Circuit board and circuit device
To provide a circuit board that is capable of establishing electrical connection, that is thinner, and that has a higher maintainability. A circuit board includes a substrate including a hole portion that penetrates the substrate in a plate thickness direction, and a connector region including a first conductor layer that closes one side of the hole portion, liquid metal disposed in a recess formed by the hole portion and the first conductor layer, and a sealing layer that is the liquid metal cured on a liquid surface side. The liquid metal may be in contact with a second conductor layer formed in the recess.
1. A circuit board comprising:
a substrate including a hole portion that penetrates the substrate in a thickness direction; and
a connector region including
a first conductor layer that closes one side of the hole portion,
liquid metal disposed in a recess formed by closing one side of the hole portion by the first conductor layer, and
a sealing layer that coats a surface of the liquid metal,
wherein the sealing layer is penetrated by an object to be connected so that the liquid metal in the connector region comes in contact with the object,
wherein the sealing layer is a film obtained by oxidizing the liquid metal at the liquid metal surface in contact with air.
2. The circuit board according to claim 1 , further comprising:
a second conductor layer in the recess, the liquid metal being in contact with the second conductor layer.
3. The circuit board according to claim 2 ,
wherein the second conductor layer is formed of a nickel (Ni) layer.
4. The circuit board according to claim 1 , further comprising:
a second conductor layer provided along the recess, and
a third conductor layer provided on the second conductor layer and in contact with the liquid metal in the hole portion.
5. The circuit board according to claim 4 ,
wherein the third conductor layer is formed of a gold (Au) layer.
6. The circuit board according to claim 1 ,
wherein the liquid metal includes gallium (Ga) and tin (Sn).
7. The circuit board according to claim 1 , wherein the liquid metal includes Ga, indium (In), and Sn.
8. The circuit board according to claim 1 , further comprising:
another substrate on a first conductor layer side of the substrate.
9. The circuit board according to claim 1 , further comprising:
a fourth conductor layer on a side of the first conductor layer opposite to the recess.
10. A circuit device comprising:
the circuit board according to claim 1 ; and
a circuit wiring portion including a conductive and projecting contact portion in contact with the liquid metal.
11. The circuit device according to claim 10 , further comprising:
a spring member that holds the circuit wiring portion to the circuit board.
12. The circuit device according to claim 10 , further comprising:
an adhesive tape that holds the circuit wiring portion to the circuit board.
13. The circuit device according to claim 10 ,
wherein the conductive and projecting contact portion has a conic shape that is tapered towards the circuit board.
14. The circuit device according to claim 10 ,
wherein the conductive and projecting contact portion penetrates the sealing layer and comes in contact with the liquid metal.