WO2012101985A1

WO2012101985A1 - Printed wiring board and method for manufacturing printed wiring board

Info

Publication number: WO2012101985A1
Application number: PCT/JP2012/000263
Authority: WO
Inventors: 哲平伊藤; 大東　範行
Original assignee: 住友ベークライト株式会社
Priority date: 2011-01-26
Filing date: 2012-01-18
Publication date: 2012-08-02
Also published as: TWI600349B; KR20140009323A; JP2012169598A; TW201251533A; JP5929220B2

Abstract

Provided is a printed wiring board having excellent yield. This method for manufacturing a printed wiring board includes: a step wherein a carrier base material is separated from a laminated board having a carrier base material-attached copper foil (copper foil layer (104)) laminated at least on one surface (30) of an insulating layer (102); a step wherein a metal layer (115) that is thicker than the copper foil layer (104) is formed on the whole surface of the copper foil layer (104) or selectively formed on the copper foil layer; and a step wherein a pattern of a conductive circuit (119) configured of the copper foil layer (104) and the metal layer (115) is obtained by etching at least the copper foil layer (104). In a step of obtaining the conductive circuit (119), an Rp of the surface (30) of the insulating layer (102) is 4.5 μm or less and an Rku is 2.1 or more when measurement is performed conforming to JIS B0601.

Description

Printed wiring board and printed wiring board manufacturing method

The present invention relates to a printed wiring board and a method for manufacturing the printed wiring board.

With the demand for higher functionality of electronic equipment, etc., high-density integration of electronic parts, and further high-density mounting, etc. are progressing. In addition, miniaturization, thinning, high density, and multilayering are progressing.

A method for forming a conductor circuit pattern on the substrate of such a printed wiring board is described in Patent Document 1, for example.
In the method described in Patent Document 1, first, an insulating resin layer is formed on a double-sided copper-clad laminate, and after the surface of the insulating resin layer is roughened, a conductor layer is formed on the surface, It is described that a pattern of a conductor layer (conductor circuit pattern) is formed by performing etching using an etching resist as a mask. In this Patent Document 1, by reducing the roughness of the surface of the insulating resin layer, which is the underlying layer of this conductor circuit pattern, residual etching resist residue is prevented, and deterioration in wiring accuracy of the conductive circuit pattern is suppressed. It describes what you can do.
Moreover, the roughness of the surface of the insulating resin layer described in Patent Document 1 is Ra indicating the average roughness with respect to the central roughness on the peak side of the chart showing the irregularities on the surface, and the roughness on the peak side in the figure is large. It is defined by Rz indicating the average roughness of a total of 10 points of 5 points and 5 points although the roughness on the valley side is large (hereinafter, in the chart showing surface irregularities, the portion corresponding to the concave portion is the valley, The part corresponding to the convex part is sometimes called a mountain).

Japanese Patent Laid-Open No. 2005-5458

However, in the conventional process of forming a fine conductive circuit pattern, there is a limit in suppressing variation in etching characteristics of the conductor layer on the insulating resin layer. For example, in order to improve the etching characteristics of the conductor layer, it is required to reduce the surface roughness of the conductor layer.
However, as a result of investigations by the present inventors, Ra and Rz indicating surface roughness usually used in the technical field of printed wiring boards do not accurately define the shape of the surface. Even when Rz is adopted as an index and Ra and Rz on the surface of the insulating resin layer are controlled to be small, it has been found that the surface roughness of the conductor layer formed thereon varies among products. For example, Ra and Rz are indices that do not indicate the width of the peaks, and therefore, by controlling these indices, the spacing between the peaks on the surface of the underlying insulating resin layer may be widened. Indentations can occur.
Therefore, in the prior art, the etching characteristics of the conductor layer may vary, and there is room for improvement.

According to the present invention,
Separating the carrier substrate from a laminate in which a copper foil with a carrier substrate is laminated on at least one surface of the insulating layer;
Forming a metal layer thicker than the copper foil on the entire surface or selectively on the copper foil;
Obtaining a conductive circuit pattern composed of the copper foil and the metal layer by etching at least the copper foil, and
In the step of obtaining the conductive circuit pattern, when measured according to JIS B0601, the Rp on the one surface of the insulating layer is 4.5 μm or less and the Rku is 2.1 or more. A method is provided.

As a result of the study, the inventor has formed a surface shape pattern on one surface of the insulating layer when a surface shape pattern having a small peak height, a narrow peak interval, and an acute angle peak exists on one surface of the underlying insulating layer. It was thought that the variation in the etching characteristics of the copper foil was reduced.
The present inventor has controlled the appropriate value of both the index indicating that the height of the peak is small and the index indicating that the interval between the peaks is narrow and acute, the copper foil formed on the base Since variation in etching characteristics has been reduced, Rp indicating the maximum height of the mountain and Rku indicating the sharpness of the mountain (the interval between the peaks is narrow) are adopted as such indices, and Rp is 4.5 μm or less. By controlling Rku to 2.1 or more, it becomes possible to appropriately control the surface shape pattern on one surface of the insulating layer, and it can be found that variation in etching characteristics of the copper foil can be suppressed. It has come.

Moreover, according to the present invention,
An insulating layer;
Provided on one surface of the insulating layer, comprising a conductive circuit pattern composed of a copper foil and a metal layer,
Provided is a printed wiring board in which Rp on the one surface of the insulating layer is 4.5 μm or less and Rku is 2.1 or more as measured by JIS B0601.

Since Rp on one surface of the insulating layer is 4.5 μm or less and Rku is controlled to 2.1 or more, as described above, variation in etching characteristics of the copper foil is suppressed, and the yield is excellent. A structure is realized.

According to the present invention, a printed wiring board excellent in yield can be provided.

The above-described object and other objects, features, and advantages will be further clarified by a preferred embodiment described below and the following drawings attached thereto.

It is sectional drawing which shows typically an example of the manufacturing method of the printed wiring board of 1st Embodiment. It is sectional drawing which shows typically a part of printed wiring board of this Embodiment. It is sectional drawing which shows typically the printed wiring board for demonstrating the skirt remainder. It is a top view which shows typically the printed wiring board for demonstrating the effect of 1st Embodiment. It is sectional drawing for demonstrating the wiring shape of 1st Embodiment. It is sectional drawing which shows typically the modification of the wiring shape of 1st Embodiment. It is sectional drawing which shows typically an example of the manufacturing method of the printed wiring board of 2nd Embodiment. It is sectional drawing which shows typically an example of the manufacturing method of the printed wiring board of 2nd Embodiment. It is sectional drawing which shows typically the modification of the wiring shape of 2nd Embodiment. It is sectional drawing which shows typically an example of the manufacturing method of the printed wiring board of 3rd Embodiment. It is sectional drawing which shows typically an example of the manufacturing method of the printed wiring board of 3rd Embodiment. It is sectional drawing which shows typically an example of the manufacturing method of the printed wiring board of 3rd Embodiment. It is sectional drawing which shows typically the modification of the manufacturing method of the printed wiring board of this Embodiment. It is a schematic diagram explaining Rp which is one of the parameters which show surface roughness. It is a schematic diagram explaining Rku which is one of the parameters which show surface roughness. It is a figure which shows the SEM image of an Example and a comparative example. It is a figure which shows the SEM image of an Example and a comparative example.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all the drawings, the same reference numerals are given to the same components, and the description will be omitted as appropriate.

(First embodiment)
FIG. 1 is a cross-sectional view illustrating a process procedure of a method for manufacturing a printed wiring board according to the first embodiment. Hereinafter, after describing the outline of the manufacturing method of the printed wiring board of 1st Embodiment, the effect of this manufacturing method is demonstrated. Detailed manufacturing conditions, materials, and the like of the first embodiment will be described later in the column of the second embodiment.

