JP2012060031A - Manufacturing method for multi-layer wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method for a multi-layer wiring board of high productivity which can manufacture metal wiring of high accuracy and high adhesion and can manufacture a multi-layer wiring board of excellent veer connection reliability for high yield.SOLUTION: A manufacturing method for a multi-layer wiring board comprises: (A) a process for forming an insulation layer on the surface of a wiring board comprising metal wiring; (B) a process for forming a veer hole; (C) a process for performing a desmear process; (D) a process for obtaining a laminated body by laminating on the insulation layer a laminated film for resin layer formation comprising a temporary support body, a function group which forms interaction with a plating catalyst or a precursor on the temporary support body, and a resin layer including a polymer containing a polymerizable group, so that the resin layer and the insulation layer which has the desmear process done contact each other; (E) a process for peeling the temporary support body from the laminated body; (F) a process for attaching the plating catalyst and the precursor on the wall of the veer hole and the resin layer to perform plating.

Description

  The present invention relates to a method for manufacturing a multilayer wiring board.

  In recent years, along with demands for higher functionality of electronic devices, electronic components have been densely integrated, and further, high-density mounting has been progressing. Is becoming more and more dense. Various methods such as realization of high-definition and stable wiring and adoption of a build-up multilayer wiring board have been studied as measures for increasing the density of printed wiring boards and the like. Furthermore, a product is also available that is formed by laminating wiring layers by a build-up method in which electrically insulating layers are connected by fine vias.

To date, manufacturing methods relating to various multilayer wiring boards have been proposed (Patent Documents 1 to 4).
In particular, Patent Document 4 proposes a method for manufacturing a multilayer wiring board in which interlayer connection by vias is made and a multilayer wiring board having fine wiring can be manufactured by a simple method.
Specifically, in this method, first, an insulating layer is formed on the surface of a substrate having a portion that can conduct electricity, and then the insulating layer is partially removed by a laser or a drill to form a via hole. . Thereafter, a desmear process is performed on the surface on which the via hole is formed, and the residue of the insulating layer at the bottom of the via hole is removed. Furthermore, a resin layer is formed on the surface on which the desmear treatment has been performed using a liquid composition containing a resin having a predetermined functional group. Thereafter, the resin layer formed at the bottom of the via hole is removed by applying a treatment liquid, and a plating catalyst is applied to the remaining resin layer, followed by plating.

Japanese Patent Laid-Open No. 8-46327 Japanese Patent Laid-Open No. 11-274731 JP 2003-224365 A JP 2010-157590 A

In the method disclosed in Patent Document 4, as described above, a resin layer is formed using a liquid composition on an insulating layer in which a via hole is formed. At that time, since the liquid composition penetrates into the via hole, it is necessary to remove unnecessary resin accumulated in the via hole.
However, it is very difficult on an industrial level to control the adhesion state of the resin on the wall surface of the via hole while removing the resin on the bottom surface of the via hole, and as a result, via plating defects and via shape variations tend to be caused. In fact, when the present inventors manufactured a multilayer wiring board using the method described in Patent Document 4, initial conduction failure is likely to occur, and the required yield level has not been reached recently. Further improvements were needed.

  In view of the above circumstances, the present invention can produce a metal wiring with high definition and excellent adhesion, and can produce a multilayer wiring board with excellent via connection reliability with high yield. It aims at providing the manufacturing method of the outstanding multilayer wiring board.

As a result of intensive studies in view of the above problems, the present inventor has found that the above object can be achieved by the following means.

(1) (A) a step of forming an insulating layer on the surface of a wiring board provided with metal wiring; (B) a step of forming a via hole so as to penetrate the insulating layer and reach the metal wiring;
(C) a step of performing a desmear treatment after the step (B);
(D) After the step (C), a temporary support, a functional group that forms an interaction with the plating catalyst or its precursor on the temporary support, and a resin layer containing a polymer containing a polymerizable group; Laminating a laminated film for forming a resin layer on the insulating layer so that the resin layer and the insulating layer subjected to desmear treatment are in contact with each other, and obtaining a laminated body;
(E) After the step (D), a step of peeling the temporary support from the laminate,
(F) After the step (E), a plating catalyst or a precursor thereof is applied to the wall surface of the via hole and the resin layer, and plating is performed.
In the step (D), the temperature T of the resin layer when laminating is not less than the glass transition temperature of the resin layer and not more than the glass transition temperature + 60 ° C., and the Young's modulus E (T) of the resin layer at the temperature T Is 0.16 × 10 ^{6 to} 100 × 10 ⁶ Pa, and the elongation at break of the resin layer is 100% or less,
When laminating the laminated film for resin layer formation, the pressure P applied to the laminated film for resin layer formation and Log (E (T)) are represented by the following formulas (I) to (I) shown in FIG. A manufacturing method of a multilayer wiring board existing in a range surrounded by a straight line represented by IV).
Formula (I) Log (E (T)) = 5.2
Formula (II) Log (E (T)) = 8
Formula (III) P = 0.3 × 10 ⁶ (Log (E (T)) − 1.4 × 10 ⁶
Formula (IV) P = 0.06 × 10 ⁶ (Log (E (T)) − 0.3 × 10 ⁶

(2) In the said process (E), the temperature of the said resin layer is 0-40 degreeC,
Interfacial peel strength σ (A1) per unit area between the resin layer and the insulating layer, interfacial peel strength σ (B1) per unit area between the resin layer and the temporary support, and fracture of the resin layer The method for manufacturing a multilayer wiring board according to (1), wherein the stress σ (C1) satisfies the following relationship.
σ (A1)> σ (B1)> σ (C1)
(3) The manufacturing method of the multilayer wiring board as described in (1) or (2) whose thickness of the said resin layer is 0.05-3.0 micrometers.
(4) The multilayer wiring board according to any one of (1) to (3), further including a step of applying energy to the resin layer between the step (E) and the step (F). Production method.

(5) The method for manufacturing a multilayer wiring board according to (1), wherein the following steps (G) to (J) are performed in this order instead of the steps (D) and (E).
(G) After the step (C), the adhesion auxiliary layer forming laminated film provided with the temporary support and the adhesion auxiliary layer on the temporary support, and the adhesion auxiliary layer and the desmear treatment on the insulating layer. Laminating the applied insulating layer so as to be in contact with each other and obtaining a laminated body (H) After the step (G), the step of peeling the temporary support from the laminated body (I) After the step (H) A laminated film for forming a resin layer, comprising: a temporary support; and a resin layer containing a polymer containing a polymerizable group and a functional group that forms an interaction with the plating catalyst or a precursor thereof on the temporary support. The step (J) of obtaining a laminate by laminating the resin layer and the adhesion auxiliary layer in contact with the adhesion auxiliary layer (J) After the step (I), peeling the temporary support from the laminate. Process In addition, the said process (G) and the said process ( In I), the temperature T of the adhesion assisting layer and the resin layer when laminating is not less than the glass transition temperature of each of the adhesion assisting layer and the resin layer and not more than the glass transition temperature + 60 ° C., and the temperature T The Young's modulus E (T) of the adhesion auxiliary layer and the resin layer is 0.16 × 10 ^{6 to} 100 × 10 ⁶ Pa, and the elongation at break of the adhesion auxiliary layer and the resin layer is 100% or less,
When laminating the laminated film for forming an adhesion auxiliary layer and the laminated film for forming a resin layer, a pressure P applied to the laminated film for forming an adhesion auxiliary layer and the laminated film for forming a resin layer, and Log (E (T )) Exists in a range surrounded by a straight line represented by the following formulas (I) to (IV) shown in FIG.
Formula (I) Log (E (T)) = 5.2
Formula (II) Log (E (T)) = 8
Formula (III) P = 0.3 × 10 ⁶ (Log (E (T)) − 1.4 × 10 ⁶
Formula (IV) P = 0.06 × 10 ⁶ (Log (E (T)) − 0.3 × 10 ⁶

(6) The method for producing a multilayer wiring board according to (5), further comprising a step of applying energy to the resin layer between the step (J) and the step (F).
(7) The method for producing a multilayer wiring board according to (5) or (6), wherein the adhesion auxiliary layer contains a polymerization initiator.
(8) The method for producing a multilayer wiring board according to any one of (1) to (7), wherein the plating catalyst or a precursor thereof is a compound containing Pd, Ag, or Cu.
(9) The method for producing a multilayer wiring board according to any one of (1) to (8), wherein the functional group that forms an interaction with the plating catalyst or its precursor is a cyano group or a carboxylic acid group.
(10) A multilayer wiring board obtained by the method for manufacturing a multilayer wiring board according to any one of (1) to (9).

  According to the present invention, it is possible to manufacture a metal wiring with high definition and excellent adhesion, and it is possible to manufacture a multilayer wiring board with excellent connection reliability of vias with a high yield. A method for manufacturing a substrate can be provided.

(A)-(E) are typical sectional drawing from the board | substrate which shows each manufacturing process in the manufacturing method of the multilayer wiring board of this invention in order to a multilayer wiring board, respectively. (A)-(E) are typical sectional drawings from the board | substrate which shows each manufacturing process in the other embodiment of the manufacturing method of the multilayer wiring board of this invention in order from a board | substrate to a multilayer wiring board, respectively. It is a figure showing the range prescribed | regulated by the pressure P at the time of lamination, and Log (E (T)). Cut-out removal is an (A) surface SEM photograph and (B) cross-sectional SEM photograph of an OK product (via holes remain). Part of the layer remains, and the cut-out removal is an NG product (A) surface SEM photograph and (B) cross-sectional SEM photograph. The via hole is closed by the layer, and the cut-out removal is an NG product (A) surface SEM photograph and (B) cross-sectional SEM photograph. It is the figure showing the relationship between the Young's modulus obtained in the Example, the pressure P at the time of lamination, and via-hole formation property. (A) is typical sectional drawing showing the via chain obtained in Examples 1-3 and Comparative Example 1, (B) is typical sectional drawing showing the via chain obtained in Example 4. is there. 3 is a cross-sectional SEM photograph of a via chain obtained in Comparative Example 1.

Below, the manufacturing method of the multilayer wiring board of this invention is explained in full detail.
One of the features of the production method of the present invention is that a laminated film for forming a resin layer including a temporary support and a resin layer is disposed on an insulating layer in which via holes are formed, and then the temporary support is peeled off. There is. In this procedure, when the temporary support is peeled from the laminated body, stress concentration occurs at the outer peripheral position of the via hole, so that the resin layer is cut along the outer peripheral shape of the via hole. As a result, the resin layer on the temporary support that is not in intimate contact with the insulating layer remains on the temporary support as it is, and is removed from the laminate together with the temporary support peeling, so that the resin layer is substantially only on the insulating layer. Can be formed. When the substrate thus obtained is used, a multilayer wiring substrate having excellent via connection reliability can be manufactured with high productivity. In addition, this method does not use a liquid composition containing an organic solvent, so that it can be said to be an excellent method from the environmental and process aspects.

The manufacturing method includes the following six steps.
(A) A step of forming an insulating layer on the surface of a wiring board having metal wiring (B) A step of forming a via hole so as to penetrate the insulating layer and reach the metal wiring (C) After the step (B), Step (D) of performing desmear treatment After the step (C), a polymer containing a temporary support, a functional group that interacts with the plating catalyst or its precursor on the temporary support, and a polymerizable group Step (E) of obtaining a laminate by laminating a laminated film for forming a resin layer comprising a resin layer containing the resin layer on the insulating layer so that the resin layer and the insulating layer subjected to desmear treatment are in contact with each other (D) ) Later, the step of peeling the temporary support from the laminate (F) After the step (E), a step of applying a plating catalyst or its precursor to the wall surface of the via hole and the resin layer, and performing plating. Each process is explained in turn. Light up.

<Process (A): Insulating layer forming process>
In the step (A), an insulating layer is formed on the surface of a wiring board provided with metal wiring.
More specifically, as shown in FIG. 1A, in this step, the wiring substrate 10 in which the metal wiring 14 is formed on the substrate 12 and the insulating layer 16 provided on the wiring substrate 10 are provided. A laminated body is provided.
The wiring board 10 and the insulating layer 16 will be described in detail below.

<Wiring board 10>
The wiring board 10 used in the present invention may be any board having the metal wiring 14 on one side or both sides of the board 12, for example. Further, as shown in FIG. 1, the metal wiring 14 may be formed in a pattern with respect to the surface of the substrate, or may be formed on the entire surface. Typically, those formed by a subtractive method using an etching process and those formed by a semi-additive method using electrolytic plating may be used, and those formed by any method may be used.
More specifically, the wiring board 10 may be a double-sided or single-sided copper-clad laminate (CCL), or a copper-clad laminate made of a copper film in a pattern, which is a flexible substrate. It may be a rigid substrate.

More specifically, in a rigid substrate, as a paper base copper-clad laminate, paper / phenolic resin copper-clad laminate (FR-1, FR-2, XXXPc, XPc), paper / epoxy resin copper-clad laminate (FR-3), paper / polyester copper-clad laminate, and glass substrate / copper-clad laminate, glass cloth / epoxy resin copper-clad laminate (FR-4, G10), heat-resistant glass cloth / epoxy resin copper Stretch laminate (FR-5, G11), glass cloth / polyimide resin copper clad laminate (GPY), glass cloth / fluorine resin copper clad laminate, multilayer material (prepreg / FR-4, FR- which is thin) 5, GPY), multilayer copper clad laminates with inner circuit (FR-4, FR-5, GPY), etc., and as composite copper clad laminates, epoxy, composites, paper, glass cloth, epoxy resin Copper-clad laminate (CEM-1), glass nonwoven fabric / glass cloth / epoxy resin copper clad laminate (CEM-2), polyester composite, glass nonwoven fabric / glass cloth / polyester resin copper clad laminate (FR-6) Glass mat, glass cloth, polyester resin copper clad laminate, and the like.
Moreover, in a flexible substrate, copper-clad boards, such as polyester base, polyimide base, glass epoxy base, polysulfone base, polyetherimide base, polyether ketone base, etc. are mentioned.
Furthermore, the copper clad laminated board which used the inorganic material as the base material is mentioned, The copper clad board etc. which used alumina, aluminum nitride, silicon carbide, a low-temperature baking ceramic etc. are mentioned as a base material.

