Printed wiring board

Abstract

The invention provides a printed wiring board with high quality. The printed wiring board has: an uppermost resin insulating layer; an uppermost conductor layer, which is formed on the uppermost resin insulating layer, and which includes a plurality of electrodes on which electronic components are mounted, and a conductor circuit; 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 reaching the electrodes and a second opening reaching the conductor circuit; a weir conductor formed in the second opening; and a metal weir formed on the solder resist layer and the weir conductor. The plurality of electrodes are formed in a mounting region in which the electronic component is mounted, the metal weir substantially surrounds the mounting region, the conductor circuit is a ground circuit or a power supply circuit, and the metal weir is connected to the conductor circuit via the weir conductor.

Description

Technical Field

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

[0002] Patent Document 1 discloses a printed wiring board having a base substrate and dams formed on the base substrate. The dams are formed by applying dam ink on the base substrate by inkjet method and curing the dam ink.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2014-96558

[0004] [Problem of Patent Document 1]

[0005] It is believed that when the wettability of the upper surface of the base substrate is poor, the weir ink is not sufficiently adhered to the upper surface of the base substrate. It is believed that the weir is peeled off from the base substrate. It is believed that the weir is only formed on the upper surface of the base substrate. It is believed that the base substrate is warped due to the curing shrinkage of the weir ink. Summary of the invention

[0006] 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 conductor circuit 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 reaching the electrodes and a second opening for reaching the conductor circuit; a weir conductor formed in the second opening; and a metal weir formed on the solder resist layer and the weir conductor. The plurality of electrodes are formed in a mounting area for mounting the electronic components, the metal weir substantially surrounds the mounting area, the conductor circuit is a ground circuit or a power supply circuit, and the metal weir is connected to the conductor circuit via the weir conductor.

[0007] In the printed wiring board of the embodiment of the present invention, the metal weir is connected to the conductor circuit via the weir conductor. Therefore, the metal weir is difficult to peel off from the upper surface of the solder mask layer. The metal weir does not shrink due to curing. Or, the shrinkage of the metal weir is very small. The metal weir has a higher strength than the resin weir. The printed wiring board is difficult to warp. A high-quality printed wiring board can be obtained. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 It is a plan view schematically showing a printed wiring board according to the embodiment.

[0009] Figure 2 yes Figure 1 Cross-sectional view between II-II.

[0010] Figure 3 yes Figure 1Cross-sectional view between III-III.

[0011] Figure 4 It is a cross-sectional view schematically showing a printed wiring board according to another example of the embodiment.

[0012] Figure 5 It is a cross-sectional view schematically showing a printed wiring board according to a modified example of the embodiment.

[0013] Description of symbols

[0014] 2, 102, 202: printed wiring board; 4: mounting area; 10: top resin insulating layer; 20: top conductor layer; 22: electrode; 24: signal wiring; 30: conductor circuit; 31: first conductor circuit; 32: second conductor circuit; 40: solder resist layer; 50: first opening; 60: second opening; 61: first opening for circuit with same potential; 62: second opening for circuit with same potential; 70: conductor for weir; 71: first conductor for weir; 72: second conductor for weir; 75: via conductor; 80: metal weir; 90: column; 100: metal column. DETAILED DESCRIPTION

[0015] [Implementation Method]

[0016] Figure 1 It is a top view which shows the printed wiring board 2 which concerns on embodiment. Figure 2 yes Figure 1 Cross-sectional view between II-II. Figure 3 yes Figure 1 The cross-sectional view between III-III. Figure 1 to Figure 3 As shown, the printed wiring board 2 has a top resin insulation layer 10, a top conductor layer 20, a solder resist layer 40 having openings 50 and 60, a dam conductor 70 formed in the opening 60, and a metal dam 80. The top resin insulation layer 10 has a first surface 10a and a second surface 10b on the opposite side of the first surface 10a. The top conductor layer 20 is formed on the first surface 10a of the resin insulation layer 10. The solder resist layer 40 is formed on the first surface 10a of the top resin insulation layer 10 and the top conductor layer 20. The printed wiring board 2 may also have a core substrate under the top resin insulation layer 10 and the top conductor layer 20.

