JP6768186B2 - Multi-wire wiring board - Google Patents

Description

The present invention relates to a multi-wire wiring board, and more particularly to a multi-wire wiring board in consideration of a plurality of types of impedance control.

There is an increasing demand for improvement of high-frequency signal transmission characteristics (high-frequency characteristics) in order to respond to higher functionality and higher speed of electronic devices.

As a wiring board that meets the demand for such high frequency characteristics, a structure in which a power supply layer and / or a ground layer formed by processing a metal foil is arranged above and below an insulating coated wire which is a signal line layer via an insulating layer. The conductor of the power supply layer or the ground layer, which is the wiring board of the above and has two or more layers of the insulating coated wire which is the signal line layer, and is arranged immediately above or below the intersection of the signal lines, is partially provided. A multi-wire wiring board that has been removed is known (Patent Document 1).

Further, by laying the insulation-coated wire that is not used as a circuit while avoiding the place where the insulation-coated wire used as a circuit is to be laid, the layer between the insulation-coated wires or the layer between the inner layer pattern and the insulation-coated wire is laid. A method for manufacturing a multi-wire wiring board that realizes a uniform thickness (insulation distance) and enables impedance control is disclosed (Patent Document 2).

Japanese Unexamined Patent Publication No. 2006-294683 JP-A-2002-043749

However, although the multi-wire wiring boards of Patent Documents 1 and 2 are excellent in impedance control and high frequency characteristics, they perform one type of impedance control for one wire layer, and a plurality of types of impedance control are required. In this case, it is necessary to use a plurality of wire layers or to stack a plurality of inner layers, which is also a factor that causes an increase in cost due to a high number of layers.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a multi-wire wiring board capable of controlling a plurality of types of impedances without increasing the number of wire layers and inner layers.

The present invention relates to the following.
1. 1. An inner layer substrate having an inner layer pattern formed by circuit processing a metal foil bonded on an insulating substrate, a wire layer laminated on the inner layer substrate and having an insulating layer and an adhesive layer, and a wire layer of the cloth layer. It has a wire pattern formed by laying an insulating coating wire on an adhesive layer and a conductor pattern laminated on the cloth pattern via an insulating layer, and has the same adhesive layer of the cloth layer. Shielded by a wire pattern formed by laying other insulating coated wires arranged so as to intersect multiple times with continuous insulating coated wires on the upper side of the wire pattern formed by laying the insulating coated wires. A multi-wire wiring board in which a wire pattern that has been made and a wire pattern that is not shielded by other wire patterns are mixed and arranged .
2 . Oite to claim 1, the wiring pattern formed by laid another insulating coated wire, meander, zigzag, or combinations or combination with so as arranged as a multi-wire line of each other these Board.

An object of the present invention is to provide a multi-wire wiring board capable of controlling a plurality of types of impedances without increasing the number of wire layers and inner layers.

It is a schematic plan view which showed the wiring pattern of the multi-wire wiring board which shows one Embodiment of this invention. It is the schematic sectional drawing of the multi-wire wiring board which shows one Embodiment of this invention.

A multi-wire wiring board according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2. Multiwire wiring board of the present embodiment, the inner layer substrate 3 a having an inner layer pattern 2a having a metal foil bonded on the insulating substrate 1 a formed by circuit processing is laminated on the inner layer substrate 3 on a, A wire layer 6 having an insulating layer 4 and an adhesive layer 5, a wire pattern 11 c formed by laying an insulating coating wire 7 on the adhesive layer 5 of the wire layer 6, and a wire pattern 11 c. It has a conductor pattern 2b laminated on top of it via an insulating layer 10, and the wire layer 6 has a wire pattern 11a shielded by another wire pattern 11b on the same adhesive layer 5. , A single wire pattern 11c that is not shielded by other cloth patterns is mixed and arranged.

The inner layer substrate having an inner layer pattern has an inner layer pattern that serves as a ground layer for controlling the characteristic impedance. It can be formed by using an insulating substrate with a metal foil, and for example, a glass epoxy substrate with a copper foil, a glass polyimide substrate, or the like used for manufacturing a general printed wiring board can be used. The circuit processing of the metal foil for forming the inner layer pattern can be performed by a method used in the manufacture of a general printed wiring board, such as a so-called subtract method, a semi-additive method, or an additive method.