The printed wiring board manufacturing method according to the first embodiment includes a laminated board (copper with carrier foil) in which a copper foil with a carrier base material (copper foil layer 104) is laminated on at least one surface 30 of the insulating layer 102. A step of separating the carrier substrate (carrier foil layer 106) from the tension laminate 10), a step of selectively or selectively forming a metal layer 115 thicker than the copper foil layer 104 on the copper foil layer 104, Etching at least the copper foil layer 104 to obtain a pattern of the conductive circuit 119 composed of the copper foil layer 104 and the metal layer 115. After the process of obtaining the pattern of the conductive circuit 119 in this manufacturing process, when measured according to JIS B0601, Rp on the one surface 30 of the insulating layer 102 is 4.5 μm or less and Rku is 2.1 or more.

That is, the process of the printed wiring board manufacturing method of the first embodiment includes the following processes. First, as shown to Fig.1 (a), the copper clad laminated board 10 with carrier foil is prepared. In this copper clad laminate 10 with carrier foil, a carrier foil layer 106 is attached to both surfaces of the insulating layer 102 together with the copper foil layer 104. Subsequently, as shown in FIG. 1 (b), the carrier foil layer 106 is removed from the copper clad laminate 10 with the carrier foil by peeling off. Subsequently, as shown in FIG. 1C, a resist layer 112 having a predetermined opening pattern is formed on the remaining copper foil layer 104. A plating layer (metal layer 115) is formed by plating in the opening pattern of the resist layer 112 and on the copper foil layer 104 (FIG. 1D). Subsequently, as shown in FIG. 1E, the resist layer 112 is removed. Thereby, the pattern of the predetermined metal layer 115 can be selectively formed on the copper foil layer 104. Thereafter, as shown in FIG. 1F, the copper foil layer 104 formed on the one surface 30 of the insulating layer 102 is removed by, for example, soft etching in a region not covered with the metal layer 115. In the soft etching step, Rp on the one surface 30 of the insulating layer 102 is 4.5 μm or less, and Rku is 2.1 or more. After such a step of removing the copper foil layer 104, the pattern of the conductive circuit 119 can be formed by the remaining copper foil layer 104 and the metal layer 115. The printed wiring board 101 of this Embodiment is obtained by the above process (FIG. 1).

FIG. 2 is an enlarged sectional view of the conductive circuit 119 in the printed wiring board 101 according to the first embodiment. As shown in FIG. 2, printed wiring board 101 of the present embodiment is provided on insulating layer 102 and one surface 30 of insulating layer 102, and is a conductive circuit composed of copper foil layer 104 and metal layer 115. 119 patterns. The printed wiring board 101 is specified by Rp on the one surface 30 of the insulating layer 102 being 4.5 μm or less and Rku being 2.1 or more when measured according to JIS B0601.

Hereinafter, Rp indicating the maximum peak height of the roughness curve and Rku indicating the kurtosis (sharpness) of the roughness curve will be described with reference to FIGS. 14 and 15. These Rp and Rku are obtained by measuring the surface roughness of the one surface 30 of the insulating layer 102 according to JIS B0601 (2001) with no cut-off value. In the present embodiment, the roughness curve means a concavo-convex curve indicating the surface roughness. This roughness curve is obtained by a commercially available apparatus. In the present embodiment, in the drawing showing the unevenness of the surface (one surface 30) of the insulating layer 102, a portion corresponding to the concave portion means a trough and a portion corresponding to the convex portion means a mountain.

The maximum peak height Rp indicates the maximum value of the convex portion (Zpi) of the contour curve at the reference length lr, as shown in FIG. For this reason, reducing Rp means reducing the maximum height of the mountain on one surface 30 of the insulating layer 102. Therefore, by reducing Rp, the difference between the minimum height and the maximum height of the mountain can be reduced.

Further, the kurtosis Rku of the roughness curve indicates the sharpness of the mountain on the one surface 30 of the insulating layer 102 as shown in FIG. For this reason, increasing Rku means making the mountain a sharp angle on one surface 30 of the insulating layer 102. Therefore, by increasing Rku, the width of the mountain can be reduced and the interval between the peaks can be reduced. Rku is calculated by the following equation.

Here, lr: reference length, Z (x): rolling circle waviness curve, Rq: square root of roughness curve.

Conventionally, in the technical field to which the present invention belongs, the surface roughness is usually defined by an index called Ra or Rz (see, for example, Patent Document 1).
However, as a result of investigations by the present inventors, it has been found that these indexes do not sufficiently reflect the surface shape pattern of the base. For example, Ra is not an index that directly points to the maximum value of the height of the mountain, so even if the index Ra is controlled to be small, the maximum value of the height of the mountain can be increased. In the surface pattern of the base, the difference between the maximum value and the minimum value of the peak becomes large, and the height difference may occur on the surface of the copper foil formed thereon. On the other hand, Ra is an index that does not indicate the width of the peaks, and therefore, by controlling these indexes, the spacing between the peaks on the surface of the underlying insulating resin layer may be widened, thereby causing depressions in the conductor layer. Can occur.
As described above, in the conventional technology, even if such an index is controlled, it is difficult to sufficiently control the surface shape pattern of the base.
Therefore, the surface shape pattern of the conventional base may have a high crest and a wide crest interval, and the surface of the copper foil formed on the surface of the base having such a surface shape Since the surface shape varies, it has been difficult to stabilize the etching characteristics of the copper foil in the prior art.

As a result of further study, the present inventor has reduced the parameter Rp indicating the maximum height of the mountain in the underlying insulating layer 102 and increasing the parameter Rku indicating the sharpness of the mountain (the interval between the peaks is narrow). As a result, it has been found that the etching characteristics of the copper foil layer 104 (copper foil provided on the base) are improved, and the pattern of the conductive circuit 119 having a favorable wiring shape is formed.

Based on the above experimental facts, the present inventor made the following assumptions. That is, when there is a surface shape pattern on the surface of the underlying insulating layer 102 having a small crest height, a narrow crest interval, and an acute crest, etching of the copper foil layer 104 formed on the insulating layer 102 We thought that the variation in characteristics would be reduced.

Therefore, as a result of various experiments, when an index indicating that the height of the mountain is small and an index indicating that the interval between the peaks is narrow and an acute angle are controlled to appropriate values, Since the variation in etching characteristics of the formed copper foil has been reduced, the present inventor has determined, as such indexes, Rp indicating the maximum height of the mountain and Rku indicating the sharpness of the mountain (the interval between the peaks is narrow). And by controlling Rp to 4.5 μm or less and Rku to 2.1 or more, it becomes possible to appropriately control the surface shape pattern of one surface 30 of the insulating layer 102, and variation in etching characteristics of the copper foil As a result, the present invention has been completed.

In the present embodiment, for example, the number of peaks can be increased by forming a pattern having a narrow interval and an acute angle peak as the surface shape pattern. Thereby, since the area of the one surface 30 of the insulating layer 102 increases, the contact area of the insulating layer 102 and the copper foil layer 104 also increases. Thereby, it is possible to realize the printed wiring board 101 having excellent adhesion between the insulating layer 102 and the conductive circuit 119 including the copper foil layer 104.

Moreover, according to the method for manufacturing a printed wiring board of the present embodiment, it is possible to suppress the generation of streaks on one surface 30 of the insulating layer 102. Although this mechanism is not clear, a surface shape pattern with uniform crest height and crest spacing can be formed on one surface 30 of the insulating layer 102 as the surface shape pattern, so that the insulating layer 102 receives from the copper foil layer 104. It is presumed that the occurrence of streaks in the insulating layer 102 can be suppressed because the variation in stress in the horizontal direction is reduced.
Here, when streaks occur in the insulating layer 102, etching is excessive in order to remove residues (for example, etching residues) in the streaks, and the wiring shape may be deteriorated. On the other hand, when the etching amount is insufficient, streaks are generated. Residues inside cannot be removed, resulting in poor connection. Further, when streaks occur in the insulating layer 102, voids may occur in the multilayer wiring structure, and connection reliability may be reduced.
However, in the present embodiment, the generation of streaks can be suppressed as described above, so that it is possible to prevent a wiring shape defect, a connection defect, or a decrease in connection reliability due to such a streak.

