CN-122028759-A - Wiring board and method for manufacturing wiring board

Abstract

The invention provides a wiring substrate and a method for manufacturing the same, which has high quality. The wiring board has a first resin insulation layer having a first face, a second face, and a cavity extending from the first face to the second face, a second resin insulation layer having a third face and a fourth face formed on the first resin insulation layer, a member having an electrode facing the fourth face and received in the cavity, and a third resin insulation layer having a fifth face and a sixth face formed on the first resin insulation layer. The cavity has a first side opening and a second side opening. The second resin insulating layer closes the opening on the first surface side, and the third resin insulating layer closes the opening on the second surface side. The second resin insulating layer is closer to a mounting surface for mounting the electronic component than the third resin insulating layer. A portion of the third resin insulation layer fills a gap between an inner wall of the cavity and the part. The cross-sectional shape of the cavity is substantially trapezoidal, and the distance between the opposing legs is substantially reduced from the second face toward the first face.

Inventors

• Makino year show
• Kyoda nobuhisa

Assignees

• 揖斐电株式会社

Dates

Publication Date

20260512

Application Date

20251028

Priority Date

20241106

Claims (18)

1. 1. A wiring substrate is provided with: a first resin insulation layer having a first surface, a second surface opposite to the first surface, and a cavity extending from the first surface to the second surface; A second resin insulation layer having a third surface and a fourth surface opposite to the third surface, the second resin insulation layer being formed on the first resin insulation layer such that the fourth surface faces the first surface; a member having an electrode facing the fourth surface and accommodated in the cavity, and A third resin insulation layer having a fifth face and a sixth face on an opposite side to the fifth face, the third resin insulation layer being formed on the first resin insulation layer with the fifth face facing the second face, Wherein, the The cavity has an opening on a first side of the first face and an opening on a second side of the second face, The second resin insulation layer closes the opening of the first face side, the third resin insulation layer closes the opening of the second face side, The second resin insulation layer is closer to a mounting surface for mounting an electronic component than the third resin insulation layer, A portion of the third resin insulation layer fills a gap between an inner wall of the cavity and the part in the cavity, The cavity has a substantially trapezoidal cross-sectional shape, and of four sides of the trapezoid, sides other than the upper and lower bottoms are opposed legs, and a distance between the opposed legs becomes substantially smaller from the second surface toward the first surface.
2. 2. The wiring substrate according to claim 1, wherein, The first resin insulation layer includes a plurality of resin insulation layers, a resin insulation layer of the plurality of resin insulation layers that is in contact with the second resin insulation layer is an uppermost first resin insulation layer, The resin insulation layer of the plurality of resin insulation layers that is in contact with the third resin insulation layer is the lowermost first resin insulation layer, The surface of the uppermost first resin insulation layer in contact with the second resin insulation layer is the first surface and the surface of the lowermost first resin insulation layer in contact with the third resin insulation layer is the second surface, The cavity penetrates through the plurality of resin insulation layers.
3. 3. The wiring substrate according to claim 1, wherein, The second resin insulation layer doubles as the outermost resin insulation layer.
4. 4. The wiring substrate according to claim 3, wherein, The outermost resin insulation layer is a first solder resist layer.
5. 5. The wiring substrate according to claim 1, wherein, The wiring substrate further includes an outermost resin insulation layer formed on the third face of the second resin insulation layer, The outermost resin insulation layer is in contact with the third face.
6. 6. The wiring substrate according to claim 5, wherein, The outermost resin insulation layer doubles as the first solder mask layer.
7. 7. The wiring substrate according to claim 1, wherein, The wiring board further includes: An adhesive film formed between the second resin insulation layer and the electrode, and And a first via conductor that passes through the second resin insulating layer and the adhesive film at the same time and reaches the electrode.
8. 8. The wiring substrate according to claim 2, wherein, The wiring board further has a second via conductor penetrating through both the third resin insulation layer and the lowermost first resin insulation layer.
9. 9. The wiring substrate according to claim 1, wherein, The wiring substrate further has an adhesive film formed between the second resin insulation layer and the electrode, The member is fixed to the fourth surface of the second resin insulation layer through the adhesive film.
10. 10. The wiring substrate according to claim 2, wherein, The plurality of resin insulation layers does not include a resin insulation layer other than the uppermost first resin insulation layer and the lowermost first resin insulation layer.
11. 11. The wiring substrate according to claim 8, wherein, The second via conductor penetrates only the third resin insulation layer and the lowermost first resin insulation layer.
12. 12. The wiring substrate according to claim 6, wherein, The wiring board further includes: a second solder resist layer formed at a position farthest from the first solder resist layer, and A fourth resin insulation layer which is in contact with the second solder resist layer and is formed at a position on the inner side than the second solder resist layer, The fourth resin insulation layer includes a reinforcing material, The first resin insulation layer, the second resin insulation layer, and the third resin insulation layer do not include a reinforcing material.
13. 13. The wiring substrate according to claim 12, wherein, The first and second solder masks do not contain a reinforcing material, The thickness of the fourth resin insulation layer is greater than the thickness of the first resin insulation layer.
14. 14. The wiring substrate according to claim 4, wherein, The wiring board further includes: a second solder resist layer formed at a position farthest from the first solder resist layer, and A fourth resin insulation layer which is in contact with the second solder resist layer and is formed at a position on the inner side than the second solder resist layer, The fourth resin insulation layer includes a reinforcing material, The first resin insulation layer and the third resin insulation layer do not contain a reinforcing material.
15. 15. The wiring substrate according to claim 1, wherein, An alignment mark is formed on the third face of the second resin insulation layer.
16. 16. A method for manufacturing a wiring board includes the steps of: Forming a metal layer on a support plate; Forming a first alignment mark on the metal layer; Laminating a second resin insulation layer having a third surface and a fourth surface opposite to the third surface on the first alignment mark and the metal layer so that the third surface faces the metal layer; forming a first conductor layer on a fourth surface of the second resin insulation layer; Forming an uppermost first resin insulation layer on the first conductor layer and the second resin insulation layer; Forming a second conductor layer on the uppermost first resin insulation layer; Forming a lowermost first resin insulation layer on the uppermost first resin insulation layer and the second conductor layer; forming a cavity penetrating the uppermost first resin insulation layer and the lowermost first resin insulation layer; receiving a part within the cavity; Forming a third resin insulation layer on the lowermost first resin insulation layer; Forming a third conductor layer on the third resin insulation layer; Removing the support plate and the metal layer, and Forming a first opening penetrating the second resin insulation layer and exposing an electrode of the member, Wherein, the The position of the first opening is associated with the position of the first alignment mark and the position of the component is associated with the position of the first alignment mark.
17. 17. The method for manufacturing a wiring substrate according to claim 16, wherein, The method for manufacturing the wiring substrate further comprises the following steps: forming a second opening penetrating the third resin insulation layer and the lowermost first resin insulation layer to the second conductor layer, and And forming a via conductor connecting the second conductor layer and the third conductor layer in the second opening.
18. 18. The method for manufacturing a wiring substrate according to claim 16, wherein, The method for manufacturing the wiring substrate further includes the step of forming a via conductor filling the first opening.

