Printed wiring board and method for manufacturing printed wiring board

Abstract

To provide a printed wiring board in which the width and height of a dam can be controlled as desired.SOLUTION: A printed wiring board includes a top resin insulating layer, a top conductor layer formed on the top resin insulating layer and including a plurality of electrodes and a frame-shaped base for mounting electronic components, a solder resist layer formed on the top resin insulating layer and the top conductor layer and having a plurality of first openings for exposing the electrodes and a second opening for exposing the frame-shaped base, bumps formed on the electrodes exposed by the first openings, the electronic components mounted on the bumps, an underfill material filled between the electronic components and the solder resist layer, and a dam for preventing the underfill material from flowing. The dam is formed by connecting a plurality of solder balls, and the dam is formed on the frame-shaped base.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The technology disclosed in this specification relates to a printed wiring board and a method for manufacturing a printed wiring board. [Background technology]

[0002] Patent Document 1 discloses a printed circuit board having a base substrate and a dam formed on the upper portion of the base substrate. The dam is formed by applying a dam ink by an inkjet method. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2014-96558 A Summary of the Invention

[0004] [Problem of Patent Document 1] In the technology of Patent Document 1, it is believed that the dam ink spreads on the base substrate due to the impact when applied, making it difficult to control the width of the dam. [Means for solving the problem]

[0005] The printed wiring board of the present invention comprises a top resin insulating layer, a top conductor layer formed on the top resin insulating layer and including a plurality of electrodes and a frame-shaped base for mounting electronic components, a solder resist layer formed on the top resin insulating layer and the top conductor layer and having a plurality of first openings for exposing the electrodes and a second opening for exposing the frame-shaped base, bumps formed on the electrodes exposed by the first openings, the electronic components mounted on the bumps, an underfill material filled between the electronic components and the solder resist layer, and a dam for preventing the underfill material from flowing. The dam is formed by connecting a plurality of solder balls, and the dam is formed on the frame-shaped base.

[0006] In the printed wiring board according to the embodiment of the present invention, the solder resist layer has a second opening. The second opening exposes a frame-shaped base. The dam is formed on the frame-shaped base. The dam is formed by connecting a plurality of solder balls. Therefore, the width of the dam can be controlled by the width of the second opening. The height of the dam can be controlled by the diameter of the solder balls. According to the embodiment, a dam having a desired width and height can be formed.

[0007] The method for manufacturing a printed wiring board of the present invention includes forming a top resin insulating layer, forming a top conductor layer on the top resin insulating layer, the top conductor layer including a plurality of electrodes and a frame-shaped base for mounting electronic components, forming a solder resist layer on the top resin insulating layer and the top conductor layer, the solder resist layer having a plurality of first openings for exposing the electrodes and a second opening for exposing the frame-shaped base, forming bumps on the electrodes exposed by the first openings, forming a plurality of solder balls on the frame-shaped base exposed by the second openings, forming a dam for preventing the flow of underfill material by connecting the plurality of solder balls on the frame-shaped base, mounting the electronic components on the bumps after forming the dam, and filling the gap between the electronic components and the solder resist layer with the underfill material. The dam surrounds the electronic components.

[0008] In the manufacturing method according to the embodiment of the present invention, a solder resist layer having a second opening is formed. The second opening exposes a frame-shaped base. A plurality of solder balls are formed on the frame-shaped base. A dam is formed by connecting the plurality of solder balls on the frame-shaped base. Therefore, the width of the dam can be controlled by the width of the second opening. The height of the dam can be controlled by the diameter of the solder balls. In the printed wiring board formed by the manufacturing method of the embodiment, a dam having a desired width and height can be formed. [Brief description of the drawings]

