Insulating resin circuit substrate
There is provided an insulating resin circuit substrate including an insulating resin layer and a circuit layer consisting of a plurality of metal pieces disposed to be spaced apart in a circuit pattern shape on one surface of the insulating resin layer, in which in a case where a surface of the insulating resin layer in a gap between the metal pieces is analyzed by SEM-EDX, the area rate of a metal element constituting the metal pieces is less than 2.5%.
1. An insulating resin circuit substrate comprising:
an insulating resin layer;
a circuit layer consisting of a plurality of metal pieces disposed to be spaced apart in a circuit pattern shape on one surface of the insulating resin layer; and
a heat radiation layer is formed on a surface of the insulating resin layer on a side opposite to the circuit layer,
wherein in a case where a surface of the insulating resin layer in a gap between the metal pieces is analyzed by SEM-EDX, an area rate of a metal element constituting the metal pieces is less than 2.5%,
the insulating resin layer prevents the electrical connection between the circuit layer and the heat radiation layer,
in a region of the heat radiation layer, a joining rate of the insulating resin layer to the heat radiation layer is 70% or more, where the region is located on a back surface of the gap between the metal pieces of the circuit layer, and
the heat radiation layer is made of a material having a thermal conductivity higher than a thermal conductivity of the insulating resin layer.
2. The insulating resin circuit substrate according to claim 1 ,
wherein the metal piece has a thickness t of 0.5 mm or more.
3. The insulating resin circuit substrate according to claim 1 ,
wherein a ratio L/t of a closest distance L between the metal pieces to a thickness t of the metal piece disposed in the circuit pattern shape is 2.0 or less.
4. The insulating resin circuit substrate according to claim 1 ,
wherein the insulating resin layer consist of a thermosetting resin having insulating properties and one or more fillers selected from a group consisting of alumina, boron nitride, and aluminum nitride.
5. The insulating resin circuit substrate according to claim 1 ,
wherein the plurality of metal pieces consists of one material selected from a group consisting of an oxygen-free copper, a tough pitch copper, and a copper alloy.
6. The insulating resin circuit substrate according to claim 1 ,
wherein each of the plurality of metal pieces is composed of a punched metal plate.
7. The insulating resin circuit substrate according to claim 1 ,
wherein a closest distance L between the metal pieces disposed in a circuit pattern shape is set such that a ratio L/t to a thickness t of the metal pieces is 2.0 or less.
8. The insulating resin circuit substrate according to claim 7 , wherein the ratio L/t is 1.0 or less.