In the present embodiment, the upper limit value of Rp on one surface 30 of the insulating layer 102 is 4.5 μm or less, more preferably 3.5 μm or less, and further preferably 2.5 μm or less. On the other hand, the lower limit of Rp is not particularly limited, but for example, is preferably 0.5 μm or more, more preferably 1.0 μm or more, and further preferably 1.5 μm or more. By setting Rp within the above range, defects such as etching residues at the time of fine wiring formation can be reduced, and a printed wiring board can be obtained with high yield. Furthermore, the insulation reliability between fine wiring circuits is excellent.

In the present embodiment, the upper limit value of Rku on one surface 30 of the insulating layer 102 is not particularly limited. For example, it is preferably 10 or less, more preferably 8 or less, and further preferably 6 or less. . On the other hand, the lower limit value of Rku is 2.1 or more, more preferably 3.0 or more, and further preferably 3.5 or more. By setting Rku within the above range, the surface of the base becomes fine irregularities, and the etching characteristics of the copper foil layer 104 formed thereon are uniform. Therefore, the side etching characteristics of the conductor layer such as the copper foil layer 104 can be made uniform. Moreover, since a contact area increases, adhesiveness with a conductor layer improves. Therefore, the printed wiring board 101 of this embodiment is excellent in heat resistance and insulation reliability between fine wirings.

Here, a favorable wiring shape will be described with reference to FIGS. In FIG. 4, the copper clad laminate 1 has an insulating layer 2, a copper foil layer 4, and a metal layer 14. First, a good wiring shape refers to a shape that is specified by the characteristic that there is less skirt residue compared to the conventional case. As shown in FIG. 4, the skirt remainder is formed by protruding the copper foil layer 4 in a region outside the metal layer 14 in the width direction orthogonal to the extending direction of the metal layer 14 in plan view. Say part. The determination as to whether or not the tail remains has been described with reference to FIGS. As shown in these drawings, for example, when viewed in cross section, the maximum width of the copper foil layer 104 (4) in the width direction is L1, and the minimum width of the metal layer 115 (14) in the width direction is L2. , L2−L1 = ΔL is larger than 0, it is determined that the tail remains. In such a case, in the conductive circuit 119 in this embodiment, ΔL only needs to be smaller than that of the conventional circuit, more preferably, L1 and L2 are the same (FIG. 2A), and more preferably L1 is It is smaller than L2. When L1 is smaller than L2, the copper foil layer 104 in a cross-sectional view has a region in which the width in the planar direction of the copper foil layer 104 is smaller than the width in the planar direction of the metal layer 115 (FIG. 2B). Such a shape of the conductive circuit 119 specified by L1 and L2 can be said to be a good wiring shape.

Moreover, the favorable wiring shape in this Embodiment refers to what the shape of the metal layer 115 is specified by the characteristic that the desired shape is maintained (FIG. 2A and FIG. 2). (B)). The desired shape here means a shape as designed, for example, a square shape or the like. Even when L1 is the same as L2, and L1 is smaller than L2, the etching characteristics of the copper foil layer 104 are improved, and thus such a shape can be realized.

Further, the cross-sectional shape of the copper foil layer 104 may be a rectangular shape having the same width as the metal layer 115 as shown in FIG. 2A, or may be an inversely tapered shape as shown in FIG. Good. The reverse taper-shaped copper foil layer 104 may have a surface area that decreases from the first surface (upper surface 20) to the second surface (lower surface 22) in plan view (however, due to variations in the manufacturing process). , Irregularities may be formed on a part of the side surface 24). Further, as shown in FIG. 5, in a cross-sectional view in the width direction, an angle θ (a counterclockwise angle) formed between a perpendicular to the insulating layer 102 and the side surface 24 is, for example, preferably 0 degrees or more and 20 degrees or less, More preferably, it is 1 degree or more and 10 degrees or less.

Further, the shape of the other copper foil layer 104 may be a kamaboko shape shown in FIG. 6 (a) or a constricted shape shown in FIG. 6 (b). By using the copper foil layer 104 having such a shape, L1 can be made smaller than L2 in the conductive circuit 119, and more than a certain contact area with the insulating layer 102 is ensured as compared with the reverse tapered shape. It is also possible.

In the printed wiring board of the present embodiment, it will be described with reference to FIG. 4 that the line and space (hereinafter referred to as L / S) controllability is excellent.
The space S2 and the space S1 illustrated in FIG. 4 indicate the distance between the adjacent

conductive circuits

19 and 119 in the width direction perpendicular to the direction in which the

conductive circuits

19 and 119 extend. .
In the conventional method for manufacturing a printed wiring board, the etching characteristics of the copper foil layer 4 vary, and the bottom of the copper foil layer 4 and the etching residue may occur. In order to always separate and electrically separate the copper foil layer 4, it is necessary to secure a sufficient space S2 as shown in FIG. In other words, the space S2 needs to be adjusted according to the variation of L1. In the conventional printed wiring board manufacturing method, since the controllability of L1 / S2 is low, it is difficult to form fine wiring.

On the other hand, in the method for manufacturing a printed wiring board according to the present embodiment, the etching characteristics of the copper foil layer 104 can be improved, so that the width of the metal layer 115 is maintained while maintaining the desired shape. The width of the copper foil layer 104 can be controlled. For this reason, L1 can be made equal to or less than L2 (that is, since there is no remaining skirt), the space S1 can be determined by the minimum width L2 of the metal layer 115. As described above, L2 can be a value as designed. Therefore, in the method for manufacturing a printed wiring board according to the present embodiment, the controllability of L2 / S1 is excellent. Therefore, since the L / S controllability is excellent, it is possible to obtain a method for manufacturing a printed wiring board capable of fine wiring processing while suppressing connection failure.

In the present embodiment, the etching on the side surface 24 in the copper foil layer 104 is referred to as side etching. In this side etching, etching proceeds in the horizontal direction with respect to the upper surface of the insulating layer 102.
On the other hand, etching on the upper surface 20 of the copper foil layer 104 is referred to as vertical etching. In this vertical etching, etching proceeds in a direction perpendicular to the upper surface of the insulating layer 102.

(Second Embodiment)
Hereinafter, a method for manufacturing a printed wiring board according to the second embodiment will be described. In the second embodiment, detailed manufacturing conditions, materials, and the like omitted in the first embodiment will be exemplified.

In the method of manufacturing a printed wiring board according to the second embodiment, the step of forming the metal layer 116 on the entire surface or selectively penetrates the copper clad laminate 100 composed of the copper foil layer 104 and the insulating layer 102. The step of forming the through-hole 108, the step of bringing the chemical solution into contact with at least the inner wall of the through-hole 108, and the non-electrolytic plating are used to electrically connect the copper foil layer 104 on the upper surface and the back surface of the insulating layer 102. The point which further includes the process of forming the electroplating layer 110 differs from 1st Embodiment.
7 and 8 are cross-sectional views showing process steps of the method for manufacturing a printed wiring board according to the second embodiment.

First, as shown in FIG. 7A, a copper clad laminate 10 with a carrier foil is prepared in which a copper foil layer 104 is bonded to both surfaces of an insulating layer 102 together with a carrier foil layer 106.

