JP2014229775A - Printed wiring board, semiconductor package, semiconductor device and printed wiring board manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a printed wiring board excellent in insulation reliability between interconnections.SOLUTION: A printed wiring board 100 comprises an insulation layer 103 having a via hole 101 and a circuit layer 105 provided at least on one surface 110 of the insulation layer 103. In the printed wiring board 100, an average of a ratio of a chrome content to a carbon content at a peripheral region C1 of the via hole 101 on the one surface 110 of the insulation layer 103, which are measured by X-ray photoemission spectroscopy is not higher than 0.090, and ten point mean roughness Rz of the one surface 110 of the insulation layer 103, which is measured in conformity to JIS B0601:2001 is not lower than 1.2 μm.

Description

  The present invention relates to a printed wiring board, a semiconductor package, a semiconductor device, and a method for manufacturing a printed wiring board.

  In recent years, along with the demand for higher functionality of electronic devices, higher density integration of electronic components and further higher density mounting have progressed, and printed wiring boards used for these are smaller and thinner than before. , Higher density, and multi-layering are progressing. Accordingly, there is a need for a printed wiring board that can be thinned and that can form high-density and fine circuits.

  As a method for forming a fine circuit, an SAP (semi-additive process) method has been proposed. In the SAP method, first, a roughening treatment is performed on the surface of the insulating layer, and an electroless metal plating film serving as a base is formed on the surface of the insulating layer. Next, the non-circuit forming portion is protected by the plating resist, and the copper thickness of the circuit forming portion is thickened by electrolytic plating. Thereafter, the plating resist is removed, and the electroless metal plating film other than the circuit forming portion is removed by flash etching, thereby forming a circuit on the insulating layer. In the SAP method, since the metal layer laminated on the insulating layer can be thinned, finer circuit wiring is possible.

  However, the conventional insulating layer has a problem that the electroless plating property is poor and the SAP method cannot be performed well. Then, the method of using the metal-clad laminated board which laminated | stacked the roughening metal foil with a primer layer on the insulating layer is proposed (for example, patent document 1, 2). In this method, the surface of the primer layer obtained by removing the non-roughened metal foil on the metal-clad laminate is formed with a circuit without performing a roughening treatment, thereby improving the electroless plating property of the insulating layer surface. It has improved. Patent Literature 1 and Patent Literature 2 disclose a metal-clad laminate in which a specific polyimide resin layer is disposed between a metal foil and an insulating layer.

JP 2006-196863 A JP 2007-326962 A

  However, according to the study by the present inventors, it has become clear that the printed wiring board obtained by the method using the above-described metal-clad laminate is inferior in insulation reliability between wirings.

  Accordingly, an object of the present invention is to provide a printed wiring board having excellent insulation reliability between wirings.

  The present inventors diligently investigated the factors that cause the printed wiring board obtained by the above-described method using a metal-clad laminate to be inferior in insulation reliability between wirings. As a result, when the metal layer is removed from the metal-clad laminate, part of the metal layer remains on the surface of the insulating layer, and the metal component contained in the remaining metal layer is a factor that reduces the insulation reliability between the wirings. I found out that it was one.

  Therefore, the present inventors have intensively studied the insulation reliability between the wirings while adjusting the amount of the metal component on the surface of the insulating layer by chemical treatment or plasma treatment. As a result, by reducing the amount of the metal component on the surface of the insulating layer, the insulation reliability between the wirings may be improved to some extent, while the adhesion between the insulating layer and the circuit layer deteriorates, and the wiring It has become clear that the insulation reliability of the case may deteriorate. That is, the present inventors have clarified that the insulation reliability between the wirings cannot be improved only by reducing the amount of the metal component on the surface of the insulating layer.

  Therefore, the present inventors conducted further intensive studies. As a result, the inventors have found that a printed wiring board having excellent insulation reliability between wirings can be obtained by setting the chromium amount and surface roughness on the surface of the insulating layer within a specific range, thereby completing the present invention.

That is, according to the present invention,
A printed wiring board having an insulating layer having a via hole and a circuit layer provided on at least one surface of the insulating layer,
The average value of the ratio of the chromium amount to the carbon amount measured by X-ray photoelectron spectroscopy in the peripheral region of the via hole on the one surface is 0.090 or less,
Provided is a printed wiring board having a 10-point average roughness Rz of 1.2 μm or more measured on the basis of JIS B0601: 2001.

  Furthermore, according to the present invention, there is provided a semiconductor package in which a semiconductor element is mounted on the printed wiring board.

  Furthermore, according to the present invention, a semiconductor device is provided in which the semiconductor package is mounted on a mounting substrate.

Furthermore, according to the present invention, a manufacturing method for manufacturing the printed wiring board,
Forming a via hole in a metal-clad laminate in which a metal layer is laminated on at least one surface of the insulating layer;
A step of removing the metal layer by an etching process;
By chemical treatment or plasma treatment, the average value of the ratio of the chromium amount to the carbon amount measured by X-ray photoelectron spectroscopy in the peripheral region of the via hole on the one surface is reduced to 0.090 or less, and JIS B0601 : A step of measuring 10-point average roughness Rz of the one surface, which is measured according to 2001, to 1.2 μm or more;
A method for manufacturing a printed wiring board is provided.

  ADVANTAGE OF THE INVENTION According to this invention, the printed wiring board excellent in the insulation reliability between wiring can be provided.

It is sectional drawing which shows an example of a structure of the printed wiring board of embodiment which concerns on this invention. It is sectional drawing for demonstrating the measurement area | region of ratio of chromium amount with respect to carbon amount. It is sectional drawing which shows an example of a structure of the semiconductor package of embodiment which concerns on this invention. It is sectional drawing which shows an example of a structure of the semiconductor device of embodiment which concerns on this invention. It is sectional drawing which showed typically an example of the manufacturing method of the printed wiring board of embodiment which concerns on this invention. It is sectional drawing which shows an example of a structure of the printed wiring board of embodiment which concerns on this invention. It is sectional drawing which shows an example of a structure of the semiconductor package of embodiment which concerns on this invention. It is sectional drawing which shows an example of a structure of the semiconductor device of embodiment which concerns on this invention.

  Embodiments of the present invention will be described below with reference to the drawings. In all the drawings, similar constituent elements are denoted by common reference numerals, and description thereof is omitted as appropriate. Moreover, the figure is a schematic diagram and does not necessarily match the actual dimensional ratio.

[Printed wiring board]
First, the configuration of the printed wiring board according to the present embodiment will be described. FIG. 1 is a cross-sectional view showing an example of the configuration of a printed wiring board 100 according to an embodiment of the present invention. FIG. 2 is a cross-sectional view for explaining a measurement region of the ratio of the chromium amount to the carbon amount.

  The printed wiring board 100 according to this embodiment includes an insulating layer 103 having a via hole 101 and a circuit layer 105 provided on at least one surface 110 of the insulating layer 103.

And the printed wiring board 100 which concerns on this embodiment WHEREIN: The average value (henceforth the ratio of chromium amount with respect to the carbon amount measured by X-ray photoelectron spectroscopy in the peripheral region C1 of the via hole 101 of the one surface 110 of the insulating layer 103). , Also simply referred to as the ratio of chromium to carbon) is 0.090 or less, preferably 0.080 or less, more preferably 0.075 or less. When the average value is equal to or less than the upper limit value, the electroless plating property of the insulating layer 103 is improved, and a uniform electroless metal plating film can be formed on the surface of the insulating layer 103. As a result, the fine wiring processability of the electroless metal plating film is improved, and the high-quality circuit layer 105 can be formed, so that the insulation reliability between the wirings of the printed wiring board 100 can be improved. Moreover, since the average value is equal to or less than the upper limit value, ion migration of the metal component existing on the surface of the insulating layer 103 can be suppressed, so that the insulation reliability between the wirings of the printed wiring board 100 can be improved.
Although it does not specifically limit about the lower limit of the said average value, 0.000 is preferable and it is 0.001 or more normally.

Here, the peripheral area C1 of the via hole 101 on one surface 110 is, for example, 100 μm in the in-plane direction from the peripheral edge 107 of the via hole 101 and in the thickness direction from one surface 110 of the insulating layer 103 as shown in FIG. An area of 5 nm is shown. In this embodiment, the average value of the ratio of the chromium amount to the carbon amount measured by X-ray photoelectron spectroscopy represents an index of the amount of the metal component on the surface of the insulating layer 103 in contact with the circuit layer 105. That is, the higher the average value, the more metal components are present on one surface 110 of the insulating layer 103 in contact with the circuit layer 105. The ratio of the chromium amount to the carbon amount is a molar ratio.
In the present embodiment, the via hole 101 is a hole for electrically connecting layers, and may be either a through hole or a non-through hole.
In the present embodiment, when there are a plurality of via holes 101, the ratio of the chromium amount to the carbon amount in the peripheral region C1 of at least one via hole 101 only needs to satisfy the above range, and the carbon amount in the peripheral region C1 of all the via holes 101 It is preferable that the ratio of the chromium amount to the above satisfies the above range.

  In the printed wiring board 100 according to the present embodiment, the 10-point average roughness Rz of one surface 110 of the insulating layer 103, which is measured in accordance with JIS B0601: 2001, is 1.2 μm or more, preferably It is 1.3 μm or more, more preferably 1.5 μm or more. When Rz is equal to or greater than the lower limit, adhesion between the insulating layer 103 and the circuit layer 105 is improved, and peeling of the circuit layer 105 can be suppressed. As a result, the insulation reliability between the wirings of the printed wiring board 100 can be improved. The upper limit of Rz is not particularly limited, but is usually 4.0 μm or less.