[0017] The resin insulating layer 10 is formed of a thermosetting resin. The material of the resin insulating layer 10 may also be a photocurable resin. The resin insulating layer 10 may also contain inorganic particles such as silicon dioxide. The resin insulating layer 10 may also contain a reinforcing material such as glass cloth.

[0018] The top conductor layer 20 has a plurality of electrodes 22 and a conductor circuit 30 for mounting electronic components. The top conductor layer 20 is mainly formed of copper. The top conductor layer 20 is formed by a seed layer 20a and a plating layer 20b on the seed layer 20a. The seed layer 20a is formed by chemical plating or sputtering. The plating layer 20b is formed by electroplating. The top conductor layer 20 may also have a signal wiring 24 in addition to the electrode 22 and the conductor circuit 30. The electrode 22 includes a signal electrode, a power supply electrode, and a grounding electrode. Examples of the conductor circuit 30 are a grounding circuit and a power supply circuit. As the conductor circuit 30, the top conductor layer 20 includes a power supply circuit. Alternatively, as the conductor circuit 30, the top conductor layer 20 includes a grounding circuit. Alternatively, as the conductor circuit 30, the top conductor layer 20 includes a grounding circuit and a power supply circuit. The top conductor layer 20 may also include a conductor circuit 30 having substantially the same potential. The conductor circuit 30 having the same potential is called a circuit with the same potential. When the top conductor layer 20 has a circuit with the same potential, the number of the circuits with the same potential is plural. The first circuit with the same potential is the first conductor circuit 31, the second circuit with the same potential is the second conductor circuit 32, and the third circuit with the same potential is the third conductor circuit 33. The signal wiring 24 is connected to a signal electrode. The power circuit is connected to at least one power electrode. Preferably, one power circuit is connected to three or more power electrodes. The ground circuit is connected to at least one ground electrode. Preferably, one ground circuit is connected to three or more ground electrodes.

[0019] The uppermost conductor layer 20 of the embodiment is Figure 1 Depicted in perspective. Figure 1 Only the signal electrodes are shown, and the power supply electrodes and the ground electrodes are omitted. Figure 1 The electrode 22, the signal wiring 24 and the ground circuit 25 are shown. The ground circuit 25 is an example of the conductor circuit 30. The ground circuit 25 has an opening 251, and the signal wiring 24 is formed in the opening 251. The ground circuit 25 is a continuous pattern (solid pattern). The uppermost conductor layer 20 can have a plurality of ground circuits 25x, 25y, 25z. These are examples of circuits with the same potential. Figure 1 The grounding circuit (first grounding circuit) 25x in FIG. 1 is an example of the first conductor circuit 31, the grounding circuit (second grounding circuit) 25y is an example of the second conductor circuit 32, and the grounding circuit (third grounding circuit) 25z is an example of the third conductor circuit 33. The signal wiring 24 may also be formed between the first conductor circuit 31 and the second conductor circuit 32. In the case where the uppermost conductor layer 20 includes a power supply circuit, Figure 1 The ground circuit in the controller is replaced by the power circuit.

[0020] Electronic components are mounted on the printed wiring board 2 via electrodes 22. A plurality of electrodes 22 are formed in a mounting region 4 for mounting electronic components.