As the copper clad laminate 10 with carrier foil, for example, a peelable carrier foil layer 106 is laminated on at least one surface of the copper clad laminate 100. This copper clad laminate 100 is hereinafter referred to as a laminate. Although not particularly limited, for example, a laminate in which a copper foil layer 104 is laminated on at least one surface of an insulating layer 102 having an insulating resin layer containing a substrate can be used (in the figure, a fiber substrate is used). (Omitted). The laminated plate may be a single layer or may have a multilayer structure. That is, as a laminated board, you may be comprised only by the core layer, However, You may use what has the buildup layer formed on the core layer. As such a laminated plate, a known one can be applied, for example, a laminate of a plurality of prepregs can be used. Although this prepreg is not specifically limited, For example, it obtains by methods, such as impregnating base materials, such as glass cloth, with the resin composition containing a thermosetting resin, a hardening | curing agent, a filler, etc. And as a laminated board, what superposed | stacked the ultra-thin metal foil with a carrier foil on at least one surface and heat-press-molded etc. can be used. Moreover, the same material as that of the core layer may be used for the interlayer insulating layer of the buildup layer, but the base material or the resin composition may be different. In the present embodiment, the insulating layer 102 corresponds to an insulating resin layer that constitutes a core layer or a buildup layer. An example of using a laminate having a buildup layer will be described later in the third embodiment.

As the resin composition constituting the laminate and the interlayer insulating layer used in the present embodiment, a known resin used as an insulating material of a printed wiring board (hereinafter also referred to as an insulating resin composition) can be used. Usually, thermosetting resins having good heat resistance and chemical resistance are mainly used. The resin composition is not particularly limited, and is preferably a resin composition containing at least a thermosetting resin.

Examples of thermosetting resins include urea (urea) resins, melamine resins, maleimide resins, polyurethane resins, unsaturated polyester resins, resins having a benzoxazine ring, bisallyl nadiimide compounds, vinyl benzyl resins, vinyl benzyl ether resins. Benzocyclobutene resin, cyanate resin, epoxy resin and the like. Among these, the curable resin is preferably a combination having a glass transition temperature of 200 ° C. or higher. For example, spiro ring-containing, heterocyclic, trimethylol type, biphenyl type, naphthalene type, anthran type, novolak type bifunctional or trifunctional epoxy resin, cyanate resin (including cyanate resin prepolymer), maleimide resin, It is preferable to use a benzocyclobutene resin or a resin having a benzoxazine ring. When using an epoxy resin and / or a cyanate resin, the linear expansion is reduced and the heat resistance is remarkably improved. In addition, combining epoxy resin and / or cyanate resin with a high amount of fillers has the advantage of excellent flame retardancy, heat resistance, impact resistance, high rigidity, and electrical properties (low dielectric constant, low dielectric loss tangent) There is. Here, the improvement in heat resistance is that the glass transition temperature becomes 200 ° C. or higher after the curing reaction of the thermosetting resin, the thermal decomposition temperature of the cured resin composition increases, and the reaction at 250 ° C. or higher. This is considered to result from the reduction of low molecular weight such as residues. Furthermore, the improvement in flame retardancy is due to the fact that the benzene ring is easily carbonized (graphitized) and a carbonized portion is generated because of the high proportion of the benzene ring due to its structure due to the aromatic thermosetting resin. It is thought to be caused.

The resin composition may further contain a flame retardant as long as the effects of the present invention are not impaired, but a non-halogen flame retardant is preferred from the environmental aspect. Examples of the flame retardant include an organic phosphorus flame retardant, an organic nitrogen-containing phosphorus compound, a nitrogen compound, a silicone flame retardant, and a metal hydroxide. Examples of organophosphorus flame retardants include phosphine compounds such as HCA, HCA-HQ, and HCA-NQ manufactured by Sanko Co., Ltd., and phosphorus-containing benzoxazine compounds such as HFB-2006M manufactured by Showa Polymer Co., Ltd. Phosphoric acid ester compounds such as PPQ manufactured by Clariant Co., Ltd., OP930 manufactured by Clariant Co., Ltd., PX200 manufactured by Daihachi Chemical Co., Ltd., phosphorus-containing epoxy resins such as FX289 and FX310 manufactured by Toto Kasei Co., Ltd. Examples thereof include phosphorus-containing phenoxy resins such as ERF001 manufactured by Co., Ltd. Examples of organic nitrogen-containing phosphorus compounds include phosphate ester amide compounds such as SP670 and SP703 manufactured by Shikoku Kasei Kogyo Co., Ltd., SPB100 and SPE100 manufactured by Otsuka Chemical Co., Ltd., and FP-series manufactured by Fushimi Seisakusho Co., Ltd. And phosphazene compounds. Examples of the metal hydroxide include magnesium hydroxide such as UD650 and UD653 manufactured by Ube Materials Co., Ltd., CL310 manufactured by Sumitomo Chemical Co., Ltd., aluminum hydroxide such as HP-350 manufactured by Showa Denko Co., Ltd., and the like. It is done.

Examples of the epoxy resin used in the resin composition 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 resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, etc. novolac type epoxy resin, biphenyl type epoxy resin, xylylene type epoxy resin, biphenyl aralkyl type epoxy resin, etc. aryl alkylene type epoxy resin , Naphthol type epoxy resin, naphthalene diol type epoxy resin, bifunctional to tetrafunctional epoxy type naphthalene resin, naphthylene ether type epoxy Naphthalene-type epoxy resins such as Si resin, binaphthyl-type epoxy resin, naphthalene-aralkyl-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 etc. are mentioned.

As the epoxy resin, one of these may be used alone, or two or more having different weight average molecular weights may be used in combination. Moreover, you may use together 1 type, or 2 or more types of these, and those prepolymers.

Among these epoxy resins, aryl alkylene type epoxy resins are particularly preferable. Thereby, moisture-absorbing solder heat resistance and flame retardance can be further improved.

The arylalkylene type epoxy resin refers to an epoxy resin having one or more arylalkylene groups in a repeating unit. For example, a xylylene type epoxy resin, a biphenyl dimethylene type epoxy resin, etc. are mentioned. Among these, a biphenyl dimethylene type epoxy resin is preferable. A biphenyl dimethylene type | mold epoxy resin can be shown, for example by following General formula (1). Examples of the biphenyl dimethylene type epoxy resin include NC-3000, NC-3000L, and NC-3000-FH manufactured by Nippon Kayaku Co., Ltd.

The average repeating unit n of the biphenyl dimethylene type epoxy resin represented by the general formula (1) is an arbitrary integer. The lower limit of n is not particularly limited, but is preferably 1 or more, and particularly preferably 2 or more. When n is too small, the biphenyl dimethylene type epoxy resin is easily crystallized, and the solubility in a general-purpose solvent is relatively lowered, which may make handling difficult. The upper limit of n is not particularly limited, but is preferably 10 or less, and particularly preferably 5 or less. If n is too large, the fluidity of the resin is lowered, which may cause molding defects.

As the epoxy resin other than the above, a novolac type epoxy resin having a condensed ring aromatic hydrocarbon structure is preferable. Thereby, heat resistance and low thermal expansibility can further be improved.

The novolak 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, and 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 novolac-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, 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-dihydroxynaphtha And naphthalenediols such as 2,7-dihydroxynaphthalene, polyphenols such as resorcin, catechol, hydroquinone, pyrogallol, and fluoroglucin, and alkyl polyhydric phenols 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, but for example, naphthalene derivatives such as methoxynaphthalene and butoxynaphthalene, anthracene derivatives such as methoxyanthracene, phenanthrene derivatives such as methoxyphenanthrene, other tetracene derivatives, chrysene derivatives, pyrene derivatives Derivatives such as triphenylene and tetraphen derivatives are mentioned.

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, and methoxynaphthalene-modified novolak epoxy resin Etc. Among these, a novolac type epoxy resin having a condensed ring aromatic hydrocarbon structure represented by the following formula (2) is preferable. An example of the novolak type epoxy resin having a condensed ring aromatic hydrocarbon structure is HP-5000 manufactured by DIC Corporation.

