JP4587974B2 - Manufacturing method of multilayer printed wiring board - Google Patents

Description

  The present invention relates to a multilayer printed wiring board.

In recent years, the performance of electronic devices has been remarkably improved. In particular, communication devices and computers are required to cope with higher frequencies in addition to higher operating speeds. There is also a demand for miniaturization.
For this reason, printed wiring boards mounted on these devices are also required to have high speed and low loss signal transmission, high wiring density, thinning, light weight, and the like. These requirements for the printed wiring board are directly directed to further lowering the dielectric constant, lowering the dielectric loss tangent, reducing the thickness, and reducing the weight of the substrate material. As a means for solving these requirements, a multilayer printed wiring board by a build-up method has been adopted for a long time.

In multilayer printed wiring boards using the conventional build-up method, the thermosetting resin or prepreg such as epoxy resin alone, glass woven fabric base epoxy resin prepreg, or aramid nonwoven fabric base epoxy resin prepreg is generally used as an interlayer insulating material. These interlayer insulating materials are laminated on a core printed wiring board such as FR-4 material to obtain a multilayer printed wiring board.
When using an epoxy resin alone as an interlayer insulating material, a multilayer printed wiring board is formed by heat-press molding a copper foil with an epoxy resin on the core printed wiring board surface, or an epoxy resin is coated on the core printed wiring board surface. Then, a copper foil is placed thereon and integrated by heating and pressing to form a multilayer printed wiring board. On the other hand, when glass woven fabric base material epoxy resin prepreg, aramid non-woven fabric base material epoxy resin prepreg, etc. are used as an interlayer insulating material, these prepregs are placed on the core printed wiring board surface, and copper foil is stacked and heat-press molded To form a multilayer printed wiring board. A structure and a manufacturing method in which an interlayer connection of printed wiring is made of plated copper filled in a via hole opened by a carbon dioxide laser on the insulating layer formed in this manner are mainly used.

Multi-layer printed wiring boards that use such thermosetting resins as insulating materials are superior in rigidity and heat resistance, and because they use insulating materials consisting of only low-permittivity, low-dielectric-tangent, and lightweight organic substances,・ Excellent low loss signal transmission and light weight. In addition, since it does not contain a difficult-to-process component such as a glass woven fabric, it is possible to process fine via holes and obtain a high-density multilayer printed wiring board.
However, the multilayer printed wiring board is required for electronic devices because thermosetting resins used for insulating materials, including those using polyimide resin, do not necessarily have sufficient low dielectric constant and low dielectric loss tangent characteristics. It does not fully satisfy the high-frequency characteristics.

On the other hand, a multilayer printed wiring board using a liquid crystal polymer, which is a thermoplastic resin, as an interlayer insulating material has also been proposed (see, for example, Patent Documents 1 and 2). Since the liquid crystal polymer is excellent in low dielectric constant and low dielectric loss tangent characteristics, it is excellent in high-speed and low-loss signal transmission in the high-frequency region of the multilayer printed wiring board.
However, in order to reduce the thickness of multilayer printed wiring boards, which are required to achieve higher density and miniaturization of multilayer printed wiring boards, the heat resistance of the insulating layer is required, but liquid crystal polymers are heat resistant. Sex is not always enough.

By the way, the multilayer printed wiring board generally has a resin-coated copper foil, a prepreg, and a resin piece and a glass piece that easily fall off from the end face of the substrate (so-called “powder-off”). It remains on the surface of the metal foil, forms dents, makes it difficult to form fine wiring, and there is also a problem that even if the fine wiring can be formed, malfunction of the mounted device is caused.
JP-A-8-97565 JP 2004-31926 A

  As mentioned above, it is not always satisfactory with any conventional multilayer printed wiring board that can achieve higher density and miniaturization of multilayer printed wiring boards and simultaneously achieve heat resistance and excellent high frequency characteristics. No good thing has been obtained.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a multilayer printed wiring board capable of simultaneously realizing heat resistance and excellent high frequency characteristics.

Method for manufacturing a multilayer printed wiring board according to the present invention is a method of manufacturing a multilayer printed wiring board and the wiring circuit layers and insulating layers are alternately laminated,
A double-sided circuit board form respective wiring circuit layers on both surfaces of the polyimide resin layer, characterized by having a step of forming a liquid crystal polymer layers on both sides of that the double-sided wiring board as a core substrate.

A method for manufacturing a multilayer printed wiring board according to the present invention, the side opposite to the side where the adjacent core substrate of the liquid crystal polymer layer, and characterized by forming a liquid crystal polymer layer through the further wiring circuit layer To do.

Moreover, the manufacturing method of the multilayer printed wiring board concerning this invention is characterized by the roughness of the interface of the said polyimide resin layer and the said liquid crystal polymer layer being 4-6 micrometers.

Moreover, the manufacturing method of the multilayer printed wiring board concerning this invention is characterized by the roughness of the interface of the said polyimide resin layer and the said liquid crystal polymer layer being less than 4 micrometers.

Moreover, the method for producing a multilayer printed wiring board according to the present invention is characterized in that the laminated surface of the liquid crystal polymer layer is surface-treated in advance.

  The multilayer printed wiring board of the present invention is a laminated structural unit in which one insulating layer of two insulating layers adjacent to each other via a wiring circuit layer is a polyimide resin layer, and the other insulating layer is a liquid crystal polymer layer. Therefore, both the heat resistance of the multilayer printed wiring board and the excellent high frequency characteristics can be achieved.

  Preferred embodiments of the multilayer printed wiring board according to the present invention will be described below.

The multilayer printed wiring board has a structure in which a plurality of wiring circuit layers (wiring circuits, conductor layers) and a plurality of insulating layers are alternately stacked.
The multilayer printed wiring board of the present invention is, for example, as shown in FIG. 1, in the multilayer printed wiring board 10 having the above laminated structure, of the two insulating layers 14 a and 14 b adjacent to each other via the wiring circuit layer 12. One insulating layer is a polyimide resin layer, and the other one insulating layer includes a laminated structural unit 16 that is a liquid crystal polymer layer. The multilayer structure unit 16 may extend over the entire multilayer structure of the multilayer printed wiring board 10, or may be provided at one or more appropriate locations in the entire multilayer structure.
In addition, although it is preferable to use a polyimide resin as the material of one insulating layer 14a, it is not restricted to this, The heat resistance of an insulating layer is ensured, and it has each characteristic of moderate low dielectric constant and a low dielectric loss tangent. If it is a thing, you may use another thermosetting resin. On the other hand, it is preferable to use a liquid crystal polymer as the material of the other insulating layer 14b. However, the present invention is not limited to this, and other thermoplastic resins may be used as long as they have excellent characteristics of low dielectric constant and low dielectric loss tangent. It may be used.
Further, as the material of the wiring circuit layer 12, an appropriate highly conductive metal can be used, but it is particularly preferable to use a copper foil.
When the insulating layer 14a is a polyimide resin layer and the insulating layer 14b is a liquid crystal polymer layer, the insulating layer 14a can have a thickness of about 5 to 100 μm, for example, and the insulating layer 14b can have a thickness of 10 to 100 μm, for example. Can be about. Moreover, the thickness of the wiring circuit layer 12 can be about 3 to 35 micrometers, for example.

