JP4795575B2 - Laminated wiring board and manufacturing method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a laminated wiring board formed by laminating a conductor layer and an interlayer insulating layer and a method for manufacturing the same. More specifically, the present invention relates to a laminated wiring board having an interlayer conduction structure that conducts three or more conductor layers in one place and a method for manufacturing the same.
[0002]
[Prior art]
Conventionally, in a multilayer wiring board in which conductor layers and interlayer insulating layers are alternately stacked, interlayer conductive structures between multiple layers are arranged everywhere in order to realize various circuits. The following method is generally used as a method for manufacturing a laminated wiring board having a multi-layer conductive structure. First, a plurality of conductor layers and interlayer insulating layers are alternately stacked to form a single laminated wiring board. A through hole is formed in the laminated wiring board with a drill or the like, and plating is performed between the layers. Then, filling the inside of the through hole, lid plating, etc. are performed.
[0003]
[Problems to be solved by the invention]
However, the conventional multilayer wiring board has the following problems. That is, in the interlayer conduction structure of this multilayer wiring board, interlayer conduction is realized by covering the inner wall of the through hole with the metal deposited by plating. This plating conduction has a low connection reliability due to the small connection area. In addition, many steps such as through-hole plating, filling, and lid plating must be performed, which requires a lot of labor for manufacturing.
[0004]
The present invention has been made to solve the problems of the interlayer conductive structure in the conventional multilayer wiring board described above. That is, it is an object of the present invention to provide a multilayer wiring board and a method for manufacturing the same in which the connection area is increased and the number of manufacturing steps is reduced in the interlayer conductive structure.
[0005]
[Means for Solving the Problems]
The multilayer wiring board of the present invention, which has been made for the purpose of solving this problem, is a multilayer wiring board in which conductor layers and interlayer insulating layers are alternately stacked, and is formed on one surface of the first interlayer insulating layer. A conductor pin (A1) that conducts between one conductor layer and the second conductor layer on the other surface, and the second conductor on one surface of the second interlayer insulating layer adjacent to the first interlayer insulating layer The conductor (A) that constitutes the pin (A1) is arranged at the same position in the plate surface of the laminated wiring board with the conductor (B1) that conducts the layer and the third conductor layer on the other surface And the conductor (B) constituting the pin (B1) are in contact and electrically connected, and have different hardness.
[0006]
In the laminated wiring board according to the present invention, the conductor (B) has a higher hardness than the conductor (A), and the conductor (B) is connected at the place where the pin (A1) and the pin (B1) are connected. B) is difficult for the conductor (A).
[0007]
In other words, the interlayer conductive structure of the present invention includes a “pin (A1) ” that penetrates the first interlayer insulating layer and a “pin (B1) ” that penetrates the second interlayer insulating layer adjacent to the first interlayer insulating layer. This is an interlayer connection structure between multiple layers that are connected by arranging them at the same position and conducts three conductor layers. The same position here means the same position in the board surface of the laminated wiring board. Furthermore, the conductor (A) constituting the pin (A1) and the conductor (B) constituting the pin (B1) have different hardness. For this reason, at the place where both pins are connected, the conductor is deformed by the plasticity of the metal, and the conductors are in close contact with each other. Furthermore, since the conductor (B) having high hardness is hard to be inserted into the conductor (A), the connection area of both pins is expanded, and conduction is ensured and reliability is improved.
[0008]
In the method for manufacturing a laminated wiring board according to the present invention, the first conductor layer is provided on one surface and the second conductor layer is provided on the other surface with the first interlayer insulating layer interposed therebetween, and penetrates the first interlayer insulating layer. A substrate (A2) having a pin (A1) with a conductor (A) to be formed, a conductor layer not on one surface of the second interlayer insulating layer, and a third conductor layer on the other surface, the second interlayer insulating layer being A substrate (B2) that penetrates and has a pin (B1) made of a conductor (B) having a hardness different from that of the conductor (A), the other surface of the substrate (A2) and one surface of the substrate (B2) Are combined so that the pin (A1) and the pin (B1) are at the same position in the plate surface of the laminated wiring board , and the combined substrate is pressed and integrated, and the pin (A1) and conductors by electrically connecting in contact the pin (B1) Producing a multilayer wiring board formed by alternately laminating interlayer insulating layer.