(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, It is a group selected from an aryl group such as a benzyl group and an organic group containing 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 (2) is a structure represented by (Ar1) to (Ar4) in formula (3), and R in formula (3) 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 or a halogen element, an aryl group such as 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, heat resistance and low thermal expansibility can further be improved. In addition, since the naphthalene ring has a higher π-π stacking effect than the 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 change in heat shrinkage before and after reflow is small.
The naphthol type epoxy resin can be represented, for example, by the following general formula (4-1). Examples of the naphthol type epoxy resin include ESN-375 manufactured by Nippon Steel Chemical Co., Ltd.
The naphthalene diol type epoxy resin can be represented by, for example, the following formula (4-2). An example of the naphthalene diol type epoxy resin is HP-4032D manufactured by DIC Corporation.
The bifunctional to tetrafunctional epoxy type naphthalene resin can be represented by, for example, the following formulas (4-3) (4-4) (4-5). Examples of the bifunctional to tetrafunctional epoxy type naphthalene resins include HP-4700 and HP-4770 manufactured by DIC Corporation.
The naphthylene ether type epoxy resin can be represented by, for example, the following general formula (4-6). Examples of the naphthylene ether type epoxy resin include HP-6000 manufactured by DIC Corporation.

(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.)

(Wherein R ¹ represents a hydrogen atom or a methyl group, and 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 at least one of o and m is 1 or more.)

The cyanate resin used in the resin composition can be obtained, for example, by reacting a cyanogen halide compound with phenols. Specific examples of the cyanate resin include novolak-type cyanate resins such as phenol novolak-type cyanate resins and cresol novolak-type cyanate resins, naphthol aralkyl-type cyanate resins, dicyclopentadiene-type cyanate resins, biphenyl-type cyanate resins, and bisphenol A-type cyanate resins. And bisphenol type cyanate resins such as bisphenol AD type cyanate resin and tetramethyl bisphenol F type cyanate resin.

Among these, it is particularly preferable to include a novolak type cyanate resin, a naphthol aralkyl type cyanate resin, a dicyclopentadiene type cyanate resin, and a biphenyl type cyanate resin. Furthermore, the resin composition preferably contains 10% by weight or more of this cyanate resin in the total solid content of the resin composition. Thereby, the heat resistance (glass transition temperature, thermal decomposition temperature) of a prepreg can be improved. Further, the thermal expansion coefficient of the prepreg (particularly, the thermal expansion coefficient in the thickness direction of the prepreg) can be reduced. When the thermal expansion coefficient in the thickness direction of the prepreg is lowered, the stress strain of the multilayer printed wiring can be reduced. Furthermore, in a multilayer printed wiring board having fine interlayer connection portions, the connection reliability can be greatly improved.

Among the novolak-type cyanate resins used in the resin composition, a novolak-type cyanate resin represented by the following formula (5) is preferable. A novolac type cyanate resin represented by the formula (5) having a weight average molecular weight of 2000 or more, more preferably 2,000 to 10,000, still more preferably 2,200 to 3,500, and a weight average molecular weight of 1500 or less, more Preferably, it is preferably used in combination with a novolak-type cyanate resin represented by the formula (5) of 200 to 1,300 (hereinafter, “to” represents that it includes an upper limit value and a lower limit value unless otherwise specified). ). In the present embodiment, the weight average molecular weight is a value measured by a gel-permeation chromatography method in terms of polystyrene.

In formula (5), n represents an integer of 0 or more.

Also, as the cyanate resin, a cyanate resin represented by the following general formula (6) is also preferably used. Cyanate resins represented by the following general formula (6) include naphthols such as α-naphthol and β-naphthol, p-xylylene glycol, α, α'-dimethoxy-p-xylene, 1,4-di (2- It is obtained by condensing naphthol aralkyl resin obtained by reaction with hydroxy-2-propyl) benzene and cyanic acid. In the general formula (6), n is 1 or more, but is more preferably 10 or less. When n is 10 or less, the resin viscosity is not high, the impregnation property to the base material is good, and the deterioration of the performance as a laminate can be suppressed. In addition, intramolecular polymerization is unlikely to occur at the time of synthesis, and the liquid separation property at the time of washing with water is improved, so that a decrease in yield can be prevented.

In formula (6), R represents a hydrogen atom or a methyl group, R may be the same or different, and n represents an integer of 1 or more.

Also, as the cyanate resin, a dicyclopentadiene type cyanate resin represented by the following general formula (7) is also preferably used. In the dicyclopentadiene type cyanate resin represented by the following general formula (7), n in the following general formula (7) is more preferably 0 or more and 8 or less. When n is 8 or less, the resin viscosity is not high, the impregnation property to the base material is good, and the deterioration of the performance as a laminate can be suppressed. Moreover, by using a dicyclopentadiene type cyanate resin, it is excellent in low hygroscopicity and chemical resistance.

n represents an integer of 0 to 8.

Moreover, the resin composition may further contain a curing accelerator. For example, if the thermosetting resin is an epoxy resin or a cyanate resin, a curing accelerator for phenol resin, epoxy resin, or cyanate resin can be used. The phenol resin is not particularly limited. For example, a phenol novolak resin, a cresol novolak resin, a bisphenol A novolak resin, an arylalkylene type novolak resin or the like novolak type phenol resin, an unmodified resole phenol resin, tung oil, linseed oil, walnut oil Examples thereof include resol type phenol resins such as oil-modified resol phenol resins modified with the above. As said phenol resin, a phenol novolak or a cresol novolak resin is preferable. Among these, biphenyl aralkyl-modified phenol novolac resin is preferable from the viewpoint of moisture absorption solder heat resistance.
One of these can be used alone, or two or more having different weight average molecular weights can be used in combination, or one or two or more of these prepolymers can be used in combination.

The curing accelerator is not particularly limited. For example, organic metals such as zinc naphthenate, cobalt naphthenate, tin octylate, cobalt octylate, bisacetylacetonate cobalt (II), and trisacetylacetonate cobalt (III) Salts, tertiary amines such as triethylamine, tributylamine, diazabicyclo [2,2,2] octane, 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-ethyl-4-ethylimidazole 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 2-undecylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 2-phenyl- 4-methyl Imidazoles such as 5-hydroxyimidazole, 2-phenyl-4,5-dihydroxyimidazole, 2,3-dihydro-1H-pyrrolo (1,2-a) benzimidazole, phenolic compounds such as phenol, bisphenol A, nonylphenol, Examples include acetic acid, benzoic acid, salicylic acid, organic acids such as p-toluenesulfonic acid, onium salt compounds, and the like, or mixtures thereof. One of these can be used alone, including derivatives thereof, or two or more of these can be used in combination.

The thermosetting resin may contain a maleimide compound from the viewpoint of heat resistance. The maleimide compound is not particularly limited as long as it is a compound having one or more maleimide groups in one molecule. Specific examples thereof include N-phenylmaleimide, N-hydroxyphenylmaleimide, bis (4-maleimidophenyl) methane, 2,2-bis {4- (4-maleimidophenoxy) -phenyl} propane, bis (3,5 -Dimethyl-4-maleimidophenyl) methane, bis (3-ethyl-5-methyl-4-maleimidophenyl) methane, bis (3,5-diethyl-4-maleimidophenyl) methane, polyphenylmethanemaleimide, these maleimide compounds Or a prepolymer of a maleimide compound and an amine compound.

The thermosetting resin may contain a phenoxy resin, a polyvinyl alcohol resin, a polyimide, a polyamide, a polyamideimide, a polyethersulfone resin, or a polyphenylene ether resin from the viewpoint of adhesion to the metal foil. Good.