The polyimide resin is a polyimide precursor resin obtained by appropriately selecting a known diamino compound and tetracarboxylic acid or anhydride thereof, and combining them in an organic solvent so as to obtain desired characteristics. Obtainable. In this case, the main component is a polyimide resin or polyamide resin having an imide bond in the molecule, but it is not necessarily a single polyimide resin, and may be a mixture with other resins.
As the polyimide resin applied to the present invention, those having a linear expansion coefficient in a certain range are preferable from the viewpoint of dimensional stability. The linear expansion coefficient is preferably in the range of 0~35 × 10 ^-6 / ℃, the range of ^{1 × 10 -6 ~25 × 10 -6} / ℃ is more preferable.
As the polyimide resin of the insulating layer, it is convenient to use a commercially available polyimide film or a copper clad laminate. When a polyimide film is used, a film formed by a known method such as sputter plating can be used. Moreover, in the case of a copper clad laminated board, arbitrary wiring circuits can be formed and used by a well-known method. As the polyimide film, Apical AH, NPI (manufactured by Kaneka Co., Ltd.), Upilex S (manufactured by Ube Industries, Ltd.), Kapton (manufactured by Toray DuPont Co., Ltd.), or the like can be used. Moreover, as a copper clad laminated board, Espanesque S series and M series (all are the Nippon Steel Chemical Co., Ltd. product) can be used.

The liquid crystal polymer forms an optically anisotropic melt phase. The liquid crystal polymer is not particularly limited in its kind, but a so-called wholly aromatic liquid crystal polymer, that is, a liquid crystal polymer that does not contain an aliphatic long chain and is substantially composed only of an aromatic is preferable, and among them, A polyester composed of 6-hydroxy-2-naphthoic acid and p-hydroxybenzoic acid is more preferable. In addition, the liquid crystal polymer may be a mixture in which an appropriate kind of liquid crystal material is combined.
The liquid crystal polymer used for the wiring substrate preferably has a certain level of heat resistance and linear expansion coefficient in order to maintain a balance with the polyimide resin used together with the liquid crystal polymer. A preferable range of the melting point of the liquid crystal polymer is 250 to 350 ° C., and a preferable range of the linear expansion coefficient is 1 × 10 ^{−6 to} 25 × 10 ⁻⁶ / ° C.
As the liquid crystal polymer of the insulating layer, it is convenient to use a commercially available liquid crystal polymer film or a copper clad laminate. When a liquid crystal polymer film is used, a film formed by a known method such as sputter plating can be used. Also, in the case of a copper clad laminate, an arbitrary wiring circuit is formed and used by a known method. As the liquid crystal polymer film, Bexter (manufactured by Kuraray Co., Ltd.) or the like can be used. Moreover, as a copper clad laminated board, Espanesque L series (made by Nippon Steel Chemical Co., Ltd.) can be used.

The multilayer printed wiring board of the present invention configured as described above has an excellent balance of characteristics due to the combination of the good heat resistance of the polyimide resin and the excellent high frequency characteristics of the liquid crystal polymer.
Moreover, since the insulating layer of the present invention does not contain a reinforcing material such as a glass woven fabric or an aramid nonwoven fabric, the resulting multilayer printed wiring board is excellent in densification, thinning, and weight reduction. Moreover, the occurrence of yield loss due to powder falling is reduced.

In addition, the multilayer printed wiring board of the present invention is, for example, as shown in FIG. 2, in the laminated structural unit 16a, the side opposite to the side adjacent to the polyimide resin layer (insulating layer 14a) of the liquid crystal polymer layer (insulating layer 14b). In addition, the liquid crystal polymer layer (insulating layer 14c) may be provided via the wiring circuit layer 12a.
In the case of such a structure in which the liquid crystal polymers are laminated side by side, there is a concern about the positioning of the wiring circuit due to heating and pressurization in the manufacturing process of the multilayer printed wiring board. 14b is preferably 5 ° C. or more, more preferably 10 to 40 ° C. higher than the liquid crystal polymer layer 14c. The melting point of the liquid crystal polymer in the present invention refers to a melting (endothermic) peak temperature measured by heating the liquid crystal polymer at a rate of temperature increase of 10 ° C./min with a differential scanning calorimeter (DSC).
The multilayer printed wiring board including the laminated structural unit 16a configured as described above can easily realize higher-order multilayering of the printed wiring board having the laminated structural unit 16 as a skeleton structure.

Further, the multilayer printed wiring board according to the present invention has a boundary surface (indicated by an arrow A in FIG. 1) between the polyimide resin layer (insulating layer 14a) and the liquid crystal polymer layer (insulating layer 14b) in the laminated structural units 16 and 16a. )) Roughness (Rz) of 4 to 6 μm, without causing adverse effects on high-speed and low-loss signal transmission in the high-frequency region, which can occur when the roughness of the interface is significantly large. Adhering without gaps, sufficient interlayer adhesion strength can be ensured.
Further, the roughness (Rz) of the boundary surface may be less than 4 μm, preferably 1 to 3 μm. In this case, the adverse effect on high-speed and low-loss signal transmission performance in the high-frequency region can be avoided more reliably. be able to.
The roughness of the boundary surface is controlled by, for example, preliminarily forming a polyimide resin layer (insulating layer 14a) when the wiring layer 12 is formed by etching and patterning a conductor layer previously laminated on the polyimide resin layer (insulating layer 14a). ) By a suitable method such as changing the surface roughness of a conductor layer such as a copper foil laminated on the surface, in other words, changing the surface roughness of the surface (laminated surface) on which the liquid crystal polymer layer (insulating layer 14b) is laminated. be able to.

In addition, the multilayer printed wiring board according to the present invention includes a liquid crystal polymer layer 14b constituting the boundary surface A between the polyimide resin layer (insulating layer 14a) and the liquid crystal polymer layer (insulating layer 14b) in the laminated structural units 16 and 16a. When the laminated surface facing the polyimide resin layer 14a and the laminated surface of the liquid crystal polymer layer 14c facing the liquid crystal polymer layer 14b are respectively surface-treated in advance, the layers are closely adhered to each other and good interlayer adhesion strength is obtained. be able to.
In particular, when the surface roughness is less than 4 μm as described above, the surface treatment is performed to achieve a good balance between reducing the adverse effects on high-speed and low-loss signal transmission and ensuring the interlayer adhesion strength in a high-frequency region. It is possible and more preferable.
The surface treatment is performed before the lamination integration process. As the surface treatment method, etching with an alkali mixed solution or etching with plasma is desirable.
In the vacuum hot pressing process, for example, the maximum temperature is controlled in the range of 220 to 300 ° C. and the pressing pressure is controlled in the range of 4 to 8 MPa. In the lamination process, for example, the maximum temperature is set to 200 to 300 ° C. By controlling the laminating pressure (linear pressure) in the range of 2 to 200 kN / m within this range, it is possible to achieve sufficient interlayer adhesion strength by suitably softening or flowing the thermoplastic resin. .

