PATENT CLAIM ANALYSIS

Application Number: 16072997
Application Type: Utility
Filing Date: 2018-07
Publication Date: 2019-01
Patent Classification: ["174", "258000"]

Abstract:
Provided is a large-sized silicon nitride sintered substrate and a method for producing the same. The silicon nitride sintered substrate has a main surface  101 a  of a shape larger than a square having a side of a length of 120 mm. A ratio dc/de of the density dc of the central area and the density de of the end area of the main surface  101 a  is 0.98 or higher. The void fraction vc of the central area of the main surface  101 a  is 1.80% or lower, and the void fraction ve of the end area is 1.00% or lower. It is preferred that the density dc of the central area is 3.120 g/cm 3  or higher, the density de of the end area is 3.160 g/cm 3  or higher, and a ratio ve/vc of the void fraction vc of the central area and the void fraction ve of the end area is 0.50 or higher.

Claim (Index 13):
A method for producing a silicon nitride sintered substrate, comprising:\n step (a) of mixing Si 3 N 4  powder at 80% by mass or higher and 98.3% by mass or lower, Mg compound powder at 0.7% by mass or higher and 10% by mass or lower as converted into an oxide, and at least one type of rare earth element compound powder at 1% by mass or higher and 10% by mass or lower as converted into an oxide to provide mixed powder; step (b) of putting the mixed powder into a slurry and forming a plurality of greensheets by molding; step (c) of stacking the plurality of greensheets with a boron nitride powder layer being located between each two adjacent greensheets, among the plurality of greensheets, to form a stacked assembly; and step (d) of locating the stacked assembly in a sintering furnace and sintering the stacked assembly; wherein: in the step (c), the boron nitride powder layer has a thickness of 3 \u03bcm or greater and 20 \u03bcm or less; and the step (d) includes:\n step (d1) of removing carbon from the greensheets while maintaining an atmosphere temperature of 900\u00b0 C. or higher and 1300\u00b0 C. or lower in a vacuum atmosphere of 80 Pa of lower; and \n step (d2) of, after the step (d1), sintering the greensheets at an atmosphere temperature of 1600\u00b0 C. or higher and 2000\u00b0 C. or lower in a nitrogen atmosphere.

Metadata:
- Claim Count in Document: 29.0
- Percentile: 95.0
- Lexical Diversity: 2.8
- Patent Class: 174.0
- Transitional Phrase Type: open
- Component Type: 1
- Foreign Priority: True
- Related Applications: ['14241789', '14896775', '15121443', '11630630', '15318005']

Analysis Scores:
- 35 USC 101 Eligibility (BERT): 0.815158283063674
- 35 USC 102 Novelty (BERT): 0.5004541243240752
- Combined Prediction Score: 0.7836878671897142
- Mean Citation Score: 230.126514
- Max Citation Score: 243.75623
- Similarity Product: 177.0003842453748

Labels:
- Claim Label 101: 1
- Claim Label 102: 1
- Claim Label 103: 1
- Claim Label 112: 1
- Combined Label: 1
- Label 101 Adjusted: 1

Dataset: test