Examples of the phenoxy resin include a phenoxy resin having a bisphenol skeleton, a phenoxy resin having a naphthalene 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. Thereby, the glass transition temperature of the phenoxy resin can be increased due to the rigidity of the biphenyl skeleton, and the adhesion between the phenoxy resin and the metal can be improved due to the presence of the bisphenol S skeleton. As a result, the heat resistance of the insulating layer 102 can be improved, and the adhesion of the wiring portion (conductive circuit 118) to the insulating layer 102 can be improved when a multilayer substrate is manufactured. 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 to the insulating layer 102 of a wiring part can further be improved at the time of manufacture of a multilayer substrate.
Examples of commercially available phenoxy resins include FX280 and FX293 manufactured by Tohto Kasei Co., Ltd., YX8100, YX6954, YL6974, YL7482, YL7553, YL6794, YL7213, and YL7290 manufactured by Japan Epoxy Resin Co., Ltd. The molecular weight of the phenoxy resin is not particularly limited, but the weight average molecular weight is preferably 5,000 to 70,000, and more preferably 10,000 to 60,000.
When the phenoxy resin is used, its content is not particularly limited, but it is preferably 1 to 40% by weight, more preferably 5 to 30% by weight based on the entire resin composition.

Examples of commercially available polyvinyl alcohol resins include Denka Butylal 4000-2, 5000-A, 6000-C and 6000-EP manufactured by Denki Kagaku Kogyo Co., Ltd., S-Rec BH Series, BX Series, KS manufactured by Sekisui Chemical Co., Ltd. Series, BL series, BM series and the like. Particularly preferred are those having a glass transition temperature of 80 ° C. or higher.

Commercially available products of polyimide, polyamide and polyamideimide include “Vilomax HR11NN (registered trademark)” and “HR-16NN” and “HR15ET” manufactured by Toyobo Co., Ltd., and polyamide imide “KS-” manufactured by Hitachi Chemical Co., Ltd. 9300 "and the like. “Neoprim C-1210 (registered trademark)” manufactured by Mitsubishi Gas Chemical Co., Inc., soluble polyimide “Rika Coat SN20 (registered trademark)” and “Rika Coat PN20 (registered trademark)” manufactured by Shin Nippon Rika Co., Ltd., GE Plastics Examples include polyetherimide “Ultem (registered trademark)” manufactured by Co., Ltd., “V8000” and “V8002” and “V8005” manufactured by DIC Corporation, “BPAM155” manufactured by Nippon Kayaku Co., Ltd., and the like.

As a commercial item of polyethersulfone resin, a well-known thing can be used, for example, PES4100P, PES4800P, PES5003P, and PES5200P by Sumitomo Chemical Co., Ltd. can be mentioned.

Examples of polyphenylene ether resins include poly (2,6-dimethyl-1,4-phenylene) oxide, poly (2,6-diethyl-1,4-phenylene) oxide, and poly (2-methyl-6-ethyl-). 1,4-phenylene) oxide, poly (2-methyl-6-propyl-1,4-phenylene) oxide, poly (2,6-dipropyl-1,4-phenylene) oxide, poly (2-ethyl-6- And propyl-1,4-phenylene) oxide. Examples of commercially available products include Japanese G.P. E. “Noryl PX9701 (registered trademark)” (number average molecular weight Mn = 14,000), “Noryl 640-111 (registered trademark)” (number average molecular weight Mn = 25,000) manufactured by Plastic, and “SA202” manufactured by Asahi Kasei Corporation (Number average molecular weight Mn = 20,000) and the like, and these can be used by reducing the molecular weight by a known method.

Among these, reactive oligophenylene oxide having a terminal modified with a functional group is preferable. Thereby, compatibility with a thermosetting resin improves, and since the three-dimensional crosslinked structure between polymers can be formed, it is excellent in mechanical strength. For example, 2,2 ′, 3,3 ′, 5,5′-hexamethylbiphenyl-4,4′-diol-2,6-dimethylphenol polycondensate described in JP-A-2006-28111 and A reaction product with chloromethylstyrene is mentioned.
Such reactive oligophenylene oxide can be produced by a known method. Commercial products can also be used. For example, OPE-2st 2200 (manufactured by Mitsubishi Gas Chemical Co., Inc.) can be preferably used.
The weight average molecular weight of the reactive oligophenylene oxide is preferably 2,000 to 20,000, and more preferably 4,000 to 15,000. When the weight average molecular weight of reactive oligophenylene oxide exceeds 20,000, it becomes difficult to dissolve in a volatile solvent. On the other hand, when the weight average molecular weight is less than 2,000, the crosslink density becomes too high, which adversely affects the elastic modulus and flexibility of the cured product.

The amount of the thermosetting resin in the resin composition used in the present embodiment is not particularly limited as long as it is appropriately adjusted according to the purpose, but in the total solid content of the resin composition, the thermosetting resin is It is preferably 10 to 90% by weight, more preferably 20 to 70% by weight, still more preferably 25 to 50% by weight (hereinafter, “to” includes an upper limit value and a lower limit value unless otherwise specified). Represents that).

When an epoxy resin and / or cyanate resin is used as the thermosetting resin, the epoxy resin is preferably 5 to 50% by weight in the total solid content of the resin composition. 5 to 25% by weight is preferred. The total solid content of the resin composition is preferably 5 to 50% by weight of the cyanate resin, and more preferably 10 to 25% by weight of the cyanate resin.

It is preferable from the viewpoint of low thermal expansion and mechanical strength that the resin composition contains an inorganic filler. The inorganic filler is not particularly limited, but for example, silicates such as talc, fired clay, unfired clay, mica, glass, oxides such as titanium oxide, alumina, silica, fused silica, calcium carbonate, magnesium carbonate, hydrous Carbonates such as talcite, aluminum hydroxide, boehmite (AlO (OH)), boehmite commonly referred to as “pseudo” boehmite (ie, Al ₂ O ₃ .xH ₂ O, where x = 1 to 2), water Metal hydroxides such as magnesium oxide and calcium hydroxide, sulfates or sulfites such as barium sulfate, calcium sulfate, calcium sulfite, zinc borate, barium metaborate, aluminum borate, calcium borate, sodium borate, etc. Borate, aluminum nitride, boron nitride, silicon nitride, carbon nitride and other nitrides, titanic acid Strontium, and titanium salt such as barium titanate. One of these can be used alone, or two or more can be used in combination.

Among these, magnesium hydroxide, aluminum hydroxide, boehmite, silica, fused silica, talc, calcined talc, and alumina are preferable. Silica is particularly preferable in terms of low thermal expansion and insulation reliability, and spherical fused silica is more preferable. Moreover, aluminum hydroxide is preferable in terms of flame resistance. Moreover, in this Embodiment, since it is a base material which is easy to impregnate even if it is an inorganic filler, the quantity of an inorganic filler can be increased in the said resin composition. When the inorganic filler has a high concentration in the resin composition, the drill wearability is deteriorated, but when the inorganic filler is boehmite, the drill wearability is preferable.

The particle diameter of the inorganic filler is not particularly limited, but an inorganic filler having a monodispersed average particle diameter can be used, or an inorganic filler having a polydispersed average particle diameter can be used. Furthermore, one or two or more inorganic fillers having an average particle size of monodisperse and / or polydisperse may be used in combination. The average particle size of the inorganic filler is not particularly limited, but is preferably 0.1 μm to 5.0 μm, and particularly preferably 0.1 μm to 3.0 μm. If the particle size of the inorganic filler is less than the lower limit, the viscosity of the resin composition becomes high, which may affect workability during prepreg production. When the upper limit is exceeded, phenomena such as sedimentation of the inorganic filler may occur in the resin composition. The average particle diameter can be measured using a laser diffraction / scattering particle size distribution measuring device (manufactured by Shimadzu Corporation, general equipment such as SALD-7000).

The content of the inorganic filler is not particularly limited, but is preferably 10% by weight to 90% by weight, more preferably 30% by weight to 80% by weight, and even more 50% by weight in the total solid content of the resin composition. It is preferable that the amount be ˜75% by weight. In the case where the resin composition contains a cyanate resin and / or a prepolymer thereof, the content of the inorganic filler is preferably 50 to 75% by weight in the total solid content of the resin composition. If the inorganic filler content exceeds the above upper limit, the fluidity of the resin composition may be extremely poor, which may be undesirable, and if it is less than the lower limit, the strength of the insulating layer made of the resin composition is not sufficient, It may not be preferable.