[0009]
In this manufacturing method, two substrates on which pins are driven are used as starting materials. The hardness of the conductors that make up the pins is different. First, the substrate is combined with the starting material so that the pins are in the same position. Thereafter, the two substrates are pressed and integrated to form a laminated wiring board. In other words, do not perform lid plating after pressing. This simplifies the manufacturing process.
[0010]
Moreover, in this manufacturing method, the conductor having the higher hardness of the conductor (A) and the conductor (B) protrudes from the surface in contact with the other substrate of the substrate having the conductor before pressing. Good. By pressing this board | substrate (A2) and a board | substrate (B2) , the state which the other conductor protruded into the other conductor after pressing is obtained. This increases the connection area between pins and improves the reliability of conduction.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments embodying the present invention will be described below in detail with reference to the accompanying drawings.
[0012]
A laminated wiring board 100 according to the present embodiment has a cross-sectional structure shown in FIG. The laminated wiring board 100 is a three-layer wiring board having conductor layers 11, 12, and 21 and interlayer insulating layers 10 and 20. Of course, each conductor layer is appropriately patterned. Each interlayer insulating layer has a plate thickness of about 0.05 to 0.15 mm, and the thickness of the copper foil as each conductor layer is about 5 to 20 μm.
[0013]
The laminated wiring board 100 has vias 13 for conducting the conductor layer 11 and the conductor layer 12. In addition, a via 23 for establishing electrical connection between the conductor layer 12 and the conductor layer 21 is provided. The via 13 and the via 23 are overlapped at the same position. Further, the connection portion between the via 13 and the via 23 has a shape in which the material of the via 23 is difficult to be the material of the via 13.
[0014]
The via 13 is obtained by inserting an Ag pin into a hole having a diameter of about 0.06 to 0.30 mm provided in the insulating layer 10. The via 23 is a Cu pin having a diameter of about 0.06 to 0.30 mm that penetrates the insulating layer 20. Therefore, the multilayer wiring board 100 has an interlayer conduction structure in which the conductor layer 11, the conductor layer 12, and the conductor layer 21 are conducted through the via 13 and the via 23.
[0015]
Next, a manufacturing process of the laminated wiring board 100 will be described. The laminated wiring board 100 is manufactured using the resin board 1 with double-sided copper and the resin board 2 with single-sided copper as starting materials. FIG. 2 is a diagram showing a resin plate 1 with double-sided copper. The resin plate 1 with double-sided copper has copper foils (conductor layers) 11 and 12 on both sides. Next, as shown in FIG. 3, the through-hole 14 is opened with the drill with respect to the resin board 1 with a double-sided copper. The through hole 14 is for forming an interlayer conduction structure. The through hole 14 may be formed by laser processing.
[0016]
Next, an Ag pin is inserted into the through hole 14. FIG. 4 is a view showing the resin plate 1 after insertion. The resin plate 1 is electrically connected to the conductor layer 11 and the conductor layer 12 by vias (Ag pins) 13. The length of the via 13 is the same as the thickness of the resin plate 1. Then, the copper foils 11 and 12 of the resin plate 1 in this state are patterned.
[0017]
On the other hand, the resin plate 2 with copper on one side has a copper foil (conductor layer) 21 on one side. A Cu pin 23 is driven into the resin plate 2 with copper on one side so as to penetrate the resin plate 2. FIG. 5 shows the resin plate 2 after driving. Since the resin plate 2 has a via (Cu pin) 23 protruding to the opposite surface of the conductor layer 21, it is possible to establish conduction between the conductor layer 21 and the opposite surface. Then, the copper foil 21 of the resin plate 2 in this state is patterned.