Examples of the material constituting the substrate 12 in the wiring substrate 10 include a glass epoxy substrate, a BT resin, an alumina substrate, a polyimide film, a polyamide film, a liquid crystal film, and an aramid. Of these, a glass epoxy substrate and a BT resin are preferable from the viewpoint of multilayering and productivity of the substrate.
Examples of the material constituting the metal wiring 14 include copper, silver, tin, palladium, gold, nickel, chromium, tungsten, indium, zinc, or gallium.

<Insulating layer 16>
The insulating layer 16 is a layer provided to ensure insulation reliability in the multilayer wiring board, and the formation method thereof is not particularly limited. More specifically, an insulating resin composition containing an insulating resin is applied onto the wiring substrate 10 to form an insulating layer 16 (application method), or an insulating layer 16 containing an insulating resin is formed. The method of laminating on the wiring board 10 etc. is mentioned.
The thickness of the insulating layer 16 is appropriately selected according to the purpose of use of the multilayer wiring board, but is preferably 10 to 150 μm, and more preferably 20 to 100 μm.
In addition, the “insulating resin” in the present invention means a resin having an insulating property that can be used for a known insulating film or insulating layer, and is not a perfect insulator. In addition, any resin having insulating properties according to the purpose can be applied to the present invention.

Specific examples of the insulating resin may be, for example, a thermosetting resin, a thermoplastic resin, or a mixture thereof. Examples of the thermosetting resin include an epoxy resin, a phenol resin, a polyimide resin, a polyester resin, and a bismaleimide. Examples thereof include resins, polyolefin resins, isocyanate resins and the like.
Examples of the thermoplastic resin include phenoxy resin, polyether sulfone, polysulfone, polyphenylene sulfone, polyphenylene sulfide, polyphenyl ether, polyether imide, and the like.

  The insulating resin composition used for forming the insulating layer 16 contains a compound having a polymerizable double bond, specifically an acrylate or methacrylate compound, in order to promote crosslinking. In particular, polyfunctional ones are preferred.

Furthermore, the insulating resin composition may be provided with a filler (for example, silica, alumina, clay, talc, etc.), a colorant, a flame retardant, an adhesion imparting agent, a silane coupling agent, and an antioxidant as necessary. In addition, one or more of various additives such as an ultraviolet absorber may be added.
When these materials are added to the insulating resin composition, it is preferable to add them in the range of 1 to 200% by mass, and more preferably in the range of 10 to 80% by mass with respect to the resin. Is done.

<Process (B): Via hole formation process>
In the step (B), a via hole is formed in the insulating layer formed in the step (A) so as to penetrate the insulating layer and reach the metal wiring.
More specifically, as shown in FIG. 1B, in this step, a part of the insulating layer 16 is removed and a via hole 18 is formed. As shown in FIG. 1B, the via hole 18 penetrates the insulating layer 16 and reaches the vicinity of the surface of the metal wiring 14. The via hole 18 is provided to electrically connect a metal layer 28 (described later) formed on the insulating layer and the metal wiring 14.

The method for forming the via hole 18 is not particularly limited, and a known method is employed. Of these, laser processing or drilling is preferred from the viewpoint of easy control of the diameter of the via hole to be formed and alignment.
The laser used for laser processing is not particularly limited as long as the insulating layer 16 can be removed and the via hole 18 having a desired diameter can be formed. Among these, an excimer laser, a carbon dioxide laser (CO ₂ laser), a UV-YAG laser, or the like is used from the viewpoint of excellent workability, that is, efficient ablation and excellent productivity. Of these, a carbon dioxide laser and a UV-YAG laser are preferable in terms of cost merit.

  The drilling is not particularly limited as long as the insulating layer 16 can be removed and the via hole 18 having a desired diameter can be formed, but the spin drill method is generally used from the viewpoint of productivity and small diameter via workability. Used for.

  The diameter of the via hole 18 formed in this step is appropriately selected according to the purpose of use, but the top diameter (φ) is 10 in terms of downsizing the substrate and increasing the density of the wiring. The bottom diameter (φ) is preferably 10 to 150 μm, the top diameter (φ) is 10 to 60 μm, and the bottom diameter (φ) is more preferably 10 to 60 μm.

<Process (C): Desmear treatment process>
In the step (C), a desmear process for removing smear (residue) remaining in the via hole 18 formed in the step (B) is performed.
When the insulating layer 16 is partially removed by laser processing, drilling, or the like, the molten material when the resin melts or decomposes, the decomposed material adheres to the side surface or bottom of the via hole 18, and the bottom of the via hole 18 In some cases, the insulating layer 16 may remain at the bottom of the via hole by adjusting the laser processing so as not to directly affect the metal wiring 14 existing in the hole. In this step, such a residue is removed.

The desmear treatment method is not particularly limited, and a known method is adopted. However, the desmear treatment is performed by a method of roughening a wall surface and a bottom surface of the hole portion of the via hole 18 by a dry method and / or a wet method.
Examples of the dry roughening method include mechanical polishing such as buffing and sandblasting, plasma etching, and the like.
On the other hand, wet roughening methods include chemical methods such as a method using an oxidizing agent such as permanganate, dichromate, ozone, hydrogen peroxide / sulfuric acid, nitric acid, or a method using a strong base or a resin swelling solvent. Examples include chemical treatment. From the simplicity of the process, chemical treatment using permanganate or the like is preferable.

  As a specific method of the desmear treatment, for example, a commercial product MLB211 (manufactured by Rohm and Haas Electronic Materials Co., Ltd.) is placed in a swelling bath containing 20% by volume and Kewposit Z10% by volume, and the object is placed at 60 to 85 ° C. And then immersed in an etching bath containing 10% by volume of MLB213A (made by Rohm and Haas Electronic Materials Co., Ltd.) and 15% by volume of MLB213B (made by Rohm and Haas Electronic Materials Co., Ltd.) at 55 to 85 ° C. Examples of the known method include immersion treatment for 2 to 15 minutes and immersion in a neutralization bath containing 20% by volume of MLB 216-2 (Rohm and Haas Electronic Materials Co., Ltd.) at 35 to 55 ° C. for 2 to 10 minutes. .

  As another method of desmear treatment, there is a treatment having an etching step at 80 ° C. for 10 minutes using a sodium permanganate etching solution, a neutralization step at 40 ° C. for 5 minutes using a sulfuric acid-based neutralizing solution, and the like. Can be mentioned.

By performing the desmear process as described above, the residue of the insulating layer 16 on the wall surface and bottom of the via hole 18 can be removed.
Since the desmear process is performed on the entire surface of the substrate, the residue of the insulating layer 16 at the bottom of the via hole 18 is removed, and the upper portion of the insulating layer 16 and the inside of the via hole 18 are roughened.

<Process (D): Laminate formation process>
In the step (D), a resin layer comprising a temporary support, and a resin layer containing a polymer containing a polymerizable group and a functional group that forms an interaction with the plating catalyst or its precursor on the temporary support. The forming laminated film is laminated on the insulating layer so that the resin layer and the insulating layer subjected to the desmear treatment are in contact with each other to obtain a laminated body.
More specifically, as shown in FIG. 1C, in this step, a resin layer including a temporary support 22 and a resin layer 20 provided on the temporary support 22 on the insulating layer 16. The forming laminated film 24 is laminated so that the resin layer 20 is in contact with the insulating layer 16 to obtain a laminated body 26.

The method of laminating the resin layer forming laminated film 24 on the insulating layer 16 so that the resin layer 20 is in contact with the insulating layer 16 is not particularly limited, and may be a batch type or a continuous type in a roll. .
The temperature T of the resin layer 20 when laminating the laminated film 24 for resin layer formation is such that the adhesion between the resin layer 20 and the insulating layer 16 is excellent, and the breaking strength of the resin layer 20 is reduced. It is not less than the glass transition temperature of the resin layer and not more than (glass transition temperature + 60 ° C.). Especially, the range of the temperature T is preferably the glass transition temperature of the resin layer + 10 ° C. to the glass transition temperature + 40 ° C., and more preferably the glass transition temperature of the resin layer + 20 ° C. to the glass transition temperature + 30 ° C. If the temperature T is lower than the glass transition temperature, the adhesion between the resin layer 20 and the insulating layer 16 is impaired. If the temperature T exceeds (glass transition temperature + 60 ° C.), the resin layer 20 enters the via hole 18, and the via hole 18. Will be buried.
In addition, although the glass transition temperature of a resin layer changes with structures of the polymer mentioned later, it is preferable that it is 0-140 degreeC, and it is more preferable that it is 20-120 degreeC at the point which the effect of this invention is more excellent.

The Young's modulus of the resin layer 20 is 0.16 × 10 ^{6 to} 100 × 10 ⁶ Pa when the temperature T is in the above range because the adhesion between the resin layer 20 and the insulating layer 16 is excellent. Among them, in that the yield of the obtained multilayer wiring board is more excellent, more preferably preferably from ^{0.5 × 10 6 ~10 × 10 6} Pa, 1 × 10 6 ~5 × 10 6 Pa . If the Young's modulus is less than 0.16 × 10 ⁶ Pa, the resin layer 20 enters the via hole 18 and fills the via hole 18. If it exceeds 100 × 10 ⁶ Pa, the resin layer 20 and the insulating layer 16 The adhesion of is impaired.

The elongation at break of the resin layer 20 is 100% or less, and is preferably 1 to 100% from the viewpoint of better adhesion between the resin layer 20 and the insulating layer 16. Especially, it is preferable that it is 3 to 100% in the point which the yield of the multilayer wiring board obtained is more excellent, and it is more preferable that it is 5 to 50%. If the elongation at break is more than 100%, it is difficult to cut out the resin layer 20 during lamination, and the resin layer 20 enters the via hole, and the resin pool is likely to occur. Further, even if the removal of the cutout can be achieved at the time of peeling the temporary support, the cutout shape tends to be distorted because the plastic deformation amount of the resin layer 20 is large. Specifically, the resin layer 20 is formed so as to block a part of the upper end of the via hole. As a result, defects are often caused in the subsequent desmear process or filling plating process.
The elongation at break is a value measured at 100 ° C.

The pressure (pressing pressure, pressing) P applied to the laminated film 24 for resin layer formation in order to assist the adhesion between the resin layer 20 and the insulating layer 16 at the time of laminating is the relationship between the formulas (III) and (IV) described later. From the point that the adhesiveness between the resin layer 20 and the insulating layer 16 is more excellent, it is preferably 0.1 × 10 ⁵ to 1 × 10 ⁶ Pa, preferably 0.2 × 10 ^{5 to} 0 More preferably, it is 8 × 10 ⁶ .

In step (D), the temperature T of the resin layer 20 at the time of lamination, the Young's modulus E (T) of the resin layer 20 at the temperature T, and the elongation at break of the resin layer 20 are within the above ranges. The pressure (pressing) P applied to the film and Log (E (T)) are present in a range surrounded by straight lines represented by the following formulas (I) to (IV) shown in FIG.
Formula (I) Log (E (T)) = 5.2
Formula (II) Log (E (T)) = 8
Formula (III) P = 0.3 × 10 ⁶ (Log (E (T)) − 1.4 × 10 ⁶
Formula (IV) P = 0.06 × 10 ⁶ (Log (E (T)) − 0.3 × 10 ⁶
If it is the range enclosed by the straight line represented by the said Formula, both the lamination of a resin layer and formation of a via hole (cutout of a resin layer) will become favorable. In addition, the pressure P means the pressure applied to the wiring board 10 side from the temporary support body 22 surface in FIG.
If it is out of the above range, the resin layer on the via is not cut out or laminated.
In addition, the range whose Log (E (T)) is 6-7 is mentioned as a suitable range at the point which the connection reliability between wiring is more excellent.

  The above formula shows the relationship between the Young's modulus of the resin layer 20 and the pressure applied to the laminated film 24 for resin layer formation. From the relationship of the above formula, when the Young's modulus of the resin layer 20 is in a predetermined range, the applied pressure P is in the predetermined range, whereby the via hole formability is excellent. If the applied pressure P is too high, there will be an inconvenience that the via hole 18 of the resin layer 20 is sunk during the lamination and the via hole 18 is filled. If the applied pressure is too small, a lamination failure occurs and voids are easily generated, and it is difficult to apply an appropriate stress to the via part cutout.

(Laminated film for resin layer formation)
Next, the temporary support 22 and the resin layer 20 constituting the laminated film 24 for resin layer formation used in this step will be described in detail.

(Temporary support 22)
The temporary support 22 used in the laminated film 24 for forming a resin layer of the present invention is not particularly limited as long as it is a substrate that supports the resin layer 20 formed on the surface. For example, polyolefins such as polyethylene, polypropylene, and polyvinyl chloride, polyesters such as polyethylene terephthalate, polyamide, polyimide, polycarbonate and other resin sheets, and release paper made by laminating resin sheets are also used. be able to.
Among them, the material of the temporary support 22 is polyethylene, polypropylene, polyester, polyimide, polyvinyl chloride, polyvinylidene chloride, polytetrafluoroethylene, etc. from the viewpoint of smoothness, flexibility, heat resistance, releasability, and the like. Is preferred.
The thickness of the temporary support 22 is generally 2 to 200 μm, more preferably 5 to 50 μm, and still more preferably 10 to 30 μm. If the temporary support 22 is too thick, there may be a problem in handling properties and the like when the resin layer 20 is transferred using the laminated film 24 for resin layer formation.

  Note that the surface of the temporary support 22 may be subjected to a release treatment in addition to the mat treatment and the corona treatment.

(Resin layer 20)
The resin layer 20 is a layer containing a polymer having a functional group and a polymerizable group that interact with the plating catalyst or its precursor. The resin layer 20 adsorbs a later-described plating catalyst or a precursor thereof according to the function of the functional group that forms an interaction with the plating catalyst or the precursor in the polymer. That is, the resin layer 20 functions as a good receiving layer for the plating catalyst (or its precursor). Moreover, a polymeric group is utilized for the coupling | bonding between polymers, and the coupling | bonding with the insulating layer 16 (or adhesion assistance layer 30 mentioned later). As a result, excellent adhesion with the metal layer 28 formed on the surface of the resin layer 20 is obtained.

Although the thickness in particular of the resin layer 20 is not restrict | limited, 0.02-5.0 micrometers is preferable from the point which cuts out the resin layer of 18 parts of via holes, and 0.05-3.0 micrometers is more preferable.
Further, the surface roughness (Ra) of the resin layer 20 is preferably 0.005 to 0.3 [mu] m, and more preferably 0.01 to 0.15 [mu] m, from the viewpoint of high-definition wiring formation. In addition, the surface roughness (Ra) was measured using Surfcom 3000A (manufactured by Tokyo Seimitsu Co., Ltd.) based on Ra described in JIS B 0601 (Revision of 201010120) by non-contact interference method.

