KR20180054729A - Multi-layer wiring board and manufacturing method thereof - Google Patents

Abstract

A surface layer circuit substrate on which a surface layer circuit and an inner layer circuit are formed, an inner layer circuit substrate on which an inner layer circuit is formed, and a non-penetrating via hole penetrating the surface layer circuit substrate or the inner layer circuit substrate, And an inner layer circuit disposed on the innerlayer circuit board at a position in the thickness direction corresponding to the non-penetrating via, the innerlayer circuit having a through hole penetrating the entire thickness direction of the board.

Description

Multi-layer wiring board and manufacturing method thereof

The present invention relates to a multilayer wiring board, and more particularly, to a multilayer wiring board which has a high degree of freedom of wiring and is highly water-soluble and capable of coping with high frequencies.

2. Description of the Related Art In recent years, as electronic devices have become more sophisticated, it is required to cope with high frequencies and improve the capacity of wiring. With respect to such a demand, it is general that the multilayer wiring board is adapted to adopt a high-frequency-compatible substrate or to have a multi-layered structure.

As a manufacturing method of the multilayer wiring board, there are a method of laminating a plurality of circuit boards having an inner layer circuit, removing unnecessary portions of the outermost layer of the surface copper foil by etching, and a method of forming the necessary portions by copper plating .

As a method for laminating and bonding a plurality of circuit boards, there are a pin lamination method in which a plurality of circuit boards and a prepreg or the like serving as an insulating layer are alternately stacked by using alignment pins and laminated by heating and pressing, There is a build-up method in which a copper foil with an adhesive is stacked on a circuit board to form a laminated body, an unnecessary portion of the copper foil is removed by etching to form a circuit, and this is repeated.

As a method of connecting wirings in the inner layer, there are a method of connecting through holes by drilling through holes, and a method of drilling non-through holes and connecting them as non-through vias (Patent Document 1).

Japanese Patent Publication No. 09-162550

However, in recent years, the speed of electronic devices has been increasing, and electric signals flowing in the wiring board have been increasing in frequency in order to transmit more information in a short time. In designing a wiring board corresponding to a high frequency, it is necessary to consider conductor loss and dielectric loss. To reduce the conductor loss, it is effective to make the conductor of the signal line thick. In order to reduce the dielectric loss, It is effective to lower the relative permittivity and the dielectric tangent of the material to be disposed, but there is a limitation in the conductor width of a signal line that can be coped with in a densified wiring board.

In addition to the demand for higher speed, it is also necessary to cope with an increase in the signal wiring of the wiring board. For increasing the signal wiring, a method of dividing the wiring layers into multiple layers is conceivable. However, there are many cases where it is difficult to form a multi-layered structure due to the limitation of the plate thickness.

Further, in the method of forming the connection in the thickness direction by using the through hole by the through hole, it is necessary to conduct wiring in the other layer than the wiring layer to be connected to the through hole in order to penetrate the through hole. For this reason, there is a problem that the thickness of the wiring is exceeded by multilayering the wiring in order to secure the capacity of the wiring. Further, there is a problem that it is not possible to cope with narrow pitches in which reduction in drill diameter is required, such as a reduction in hole position accuracy and plating performance of through holes, due to the multilayered structure. Further, in a substrate having a large number of through holes, the wiring width and wiring distance are also restricted. In particular, in a high frequency corresponding wiring requiring a high-speed signal, the degree of freedom in designing wiring is reduced, and sufficient electric characteristics may not be obtained.

An object of the present invention is to provide a multilayer wiring board capable of coping with high frequency with high degree of freedom of wiring and high water-solubility.

The present invention relates to the following.

(1) A surface-layer circuit board having a surface-layer circuit and an inner-layer circuit formed thereon, an inner-layer circuit board having an inner-layer circuit formed thereon, and a connecting member connecting the surface-layer circuit and the inner- Wherein the inner layer circuit is disposed on the innerlayer circuit board at a position in the thickness direction corresponding to the non-through vias, the non-through vias having a through-hole penetrating through the entire plate thickness direction.

(2) The multilayer wiring board according to item 1, wherein the inner layer circuit connected to the non-through vias and the inner layer circuit disposed in the inner layer circuit board at the position in the plate thickness direction corresponding to the non-through vias have different wiring widths.