[0021] The solder resist layer 40 is formed on the top resin insulation layer 10 and the top conductor layer 20. The solder resist layer 40 has a plurality of openings 50 and a plurality of openings 60 that penetrate the solder resist layer 40. The opening 50 is a first opening. The opening (first opening) 50 is an opening for exposing the electrode 22, which penetrates the solder resist layer 40 and reaches the electrode 22. The opening 60 is a second opening. The opening (second opening) 60 is an opening for exposing the conductor circuit 30, which penetrates the solder resist layer 40 and reaches the conductor circuit 30. The second opening 60 also serves as an opening for the dam conductor 70. In an embodiment, the second opening 60 reaches the ground circuit 25. In this case, the second opening 60 exposes the ground circuit 25. The number of second openings 60 that reach one conductor circuit 30 is preferably multiple. Each circuit of the same potential is exposed through a plurality of openings 60. In the case where the top conductor layer 20 includes a ground circuit, a plurality of second openings 60 reach one ground circuit. In the case where the top conductor layer 20 includes a power supply circuit, a plurality of second openings 60 reach one power supply circuit. When the uppermost conductor layer 20 includes a plurality of conductor circuits having substantially the same potential (same potential circuits), the second opening 60 is formed for each of the same potential circuits. Examples of the same potential circuits are the first conductor circuit 31 and the second conductor circuit 32. Preferably, the plurality of second openings 60 reach each of the same potential circuits. When the uppermost conductor layer 20 includes a plurality of grounding circuits, an opening 60 is formed for each of the grounding circuits. The number of openings 60 reaching one grounding circuit is preferably plural. When the uppermost conductor layer 20 includes a plurality of power supply circuits, an opening 60 is formed for each of the power supply circuits. The number of openings 60 reaching one power supply circuit is preferably plural. When there are same potential circuits, the second opening 60 includes a first opening 61 for the same potential circuit that reaches the first conductor circuit 31 and a second opening 62 for the same potential circuit that reaches the second conductor circuit 32. Furthermore, the second opening 60 may also include a third opening 63 for the same potential circuit that reaches the third conductor circuit 33. The first opening 61 for the same potential circuit may also be referred to as opening 61. The second opening 62 for the same potential circuit may also be referred to as opening 62. The third opening 63 for the equal potential circuit may also be referred to as the opening 63. The opening 61 exposes the first conductor circuit 31. The opening 62 exposes the second conductor circuit 32. The opening 63 exposes the third conductor circuit 33. The number of openings 61, the number of openings 62, and the number of openings 63 are plural. The number of openings 61 is different from the number of openings 62. The number of openings 61 is different from the number of openings 63. The number of openings 61 and the number of openings 62 may also be the same. The number of openings 61 and the number of openings 63 may also be the same. The size of the first opening 50 is equal to the size of the second opening 60. Alternatively, the size of the second opening 60 is larger than the size of the first opening 50. The shape of the opening 61 is substantially the same as the shape of the opening 62. The shape of the opening 61 is substantially the same as the shape of the opening 63.

[0022] The metal dam 80 prevents the bottom filler from flowing out. The metal dam 80 is formed on the solder resist layer 40 and the dam conductor 70. The metal dam 80 roughly surrounds the mounting area 4. The metal dam 80 is mainly formed of copper. The metal dam 80 is formed by a seed layer 80a and a plating layer 80b on the seed layer 80a. The seed layer 80a forming the metal dam 80 is the same as the seed layer 20a forming the uppermost conductor layer 20. The plating layer 80b forming the metal dam 80 is the same as the plating layer 20b forming the uppermost conductor layer 20.

[0023] The weir conductor 70 is formed in the opening (second opening) 60. The metal weir 80 is connected to the conductor circuit 30 via the weir conductor 70. The weir conductor 70 connecting the metal weir 80 and the conductor circuit 30 is located directly below the metal weir 80. The conductor circuit 30 connected to the metal weir 80 is located directly below the metal weir 80. In the embodiment, the metal weir 80 is connected to the ground circuit 25 via the weir conductor 70. The metal weir 80 may also be connected to the power supply circuit via the weir conductor 70. In the case where the conductor circuit 30 has the first conductor circuit 31 and the second conductor circuit 32, the weir conductor 70 has the first weir conductor 71 formed in the opening 61 and the second weir conductor 72 formed in the opening 62. In the case where the conductor circuit 30 further includes the third conductor circuit 33, the weir conductor 70 has the third weir conductor 73 formed in the opening 63. The metal weir 80 is connected to the first conductor circuit 31 via the first weir conductor 71. The metal weir 80 is connected to the second conductor circuit 32 via the second weir conductor 72. The metal weir 80 is connected to the third conductor circuit 33 via the third weir conductor 73. In this way, one metal weir 80 is connected to a plurality of circuits with the same potential. One metal weir 80 is connected to each circuit with the same potential via a plurality of weir conductors 70. The weir conductor 70 is mainly formed of copper. The weir conductor 70 is formed of a seed layer 80a and a plating layer 80b on the seed layer 80a. The seed layer 80a forming the metal weir 80 and the seed layer 80a forming the weir conductor 70 are common. The plating layer 80b forming the metal weir 80 and the plating layer 80b forming the weir conductor 70 are common. The weir conductor 70 is formed simultaneously with the metal weir 80. The metal weir 80 and the weir conductor 70 are formed integrally. The metal weir 80 and all the weir conductors 70 are formed integrally. In the embodiment, the metal dam 80 is connected to the ground circuit 25 via the dam conductor 70. The metal dam 80 and the conductor circuit 30 are connected by the dam conductor 70. The metal dam 80 is firmly bonded to the ground circuit via the dam conductor 70. The metal dam 80 may also be bonded to the power circuit via the dam conductor 70. In this case, the metal dam 80 is firmly bonded to the power circuit via the dam conductor 70. Since the conductor circuit 30 is covered by the solder resist layer 40, the metal dam 80 connected to the conductor circuit 30 is difficult to fall off from the printed wiring board 2.