The formation method of the resin layer 20 on the temporary support 22 is not particularly limited, and a known layer formation method such as a coating method, a transfer method, or a printing method is used. Specifically, the polymer may be laminated on the temporary support 22 with an extruder to form the resin layer 20, or a composition containing the polymer (hereinafter referred to as a resin layer forming composition as appropriate). May be used.
When using a composition, the method of immersing the temporary support body 22 in the composition for resin layer formation, and the method of apply | coating the composition for resin layer formation on the temporary support body 22 are mentioned.
From the viewpoint of handleability and production efficiency, an embodiment in which the resin layer forming composition is formed by coating and drying the resin layer forming composition on the temporary support 22 is preferable.
The aspect of the resin layer forming composition will be described in detail later.

When the resin layer forming composition is brought into contact with the temporary support 22, the coating amount is 0.1 to 10 g in terms of solid content from the viewpoint of sufficient interaction with a plating catalyst or a precursor thereof described later. / M ² is preferable, and 0.5 to 5 g / m ² is particularly preferable.
Moreover, when a solvent is contained in the composition for resin layer formation, it may be allowed to stand at 20 ° C. to 40 ° C. for 0.5 hour to 2 hours between application and drying to remove the remaining solvent. .
Thus, the laminated film 24 for resin layer formation which has the resin layer 20 on the temporary support body 22 surface can be obtained.

  Below, the polymer used for formation of the resin layer 20 and the composition for resin layer formation are explained in full detail.

<Polymer>
The polymer has a functional group that interacts with the plating catalyst or its precursor (also referred to as an interactive group as appropriate) and a polymerizable group.

(Interactive group)
Examples of interactive groups include polar groups (hydrophilic groups), non-dissociative functional groups such as groups capable of forming multidentate coordination, nitrogen-containing functional groups, sulfur-containing functional groups, and oxygen-containing functional groups (by dissociation). Functional groups that do not generate protons).

The polar group may be a functional group having a positive charge such as ammonium or phosphonium, or an acid having a negative charge such as a sulfonic acid group, a carboxyl group, a phosphoric acid group, or a phosphonic acid group or capable of dissociating into a negative charge. Groups. These adsorb metal ions in the form of counterions of dissociating groups.
In addition, for example, nonionic polar groups such as a hydroxyl group, an amide group, a sulfonamide group, and an alkoxy group can also be used.
In addition, imino groups, primary and secondary amino groups, amide groups, urethane groups, hydroxyl groups (including phenols), thiol groups, and the like can also be used.

Further, as the non-dissociable functional group, specifically, a group capable of forming a coordination with a metal ion, a nitrogen-containing functional group, a sulfur-containing functional group, an oxygen-containing functional group and the like are preferable. Specifically, imide group, pyridine group, tertiary amino group, ammonium group, pyrrolidone group, amidino group, group containing triazine ring structure, group containing isocyanuric structure, nitro group, nitroso group, azo group, diazo group , Nitrogen-containing functional groups such as azide group, cyano group, cyanate group (R—O—CN), ether group, carbonyl group, ester group, group containing N-oxide structure, group containing S-oxide structure, thioether group , Sulfur-containing functional groups such as thioxy group, sulfoxide group, sulfone group, sulfite group, group containing sulfoxyimine structure, group containing sulfoxynium salt structure, group containing sulfonic acid ester structure, phosphorus-containing functional group such as phosphine group A group containing a halogen atom such as a group, chlorine or bromine. In addition, an imidazole group, a urea group, or a thiourea group may be used as long as it is non-dissociative due to a relationship with an adjacent atom or atomic group.
Among them, a carboxylic acid group, an ether group, or a cyano group is particularly preferable because of its high polarity and high adsorption ability to a plating catalyst or the like, and a carboxylic acid group or a cyano group is most preferable.
Moreover, it is preferable that both the cyano group and the carboxylic acid group are contained as an interactive group in the polymer from the viewpoint that the connection reliability and yield of the obtained multilayer wiring board are more excellent.

In addition, as said ether group, the polyoxyalkylene group represented by the following formula | equation (A) is preferable.
Formula (A) *-(YO) _n -R ^c
In formula (A), Y represents an alkylene group and R ^c represents an alkyl group. n represents a number from 1 to 30. * Represents a bonding position.
As an alkylene group, C1-C3 is preferable and, specifically, an ethylene group and a propylene group are mentioned preferably.
As an alkyl group, C1-C10 is preferable and a methyl group and an ethyl group are mentioned preferably specifically ,.
n represents the number of 1-30, Preferably it is 3-23. In addition, n represents an average value, and the numerical value can be measured by a known method (NMR) or the like.

(Polymerizable group)
The polymerizable group is a functional group capable of forming a bond between polymers or between the polymer and the insulating layer 16 (or the adhesion assisting layer 30 described later) by applying energy, for example, a radical polymerizable group, And cationically polymerizable groups. Of these, a radical polymerizable group is preferable from the viewpoint of reactivity. Examples of the radical polymerizable group include unsaturated carboxylic acid ester groups such as acrylic acid ester groups, methacrylic acid ester groups, itaconic acid ester groups, crotonic acid ester groups, isocrotonic acid ester groups, maleic acid ester groups, styryl groups, Examples thereof include a vinyl group, an acrylamide group, and a methacrylamide group. Among these, a methacrylic acid ester group (methacryloyl group), an acrylic acid ester group (acryloyl group), a vinyl group, a styryl group, an acrylamide group, and a methacrylamide group are preferable, and an acryloyl group, a methacryloyl group, and a styryl group are particularly preferable.

  Examples of the polymer having a polymerizable group and an interactive group include homopolymers and copolymers obtained using a monomer having an interactive group, such as a vinyl group, an allyl group, and a (meth) acryl group. A polymer having an ethylene addition polymerizable unsaturated group (polymerizable group) introduced therein is preferable, and the polymer having a polymerizable group and an interactive group has a polymerizable group at least at the main chain terminal or side chain. And those having a polymerizable group in the side chain are preferred.

The method for synthesizing such a polymer having a polymerizable group and an interactive group is not particularly limited, and a known synthesis method (see paragraphs [0097] to [0125] of Patent Publication 2009-280905) is used.
For example, when it has a double bond group as a polymerizable group, it can be synthesized as follows. As synthesis methods, i) a method in which a monomer having an interactive group and a monomer having a polymerizable group are copolymerized, and ii) a monomer having an interactive group and a monomer having a double bond precursor are copolymerized. And then introducing a double bond by treatment with a base or the like, iii) reacting a polymer having an interactive group with a monomer having a polymerizable group to introduce a double bond (introducing a polymerizable group) ) Method. Preference is given to methods ii) and iii) from the viewpoint of synthesis suitability.

Although the weight average molecular weight of a polymer is not specifically limited, 1000 or more and 700,000 or less are preferable, More preferably, it is 2000 or more and 200,000 or less. In particular, from the viewpoint of polymerization sensitivity, the weight average molecular weight is preferably 20000 or more.
Moreover, as a polymerization degree of a polymer, it is preferable to use a 10-mer or more thing, More preferably, it is a 20-mer or more thing. Moreover, 7000-mer or less is preferable, 3000-mer or less is more preferable, 2000-mer or less is still more preferable, 1000-mer or less is especially preferable.

(Preferred embodiment)
As a preferred embodiment of the polymer, a polymer having a unit (polymerizable group-containing unit) represented by the following formula (1) can be mentioned. By including the unit in the polymer, excellent adhesion between the resin layer 20 and the insulating layer 16 is expressed, and a crosslinking reaction proceeds in the film, so that a film having excellent strength can be obtained.

In formula (1), R < ¹ > -R < ⁴ > represents a hydrogen atom or a substituted or unsubstituted alkyl group each independently.
When R < ¹ > -R < ⁴ > is a substituted or unsubstituted alkyl group, a C1-C6 alkyl group is preferable and a C1-C4 alkyl group is more preferable. More specifically, examples of the unsubstituted alkyl group include a methyl group, an ethyl group, a propyl group, and a butyl group, and examples of the substituted alkyl group include a methyl group, an ethyl group, A propyl group and a butyl group are mentioned.

R ¹ is preferably a hydrogen atom or a methyl group.
R ² is preferably a hydrogen atom or a methyl group.
R ³ is preferably a hydrogen atom.
R ⁴ is preferably a hydrogen atom.

  Y and Z each independently represent a single bond or a substituted or unsubstituted divalent organic group. Examples of the divalent organic group include a substituted or unsubstituted aliphatic hydrocarbon group (preferably having 1 to 3 carbon atoms), a substituted or unsubstituted aromatic hydrocarbon group (preferably having 6 to 12 carbon atoms), -O —, —S—, —N (R) — (R: alkyl group), —CO—, —NH—, —COO—, —CONH—, or a combination thereof (eg, alkyleneoxy group, alkyleneoxy group) Carbonyl group, alkylenecarbonyloxy group, etc.).

As the substituted or unsubstituted aliphatic hydrocarbon group, a methylene group, an ethylene group, a propylene group, a butylene group, a pentylene group, a hexylene group, or a group in which these groups are substituted with a methoxy group or the like is preferable.
The substituted or unsubstituted aromatic hydrocarbon group is preferably an unsubstituted phenylene group or a phenylene group substituted with a methoxy group or the like.
Among them, — (CH ₂ ) _n — (n is an integer of 1 to 3) is preferable, and —CH ₂ — is more preferable.

  Y and Z are preferably an ester group (—COO—), an amide group (—CONH—), an ether group (—O—), or a substituted or unsubstituted aromatic hydrocarbon group.

L ¹ represents a substituted or unsubstituted divalent organic group. The definition of a divalent organic group is synonymous with the organic group represented by said Y and Z, for example, a substituted or unsubstituted aliphatic hydrocarbon group, a substituted or unsubstituted aromatic hydrocarbon group, -O —, —S—, —N (R) — (R: alkyl group), —CO—, —NH—, —COO—, —CONH—, or a combination thereof.

L ¹ is preferably an unsubstituted alkylene group or a divalent organic group having a urethane bond or urea bond, more preferably an unsubstituted alkylene group or a divalent organic group having a urethane bond, and the total number of carbon atoms. Those having 1 to 9 are particularly preferred. Incidentally, the total number of carbon atoms of L ^1, means the total number of carbon atoms contained in the substituted or unsubstituted divalent organic group represented by L ^1.
More specifically, the structure of L ¹ is preferably a structure represented by Formula (1-1) or Formula (1-2).

In formula (1-1) and formula (1-2), R ^a and R ^b each independently represent a divalent organic group. The definition of the divalent organic group is the same as described above. Preferably, a substituted or unsubstituted alkylene group such as a methylene group, an ethylene group, a propylene group, or a butylene group, or an ethylene oxide group, a diethylene oxide group, Examples thereof include polyoxyalkylene groups such as ethylene oxide group, tetraethylene oxide group, dipropylene oxide group, tripropylene oxide group and tetrapropylene oxide group.

  A preferred embodiment of the unit represented by the formula (1) includes a unit represented by the formula (1-A).

In the formula (1-A), R ¹ , R ² , X and L ¹ are the same as the definitions of each group in the unit represented by the formula (1). T represents an oxygen atom or NR (R represents a hydrogen atom or an alkyl group, preferably a hydrogen atom or an unsubstituted alkyl group having 1 to 5 carbon atoms).

  A preferred embodiment of the unit represented by the formula (1-A) is a unit represented by the formula (1-B).

In formula (1-B), R ¹ , R ² , and L ¹ are the same as defined for each group in the unit represented by formula (1-A). V and T represent an oxygen atom or NR (R represents a hydrogen atom or an alkyl group, preferably a hydrogen atom or an unsubstituted alkyl group having 1 to 5 carbon atoms).

In the above formula (1-B), T is preferably an oxygen atom.
In the above formulas (1-A) and (1-B), L ¹ is preferably an unsubstituted alkylene group or a divalent organic group having a urethane bond or a urea bond. A valent organic group is more preferable, and a group having 1 to 9 carbon atoms is particularly preferable.

  Although the content of the unit represented by the formula (1) in the polymer is not particularly limited, it is based on the reactivity (polymerization and curability) and the adhesion to the insulating layer with respect to all units (100 mol%). 5 to 50 mol% is preferable, and 5 to 40 mol% is more preferable. When the amount is less than 5 mol%, the reactivity (curability and polymerizability) may be reduced. When the amount exceeds 50 mol%, gelation is likely to occur during the synthesis of the polymer, and the control of the reaction becomes difficult.

  As a preferred embodiment of the polymer, a polymer having a unit (interactive group-containing unit) represented by the following formula (2) is exemplified. By including the unit in the polymer, the adsorptivity to the plating catalyst or a precursor thereof described later is improved, and excellent adhesion between the resin layer 20 and the metal film 28 described later is ensured.

In formula (2), R ⁵ represents a hydrogen atom or a substituted or unsubstituted alkyl group. The substituted or unsubstituted alkyl group represented by R ⁵ has the same meaning as the substituted or unsubstituted alkyl group represented by R ^{1 to} R ⁴ described above.
R ⁵ is preferably a hydrogen atom, a methyl group, or a methyl group substituted with a hydroxy group or a bromine atom.

X and L ² each independently represents a single bond or a substituted or unsubstituted divalent organic group. The definition of the divalent organic group is synonymous with the divalent organic group represented by Z and Y, for example, a substituted or unsubstituted aliphatic hydrocarbon group, a substituted or unsubstituted aromatic hydrocarbon group. , -O-, -S-, -N (R)-(R: alkyl group), -CO-, -NH-, -COO-, -CONH-, or a combination thereof.

  X preferably includes a single bond, an ester group (—COO—), an amide group (—CONH—), an ether group (—O—), or a substituted or unsubstituted aromatic hydrocarbon group, and more preferably. Are a single bond, an ester group (—COO—), and an amide group (—CONH—).

