US 12,466,761 B2
Low temperature co-fired substrate composition
Keito Sato, Kashiwa (JP); and Nobuhito Takeshima, Kashiwa (JP)
Assigned to Okamoto Glass Co., Ltd., Kashiwa (JP)
Appl. No. 17/802,528
Filed by Okamoto Glass Co., Ltd., Kashiwa (JP)
PCT Filed May 17, 2021, PCT No. PCT/JP2021/018539
§ 371(c)(1), (2) Date Aug. 26, 2022,
PCT Pub. No. WO2022/054337, PCT Pub. Date Mar. 17, 2022.
Claims priority of application No. 2020-153478 (JP), filed on Sep. 14, 2020.
Prior Publication US 2023/0096796 A1, Mar. 30, 2023
Int. Cl. C03C 3/089 (2006.01); C03C 4/16 (2006.01); C03C 12/00 (2006.01); C03C 14/00 (2006.01); C03C 17/06 (2006.01)
CPC C03C 3/089 (2013.01) [C03C 4/16 (2013.01); C03C 12/00 (2013.01); C03C 14/004 (2013.01); C03C 17/06 (2013.01); C03C 2214/04 (2013.01); C03C 2217/256 (2013.01)] 1 Claim
OG exemplary drawing
 
1. A low temperature co-fired substrate composition before a co-firing process, comprising:
(A) 83 to 91 wt. % of glass powder containing CaO—B2O3—SiO2 as a basic composition;
(B) 7.5 to 14 wt. % of SiO2 powder; and
(C) 1.5 to 3 wt. % of β-wollastonite (CaSiO3) powder, wherein
a particle diameter D50 of the glass powder (A) is 2.0 to 3.0 μm,
the glass powder (A) contains 40.0 to 45.0 wt. % of CaO, 9.0 to 20.0 wt. % of B2O3 and 40.0 to 46.0 wt. % of SiO2 as a composition,
the SiO2 powder (B) is a filler selected from the group consisting of (1), (2) and (3):
(1) 10 to 30 wt. % of the SiO2 powder having the particle diameter D50 of 10 to 100 nm and 70 to 90 wt. % of the SiO2 powder having the particle diameter D50 of 400 to 3000 nm;
(2) 60 wt. % or more of the SiO2 powder having the particle diameter D50 of 100 to 400 nm and less than 40 wt. % of the SiO2 powder having the particle diameter D50 of 400 to 3000 nm; and
(3) 4 to 20 wt. % of the SiO2 powder having the particle diameter D50 of 10 to 100 nm, 60 to 95 wt. % of the SiO2 powder having the particle diameter D50 of 100 to 400 nm and 0 to 36 wt. % of the SiO2 powder having the particle diameter D50 of 400 to 3000 nm,
the β-wollastonite (CaSiO3) powder (C) is another filler having the particle diameter D50 of 2.0 to 3.0 μm,
when a silver paste, which functions as an electrode, is applied on a surface of a green sheet comprised of the low temperature co-fired substrate before the co-firing process and an organic binder and the co-firing process is performed, the low temperature co-fired substrate after the co-firing process has the following properties:
a relative permittivity k is 6.0 or less at 2.5 GHz;
a Q value which is a reciprocal of dielectric tangent is 500 or more at 2.5 GHz; and
a ratio R420/R800 of a reflectance R420 in a wavelength of 420 nm with respect to a reflectance R800 in the wavelength of 800 nm is 85% or more.