Hereinafter, the manufacturing method of the multilayer printed wiring board of this invention is demonstrated.
FIG. 7 is a process diagram showing a method for producing a four-layer printed wiring board (corresponding to Example 5 described later) centering on a polyimide resin layer.
First, a double-sided copper-clad laminate 502 in which a polyimide resin layer is used as an insulating layer and copper foils 503 are laminated on both sides thereof is prepared (FIG. 7A). As the double-sided copper-clad laminate 502, a commercially available double-sided copper-clad laminate can be used. A wiring circuit layer 504 is formed on the double-sided copper-clad laminate 502 by an arbitrary method (FIG. 7B). For example, the wiring circuit layer 504 may be formed on a polyimide film by sputter plating. The thicknesses of the polyimide resin layer and the wiring circuit layer (copper foil) are preferably as described above.
Next, a single-sided copper-clad laminate 506 having a liquid crystal polymer as an insulating layer is thermocompression bonded to both sides of the double-sided wiring board 505 thus formed (FIG. 7C). Reference numeral 507 denotes a hot press hot platen. Here, it is preferable to use liquid crystal polymers having the same melting point in order to satisfactorily fill the liquid crystal polymer between the circuits. The preferable melting point of the liquid crystal polymer is in the range of 250 to 350 ° C., and the heating temperature during heating and pressurization is preferably 0 to 50 ° C. lower than the melting point of the liquid crystal polymer. Moreover, pressurization is preferably performed at 4 to 8 MPa for 5 to 60 minutes. Here, if the heating temperature at the time of heating / pressurizing the liquid crystal polymer is lower by 50 ° C. or more than the melting point of the liquid crystal polymer, the wiring circuit of the wiring board may be deformed, and the pressurizing range is less than 4 MPa. There is a risk of insufficient filling of the liquid crystal polymer between the wiring circuits. On the other hand, when the heating temperature for the liquid crystal polymer is higher than the melting point of the liquid crystal polymer or the pressure range exceeds 8 MPa, the liquid crystal polymer oozes out of the substrate (wiring substrate), Voids may be generated in the liquid crystal polymer layer.
After heating and pressurization, the substrate is cooled to obtain a stacked body 508 (FIGS. 7D and 7E). These manufacturing conditions are the same in the similar manufacturing method described below.

  The obtained laminated body 508 forms a through hole 509 by a known method such as an NC drill (FIG. 7F), performs a desmear process, and forms a panel plating 510 (FIG. 7G). Then, the outermost layer 511 is etched and patterned by a tenting method, the wiring circuit layer 512 is formed, and the solder resist layer 513 is formed, so that the multilayer printed wiring board 501 can be obtained (FIG. 7H).

FIG. 8 is a process diagram showing a method for producing a four-layer printed wiring board (corresponding to Example 6 to be described later) centering on a polyimide resin layer by a roll-to-roll method.
First, a double-sided copper-clad laminate 602 in which a roll-shaped polyimide resin layer is used as an insulating layer and copper foils 603 are laminated on both sides thereof is prepared, a wiring circuit layer 604 is formed by an arbitrary method, and a double-sided wiring board 605 is formed. Is obtained (FIG. 8 (a)). As the double-sided copper-clad laminate 602, a commercially available double-sided copper-clad laminate can be used. Note that the wiring circuit layer 604 may be formed on the polyimide film by an arbitrary method such as sputter plating. The thicknesses of the polyimide resin layer and the wiring circuit layer (copper foil) are preferably as described above.

Next, on both sides of the double-sided wiring board 605 formed in this way, two roll-shaped single-sided copper-clad laminates 606 having a liquid crystal polymer as an insulating layer are heat-pressed to obtain a laminate 608 (FIG. 8B). ), FIG. 8 (c)). Reference numeral 607 indicates a roll. Here, it is preferable to use liquid crystal polymers having the same melting point in order to satisfactorily fill between the circuits on both sides. The melting point range of the liquid crystal polymer to be used is the same as in the press process, but the heating temperature at the time of heating and pressurization is preferably 0 to 80 ° C. lower than the melting point of the liquid crystal polymer. The pressurization is preferably performed by passing the roll at a laminate pressure (linear pressure) of 2 to 200 kN / m. These manufacturing conditions are the same in the similar manufacturing method described below. Here, if the heating temperature at the time of heating / pressurizing the liquid crystal polymer is lower by 80 ° C. or more than the melting point of the liquid crystal polymer, the wiring circuit of the wiring board may be deformed, and the pressurizing range is less than 2 kN / m. Otherwise, the liquid crystal polymer may be insufficiently filled between the wiring circuits. On the other hand, if the heating temperature for the liquid crystal polymer is higher than the melting point of the liquid crystal polymer, or if the pressure range exceeds 200 kN / m, the liquid crystal polymer oozes out of the substrate, or the liquid crystal polymer Voids may occur in the layer.
The obtained laminate 608 is cut and then through-holes 609 are formed in the same manner as described above (FIG. 8D), desmear treatment is performed, and panel plating 610 is formed (FIG. 8D e)) Next, the outermost layer 611 is etched and patterned by a tenting method to form a wiring circuit layer 612 and further a solder resist layer 613 to obtain a multilayer printed wiring board 601 (see FIG. 7 (f)).

FIG. 9 is a process diagram showing a method for producing a four-layer printed wiring board (corresponding to Example 7 described later) centering on the same polyimide resin layer as FIG.
First, a double-sided copper-clad laminate 702 in which a polyimide resin layer is used as an insulating layer and copper foils 703-1 and 703-2 are laminated on both sides thereof is prepared (FIG. 9A). As the double-sided copper-clad laminate 702, a commercially available double-sided copper-clad laminate can be used. Two sheets of this double-sided copper-clad laminate 702 are prepared (the other one is indicated by reference numeral 702 ′), and the wiring circuit layer 704- is formed on one side of each of the double-sided copper-clad laminates 702 and 702 ′ by an arbitrary method. 1 ′ and 704-2 are formed (FIG. 9B). For example, a wiring circuit layer may be formed on a polyimide film by sputter plating. The thicknesses of the polyimide resin layer and the wiring circuit layer (copper foil) are preferably as described above.
On the other hand, the copper foil 706 on both sides of the double-sided copper-clad laminate 705 having a liquid crystal polymer layer 707 of the same size as the double-sided copper-clad laminates 702 and 702 ′ as an insulating layer is removed by etching and immersed in an alkaline mixed aqueous solution. A liquid crystal polymer layer 707 is obtained (FIG. 9C).
Next, the surface-treated liquid crystal polymer layer 707 is sandwiched between the double-sided copper-clad laminates 702 and 702 ′ facing the wiring circuit layers 704-2 and 704-1 ′, and thermocompression bonded (FIG. 9D). . Reference numeral 708 indicates a hot platen. After heating and pressurization, the substrate is cooled to obtain a laminate 709 (FIGS. 9E and 9F).
The obtained laminate 709 forms a through hole 710 by a known method such as an NC drill (FIG. 9G), performs a desmear process, and forms a panel plating 711 (FIG. 9H). Then, the outermost layer 712 is etched and patterned by a tenting method, the wiring circuit layer 713 is formed, and the solder resist layer 714 is formed, so that the multilayer printed wiring board 701 can be obtained (FIG. 9I).