L ² is preferably a linear, branched, or cyclic alkylene group, an aromatic group, or a group obtained by combining these. The group obtained by combining the alkylene group and the aromatic group may further be via an ether group, an ester group, an amide group, a urethane group, or a urea group.
Among these, L ² preferably has 1 to 15 total carbon atoms, and particularly preferably unsubstituted. Incidentally, the total number of carbon atoms of L ^2, means the total number of carbon atoms contained in the substituted or unsubstituted divalent organic group represented by L ^2.
Specifically, a methylene group, an ethylene group, a propylene group, a butylene group, a phenylene group, and those groups substituted with a methoxy group, a hydroxy group, a chlorine atom, a bromine atom, a fluorine atom, etc., The group which combined these is mentioned.

  W represents a functional group (interactive group) that forms an interaction with the plating catalyst or a precursor thereof, and the definition thereof is as described above. Of these, a cyano group or a carboxylic acid group is preferable because it is excellent in adsorptivity to the plating catalyst or its precursor.

  In the polymer, the unit represented by the formula (2) of two or more different types of W may be included, and the connection reliability and yield of the obtained multilayer wiring board are more excellent. It is preferable that a unit represented by the formula (2) in which W is a cyano group and a unit represented by the formula (2) in which W is a carboxylic acid group are included.

  A preferred embodiment of the unit represented by the formula (2) is a unit represented by the formula (2-A).

In said formula (2-A), R < ⁵ >, L < ² > and W are the same as the definition of each group in the unit represented by Formula (2). U represents an oxygen atom or NR ′ (R ′ represents a hydrogen atom or an alkyl group, preferably a hydrogen atom or an unsubstituted alkyl group having 1 to 5 carbon atoms).

L ² in the formula (2-A) is a linear, branched, or cyclic alkylene group, an aromatic group (in particular, a divalent aromatic hydrocarbon group is preferable), or a combination thereof. Is preferred.
In particular, in the formula (2-A), the connecting site with W in L ² is preferably a divalent organic group having a linear, branched, or cyclic alkylene group. These organic groups preferably have 1 to 10 carbon atoms in total.
As another preferred embodiment, the connecting portion of the W in L ² in Formula (2-A) is preferably a divalent organic group having an aromatic group, and among them, the divalent organic The group preferably has a total carbon number of 6 to 15.

  The content of the unit represented by the formula (2) in the polymer is not particularly limited, but 5 to 94 mol% is preferable with respect to all units (100 mol%) in terms of adsorptivity to the plating catalyst and the like. 10-80 mol% is more preferable.

  The bonding mode of each unit in the polymer is not particularly limited, and may be a random polymer in which each unit is randomly bonded, or a block polymer in which each unit is connected to the same type to form a block portion. .

  In addition to the unit represented by the above formula (1) and the unit represented by the formula (2), the polymer may contain other units as long as the effects of the present invention are not impaired.

(Composition for resin layer formation)
The resin layer forming composition contains the polymer.
Although content of the polymer in the composition for resin layer formation is not restrict | limited in particular, 2-50 mass% is preferable with respect to the composition whole quantity, and 5-30 mass% is more preferable. If it is in the said range, it is excellent in the handleability of a composition and control of the layer thickness of the resin layer 20 is easy.

The resin layer forming composition may contain a solvent, if necessary, in addition to the polymer.
Examples of solvents that can be used include alcohol solvents such as methanol, ethanol, propanol, ethylene glycol, glycerin, and propylene glycol monomethyl ether, acids such as acetic acid, ketone solvents such as acetone, methyl ethyl ketone, and cyclohexanone, formamide, dimethylacetamide, Amide solvents such as N-methylpyrrolidone, nitrile solvents such as acetonitrile and propyronitrile, ester solvents such as methyl acetate and ethyl acetate, carbonate solvents such as dimethyl carbonate and diethyl carbonate, and other ether solvents A solvent, a glycol solvent, an amine solvent, a thiol solvent, a halogen solvent, etc. are mentioned.
Among these, amide solvents, ketone solvents, nitrile solvents, and carbonate solvents are preferable, and specifically, acetone, dimethylacetamide, methyl ethyl ketone, cyclohexanone, acetonitrile, propionitrile, N-methylpyrrolidone, and dimethyl carbonate are preferable. .

  The content of the solvent in the resin layer forming composition is not particularly limited, but is preferably 50 to 98% by mass, more preferably 70 to 95% by mass with respect to the total amount of the composition. If it is in the said range, it is excellent in the handleability of a composition and it is easy to control the layer thickness of the resin layer 20, etc.

  The resin layer forming composition further includes a surfactant, a plasticizer, a polymerization inhibitor, a curing agent, a radical generator, a sensitizer, a rubber component (for example, CTBN), a flame retardant (for example, (Phosphorous flame retardant), diluent, thixotropic agent, pigment, antifoaming agent, leveling agent, coupling agent and the like may be added.

The materials of the resin layer 20 and the insulating layer 16 described above are appropriately selected. From the viewpoint of low roughness and strong adhesion to metal, the polymer constituting the resin layer 20 is an acrylic polymer or a methacrylic polymer, and is insulated. A combination in which the material constituting the layer 16 is an epoxy composition or polyimide is preferable.
Particularly preferred is a combination in which the polymer constituting the resin layer 20 is an acrylic polymer and the material constituting the insulating layer 16 is an epoxy composition.

<Process (E): Temporary support body peeling process>
At a process (E), a temporary support body is peeled from the laminated body obtained at the process (D).
More specifically, as shown in FIG. 1 (D), in this step, a temporary stack 26 including the resin layer forming laminated film 24 deposited on the insulating layer 16 in the step (D) is temporarily used. The support 22 is peeled off. By peeling off the temporary support 22, only the resin layer 20 in close contact with the insulating layer 16 remains in the laminate, and the resin layer 20 disposed on the via hole 18 is removed from the laminate 26 together with the temporary support 22. Is done.

  As the peeling condition of the temporary support 22, an optimum condition is appropriately selected according to the material used. Especially, from the point which removes the excess resin layer 20 which overlaps with the via hole 18 from the laminated body 26, 0-40 degreeC is preferable and the temperature of the resin layer 20 in a process (E) has more preferable 10-40 degreeC, 15-35 degreeC is further more preferable.

(Preferred embodiment)
In the step (E), the excess resin layer 20 overlapping the via hole 18 is easily removed, so that the interfacial peel strength σ (A1) per unit area between the resin layer 20 and the insulating layer 16, the resin layer 20, and the temporary support It is preferable that the interfacial peel strength σ (B1) per unit area of 22 and the breaking stress σ (C1) of the resin layer 20 satisfy the relationship of the following formula (X).
Formula (X) σ (A1)> σ (B1)> σ (C1)

In the above formula (X), in order to remove the excess resin layer 20 overlapping the via hole 18 from the substrate, the excess resin layer 20 overlapping the via hole 18 is first cut off, that is, the resin layer 20 is broken and temporarily removed. It is preferable to remove them together with the support 22 adhered, and for that purpose, σ (C1) is preferably the lowest.
Subsequently, in order for the temporary support 22 to peel off, the interfacial peel strength σ (B1) between the temporary support 22 and the resin layer 20 should be lower than the interfacial peel strength σ (A1) between the resin layer 20 and the insulating layer 16. preferable. If σ (B1) is too stronger than σ (A1), the resin layer 20 laminated in a predetermined region may be peeled off from the insulating layer 16 and a transfer failure may occur. Therefore, the above formula (X) means that the condition for removing the excess resin layer 20 overlapping the via hole 18 from the stacked body 26 is satisfied.

The interfacial peel strength σ (A1) per unit area between the resin layer 20 and the insulating layer 16 is preferably 50 to 500 MPa, and more preferably 100 to 400 MPa.
The interfacial peel strength σ (B1) per unit area between the resin layer 20 and the temporary support 22 is preferably 10 to 300 MPa, and more preferably 50 to 200 MPa.
The breaking stress σ (C1) of the resin layer 20 is preferably 0.01 to 150 MPa, and more preferably 0.05 to 100 MPa.

The difference between the interfacial peel strength σ (A1) and the interfacial peel strength σ (B1) is preferably 5 to 70 MPa because the excess resin layer 20 hardly remains in the laminate.
The difference between the interfacial peel strength σ (B1) and the breaking stress σ (C1) is preferably 20 to 70 MPa from the point that the excess resin layer 20 hardly remains in the laminate.

<Process (F): Plating process>
In the step (F), after the step (E), the plating catalyst or its precursor is applied to the wall surface of the via hole and the resin layer, and then plating is performed.
More specifically, as shown in FIG. 1E, a metal film 28 that is electrically connected to the metal wiring 14 can be formed by plating.

In this step, the interactive group mainly contained in the resin layer 20 adheres (adsorbs) the applied plating catalyst or its precursor depending on its function.
Examples of the plating catalyst or its precursor include those that function as a plating catalyst or an electrode in the plating treatment described later. Therefore, the type of the plating catalyst or its precursor is appropriately determined depending on the type of plating.
In addition, it is preferable that the plating catalyst used in this process or its precursor is an electroless plating catalyst or its precursor. Especially, it is preferable that a plating catalyst or its precursor is a compound containing Pd, Ag, or Cu from the point of a reduction potential.
Hereinafter, first, electroless plating or a precursor thereof will be described in detail.

(Electroless plating catalyst)
Any electroless plating catalyst can be used as long as it becomes an active nucleus at the time of electroless plating. Specifically, a metal having a catalytic ability for an autocatalytic reduction reaction (lower ionization tendency than Ni). And the like, specifically, Pd, Ag, Cu, Ni, Al, Fe, Co, and the like. Among them, those capable of multidentate coordination are preferable, and Ag, Pd, and Cu are particularly preferable in view of the number of types of functional groups capable of coordination and high catalytic ability.
A metal colloid may be used as the electroless plating catalyst. In general, a metal colloid can be prepared by reducing metal ions in a solution containing a charged surfactant or a charged protective agent. The charge of the metal colloid can be adjusted by the surfactant or protective agent used here.

(Electroless plating catalyst precursor)
The electroless plating catalyst precursor can be used without particular limitation as long as it can become an electroless plating catalyst by a chemical reaction. The metal ions of the metals mentioned as the electroless plating catalyst are mainly used. The metal ion that is an electroless plating catalyst precursor becomes a zero-valent metal that is an electroless plating catalyst by a reduction reaction. The electroless plating catalyst precursor is applied to the wall surface of the via hole 18 and the resin layer 20 and then, before being immersed in the electroless plating bath, the electroless plating catalyst is separately changed to a zero-valent metal by a reduction reaction. Alternatively, the electroless plating catalyst precursor may be immersed in an electroless plating bath and changed to a metal (electroless plating catalyst) by a reducing agent in the electroless plating bath.

The metal ions that are the electroless plating catalyst precursor are preferably imparted to the wall surface of the via hole 18 and the resin layer 20 (inside the resin layer 20 and its surface) using a metal salt. The metal salt used is not particularly limited as long as it is dissolved in a suitable solvent and dissociated into a metal ion and a base (anion), and M (NO ₃ ) _n , MCl _n , M _{2 / n} (SO ₄ ), M _{3 / n} (PO ₄ ) Pd (OAc) _n (M represents an n-valent metal atom), and the like. As a metal ion, the thing which said metal salt dissociated can be used suitably. Specific examples include, for example, Ag ions, Cu ions, Al ions, Ni ions, Co ions, Fe ions, and Pd ions. Among them, those capable of multidentate coordination are preferable, and in particular, functionalities capable of coordination. In view of the number of types of groups and catalytic ability, Ag ions and Pd ions are preferable.

  One of preferred examples of the electroless plating catalyst or precursor thereof used in the present invention is a palladium compound. This palladium compound acts as a plating catalyst (palladium) or a precursor thereof (palladium ions), which acts as an active nucleus during the plating treatment and plays a role of depositing metal. The palladium compound is not particularly limited as long as it contains palladium and acts as a nucleus in the plating process, and examples thereof include a palladium (II) salt, a palladium (0) complex, and a palladium colloid.

Examples of the palladium salt include palladium acetate, palladium chloride, palladium nitrate, palladium bromide, palladium carbonate, palladium sulfate, bis (benzonitrile) dichloropalladium (II), bis (acetonitrile) dichloropalladium (II), and bis (ethylenediamine). ) Palladium (II) chloride and the like. Of these, palladium nitrate, palladium acetate, palladium sulfate, and bis (acetonitrile) dichloropalladium (II) are preferable in terms of ease of handling and solubility.
Examples of the palladium complex include tetrakistriphenylphosphine palladium complex and dipalladium trisbenzylideneacetone complex.
The palladium colloid is a particle composed of palladium (0), and its size is not particularly limited, but is preferably 5 nm to 300 nm, more preferably 10 nm to 100 nm, from the viewpoint of stability in the liquid. The palladium colloid may contain other metals as necessary, and examples of the other metals include tin. Examples of the palladium colloid include tin-palladium colloid. The palladium colloid may be synthesized by a known method or a commercially available product may be used. For example, a palladium colloid can be prepared by reducing palladium ions in a solution containing a charged surfactant or a charged protective agent.

(Other catalysts)
In this step, a zero-valent metal can be used as a catalyst used for direct electroplating without electroless plating. Examples of the zero-valent metal include Pd, Ag, Cu, Ni, Al, Fe, and Co. Among them, those capable of multidentate coordination are preferable, and in particular, adsorption (adhesion) to interactive groups. Pd, Ag, and Cu are preferable because of their high properties and high catalytic ability.

As a method of applying a metal that is an electroless plating catalyst or a metal salt that is an electroless plating catalyst precursor to the wall surface of the via hole 18 and the resin layer 20, a dispersion in which a metal is dispersed in an appropriate dispersion medium, or A metal salt is dissolved in an appropriate solvent to prepare a solution containing dissociated metal ions, and the dispersion or solution is applied onto the wall surface of the via hole 18 and the resin layer 20, or in the dispersion or solution. What is necessary is just to immerse the laminated body in which the resin layer 20 was formed.
Moreover, you may use the method of adding an electroless-plating catalyst or its precursor in the composition for resin layer formation in a process (E).
By applying a composition containing a polymer having a polymerizable group and an interactive group, and an electroless plating catalyst or a precursor thereof onto the temporary support 22, the composition has an interactive group, and The resin layer 20 containing a plating catalyst or its precursor can be formed.

(Organic solvent and water)
The plating catalyst or a precursor thereof as described above can be applied to the wall surface of the via hole 18 and the resin layer 20 as a dispersion or solution (catalyst solution). An organic solvent or water is used for the catalyst solution.
By containing the organic solvent, the permeability of the plating catalyst or its precursor to the wall surface of the via hole 18 and the resin layer 20 is improved, and the plating catalyst or its precursor can be efficiently adsorbed to the interactive group.