(3) The multilayer wiring board according to item 1 or 2, wherein at least a part of the inner layer circuit is formed of an insulating coating wire.

(4) A method of manufacturing a multilayer wiring board according to any one of items (1) to (3), comprising the steps of: providing a surface layer circuit substrate having a surface layer circuit and an inner layer circuit formed thereon, an inner layer circuit substrate having an inner layer circuit formed thereon, And the unit circuits A and C each having the non-through vias connecting the surface layer circuit and the inner layer circuits or the inner layer circuits and the inner layer circuits disposed on the inner layer circuit board at the position in the plate thickness direction corresponding to the non- (A) forming a unit substrate B having an inner layer circuit formed with an inner layer circuit and having an inner layer circuit disposed on an inner layer circuit board at a position in the thickness direction corresponding to the non-through via, (B) of laminating the unit substrates A, B, and C in the thickness direction in this order.

According to the present invention, it is possible to provide a multi-layered wiring board capable of coping with a high frequency, which has a high degree of freedom of wiring and high water-solubility by having a blind hole and a through hole.

1 is a schematic cross-sectional view of a multilayer wiring board according to an embodiment of the present invention.
2 shows an outline of a manufacturing process of a multilayer wiring board according to an embodiment of the present invention.

(Multilayer wiring board)

One embodiment of the multilayer wiring board of the present invention will be described with reference to Fig. The multilayer wiring board of the present embodiment first has a surface layer circuit board 1a on which a surface layer circuit 12 and an inner layer circuit 2 are formed. The surface layer circuit 12 is a circuit disposed on the outermost layer as a multilayer wiring board, and the surface circuit board 1a is a circuit board disposed on the outermost layer as a multilayer wiring board. The surface circuit board 1a is a circuit board obtained by forming a circuit on both surfaces of an insulating layer (substrate 18) obtained by performing circuit processing on a double-side copper foil of a double-sided copper clad laminate. Therefore, the surface layer circuit 12 is provided on one side and the inner layer circuit 2 is provided on the other side.

The multilayer wiring board of the present embodiment has an inner layer circuit board on which an inner layer circuit is formed. The inner-layer circuit board is a circuit board disposed on the inner layer as a multilayer wiring board. The inner-layer circuit board is a circuit board obtained by performing circuit processing on the both-side copper foil of the double-sided copper-plated laminated board, and circuits are formed on both surfaces of the insulating layer. Therefore, it has an inner layer circuit on both sides.

The multilayer wiring board according to the present embodiment has non-through vias which penetrate the surface layer circuit board or the inner layer circuit board and connect the surface layer circuit and the inner layer circuit or inner layer circuit. That is, as shown in Fig. 1, the multilayer wiring board according to the present embodiment is a non-penetrating via which penetrates only the surface-layer circuit board 1a and connects only the surface-layer circuit 12 and the inner- A surface via hole (SVH) 7, and an inner layer circuit (not shown) which penetrates both the surface layer circuit board 1a and the inner layer circuit board 1b and which is located on the inner layer than the surface layer circuit 12 and the inner layer circuit 2 (Interstitial via holes) 8 connecting the electrodes 3, 4, and 5, respectively. Although not shown in Fig. 1, a blind via hole (BVH) may be provided which penetrates only the inner layer circuit board 1b and connects only the inner layer circuits 2, 3, 4, and 5 to each other. The BVH connecting the inner layer circuits 2, 3, 4 and 5 is also connected to the inner layer circuit of the same inner layer circuit board 1b, the inner layer circuit of the inner layer circuit board 1b, And an inner layer circuit of the substrate 1b is connected.

The non-through vias are non-through interlayer connection holes and electrically connect circuits of other wiring layers. Through holes may be formed by laser processing, drilling, or the like, and then, by plating or the like, conductivity is imparted.

The multilayer wiring board of this embodiment has through-hole penetrating through the entire plate thickness direction. The through-hole is an interlayer connection hole penetrating through the entire plate thickness direction, and electrically connects circuits of other wiring layers. For example, by forming through holes by laser processing, drilling, or the like, and then imparting conductivity by plating or the like.