FIG. 10 is a process diagram showing a method for producing a four-layer printed wiring board (corresponding to Example 8 to be described later) centering on a polyimide resin layer similar to FIG.
First, two double-sided copper-clad laminates 802 and 802 ′ in which a roll-shaped polyimide resin layer is used as an insulating layer and copper foils 803 and 803 ′ are laminated on both sides thereof are prepared. 804 and 804 ′ are formed to obtain double-sided wiring boards 805 and 805 ′ (FIG. 10A). Commercially available double-sided copper-clad laminates can be used as the double-sided copper-clad laminates 805 and 805 ′. Note that the wiring circuit layers 804 and 804 ′ may be formed on the polyimide film by an arbitrary method such as sputter plating. The thicknesses of the polyimide resin layer and the wiring circuit layer (copper foil) are preferably as described above.
On the other hand, after removing the copper foil on both sides of the double-sided copper-clad laminate 806 having a liquid crystal polymer layer of the same size as that of the double-sided copper-clad laminates 805 and 805 'as an insulating layer, the exposed surface is subjected to plasma treatment to obtain a liquid crystal A polymer layer 807 is obtained (FIG. 10B).
Next, the surface-treated liquid crystal polymer layer 807 is sandwiched between double-sided copper-clad laminates 805 and 805 ′ facing the wiring circuit layers 804 and 804 ′, and thermocompression bonded (FIG. 10C). Reference numeral 808 indicates a roll. After heating and pressurizing, the substrate is cooled to obtain a laminate 809.
The obtained laminated body 809 is cut and then through holes 810 are formed in the same manner as described above (FIG. 10D), desmear treatment is performed, panel plating 811 is formed, and then the tenting method By etching and patterning the outermost layer 812, a wiring circuit layer 813 is formed, and further a solder resist layer 814 is formed, whereby a multilayer printed wiring board 801 can be obtained (FIG. 10 (e), FIG. 10 (f) )).

FIG. 11 is a process diagram showing a method for manufacturing an eight-layer printed wiring board (corresponding to Example 9 described later) centered on a polyimide resin layer.
First, two double-sided copper-clad laminates 902 in which a polyimide resin layer is used as an insulating layer and copper foils 903-1 are laminated on both sides thereof are prepared (FIG. 11A). Only display.). Commercially available double-sided copper-clad laminates can be used as the double-sided copper-clad laminates 902 and 902 ′. Wiring circuit layers 904-1, 904-1 ′, 904-2 and 904-2 ′ are formed on both surfaces of the double-sided copper-clad laminates 902 and 902 ′ by an arbitrary method (FIG. 11B). For example, a wiring circuit layer may be formed on a polyimide film by sputter plating. The thicknesses of the polyimide resin layer and the wiring circuit layer (copper foil) are preferably as described above.
On the other hand, the copper foil 906 on both sides of the double-sided copper-clad laminate 905 having a liquid crystal polymer layer 907 of the same size as the double-sided copper-clad laminate 902, 902 ′ as an insulating layer is removed by etching, and immersed in an alkali mixed aqueous solution. A liquid crystal polymer layer 907 is obtained (FIG. 11C).
Next, the surface-treated liquid crystal polymer layer 907 is sandwiched between the double-sided copper-clad laminates 902 and 902 ′ and thermocompression bonded (FIG. 11 (d)). Reference numeral 908 indicates a hot platen. After heating and pressurization, the substrate is cooled to obtain a laminate 909 (FIG. 11E).
A single-sided copper-clad laminate 910, 910 ′ in which the resin surfaces 911, 911 ′ of the liquid crystal polymer are plasma-treated is prepared, and the resin surfaces 911, 911 ′ are opposed to each other on both sides of the laminate 909 (FIG. 11F). ) To obtain a laminate 912 by heating and pressing (FIG. 11 (g)).
The laminated body 912 is etched 913 (FIG. 11 (h)), and then a blind via hole 914 is formed (FIG. 11 (i)). After the desmear treatment, a plating layer 915 is formed (FIG. 11 (j)), and a wiring circuit layer 916 is further formed (FIG. 11 (k)). 11 (f) to (i) are performed again, through holes 918 are formed in the obtained laminate 917 (FIG. 11 (l)), and desmear treatment is performed to obtain panel plating 919 ( FIG. 11 (m)). Then, the outermost layer 920 is etched and patterned by a tenting method, a wiring circuit layer 919 is formed, a solder resist layer 921 is formed, and an eight-layer printed wiring board 901 is obtained (FIG. 11 (n)).

FIG. 12 is a process diagram showing a method for producing an 8-layer printed wiring board (corresponding to Example 10 described later) centering on a polyimide resin layer similar to FIG.
First, two double-sided copper-clad laminates 1002 and 1002 in which a roll-shaped polyimide resin layer is an insulating layer and copper foils 1003-1, 1003-2, 1003-1 ′, and 1003-2 ′ are laminated on both sides thereof. 'Is prepared, wiring circuit layers 1004-1, 1004-2, 1004-1', 1004-2 'are formed by an arbitrary method, and double-sided wiring boards 1005, 1005' are obtained (FIG. 12A). As the double-sided copper-clad laminates 1005 and 1005 ′, commercially available double-sided copper-clad laminates can be used. Note that the wiring circuit layers 1004-1, 1004-2, 1004-1 ′, and 1004-2 ′ may be formed on the polyimide film by an arbitrary method such as sputter plating. The thicknesses of the polyimide resin layer and the wiring circuit layer (copper foil) are preferably as described above.
On the other hand, after removing the copper foil on both sides of the double-sided copper-clad laminate 1006 having a liquid crystal polymer layer of the same size as that of the double-sided copper-clad laminates 1005 and 1005 ′ as an insulating layer, the surface is subjected to plasma treatment and the liquid crystal polymer layer 1007 Is obtained (FIG. 12B).
Next, the surface-treated liquid crystal polymer layer 1007 is sandwiched between the double-sided copper-clad laminates 1005 and 1005 ′, thermocompression-bonded, and then cooled to obtain a laminate 1009 (FIG. 12C). Reference numeral 1008 indicates a hot platen.
A single-sided copper-clad laminate 1010, 1010 ′ in which the resin surfaces of the liquid crystal polymers 1011 and 1011 ′ are plasma-treated is prepared, and the resin surfaces of the liquid crystal polymers 1011 and 1011 ′ are overlapped on both surfaces of the laminate 1009, The laminated body 1012 is obtained by applying pressure (FIG. 12 (d)).
Next, the laminated body 1012 is etched 1014, and then a blind via hole 1015 is formed (FIG. 12E). After the desmear process, a plating layer 1016 electrically connected to the wiring circuit layers 1004-1 and 1004-2 ′ is formed (FIG. 12 (f)), and a wiring circuit layer 1017 is further formed (FIG. 12 (g)). . 12D to 12E are performed again, through holes 1019 are formed in the obtained laminate 1018 (FIG. 12H), and desmearing is performed to obtain panel plating 1020 ( FIG. 12 (i)). Then, the outermost layers 1021 and 1021 ′ are etched and patterned by a tenting method to form a wiring circuit layer 1022, and a solder resist layer 1023 to obtain an eight-layer printed wiring board 1001 (FIG. 12 (j)).

  The present invention will be further described with reference to examples and comparative examples. In addition, this invention is not limited to the Example demonstrated below.

Example 1
The multilayer printed wiring board 101 whose sectional view is shown in FIG. 3 will be described.
The multilayer (four-layer) printed wiring board 101 uses, as a basic structure 105, one polyimide resin layer 103 and two liquid crystal polymer layers 104 as insulating layers, and on both sides of the polyimide resin layer 103, A wiring circuit layer 102 is formed, and a liquid crystal polymer layer 104 is provided as an insulating layer on both sides thereof. The polyimide resin layer 103 and the wiring circuit layer 102 on both sides thereof are made from a double-sided copper-clad laminate (trade name Espanex S (Espanex is a registered trademark) manufactured by Nippon Steel Chemical Co., Ltd., product number: SB12-25-12CE). Is formed. That is, the polyimide resin layer 103 is a polyimide resin layer derived from the double-sided copper-clad laminate, and the wiring circuit layer 102 is formed by processing a copper foil derived from the double-sided copper-clad laminate. .