[0024] When the metal weir 80 is formed of a plurality of sides, each side is preferably connected to a ground circuit or a power circuit via a weir conductor 70. Each side is preferably connected to a ground circuit or a power circuit via a plurality of weir conductors 70. Figure 1 The dam 80 is formed by four sides 81x, 81y, 81z, and 81w. Each side can also be connected to a ground circuit or a power supply circuit via a dam conductor 70. Each side can also be connected to a circuit with the same potential via a dam conductor 70. Each side can also be connected to different circuits with the same potential via a dam conductor 70. The metal dam 80 is difficult to peel off from the upper surface of the solder resist layer 40.

[0025] In the printed wiring board 2 of the embodiment, the metal dam 80 is connected to the first grounding circuit 25x via the first dam conductor 71. The metal dam 80 is connected to the second grounding circuit 25y via the second dam conductor 72. The metal dam 80 is connected to the third grounding circuit 25z via the third dam conductor 73. One metal dam 80 is connected to at least one conductor circuit 30 via a plurality of dam conductors 70. Therefore, it is difficult for the metal dam 80 to be peeled off from the upper surface of the solder resist layer 40. The metal dam 80 does not shrink due to curing. Alternatively, the shrinkage of the metal dam 80 is smaller than that of the resin. The metal dam 80 has a higher strength than that of the resin dam. The printed wiring board 2 is difficult to warp. A high-quality printed wiring board 2 can be obtained.

[0026] [Method for Manufacturing Printed Wiring Board 2 According to Embodiment]

[0027] A mid-stage substrate having the uppermost resin insulating layer 10 and the uppermost conductor layer 20 is prepared. The uppermost conductor layer 20 has an electrode 22 for mounting electronic components, a signal wiring 24, and a ground circuit 25. The ground circuit 25 includes a first ground circuit 25x, a second ground circuit 25y, and a third ground circuit 25z. The first ground circuit 25x, the second ground circuit 25y, and the third ground circuit 25z are examples of circuits with the same potential. A solder resist layer 40 is formed on the uppermost resin insulating layer 10 and the uppermost conductor layer 20. A plurality of openings 50 and 60 penetrating the solder resist layer 40 are formed. Each opening 50 and the opening 60 is formed by laser. The opening (first opening) 50 exposes the electrode 22. The opening (second opening) 60 exposes the ground circuit 25. The opening 60 has a plurality of openings 61, a plurality of openings 62, and a plurality of openings 63. The opening 61 exposes the first ground circuit 25x. The opening 62 exposes the second ground circuit 25y. The opening 63 exposes the third ground circuit 25z. The size of the opening 50 is equal to the size of the opening 60. Alternatively, the size of the opening 60 is larger than the size of the opening 50. The size of the opening 61 and the size of the opening 62 may also be different. The size of the opening 61 is preferably larger than the size of the opening 62. The size of each opening 50, 60 is measured on the upper surface of the solder resist layer 40 (the surface away from the uppermost resin insulation layer 10). The planar shape of each opening 50, 60 on the upper surface of the solder resist layer 40 is roughly circular. The size of each opening 50, 60 is represented by the diameter on the upper surface of the solder resist layer 40.

