 2021
Grant date	Apr 13, 2021

Abstract

The present invention relates to a glass substrate for a high-frequency device, which includes SiO2 as a main component, the glass substrate having a total content of alkali metal oxides in the range of 0.001-5% in terms of mole percent on the basis of oxides, the alkali metal oxides having a molar ratio represented by Na2O/(Na2O+K2O) in the range of 0.01-0.99, and the glass substrate having a total content of Al2O3 and B2O3 in the range of 1-40% in terms of mole percent on the basis of oxides and having a molar ratio represented by Al2O3/(Al2O3+B2O3) in the range of 0-0.45, in which at least one main surface of the glass substrate has a surface roughness of 1.5 nm or less in terms of arithmetic average roughness Ra, and the glass substrate has a dielectric dissipation factor at 35 GHz of 0.007 or less.

First claim

The invention claimed is:

1. A glass substrate, which comprises SiO 2 as a main component, the glass substrate having a total content of alkali metal oxides in the range of 0.001-5% in terms of mole percent on the basis of oxides, the alkali metal oxides having a molar ratio represented by Na 2 O/(Na 2 O+K 2 O) in the range of 0.01-0.99, and the glass substrate having a total content of Al 2 O 3 and B 2 O 3 in the range of 16-40% in terms of mole percent on the basis of oxides and having a molar ratio represented by Al 2 O 3 /(Al 2 O 3 +B 2 O 3 ) in the range of 0-0.45,
wherein the glass substrate comprises, in terms of mole percent on the basis of oxides:
SiO 2 40-75%;
Al 2 O 0-15%;
B 2 O 3 16-30%;
MgO 0-13%;
CaO 0-13%;
SrO 3-13%;
BaO 0-10%,
wherein at least one main surface of the glass substrate has a surface roughness of 1.5 nm or less in terms of arithmetic average roughness Ra, and the glass substrate has a dielectric dissipation factor at 35 GHz of 0.007 or less.

2. The glass substrate according to claim 1 , which has a content of Al 2 O 3 in the range of 0-10%, in terms of mole percent on the basis of oxides.

3. The glass substrate according to claim 1 , which has a content of Fe, in terms of Fe 2 O 3 , of 0.012% or less in terms of mole percent on the basis of oxides.

4. The glass substrate according to claim 1 , which has a β-OH value in the range of 0.05-0.6 mm −1 .

5. The glass substrate according to claim 1 , which has a relative permittivity at 35 GHz of 10 or less.

6. The glass substrate according to claim 1 , which has an average thermal expansion coefficient over the range of from 50° C. to 350° C. in the range of 3-15 ppm/° C.

7. The glass substrate according to claim 1 , which has a Young's modulus of 40 GPa or higher.

8. The glass substrate according to claim 1 , which has a porosity of 0.1% or less.

9. The glass substrate according to claim 1 , which has a transmittance at 350-nm wavelength of 50% or higher.

10. The glass substrate according to claim 1 , which has a thickness in the range of 0.05-1 mm and a substrate area in the range of 225-10,000 cm 2 .

11. The glass substrate according to claim 1 , which is amorphous.

12. A circuit board for a high-frequency device, comprising:
the glass substrate according to claim 1 ; and
a wiring layer formed on the main surface of the glass substrate,
wherein the circuit board has a transmission loss at 35 GHz of 1 dB/cm or less.

13. The glass substrate according to claim 1 , which has a content of B 2 O 3 in the range of 16-24%, in terms of mole percent on the basis of oxides.

14. The glass substrate according to claim 1 , which has a content of B 2 O 3 in the range of 16-23%, in terms of mole percent on the basis of oxides.

15. The glass substrate according to claim 1 , which has a content of CaO in the range of 0-5%, in terms of mole percent on the basis of oxides.

Assignees

• Agc Inc

Inventors

• Ono Kazutaka
• Nomura Shuhei
• Kidera Nobutaka
• Takeshita Nobuhiko

Classifications

• C03B17/064

  by the overflow downdraw fusion process; Isopipes therefor · CPC title

• C03B17/02

  Forming {molten} glass coated with coloured layers; {Forming molten glass of different compositions or layers; Forming molten glass comprising reinforcements or inserts} · CPC title

• C03B19/14 Primary

  by gas- {or vapour-} phase reaction processes · CPC title

• C03B25/08

  of glass sheets · CPC title

• H05K1/0306

  Inorganic insulating substrates, e.g. ceramic, glass · CPC title