[0018]
Next, the resin plate 1 with a double-sided copper foil in which an Ag pin is inserted and the resin plate 2 with a single-sided copper foil in which a Cu pin is driven are placed so that the via 13 and the via 23 overlap each other vertically. combine. The resin plate 2 with the single-sided copper foil is arranged so that the surface without the copper foil 21 and the resin plate 1 are in contact with each other. Then, the combined resin plate 1 and resin plate 2 are pressed and integrated. At this time, since Cu is harder than Ag, Cu in the via 23 is less likely to be Ag in the via 13, and the laminated wiring board 100 shown in FIG. 1 is manufactured. The laminated wiring board 100 has a structure in which a copper foil 11, an insulating layer 10, a copper foil 12, an insulating layer 20, and a copper foil 21 are laminated in this order. A solder resist may be formed on the surface of the laminated wiring board 100 in this state.
[0019]
Next, a description will be given by paying attention to the connection portion between the via 13 and the via 23 having an interlayer conduction structure made of different metals. FIG. 7 is a diagram showing a part of each of FIGS. 4 and 5 (however, the conductor layer is omitted). First, the pin 13 made of Ag and the pin 23 made of Cu are arranged at the same position. Further, the pin 23 protrudes from the resin plate 2.
[0020]
The resin plate 1 and the resin plate 2 in the above state are pressed to obtain the state shown in FIG. FIG. 8 is a diagram showing a part of FIG. 1 (however, the conductor layer is omitted). In the connection portion between the pin 13 and the pin 23, Cu of the pin 23 is hard to be Ag of the pin 13 during press working. This is a phenomenon due to the plasticity of the metal, because Cu is a metal of a material harder than Ag. Thereby, the connection area of the pin 13 and the pin 23 is expanded, and a sufficient connection area can be secured.
[0021]
In the laminated wiring board 100 of the present embodiment, Cu is used as the hard metal and Ag is used as the soft metal. In addition to this combination, a combination as shown in FIG. 9 is conceivable. In FIG. 9, the metal A has a higher hardness than the metal B. Of course, other metals having different hardnesses can be realized. As the hardness of the metal, a value measured by a test method such as the Rockwell method or the Vickers method may be used.
[0022]
As described above in detail, in the present embodiment, first, the resin plate 1 having an interlayer conduction structure by vias (Ag pins) 13 and the resin plate having an interlayer conduction structure by vias (Cu pins) 23. 2 is combined. At this time, the via 13 and the via 23 are arranged so as to be at the same position. Further, the via 23 protrudes from the resin plate 2. In this state, the resin plate 1 and the resin plate 2 are pressed and integrated. Thereby, the laminated wiring board 100 having an interlayer conduction structure in which the conductor layer 11 and the conductor layer 21 are conducted by the via 13 and the via 23 is manufactured. In the portion where the via 13 and the via 23 of the laminated wiring board 100 are connected, the protruding Cu 23 has a shape in which the Cu of the via 13 is difficult to be Ag. For this reason, the connection area between the via 13 and the via 23 is increased, and the connection reliability is improved.
[0023]
In the present embodiment, no work such as plating is performed after pressing. Therefore, the number of manufacturing processes can be reduced. As a result, a laminated wiring board and a manufacturing method therefor have been realized in which the connection area is enlarged and the number of manufacturing steps is reduced.
[0024]
Note that this embodiment is merely an example, and does not limit the present invention. Therefore, the present invention can naturally be improved and modified in various ways without departing from the gist thereof. For example, Ag and Ag paste correspond to conductors having different hardnesses according to the present invention.
[0025]
Even if the same metal is used, the hardness may differ between the metallurgical manufacturing method and that deposited by plating. For example, Pt is harder when deposited by plating than by metallurgical manufacturing. Therefore, Pt by the metallurgical manufacturing method and Pt deposited by plating correspond to conductors having different hardness as referred to in the present invention.
[0026]
In the present embodiment, two substrates having vias made of materials having different hardnesses are combined. However, any number of substrates may be used as long as the number is two or more. For example, when three substrates are combined, the via materials may be combined in the order of Cu, Ag, and Cu. Of course, it can be realized if the materials of adjacent vias have different hardnesses. Also, the board to be combined can be combined in the order of a board with double-sided copper foil, a board without copper foil, a board with double-sided copper foil, or a board with single-sided copper foil, a board with double-sided copper foil, and a board with single-sided copper foil. It can be realized in various variations.