  In the printed wiring board 100 according to the present embodiment, the peel strength between the insulating layer 103 and the circuit layer 105, which is measured in accordance with JIS C-6481: 1996, is preferably 0.5 kN / m or more. More preferably, it is 0.6 kN / m or more. When the peel strength is equal to or higher than the lower limit, peeling of the circuit layer 105 can be further suppressed, and as a result, the insulation reliability between the wirings of the printed wiring board 100 can be further improved.

  FIG. 5 is a cross-sectional view schematically showing an example of a method for manufacturing the printed wiring board 100 according to the embodiment of the present invention. The printed wiring board 100 according to the present embodiment is obtained, for example, by processing a metal-clad laminate 200 in which a metal layer 203 is laminated on at least one surface 110 of the insulating layer 103. Since the surface of the metal layer 203 is chromated, the metal layer 203 contains chromium as an essential component. Although details will be described later, the metal layer 203 is removed from the metal-clad laminate 200 in the manufacturing process of the printed wiring board 100 according to the present embodiment. At that time, a part of the metal layer 203 remains on the surface of the insulating layer 103. Therefore, chromium contained in the metal layer 203 exists on one surface 110 of the insulating layer 103 according to the present embodiment. In this embodiment, the amount of chromium is controlled.

  As shown in FIG. 1, the printed wiring board 100 according to the present embodiment may be a single-sided printed wiring board, a double-sided printed wiring board, or a multilayer printed wiring board. The double-sided printed wiring board is a printed wiring board in which circuit layers are laminated on both sides of the insulating layer 103. The multilayer printed wiring board is a printed wiring board in which three or more circuit layers are laminated on the insulating layer 103 via an interlayer insulating layer by a plated through hole method, a build-up method, or the like.

<Circuit layer>
The circuit layer 105 according to the present embodiment includes, for example, an electroless metal plating film 108 and an electrolytic metal plating layer 109.

  The circuit layer 105 is formed by, for example, the SAP method on the surface of the primer layer 113 that has been subjected to chemical treatment or plasma treatment. FIG. 5 is a cross-sectional view schematically showing an example of a method for manufacturing the printed wiring board 100 according to the embodiment of the present invention. After the electroless plating process is performed on the primer layer 113 (FIG. 5E), the non-circuit forming portion is protected by the plating resist 201, and the electrolytic metal plating layer 109 is applied by electrolytic plating (FIG. 5F). The circuit layer 105 is formed on the primer layer 113 by removing the plating resist 201 and removing the electroless metal plating film 108 by flash etching (FIG. 5G).

  The circuit dimension of the circuit layer 105, when expressed in line and space (L / S), can be 25 μm / 25 μm or less, particularly 15 μm / 15 μm or less. If the circuit dimensions are reduced and the wiring is made fine, the adhesiveness decreases and the insulation reliability between the wirings decreases. However, the printed wiring board 100 according to the present embodiment is capable of fine wiring with a line and space (L / S) of 15 μm / 15 μm or less, and the line and space (L / S) can be refined to about 10 μm / 10 μm. Can be achieved.

  The thickness of the circuit layer 105 according to the present embodiment is not particularly limited, but is usually 5 μm or more and 25 μm or less.

<Insulating layer>
The insulating layer 103 according to the present embodiment includes, for example, a core layer 111, a primer layer 113, and a via hole 101. In addition, the insulating layer 103 according to the present embodiment may further include a buildup layer 115 as shown in FIG.

  The thickness of the insulating layer 103 according to this embodiment is preferably 0.025 mm to 0.6 mm, more preferably 0.04 mm to 0.4 mm, and further preferably 0.04 mm to 0.3 mm. Or less, particularly preferably 0.05 mm or more and 0.2 mm or less. When the thickness of the insulating layer 103 according to this embodiment is within the above range, the balance between mechanical strength and productivity is particularly excellent, and the insulating layer 103 suitable for a thin printed wiring board can be obtained.

<Primer layer>
As shown in FIG. 1, the primer layer 113 is interposed between the core layer 111 and the circuit layer 105, and is formed of, for example, a primer resin composition P containing a thermosetting resin and an inorganic filler. .
In addition, when the primer layer 113 further includes a buildup layer 115 as shown in FIG. 6, the buildup layer 115 and the circuit layer 120 (for example, the electroless metal plating film 118) are provided between the core layer 111 and the circuit layer 105. Between the core layer 111 and the circuit layer 105 and between the build-up layer 115 and the circuit layer 120 as shown in FIG. It is preferable to intervene between the two.
The thickness of the primer layer 113 is not particularly limited, but is usually 1 μm or more and 10 μm or less, preferably 2 μm or more and 8 μm or less. When the thickness of the primer layer 113 is within the above range, a printed wiring board corresponding to thinning can be obtained without losing the characteristics of the core layer 111. The thickness of the primer layer 113 is preferably not less than the above lower limit for improving the insulation reliability, and is preferably not more than the above upper limit for achieving a thin film which is one of the objects in the multilayer wiring board.

  The glass transition temperature (temperature increase rate 5 ° C./min, frequency 1 Hz) of the primer layer 113 measured by dynamic viscoelasticity is preferably 170 ° C. or higher and 300 ° C. or lower, more preferably 200 ° C. or higher and 260 ° C. or lower. In the present embodiment, the glass transition temperature can be measured using, for example, a dynamic viscoelasticity analyzer (DMA). When the glass transition temperature measured by dynamic viscoelasticity measurement of the primer layer 113 is within the above range, the resistance of the primer layer 113 to chemical treatment or plasma treatment can be further improved.

  The storage elastic modulus E ′ at 250 ° C. of the primer layer 113 measured at a frequency of 1 Hz is preferably 10 MPa or more and 350 MPa or less, more preferably 50 MPa or more and 300 MPa or less. In this embodiment, the storage elastic modulus E ′ is a storage elastic modulus measured at a temperature of 250 ° C. and a frequency of 1 Hz using a DMA device (DMA 2980 manufactured by TA Instruments). When the storage elastic modulus E ′ at 250 ° C. of the primer layer 113 is within the above range, the resistance of the primer layer 113 to chemical treatment or plasma treatment and the adhesion to the circuit layer can be further improved.

  The primer layer 113 preferably has a roughened surface on which the circuit layer 105 is formed. Concerning the adhesion between the primer layer 113 and the circuit layer 105, it is important to form irregularities on the surface of the primer layer 113 formed by roughening treatment. From the viewpoint of processability and reliability, the surface of the primer layer 113 is uniform and dense. It is desired to have a rough shape.

  A method for roughening the primer layer 113 is not particularly limited, and examples thereof include a method of performing a chemical treatment, a plasma treatment, or both surface treatments on the surface of the primer layer 113.

  The 10-point average roughness Rz on the surface of the primer layer 113 is preferably 1.2 μm or more, more preferably 1.3 μm or more, and further preferably 1.5 μm or more. When Rz is equal to or greater than the lower limit, adhesion between the primer layer 113 and the circuit layer 105 is improved, and peeling of the circuit layer 105 can be suppressed. As a result, the insulation reliability between the wirings of the printed wiring board 100 can be improved. The upper limit of Rz is not particularly limited, but is usually 4.0 μm or less.

Hereinafter, the primer resin composition P used for the primer layer 113 will be described.
The primer resin composition P preferably contains a thermosetting resin (A) and an inorganic filler (B).

(Thermosetting resin)
Although it does not specifically limit as a thermosetting resin (A), It has a low linear expansion coefficient and a high elastic modulus, and it is preferable that it is excellent in the reliability of thermal shock property.
The glass transition temperature of the thermosetting resin is preferably 160 ° C. or higher and 350 ° C. or lower, more preferably 180 ° C. or higher and 300 ° C. or lower. By using the thermosetting resin (A) having such a glass transition temperature, the resistance of the primer layer 113 to chemical treatment or plasma treatment can be improved. Moreover, the heat resistance of the printed wiring board can be improved.

Specific thermosetting resins (A) include, for example, novolak type phenol resins such as phenol novolak resin, cresol novolak resin, bisphenol A novolak resin; modified with unmodified resole phenol resin, tung oil, linseed oil, walnut oil, etc. Phenol resin such as resol type phenol resin such as modified oil-modified resole phenol resin; bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, bisphenol E type epoxy resin, bisphenol M type epoxy resin, bisphenol P type Bisphenol type epoxy resins such as epoxy resins and bisphenol Z type epoxy resins; Novolak type epoxy resins such as phenol novolac type epoxy resins and cresol novolak type epoxy resins Biphenyl type epoxy resin, biphenyl aralkyl type epoxy resin, aryl alkylene type epoxy resin, naphthalene type epoxy resin, anthracene type epoxy resin, phenoxy type epoxy resin, dicyclopentadiene type epoxy resin, norbornene type epoxy resin, adamantane type epoxy resin, fluorene Type epoxy resin and other epoxy resins; urea (urea) resins, melamine resins and other triazine ring resins; unsaturated polyester resins; bismaleimide resins; polyurethane resins; diallyl phthalate resins; silicone resins; Examples include cyanate resin; polyimide resin; polyamideimide resin; benzocyclobutene resin.
One of these may be used alone, two or more having different weight average molecular weights may be used in combination, and one or two or more thereof and a prepolymer thereof may be used in combination.