As the wire layer, one having an adhesive layer for fixing the insulating coated wire formed on the insulating layer can be used. As the insulating layer, a prepreg used in a general printed wiring board can be used, and the prepreg can be formed by heating and pressurizing on the inner layer substrate. As the adhesive layer, those generally used in multi-wire wiring boards can be used. For example, a varnish in which a phenoxy resin or an epoxy resin is combined with a cationic photopolymerization initiator and a tin compound can be mentioned. Examples of the method for forming the adhesive layer include a method of directly applying and drying on the insulating layer by spray coating, roll coating, screen printing or the like. As another method for forming the adhesive layer, a carrier film such as polypropylene or polyethylene terephthalate is once roll-coated, coated and dried to form a dry film, and then hot-roll-laminated or laminated press is applied on the insulating layer 4. A method of forming the film can be mentioned, and in this case, the thickness of the adhesive layer can be made uniform, which is preferable in order to improve the characteristic impedance. An example of such a dry film is AS-U01 (manufactured by Hitachi Chemical Co., Ltd., trade name). As a result, a wire substrate having a cloth layer having an insulating layer and an adhesive layer formed on the inner layer is formed.

The insulating coated wire refers to a wire obtained by coating a wire serving as a signal line with an insulating resin. The insulating coated wire includes a wire serving as a signal line and a wire coating layer serving as an insulating layer arranged around the wire. The wire is an electric wire serving as a signal line, and copper is generally used as the wire. Further, the wire diameter means the diameter of only the electric wire excluding the insulating resin covering the wire. The wire coating layer is formed by using an insulating resin. As such an insulating resin, any one of a fluorine-based resin, a polyamide-imide-based resin, and a low-dielectric polyimide resin, or a combination of two or more of these is used.

The wire pattern can be formed by melt-bonding the insulating coated wire to the adhesive layer on the insulating layer while applying ultrasonic waves and a load using a dedicated wire machine.

A conductor pattern laminated via an insulating layer is arranged on the wire pattern. This conductor pattern serves as a ground layer for controlling the characteristic impedance.

The multi-wire wiring board of the present embodiment has a wire pattern in which the wire layers are shielded by another wire pattern on the same adhesive layer, and a single wire pattern that is not shielded by another wire pattern. Are mixed and arranged to form. A line pattern shielded by another line pattern (hereinafter, may be referred to as a shielded line pattern) refers to a line pattern covered by another line pattern, and is another line pattern. Refers to a wire pattern for shielding, which acts as a shield for the covered cloth pattern. In addition, a single line pattern that is not shielded by other line patterns (hereinafter referred to as a single line pattern) is literally a single line pattern, and may be covered by another line pattern. Not. In the present embodiment, the shielded line pattern and the single line pattern are arranged in the same adhesive layer in a mixed manner by being lined.

(Action effect)
According to the multi-wire wiring board of the present embodiment, as shown in FIG. 2, the wire pattern 11b for shielding and the inner layer pattern as the ground layer of the inner layer substrate 3a are sandwiched between the shielded wire pattern 11a. 2a is arranged, and an insulation distance 14 is formed between the wire pattern 11b for shielding and the inner layer pattern 2a. On the other hand, the conductor pattern 2b as the ground layer of the inner layer substrate 3b and the inner layer pattern 2a as the ground layer of the inner layer substrate 3a are arranged so as to sandwich the single wire pattern 11c, and the conductor pattern 2b and the inner layer pattern 2a are arranged. An insulation distance 13 is formed between the two. That is, the shielded wire pattern 11a and the single wire pattern 11c arranged on the same adhesive layer 5 of the cloth layer 6 are arranged between the ground layers having different insulation distances. Therefore, it is possible to perform two types of impedance control for one wire layer. Therefore, it is possible to provide a multi-wire wiring board capable of controlling a plurality of types of impedances without increasing the number of wire layers and inner layers.

(Modification example)
In the multi-wire wiring board of the present embodiment, the other wire pattern 11a shielded by the other wire pattern 11b is arranged so as to intersect the upper side of the wire pattern 11a a plurality of times. It may be shielded by 11b.

Specifically, as shown in FIGS. 1 (a) to 1 (c), other line patterns are arranged so as to form a meander shape, a zigzag shape, a combination of any of these, or a combination of these. May be good. FIG. 1 (a) shows an example in which other line patterns are arranged in a meander shape, and FIG. 1 (b) shows a combination of other line patterns in which the meander-like line patterns are shifted in the vertical and horizontal directions. FIG. 1 (c) shows an example in which other line patterns are arranged in combination with the zigzag-shaped line patterns shifted in the lateral direction.

As a result, it is possible to wire the same adhesive layer 5, and moreover, another cloth pattern 11b can secure a sufficient shielding effect with respect to the shielded cloth pattern 11a.

Hereinafter, the present invention will be described based on examples, but the present invention is not limited to the present examples.

As an insulating substrate with metal foil, an inner layer pattern is formed on a double-sided copper-clad laminate MCL-I-671 (manufactured by Hitachi Kasei Co., Ltd., trade name) using a glass cloth polyimide resin by an ordinary etching method, and the inner layer substrate is formed. Made. At this time, guide patterns for alignment were formed at the four corners of the inner layer pattern at the same time. Next, a glass cloth polyimide resin prepreg GIA-671N (manufactured by Hitachi Kasei Co., Ltd., trade name) having a finished thickness of 55 μm was pressed and cured on both sides of the substrate to form the insulating layer 4.

