| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a power module substrate which restricts progress of cracks at heat cycle time and also excels in sinterability and bondability. <P>SOLUTION: There is provided a ceramic substrate which is joined with a metal plate constituting a circuit layer to form a power module substrate. It is composed of fibrous Si<SB POS="POST">3</SB>N<SB POS="POST">4</SB>particles and amorphous Si<SB POS="POST">3</SB>N<SB POS="POST">4</SB>particles which both are sintered, characterized in that the fibrous Si<SB POS="POST">3</SB>N<SB POS="POST">4</SB>particles have a short axis diameter of 0.05 μm or more to 3 μm or less, and an aspect ratio of 3 or more to 20 or less, that a portion of the ceramic substrate which the fibrous Si<SB POS="POST">3</SB>N<SB POS="POST">4</SB>particles occupy in one cross section is 5 area% or more to 95 area% or less, and that the average particle size of the amorphous Si<SB POS="POST">3</SB>N<SB POS="POST">4</SB>particles is 1 nm or more to 500 nm or less. <P>COPYRIGHT: (C)2012,JPO&INPIT |