  The primer resin composition P preferably contains an epoxy resin as the thermosetting resin (A). Examples of the epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol E type epoxy resin, bisphenol S type epoxy resin, bisphenol M type epoxy resin, bisphenol P type epoxy resin, and bisphenol Z type epoxy resin. Bisphenol type epoxy resins; Novolak type epoxy resins such as phenol novolac type epoxy resins and cresol novolac type epoxy resins; Arylalkylene type epoxy resins such as biphenyl type epoxy resins, xylylene type epoxy resins and biphenyl aralkyl type epoxy resins; , Naphthalenediol type epoxy resin, bifunctional or tetrafunctional epoxy type naphthalene resin, naphthylene ether type epoxy resin, binaphthyl type Naphthalene type epoxy resins such as poxy resins and naphthalene aralkyl type epoxy resins; anthracene type epoxy resins; phenoxy type epoxy resins; dicyclopentadiene type epoxy resins; norbornene type epoxy resins; adamantane type epoxy resins; .

  As the epoxy resin, one of these may be used alone, two or more having different weight average molecular weights may be used in combination, and one or two or more thereof and a prepolymer thereof may be used in combination. May be.

  Among these epoxy resins, aryl alkylene type epoxy resins are particularly preferable. Thereby, the tolerance with respect to the chemical | medical solution process or plasma process of the primer layer 113 can be improved further.

  The aryl alkylene type epoxy resin refers to an epoxy resin having one or more aryl alkylene groups in a repeating unit. For example, a xylylene type epoxy resin, a biphenyl aralkyl type epoxy resin, etc. are mentioned. Among these, a biphenyl dimethylene type epoxy resin which is a kind of biphenyl aralkyl type epoxy resin is preferable. A biphenyl dimethylene type | mold epoxy resin can be shown with the following general formula (IV), for example.

  The average repeating unit n of the biphenyldimethylene type epoxy resin represented by the general formula (IV) is an arbitrary integer. Although the minimum of n is not specifically limited, 1 or more are preferable and 2 or more are more preferable. When n is not less than the above lower limit, crystallization of the biphenyldimethylene type epoxy resin can be suppressed and the solubility in a general-purpose solvent is improved, so that handling becomes easy. The upper limit of n is not particularly limited, but is preferably 10 or less, and more preferably 5 or less. When n is less than or equal to the above upper limit, the fluidity of the resin is improved and the occurrence of molding defects and the like can be suppressed.

  As the epoxy resin other than the above, a novolak type epoxy resin having a condensed ring aromatic hydrocarbon structure is preferable. Thereby, the tolerance with respect to the chemical | medical solution process or plasma process of the primer layer 113 can be improved further.

  The novolac type epoxy resin having a condensed ring aromatic hydrocarbon structure is a novolak type epoxy resin having a naphthalene, anthracene, phenanthrene, tetracene, chrysene, pyrene, triphenylene, tetraphen, or other condensed ring aromatic hydrocarbon structure. The novolac type epoxy resin having a condensed ring aromatic hydrocarbon structure is excellent in low thermal expansion because a plurality of aromatic rings can be regularly arranged. Moreover, since the glass transition temperature is also high, it is excellent in heat resistance. Furthermore, since the molecular weight of the repeating structure is large, it is superior in flame retardancy as compared with conventional novolac type epoxy resins, and the weakness of the weakness of the cyanate resin can be improved by combining with the cyanate resin. Therefore, when used in combination with a cyanate resin, the glass transition temperature is further increased, so that the lead-free compatible mounting reliability is excellent.

  The novolak-type epoxy resin having a condensed ring aromatic hydrocarbon structure is obtained by epoxidizing a novolak-type phenol resin synthesized from a phenol compound, a formaldehyde compound, and a condensed ring aromatic hydrocarbon compound.

  The phenol compound is not particularly limited, but examples thereof include cresols such as phenol, o-cresol, m-cresol, and p-cresol, 2,3-xylenol, 2,4-xylenol, 2,5-xylenol, 2, 6-xylenol, 3,4-xylenol, xylenols such as 3,5-xylenol, trimethylphenols such as 2,3,5 trimethylphenol, ethyl such as o-ethylphenol, m-ethylphenol, p-ethylphenol Phenols, alkylphenols such as isopropylphenol, butylphenol, t-butylphenol, o-phenylphenol, m-phenylphenol, p-phenylphenol, catechol, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene , Naphthalenediols such as 2,7-dihydroxynaphthalene, polyphenols such as resorcin, catechol, hydroquinone, pyrogallol and fluoroglucin, and alkyl polyphenols such as alkylresorcin, alkylcatechol and alkylhydroquinone. . Of these, phenol is preferable from the viewpoint of cost and the effect on the decomposition reaction.

  The aldehyde compound is not particularly limited, and examples thereof include formaldehyde, paraformaldehyde, trioxane, acetaldehyde, propionaldehyde, polyoxymethylene, chloral, hexamethylenetetramine, furfural, glyoxal, n-butyraldehyde, caproaldehyde, allylaldehyde, Examples include benzaldehyde, crotonaldehyde, acrolein, tetraoxymethylene, phenylacetaldehyde, o-tolualdehyde, salicylaldehyde, dihydroxybenzaldehyde, trihydroxybenzaldehyde, 4-hydroxy-3-methoxyaldehyde paraformaldehyde and the like.

  The condensed ring aromatic hydrocarbon compound is not particularly limited, and examples thereof include: naphthalene derivatives such as methoxynaphthalene and butoxynaphthalene; anthracene derivatives such as methoxyanthracene; phenanthrene derivatives such as methoxyphenanthrene; other tetracene derivatives; chrysene derivatives; A triphenylene derivative; a tetraphen derivative and the like.

  The novolak-type epoxy resin having a condensed ring aromatic hydrocarbon structure is not particularly limited. For example, methoxynaphthalene-modified orthocresol novolak epoxy resin, butoxynaphthalene-modified meta (para) cresol novolak epoxy resin, methoxynaphthalene-modified novolak epoxy resin, etc. Is mentioned. Among these, a novolac type epoxy resin having a condensed ring aromatic hydrocarbon structure represented by the following formula (V) is preferable.

(In the formula, Ar is a condensed ring aromatic hydrocarbon group. R may be the same or different from each other, and is a hydrogen atom, a hydrocarbon group having 1 to 10 carbon atoms, a halogen element, a phenyl group, A group selected from an aryl group such as a benzyl group and an organic group containing a glycidyl ether, n, p and q are integers of 1 or more, and the values of p and q may be the same for each repeating unit, May be different.)

(Ar in formula (V) is a structure represented by (Ar1) to (Ar4) in formula (VI). R in formula (VI) may be the same or different from each other. It is often a group selected from a hydrogen atom, a hydrocarbon group having 1 to 10 carbon atoms, an aryl group such as a halogen element, a phenyl group and a benzyl group, and an organic group including glycidyl ether.)

Further, as the epoxy resin other than the above, naphthalene type epoxy resins such as naphthol type epoxy resin, naphthalene diol type epoxy resin, bifunctional or tetrafunctional epoxy type naphthalene resin, naphthylene ether type epoxy resin and the like are preferable. Thereby, the tolerance with respect to the chemical | medical solution process or plasma process of the primer layer 113 can be improved further.
In addition, since the naphthalene ring has a higher π-π stacking effect than a benzene ring, it is particularly excellent in low thermal expansion and low thermal shrinkage. Furthermore, since the polycyclic structure has a high rigidity effect and the glass transition temperature is particularly high, the heat shrinkage change before and after reflow is small. As a naphthol type epoxy resin, for example, the following general formula (VII-1), as a naphthalene diol type epoxy resin, the following formula (VII-2), as a bifunctional or tetrafunctional epoxy type naphthalene resin, the following formula (VII-3): Examples of (VII-4) (VII-5) and naphthylene ether type epoxy resin can be represented by the following general formula (VII-6). Among these, naphthylene ether type epoxy resins are particularly preferable from the viewpoints of flame retardancy, heat resistance, high glass transition temperature, and low thermal expansion.

（ｎは平均１以上６以下の数を示し、Ｒはグリシジル基または炭素数１以上１０以下の炭化水素基を示す。）

(N represents an average number of 1 to 6, and R represents a glycidyl group or a hydrocarbon group having 1 to 10 carbon atoms.)

（式中、Ｒ^１は水素原子またはメチル基を表す。Ｒ^２はそれぞれ独立的に水素原子、炭素原子数１〜４のアルキル基、アラルキル基、ナフタレン基、またはグリシジルエーテル基含有ナフタレン基を表す。ｏおよびｍはそれぞれ０〜２の整数であって、かつｏまたはｍのいずれか一方は１以上である。）

(In the formula, R ¹ represents a hydrogen atom or a methyl group. R ² each independently represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an aralkyl group, a naphthalene group, or a glycidyl ether group-containing naphthalene group. O and m are each an integer of 0 to 2, and either o or m is 1 or more.)

  Although content of an epoxy resin is not specifically limited, 1 mass% or more is preferable with respect to the whole primer resin composition P, and 2 mass% or more is more preferable. When the content of the epoxy resin is not less than the above lower limit, the reactivity of the epoxy resin is improved, and the moisture resistance of the resulting product can be improved. Moreover, especially content of an epoxy resin is although it is not limited, 55 mass% or less is preferable with respect to the whole primer resin composition P, and 40 mass% or less is more preferable. Heat resistance can be improved more as content is below the said upper limit.