  Water may be used for the catalyst solution, and it is preferable that this water does not contain impurities. From such a viewpoint, it is preferable to use RO water, deionized water, distilled water, purified water, or the like. It is particularly preferable to use deionized water or distilled water.

  The organic solvent used for the preparation of the catalyst solution is not particularly limited as long as it is a solvent that can penetrate the wall surface of the via hole 18 and the resin layer 20, but specifically, acetone, methyl acetoacetate, ethyl acetoacetate, ethylene Glycol diacetate, cyclohexanone, acetylacetone, acetophenone, 2- (1-cyclohexenyl), propylene glycol diacetate, triacetin, diethylene glycol diacetate, dioxane, N-methylpyrrolidone, dimethyl carbonate, dimethyl cellosolve, and the like can be used.

  In particular, a water-soluble organic solvent is preferable from the viewpoints of compatibility with the plating catalyst or a precursor thereof, and permeability to the wall surface of the via hole 18 and the resin layer 20, and acetone, dimethyl carbonate, dimethyl cellosolve, triethylene glycol monomethyl. Ether, diethylene glycol dimethyl ether, and diethylene glycol diethyl ether are preferred.

The content of the solvent is preferably 0.5 to 40% by mass, more preferably 5 to 30% by mass, and particularly preferably 5 to 20% by mass with respect to the total amount of the catalyst solution.
In addition to the plating catalyst or its precursor and water as the main solvent, the plating catalyst solution may contain other additives depending on the purpose within a range not impairing the effects of the present invention. Examples of other additives include those shown below.
Examples include swelling agents (such as organic compounds such as ketones, aldehydes, ethers, esters, etc.) and surfactants (such as anionic, cationic, zwitterionic, nonionic, low molecular or polymeric). .

By bringing the plating catalyst or its precursor into contact with each other as described above, in particular, the interaction group in the resin layer 20 is interacted with an intermolecular force such as van der Waals force or distributed by a lone electron pair. The plating catalyst or its precursor can be adsorbed by utilizing the interaction due to the coordinate bond.
From the viewpoint of sufficiently performing such adsorption, the metal concentration in the dispersion, solution, composition, or metal ion concentration in the solution is preferably in the range of 0.001 to 50% by mass, More preferably, it is in the range of 0.005 to 30% by mass. Further, the contact time is preferably about 30 seconds to 24 hours, more preferably about 1 minute to 1 hour.
In the previous stage of this step (F), a plating catalyst or a precursor thereof can be applied to the wall surface of the via hole 18 and the resin layer 20, and in particular, an interactive group in the resin layer 20 and a plating catalyst or a precursor thereof An interaction can be formed between the two.

(Plating treatment)
Thereafter, the metal layer (plating film) 28 is formed on the surface of the resin layer 20 by plating the wall surface of the via hole 18 to which the electroless plating catalyst or its precursor is applied and the resin layer 20 [FIG. 1 (E)]. The formed metal layer 28 functions as a second metal wiring and has excellent conductivity and adhesion.
The thickness of the metal layer 28 is not particularly limited, but is preferably 0.2 to 30 μm, and more preferably 0.4 to 20 μm, in that wiring is formed by a semi-additive method and a subtractive method. The thickness means the thickness from the surface of the resin layer 20 to the surface of the metal layer 28 (corresponding to h in FIG. 1E).

The type of plating performed in this step includes electroless plating and electroplating, and can be appropriately selected depending on the function of the plating catalyst or its precursor. Especially, it is preferable to perform electroless plating from the point of the formation of the hybrid structure expressed in the resin layer 20, and the adhesive improvement. In order to obtain a plating layer having a desired film thickness, it is a more preferable aspect that electroplating is further performed after electroless plating.
Hereinafter, the plating suitably performed in this process will be described.

(Electroless plating)
Electroless plating refers to an operation of depositing a metal by a chemical reaction using a solution in which metal ions to be deposited as a plating are dissolved.
The electroless plating in this step is performed, for example, by immersing the laminate provided with the electroless plating catalyst in water to remove excess electroless plating catalyst (metal) and then immersing it in an electroless plating bath. As the electroless plating bath to be used, a generally known electroless plating bath can be used.

Further, when the laminate provided with the electroless plating catalyst precursor is immersed in an electroless plating bath in a state where the electroless plating catalyst precursor is adsorbed or impregnated on the wall surface of the via hole 18 and the resin layer 20, The body is washed with water to remove excess precursors (such as metal salts) and then immersed in an electroless plating bath. In this case, reduction of the plating catalyst precursor and subsequent electroless plating are performed in the electroless plating bath. As the electroless plating bath used here, a generally known electroless plating bath can be used as described above.
In addition, the reduction of the electroless plating catalyst precursor may be performed as a separate step before electroless plating by preparing a catalyst activation liquid (reducing liquid) separately from the embodiment using the electroless plating liquid as described above. Is possible. The catalyst activation liquid is a liquid in which a reducing agent capable of reducing an electroless plating catalyst precursor (mainly metal ions) to zero-valent metal is dissolved, and its concentration is preferably 0.1 to 50% by mass, and 1 to 30% by mass. % Is more preferable. As the reducing agent, it is possible to use a boron-based reducing agent such as sodium borohydride or dimethylamine borane, or a reducing agent such as formaldehyde or hypophosphorous acid.

  As a composition of a general electroless plating bath, in addition to a solvent, 1. metal ions for plating; 2. reducing agent; Additives (stabilizers) that improve the stability of metal ions are mainly included. In addition to these, the plating bath may contain known additives such as a plating bath stabilizer.

  Examples of the solvent used for the electroless plating bath include water and organic solvents. As the organic solvent, it is necessary to be a solvent that can be used for water, and from this point, ketones such as acetone and alcohols such as methanol, ethanol, and isopropanol are preferably used.

  Copper, tin, lead, nickel, gold, palladium, and rhodium are known as the types of metals used in the electroless plating bath, and copper and gold are particularly preferable from the viewpoint of conductivity. Moreover, the optimal reducing agent and additive are suitably selected according to the said metal.

  The immersion time in the plating bath is preferably about 1 minute to 6 hours, and more preferably about 1 minute to 3 hours.

(Electroplating)
In this step, when the applied plating catalyst or its precursor has a function as an electrode, electroplating is performed on the wall surface of the via hole 18 and the resin layer 20 to which the catalyst or its precursor is applied. be able to. In addition, after the above-described electroless plating, the formed plating film may be used as an electrode, and electroplating may be further performed. As a result, a new metal layer 28 having an arbitrary thickness can be easily formed on the electroless plating film having excellent adhesion to the substrate. Thus, by performing electroplating after electroless plating, the metal layer 28 can be formed to a thickness according to the purpose.

  As a method of electroplating, a conventionally known method can be used. Examples of the metal used for electroplating include copper, chromium, lead, nickel, gold, silver, tin, and zinc. From the viewpoint of conductivity, copper, gold, and silver are preferable, and copper is more preferable. preferable.

  The thickness of the metal layer obtained by electroplating varies depending on the application, and can be controlled by adjusting the concentration of metal contained in the plating bath or the current density.

In the present invention, the metal deposited in the resin layer 20 by plating treatment (electroless plating or electroplating) is formed as a fractal microstructure in the layer, whereby the metal layer 28 and the resin are formed. Adhesion with the layer 20 can be further improved.
The amount of metal present in the resin layer 20 is such that when the cross section of the substrate is photographed with a metal microscope, the proportion of the metal in the region from the outermost surface of the resin layer 20 to a depth of 0.5 μm is 5 to 50 area%. In addition, when the arithmetic average roughness Ra (JIS B0633-2001) between the resin layer 20 and the metal interface is 0.05 μm to 0.5 μm, stronger adhesion is expressed.

  As described above, in the present invention, through the above-described steps (A) to (F), a multilayer wiring board having a fine wiring and an interlayer connection by vias is manufactured.

<Optional step (K): Energy application step>
You may provide the process of providing energy with respect to the resin layer 20 arrange | positioned on the insulating layer 16 between the said process (E) and a process (F). By providing the step, the reaction between the polymers proceeds via the polymerizable group, and the polymer in the resin layer 20 generates a direct chemical bond with the surface of the adjacent insulating layer 16. A strongly bonded resin layer 20 can be formed.

(Energy application method)
Examples of the method for imparting energy include exposure or heating. In the case of exposure, for example, radiation irradiation can be used. For example, light irradiation with a UV lamp, visible light, or the like is possible. Examples of the light source include a mercury lamp, a metal halide lamp, a xenon lamp, a chemical lamp, and a carbon arc lamp. Examples of radiation include electron beams, X-rays, ion beams, and far infrared rays. Further, g-line, i-line, deep-UV light, and high-density energy beam (laser beam) are also used.
In addition, a heating method using a thermal recording head or the like, a scanning exposure method using an infrared laser, or the like, and a high-illuminance flash exposure such as a xenon discharge lamp or an infrared lamp exposure are also preferable methods.
The time required for energy application varies depending on the structure of the polymer used and the light source, but is usually between 10 seconds and 5 hours.

When energy is applied by exposure, the exposure power is in the range of 10 to 10000 mJ / cm ² in order to facilitate the graft polymerization and to suppress the decomposition of the produced graft polymer. Is more preferable, and more preferably in the range of 50 to 7000 mJ / cm ² .

<Second Embodiment>
As another embodiment (also referred to as second embodiment) of the method for producing a multilayer wiring board of the present invention, instead of the above steps (C) and (D), the following steps (G) to (J) The embodiment which implements these in this order is mentioned.
(G) After step (C), a laminated film for forming an adhesion auxiliary layer provided with a temporary support and an adhesion auxiliary layer on the temporary support, and an insulating layer and an insulating layer subjected to desmear treatment on the insulating layer After the step (H) of obtaining a laminate by laminating the layers so as to contact each other and the step (G) of separating the temporary support from the laminate (I) after the step (H), the temporary support and the temporary support A laminated film for forming a resin layer comprising a resin layer containing a functional group that forms an interaction with the plating catalyst or its precursor and a polymer containing a polymerizable group on the adhesion auxiliary layer, and a resin layer Lamination so that the adhesion auxiliary layer is in contact, and obtaining a laminate (J) After step (I), the step of peeling the temporary support from the laminate. In the second embodiment, the adhesion assistance layer is insulated. The adhesion between the resin layer and the resin layer is improved, and The yield of the layer wiring board is further improved.
Below, the procedure of said each process is demonstrated.

<Process (G): Laminate formation process>
In the step (G), after the step (C), a temporary support and a laminated film for forming an adhesion auxiliary layer including an adhesion auxiliary layer on the temporary support are formed on the insulating layer, and the adhesion auxiliary layer and the desmear treatment are performed. Lamination is performed so that the applied insulating layer is in contact with each other to obtain a laminate.
More specifically, as shown in FIG. 2A, in this step, the adhesion is provided with the temporary support 22 and the adhesion auxiliary layer 30 provided on the temporary support 22 on the insulating layer 16. The laminated film 32 for forming the auxiliary layer is laminated so that the adhesion auxiliary layer 30 is in contact with the insulating layer 16 to obtain a laminated body 34.

The method of laminating the laminated film 32 for forming the adhesion auxiliary layer on the insulating layer 16 so that the adhesion auxiliary layer 30 is in contact with the insulating layer 16 is not particularly limited. Also good.
The temperature T of the adhesion assisting layer 30 when laminating the adhesion assisting layer forming laminated film 32 is equal to or higher than the glass transition temperature of the adhesion assisting layer as in the above-described condition of the resin layer 20 in the step (D), and the glass transition temperature. + 60 ° C. or lower. A preferred embodiment is the same as the resin layer 20 described above.
Moreover, the preferable range of the glass transition temperature of the adhesion auxiliary layer 30 is the same as the range of the resin layer 20 described above.
The Young's modulus of the adhesion assisting layer 30 is 0.16 × 10 ^{6 to} 100 × 10 ⁶ Pa, similarly to the condition of the resin layer 20 in the step (D) described above. A preferable range of Young's modulus is the same as that of the resin layer 20.
Furthermore, the elongation at break of the adhesion auxiliary layer 30 is 100% or less, as in the condition of the resin layer 20 in the step (D) described above. A preferable range of elongation at break is the same as that of the resin layer 20.

  A preferable range of the pressure (pressure bonding pressure) P applied to the adhesion auxiliary layer forming laminated film 32 in order to assist adhesion between the adhesion auxiliary layer 30 and the insulating layer 16 during lamination is applied to the resin layer forming laminated film. Same as the pressure range.

  Also in the step (G), as in the step (D) described above, the temperature T of the adhesion assisting layer 30 during lamination, the Young's modulus E (T) of the adhesion assisting layer 30 at the temperature T, and the fracture of the adhesion assisting layer 30 The point P is in the above range, and the pressure P applied to the adhesion auxiliary layer forming laminated film 32 and Log (E (T)) are expressed by the above formulas (I) to (IV) shown in FIG. It exists in the range surrounded by the straight line represented.

(Laminated film for forming adhesion auxiliary layer)
Next, the temporary support 22 and the adhesion auxiliary layer 30 constituting the adhesion auxiliary layer forming laminated film 32 used in this step will be described in detail.
The temporary support 22 is as described above, and the preferred embodiment is the same as described above.

(Adhesion auxiliary layer 30)
The adhesion auxiliary layer 30 serves to assist the adhesion between the insulating layer 16 and the resin layer 20.
The adhesion assisting layer 30 gives an active species as a starting point of the binding reaction with the resin layer 20, and can generate a large number of bonds between the adhesion assisting layer 30 and the resin layer 20 from the starting point. For example, it is useful when using a surface graft polymerization method or the like.
More specifically, as the adhesion auxiliary layer 30, a layer containing a polymerization initiator (polymerization initiation layer), a layer having a functional group capable of initiating polymerization (polymerization initiation layer), or the like can be used.

The thickness of the adhesion auxiliary layer 30 is not particularly limited, but is preferably 0.1 to 10 μm, and more preferably 0.2 to 5 μm from the viewpoint of maintaining film properties and preventing film peeling.
In mass after drying it is preferably 0.1 to 20 g / m ^2, more preferably ^{0.1~15g / m 2, 0.1~2g / m} 2 is more preferable.

