Wiring board and method for manufacturing a wiring board

Abstract

To provide a wiring board with which it is possible to suppress a decrease in quality.SOLUTION: A wiring board 10 comprises a wiring layer 20, a solder resist layer 30 that covers the wiring layer 20, and an opening 31 that penetrates the solder resist layer 30 in the thickness direction, causing the top face of the wiring layer 20 to be exposed in part. The wiring board 10 further includes a plating layer 41 that is formed on the wiring layer 20 exposed from the opening 31 and formed inside of the opening 31, a space S1 that is provided between a side surface 53 of the plating layer 41 and an inner wall surface 32 of the opening 31, and a plating layer 42 that covers the entire surface of the plating layer 41 that is exposed from the solder resist layer 30. The plating layer 41 is constructed from nickel or nickel alloy. The plating layer 42 is constructed from a metal that is less susceptible to oxidation than the metal constituting the plating layer 41. The plating layer 42 covers the entire side surface of the plating layer 41 that is exposed from the solder resist layer 30 in the space S1.SELECTED DRAWING: Figure 2

Claims

1. Wiring layer and A protective insulating layer covering the aforementioned wiring layer, An opening that penetrates the protective insulating layer in the thickness direction and exposes a part of the upper surface of the wiring layer, A first plating layer is formed on the wiring layer exposed from the opening, and is formed inside the opening. A gap is provided between the side surface of the first plating layer and the inner wall surface of the opening, It has a second plating layer that covers the entire surface of the first plating layer exposed from the protective insulating layer, The first plating layer is made of nickel or a nickel alloy. The second plating layer is made of a metal that is less susceptible to oxidation than the metal constituting the first plating layer. The second plating layer is formed in the gap such that it covers the entire side surface of the first plating layer that is exposed from the protective insulating layer. A recess communicating with the opening is formed on the upper surface of the wiring layer. The recess is formed so as to expose a portion of the lower surface of the protective insulating layer. The first plating layer is formed to fill the recesses on the wiring substrate.

2. The present invention further comprises a third plating layer that covers the entire surface of the second plating layer exposed from the protective insulating layer, The second plating layer is made of palladium or a palladium alloy. The wiring substrate according to claim 1, wherein the third plating layer is made of gold or a gold alloy.

3. The first plating layer has a filling portion that fills the recess and a columnar portion that protrudes upward from the upper surface of the filling portion. The wiring board according to claim 1, wherein the second plating layer is formed to cover the entire upper surface of the columnar portion, the entire side surface of the columnar portion, and the entire upper surface of the filling portion exposed from the columnar portion.

4. The first plating layer has a projection provided on the outer edge of the upper surface of the first plating layer, The wiring board according to claim 1, wherein the protruding portion is formed to protrude above the other portion of the upper surface of the first plating layer.

5. The wiring board according to claim 4, wherein the protrusion is formed such that the amount of protrusion increases from the planar center side of the first plating layer toward the outer edge of the upper surface of the first plating layer.

6. A step of forming a protective insulating layer that covers the wiring layer and has an opening that exposes a part of the upper surface of the wiring layer, A step of forming a first plating layer made of nickel or a nickel alloy on the wiring layer exposed from the opening by an electroless plating method, A step of etching a portion of the first plating layer to form a gap between the side surface of the first plating layer and the inner wall surface of the opening, The process includes a step of forming a second plating layer that covers the entire surface of the first plating layer exposed from the protective insulating layer by an electroless plating method, Prior to the step of forming the first plating layer, the process further includes the step of forming a recess on the upper surface of the wiring layer exposed from the opening, The recess is formed so as to expose a portion of the lower surface of the protective insulating layer, The first plating layer is formed to fill the recess and protrude into the interior of the opening, The second plating layer is made of a metal that is less susceptible to oxidation than the metal constituting the first plating layer. A method for manufacturing a wiring board, wherein the second plating layer is formed in the gap such that it covers the entire side surface of the first plating layer that is exposed from the protective insulating layer.

7. The process further includes a step of forming a third plating layer that covers the entire surface of the second plating layer exposed from the protective insulating layer by an electroless plating method, The second plating layer is made of palladium or a palladium alloy. The third plating layer is made of gold or a gold alloy. The method for manufacturing a wiring board according to claim 6, wherein the third plating layer is formed in the gap to cover the entire side surface of the second plating layer that is exposed from the protective insulating layer.

Images