The resin composition used in the present embodiment can also contain a rubber component. For example, preferable examples of the rubber particles that can be used in the present embodiment include core-shell type rubber particles and crosslinked acrylonitrile butadiene rubber particles. Cross-linked styrene butadiene rubber particles, acrylic rubber particles, silicone particles and the like.

The core-shell type rubber particles are rubber particles having a core layer and a shell layer. For example, a two-layer structure in which an outer shell layer is formed of a glassy polymer and an inner core layer is formed of a rubbery polymer, or Examples include a three-layer structure in which the outer shell layer is made of a glassy polymer, the intermediate layer is made of a rubbery polymer, and the core layer is made of a glassy polymer. The glassy polymer layer is made of, for example, a polymer of methyl methacrylate, and the rubbery polymer layer is made of, for example, a butyl acrylate polymer (butyl rubber). Specific examples of the core-shell type rubber particles include Staphyloid AC3832, AC3816N (trade name, manufactured by Ganz Kasei Co., Ltd.), and Metabrene KW-4426 (trade name, manufactured by Mitsubishi Rayon Co., Ltd.). Specific examples of the crosslinked acrylonitrile butadiene rubber (NBR) particles include XER-91 (average particle size 0.5 μm, manufactured by JSR Corporation).

Specific examples of the crosslinked styrene butadiene rubber (SBR) particles include XSK-500 (average particle diameter 0.5 μm, manufactured by JSR Corporation). Specific examples of the acrylic rubber particles include methabrene W300A (average particle size 0.1 μm), W450A (average particle size 0.2 μm) (manufactured by Mitsubishi Rayon Co., Ltd.), and the like.

The silicone particles are not particularly limited as long as they are rubber elastic fine particles formed of organopolysiloxane. For example, fine particles made of silicone rubber (organopolysiloxane crosslinked elastomer) itself, and a core portion made of silicone mainly composed of two-dimensional crosslinking. Examples thereof include core-shell structured particles coated with silicone mainly composed of a three-dimensional crosslinking type. Silicone rubber fine particles include KMP-605, KMP-600, KMP-597, KMP-594 (manufactured by Shin-Etsu Chemical Co., Ltd.), Trefil E-500, Trefil E-600 (manufactured by Toray Dow Corning Co., Ltd.), etc. Commercial products can be used.

The above resin composition may further contain a coupling agent. The coupling agent improves the wettability of the interface between the thermosetting resin and the inorganic filler, thereby uniformly fixing the resin and the inorganic filler to the base material, and heat resistance, particularly solder heat resistance after moisture absorption. In order to improve the properties.

Although the said coupling agent is not specifically limited, For example, an epoxy silane coupling agent, a cationic silane coupling agent, an aminosilane coupling agent, a titanate coupling agent, a silicone oil type coupling agent etc. are mentioned. Thereby, the wettability with the interface of an inorganic filler can be made high, and thereby heat resistance can be improved more.
The addition amount of the coupling agent is not particularly limited, but is preferably 0.05 to 3% by weight, particularly preferably 0.1 to 2% by weight, based on 100% by weight of the inorganic filler. If the content is less than the lower limit, the inorganic filler cannot be sufficiently coated, and thus the effect of improving the heat resistance may be reduced. If the content exceeds the upper limit, the reaction is affected, and the bending strength is reduced. There is a case.

The resin composition used in the present embodiment includes an antifoaming agent, a leveling agent, an ultraviolet absorber, a foaming agent, an antioxidant, a flame retardant, a flame retardant aid such as silicone powder, and an ion scavenger as necessary. You may add additives other than the said components, such as.

The above resin composition preferably contains at least an epoxy resin, a cyanate resin, and an inorganic filler, from the viewpoint of easily realizing low linear expansion, high rigidity, and high heat resistance of the prepreg. Among them, the solid content of the resin composition preferably contains 5 to 50% by weight of epoxy resin, 5 to 50% by weight of cyanate resin, and 10 to 90% by weight of inorganic filler, and further contains 5 to 50% of epoxy resin. Preferably, it contains ˜25 wt%, cyanate resin 10˜25 wt%, and inorganic filler 30˜80 wt%.

The prepreg used in the present embodiment is obtained by impregnating or coating a base material with a varnish of a resin composition. As the base material, well-known ones used for various types of laminates for electrical insulating materials are used. Can be used. Examples of the material of the substrate include inorganic fibers such as E glass, D glass, T glass, S glass, and Q glass, organic fibers such as polyimide, polyester, and tetrafluoroethylene, and mixtures thereof. These base materials have shapes such as woven fabric, non-woven fabric, low-ink, chopped strand mat, surfacing mat, etc., and the material and shape are selected depending on the intended use and performance of the molded product, and can be used alone or as required. It can be used from more than a variety of materials and shapes. The thickness of the base material is not particularly limited, but usually about 0.01 to 0.5 mm is used, and the surface is treated with a silane coupling agent or the like, or mechanically opened and flattened. These are suitable in terms of heat resistance, moisture resistance and processability. The prepreg is usually impregnated or coated with a resin so that the resin content is 20 to 90% by weight after drying, and is heated and dried at a temperature of 120 to 220 ° C. for 1 to 20 minutes. A semi-cured state (B stage state) can be obtained. Furthermore, a laminated sheet can be obtained by laminating 1 to 20 sheets of this prepreg and laminating them by heating and pressing in a configuration in which an ultrathin copper foil with a carrier foil is disposed on both sides thereof. The thickness of the plurality of prepreg layers varies depending on the application, but a thickness of 0.03 to 2 mm is usually preferable. As a laminating method, a normal laminating method can be applied. For example, a multistage press, a multistage vacuum press, continuous molding, an autoclave molding machine or the like is used, and the temperature is usually 100 to 250 ° C., the pressure is 0.2 to 10 MPa, and the heating time is used. Lamination can be performed under conditions of 0.1 to 5 hours, or lamination can be performed under conditions of lamination conditions of 50 to 150 ° C., 0.1 to 5 MPa, and vacuum pressure of 1.0 to 760 mmHg using a vacuum laminating apparatus.

Also, the ultrathin copper foil with a carrier foil (copper foil layer 104) used in the present embodiment is said to be a bumpy electrodeposit layer (yake plating) on the roughened surface of the ultrathin foil. The surface is roughened by the formation, oxidation treatment, reduction treatment, etching or the like. Therefore, the surface roughness of the roughened surface of the ultrathin copper foil used in the present embodiment preferably has an upper limit of 10-point average roughness (Rz) shown in JIS B0601 of 5.0 μm or less. The lower limit is not particularly limited, but is preferably 0.1 μm or more. Furthermore, the arithmetic average roughness (Ra) is preferably 1.0 μm or less, and more preferably 0.5 μm or less.

Further, in the present embodiment, as the copper foil layer 104, copper containing an additive metal component such as nickel or aluminum in addition to copper foil made of copper (excluding contaminants inevitably mixed in the manufacturing process) is used. Foil may be used (in this case, the copper content is not particularly limited, but is preferably 90% by weight or more, more preferably 95% by weight or more based on the total weight of all metal components constituting the copper foil layer 104). It is preferably 99% by weight or more, and the additive metal component may be used alone or in combination of two or more. Further, instead of the copper foil layer 104, a metal foil such as a nickel foil or an aluminum foil may be used.

As a conventional method for forming a copper foil, a copper foil having a thickness of about 30 μm is usually formed on the electrode by plating. However, in this formation method, the copper foil sometimes takes over the orientation of the lower metal layer (for example, electrode), and it is difficult to produce a copper foil having a desired crystal plane. Moreover, when the film thickness of the copper foil is thick, for example, when it is 30 μm or more, the crystal grains tend to be coarsened in the thickness direction.

