US 12,451,406 B2
Silicon nitride substrate and method of manufacturing the same
Rei Fukumoto, Tokyo (JP); Youichiro Kaga, Tokyo (JP); and Kei Shimada, Tokyo (JP)
Assigned to PROTERIAL, LTD., Tokyo (JP)
Filed by Proterial, Ltd., Tokyo (JP)
Filed on Feb. 23, 2023, as Appl. No. 18/173,146.
Claims priority of application No. 2022-027436 (JP), filed on Feb. 25, 2022.
Prior Publication US 2023/0275002 A1, Aug. 31, 2023
Int. Cl. H01L 23/34 (2006.01); H01L 21/48 (2006.01); H01L 23/373 (2006.01); H01L 25/07 (2006.01); H02P 27/06 (2006.01)
CPC H01L 23/3735 (2013.01) [H01L 21/4807 (2013.01); H01L 25/072 (2013.01); H02P 27/06 (2013.01)] 8 Claims
OG exemplary drawing
 
1. A silicon nitride substrate comprising:
a first surface; and
a second surface opposite to the first surface,
wherein a planar shape is rectangular, each side length of which is equal to or larger than 100 mm,
a thermal conductivity is equal to or higher than 110 W/(m·K),
when color difference between a center and an edge of at least one surface of the first surface and the second surface is expressed to be “ΔE*ab”, a relation “0<ΔE*ab≤1.5” is established at all edges positioned inward from each corner by 15 mm in a direction to the center.