Next, AS-U01 (manufactured by Hitachi Kasei Co., Ltd., trade name) having a thickness of 80 μm was hot-roll laminated on both sides of the substrate as an adhesive layer for fixing wires under the conditions of a roll temperature of 100 ° C. and a feed rate of 0.4 m / min. The adhesive layer was formed, and the wire layer was formed.

Subsequently, HAW (manufactured by Hitachi Kasei Co., Ltd., trade name), which is an insulating coated wire having a wire diameter of 0.065 mm and a polyimide coating layer, is laid on the wire layer from which the release-treated PET film of AS-U01 has been peeled off. The signal pattern was laid out while applying ultrasonic heating by the machine to form a wire pattern. At this time, before the line of the product pattern, the line pattern was formed at the positions corresponding to the alignment guide patterns formed at the four corners of the inner layer pattern, and the inner layer pattern was aligned with the guide pattern.

Next, a cloth shielded with HAW (manufactured by Hitachi Kasei Co., Ltd., trade name), which is an insulating coated wire having a wire diameter of 0.065 mm and a polyimide coating layer, on the same adhesive layer that formed the signal pattern. A line pattern was formed. The shielded wiring pattern was formed by shifting the meander pattern of the wiring pitch of 12 mils or the meander pattern of 25 mils by 12 mils.

Then, following the wire, light irradiation of 500 mJ / cm ² was performed on both sides by a high-pressure mercury lamp. Next, the wire-lined substrate after wire-laying was heat-pressed using silicon rubber as a cushioning material at 130 ° C. for 30 minutes under the conditions of 20 kgf / cm ² (1.96 MPa). Subsequently, a high-pressure mercury lamp was used to irradiate both sides with light at 3 J / cm ² to cure the adhesive layer.

Next, two glass cloth polyimide resin prepregs (manufactured by Hitachi Chemical Co., Ltd., GIA-671) having a finished thickness of 55 μm, and copper foils having a finished thickness of 18 μm were placed on both sides, pressed and cured.

Subsequently, after making holes at necessary locations, pretreatment such as hole cleaning is performed, and then the film is immersed in an electroless copper plating solution to perform through-hole plating to a thickness of 25 μm, and then a circuit is formed on the surface. The multi-wire wiring board (not shown) was completed.

As in the conventional case, the multi-wire wiring board that controls two types of different characteristic impedances requires four wiring layers. On the other hand, in the case where the wire pattern shielded by the same adhesive layer is formed as in this embodiment, the cloth layer can be reduced to two layers. In addition, it has been possible to provide a multi-wire wiring board capable of suppressing the cost index from 100 in the past to 80.

1 a ... Insulation substrate 2 ... Inner layer pattern (including 2a and 2b) or conductor pattern 2a ... Inner layer pattern 2b ... (as ground layer) Inner layer pattern 3 ... (including 3a and 3b) inner layer substrate 3a ... Inner layer substrate 3b ... Inner layer substrate 4 ... Insulation layer 5 ... Adhesive layer 6 ... Wire layer 7 ... (Including 7a and 7b) Insulation coating wire 7a ... Shielded insulation coating wire 7b ... Insulation coating wire 8 for shielding ... Wire 9 ... Insulation coating 10 ... Insulation layer 11 ... (including 11a, 11b, 11c) Wire pattern or signal pattern 11a ... Shielded wire pattern or the wire pattern or signal pattern 11b ... Shielding wire Pattern or other wire pattern 11c ... (single) wire pattern or signal pattern 12 ... Multi-wire wiring board 13 ... Insulation distance 14 ... (between 2a and 2b) Insulation distance 14 ... (between 2a and 7b)

Claims (2)

An inner layer substrate having an inner layer pattern formed by circuit processing a metal foil bonded on an insulating substrate, a wire layer laminated on the inner layer substrate and having an insulating layer and an adhesive layer, and a wire layer of the wire layer. It has a wire pattern formed by laying an insulating coated wire on an adhesive layer, and a conductor pattern laminated on the cloth pattern via an insulating layer.
On the same adhesive layer of the wire layer, another insulating coated wire arranged so as to intersect the upper side of the wire pattern formed by laying the insulating coated wire a plurality of times with continuous insulating coated wires is applied. A multi-wire wiring board in which a wire pattern shielded by a wire pattern formed by wire and a single wire pattern that is not shielded by other wire patterns are mixed and arranged. Oite to claim 1, multi-wire other insulating coated wire wiring pattern formed by wired and is meander-shaped, is disposed so as to be zigzag, a combination of a combination or these with each other one of these Wiring board.

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