[0027]
【The invention's effect】
As is apparent from the above description, according to the present invention, there are provided a laminated wiring board and a manufacturing method thereof in which the connection area is increased and the number of manufacturing steps is reduced in the interlayer conductive structure.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a multilayer wiring board according to an embodiment.
2 is a cross-sectional view (Step 1) of a stage in the process of manufacturing the multilayer wiring board of FIG. 1. FIG.
3 is a cross-sectional view (step 2) of a stage in the process of manufacturing the multilayer wiring board of FIG. 1;
4 is a cross-sectional view (step 3) of a stage in the process of manufacturing the multilayer wiring board of FIG. 1;
5 is a cross-sectional view (step 4) of the stage in the process of manufacturing the multilayer wiring board of FIG. 1;
6 is a cross-sectional view (step 5) of a stage in the process of manufacturing the multilayer wiring board of FIG. 1. FIG.
FIG. 7 is a diagram (before pressing) showing interlayer conduction by dissimilar metals.
FIG. 8 is a diagram (after pressing) showing interlayer conduction by dissimilar metals.
FIG. 9 is a diagram showing combinations of metals.
[Explanation of symbols]
10, 20 Interlayer insulation layer 11, 12, 21 Conductor layer (copper foil)
13 Via (Ag pin)
23 Via (Cu pin)
100 laminated wiring board

Claims (6)

In a laminated wiring board in which conductor layers and interlayer insulating layers are alternately laminated,
A conductor pin (A1) that conducts electrical conduction between the first conductor layer on one side of the first interlayer insulating layer and the second conductor layer on the other side, and a second interlayer adjacent to the first interlayer insulating layer Conductor pins (B1) that conduct electricity between the second conductor layer on one side of the insulating layer and the third conductor layer on the other side are arranged at the same position in the plate surface of the laminated wiring board ;
A laminated wiring characterized in that the conductor (A) constituting the pin (A1) and the conductor (B) constituting the pin (B1) are in contact with each other and are electrically connected, and have different hardnesses. Board. In the laminated wiring board according to claim 1,
The conductor (B) has a higher hardness than the conductor (A),
The laminated wiring board, wherein the conductor (B) is not easily inserted into the conductor (A) at a location where the pin (A1) and the pin (B1) are connected. In the laminated wiring board according to claim 1 or 2,
The laminated wiring board, wherein the pin (A1) penetrates the first conductor layer and the pin (B1) penetrates the third conductor layer. In the laminated wiring board according to any one of claims 1 to 3,
The combination of the conductor (A) and the conductor (B) is:
A combination in which the conductor (A) is Ag and the conductor (B) is Cu;
A combination in which the conductor (A) is Cu and the conductor (B) is Ni;
A combination in which the conductor (A) is Ag and the conductor (B) is Ni;
A laminated wiring board, which is any one of the above. In a method for manufacturing a laminated wiring board in which conductor layers and interlayer insulating layers are alternately laminated,
A substrate having a first conductor layer on one surface and a second conductor layer on the other surface across a first interlayer insulating layer, and having a pin (A1) made of a conductor (A) penetrating the first interlayer insulating layer (A2) and a conductor having no conductor layer on one surface of the second interlayer insulating layer and a third conductor layer on the other surface, penetrating the second interlayer insulating layer and having a hardness different from that of the conductor (A). The substrate (B2) having the pin (B1) according to (B) , the other surface of the substrate (A2) and the one surface of the substrate (B2) are opposed to each other, and the pin (A1) and the pin ( B1) and the laminated wiring board so that they are in the same position in the board surface ,
A method of manufacturing a laminated wiring board, wherein the combined substrates are pressed and integrated, and the pins (A1) and the pins (B1) are brought into electrical contact with each other . In the manufacturing method of the laminated wiring board of Claim 5,
The conductor having the higher hardness of the conductor (A) and the conductor (B) protrudes from the surface in contact with the other substrate of the substrate having the conductor before pressing. A manufacturing method of a board.

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