The method for forming the adhesion assisting layer 30 on the temporary support 22 is not particularly limited, and a known layer forming method such as a coating method, a transfer method, or a printing method is used. Specifically, the adhesion auxiliary layer 30 may be formed by laminating necessary components on the temporary support 22 with an extruder, or a composition containing necessary components may be used. When using a composition, the method of immersing the temporary support body 22 in a composition and the method of apply | coating a composition on the temporary support body 22 are mentioned.
From the viewpoint of handleability and production efficiency, an embodiment in which the adhesion assisting layer 30 is formed by coating and drying the composition on the temporary support 22 is preferable.

For example, when the insulating layer 16 formed on the wiring substrate 10 is made of a known insulating resin that has been used as a material for a multilayer laminate, a build-up substrate, or a flexible substrate, it is in close contact with the insulating layer 16. From the viewpoint of property, it is preferable to use an insulating resin composition similar to that used for forming the insulating layer 16 as the resin composition used when forming the adhesion assisting layer 30.
Hereinafter, the aspect of the close_contact | adherence auxiliary | assistant layer formed from an insulating resin composition is demonstrated.

The insulating resin composition used when forming the adhesion assisting layer 30 may contain the same electrically insulating resin that constitutes the insulating layer 16 formed on the wiring substrate 10, and is different. However, it is preferable to use materials having similar thermal properties such as glass transition point, elastic modulus, and linear expansion coefficient. Specifically, for example, it is preferable in terms of adhesion to use the same type of insulating resin as the insulating resin constituting the insulating layer 16 formed on the wiring substrate 10.
In addition, inorganic or organic particles may be added in order to increase the strength of the adhesion auxiliary layer 30 and to improve electrical characteristics.

  Specific examples of the insulating resin may be, for example, a thermosetting resin, a thermoplastic resin, or a mixture thereof. Examples of the thermosetting resin include an epoxy resin, a phenol resin, a polyimide resin, a polyester resin, and a bismaleimide. Examples thereof include resins, polyolefin resins, isocyanate resins and the like.

  Examples of the thermoplastic resin include phenoxy resin, polyether sulfone, polysulfone, polyphenylene sulfone, polyphenylene sulfide, polyphenyl ether, polyether imide, and the like.

  Furthermore, the adhesion auxiliary layer 30 may contain a compound having a polymerizable double bond, specifically an acrylate or methacrylate compound, in order to promote crosslinking within the layer, It is preferable to use one.

  As long as the adhesion auxiliary layer 30 does not impair the effects of the present invention, various compounds can be added depending on the purpose. Specific examples include materials such as rubber and SBR latex that can relieve stress during heating, binders for improving film properties, plasticizers, surfactants, viscosity modifiers, and the like.

  Furthermore, the adhesion auxiliary layer 30 may be filled with a filler (for example, inorganic filler such as silica, alumina, clay, talc, aluminum hydroxide, calcium carbonate, cured epoxy resin, crosslinked benzoguanamine resin, crosslinked acrylic polymer, etc. Organic fillers), colorants, flame retardants, adhesion-imparting agents, silane coupling agents, antioxidants, ultraviolet absorbers and the like may be added singly or in combination.

  When adding these materials, it is preferable to add in the range of 0-200 mass% with respect to resin used as a main component, More preferably, it adds in the range of 0-80 mass%. When the adhesion auxiliary layer 30 and the material constituting the adjacent layer exhibit the same or close physical property values to heat and electricity, these additives need not necessarily be added.

The close adhesion auxiliary layer 30 preferably contains an active species (compound) that generates an active site capable of forming an interaction with the polymer compound constituting the resin layer 20. In order to generate this active site, some energy may be applied, and preferably, light (ultraviolet light, visible light, X-ray, etc.), plasma (oxygen, nitrogen, carbon dioxide, argon, etc.), heat, electricity, Etc. are used. Furthermore, active sites may be generated by chemically decomposing the surface with an oxidizing liquid (potassium permanganate solution) or the like.
Examples of the active species include a polymerization initiator (for example, a thermal polymerization initiator, a photopolymerization initiator, a polymer containing a polymerizable group). Specifically, it is described in paragraph numbers [0043] and [0044] of JP-A-2007-154306.
The amount of the polymerization initiator to be contained in the adhesion auxiliary layer 30 is preferably 0.1 to 50% by mass, more preferably 1.0 to 30% by mass in terms of solid content.

<Process (H): Temporary support peeling process>
At a process (H), a temporary support body is peeled from the laminated body obtained at the process (G).
More specifically, as shown in FIG. 2B, in this step, the temporary support 22 is removed from the laminate 34 including the adhesion auxiliary layer forming laminate film 32 deposited on the insulating layer 16. Peel off. By peeling off the temporary support 22, only the adhesion assisting layer 30 in close contact with the insulating layer 16 remains in the laminate, and the adhesion assisting layer 30 disposed on the via hole 18 is laminated with the temporary support 22. Removed from.

  As the peeling condition of the temporary support 22, an optimum condition is appropriately selected according to the material used. Especially, the point of the adhesion auxiliary layer 30 in the step (H) is preferably 0 to 40 ° C., more preferably 10 to 40 ° C., and more preferably 15 to 35 from the point that the excessive adhesion auxiliary layer 30 hardly remains in the laminate. More preferably.

(Preferred embodiment)
In the step (H), since the excessive adhesion auxiliary layer 30 hardly remains in the laminate, the interfacial peel strength σ (A2) per unit area between the adhesion auxiliary layer 30 and the insulating layer 16, the adhesion auxiliary layer 30, It is preferable that the interfacial peel strength σ (B2) per unit area with the temporary support 22 and the breaking stress σ (C2) of the adhesion auxiliary layer 30 satisfy the relationship of the following formula (Y).
Formula (Y) σ (A2)> σ (B2)> σ (C2)

In the above formula (Y), in order to remove the excessive adhesion auxiliary layer 30 overlapping the via hole 18 from the substrate, first, the excess adhesion auxiliary layer 30 overlapping the via hole 18 is cut off, that is, the adhesion auxiliary layer 30 breaks. Thus, it is preferable to remove them together with the temporary support 22 adhered, and for that purpose, σ (C2) is preferably the lowest.
Subsequently, in order for the temporary support 22 to peel off, the interfacial peel strength σ (B2) between the temporary support 22 and the close-contact auxiliary layer 30 is equal to the interfacial peel strength (A2) between the close-contact auxiliary layer 30 and the insulating layer 16. It is preferably lower than the interfacial peel strength. If σ (B2) is too stronger than σ (A2), the adhesion assisting layer 30 laminated in a predetermined region may be peeled off from the insulating layer 16 and a transfer failure may occur. Therefore, the above formula (Y) means that the condition for removing the excessive adhesion auxiliary layer 30 overlapping the via hole 18 from the stacked body 34 is satisfied.

The preferable range of the interfacial peel strength σ (A2) per unit area between the adhesion auxiliary layer 30 and the insulating layer 16 is the same as the preferable range of the interfacial peel strength σ (A1) described above.
The preferred range of the interfacial peel strength σ (B2) per unit area between the adhesion auxiliary layer 30 and the temporary support 22 is the same as the preferred range of the interfacial peel strength σ (B1) described above.
The preferable range of the breaking stress σ (C2) of the adhesion auxiliary layer 30 is the same as the preferable range of the breaking stress σ (C1) described above.

The difference between the interfacial peel strength σ (A2) and the interfacial peel strength σ (B2) is preferably 5 to 50 MPa from the point that the excessive adhesion assisting layer 30 hardly remains in the laminate.
The difference between the interfacial peel strength σ (B2) and the breaking stress σ (C2) is preferably 2 to 10 MPa from the point that the excessive adhesion auxiliary layer 30 hardly remains in the laminate.

<Process (I): Laminate formation process>
In step (I), after step (H), a resin layer containing a temporary support, a functional group that interacts with the plating catalyst or its precursor on the temporary support, and a polymer containing a polymerizable group. Is laminated on the adhesion auxiliary layer so that the resin layer and the adhesion auxiliary layer are in contact with each other to obtain a laminate.
More specifically, as shown in FIG. 2C, in this step, a resin including a temporary support 22 and a resin layer 20 provided on the temporary support 22 on the adhesion auxiliary layer 30. The layer-forming laminated film 24 is laminated so that the resin layer 20 is in contact with the adhesion auxiliary layer 30 to obtain a laminated body 36.

The laminated film 24 for forming a resin layer used is as described above.
The conditions for laminating are also the same as in the above step (D), and the preferred embodiment is also the same.

<Process (J): Temporary support peeling process>
At a process (J), a temporary support body is peeled from the laminated body obtained at the process (I).
More specifically, as shown in FIG. 2D, in this step, from the laminate 36 including the resin layer forming laminated film 24 deposited on the adhesion auxiliary layer 30 in the step (J), The temporary support 22 is peeled off. By peeling off the temporary support 22, only the resin layer 20 in close contact with the adhesion auxiliary layer 30 remains in the laminate, and the resin layer 20 disposed on the via hole 18 is removed from the laminate 36 together with the temporary support 22. Removed.

  As the peeling condition of the temporary support 22, an optimum condition is appropriately selected according to the material used. Especially, from the point which the excess resin layer 20 does not remain in a laminated body, 0-40 degreeC is preferable, as for the temperature of the resin layer 20 in a process (J), 10-40 degreeC is more preferable, and 15-35 degreeC is preferable. Further preferred.

(Preferred embodiment)
In the step (J), since the excess resin layer 20 hardly remains in the laminate, the interface peel strength σ (A3) per unit area between the resin layer 20 and the adhesion auxiliary layer 30 is expressed by the following formula (Z). It is preferable to satisfy the relationship.
Formula (Z) σ (A2), σ (A3)> σ (B1), σ (B2)> σ (C1), σ (C2)

  The interfacial peel strength σ (A3) per unit area of the adhesion auxiliary layer 30 and the adhesion auxiliary layer 30 is preferably 30 to 500 MPa, and more preferably 40 to 300 MPa.

  By performing the step (F) after the step (J), the metal film 28 that is electrically connected to the metal wiring 14 can be formed as shown in FIG.

The multilayer wiring board obtained by the above-described manufacturing method can also be used as a board serving as a core for forming further wiring so as to be suitable for mounting. As a method of laminating further wiring on the multilayer wiring board obtained by the forming method of the present invention, a known semi-additive method, subtractive method, or the like can be appropriately applied.
For example, first, a resist film is provided on the obtained multilayer wiring board, pattern exposure is performed, and development processing is performed to produce a pattern resist film. Thereafter, using the patterned resist film as a mask, a quick etching process is performed to remove the metal film in the non-pattern region, and then the patterned resist film is removed.

<Multilayer wiring board>
The multilayer wiring board obtained by the forming method of the present invention can be applied to various uses such as a semiconductor chip, various electric wiring boards, FPC, COF, TAB, a motherboard, a package interposer board, and the like.
In particular, the multilayer wiring board produced by the method of the present invention can easily form wiring with excellent adhesion to a smooth substrate, has good high-frequency characteristics, and is a fine high-density wiring. Excellent connection reliability between wires.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to these.

Below, the synthesis method of the polymer used in a present Example is explained in full detail.
(Synthesis Example 1: Polymer A)
A 1000 ml three-necked flask was charged with 35 g of N-methylpyrrolidone and heated to 75 ° C. under a nitrogen stream. There, N-methylpyrrolidone 35 g solution of 6.60 g of 2-hydroxyethyl acrylate (commercial product, manufactured by Tokyo Chemical Industry), 28.4 g of 2-cyanoethyl acrylate, and 0.65 g of V-601 (manufactured by Wako Pure Chemical Industries, Ltd.) The solution was added dropwise over 2.5 hours. After completion of dropping, the reaction solution was heated to 80 ° C. and further stirred for 3 hours. Thereafter, the reaction solution was cooled to room temperature.
Ditertiary butyl hydroquinone 0.29 g, dibutyltin dilaurate 0.29 g, Karenz AOI (manufactured by Showa Denko KK) 18.56 g, and N-methylpyrrolidone 19 g are added to the above reaction solution and reacted at 55 ° C. for 6 hours. Went. Thereafter, 3.6 g of methanol was added to the reaction solution, and the reaction was further performed for 1.5 hours. After completion of the reaction, reprecipitation was carried out with water, the solid matter was taken out, and 25 g of the polymer A of the present invention was obtained.

(Identification of structure)
Polymer A was dissolved in heavy DMSO and measured by Bruker 300 MHz NMR (AV-300). Peaks corresponding to nitrile group-containing units are broadly observed at 4.3-4.05 ppm (2H min), 2.9-2.8 ppm (2H min), 2.5-1.3 ppm (3H min), Peaks corresponding to the polymerizable group-containing units are 7.2 to 7.3 ppm (1 H min), 6.4 to 6.3 ppm (1 H min), 6.2 to 6.1 ppm (1 H min), 6.0 − 5.9ppm (1H min), 4.3-4.05ppm (6H min), 3.3-3.2ppm (2H min), 2.5-1.3ppm (3H min) broadly observed and polymerized It was found that the functional group-containing unit: nitrile group-containing unit = 22: 78 (mol ratio).

(Measurement of molecular weight)
Polymer A was dissolved in THF, and molecular weight was measured using Tosoh high speed GPC (HLC-8220GPC). As a result, a peak appeared at 23.75 minutes, and it was found that Mw = 5300 (Mw / Mn = 1.54) in terms of polystyrene.
In addition, the numerical value in the chemical formula of the following polymer A represents the mol% of each unit.

(Synthesis Example 2: Polymer B)
In a 1 L three-necked flask, 300 mL of ethyl acetate, 30 g of 2-hydroxyethyl methacrylate, and 19.8 g of pyridine were placed and cooled in an ice bath. Thereto was added dropwise 57 g of 2-bromoisobutyric acid bromide so that the internal temperature was 20 ° C. or less. Thereafter, the internal temperature was raised to room temperature (25 ° C.) and reacted for 2 hours. After completion of the reaction, 300 mL of distilled water was added to stop the reaction. Thereafter, the ethyl acetate layer was washed 4 times with 300 mL of distilled water, dried over magnesium sulfate, and ethyl acetate was distilled off. Thereafter, the monomer was purified by column chromatography to obtain 25 g.