Description

Wiring board and method for manufacturing wiring board Technical Field The technology disclosed in the present specification relates to a wiring substrate. Background Patent document 1 discloses an electronic component-embedded substrate in which an electronic component is embedded in a cavity formed in a resin insulating layer. Patent document 1 Japanese patent application laid-open No. 2015-106610 [ Problem of patent document 1] As shown in fig. 1 of patent document 1, the electronic component built-in substrate of patent document 1 has a core substrate and an upper laminate layer. The electronic component is accommodated in the cavity in the upper layer. Fig. 5 (B) of patent document 1 shows a cross-sectional shape of the cavity. According to fig. 5 (B) of patent document 1, the wall surface of the cavity of patent document 1 is inclined. The distance between the opposing wall surfaces decreases toward the core substrate. Therefore, as an explanation of the sectional shape of the cavity of patent document 1, an inverted trapezoid is considered to be appropriate. It is considered that when the electronic component built-in substrate of patent document 1 receives thermal shock, the flatness of the upper surface of the upper laminate is lowered. Disclosure of Invention The wiring board of the present invention includes a first resin insulating layer having a first surface, a second surface opposite to the first surface, and a cavity extending from the first surface to the second surface, a second resin insulating layer having a third surface and a fourth surface opposite to the third surface, the second resin insulating layer being formed on the first resin insulating layer such that the fourth surface faces the first surface, a member having an electrode facing the fourth surface and being accommodated in the cavity, and a third resin insulating layer having a fifth surface and a sixth surface opposite to the fifth surface, the third resin insulating layer being formed on the first resin insulating layer such that the fifth surface faces the second surface. The cavity has an opening on a first side of the first face and an opening on a second side of the second face. The second resin insulation layer closes the opening of the first face side, and the third resin insulation layer closes the opening of the second face side. The second resin insulation layer is closer to a mounting surface for mounting an electronic component than the third resin insulation layer. A portion of the third resin insulation layer fills a gap between an inner wall of the cavity and the component within the cavity. The cavity has a substantially trapezoidal cross-sectional shape, and of four sides of the trapezoid, sides other than the upper and lower bottoms are opposed legs, and a distance between the opposed legs becomes substantially smaller from the second surface toward the first surface. A method for manufacturing a wiring board includes the steps of forming a metal layer on a support plate, forming a first alignment mark on the metal layer, laminating a second resin insulation layer having a third face and a fourth face opposite to the third face on the first alignment mark and the metal layer so that the third face faces the metal layer, forming a first conductor layer on the fourth face of the second resin insulation layer, forming an uppermost first resin insulation layer on the first conductor layer and the second resin insulation layer, forming a second conductor layer on the uppermost first resin insulation layer, forming a lowermost first resin insulation layer on the uppermost first resin insulation layer and the second conductor layer, forming a cavity penetrating the uppermost first resin insulation layer and the lowermost first resin insulation layer, receiving a member in the cavity, forming a third resin insulation layer on the lowermost first resin insulation layer, forming a third resin insulation layer on the third resin insulation layer, removing the third resin insulation layer and the support plate, aligning the position of the first resin insulation layer with the first opening, and the position of the first resin insulation layer being exposed. In the wiring board according to the embodiment of the invention, the cross-sectional shape of the cavity is substantially trapezoidal, and the distance between the opposing legs is substantially reduced from the second surface toward the first surface of the first resin insulation layer. The space between the inner wall of the cavity and the component in the cavity is substantially reduced from the second face toward the first face. The size of the outlet of the space on the second face side is larger than the size of the outlet of the space on the first face side. Even if the resin in the space expands due to thermal shock or the like, the expanded resin is difficult to flow out of the space through the outlet on the first surface side. The expanded resin is ha