Printed wiring board

Abstract

To provide a printed wiring board having high shape retainability.SOLUTION: A printed wiring board 10 included in a semiconductor device 200 includes: an outermost resin insulation layer 150U; an outermost conductor layer 158U that is formed on the outermost resin insulation layer 150U; a solder resist layer 70U that is formed on the outermost resin insulation layer 150U and the outermost conductor layer 158U, and that has an opening 71U to expose the outermost conductor layer 158U; a bump 76U formed on the outermost conductor layer 158U that is exposed by the opening 71U; an electronic component 90 that is mounted on the bump 76U; an underfill material 100 that fills a portion between the electronic component 90 and the solder resist layer 70U; and a dam 102 that is formed on the solder resist layer 70U to prevent the flow of the underfill material 100. The dam 102 is formed of a resin containing silica, calcium carbonate and barium sulfate.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] Patent Document 1 discloses a method for manufacturing an electronic component. As shown in Fig. 5 of Patent Document 1, Patent Document 1 forms a dam portion by forcing a dam material into an annular through-hole of a perforated plate. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 11-67799 Summary of the Invention

[0004] <Issues in Patent Document 1> Patent Document 1 states that the dam material can contain ultrafine silica powder or fine rubber particles wrapped in resin in a core-shell type of fine particles. Therefore, it is considered that the shape after printing is difficult to maintain. According to the technology of Patent Document 1, it is considered that it is difficult to improve the productivity of printed wiring boards. [Means for solving the problem]

[0005] The printed wiring board of the present invention comprises an outermost resin insulating layer, an outermost conductor layer formed on the outermost resin insulating layer, a solder resist layer formed on the outermost resin insulating layer and the outermost conductor layer and having an opening for exposing the outermost conductor layer, a bump formed on the outermost conductor layer exposed by the opening, an electronic component mounted on the bump, an underfill material filled between the electronic component and the solder resist layer, and a dam formed on the solder resist layer for preventing the underfill material from flowing. The dam is made of a resin containing silica, calcium carbonate, and barium sulfate.

[0006] In the printed wiring board according to the embodiment of the present invention, the resin forming the dam contains silica, calcium carbonate, and barium sulfate. Therefore, the dam has a height and width close to the target values. The shape retention after printing is high. According to the embodiment, the shape retention after printing can be improved. The productivity of the printed wiring board can be improved. [Brief description of the drawings]

[0007] [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] 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. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] <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.

[0009] 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 layer 150 and connect adjacent conductor layers. Resin insulating layer 150U is the outermost resin insulating layer. Conductor layer 158U is the outermost conductor layer.

[0010] 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 first opening 71U. A conductor layer 158U exposed by the first opening 71U functions as a pad 158p for mounting an electronic component 90. A solder bump 76U for mounting the electronic component 90 is formed on the pad 158p.

[0011] As shown in FIG. 1, the semiconductor device 200 of the embodiment has an underfill material 100 between the electronic component 90 and the solder resist layer 70U. The printed wiring board 10 has a dam 102 on the first solder resist layer 70U to prevent the underfill material 100 from flowing. The dam 102 surrounds the electronic component 90. An example of the planar shape of the dam 102 is a ring. The dam 102 is formed of a resin containing silica, calcium carbonate, and barium sulfate. The resin is a thermosetting epoxy resin. The amount of silica in the resin is 40% by weight or more and 50% by weight or less, the amount of calcium carbonate is 5% by weight or more and 10% by weight or less, and the amount of barium sulfate is 1% by weight or more and 5% by weight or less. In the printed wiring board 10 of the embodiment, the resin forming the dam 102 contains silica, calcium carbonate, and barium sulfate. Therefore, the dam 102 has a height and width close to the target values. The shape retention after printing is high. According to the embodiment, the shape retention after printing is improved. The productivity of the printed wiring board 10 is improved.

[0012] <Method of manufacturing a printed wiring board according to an embodiment> 2 to 5 show a method for manufacturing the printed wiring board 10 of the embodiment.

[0013] The first intermediate substrate 1 shown in Fig. 2 is manufactured. The first intermediate 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 and 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.

[0014] 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 openings 71U that expose the conductor layer 158U. The conductor layer 158U exposed by the openings 71U functions as pads 158p for mounting electronic components 90. Solder bumps 76U are formed on the pads 158p.

[0015] As shown in Fig. 4, a dam 102 is formed on the solder resist layer 70U. The dam 102 is formed by discharging a resin of a dam material. The resin of the dam material contains silica, calcium carbonate, and barium sulfate. The resin of the dam material is discharged using a dispenser (not shown). The resin of the dam material is continuously discharged. After the resin of the dam material is discharged, the dam 102 is hardened. In the printed wiring board 10 of the embodiment, the resin of the dam material is dispensed by a dispenser. Therefore, the printability is high. According to the embodiment, the printability and the shape retention after printing are improved.

[0016] As shown in Fig. 5, electronic components 90 are mounted on solder bumps 76U. As shown in Fig. 1, underfill material 100 is filled between electronic components 90 and solder resist layer 70U. Printed wiring board 10 of the embodiment (see Fig. 1) is obtained. [Explanation of symbols]

[0017] 1: First intermediate board 10: Printed wiring board 30: Core board 70D: Solder resist layer 70U: Solder resist layer 71U: Opening 76U: Solder bump 90: Electronic components 100: Underfill material 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. An outermost resin insulating layer; an outermost conductor layer formed on the outermost resin insulating layer; a solder resist layer formed on the outermost resin insulating layer and the outermost conductor layer, the solder resist layer having an opening for exposing the outermost conductor layer; a bump formed on the outermost conductor layer exposed by the opening; an electronic component mounted on the bump; an underfill material filled between the electronic component and the solder resist layer; a dam formed on the solder resist layer for preventing a flow of the underfill material, The dam is formed from a resin containing silica, calcium carbonate, and barium sulfate.

2. 2. The printed wiring board according to claim 1, wherein the resin is dispensed by a dispenser.

3. 3. The printed wiring board according to claim 2, wherein the resin is discharged continuously.

4. 2. The printed wiring board according to claim 1, wherein the resin is a thermosetting epoxy resin.

5. 5. The printed wiring board of claim 4, wherein the amount of silica in the resin is 40% by weight or more and 50% by weight or less, the amount of calcium carbonate is 5% by weight or more and 10% by weight or less, and the amount of barium sulfate is 1% by weight or more and 5% by weight or less.

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