In the multilayer printed wiring board 101 of FIG. 3, the liquid crystal polymer layer 104 as the basic structure 105 and the wiring circuit layer 109 provided adjacent thereto are obtained, for example, by circuit processing of the double-sided copper-clad laminate. A single-sided copper-clad laminate (hereinafter referred to as single-sided copper-clad laminate LX. This is referred to as a single-sided copper-clad laminate LX. Melting point of the liquid crystal polymer). : 280 [deg.] C.), and a copper foil can be formed by circuit processing. In FIG. 3, the wiring circuit layer 109 has a wiring circuit layer 106 on the surface thereof, and also has a plated through hole 107 that electrically connects each layer and a solder resist layer 108 formed in the outermost layer. ing.

Here, the wiring circuit layer 106 is composed of the wiring circuit layer 109 and the same plated copper 110 as the plated through hole 107. The thickness of the liquid crystal polymer layer 104 is 25 μm, the thickness of the wiring circuit layer 109 is 12 μm, and the thickness of the polyimide resin layer 103 is 25 μm. The through hole 107 has a hole diameter of 0.15 mm, the plated copper 110 has a thickness of 8 μm, and the solder resist layer 108 has a thickness of 25 μm. The basic design rule of the wiring circuit layer is that the wiring circuit layer 102 has a line / space of 50/50 μm, the wiring circuit layer 106 has 75/75 μm, and the through-hole land 111 of each wiring circuit layer 102 and 106 has φ0.3 mm. The roughness (Rz) of the two boundary surfaces 112 and 112 formed between the polyimide resin layer 103 and the two liquid crystal polymer layers 104 and 104 is 4.5 μm and 4.9 μm as a result of cross-sectional observation. there were. Also. The total thickness of the four-layer printed wiring board 101 was about 125 μm.

(Example 2)
The multilayer printed wiring board 201 whose sectional view is shown in FIG. 4 will be described.
The multilayer (four-layer) printed wiring board 201 uses two polyimide resin layers 203 and 203 ′ and one liquid crystal polymer layer 204 as insulating layers, and is provided on both sides of each polyimide resin layer 203 and 203 ′. Wiring circuit layers 208 and 208 ′ are formed, and a liquid crystal polymer layer 204 is provided as an insulating layer between the polyimide resin layer 203 and the polyimide resin layer 203 ′. The polyimide resin layer 203 and the wiring circuit layers 208 and 208 ′ on both sides thereof are formed from a double-sided copper-clad laminate (trade name Espanex M product number: MB12-12-12FR manufactured by Nippon Steel Chemical Co., Ltd.). . That is, the polyimide resin layers 203 and 203 ′ are polyimide resin layers derived from the double-sided copper-clad laminate, and the wiring circuit layers 208 and 208 ′ are obtained by circuit processing of copper foil derived from the double-sided copper-clad laminate. It is formed.

  The basic structure 205 of the multilayer printed wiring board 201 in FIG. 4 is a wiring formed by processing a circuit on only one side of a double-sided copper-clad laminate having polyimide resin layers 203 and 203 ′ as insulating layers on both sides of a liquid crystal polymer layer 204. The circuit layers 202-2 and 202-1 ′ and the liquid crystal polymer layer 204 were laminated and integrated so as to face each other, and then the outer wiring circuit layer 208 was formed. Here, the liquid crystal polymer layer 204 is a double-sided copper-clad laminate (hereinafter referred to as a double-sided copper-clad laminate LY) having a liquid crystal polymer layer having a thickness of 50 μm as an insulating layer and copper foil having a thickness of 12 μm on both sides thereof. A liquid crystal polymer film obtained by etching away a copper foil having a melting point of liquid crystal polymer: 300 ° C. was used. In FIG. 4, a wiring circuit layer 209 is provided on the surface of the outer wiring circuit layer 208, and a plated through hole 206 for electrically connecting each layer and a solder resist layer 207 formed in the outermost layer. Have.

  Here, the wiring circuit layers 202-1 and 202-2 'are the same plated copper as the wiring circuit layer 208 (Espanex M product number: MB12-12-12FR) derived from the double-sided copper clad laminate LY and the plated through hole 206. 209. The thickness of the polyimide resin layer is 12 μm, and the thickness of the copper foil derived from Espanex M is 12 μm. The through hole 206 has a hole diameter of 0.15 mm, the plated copper 209 has a thickness of 8 μm, and a solder resist film thickness of 20 μm. The basic design rules of the wiring circuit layer are as follows: wiring circuit layers 202-2 and 202-1 ′ are line / space: 50/50 μm, wiring circuit layers 202-1 and 202-2 ′ are line / space: 75/75 μm, each layer The through hole 206 is φ0.3 mm. The roughness (Rz) of the interface 210 between the polyimide resin layers 203 and 203 ′ and the liquid crystal polymer layer 204 was 2.0 μm and 1.9 μm as a result of cross-sectional observation. Also. The total thickness of the four-layer printed wiring board 201 was about 115 μm.

(Example 3)
The multilayer printed wiring board 301 whose sectional view is shown in FIG. 5 will be described.
A multilayer (8-layer) printed wiring board 301 includes liquid crystal polymer layers 303 and 303 ′ on both sides of a basic structure 302 similar to that of the second embodiment (however, there is no structure corresponding to the through hole 208 and its plated copper 209). , IVH 304 ′, wiring circuit layers 305, 305 ′, liquid crystal polymer layers 317, 317 ′, BVH 307, 307 ′, wiring circuit layers 308, 308 ′ are laminated and integrated, and the layers are electrically connected to each other. This is an eight-layer printed wiring board composed of a through hole 309 and a solder resist layer 310 formed in the outermost layer.
Liquid crystal polymer layer 303, 303 'is a liquid crystal polymer having a thickness of 25μm and the insulating layer, single-sided copper-clad laminate having a copper foil having a thickness of 9μm on one surface thereof (hereinafter referred to as single-sided copper clad laminate LX _2. The wiring circuit layers 311 and 311 ′ are formed by circuit processing of the copper foil of the single-sided copper-clad laminate. The liquid crystal polymer layers 317 and 317 ′ have a single-sided copper-clad laminate (hereinafter referred to as a single-sided copper-clad laminate LX ₃₎ having a liquid crystal polymer with a thickness of 50 μm as an insulating layer and a copper foil with a thickness of 9 μm on one side. The wiring circuit layers 313 and 313 ′ are formed by processing a copper foil of the single-sided copper-clad laminate. The IVH 304 ′ is arbitrarily provided by a known means, and can be electrically connected to other wiring circuits.