[0028] A seed layer 80a is formed on the solder resist layer 40, on the inner wall surfaces of the openings 50 and 60, on the electrode 22 exposed from the opening 50, and on the ground circuit 25 exposed from the opening 60. A plating resist is formed on the seed layer 80a. The plating resist has an opening for forming a metal weir 80 and a weir conductor 70. An electroplating layer 80b is formed on the seed layer 80a exposed from the plating resist. The electroplating layer 80b fills the opening 60. The electroplating layer 80b is formed on the solder resist layer 40. A weir conductor 70 and a metal weir 80 are formed. They are formed simultaneously. The weir conductor 70 is composed of a seed layer 80a in the opening 60 and an electroplating layer 80b on the seed layer 80a. The metal dam 80 is formed by a portion formed by a seed layer 80a on the solder resist layer 40 and a plating layer 80b on the seed layer 80a (a portion on the solder resist layer) and a portion formed by a plating layer 80b on the dam conductor 70 (a portion on the dam conductor). The metal dam 80 is continuous with the dam conductor 70. The metal dam 80 and the dam conductor 70 are formed integrally. The dam conductor 70 joins the grounding circuit 25 to the metal dam 80. A first dam conductor 71 is formed in the opening 61. A second dam conductor 72 is formed in the opening 62. A third dam conductor 73 is formed in the opening 63. The first dam conductor 71 joins the first grounding circuit 25x to the metal dam 80. The second dam conductor 72 joins the second grounding circuit 25y to the metal dam 80. The third dam conductor 73 joins the third grounding circuit 25z to the metal dam 80. The plating resist is removed. The seed layer 80a exposed from the plating layer 80b is removed, thereby obtaining the printed wiring board 2 of the embodiment.

[0029] [Another Example of Implementation]

[0030] Figure 4 A cross-sectional view of a printed wiring board 102 according to another example of the embodiment is shown. Figure 4 Equivalent to Figure 1A cross-sectional view between II-II in FIG. In an example different from the embodiment, the planar shape of the opening 60 is different. The planar shapes of the opening 50 and the opening 60 are observed on the upper surface of the solder resist layer 40. The size of the opening 50 is represented by the area of ​​the planar shape of the opening 50. The size of the opening 60 is represented by the area of ​​the planar shape of the opening 60. The planar shape of the opening 50 of the embodiment and the planar shape of the opening 50 of another example of the embodiment are roughly circular. The planar shape of the opening 60 of the embodiment is roughly circular. In contrast, another example includes an opening 60 having a roughly elliptical planar shape. Alternatively, another example includes an opening 60 having a roughly rectangular planar shape. Another example may also include an opening 60 having a roughly elliptical planar shape and an opening 60 having a roughly rectangular planar shape. Another example may also include an opening 60 having a roughly circular planar shape and an opening 60 having a roughly rectangular planar shape. Another example may also include an opening 60 having a roughly elliptical planar shape and an opening 60 having a roughly circular planar shape. In another example, the size of the opening 60 is larger than the size of the opening 50. The size of the opening 61 is larger than the size of the opening 50. The size of the opening 62 is larger than the size of the opening 50. The planar shape of the opening 61 is substantially elliptical or substantially rectangular. The planar shape of the opening 62 is substantially elliptical or substantially rectangular. The shape of the opening 61 is substantially the same as the shape of the opening 62. In another example of the embodiment, the planar shape of the opening 60 is substantially elliptical.

[0031] Comparing the embodiment with another example, the size of the opening 60 of the other example is larger than that of the embodiment. Therefore, the other example can increase the bonding strength between the metal dam 80 and the ground circuit 25. The metal dam 80 is more difficult to peel off from the upper surface of the solder resist layer 40.

[0032] [Another Example of Method for Manufacturing Printed Wiring Board 102]

[0033] Except for the method for forming the opening 60, the manufacturing method of other examples is the same as the manufacturing method of the embodiment. In another example, the laser is irradiated to the solder resist layer 40 in such a way that the planar shape of the opening 60 has a roughly elliptical or roughly rectangular shape. The planar shape of the opening 60 of another example of the embodiment is roughly elliptical. It is also possible to mix the opening 60 with a roughly elliptical planar shape, the opening 60 with a roughly rectangular planar shape, and the opening 60 with a roughly circular planar shape. It is preferred that the opening 60 with a roughly elliptical planar shape and the opening 60 with a roughly circular planar shape are mixed. Alternatively, it is preferred that the opening 60 with a roughly rectangular planar shape and the opening 60 with a roughly circular planar shape are mixed.