  A 500 mL three-necked flask was charged with 28 g of N, N-dimethylacetamide and heated to 65 ° C. under a nitrogen stream. The monomer synthesized above: 20.9 g, acrylonitrile (Tokyo Chemical Industry Co., Ltd.) 4.0 g, acrylic acid (Tokyo Chemical Industry Co., Ltd.) 8.6 g, V-65 (Wako Pure Chemical Industries, Ltd.) 0.49 g N, N-dimethylacetamide 11.5 g solution was added dropwise over 4 hours. After completion of dropping, the mixture was further stirred for 3 hours. Thereafter, 173 g of N, N-dimethylacetamide was added, and the reaction solution was cooled to room temperature. To the above reaction solution, 0.13 g of 4-hydroxy TEMPO (manufactured by Tokyo Chemical Industry Co., Ltd.) and 66.8 g of 1,8-diazabicycloundecene were added and reacted at room temperature for 12 hours. Thereafter, 65 g of a 70 mass% methanesulfonic acid aqueous solution was added to the reaction solution. After completion of the reaction, reprecipitation was carried out with water, the solid matter was taken out, and 20 g of polymer B (weight average molecular weight 62,000) was obtained. When the acid value of the obtained specific polymer B was measured using a potentiometric automatic titrator (manufactured by Kyoto Electronics Industry Co., Ltd.) and a 0.1M sodium hydroxide aqueous solution as the titrant, the acid value of this polymer B was It was 3.2 mmol / g.

The obtained polymer B was identified using an IR measuring machine (manufactured by Horiba, Ltd.). The measurement was performed by dissolving the polymer in acetone and using KBr crystals. As a result of IR measurement, a peak was observed in the vicinity of 2240 cm ⁻¹ , and it was found that acrylonitrile, which is a nitrile unit, was introduced into the polymer. Moreover, it turned out that acrylic acid is introduce | transduced as a carboxylic acid unit by an acid value measurement. Moreover, it melt | dissolved in heavy DMSO (dimethyl sulfoxide), and measured by NMR (AV-300) of Bruker 300MHz. A peak corresponding to the nitrile group-containing unit is broadly observed at 2.5 to 0.7 ppm (5H min), and a peak corresponding to the polymerizable group-containing unit is 6.2 to a peak corresponding to the polymerizable group-containing unit. Broadly observed at 6.0 ppm (1H min), 5.8-6.0 ppm (1H min), 4.4-4.0 ppm (4H min), 2.5-0.7 ppm (8H min), A peak observed broad and a peak corresponding to a carboxylic acid group unit was observed broadly at 2.5 to 0.7 ppm (3H min), and a polymerizable group-containing unit: nitrile group-containing unit: carboxylic acid group unit = 31: 32 : 37 (mol ratio).

<Example 1>
[1. Step (X)]
A double-sided copper-clad plate (glass epoxy substrate) was CZ-treated (trade name: CZ-8100, manufactured by MEC Co., Ltd.) to finely roughen the copper surface.

[2. Step (Y)]
A dry film resist (DFR, trade name: RY3315, manufactured by Hitachi Chemical Co., Ltd.) was laminated on the finely roughened copper surface with a vacuum laminator at a pressure of 0.2 MPa at 70 ° C. After lamination, the copper pattern forming portion was subjected to mask exposure with an exposure machine having a central wavelength of 365 nm under the condition of 70 mJ / m ² . Thereafter, development was performed with a 1% aqueous sodium bicarbonate solution, followed by washing with water to obtain a resist pattern for subtractive etching.

[3. Step (Z)]
Next, a 40% cupric oxide solution at 45 ° C. was sprayed onto the obtained substrate until the copper in the non-resist portion where the resist pattern was not formed was etched. Thereafter, the obtained substrate was washed with water.

[4. Step (W)]
Next, in order to peel off the resist pattern, the substrate was immersed in a 4% NaOH aqueous solution at 45 ° C. for 60 seconds. Thereafter, the obtained substrate was washed with water and immersed in 1% sulfuric acid for 30 seconds. Thereafter, it was washed again with water.

[5. Step (A)]
Next, an epoxy insulating film GX-13 (film thickness 40 μm) manufactured by Ajinomoto Fine-Techno Co., Ltd. as an electrical insulating layer is applied to the substrate obtained in the step (W) at a pressure of 0.2 MPa using a vacuum laminator. The insulating film was formed by bonding under the condition of ° C. Thereafter, heat treatment was performed at 180 ° C. for 30 minutes.

[6. Step (B)]
A via hole reaching the copper foil having a top diameter of 60 μm and a bottom diameter of 50 μm was formed at a predetermined position on the insulating layer obtained in the step (A) by a CO ₂ laser.

[7. Step (C)]
Then, the desmear process was performed with respect to the surface in which the via hole was formed in the (B) process.
Specifically, an aqueous conditioner solution containing sodium hydroxide and a solvent was prepared as a conditioner solution, and the surface of the insulating layer was subjected to a swelling treatment by immersing at 75 ° C. for 10 minutes while stirring. Then, after processing for 3 minutes with 50 degreeC warm water, the desmear process was performed by immersing for 10 minutes at 85 degreeC, adding stirring using the sodium hydroxide aqueous solution containing potassium permanganate. Then, after immersing for 3 minutes in 50 degreeC warm water, the neutralization process was performed by immersing for 5 minutes at 45 degreeC, adding stirring using the neutralization aqueous solution containing a sulfuric acid.
By this desmear treatment, the insulating layer residue at the bottom of the via hole was removed. This was confirmed by the BSE image (reflection electron image) by the surface SEM.
In addition, the surface roughness (Ra) of the insulating layer after the desmear treatment was 0.8 μm.

[8. Step (D)]
First, the laminated film for resin layer formation used at a process (D) was produced with the following method.
Polymer A: 10.5 parts by mass, 73.3 parts by mass of acetone, 33.9 parts by mass of methanol, and 4.8 parts by mass of N, N-dimethylacetamide were mixed and stirred to prepare a coating solution.
The prepared coating solution is applied by spin coating onto a PET support having a film thickness of 32 μm by a spin coating method, dried at 80 ° C. for 20 minutes, and a resin layer having a resin layer having a thickness of 0.5 μm A laminated film for formation was obtained.
The obtained laminated film was laminated on the insulating layer having the via hole obtained in the step (C) while applying a predetermined pressure (pressing) to obtain a laminated body. The pressure condition at the time of laminating is either 0.1 MPa, 0.2 MPa, 0.4 MPa, 0.7 MPa, or 1.0 MPa. Moreover, the temperature of the resin layer in the case of lamination is either 60 degreeC, 90 degreeC, 120 degreeC, or 150 degreeC. The time for applying pressure (pressing time) was 30 seconds.

[9. Step (E)]
The resin layer in the laminate obtained in the step (D) was cooled to room temperature (25 ° C.), and the PET support as a temporary support was peeled from the laminate. In the obtained laminate, a resin layer was deposited only on the insulating layer.
In addition, after this process, a surface inspection was performed with an optical microscope, and it was inspected whether there was a transfer defect of the sheet product or a resin layer in a portion overlapping with the via hole was not cut out. In the inspection, only the sample having no problem was subjected to the following steps.

[10. Step (K)]
A UV exposure machine (model number: UVF-502S, lamp: UXM-501MD) manufactured by Mitsunaga Electric was used for the obtained laminate, and an irradiation power of 1.5 mW / cm ² (ultraviolet integrated light meter manufactured by Ushio Electric Co., Ltd.). The irradiation polymer was irradiated with UV light of 254 nm at 500 mJ using a UIT150-light receiving sensor UVD-S254, and a graft polymer was formed on the entire surface of the insulating layer. Next, the obtained laminate was immersed in stirred acetone for 5 minutes, and then washed with distilled water.
As described above, a resin layer chemically bonded directly to the insulating layer was formed.

[11. Step (F)]
A palladium catalyst comprising 40 parts by mass of diethylene glycol diethyl ether (manufactured by Wako Pure Chemical Industries, Ltd.), 40 parts by mass of water, 20 parts by mass of nitric acid (manufactured by Wako Pure Chemical Industries, Ltd.) and 0.25 parts by mass of palladium acetate (manufactured by Wako Pure Chemical Industries, Ltd.) A solution was prepared, and the laminate obtained in step (K) was immersed in this palladium catalyst solution for 5 minutes, and then washed with water.
As described above, an electroless plating bath having the following composition using Sulcup PGT (PGT-A, PGT-B, PGT-C) manufactured by Uemura Kogyo Co., Ltd. is used for the laminate provided with the plating catalyst. Electroless plating was performed at an electroless plating temperature of 26 ° C. for 30 minutes. The thickness of the obtained electroless copper plating film was 0.5 μm both on the resin layer, on the side surface of the via hole, and on the bottom.
The raw materials for the electroless plating solution are as follows.
・ Distilled water 79.2 mass%
・ PGT-A 9.0% by mass
-PGT-B 6.0 mass%
-PGT-C 3.5% by mass
-Formalin (Wako Pure Chemicals: formaldehyde solution) 2.3% by mass

  The obtained laminate with electroless copper plating film was subjected to heat treatment at 150 ° C. for 30 minutes, and then degreased with 10% sulfuric acid to drop the heat-treated oxide film.

An electroplating solution was prepared with the following raw material composition using CU-BRITE VFII-A and CU-BRITE VFII-B manufactured by EBARA Eugene Light, and a laminate to which electroless copper plating was applied using the electroplating solution On the other hand, electroplating for 40 minutes was performed. The current value at the time of electroplating was 0.3 A / dm ^2. The thickness of the obtained electrolytic copper plating film was 25 μm on the insulating film and 50 μm on the bottom of the via hole.
・ Distilled water 80.20% by mass
・ Copper sulfate pentahydrate (Wako Pure Chemical Industries) 16.06% by mass
・ Concentrated sulfuric acid 2.01% by mass
・ VFII-A 1.64% by mass
・ VFII-B 0.08% by mass
・ HCl 0.01% by mass

  Through the above process, a multilayer wiring board having filled vias in which the layers were electrically connected was produced.

  The above process (Y) to process (W) are performed again on the obtained copper thin film on the multilayer wiring board, and a via chain in which 100 50 μmφ blind vias as shown in FIG. 8A are connected. (Via hole daisy chain) 10 units were formed. FIG. 8A is a schematic cross-sectional view showing the via chain obtained in the first embodiment.

<Example 2>
A multilayer wiring board and a via chain were produced in the same manner as in Example 1 except that the thickness of the resin layer was changed from 0.5 μm to 2.5 μm in the step (D).
A schematic cross-sectional view of the via chain obtained in Example 2 is shown in FIG.

<Example 3>
The same method as in Example 1 except that in the step (D), the polymer B was used instead of the polymer A, and in the step (F), a 0.5 mass% silver nitrate aqueous solution was used instead of the palladium catalyst solution. Thus, a multilayer wiring board and a via chain were produced.
A schematic cross-sectional view of the via chain obtained in Example 3 is shown in FIG.

<Example 4>
Before the step (D) of Example 1, the following step (G) and step (H) are carried out, and then the laminated body provided with the obtained adhesion auxiliary layer is the step of Example 1. Steps (F) to (F) were carried out to produce a multilayer wiring board and a via chain having an adhesion auxiliary layer and a resin layer.
FIG. 8B is a schematic cross-sectional view showing the via chain obtained in Example 4, and includes an adhesion auxiliary layer as compared with FIG. 8A.

[Step (G)]
First, the adhesion auxiliary layer forming laminated film used in the step (G) was produced by the following method.

(Insulating composition containing a polymerization initiator)
20 parts by mass of bisphenol A type epoxy resin (epoxy equivalent 185, Epicoat 828 manufactured by Yuka Shell Epoxy Co., Ltd.), cresol novolac type epoxy resin (epoxy equivalent 215, Epiklon N-673 manufactured by Dainippon Ink & Chemicals, Inc.) 45 20 parts by mass of phenol novolac resin (phenolic hydroxyl group equivalent 105, phenolite manufactured by Dainippon Ink & Chemicals, Inc.) in 20 parts by mass of ethyl diglycol acetate and 20 parts of solvent naphtha are heated and dissolved with stirring. After cooling to room temperature, 30 parts by mass of cyclohexanone varnish (YL6747H30 manufactured by Yuka Shell Epoxy Co., Ltd., nonvolatile content 30 mass%, weight average molecular weight 47000) of phenoxy resin composed of Epicoat 828 and bisphenol S, 2-phenyl -4,5-bi 0.8 parts by mass of (hydroxymethyl) imidazole, 2 parts by mass of finely pulverized silica, and 0.5 parts by mass of a silicon-based antifoaming agent (trade name: KS604, manufactured by Shin-Etsu Silicon Co., Ltd.) are added to the mixture. 10 parts of the polymerization initiator (polymerization initiating polymer P) synthesized by the above method was added to obtain an insulating composition containing the polymerization initiator.

(Synthesis of polymerization initiating polymer P)
30 g of propylene glycol monomethyl ether (MFG) was added to a 300 ml three-necked flask and heated to 75 ° C. [2- (Acryloyloxy) ethyl] (4-benzoylbenzyl) dimethyl ammonium bromide (8.1 g), 2-hydroxyethylmethacrylate (9.9 g), isopropylmethaacrylate (13.5 g), dimethyl-2,2 ′ -A solution of 0.43 g of azobis (2-methylpropionate) and 30 g of MFG was added dropwise over 2.5 hours. Thereafter, the reaction temperature was raised to 80 ° C., and the reaction was further continued for 2 hours to obtain a polymer P having a polymerization initiating group.

(Dispersion of silica fine particles)
10 weights of MEK-dispersed silica sol (trade name: MEK-ST-L, SiO ₂ 20 wt%, particle size 70-100 nm, manufactured by Nissan Chemical Industries, Ltd.) is added to 100 parts by weight of the insulating composition containing the polymerization initiator. Part of the mixture was added and mixed and stirred at 25 ° C. for 30 to prepare a coating solution.

The prepared coating solution is applied by spin coating onto a PET support having a film thickness of 32 μm by a spin coating method, dried at 80 ° C. for 20 minutes, and provided with an adhesion auxiliary layer having a thickness of 1.5 μm. A laminated film for forming an auxiliary layer was obtained.
The obtained laminated film was laminated on the insulating layer having the via hole obtained in the step (C) while applying a predetermined pressure (pressing) to obtain a laminated body. The pressure condition at the time of laminating is either 0.1 MPa, 0.2 MPa, 0.4 MPa, 0.7 MPa, or 1.0 MPa. Further, the temperature of the adhesion auxiliary layer at the time of laminating is either 60 ° C., 90 ° C., 120 ° C., or 150 ° C. The time for applying pressure (pressing time) was 30 seconds.