Here, the wiring circuit layers 305 and 305 ′ are composed of the wiring circuit layers 311 and 311 ′ and the plated copper 312 that is the same as the IVHs 304 and 304 ′. Similarly, the wiring circuit layers 308 and 308 ′ are composed of the wiring circuit layers 313 and 313 ′, the BVH 307 and 307 ′, and the plated copper 314 that is the same as the plated through hole 309.
The liquid crystal polymer thickness derived from the single-sided copper-clad laminate LX ₂ and the single-sided copper-clad laminate LX ₃ is 25 μm and the wiring circuit layers 313 and 313 ′ have a thickness of 9 μm, and the upper diameters of IVH304 ′, BVH307 and 307 ′ are 100 μm, The lower diameter is 90 μm, the thickness of the plated copper 314 is 8 μm, the hole diameter of the through hole 309 is 0.15 mm, the thickness of the plated copper 312 is 8 μm, and the thickness of the solder resist layer 310 is 20 μm. The basic design rules for the wiring circuit layer are as follows: the wiring / layers of the wiring circuit layers 305 and 305 ′ are 50/50 μm in all layers, the through-hole lands 315 are 0.3 mm in all layers, and the pads of IVH304 ′ and BVH307 and 307 ′ are 0. 2 mm. The roughness (Rz) of the interface 316 between the polyimide resin layer and the liquid crystal polymer layer was 2.2 μm and 2.0 μm as a result of cross-sectional observation. Also. The total thickness of the eight-layer printed wiring board 301 was about 270 μm.

Example 4
The multilayer printed wiring board 401 whose sectional view is shown in FIG. 6 will be described.
The multilayer (four-layer) printed wiring board 401 has one polyimide resin layer 403 and two liquid crystal polymer layers 404 and 407 in an insulating layer, and four wiring circuit layers 402, 406, 412, and 414. is doing. The polyimide resin layer 403 and the wiring circuit layers 402 and 414 on both sides thereof are a resin layer derived from a double-sided copper-clad laminate (Espanex S product number: SB18-25-18CE) having a polyimide resin layer as an insulating layer and its copper foil It is a wiring circuit layer formed by processing the circuit. Further, the liquid crystal polymer layer 404 and the wiring circuit layer 406 adjacent to the polyimide resin layer 403 are a single-sided copper clad laminate (hereinafter referred to as “this”) having a 18 μm thick copper foil on one side of an insulating layer of a 50 μm thick liquid crystal polymer layer. This is derived from a single-sided copper-clad laminate LX _4. The liquid crystal polymer layer 407 adjacent to the liquid crystal polymer layer 404 and the wiring circuit layer 412 are derived from a liquid crystal polymer layer 404 having a thickness of 50 μm. the insulating layer single-sided copper-clad laminate to a copper foil having a thickness of 18μm on one side of (. hereinafter referred to as one-sided copper-clad laminate LX ₅ of the liquid crystal polymer melting point: 280 ° C.) from which the resin layer and its It is a wiring circuit layer formed by processing a copper foil. The wiring circuit layer 408 includes the wiring circuit layer 412 and the BVH 409 and the plated copper 413 that is the same as the plated through hole 410, and the wiring circuit layer 402 ′ includes the wiring circuit layer 414 and the plated copper 413.

Here, the thickness of the liquid crystal polymer of the single-sided copper-clad laminate LX ₄ and the single-sided copper-clad laminate LX ₅ is 50 μm, the wiring circuit layers 406 and 412 are 18 μm, the polyimide resin layer 403 is 25 μm, and the wiring circuit layer 402. 'The thickness of 408 is 18 μm. The through hole 410 has a hole diameter of 0.15 mm, the upper diameter of BVH 409 is 80 μm, the lower diameter is 75 μm, the thickness of the plated copper 413 is 8 μm, and the film thickness of the solder resist layer 411 is 20 μm. The roughness (Rz) of the interface 415 between the polyimide resin layer 403 and the liquid crystal polymer layer 404 was 4.7 μm and 4.6 μm as a result of cross-sectional observation. Also. The total thickness of the four-layer printed wiring board 401 was about 168 μm.

(Example 5)
A manufacturing method of the four-layer printed wiring board 501 having the same structure as the four-layer printed wiring board of Example 1 will be described in detail with reference to process cross-sectional views shown in FIGS.
A copper circuit 503 on both sides of a double-sided copper-clad laminate (Espanex S (SB12-25-12CE)) 502 having the polyimide resin layer shown in FIG. 7A as an insulating layer is patterned by a subtractive method, and a wiring circuit A 400 × 300 mm double-sided wiring board 505 on which the layer 504 was formed was produced (FIG. 7B). Next, a single-sided copper-clad laminate LX506 of the same size having a liquid crystal polymer layer as an insulating layer was prepared, the resin surfaces were opposed to each other, the double-sided wiring board 505 was sandwiched from both sides, and was set as it was in a vacuum press (FIG. 7). (C)). Next, the mold was clamped while evacuating the press hot platen 507 at 1.3 kPa, and the hot platen was heated to 260 ° C. and heated. Five minutes after the hot platen temperature reached 260 ° C., an adhesive pressure of 6 MPa was applied, and 10 minutes later, cooling of the hot platen 507 was started (FIG. 7D). After 20 minutes, the adhesive pressure was removed, the heating plate 507 was opened, and the laminate 508 was taken out (FIG. 7 (e)). A through hole 509 having a diameter of 0.15 mm was formed in the obtained laminate 508 by NC drilling (FIG. 7 (f)), and after a predetermined desmear treatment, a panel plating 510 having a thickness of 8 μm was formed (FIG. 7 (g) )). Then, the outermost layer 511 was etched and patterned by a tenting method, a wiring circuit layer 512 was formed, a solder resist layer 513 was formed, and a four-layer printed wiring board 501 was produced (FIG. 7H).
The yield loss due to powder falling in this process was 0%.

(Example 6)
Another method for manufacturing a four-layer printed wiring board 601 having the same structure as the four-layer printed wiring board of Example 5 will be described in detail with reference to process cross-sectional views shown in FIGS.
The copper foil 603 on both sides of the same double-sided copper-clad laminate 602 used in Example 5 was patterned by a subtractive method, and wound into a roll having a width of 300 mm and a length of 100 m on which the wiring circuit layer 604 was formed. A long double-sided wiring board 605 was produced (FIG. 8A). The double-sided wiring board 605 is sandwiched between the same-shaped single-sided copper-clad laminates LX606 with the resin surfaces facing from both sides (FIG. 8B), and is supplied between rolls 607 having a surface temperature of 260 ° C. It heated and pressurized at 20 kN / m (FIG.8 (c)). The obtained continuous laminate 608 is cut to 400 × 30 mm, and a through hole 609 having a diameter of 0.15 mm is formed by NC drilling (FIG. 8D). After predetermined desmear treatment, 8 μm thick panel plating is performed. 610 was formed (FIG. 8E). Then, the outermost layer 611 was etched and patterned by a tenting method, a wiring circuit layer 612 was formed, and a solder resist layer 613 was formed to produce a four-layer printed wiring board 601 (FIG. 8F).
The yield loss due to powder falling in this process was 0%.