[0034] [Modifications of the Embodiments]

[0035] Figure 5A cross-sectional view of a printed wiring board 202 according to a modified example of the embodiment is shown. Figure 5 Equivalent to Figure 1 The cross-sectional view between III-III in FIG. Figure 5 As shown, the printed wiring board 202 of the modified example has a metal column 100 on the electrode 22. The printed wiring board 202 of the modified example is formed by adding the metal column 100 to the printed wiring board 2 of the embodiment. Alternatively, the printed wiring board 202 of the modified example is formed by adding the metal column 100 to the printed wiring board 102 of another example of the embodiment. The metal column 100 is composed of a via conductor 75 formed in the opening 50 and a column 90 formed on the via conductor 75. The column 90 protrudes from the upper surface of the solder resist layer 40. The column 90 is formed by a portion directly above the via conductor 75 and a portion on the solder resist layer 40 around the opening 50. The via conductor 75 and the column 90 are formed integrally. The via conductor 75 is continuous with the column 90. The via conductor 75 connects the electrode 22 and the column 90. The electronic component is mounted on the printed wiring board 202 via the metal column 100.

[0036] The metal column 100 is mainly formed of copper. The metal column 100 is formed of a seed layer 80a and a plating layer 80b on the seed layer 80a. The seed layer 80a forming the metal dam 80 and the dam conductor 70 is common to the seed layer 80a forming the metal column 100. The plating layer 80b forming the metal dam 80 and the dam conductor 70 is common to the plating layer 80b forming the metal column 100. The metal column 100 and the metal dam 80 are formed at the same time. The column 90 and the metal dam 80 are formed at the same time. The via conductor 75 and the dam conductor 70 are formed at the same time.

[0037] like Figure 5 As shown in FIG. 1 , the height of the upper surface 80T of the metal weir 80 is different from the height of the upper surface 100T of the metal column 100. Figure 5 In the embodiment, the upper surface 100T of the metal column 100 is higher than the upper surface 80T of the metal dam 80. The upper surface 80T of the metal dam 80 may be higher than the upper surface 100T of the metal column 100. The distance between the upper surface 100T of the metal column 100 and the upper surface 80T of the metal dam 80 (the difference in height between the two) is 3 μm or more and 15 μm or less. The difference in height between the two is preferably 5 μm or more and 12 μm or less.

[0038] The printed wiring board 202 of the modification example has the metal pillar 100 in the mounting area 4. The electronic component is mounted on the printed wiring board 202 via the metal pillar 100. Even if the printed wiring board 202 has the metal dam 80, the modification example can easily mount the electronic component on the printed wiring board 202. The metal dam 80 is unlikely to hinder the mounting. The modification example can improve the connection reliability between the electronic component and the printed wiring board 202.

[0039] [Manufacturing Method of Printed Wiring Board 202 According to Modification Example]

[0040] The intermediate substrate having the opening 50 and the opening 60 is formed by the same method as the manufacturing method of the embodiment. Alternatively, the intermediate substrate having the opening 50 and the opening 60 is formed by the same method as the manufacturing method of another example of the embodiment. Therefore, the printed wiring board 202 of the modified example has the same opening 50 and the opening 60 as the embodiment. Alternatively, the printed wiring board 202 of the modified example has the same opening 50 and the opening 60 as the other example of the embodiment. Therefore, the plane shape of the opening 50 of the printed wiring board 202 of the modified example is roughly circular. The plane shape of the opening 60 of the printed wiring board 202 of the modified example is selected from roughly circular, roughly elliptical and roughly rectangular. A seed layer 80a is formed on the solder resist layer 40, on the inner wall surface of the openings 50 and 60, on the electrode 22 exposed from the opening 50, and on the ground circuit 25 exposed from the opening 60. A plating resist is formed on the seed layer 80a. The plating resist has an opening for forming the metal dam 80, the dam conductor 70 and the metal column 100. The plating layer 80b is formed on the seed layer 80a exposed from the plating resist. The plating layer 80b fills the openings 50 and 60. The metal dam 80 having the same elements as those in the embodiment is formed. The metal column 100 composed of the seed layer 80a and the plating layer 80b on the seed layer 80a is formed. The metal column 100 and the metal dam 80 are formed at the same time.

[0041] The plating resist is removed, and the seed layer 80a exposed from the plating layer 80b is removed, thereby obtaining the printed wiring board 202 of the modified example.