  Although the weight average molecular weight (Mw) of an epoxy resin is not specifically limited, Mw500 or more is preferable and especially Mw800 or more is preferable. When Mw is equal to or greater than the lower limit, it is possible to suppress the occurrence of tackiness in the primer layer 113. Mw is not particularly limited, but Mw is preferably 20,000 or less, and particularly preferably Mw15,000 or less. When Mw is not more than the above upper limit value, a more uniform primer layer 113 can be obtained. The Mw of the epoxy resin can be measured by GPC, for example.

The primer resin composition P may use a phenol resin or may be used in combination in addition to using an epoxy resin as the thermosetting resin (A).
Examples of the phenol resin include novolac type phenol resins, resol type phenol resins, aryl alkylene type phenol resins, and the like. As a phenol resin, one of these may be used alone, two or more having different weight average molecular weights may be used in combination, and one or two or more thereof and a prepolymer thereof may be used in combination. May be. Among these, aryl alkylene type phenol resins are particularly preferable. Thereby, the tolerance with respect to the chemical | medical solution process or plasma process of the primer layer 113 can be improved further.

  Examples of the aryl alkylene type phenol resin include a xylylene type phenol resin and a biphenyl dimethylene type phenol resin. A biphenyl dimethylene type phenol resin can be shown by the following general formula (VIII), for example.

  The repeating unit n of the biphenyl dimethylene type phenol resin represented by the general formula (VIII) is an arbitrary integer. The repeating unit n is not particularly limited, but is preferably 1 or more and more preferably 2 or more. Heat resistance can be improved more as the repeating unit n is more than the said lower limit. The repeating unit n is not particularly limited, but is preferably 12 or less, and more preferably 8 or less. When the repeating unit n is not more than the above upper limit value, compatibility with other resins is improved, and workability can be improved.

  Although content of a phenol resin is not specifically limited, 1 mass% or more is preferable with respect to the whole primer resin composition P, and 5 mass% or more is more preferable. Heat resistance can be improved further as content of a phenol resin is more than the said lower limit. Further, the content of the phenol resin is not particularly limited, but is preferably 55% by mass or less, and more preferably 40% by mass or less with respect to the entire primer resin composition P. When the content of the phenol resin is not more than the above upper limit value, the characteristics of low thermal expansion can be improved.

  Although the weight average molecular weight (Mw) of a phenol resin is not specifically limited, Mw400 or more is preferable and especially Mw500 or more is preferable. When Mw is equal to or greater than the lower limit, it is possible to suppress the occurrence of tackiness in the primer layer 113. The Mw of the phenol resin is not particularly limited, but is preferably 18,000 or less, and particularly preferably 15,000 or less. When Mw is not more than the above upper limit value, a more uniform primer layer 113 can be obtained. The Mw of the phenol resin can be measured by GPC, for example.

  In the case of using an epoxy resin or a phenol resin as the thermosetting resin (A), the primer resin composition P may further use a cyanate resin. By using cyanate resin, the linear expansion coefficient of the primer layer 113 can be reduced. Further, the cyanate resin is excellent in electrical characteristics (low dielectric constant, low dielectric loss tangent), mechanical strength, and the like.

  Examples of the cyanate resin that can be used include those obtained by reacting a cyanogen halide compound with phenols, and those obtained by prepolymerization by a method such as heating as required. Specifically, bisphenol type cyanate resins such as novolac type cyanate resin, bisphenol A type cyanate resin, bisphenol E type cyanate resin, tetramethylbisphenol F type cyanate resin; naphthol aralkyl type polyvalent naphthols, and cyanogen halides Cyanate resin obtained by reaction of; dicyclopentadiene type cyanate resin; biphenyl alkyl type cyanate resin. Among these, novolac type cyanate resin is preferable. By using the novolac type cyanate resin, the crosslink density is increased and the heat resistance is improved.

The reason for this is that the novolak cyanate resin forms a triazine ring after the curing reaction. Furthermore, it is considered that novolak-type cyanate resin has a high benzene ring ratio due to its structure and is easily carbonized. Further, the primer layer 113 containing a novolac type cyanate resin has excellent rigidity. Accordingly, the resistance of the primer layer 113 to chemical treatment or plasma treatment can be further improved.
As a novolak-type cyanate resin, what is shown by the following general formula (I) can be used, for example.

  The average repeating unit n of the novolak type cyanate resin represented by the general formula (I) is an arbitrary integer. The average repeating unit n is not particularly limited, but is preferably 1 or more, and more preferably 2 or more. When the average repeating unit n is not less than the above lower limit, the heat resistance of the novolak cyanate resin is improved, and it is possible to suppress the demerization and volatilization of the low mer during heating. The average repeating unit n is not particularly limited, but is preferably 10 or less, more preferably 7 or less. When n is less than or equal to the above upper limit value, it is possible to suppress an increase in melt viscosity and improve the moldability of the primer layer 113.

  As the cyanate resin, a naphthol type cyanate resin represented by the following general formula (II) is also preferably used. The naphthol type cyanate resin represented by the following general formula (II) includes, for example, naphthols such as α-naphthol and β-naphthol, p-xylylene glycol, α, α′-dimethoxy-p-xylene, 1,4- It is obtained by condensing naphthol aralkyl resin obtained by reaction with di (2-hydroxy-2-propyl) benzene and cyanic acid. The repeating unit n in the general formula (II) is preferably 10 or less. When the repeating unit n is 10 or less, a more uniform primer layer 113 can be obtained. In addition, intramolecular polymerization hardly occurs at the time of synthesis, the liquid separation property at the time of washing with water tends to be improved, and the decrease in yield tends to be prevented.

（式中、Ｒは水素原子またはメチル基を示し、ｎは１以上の整数を示す。）

(In the formula, R represents a hydrogen atom or a methyl group, and n represents an integer of 1 or more.)

  As the cyanate resin, a dicyclopentadiene type cyanate resin represented by the following general formula (III) is also preferably used. In the dicyclopentadiene type cyanate resin represented by the following general formula (III), the repeating unit n of the following general formula (III) is preferably 0 or more and 8 or less. When the repeating unit n is 8 or less, a more uniform primer layer 113 can be obtained. Moreover, the low hygroscopicity and chemical resistance of the primer layer 113 can be improved by using a dicyclopentadiene type cyanate resin.

（ｎは０以上８以下の整数を示す。）

(N represents an integer of 0 or more and 8 or less.)

Although the weight average molecular weight (Mw) of cyanate resin is not specifically limited, Mw500 or more is preferable and Mw600 or more is more preferable. When Mw is equal to or more than the above lower limit, it is possible to suppress the occurrence of tackiness when the primer layer 113 is produced, and when the primer layers 113 are in contact with each other, the primer layers 113 may adhere to each other or the primer layer 113 may be transferred. Can be suppressed. Mw is not particularly limited, but is preferably Mw 4,500 or less, and more preferably Mw 3,000 or less. Further, when Mw is not more than the above upper limit value, it is possible to suppress the reaction from being accelerated, and it is possible to prevent the primer layer 113 from being defective or the peel strength between the primer layer 113 and the circuit layer 105 from being lowered. be able to.
Mw of cyanate resin can be measured by GPC (gel permeation chromatography, standard substance: polystyrene conversion), for example.

  Moreover, cyanate resin may be used individually by 1 type, may use together 2 or more types which have different Mw, and may use 1 type, or 2 or more types, and those prepolymers together.

  The content of the thermosetting resin (A) contained in the primer resin composition P may be appropriately adjusted according to the purpose, and is not particularly limited, but is 5% by mass with respect to the entire primer resin composition P. It is preferably 90% by mass or less, more preferably 10% by mass or more and 80% by mass or less, and particularly preferably 20% by mass or more and 50% by mass or less. When the content of the thermosetting resin is equal to or higher than the lower limit, handling properties are improved and the primer layer 113 can be easily formed. When the content of the thermosetting resin is not more than the above upper limit value, the strength, flame retardancy and low thermal expansion of the primer layer 113 can be improved.

(Inorganic filler)
The primer resin composition P used for the primer layer 113 preferably contains an inorganic filler (B) in addition to the thermosetting resin (A). Thereby, mechanical strength and rigidity can be improved. Furthermore, the low thermal expansion of the primer layer 113 can be further improved.

  Examples of the inorganic filler (B) include silicates such as talc, fired clay, unfired clay, mica and glass; oxides such as titanium oxide, alumina, boehmite, silica and fused silica; calcium carbonate and magnesium carbonate Carbonates such as hydrotalcite; hydroxides such as aluminum hydroxide, magnesium hydroxide and calcium hydroxide; sulfates or sulfites such as barium sulfate, calcium sulfate and calcium sulfite; zinc borate, barium metaborate, Borates such as aluminum borate, calcium borate and sodium borate; nitrides such as aluminum nitride, boron nitride, silicon nitride and carbon nitride; titanates such as strontium titanate and barium titanate; Can do.

  As the inorganic filler (B), one of these may be used alone, or two or more may be used in combination. Among these, silica is particularly preferable. Silica has a crushed shape and a spherical shape. In order to ensure high filling of the inorganic filler (B), it is possible to adopt a usage method suited to the purpose, such as using spherical silica to lower the melt viscosity of the primer resin composition P.