[0009] [Figure 1]FIG. 1 is a cross-sectional view illustrating a printed wiring board according to an embodiment. [Diagram 2] 1A to 1C are cross-sectional views each showing a schematic diagram of a method for manufacturing a printed wiring board according to an embodiment. [Diagram 3] 1A to 1C are cross-sectional views each showing a schematic diagram of a method for manufacturing a printed wiring board according to an embodiment. [Figure 4] 1A to 1C are cross-sectional views each showing a schematic diagram of a method for manufacturing a printed wiring board according to an embodiment. [Diagram 5] FIG. 4 is a plan view showing a schematic diagram of a substrate in progress according to the embodiment. [Figure 6] 1A to 1C are cross-sectional views each showing a schematic diagram of a method for manufacturing a printed wiring board according to an embodiment. [Figure 7] FIG. 4 is a plan view showing a schematic diagram of a substrate in progress according to the embodiment. [Figure 8] 1A to 1C are cross-sectional views each showing a schematic diagram of a method for manufacturing a printed wiring board according to an embodiment. [Figure 9] FIG. 4 is a plan view showing a schematic diagram of a substrate in progress according to the embodiment. [Figure 10] 1A to 1C are cross-sectional views each showing a schematic diagram of a method for manufacturing a printed wiring board according to an embodiment. [Figure 11] FIG. 13 is a plan view showing a schematic diagram of an intermediate substrate having a second opening in the shape of a square frame according to an embodiment. [Figure 12] FIG. 13 is a plan view showing a schematic diagram of an intermediate substrate having a second opening in the shape of a square frame according to an embodiment. [Figure 13] FIG. 13 is a plan view showing a schematic diagram of an intermediate substrate having a second opening in the shape of a square frame according to an embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] <Printed Wiring Board of the Embodiment> Fig. 3 shows a cross section of intermediate substrate 2. Fig. 1 is a cross section of semiconductor device 200 of an embodiment. Semiconductor device 200 is formed of printed wiring board 10 of the embodiment and electronic component 90 mounted on printed wiring board 10.

[0011] 1, printed wiring board 10 has core substrate 30 and buildup layers 80A, 80B formed on the front and back sides of core substrate 30. Buildup layers 80A, 80B are formed of resin insulating layers 150U, 150L, ​​conductor layers 158U, 158L, and via conductors 160U, 160D that penetrate resin insulating layers 150U, 150L and connect adjacent conductor layers. Resin insulating layer 150U is the uppermost resin insulating layer. Conductor layer 158U is the uppermost conductor layer.

[0012] The printed wiring board 10 has solder resist layers 70U and 70D on the build-up layers 80A and 80B. The solder resist layer 70U has a plurality of first openings 71U and a second opening 96. The conductor layer 158U includes a frame-shaped base 95 on the resin insulating layer 150U. The conductor layer 158U exposed by each of the first openings 71U functions as a plurality of pads (electrodes) 158p for mounting the electronic components 90. A bump 76U for mounting the electronic components 90 is formed on each of the pads 158p. The bump 76U is formed of solder. Alternatively, the bump 76U is formed by plating. The plurality of pads 158p are arranged within the mounting area. The second opening 96 is formed so that the mounting area is surrounded by connecting a plurality of circles. The second opening 96 reaches the frame-shaped base 95. The planar shape of the second opening 96 is frame-shaped. The frame-shaped base 95 is exposed by the second opening 96.

[0013] 1, a semiconductor device 200 according to an embodiment has an underfill material 100 filled between an electronic component 90 and a solder resist layer 70U. A printed wiring board 10 has a dam 102 for preventing the underfill material 100 from flowing on a frame-shaped base 95. The dam 102 surrounds the electronic component 90. The dam 102 is formed by connecting a plurality of solder balls. An example of the planar shape of the dam 102 is a ring.

[0014] <Method of manufacturing a printed wiring board according to an embodiment> 2 to 10 show a method for manufacturing the printed wiring board 10 of the embodiment.

[0015] The in-progress substrate 1 shown in Fig. 2 is manufactured. The in-progress substrate 1 has a core substrate 30, an upper buildup layer 80A, and a lower buildup layer 80B. The core substrate 30 and the buildup layers 80A, 80B are manufactured by a well-known method. The upper buildup layer 80A has a resin insulating layer 150U and a conductor layer 158U on the resin insulating layer 150U. The conductor layer 158U includes a plurality of pads 158p and a frame-shaped base 95.

[0016] 3, a solder resist layer 70U is formed on the resin insulating layer 150U and the conductor layer 158U. The solder resist layer 70U has a plurality of first openings 71U. The conductor layer 158U exposed by each of the first openings 71U functions as a pad 158p on which an electronic component 90 is mounted. A bump 76U is formed on the pad 158p.

[0017] As shown in Fig. 4, a second opening 96 exposing a frame-shaped base 95 is formed in the solder resist layer 70U. As shown in Fig. 5, the second opening 96 is formed so as to surround the mounting area by connecting a plurality of circles. The second opening 96 is formed by a laser or a photography technique.

[0018] 6, a plurality of solder balls 101 are formed on the frame-shaped base 95 exposed by the second opening 96. As shown in FIG 7, each solder ball 101 is formed on the frame-shaped base 95 in each circle of the second opening 96.