[0042] When forming the electroplating layer 80b, the magnitude of the current used to form the metal weir 80 and the magnitude of the current used to form the column 90 are controlled. For example, the magnitude of the current is controlled by using a shielding plate. Modification Example Control the thickness of the electroplating layer 80b forming the metal weir 80 and the thickness of the electroplating layer 80b forming the column 90. The thickness of the electroplating layer 80b forming the metal weir 80 is greater than the thickness of the electroplating layer 80b forming the column 90. Alternatively, the thickness of the electroplating layer 80b forming the metal weir 80 is smaller than the thickness of the electroplating layer 80b forming the column 90. Therefore, the height of the upper surface 90T of the column 90 is different from the height of the upper surface 80T of the metal weir 80. The upper surface 90T of the column 90 is higher than the upper surface 80T of the metal weir 80. In other examples, the upper surface 80T of the metal weir 80 is higher than the upper surface 90T of the column 90. Since the height of the metal column 100 is substantially equal to the height of the metal dam 80, the printed wiring board 202 of the modified example can improve the connection strength between the metal column 100 and the electronic component. Even if the printed wiring board 202 is impacted, the connection reliability between the metal column 100 and the electronic component is likely to be stable for a long time.

Claims

1. A printed wiring board comprising: The topmost resin insulation layer; an uppermost conductive layer formed on the uppermost resin insulating layer and including a plurality of electrodes and conductive circuits for mounting electronic components; a solder resist layer formed on the uppermost resin insulating layer and the uppermost conductor layer, having a plurality of first openings reaching the electrodes and a second opening reaching the conductor circuit; a weir conductor formed in the second opening; as well as a metal dam formed on the solder resist layer and the dam conductor, in, The plurality of electrodes are formed in a mounting region for mounting the electronic component, The metal weir substantially surrounds the installation area, The conductor circuit is a ground circuit or a power circuit, The metal weir is connected to the conductor circuit via the weir conductor.

2. The printed wiring board according to claim 1, wherein The number of the second openings reaching the conductor circuit is plural.

3. The printed wiring board according to claim 1, wherein The conductor circuit includes a first conductor circuit and a second conductor circuit having substantially the same potential as that of the first conductor circuit. The second opening includes a first opening for the equal potential circuit reaching the first conductor circuit and a second opening for the equal potential circuit reaching the second conductor circuit. The weir conductor includes a first weir conductor formed in the first opening for the equal potential circuit and a second weir conductor formed in the second opening for the equal potential circuit. The metal weir is connected to the first conductor circuit via the first weir conductor. The metal weir is connected to the second conductor circuit via the second weir conductor.

4. The printed wiring board according to claim 3, wherein The number of the first openings for the equal potential circuit is multiple, The number of the second openings for the equal potential circuit is plural.

5. The printed wiring board according to claim 3, wherein The uppermost conductor layer further includes a signal wiring formed between the first conductor circuit and the second conductor circuit.

6. The printed wiring board according to claim 1, wherein The size of the first opening is equal to the size of the second opening, or the size of the second opening is larger than the size of the first opening.

7. The printed wiring board according to claim 6, wherein The size of the second opening is larger than the size of the first opening, The planar shape of the second opening is substantially elliptical or substantially rectangular.

8. The printed wiring board according to claim 3, wherein The size of the first opening is equal to the size of the second opening, or the size of the second opening is larger than the size of the first opening.

9. The printed wiring board according to claim 8, wherein The size of the second opening is larger than the size of the first opening, The planar shape of the second opening is substantially elliptical or substantially rectangular.

10. The printed wiring board according to claim 8, wherein The size of the second opening is larger than the size of the first opening, The planar shape of the second opening is substantially elliptical or substantially rectangular. The shape of the first opening for the equal potential circuit is substantially the same as the shape of the second opening for the equal potential circuit.

11. The printed wiring board according to claim 1, wherein The printed wiring board further includes a metal column, the metal column being composed of a via conductor formed in the first opening and a column protruding from the upper surface of the solder resist layer and formed on the via conductor. The electronic component is mounted on the printed wiring board via the metal column.

12. The printed wiring board according to claim 11, wherein The metal weir and the metal column are formed simultaneously.

13. The printed wiring board according to claim 11, wherein The via conductor and the dam conductor are formed simultaneously.

14. The printed wiring board according to claim 11, wherein The height of the upper surface of the metal weir is different from the height of the upper surface of the metal column.

15. The printed wiring board according to claim 4, wherein The number of the first openings for the equal potential circuit is different from the number of the second openings for the equal potential circuit.

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