Although the average particle diameter of an inorganic filler (B) is not specifically limited, 0.01 micrometer or more is preferable and 0.05 micrometer or more is more preferable. When the average particle diameter of the inorganic filler (B) is not less than the above lower limit, the viscosity of the varnish can be suppressed from being increased, and workability at the time of preparing the primer layer 113 can be improved. The average particle size of the inorganic filler (B) is not particularly limited, but is preferably 5.0 μm or less, more preferably 2.0 μm or less, and further preferably 1.0 μm or less. When the average particle size of the inorganic filler (B) is not more than the above upper limit, phenomena such as sedimentation of the inorganic filler (B) in the varnish can be suppressed, and a more uniform primer layer 113 can be obtained. Further, when the circuit dimension of the printed wiring board 100 is less than 20/20 μm, L / S can be suppressed from affecting the insulation between the wirings.
The average particle size of the inorganic filler (B) is measured, for example, by measuring the particle size distribution of the particles on a volume basis using a laser diffraction particle size distribution analyzer (manufactured by HORIBA, LA-500), and the median diameter (D ₅₀ ) is determined. The average particle diameter can be set.

  Further, the inorganic filler (B) is not particularly limited, but an inorganic filler (B) having a monodispersed average particle diameter may be used, or an inorganic filler (B) having a polydispersed average particle diameter may be used. May be. Further, the inorganic filler (B) having a monodispersed and / or polydispersed average particle size may be used alone or in combination of two or more.

  The inorganic filler (B) is preferably spherical silica having an average particle size of 5.0 μm or less, more preferably spherical silica having an average particle size of 0.01 μm to 2.0 μm, and particularly preferably 0.05 μm to 1.0 μm. It is. Thereby, the filling property of an inorganic filler (B) can further be improved.

  Although content of an inorganic filler (B) is not specifically limited, 1 to 60 weight% is preferable with respect to the whole primer resin composition P, and 5 to 50 weight% is more preferable. When the content is in the above range, the primer layer 113 can have particularly low thermal expansion and low water absorption.

(Other additives)
In addition, additives such as a coupling agent, a curing accelerator, a curing agent, a thermoplastic resin, and an organic filler can be appropriately added to the primer resin composition P as necessary. The primer resin composition P used in the present embodiment can be suitably used in a liquid form in which the above components are dissolved and / or dispersed with an organic solvent or the like.

  By using the coupling agent, the wettability of the interface between the thermosetting resin (A) and the inorganic filler (B) can be improved. Therefore, it is preferable to use a coupling agent, and the heat resistance of the primer layer 113 can be improved.

  As the coupling agent, any of those usually used as a coupling agent can be used. Specifically, an epoxy silane coupling agent, a cationic silane coupling agent, an aminosilane coupling agent, a titanate coupling agent, and silicone. It is preferable to use one or more coupling agents selected from oil-type coupling agents. Thereby, wettability with the interface of an inorganic filler (B) can be made high, and, thereby, heat resistance can be improved more.

  The addition amount of the coupling agent is not particularly limited because it depends on the specific surface area of the inorganic filler (B), but is preferably 0.05 parts by mass or more with respect to 100 parts by mass of the inorganic filler (B). More than mass part is more preferable. When the content of the coupling agent is not less than the above lower limit, the inorganic filler (B) can be sufficiently covered, and the heat resistance of the primer layer 113 can be improved. Moreover, the addition amount of the coupling agent is not particularly limited, but is preferably 5 parts by mass or less, and more preferably 3 parts by mass or less. When the content is not more than the above upper limit value, it is possible to suppress the influence on the reaction, and it is possible to suppress a decrease in the bending strength of the primer layer 113 and the like.

  A well-known thing can be used as a hardening accelerator. For example, organic metal salts such as zinc naphthenate, cobalt naphthenate, tin octylate, cobalt octylate, bisacetylacetonate cobalt (II), trisacetylacetonate cobalt (III); triethylamine, tributylamine, diazabicyclo [2, 2,2] tertiary amines such as octane; 2-phenyl-4-methylimidazole, 2-ethyl-4-methylimidazole, 2-ethyl-4-ethylimidazole, 2-phenyl-4-ethylimidazole, 2- Imidazoles such as phenyl-4-methyl-5-hydroxyimidazole and 2-phenyl-4,5-dihydroxyimidazole; phenolic compounds such as phenol, bisphenol A and nonylphenol; acetic acid, benzoic acid, salicylic acid, paratoluenesulfonic acid Which organic acid; onium salt compounds; and the like. As the curing accelerator, one kind including these derivatives may be used alone, or two or more kinds including these derivatives may be used in combination.

  The onium salt compound is not particularly limited, and for example, an onium salt compound represented by the following general formula (IX) can be used.

(In the formula, P represents a phosphorus atom, R ¹ , R ² , R ³ and R ⁴ each represents an organic group having a substituted or unsubstituted aromatic ring or heterocyclic ring, or a substituted or unsubstituted aliphatic group. A ⁻ may be the same as or different from each other, and A ⁻ is an anion of an n (n ≧ 1) -valent proton donor having at least one proton that can be released to the outside of the molecule, or a complex anion thereof. Is shown.)

  Although content of a hardening accelerator is not specifically limited, 0.01 weight% or more and 5 weight% or less are preferable with respect to the whole primer resin composition P, and 0.1 weight% or more and 2 weight% or less are more preferable. When the content of the curing accelerator is not less than the above lower limit, the effect of promoting curing can be sufficiently exerted. When the content of the curing accelerator is not more than the above upper limit value, the preservability of the primer layer 113 can be further improved.

  The primer resin composition P in this embodiment is a thermoplastic resin such as phenoxy resin, polyimide resin, polyamide resin, polyamideimide resin, polyphenylene oxide resin, polyethersulfone resin, polyester resin, polyethylene resin, polystyrene resin; styrene-butadiene Polystyrene thermoplastic elastomers such as copolymers and styrene-isoprene copolymers; polyolefin thermoplastic elastomers; thermoplastic elastomers such as polyamide elastomers and polyester elastomers; polybutadiene, epoxy-modified polybutadiene, acrylic-modified polybutadiene, methacryl-modified polybutadiene A diene elastomer such as Among these, phenoxy resin, polyamide resin, polyphenylene oxide resin, and epoxy-modified polybutadiene are preferable.

  Examples of the phenoxy resin include a phenoxy resin having a bisphenol skeleton, a phenoxy resin having a naphthalene skeleton, a phenoxy resin having an anthracene skeleton, and a phenoxy resin having a biphenyl skeleton. A phenoxy resin having a structure having a plurality of these skeletons can also be used.

Among these, it is preferable to use a phenoxy resin having a biphenyl skeleton and a bisphenol S skeleton as the phenoxy resin. The rigidity of the biphenyl skeleton can increase the glass transition temperature of the phenoxy resin, and the presence of the bisphenol S skeleton can improve the adhesion between the phenoxy resin and the metal. As a result, the heat resistance of the primer layer 113 can be improved, and the adhesion between the core layer 111 and the circuit layer 105 can be further improved. It is also preferable to use a phenoxy resin having a bisphenol A skeleton and a bisphenol F skeleton as the phenoxy resin. Thereby, the adhesiveness between the core layer 111 and the circuit layer 105 can be further improved.
It is also preferable to use a phenoxy resin having a bisphenolacetophenone structure represented by the following general formula (X).

(In the formula, R ₁ may be the same as or different from each other, and is a group selected from a hydrogen atom, a hydrocarbon group having 1 to 10 carbon atoms, and a halogen element, and R ₂ is a hydrogen atom, carbon, A group selected from a hydrocarbon group having a number of 1 to 10 and a halogen element, R ₃ is a hydrogen atom or a hydrocarbon group having a carbon number of 1 to 10 and m is an integer of 0 to 5. )

  Since the phenoxy resin containing a bisphenol acetophenone structure has a bulky structure, it is excellent in solvent solubility and compatibility with the thermosetting resin (A) to be blended. Moreover, since a uniform rough surface can be formed with low roughness, the fine wiring formability is excellent.

  The phenoxy resin having a bisphenol acetophenone structure can be synthesized by a known method such as a method in which an epoxy resin and a phenol resin are polymerized with a catalyst.

  The phenoxy resin having a bisphenol acetophenone structure may contain a structure other than the bisphenol acetophenone structure of the general formula (X), and the structure is not particularly limited. Examples of the structure include a type, a phenol novolak type, and a cresol novolak type. Among them, those containing a biphenyl structure are preferable because of their high glass transition temperature.

  The content of the bisphenol acetophenone structure of the general formula (X) in the phenoxy resin containing a bisphenol acetophenone structure is not particularly limited, but is preferably 5 mol% to 95 mol%, more preferably 10 mol% to 85 mol%. Or less, more preferably 15 mol% or more and 75 mol% or less. The effect which improves heat resistance and moisture-proof reliability can fully be exhibited as content is more than the said lower limit. Moreover, solvent solubility can be improved as content is below the said upper limit.

  The weight average molecular weight (Mw) of the phenoxy resin is not particularly limited, but is preferably from 5,000 to 100,000, more preferably from 10,000 to 70,000, and further preferably from 15,000 to 50,000. . When Mw is not more than the above upper limit, compatibility with other resins and solubility in a solvent can be improved. The film forming property of the primer layer 113 can be improved as it is more than the said lower limit.

