Silicon nitride substrate, silicon nitride circuit board utilizing the same, and use thereof

Patent 8029903 Issued on October 4, 2011. Estimated Expiration Date:

July 27, 2026. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.

Abstract Claims Description Full Text

Patent References

Method of preparing a self-reinforced silicon nitride ceramic of high fracture toughness Patent #: 5021372
Issued on: 06/04/1991
Inventor: Pyzik, et al.

Inventors

Assignee

Denki Kagaku Kogyo Kabushiki Kaisha

Application

No. 12063478 filed on 07/27/2006

US Classes:

428/446Of silicon containing (not as silicon alloy)

Examiners

Primary: Speer, Timothy
Assistant: Langman, Jonathan

Attorney, Agent or Firm

Oblon, Spivak, McClelland, Maier & Neustadt, L.L.P.

Foreign Patent References

9 157054 JP 06/01/1997
2000 34172 JP 02/01/2000
2002 29849 JP 01/01/2002
2002 29851 JP 01/01/2002

International Classes

B32B 9/00
B32B 9/04
B32B 13/04
B32B 19/00

Abstract

Provided are a silicon nitride substrate and a silicon nitride circuit board with excellent electrical characteristics, and power control parts utilizing them.A silicon nitride substrate comprises a silicon nitride sintered body obtainable by sintering a silicon nitride powder in the presence of a sintering aid comprising MgO, Y2O3 and SiO2 in a proportion of (1) MgO/(MgO+SiO2)=34-59 mol %, and (2) Y2O3/(Y2O3+SiO2)=50-66 mol %, and a silicon nitride circuit board utilizes it.

Other References

R. Sangiorgi, et al., “Wettability of Hot-pressed Silicon Nitride Materials by Liquid Copper”, Materials Science and Engineering A, vol. 103, No. 2, XP 26060539, Sep. 1, 1988, pp. 277-283.
Do-Van Tuyen, et al., “Formation of rod-like Si₃N₄grains in porous SRBSN bodies using 6Y₂O₃-2MgO sintering additives”, Ceramics International, vol. 35, No. 6, XP 26145936, Aug. 1, 2009, pp. 2305-2310.
Marcell Peuckert, et al., “Oxygen distribution in silicon nitride powders”, Journal of Materials Science, vol. 22, XP 2634733, Jan. 1, 1987, pp. 3717-3720.
Peter Greil, “Evaluation of Oxygen Content on Silicon Nitride Powder Surface from the Measurement of the Isoelectric Point”, Journal of the European Ceramic Society, vol. 7, XP 2634732, Jan. 1, 1991, pp. 353-359.
Sea-Hoon Lee, et al., “Effect of spray coated SiO₂layers on the low temperature oxidation of Si₃N₄”, Journal of the European Ceramic Society, vol. 23, No. 8, XP 4409235, Jul. 1, 2003, pp. 1199-1206.
Thanakorn Wasanapiarnpong, et al., “Lower Temperature Pressureless Sintering of Si₃N₄Ceramics using SiO₂-MgO-Y₂O₃Additives without Packing Powder”, Journal of the Ceramic Society of Japan, vol. 114, No. 9, XP 2634731, Sep. 1, 2006, pp. 733-738.
Thanakorn Wasanapiarnpong, et al., “Effect of post-sintering heat-treatment on thermal and mechanical properties of Si₃N₄ceramics sintered with different additives”, Journal of the European Ceramic Society, vol. 26, No. 15, XP 24960362, Jan. 1, 2006, pp. 3467-3475.
Extended European Search Report issued May 11, 2011, in Patent Application No. 06781833.6.
Machine English Translation of JP2002-029851 to Kazuyuki et al., provided by the JPO website, internet retrieval date of Dec. 9, 2010.
Machine English Translation of JP09-157054 to Toichi et al., provided by the JPO website, internet retrieval date of Dec. 9, 2010.