(Example 7)
A method for manufacturing a four-layer printed wiring board 701 having the same structure as the four-layer printed wiring board of Example 2 will be described in detail with reference to process cross-sectional views shown in FIGS.
A double-sided copper-clad laminate (Espanex M product number: MB12-12-12FR) 702 (FIG. 9 (a)) having a 400 × 300 mm polyimide resin layer as an insulating layer is applied by a subtractive method. Pattern processing was performed to form a wiring circuit layer 704-2. Similarly, another double-sided copper-clad laminate 702 ′ was patterned (FIG. 9B). Next, the copper foil 706 on both sides of the double-sided copper clad laminate LY705 having the same size liquid crystal polymer layer as an insulating layer is removed by etching, and the exposed surface is potassium hydroxide (34% by mass) / ethylene glycol (22% by mass). A liquid crystal polymer layer 707 was prepared by immersion treatment in an alkali mixed aqueous solution of / ethylenediamine (11% by mass) at 60 ° C. for 60 seconds (FIG. 9C). The surface-treated liquid crystal polymer layer 707 is sandwiched between single-sided processed substrates 702 and 702 ′ facing the wiring circuit layers (704-2 and 704-1 ′) and set in a vacuum press as it is (FIG. 9 (d). )). Next, the mold was clamped while evacuating between the press hot plates 708 at 1.3 kPa, and the hot plate 708 was heated to 300 ° C. and heated. Five minutes after the hot platen temperature reached 300 ° C., an adhesive pressure of 4 MPa was applied, and 10 minutes later, cooling of the hot platen 708 was started (FIG. 9E). After 20 minutes, the adhesive pressure was removed, the hot platen 708 was opened, and the laminate 709 was taken out (FIG. 9 (f)). A through hole 710 having a diameter of 0.15 mm was formed in the obtained laminate 709 by NC drilling (FIG. 9G), and a panel plating 711 having a thickness of 8 μm was formed after predetermined desmear treatment (FIG. 9H )). Then, the outermost layer 712 was etched and patterned by a tenting method to form a wiring circuit layer 713, and further a solder resist layer 714 was formed to produce a four-layer printed wiring board 701 (FIG. 9 (i)).
The yield loss due to powder falling in this process was 0%.

(Example 8)
Another method for manufacturing a four-layer printed wiring board 801 having the same structure as the four-layer printed wiring board of Example 7 will be described in detail with reference to process cross-sectional views shown in FIGS.
Two sides of copper-clad laminate (Espanex M product number: MB12-12-12FR) 802, 802 ′ copper foils 803, 803 ′ each having a polyimide resin layer as an insulating layer are patterned by a subtractive method. Then, long double-sided wiring boards 805 and 805 ′ wound in a roll shape having a width of 30 mm and a length of 100 m on which the wiring circuit layers 804 and 804 ′ were formed were produced (FIG. 10A). Next, the copper foil on both sides of the double-sided copper clad laminate LY806 having the same shape liquid crystal polymer layer as the insulating layer is removed by etching, and the exposed surface is plasma-treated using a gas composed of argon, helium, oxygen, and nitrogen. A polymer layer 807 was produced (FIG. 10B). The liquid crystal polymer layer 807 is sandwiched between two wiring boards 805 and 805 ′ facing the wiring circuit layers 804 and 804 ′, and supplied between rolls 808 having a surface temperature of 260 ° C., and continuously at a linear pressure of 100 kN / m. It heated and pressurized (FIG.10 (c)). The obtained continuous laminate 809 is cut to 400 × 300 mm, and a through hole 810 having a diameter of 0.15 mm is formed by NC drilling (FIG. 10D). After predetermined desmear treatment, panel plating with a thickness of 8 μm is performed. 811 was formed (FIG. 10E). Then, the outermost layer 812 was etched and patterned by a tenting method, a wiring circuit layer 813 was formed, a solder resist layer 814 was formed, and a four-layer printed wiring board 801 was produced (FIG. 10F).
The yield loss due to powder falling in this process was 0%.

Example 9
A manufacturing method of the 8-layer printed wiring board 901 having the same structure as the 8-layer printed wiring board of Example 3 will be described in detail with reference to the process cross-sectional views shown in FIGS.
Double-sided copper-clad laminate (Espanex M product number: MB12-12-12FR) 902 (FIG. 11A) having a 400 × 300 mm polyimide resin layer as an insulating layer is used. Pattern processing was performed by a subtractive method to form wiring circuit layers 904-1 and 904-2. Similarly, another sheet was produced (FIG. 11 (b)). Next, the copper foil 906 on both sides of the double-sided copper clad laminate LY905 having the same size liquid crystal polymer layer as the insulating layer is removed by etching, and the exposed surface is potassium hydroxide (34% by mass) / ethylene glycol (22% by mass). / Liquid crystal polymer layer 907 which was immersed in an alkali mixed aqueous solution of ethylenediamine (11% by mass) at 80 ° C. for 30 seconds was produced (FIG. 11C). The surface-treated liquid crystal polymer layer 907 was sandwiched between the double-sided copper-clad laminates 902 and 902 ′ and set in a vacuum press as it was (FIG. 11 (d)). Next, the mold was clamped while evacuating between the press hot plates 908 at 1.3 kPa, and the hot plate 908 was heated to 280 ° C. and heated. Five minutes after the hot platen temperature reached 280 ° C., an adhesive pressure of 5 MPa was applied, and 10 minutes later, cooling of the hot platen 908 was started (FIG. 11 (e)). After 20 minutes, the adhesive pressure is removed, the heating platen 908 is opened, the laminate 909 is taken out, and the resin surface of the liquid crystal polymer is formed on both sides of the obtained laminate 909 with a gas composed of argon, helium, oxygen, and nitrogen. Was laminated with the resin surfaces 911 and 911 ′ of the single-sided copper-clad laminate LX ₂ 910 and 910 ′ facing each other (FIG. 11 (f)) and vacuum-pressed under the above conditions to produce a laminate 912. (FIG. 11 (g)). The copper foil at a predetermined position of the laminated body 912 was etched 913 to φ100 μm (FIG. 11 (h)), and then blind via holes 914 were formed with a carbonic acid laser (FIG. 11 (i)). After the desmear treatment, a plating layer 915 electrically connected to the wiring circuit layer 904-2 ′ was formed (FIG. 11 (j)), and a wiring circuit layer 916 was formed by a subtractive method (FIG. 11 (k)). The steps from FIG. 11 (f) to (i) are performed again, and a through hole 918 having a diameter of 0.15 mm is formed in the obtained laminate 917 by NC drilling (FIG. 11 (l)). After the desmear treatment, panel plating 919 having a thickness of 8 μm was formed (FIG. 11 (m)). However, the single-sided copper-clad laminate newly stacked in FIG. 11 (l), was used a single-sided copper-clad laminate LX _3. Then, the outermost layer 920 was etched and patterned by a tenting method, a wiring circuit layer 921 was formed, and a solder resist layer 922 was formed to produce an eight-layer printed wiring board 901 (FIG. 11 (n)).
The yield loss due to powder falling in this process was 0%.