In the multilayer wiring board of the present embodiment, the inner layer circuit is disposed on the innerlayer circuit board at the position in the thickness direction corresponding to the non-through vias. The position in the plate thickness direction corresponding to the non-through vias refers to the position where the through-hole is formed if a through-hole is formed instead of the non-through vias. In the multilayer wiring board of this embodiment, the inner layer circuit is disposed on the innerlayer circuit board other than the innerlayer circuit board on which the non-through vias are formed so as to include this position.

(Action effect)

According to the multilayer wiring board of the present embodiment, since the innerlayer circuit is also disposed on the innerlayer circuit board in the corresponding thickness direction of the non-through vias, when the interlayer connection is formed by using the through hole, It is possible to arrange the inner layer circuit even in the region of the inner layer circuit substrate which has not been provided, and thus the wiring capacity can be improved. As a result, the degree of freedom of the wiring is increased and the limitations of the wiring width and the wiring distance are also reduced. In particular, in the high frequency corresponding wiring requiring a high speed signal, the degree of freedom in designing the wiring becomes large and sufficient electric characteristics can be obtained. Accordingly, it becomes possible to provide a multilayer wiring board which can increase the degree of freedom of wiring, have high water-solubility, and can cope with high frequencies.

(Modified Example 1)

The inner layer circuit connected to the non-through vias and the inner layer circuit disposed in the inner layer circuit board at the position in the plate thickness direction corresponding to the non-through vias may have different wiring widths. For example, as shown in Fig. 1, the inner layer circuit 3 disposed on the inner layer side of the position corresponding to the SVH 7, rather than the wiring width of the innerlayer circuit 2 connected to the SVH 7, , And a signal line having a wide wiring width. However, if the wiring width is made wider, it can cope with a high frequency. On the other hand, as shown in Fig. 1, for example, the inner layer circuit 4 disposed on the inner layer side of the position corresponding to the SVH 7, rather than the wiring width of the inner layer circuit 2 connected to the SVH 7, Is a signal line having a narrow wiring width. However, if the wiring width is narrowed, it is possible to cope with high density, and the number of wirings can be increased. Thereby, it is possible to provide a multilayer wiring board which is highly water-soluble and can cope with high frequencies.

(Modified example 2)

At least a part of the inner layer circuit may be formed of an insulating coating wire (not shown). Since the inner layer circuit is formed of the insulated coated wire, the multilayer wiring can be achieved by crossing the insulated coated wire in the same wiring layer, thereby further improving the wiring capacity.

(Manufacturing Method of Multilayer Wiring Board)

One embodiment of a method for manufacturing a multilayer wiring board of the present invention will be described with reference to FIG. As shown in FIG. 2A, a method for manufacturing a multilayer wiring board according to the present embodiment is a method for manufacturing a multilayered circuit board in which a surface layer circuit board 1a in which a surface layer circuit 12 and an inner layer circuit 2 are formed, The inner layer circuit 2 and the inner layer circuits 3 and 4 and 5 which penetrate through the surface layer circuit board 1a or the inner layer circuit board 1b and the surface layer circuit 12 and the inner layer circuit 2, And the inner layer circuit 3 is disposed on the inner layer circuit board 1b at the position in the plate thickness direction corresponding to the non-through vias 7, 8 Layer circuit board 1b in which unit circuits A15 and C17 are formed and in which inner layer circuits 4 and 5 are formed and in which the inner layer circuit board 1b at positions in the plate thickness direction corresponding to the non- (A) for forming the unit substrate B16 on which the inner layer circuits 4 and 5 are disposed.

Next, the step (b) of stacking the unit substrates A, B and C produced in the step (a) in this order in the thickness direction is provided.

Then, though not shown, a through hole penetrating through the entire multilayer wiring board after lamination is formed, through-hole plating is performed to form a through-hole, the hole-filling resin is filled in the through-hole, And a step of forming a surface layer circuit by performing circuit processing on the copper plating of the surface layer of the multilayer wiring board including the cover plating.