  The content of the phenoxy resin is not particularly limited, but is preferably 0.5% by mass or more and 40% by mass or less, and preferably 1% by mass or more and 25% by mass or less with respect to the primer resin composition P excluding the inorganic filler (B). More preferred. When the content is not less than the above lower limit, the mechanical strength of the primer layer 113 and the adhesion between the core layer 111 and the circuit layer 105 can be improved. If it is not more than the above upper limit value, an increase in the coefficient of thermal expansion of the primer layer 113 can be suppressed, and the heat resistance can be improved.

  The primer resin composition P may contain additives other than the above components such as pigments, dyes, antifoaming agents, leveling agents, ultraviolet absorbers, foaming agents, antioxidants, flame retardants, and ion scavengers as necessary. It may be added.

  Examples of pigments include kaolin, synthetic iron oxide red, cadmium yellow, nickel titanium yellow, strontium yellow, hydrous chromium oxide, chromium oxide, cobalt aluminate, synthetic ultramarine blue and other inorganic pigments, phthalocyanine polycyclic pigments, azo pigments, etc. Etc.

  Examples of the dye include isoindolinone, isoindoline, quinophthalone, xanthene, diketopyrrolopyrrole, perylene, perinone, anthraquinone, indigoid, oxazine, quinacridone, benzimidazolone, violanthrone, phthalocyanine, and azomethine.

<Core layer>
The core layer 111 is not particularly limited as long as it is made of an insulating material. For example, an epoxy resin, a glass substrate-epoxy resin laminate, a glass substrate-polyimide resin laminate, a glass substrate-Teflon (registered) (Trademark) Resin laminate, glass substrate-bismaleimide / triazine resin laminate, glass substrate-cyanate resin laminate, glass substrate-polyphenylene ether resin laminate, polyester resin, ceramic, resin impregnated ceramic, prepreg Or the like. Among these, the prepreg is a sheet-like material, and is excellent in various properties such as dielectric properties, mechanical and electrical connection reliability under high temperature and high humidity, and suitable for the production of the core layer 111 for a printed wiring board. .

<Build-up layer>
The buildup layer 115 is not particularly limited as long as it is made of an insulating material. For example, the buildup layer 115 can be made of either a resin film or a prepreg. Among these, the prepreg is a sheet-like material, and has excellent dielectric properties, various characteristics such as mechanical and electrical connection reliability under high temperature and high humidity, and is suitable for manufacturing the build-up layer 115 for printed wiring boards. preferable.

[Printed wiring board manufacturing method]
It continues and demonstrates an example of the manufacturing method of the printed wiring board 100 which concerns on this embodiment. FIG. 5 is a cross-sectional view schematically showing an example of a method for manufacturing the printed wiring board 100 according to the embodiment of the present invention.

  Moreover, in order to obtain the printed wiring board 100 of this embodiment, it is important to appropriately select each material used for the primer resin composition P described above and appropriately adjust the blending amount of each material. It is also important to appropriately adjust the conditions for the chemical treatment or plasma treatment performed on at least one surface 110 of the insulating layer 103.

  Hereinafter, an example of a method for manufacturing the printed wiring board 100 according to the present embodiment will be described. However, the manufacturing method of the printed wiring board 100 according to the present embodiment is not limited to the following example.

(Production of metal-clad laminate)
First, the metal-clad laminate 200 is produced by laminating the metal layer 203 on both sides or one side of the core layer 111 via the primer layer 113 (FIG. 5A). This will be specifically described below. First, a solvent is added to the primer resin composition P described above to form a resin varnish, and the resin varnish is applied onto the metal layer 203 and dried to obtain the metal layer 203 with the primer layer 113.
Next, the obtained metal layer 203 with the primer layer 113 is disposed with the primer layer 113 inside, and is press-laminated on the core layer 111, whereby the metal-clad laminate 200 can be obtained (FIG. 5A). ).
The primer layer 113 may be laminated only on one side of the core layer 111 or on both sides. The metal-clad laminate 200 according to this embodiment can also be manufactured by a method in which the primer layer 113 is laminated on the surface of the core layer 111 and the metal layer 203 is laminated on the surface of the primer layer 113.
6, when the printed wiring board 130 in which the insulating layer 103 includes the core layer 111, the buildup layer 115, and the primer layer 113 is manufactured, the primer layer 113 is interposed on the surface of the buildup layer 115. Thus, the metal-clad laminate 200 can be produced by laminating the metal layer 203.

  The solvent for dissolving the primer resin composition P desirably has good solubility in the thermosetting resin (A), but a poor solvent may be used as long as it does not adversely affect the primer resin composition P. Examples of the solvent exhibiting good solubility include acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, cyclohexanone, dimethylformamide, dimethylacetamide, N-methylpyrrolidone and the like.

  For the metal layer 203, a metal foil can be suitably used. The surface of this metal foil is usually subjected to chromate treatment. Examples of the metal constituting the metal layer 203 include copper and copper alloys, aluminum and aluminum alloys, silver and silver alloys, gold and gold alloys, zinc and zinc alloys, nickel and nickel alloys, tin and Examples thereof include tin alloys, iron and iron alloys, Kovar (trade name), 42 alloys, Fe-Ni alloys such as Invar and Super Invar, W or Mo, and the like. Among these, the metal constituting the metal layer 203 is preferably copper or a copper alloy because of its excellent conductivity, easy circuit formation by etching, and low cost. As the metal layer 203, a metal foil with a carrier or the like can also be used.

  The thickness of the metal layer 203 is preferably 0.5 μm or more and 20 μm or less, and more preferably 1.5 μm or more and 12 μm or less. The metal layer 203 is particularly preferably an electrolytic copper foil or a rolled copper foil having a surface roughness (Rz) of 0.5 μm or more and 3.0 μm or less and subjected to a chromate treatment.

Next, a via hole 101 is formed in the metal-clad laminate 200 (FIG. 5B). The via hole 101 can be formed using, for example, a drilling machine or laser irradiation. Examples of the laser used for laser irradiation include an excimer laser, a UV laser, and a carbon dioxide gas laser.
Resin residues and the like after forming the via hole 101 may be removed by an oxidizing agent such as permanganate or dichromate.

  Next, the metal layer 203 is removed by etching (FIG. 5C). Note that the via hole 101 may be formed after the metal layer 203 is removed from the metal-clad laminate 200 by etching.

  Next, chemical treatment or plasma treatment is performed on at least one surface 110 of the insulating layer 103 (FIG. 5D). By chemical treatment or plasma treatment, the average value of the ratio of chromium amount to carbon amount measured by X-ray photoelectron spectroscopy in the peripheral region C1 of the via hole 101 on one surface 110 of the insulating layer 103 is reduced to 0.090 or less. And 10-point average roughness Rz of the one surface 110 of the insulating layer 103 measured based on JIS B0601: 2001 shall be 1.2 micrometers or more.

  The chemical treatment is not particularly limited, and examples thereof include a method using an oxidant solution having an organic substance decomposing action. Examples of the plasma treatment include a method of directly irradiating a target object with active species (plasma, radical, etc.) having a strong oxidizing action to remove organic residue.

Specific examples of the chemical treatment include a method of performing a swelling treatment on the surface of the insulating layer 103, performing an etching by an alkali treatment, and subsequently performing a neutralization treatment.
Examples of the plasma treatment include a method of performing discharge by a high frequency power source of about several kHz to several tens of MHz in a gas atmosphere of several mTorr to several Torr. In addition, as a use gas, reactive gas, such as oxygen, or inert gas, such as nitrogen and argon, can be used, for example. Depending on the pressure and the type of gas used, the gas components activated by the plasma may cause chemical reactions, physical reactions due to collision (bombing) of the gas molecules themselves, or both. Surface fouling due to molecules can be removed. Cleaning by plasma treatment can be performed by, for example, a parallel plate method.
By the plasma treatment, it is possible to remove a strong resin composition residue that cannot be removed by cleaning with a chemical solution.

  Next, the circuit layer 105 according to the present embodiment is formed. The circuit layer 105 according to the present embodiment can be formed by a semi-additive process. This will be specifically described below.

  First, an electroless metal plating film 108 is formed on at least one surface 110 of the insulating layer 103 by using an electroless plating method (FIG. 5E). An example of the electroless plating method will be described. For example, first, a catalyst nucleus is provided on at least one surface 110 of the insulating layer 103. The catalyst nucleus is not particularly limited. For example, a noble metal ion or palladium colloid can be used. Subsequently, an electroless metal plating film 108 is formed by electroless plating using the catalyst nucleus as a nucleus. For electroless plating, for example, one containing copper sulfate, formalin, complexing agent, sodium hydroxide, or the like can be used. In addition, it is preferable to heat-process 100-250 degreeC after electroless plating, and to stabilize a plating film. A heat treatment at 120 to 180 ° C. is particularly preferable in that a film capable of suppressing oxidation can be formed. The average thickness of the electroless metal plating film 108 is, for example, about 0.1 to 1 μm.

  Next, a plating resist 201 having a predetermined opening pattern is formed on the electroless metal plating film 108. This opening pattern corresponds to, for example, a circuit pattern. The plating resist 201 is not particularly limited, and known materials can be used, but liquid and dry films can be used. In the case of forming fine wiring, it is preferable to use a photosensitive dry film or the like as the plating resist 201. An example using a photosensitive dry film will be described. For example, a photosensitive dry film is laminated on the electroless metal plating film 108, the non-circuit formation region is exposed and photocured, and the unexposed portion is dissolved and removed with a developer. The plating resist 201 is formed by leaving the cured photosensitive dry film.