(Example 10)
Another manufacturing method of the 8-layer printed wiring board 1001 having the same structure as the 8-layer printed wiring board of Example 9 will be described in detail with reference to process cross-sectional views shown in FIGS.
Two double-sided copper-clad laminates (Espanex M product number: MB12-12-12FR) 1002 and 1002 ′ each having a polyimide resin layer as an insulating layer 1003-1, 1003-2, and 1003-1 ′ , 1003-2 ′ were patterned by a subtractive method, and wound into a roll having a width of 300 mm × a length of 100 m in which wiring circuit layers 1004-1, 1004-2, 1004-1 ′, and 1004-2 ′ were formed. Long double-sided wiring boards 1005 and 1005 ′ were produced (FIG. 12A). Next, the copper foil on both sides of the double-sided copper-clad laminate LY1006 having the same shape liquid crystal polymer layer as an insulating layer is removed by etching, and the exposed surface is plasma-treated using a gas comprising argon, helium, oxygen, and nitrogen. A polymer layer 1007 was produced (FIG. 12B). The liquid crystal polymer layer 1007 is sandwiched between two double-sided wiring boards 1005 and 1005 ′, supplied between rolls 1008 having a surface temperature of 240 ° C., and continuously heated and pressurized at a linear pressure of 100 kN / m (FIG. 12 (c )). On both surfaces of the obtained continuous laminate 1009, a single-sided copper-clad with a liquid crystal polymer layer having a width of 300 mm × length of 100 m obtained by plasma treatment of the resin surface using a gas composed of argon, helium, oxygen, and nitrogen. The resin surfaces 1011 and 1011 ′ of the laminates LX ₂ 1010 and 1010 ′ were stacked to face each other and continuously heated and pressurized under the above conditions to produce a continuous laminate 1012 (FIG. 12D). Next, an etching process 1014 of φ100 μm was performed at predetermined positions on the outermost copper foils 1013 and 1013 ′ of the continuous laminate 1012, and then blind via holes 1015 were processed with a carbonic acid laser (FIG. 12E). After the desmear treatment, a plating layer 1016 electrically connected to the wiring circuit layer 1004-2 ′ was formed (FIG. 12 (f)), and a wiring circuit layer 1017 was formed by a subtractive method (FIG. 12 (g)). The steps of FIGS. 12D to 12E are performed again, and a through hole 1019 having a diameter of 0.15 mm is formed in the obtained continuous laminate 1018 by NC drilling (FIG. 12H), and a predetermined desmear is formed. After the treatment, a panel plating 1020 having a thickness of 8 μm was formed (FIG. 12 (i)). However, the single-sided copper-clad laminate newly stacked in FIG. 11 (h), using the one-sided copper-clad laminate LX _3. Then, after cutting to 400 mm × 300 mm, the outermost layers 1021 and 1021 ′ are etched and patterned by a tenting method to form a wiring circuit layer 1022 and a solder resist layer 1023 to form an eight-layer printed wiring board 1001. (FIG. 12 (j)).
The yield loss due to powder falling in this process was 0%.

(Comparative Example 1)
In Example 5, a glass epoxy double-sided copper-clad laminate (MCL-E-679 manufactured by Hitachi Chemical Co., Ltd .; copper foil thickness 12 μm, insulating base material thickness 60 μm) was used instead of Espanex S. A four-layer substrate having a total thickness of 190 μm was produced. The yield loss due to powder falling was 4.5%.

(Comparative Example 2)
In Example 6, a copper foil with resin (R0880 made by Matsushita Electric Works; copper foil thickness 12 μm, resin thickness 50 μm) was used instead of the single-sided copper clad laminate LX, and the surface temperature of the laminate roll was changed to 180 ° C. Carried out. However, since the resin-coated copper foil broke during lamination, a four-layer printed wiring board could not be produced.

It is sectional drawing which shows an example of the basic structure of the multilayer printed wiring board of this invention. It is sectional drawing which shows an example different from FIG. 1 of the basic structure of the multilayer printed wiring board of this invention. 1 is a cross-sectional view showing the structure of a multilayer printed wiring board of Example 1. FIG. It is sectional drawing which shows the structure of the multilayer printed wiring board of Example 2. FIG. It is sectional drawing which shows the structure of the multilayer printed wiring board of Example 3. FIG. It is sectional drawing which shows the structure of the multilayer printed wiring board of Example 4. It is a figure for demonstrating the manufacturing process of the multilayer printed wiring board of Example 5. FIG. It is a figure for demonstrating the manufacturing process of the multilayer printed wiring board of Example 6. FIG. It is a figure for demonstrating the manufacturing process of the multilayer printed wiring board of Example 7. FIG. It is a figure for demonstrating the manufacturing process of the multilayer printed wiring board of Example 8. FIG. It is a figure for demonstrating the manufacturing process of the multilayer printed wiring board of Example 9. FIG. It is a figure for demonstrating the manufacturing process of the multilayer printed wiring board of Example 10. FIG.

Explanation of symbols

10, 101, 201, 301, 401, 501, 601, 701, 801, 901, 1001 Multilayer printed wiring board 12, 12a, 102, 106, 109, 202-1, 202-2, 208, 208 ′, 305, 305 ′, 308, 308 ′, 311, 311 ′, 313, 313 ′, 402, 402 ′, 406, 408, 412, 414, 504, 512, 604, 612, 713, 804, 804 ′, 813, 916, 921, 1004-1, 1004-2, 1004-2 ′, 1017, 1022 Wiring circuit layers 14a, 14b, 16c Insulating layers 16, 16a Laminated structural units 103, 203, 203 ′, 403 Polyimide resin layers 104, 204, 303 , 303 ′, 306, 306 ′, 317, 317 ′, 404, 407, 707, 807, 907, 10 7 Liquid crystal polymer layer 105, 205, 302, 405 Basic structure 107, 206, 309, 410 Plating through hole 108, 207, 310, 513, 613, 714, 814, 922, 1023 Solder resist layer 503, 603, 703-2 , 706, 803, 803, 803 ′, 903-1, 903-2, 904-1, 904-2, 906, 1003-1, 1013, 1013 ′ Copper foil 110, 209, 312, 314 Plated copper 111, 315 Through-hole land 112, 210, 316, 411, 415 Interface 304 ′ IVH
307, 307 ', 409 BVH
413 Plating 502, 602, 705, 806, 905, 1006 Double-sided copper-clad laminate 505, 605, 805, 805 ′, 1005, 1005 ′ Double-sided wiring board 506, 606, 910, 910 ′, 1010, 1010 ′ Single-sided copper-clad Laminated plate 507, 708, 908 Press hot platen 508, 709, 909, 912, 917 Laminated body 509, 609, 710, 810, 918, 1019 Through hole 510, 610, 711, 811, 919, 1020 Panel plating 511, 611 , 712, 812, 920, 1021 Outermost layer 607 Roll 608, 809, 1009, 1012, 1018 Continuous laminate 702, 702 ′, 802, 902, 902 ′, 1002 Espanex M
704-1 ′, 704-2, 904-2 ′ Wiring circuit layer 808, 1008 Roll 911, 911 ′, 1011, 1011 ′ Resin surface 913, 1014 Etching portion 914, 1015 Blind via hole 915, 1016 Plating layer

Claims (5)

In the method for producing a multilayer printed wiring board in which wiring circuit layers and insulating layers are alternately laminated,
On both sides of the polyimide resin layer to form a wiring circuit layer and double-sided circuit board, on both sides of its a double-sided wiring board as a core substrate for a multilayer printed wiring board characterized by having a step of forming a liquid crystal polymer layer Manufacturing method . The method for producing a multilayer printed wiring board according to claim 1, wherein a liquid crystal polymer layer is further formed on a side opposite to the side adjacent to the core substrate of the liquid crystal polymer layer via a wiring circuit layer. The method for producing a multilayer printed wiring board according to claim 1 or 2, wherein a roughness of a boundary surface between the polyimide resin layer and the liquid crystal polymer layer is 4 to 6 µm. The method for producing a multilayer printed wiring board according to claim 1 or 2, wherein the roughness of the interface between the polyimide resin layer and the liquid crystal polymer layer is less than 4 µm. Method for manufacturing a multilayer printed wiring board according to any one of claims 1 to 4, characterized in that the stacking surface of the liquid crystal polymer layer is formed by previously surface-treated.

Images