[Step (H)]
The adhesion auxiliary layer in the laminate obtained in the step (G) was cooled to room temperature (25 ° C.), and the PET support as a temporary support was peeled from the laminate. In the obtained laminate, the adhesion auxiliary layer was deposited only on the insulating layer.
After the step, a surface inspection was performed with an optical microscope, and it was inspected whether there was a transfer defect of the sheet product or whether the adhesion assisting layer in the portion overlapping with the via hole was cut out. In the inspection, only the sample having no problem was subjected to the step (D).

<Comparative Example 1>
Using the materials used in Example 1 described in paragraphs [0121] to [0133] of JP 2010-157590 A, the method described in Example 1 is the same as in Examples 1 to 3 above. A multilayer wiring board having a structure was prepared.
Further, steps (Y) to (W) are performed on the obtained multilayer wiring board in the same manner as in Examples 1 to 3, and 100 blind vias of 50 μmφ as shown in FIG. 8A are connected. 10 units of via chains were formed.

<Stripping strength of surface copper foil (metal layer) (90 ° peel strength)>
For the via substrate (laminated body) obtained in Examples 1 to 4 and Comparative Example 1, the surface copper foil was coated by the method described in JIS C 6481 (1996) copper-clad laminate test for printed wiring boards. A 90 ° peel test was performed. The test machine used Autograph AGS-J made by Shimadzu Corporation, the width of the copper foil to be peeled off was 10 mm, the peeling speed was 50 mm per minute, the number of measurements was N = 5, and the average value was calculated. . Although the average value was computed, all of Examples 1-4 and the comparative example 1 showed the practical value with 0.7-0.8 N / mm.
From a practical point of view, the peel strength needs to be 0.6 N / mm or more.

<Evaluation of film properties (part 1)>
The resin layer (hereinafter referred to as resin layer A) composed of the polymer A used above, the resin layer composed of polymer B (hereinafter referred to as resin layer B as appropriate), and the Young's modulus (storage elastic modulus) of the adhesion auxiliary layer It measured with the frequency of 1 Hz with the dynamic viscoelasticity measuring apparatus (DMS6100, product made from SII).
The glass transition temperature of the resin layer A is 35 ° C., and the Young's modulus in the temperature range of glass transition temperature to glass transition temperature + 60 ° C. is 2.0 × 10 ^{5 to} 6.0 × 10 ⁷ MPa, and the breaking point The elongation was 70%.
The glass transition temperature of the resin layer B is 75 ° C., and the Young's modulus in the temperature range of glass transition temperature to glass transition temperature + 60 ° C. is 5.0 × 10 ^{5 to} 1.0 × 10 ⁸ MPa, and the breaking point The elongation was 25%.
The glass transition temperature of the adhesion auxiliary layer is 105 ° C., the Young's modulus in the temperature range of glass transition temperature to glass transition temperature + 60 ° C. is 8.0 × 10 ^{5 to} 1.0 × 10 ⁸ MPa, and the breaking point. The elongation was 15%.

<Evaluation of film properties (2)>
In Examples 1 and 2, the interfacial peel strength σ (A1) per unit area between the resin layer A and the insulating layer, the interfacial peel strength σ (B1) per unit area between the resin layer A and the temporary support, and the resin The breaking stress σ (C1) of the layer A was measured by Cycus (manufactured by Mekong Co., Ltd.).
The interfacial peel strength σ (A1) is 200 MPa, the interfacial peel strength σ (B1) is 140 MPa, the breaking stress σ (C1) is 75 MPa, and the relationship of σ (A1)> σ (B1)> σ (C1) is satisfied. I met.
In Example 3, the interfacial peel strength σ (A1) per unit area between the resin layer B and the insulating layer is 220 MPa, and the interfacial peel strength σ (B1) per unit area between the resin layer B and the temporary support is 160 MPa. The breaking stress σ (C1) of the resin layer B was 100 MPa, and the relationship of σ (A1)> σ (B1)> σ (C1) was satisfied.
In Example 4, the interfacial peel strength σ (A2) per unit area of the adhesion auxiliary layer and the insulating layer is 180 MPa, and the interfacial peel strength σ (B2) per unit area of the adhesion auxiliary layer and the temporary support is 130 MPa, The breaking stress σ (C2) of the adhesion auxiliary layer was 80 MPa, and the relationship of σ (A2)> σ (B2)> σ (C2) was satisfied.
In Example 4, the interfacial peel strength σ (A3) per unit area between the resin layer A and the adhesion auxiliary layer is 180 MPa, and the interfacial peel strength σ (B1) per unit area between the resin layer A and the temporary support. Is 130 MPa, the breaking stress σ (C1) of the resin layer A is 80 MPa, and σ (A2), σ (A3)> σ (B1), σ (B2)> σ (C1), σ (C2) Was met.

<Formability of laminate after peeling temporary support>
About Example 1 to Example 4, the yield of the unnecessary area cut-off removal of the sheet that overlaps the via hole after the temporary support peeling in the step (D) or the step (H) is obtained as a resin layer A, a resin layer B, Each adhesion auxiliary layer was examined.
Specifically, as shown in the Examples, lamination of each laminated film was performed under a total of 20 conditions of a combination of 4 temperatures and 5 press points. The number of inspected via holes was 441 each, and the inspection was performed by observing the surface of the laminate after peeling off the temporary support with an electron microscope. After laminating each laminated film and peeling off the temporary support, the number of via holes remaining without being blocked by the resin layer A, the resin layer B, or the adhesion auxiliary layer is counted, and the cut-off removal rate ( The remaining via hole / 441) was calculated. The higher the cutout removal rate, the more via holes remain.
The one with a cut-off removal rate of 100% is judged as ◯, the one with 20% or more but less than 100% is judged as △, the one with less than 20% is judged as ×, the Young's modulus (storage modulus) of the sheet product at the laminating temperature, Mapping was done for. The results of Examples 1 to 4 are shown in Table 1, and the mapping results are shown in Table 7. In practice, it is necessary to be “◯”. In addition, the result of Example 4 in Table 1 is a result of measuring the cut-off removal rate of the adhesion auxiliary layer using the laminated film for forming the adhesion auxiliary layer. The result of the cutout removal rate of the resin layer in Example 4 was the same as that in Example 1.
Further, FIG. 4 shows an SEM photograph of an OK product (via holes remain) and FIG. 5 and FIG. 6 show an SEM photograph of an NG product (via holes blocked by various layers). FIG. 5 shows a case where a part of each layer remains, and FIG. 6 shows a case where the via hole is blocked by each layer.

From the mapping result, it was found that the via hole was well formed in the thick line frame shown in FIG. The stress-strain characteristics were calculated by finite element analysis, but similar results were obtained. Based on the results of mapping and stress analysis, the result of linear approximation of the frame line,
i) P = 0.3 × 10 ⁶ Log (E (T)) − 1.4 × 10 ⁶
ii) P = 0.06 × 10 ⁶ Log (E (T)) − 0.3 × 10 ⁶
iii) Log (E (T)) = 5.2
iv) Log (E (T)) = 8
It can be seen that the area enclosed by i) to iv) is an area where via holes can be formed (area where sheets can be cut out), and if the Young's modulus of the sheet and the pressure (pressing) during lamination are managed, It was found that the formation of can be controlled.

<Comparative example 2>
[8. In the step (D)], the multilayer wiring board and the via chain were prepared in the same procedure as in Example 1 except that the pressure condition at the time of lamination was 0.15 MPa and the temperature of the resin layer was 110 ° C. It was.
However, in Comparative Example 2, the cut-off removal rate after peeling off the temporary support was “x”, and a desired multilayer wiring board could not be obtained.

<Initial conductivity of via chain>
In order to evaluate the connection reliability of the via chains produced in Examples 1 to 4 and Comparative Example 1, the conduction failure rate (initial failure) immediately after the formation of the wiring was examined. Here, what did not conduct | electrically_connected was judged as a conduction | electrical_connection defect. The results are shown in Table 2 below. In Examples 1 to 4, the evaluation was made on the via chains manufactured under the conditions 1 to 5 in Table 2.
In Table 2, the temperature (T) means the temperature of the resin layer or the adhesion auxiliary layer during lamination, and the pressure (P) means the pressure applied to the resin layer forming laminated film or the adhesion auxiliary layer forming laminated film. To do. In practice, the conduction failure rate is desirably 30% or less. In Example 4 in Table 2, the cutout removal rate of the resin layer A and the adhesion auxiliary layer was 100%.
It was found that vias formed by the manufacturing method of the present invention have very good via chain conduction compared to the comparative example.
On the other hand, when the defective conduction of the failed product of the comparative example was examined, it was found that many filling defects as shown in the SEM photograph of FIG. 9 occurred frequently. In the comparative example, it was found from the SEM photograph that the plating growth from the wall surface was low or unstable. This can be expected to be caused by forming the resin layer using the liquid composition.

10: Wiring substrate 12: Substrate 14: Metal wiring 16: Insulating layer 18: Via hole 20: Resin layer 22: Temporary support 24: Laminate film 26, 34, 36 for resin layer formation: Laminate 28: Metal film 30: Adhesion Auxiliary layer 32: laminated film for adhesion auxiliary layer

Claims (10)

(A) a step of forming an insulating layer on the surface of a wiring board provided with a metal wiring; (B) a step of forming a via hole so as to penetrate the insulating layer and reach the metal wiring;
(C) a step of performing a desmear treatment after the step (B);
(D) After the step (C), a temporary support, a functional group that forms an interaction with the plating catalyst or its precursor on the temporary support, and a resin layer containing a polymer containing a polymerizable group; Laminating a laminated film for forming a resin layer on the insulating layer so that the resin layer and the insulating layer subjected to desmear treatment are in contact with each other, and obtaining a laminated body;
(E) After the step (D), a step of peeling the temporary support from the laminate,
(F) After the step (E), a plating catalyst or a precursor thereof is applied to the wall surface of the via hole and the resin layer, and plating is performed.
In the step (D), the temperature T of the resin layer when laminating is not less than the glass transition temperature of the resin layer and not more than the glass transition temperature + 60 ° C., and the Young's modulus E (T) of the resin layer at the temperature T Is 0.16 × 10 ^{6 to} 100 × 10 ⁶ Pa, and the elongation at break of the resin layer is 100% or less,
When laminating the laminated film for resin layer formation, the pressure P applied to the laminated film for resin layer formation and Log (E (T)) are represented by the following formulas (I) to (I) shown in FIG. A manufacturing method of a multilayer wiring board existing in a range surrounded by a straight line represented by IV).
Formula (I) Log (E (T)) = 5.2
Formula (II) Log (E (T)) = 8
Formula (III) P = 0.3 × 10 ⁶ (Log (E (T)) − 1.4 × 10 ⁶
Formula (IV) P = 0.06 × 10 ⁶ (Log (E (T)) − 0.3 × 10 ⁶ In the step (E), the temperature of the resin layer is 0 to 40 ° C.
Interfacial peel strength σ (A1) per unit area between the resin layer and the insulating layer, interfacial peel strength σ (B1) per unit area between the resin layer and the temporary support, and fracture of the resin layer The method for manufacturing a multilayer wiring board according to claim 1, wherein the stress σ (C1) satisfies the following relationship.
σ (A1)> σ (B1)> σ (C1)   The manufacturing method of the multilayer wiring board of Claim 1 or 2 whose thickness of the said resin layer is 0.05-3.0 micrometers.   The manufacturing method of the multilayer wiring board in any one of Claims 1-3 provided with the process of giving energy with respect to the said resin layer between the said process (E) and the said process (F). The manufacturing method of the multilayer wiring board according to claim 1, wherein the following steps (G) to (J) are performed in this order instead of the step (D) and the step (E).
(G) After the step (C), the adhesion auxiliary layer forming laminated film provided with the temporary support and the adhesion auxiliary layer on the temporary support, and the adhesion auxiliary layer and the desmear treatment on the insulating layer. Laminating the applied insulating layer so as to be in contact with each other and obtaining a laminated body (H) After the step (G), the step of peeling the temporary support from the laminated body (I) After the step (H) A laminated film for forming a resin layer, comprising: a temporary support; and a resin layer containing a polymer containing a polymerizable group and a functional group that forms an interaction with the plating catalyst or a precursor thereof on the temporary support. The step (J) of obtaining a laminate by laminating the resin layer and the adhesion auxiliary layer in contact with the adhesion auxiliary layer (J) After the step (I), peeling the temporary support from the laminate. Process In addition, the said process (G) and the said process ( In I), the temperature T of the adhesion assisting layer and the resin layer when laminating is not less than the glass transition temperature of each of the adhesion assisting layer and the resin layer and not more than the glass transition temperature + 60 ° C., and the temperature T The Young's modulus E (T) of the adhesion auxiliary layer and the resin layer is 0.16 × 10 ^{6 to} 100 × 10 ⁶ Pa, and the elongation at break of the adhesion auxiliary layer and the resin layer is 100% or less,
When laminating the laminated film for forming an adhesion auxiliary layer and the laminated film for forming a resin layer, a pressure P applied to the laminated film for forming an adhesion auxiliary layer and the laminated film for forming a resin layer, and Log (E (T )) Exists in a range surrounded by a straight line represented by the following formulas (I) to (IV) shown in FIG.
Formula (I) Log (E (T)) = 5.2
Formula (II) Log (E (T)) = 8
Formula (III) P = 0.3 × 10 ⁶ (Log (E (T)) − 1.4 × 10 ⁶
Formula (IV) P = 0.06 × 10 ⁶ (Log (E (T)) − 0.3 × 10 ⁶   The manufacturing method of the multilayer wiring board of Claim 5 provided with the process of giving energy with respect to the said resin layer between the said process (J) and the said process (F).   The method for producing a multilayer wiring board according to claim 5, wherein the adhesion auxiliary layer contains a polymerization initiator.   The manufacturing method of the multilayer wiring board in any one of Claims 1-7 whose said plating catalyst or its precursor is a compound containing Pd, Ag, or Cu.   The manufacturing method of the multilayer wiring board in any one of Claims 1-8 whose functional group which forms an interaction with the said plating catalyst or its precursor is a cyano group or a carboxylic acid group. The multilayer wiring board obtained by the manufacturing method of the multilayer wiring board in any one of Claims 1-9.