  Next, as shown in FIG. 5 (f), an electrolytic metal plating layer 109 is formed by electroplating at least inside the opening pattern of the plating resist 201 and on the electroless metal plating film 108. Although it does not specifically limit as electroplating, The well-known method used with a normal printed wiring board can be used, For example, an electric current is sent through a plating solution in the state immersed in plating solutions, such as copper sulfate. Etc. can be used. The electrolytic metal plating layer 109 may be a single layer or may have a multilayer structure. The material of the electrolytic metal plating layer 109 is not particularly limited, and for example, one or more of copper, copper alloy, 42 alloy, nickel, iron, chromium, tungsten, gold, and solder can be used.

  Next, as shown in FIG. 5G, the plating resist 201 is removed using an alkaline stripping solution, sulfuric acid, a commercially available resist stripping solution, or the like.

  Next, as shown in FIG. 5G, the electroless metal plating film 108 other than the region where the electrolytic metal plating layer 109 is formed is removed. For example, the electroless metal plating film 108 can be removed by using soft etching (flash etching) or the like. Here, the soft etching treatment can be performed, for example, by etching using an etchant containing sulfuric acid and hydrogen peroxide. Thereby, the circuit layer 105 can be formed. The circuit layer 105 is composed of the electroless metal plating film 108 and the electrolytic metal plating layer 109.

  The printed wiring board 100 of this embodiment is obtained by the above.

(Semiconductor package)
Next, the semiconductor package 300 according to the present embodiment will be described. FIG. 3 is a cross-sectional view showing an example of the configuration of the semiconductor package 300 according to the embodiment of the present invention. FIG. 7 is a cross-sectional view showing an example of the configuration of the semiconductor package 300 according to the embodiment of the present invention. The printed wiring board 100 according to the present embodiment can be used for a semiconductor package 300 as shown in FIGS. A method for manufacturing the semiconductor package 300 is not particularly limited, and examples thereof include the following methods.

  First, the build-up layer 115 (FIG. 7) is laminated on the printed wiring board 100 according to the present embodiment as necessary, and the steps of interlayer connection and circuit formation by a semi-additive process are repeated. And the soldering resist layer 301 is laminated | stacked as needed.

  The method for forming the solder resist layer 301 is not particularly limited. For example, a method of laminating a dry film type solder resist and forming it by exposure and development, or a method of printing a liquid resist by exposure and development. By the method.

  Subsequently, by performing a reflow process, the semiconductor element 307 is fixed to the connection terminal which is a part of the wiring pattern via the solder bump 310. Thereafter, the semiconductor element 307, the solder bump 310, and the like are sealed with a sealing material 313, whereby the semiconductor package 300 as shown in FIG. 3 is obtained.

(Semiconductor device)
Next, the semiconductor device 400 according to the present embodiment will be described. FIG. 4 is a cross-sectional view showing an example of the configuration of the semiconductor device according to the embodiment of the present invention. FIG. 8 is a cross-sectional view showing an example of the configuration of the semiconductor device according to the embodiment of the present invention.
The printed wiring board 100 and the semiconductor package 300 can be used in a semiconductor device 400 as shown in FIGS. A method for manufacturing the semiconductor device 400 is not particularly limited, and examples thereof include the following methods.

  First, a solder bump 410 is formed by applying a solder paste to the opening of the solder resist layer 401 of the obtained semiconductor package 300 and then mounting a solder ball, followed by a reflow process. The solder bump 410 can also be formed by attaching a previously prepared solder ball to the opening.

  Next, the semiconductor package 300 is mounted on the mounting substrate 420 by bonding the connection terminals 425 of the mounting substrate 420 and the solder bumps 410, and the semiconductor device 400 shown in FIGS. 4 and 8 is obtained.

  As described above, according to the present embodiment, it is possible to obtain the printed wiring board 100, the semiconductor package 300, and the semiconductor device 400 that are excellent in insulation reliability between wirings.

  As mentioned above, although embodiment of this invention was described, these are illustrations of this invention and various structures other than the above are also employable.

  Hereinafter, although an example and a comparative example explain the present invention, the present invention is not limited to these. In addition, in an Example, unless otherwise specified, a part represents a mass part. Moreover, each thickness is represented by the average film thickness.

  In the examples and comparative examples, the following raw materials were used.

(1) Epoxy resin A (NC-3000, biphenyl aralkyl type epoxy manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent 175)
(2) Epoxy resin B (jER604, tetraglycidyldiaminodiphenylmethane manufactured by Mitsubishi Chemical Corporation, epoxy equivalent 120)
(3) Phenol resin A (GPH-65, Nippon Kayaku Co., Ltd. biphenyl aralkyl type phenol, hydroxyl group equivalent 198)
(4) Phenol resin B (SN-485, manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., naphthol aralkyl type phenol, hydroxyl group equivalent 210)
(5) Phenol resin C (LA-7054, triazine skeleton-containing phenol novolak manufactured by DIC, hydroxyl equivalent 125)
(6) Cyanate resin (PT-30, Lonza phenol novolac-type cyanate ester)
(7) Phenoxy resin (YX6954BH30, manufactured by Mitsubishi Chemical Corporation, biphenyl type phenoxy, MW = 38,000)
(8) Polyamide (BPAM-155, a phenol-modified polyamide manufactured by Nippon Kayaku Co., Ltd.)
(9) Curing accelerator (2E4MZ, 2-ethyl-4-methylimidazole manufactured by Shikoku Chemicals)
(10) Inorganic filler A (SFP-20M, spherical silica manufactured by Denki Kagaku Kogyo Co., Ltd., average particle size 0.35 μm)
(11) Inorganic filler B (Achilox200SM, Boehmite manufactured by Navaltech, average particle size 0.3 μm)
(12) Copper foil A with roughening (MT18Ex-2, ultrathin copper foil with carrier manufactured by Mitsui Mining & Smelting Co., Ltd., carrier 18 μm, ultrathin foil 2 μm, Rz = 1.9 μm)
(13) Copper foil B with roughening (NSAP-2B, Nippon Electrolytic Co., Ltd. ultrathin copper foil with carrier, carrier 18 μm, ultrathin foil 2 μm, Rz = 1.4 μm)
(14) Unroughened copper foil C (NS-VLP-9, unroughened foil by Mitsui Mining & Smelting Co., Ltd., 9 μm, Rz = 1.0 μm)

Example 1
1. Preparation of resin varnish 46.0 parts by mass of epoxy resin A, 32.0 parts by mass of phenol resin A, 20.0 parts by mass of phenoxy resin, and 2.0 parts by mass of a curing accelerator were dissolved and dispersed in the solvent methyl ethyl ketone. Next, it stirred for 30 minutes using the high-speed stirring apparatus, it adjusted so that it might become 70 mass% of non volatile matters, and the varnish (resin varnish) of the resin material was prepared.

2. Preparation of Copper Foil with Primer Layer A resin varnish was coated on a roughened copper foil A using a gravure coater so that the thickness of the resin layer after drying was 4 μm, and this was applied at 160 ° C. Then, the solvent was removed by drying for 5 minutes using a drying apparatus to obtain a copper foil with a primer layer.

3. Fabrication of copper-clad laminate Overlaying two 0.1 mm prepregs (EI-6785GS-FG manufactured by Sumitomo Bakelite Co., Ltd.) on both sides with a copper foil with a primer layer (with the primer layer side facing the prepreg side) It was. Subsequently, the copper clad laminated board was obtained by heat-press-molding at 220 degreeC and 3.0 Mpa for 2 hours. The thickness of the core layer (part consisting of a resin substrate) of the obtained laminate was 0.20 mm.

4). Production of Printed Wiring Board Using the copper-clad laminate obtained above, the copper foil was removed by etching to expose the primer layer. Next, a through hole (through hole) was formed by a carbon dioxide laser. Next, an inner layer circuit board in which a fine circuit pattern was formed on both surfaces by a semi-additive method (residual copper ratio 70%, L / S = 15/15 μm) was prepared.
Similarly, a 0.03 mm prepreg (EI-6785GS-FG manufactured by Sumitomo Bakelite Co., Ltd.) and a copper foil with a primer layer are placed on both sides (so that the primer layer side becomes the prepreg side), and 220 ° C., 3.0 MPa. A copper-clad laminate was obtained by heating and pressing for 2 hours. Similarly to the above, the copper foil was removed by etching to expose the primer layer. Next, blind via holes (non-through holes) were formed by a carbon dioxide gas laser. Next, a printed wiring board having a fine circuit pattern formed on both surfaces by a semi-additive method (residual copper ratio: 50%, L / S = 15/15 μm) was obtained.

(Examples 2-7, Comparative Examples 1-5)
1. Production of Copper Clad Laminate A copper clad laminate was produced in the same manner as in Example 1 except that the types of materials used and their blending ratios were changed to those shown in Table 1, respectively.

2. Production of Printed Wiring Board Using the copper-clad laminate obtained above, the copper foil was removed by etching to expose the primer layer. Next, a through hole (through hole) was formed by a carbon dioxide laser. Next, various treatments (chemical solution treatments A to C or dry treatment) to be described later were performed to adjust the Cr amount on the surface. Next, an inner layer circuit board in which fine circuit patterns were formed on both sides by a semi-additive method (residual copper ratio: 70%, L / S = 15/15 μm) was prepared.
Similarly, a 0.03 mm prepreg (EI-6785GS-FG manufactured by Sumitomo Bakelite Co., Ltd.) and a copper foil with a primer layer are placed on both sides (so that the primer layer side becomes the prepreg side), and 220 ° C., 3.0 MPa. Then, copper-clad laminates were obtained by heating and pressing for 2 hours. Similarly to the above, the copper foil was removed by etching to expose the primer layer. Next, blind via holes (non-through holes) were formed by a carbon dioxide gas laser. Next, various treatments (chemical treatments A to C or dry treatment) were performed, respectively, and the Cr amount on the surface was adjusted. Next, printed circuit boards in which fine circuit patterns were formed on both surfaces by a semi-additive method (residual copper ratio: 50%, L / S = 15/15 μm) were obtained.

