Semiconductor-mounting heat dissipation base plate and production method therefor

A method for producing a semiconductor-mounting heat dissipation base plate including:

• an insulating substrate which is formed from a ceramic and to which a metal circuit layer for mounting a semiconductor component thereon and formed from aluminum is fixed by direct bonding through casting;
• and a heat dissipation base formed from aluminum and fixed to the insulating substrate at a side opposite to the metal circuit layer across the insulating substrate by direct bonding through casting, the method comprising
• adhering at least one or more types of a crystal grain size reducing material to a part of a cavity-side surface of a mold during casting of the heat dissipation base and the metal circuit layer, thereby forming a crystal grain diameter regulated region in which crystal grain diameter is regulated, in at least a part of a surface of the heat dissipation base or the metal circuit layer,
• wherein at least one or more types of a crystal grain size reducing material are adhered to a portion of the cavity-side surface of the mold in casting, the portion including at least a surface of a fastening portion provided in the heat dissipation base and opposing a part of the heat dissipation base.

A semiconductor-mounting heat dissipation base plate comprising:

• an insulating substrate which is formed from a ceramic and to which a metal circuit layer for mounting a semiconductor component thereon and formed from aluminum is fixed;
• and
• a heat dissipation base fixed to the insulating substrate at a side opposite to the metal circuit layer across the insulating substrate and formed from aluminum, wherein
• a crystal grain diameter regulated region in which crystal grain diameter is regulated is provided in at least a part of a surface of the metal circuit layer,
• the average crystal grain diameter in the crystal grain diameter regulated region is smaller than an average crystal grain diameter in other regions of the metal circuit layer, and
• the heat dissipation base contacts the insulating substrate.