[0019] As shown in Fig. 8, the multiple solder balls 101 are subjected to a reflow process. As shown in Fig. 9, the multiple solder balls 101 on the frame-shaped base 95 are connected together. A dam 102 is formed by the multiple connected solder balls 101. The dam 102 protrudes from the solder resist layer 70U.

[0020] In the embodiment, the dam 102 is formed on a frame-shaped base 95 in the second opening 96. Therefore, the width of the dam 102 can be controlled by the width of the second opening 96. The dam 102 is formed by connecting a plurality of solder balls 101. Therefore, the height of the dam 102 can be controlled by the diameter of the solder balls 101. According to the embodiment, the dam 102 having the desired width and height is formed.

[0021] As shown in Fig. 10, an electronic component 90 is mounted on the bumps 76U. As shown in Fig. 1, an underfill material 100 is filled between the electronic component 90 and the solder resist layer 70U. A semiconductor device 200 (see Fig. 1) of the embodiment is obtained.

[0022] As shown in FIG. 11, the intermediate substrate of the printed wiring board 10 of another embodiment has a second opening 96 having a different shape from that of FIG. 5. The second opening 96 is a square frame shape that is not a shape connecting multiple circles. The second opening 96 is formed using a laser or by photography. As shown in FIG. 12, a plurality of solder balls 101 are formed on the frame-shaped base 95 exposed by the second opening 96. As shown in FIG. 13, the plurality of solder balls 101 are reflowed. The plurality of solder balls 101 on the frame-shaped base 95 are connected. A dam 102 is formed by the plurality of connected solder balls 101. [Explanation of symbols]

[0023] 1: Intermediate board 2: Intermediate board 10: Printed wiring board 30: Core board 70D: Solder resist layer 70U: Solder resist layer 71U: 1st opening 76U: Bump 80A: Build-up layer 80B: Build-up layer 90: Electronic components 95: Frame-shaped base 96: Second opening 100: Underfill material 101: Solder ball 102: Dam 150U: Resin insulation layer 158L: Conductive layer 158U: Conductor layer 158p: Pad 160D: Via conductor 160U: Via conductor 200: Semiconductor device

Claims

1. A top resin insulating layer; an uppermost conductor layer formed on the uppermost resin insulating layer and including a plurality of electrodes and a frame-shaped base for mounting electronic components; a solder resist layer formed on the uppermost resin insulating layer and the uppermost conductor layer, the solder resist layer having a plurality of first openings for exposing the electrodes and a second opening for exposing the frame-shaped base; a bump formed on the electrode exposed by the first opening; The electronic component mounted on the bump; an underfill material filled between the electronic component and the solder resist layer; and a dam for preventing the flow of the underfill material, The dam is formed by connecting a plurality of solder balls, and the dam is formed on the frame-shaped base.

2. 2. The printed wiring board according to claim 1, wherein the plurality of electrodes are disposed within a mounting area, and the second opening is formed so that the mounting area is surrounded by connecting a plurality of circles.

3. 2. The printed wiring board according to claim 1, wherein the second opening has a frame-like planar shape.

4. 2. The printed wiring board of claim 1, wherein the second opening is formed by a laser or a photographic technique.

5. forming a top resin insulating layer; forming a top conductor layer including a plurality of electrodes and a frame-shaped base for mounting electronic components on the top resin insulating layer; forming a solder resist layer on the uppermost resin insulating layer and the uppermost conductor layer, the solder resist layer having a plurality of first openings for exposing the electrodes and a second opening for exposing the frame-shaped base; forming a bump on the electrode exposed by the first opening; forming a plurality of solder balls on the frame-shaped base exposed by the second opening; forming a dam for preventing a flow of an underfill material by connecting the plurality of solder balls on the frame-shaped base; mounting the electronic component on the bump after forming the dam; and filling the gap between the electronic component and the solder resist layer with the underfill material, The dam surrounds the electronic component.

6. 6. The method for manufacturing a printed wiring board according to claim 5, wherein the dam is formed by subjecting the plurality of solder balls to a reflow treatment.

7. 6. The method for manufacturing a printed wiring board according to claim 5, wherein the plurality of electrodes are disposed within a mounting area, and the second opening is formed so that the mounting area is surrounded by connecting a plurality of circles.

8. 6. The method for manufacturing a printed wiring board according to claim 5, wherein the second opening has a frame-like planar shape.

9. 6. The method for manufacturing a printed wiring board according to claim 5, wherein the second opening is formed by a laser or a photographic technique.

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