(Chemical treatment)
Chemical treatment A: An acidic neutralization solution (NE: Reduction Solution Securigant P) was used for treatment at 40 ° C. for 5 minutes.
Chemical treatment B: Alkaline swelling solution (SW: Atotech Japan, Swelling Dip Securigans P) is treated at 60 ° C. for 2 minutes, and then a permanganate solution (ME: Atotech Japan, outlet) It was treated at 80 ° C. for 1 minute using a rate compact CP), and then treated at 40 ° C. for 3 minutes using an acidic neutralization solution (NE: Reduction Solution Securigant P).
Chemical treatment C: Alkaline swelling solution (SW: manufactured by Atotech Japan, Swelling Dip Securigans P) is treated at 60 ° C. for 2 minutes, and then a permanganate solution (ME: manufactured by Atotech Japan, outlet) Then, it was treated at 80 ° C. for 3 minutes using a rate compact CP), and then treated at 40 ° C. for 3 minutes using an acidic neutralization solution (NE: Reduction Solution Securigant P).

(Dry processing)
A vacuum was drawn in a box equipped with a vacuum chamber until the degree of vacuum became 1 × 10 ⁻³ Pa, and then N ₂ gas was introduced into the vacuum chamber to adjust the degree of vacuum to 0.2 Pa. At this time, the flow rate of N ₂ gas was 20 sccm. Next, a DC voltage was applied between a pair of parallel plate type electrodes to generate low-temperature plasma in the vacuum chamber, and the exposed surface of the substrate held in the substrate holding part was subjected to plasma treatment. The plasma treatment was performed at 300 W (power density 0.27 W / cm ² ) for 2 minutes.

  The following evaluation was performed about the copper clad laminated board and printed wiring board which were obtained by the Example and the comparative example, respectively.

(1) Residual Cr amount (to C amount ratio)
The resin surface of a printed wiring board after chemical treatment or plasma treatment (before forming a fine circuit pattern by a semi-additive method) is measured by an electron probe microanalyzer (EPMA) and the amount of remaining Cr is analyzed. And the value of chromium mol% / carbon mol% was calculated.

(2) Surface roughness (Rz)
The resin surface of the printed wiring board after chemical treatment or plasma treatment (before formation of a fine circuit pattern by a semi-additive method) was measured according to JIS B0601: 2001 using a WYKO NT1100 manufactured by Veeco, and a ten-point average roughness (Rz ) Was measured.

(3) Electroless plating property In the process of forming a fine circuit pattern by a semi-additive method, the resin surface after the entire electroless plating process was visually observed. Evaluation was made according to the following criteria.
◎: Electroless copper was uniformly deposited on the entire surface (no problem)
○: Some parts were thin, but electroless copper was attached to the entire surface (no problem in practical use)
×: Electroless copper was uneven and part of the resin surface was exposed (problem)

(4) Peel strength Instead of forming a fine circuit pattern by a semi-additive method of a printed wiring board, copper was plated on the entire surface to obtain a substrate having a 20 μm copper layer. The peel strength was measured according to JIS C-6482: 1996. Evaluation was made according to the following criteria.
○: 0.5 kN / m or more ×: Less than 0.5 kN / m

(5) Fine wiring processability About the printed wiring board after forming the fine circuit pattern of L / S = 15/15 micrometer by the semi-additive method, it evaluated by the external inspection of the thin wire | line and the copper penetration check with the laser microscope. Evaluation was made according to the following criteria.
◎: No problem in both shape and continuity ○: No short circuit or wire breakage, no problem ×: Short circuit, wire breakage

(6) Interline insulation reliability The fine circuit pattern part of L / S = 15/15 μm of the printed wiring board is covered with an insulating resin sheet (BLA-3700GS, manufactured by Sumitomo Bakelite Co., Ltd.) (after curing, cured at a temperature of 200 ° C.). A test sample was prepared. For this test sample, the insulation resistance in continuous humidity was evaluated under the conditions of a temperature of 130 ° C., a humidity of 85%, and an applied voltage of 3.3 V. A resistance value of 10 ⁶ Ω or less was regarded as a failure. Evaluation was made according to the following criteria.
◎: No failure for 300 hours or more ○: Failure in 150 to less than 300 hours ×: Failure in less than 150 hours

DESCRIPTION OF SYMBOLS 100 Printed wiring board 101 Via hole 103 Insulating layer 105 Circuit layer 107 Perimeter 108 Electroless metal plating film 109 Electrolytic metal plating layer 110 One side 111 Core layer 113 Primer layer 115 Buildup layer 118 Electroless metal plating film 119 Electrolytic metal plating layer 120 circuit layer 130 printed wiring board 200 metal-clad laminate 201 plating resist 203 metal layer 300 semiconductor package 301 solder resist layer 307 semiconductor element 310 solder bump 313 sealing material 400 semiconductor device 401 solder resist layer 410 solder bump 420 mounting board 425 connection Terminal

Claims (18)

A printed wiring board having an insulating layer having a via hole and a circuit layer provided on at least one surface of the insulating layer,
The average value of the ratio of the chromium amount to the carbon amount measured by X-ray photoelectron spectroscopy in the peripheral region of the via hole on the one surface is 0.090 or less,
A printed wiring board having a 10-point average roughness Rz of 1.2 μm or more measured on the basis of JIS B0601: 2001. The printed wiring board according to claim 1,
The printed circuit board, wherein the circuit layer includes an electroless metal plating film. In the printed wiring board according to claim 1 or 2,
The printed wiring board is obtained by circuit processing a metal-clad laminate in which a metal layer is laminated on at least one surface of the insulating layer,
The printed wiring board, wherein the metal layer laminated on the metal-clad laminate has a chromate treatment on the surface. In the printed wiring board as described in any one of Claims 1 thru | or 3,
The printed wiring board whose peel strength between the said insulating layer and the said circuit layer is 0.5 kN / m or more measured based on JIS C-6481: 1996. In the printed wiring board as described in any one of Claims 1 thru | or 4,
The printed wiring board whose thickness of the said circuit layer is 5 micrometers or more and 25 micrometers or less. In the printed wiring board as described in any one of Claims 1 thru | or 5,
The insulating layer includes a core layer and a primer layer,
The printed wiring board, wherein the primer layer is interposed between the core layer and the circuit layer. In the printed wiring board as described in any one of Claims 1 thru | or 5,
The insulating layer includes a core layer, a build-up layer, and a primer layer,
The printed wiring board, wherein the primer layer is interposed between at least one of the core layer and the circuit layer and between the buildup layer and the circuit layer. The printed wiring board according to claim 7,
The printed wiring board whose thickness of the said primer layer is 1 micrometer or more and 10 micrometers or less. In the printed wiring board according to claim 7 or 8,
The printed wiring board whose glass transition temperature by the dynamic viscoelasticity measurement of the said primer layer is 170 to 300 degreeC. In the printed wiring board as described in any one of Claims 7 thru | or 9,
The printed wiring board whose storage elastic modulus E 'in 250 degreeC of the said primer layer is 10 Mpa or more and 350 Mpa or less. In the printed wiring board as described in any one of Claims 7 thru | or 10,
The printed wiring board, wherein the primer layer includes an epoxy resin.   The semiconductor package which mounts a semiconductor element on the printed wiring board as described in any one of Claims 1 thru | or 11.   A semiconductor device comprising the semiconductor package according to claim 12 mounted on a mounting substrate. A manufacturing method for manufacturing the printed wiring board according to claim 1,
Forming a via hole in a metal-clad laminate in which a metal layer is laminated on at least one surface of the insulating layer;
Removing the metal layer by an etching process;
By chemical treatment or plasma treatment, the average value of the ratio of the chromium amount to the carbon amount measured by X-ray photoelectron spectroscopy in the peripheral region of the via hole on the one surface is reduced to 0.090 or less, and JIS B0601 : A step of measuring 10-point average roughness Rz of the one surface measured in accordance with 2001 to 1.2 μm or more;
A method for manufacturing a printed wiring board, comprising: In the manufacturing method of the printed wiring board according to claim 14,
A method for manufacturing a printed wiring board, further comprising a step of forming a circuit layer by a semi-additive process. In the manufacturing method of the printed wiring board of Claim 14 or 15,
A method for producing a printed wiring board, wherein the metal layer is formed of a chromate-treated metal foil. In the manufacturing method of the printed wiring board according to any one of claims 14 to 16,
The insulating layer includes a core layer and a primer layer,
A method for producing a printed wiring board, further comprising the step of producing the metal-clad laminate by laminating the metal layer on both sides or one side of the core layer via the primer layer. In the manufacturing method of the printed wiring board as described in any one of Claims 14 thru | or 17,
The insulating layer includes a core layer, a build-up layer, and a primer layer,
A method for producing a printed wiring board, further comprising the step of producing the metal-clad laminate by laminating the metal layer on the surface of the build-up layer via the primer layer.

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