(Action effect)

According to the method for manufacturing a multilayer wiring board of the present embodiment, unit substrates A, B and C each having a non-through vias or through-hole are unitized into a unit and laminated and integrated. Various non-through vias called BVH can be installed at desired positions. Therefore, in the case of forming the interlayer connection by using the through-hole, the inner layer circuit can be arranged in the region of the inner-layer circuit board where the circuit can not be arranged, and therefore the wiring capacity can be improved. As a result, the degree of freedom of the wiring is increased, the limitation of the wiring width and the wiring distance is also reduced, and the degree of freedom in designing the wiring becomes high and sufficient electric characteristics can be obtained particularly in the high frequency corresponding wiring requiring a high speed signal. Accordingly, it becomes possible to provide a multilayer wiring board which can increase the degree of freedom of wiring, have high water-solubility, and can cope with high frequencies.

Example

1 and 2 show an example in which the multilayer wiring board of the present invention is made into a unit. As shown in Fig. 1, the inner layer circuits 3, 4 and 5 are also arranged at the position in the plate thickness direction corresponding to the SVH 7 to improve the wiring capacity, and at one point with a different wiring width, Width, and the wiring capacity is improved by a narrow wiring width. As shown in FIG. 2A, the SVH 7 and the IVH 8 are drilled with a drill having a diameter of 0.25 mm after the unit substrates A15 and C17 are multilayered, and copper plating 11 (electroless copper Plating, thickness 30 占 퐉), and unnecessary portions were removed by etching. As shown in FIG. 2 (b), the through holes 9 are drilled with a drill having a diameter of 0.25 mm, and then the copper plating 11 (electroless copper plating, After the formation of the copper plating 11 (electroless copper plating, thickness 30 占 퐉), an unnecessary portion is etched away and the hole in the through-hole 9 is filled with a hole- Mu] m, and unnecessary portions were removed by etching to form the multilayer wiring board of Fig.

As described above, by providing the SVH and the inner layer circuit at the position in the plate thickness direction corresponding to the SVH, a multilayer wiring board with high degree of freedom of wiring, high water-solubility, and high frequency response was obtained.

One… Circuit-formed laminated plate or circuit board
1a ... Surface layer circuit board
1b ... Inner layer circuit board
2… (Connected to SVH) inner layer circuit
3 ... (Disposed at a position corresponding to SVH) Inner layer circuit: Signal line
4… (Disposed at a position corresponding to SVH) Inner layer circuit: Signal line with narrow wiring width
5 ... (Placed at a position corresponding to SVH) Inner layer circuit: Ground
6 ... The multilayered adhesive prepreg or prepreg layer
7 ... Non-through vias or SVH: Only through the surface layer, only the surface circuit and the inner layer circuit immediately below
8… Non-through vias or IVH: Connection between surface layer circuit and inner layer circuit other than directly below
9 ... Through hole or through-hole
10 ... Hole filling resin
11 ... Cover plating or copper plating
12 ... Surface layer circuit
15 ... Unit substrate A
16 ... Unit board B
17 ... Unit substrate C
18 ... Substrate or insulating layer

Claims (4)

A surface layer circuit substrate on which a surface layer circuit and an inner layer circuit are formed, an inner layer circuit substrate on which an inner layer circuit is formed, and a non-penetrating via hole penetrating the surface layer circuit substrate or the inner layer circuit substrate, And through-hole penetrating through the entire plate thickness direction,
Layer circuit is disposed on an inner-layer circuit board at a position in the thickness direction corresponding to the non-through vias. The multilayer wiring board according to claim 1, wherein the inner layer circuit connected to the non-through vias and the inner layer circuit disposed in the inner layer circuit board at the position in the plate thickness direction corresponding to the non-through vias have different wiring widths. The multilayer wiring board according to claim 1 or 2, wherein at least a part of the inner layer circuit is formed of an insulating coated wire. A method for manufacturing a multilayer wiring board according to any one of claims 1 to 3,
A surface layer circuit substrate on which a surface layer circuit and an inner layer circuit are formed, an inner layer circuit substrate on which an inner layer circuit is formed, and a non-penetrating via hole penetrating the surface layer circuit substrate or the inner layer circuit substrate, And an inner-layer circuit board having an inner-layer circuit formed thereon, the inner-layer circuit board having an inner-layer circuit formed thereon, the unit substrates A and C having an inner- (A) forming a unit substrate B on which an inner layer circuit is disposed, in an inner layer circuit board at a position in a plate thickness direction corresponding to the via,
(B) of laminating the unit substrates A, B, and C in the thickness direction in this order;
Of the first wiring layer.

Images