In contrast, in the method for forming the copper foil layer 104 of the present embodiment, a release layer is formed on the electrode, and the copper foil layer 104 is formed on the release layer. For this reason, it can suppress that the copper foil layer 104 takes over the orientation of the lower layer electrode. In other words, by appropriately controlling the orientation on one surface of the copper foil layer 104 in contact with the release layer, the crystal plane of the copper foil layer 104 constitutes a layer, so that the orientation on one surface can be inherited to the other surface. It becomes possible. Thereby, the copper foil layer 104 having a desired orientation can be formed.

The film thickness of the copper foil layer 104 is not particularly limited, but is preferably 0.1 μm or more and 5 μm or less, and more preferably 0.5 μm or more and 3 μm or less. By setting the film thickness of the copper foil layer 104 within such a range, the grain sizes of the crystal grains of the copper foil layer 104 can be made uniform. Thereby, it can suppress that the orientation changes in the film thickness direction of the copper foil layer 104.

Thus, the orientation on the upper surface 20 of the copper foil layer 104 can be controlled. For example, the ratio of crystal planes (ie, the orientation) is the same from the lower surface 22 to the upper surface 20 of the copper foil layer 104, for example, XRD. The ratio of the plane orientation (200) measured by the thin film method, or the ratio of the plane orientation (200) and the plane orientation (220) can be made the same. Here, the same means that a slight difference in the manufacturing process is allowed. For example, the ratio of the plane orientation (200) on the lower surface 22 of the copper foil layer 104 is ± 5 of the ratio of the plane orientation (200) on the upper surface 20. Means within%. Therefore, it can be said that the ratio of the plane orientation of the lower surface 22 of the copper foil layer 104 measured by the XRD thin film method is equivalent to the ratio of the upper surface of the copper foil layer 104.

In addition, also on the upper surface 20 of the copper foil layer 104 after the copper-clad laminate 100 is formed by heat and pressure molding, the orientation is determined by the copper foil layer (copper foil with peelable carrier foil) before heat and pressure molding. ) Value is maintained. The conditions for the heat and pressure molding here are, for example, 1 hour at 200 ° C. and a pressure of 3 MPa. The reason why the ratio is maintained in this way is not clear, but it is presumed that the average grain size of the crystal grains in the copper foil layer 104 is small and that the average grain size is uniform to a certain extent.
Therefore, the ratio of the plane orientation (200) on the upper surface 20 of the copper foil layer 104 (that is, the contact surface with the metal layer 116 (for example, the electroless plating layer 110)) also before and after the etching process of the copper foil layer 104 described later. Alternatively, it can be said that the ratio of the plane orientation (200) and the plane orientation (220) is the same.

The copper foil layer 104 of the present embodiment preferably has crystal grains having an average long side length of 2 μm or less. The shape of the crystal grains in the copper foil layer 104 is, for example, a columnar shape or a triangular pyramid shape. For this reason, the maximum length of the crystal grains of the copper foil layer 104 is a long side in a cross-sectional view. The average length of this long side is about 10,000 to 10,000 times using FIB-SIM (Focused Ion Beam Scanning Ion Microscope) or FIB-SEM (Focused Ion Beam Scanning Electron Microscope). An average is calculated from cross-sectional images of 10 μm and 10 μm in width, and is calculated as an average value of a total of three field images. Thereby, the etching characteristics of the copper foil layer 104 are improved.

In the copper foil layer 104 of the present embodiment, the area ratio occupied by crystal grains having an average long side length of 2 μm or less in a cross-sectional view is preferably 80% or more, more preferably 85% or more. More preferably, it is 90% or more. This area ratio is calculated as an average value of a total of three fields of view by performing image processing on the field of view of the cross-sectional image as described above. Thereby, the etching characteristics of the copper foil layer 104 are improved.

Here, a detailed method of forming a peelable type copper foil used for the copper foil layer 104 will be described.
The method for producing the copper foil used in the present embodiment is not particularly limited. For example, in the case of producing a peelable type copper foil having a carrier, a metal that becomes a release layer on a carrier foil having a thickness of 10 to 50 μm, etc. An inorganic compound or organic compound layer is formed, and a copper foil is formed on the release layer by plating. As the conditions for the plating treatment, for example, when a copper sulfate bath is used, sulfuric acid 50 to 100 g / L, copper 30 to 100 g / L, liquid temperature 20 ° C. to 80 ° C., current density 0.5 to 100 A / dm. ^{When a} copper pyrophosphate bath is used, potassium pyrophosphate 100-700 g / L, copper 10-50 g / L, liquid temperature 30 ° C.-60 ° C., pH 8-12, current density 1-10 A / Dm ² condition. Further, various additives may be added to the bath in consideration of the physical properties and smoothness of the copper foil. Note that the peelable type metal foil is a metal foil having a carrier and is a metal foil that can be peeled off by the carrier.

The release layer is an inorganic compound or organic compound layer such as a metal, and a known layer can be used as long as it can be peeled off even when subjected to heat treatment at 100 to 300 ° C. during lamination. As the metal oxide, for example, zinc, chromium, nickel, copper, molybdenum, an alloy system, or a mixture of a metal and a metal compound is used. As an organic compound, it is preferable to use what consists of 1 type, or 2 or more types selected from a nitrogen-containing organic compound, a sulfur-containing organic compound, and carboxylic acid.

The nitrogen-containing organic compound is preferably a nitrogen-containing organic compound having a substituent. Specifically, 1,2,3-benzotriazole (hereinafter referred to as “BTA”) which is a triazole compound having a substituent, carboxybenzotriazole (hereinafter referred to as “CBTA”), N ′, N '-Bis (benzotriazolylmethyl) urea (hereinafter referred to as “BTD-U”), 1H-1,2,4-triazole (hereinafter referred to as “TA”) and 3-amino-1H— 1,2,4-triazole (hereinafter referred to as “ATA”) or the like is preferably used.

Examples of the sulfur-containing organic compound include mercaptobenzothiazole (hereinafter referred to as “MBT”), thiocyanuric acid (hereinafter referred to as “TCA”), 2-benzimidazolethiol (hereinafter referred to as “BIT”), and the like. It is preferable to use it.

As the carboxylic acid, it is particularly preferable to use a monocarboxylic acid, and it is particularly preferable to use oleic acid, linoleic acid, linolenic acid, or the like.

As described above, a desired orientation is realized on the upper surface 20 of the copper foil layer 104 of the present embodiment by appropriately controlling the manufacturing method such as increasing the electrolytic density or reducing the film thickness. can do.

Further, at least the lower surface 22 (the surface in contact with one surface of the insulating layer 102) of the copper foil layer 104 used in this embodiment is used to make the adhesion between the copper foil layer 104 and the insulating layer 102 at a practical level or higher. The surface treatment may be performed. Examples of the roughening treatment for the metal foil used for the copper foil layer 104 include rust prevention treatment, chromate treatment, silane coupling treatment, or a combination thereof. Any surface treatment means can be appropriately selected in accordance with the resin material constituting the insulating layer 102.

The rust prevention treatment is performed by forming a thin film on a metal foil by sputtering, electroplating, or electroless plating, for example, any one of metals such as nickel, tin, zinc, chromium, molybdenum, and cobalt, or an alloy thereof. Can be applied. From the viewpoint of cost, electroplating is preferable. In order to facilitate the precipitation of metal ions, a complexing agent such as citrate, tartrate or sulfamic acid can be added in the required amount. The plating solution is usually used in an acidic region and is performed at a temperature of room temperature (for example, 25 ° C.) to 80 ° C. The plating conditions are appropriately selected from the range of current density of 0.1 to 10 A / dm ² , energization time of 1 to 60 seconds, preferably 1 to 30 seconds. The amount of the rust-proofing metal varies depending on the type of metal, but is preferably 10 to 2000 μg / dm ^{2 in} total. If the rust preventive treatment is too thick, it may cause etching inhibition and deterioration of electrical characteristics, and if it is too thin, it may cause a reduction in peel strength with the resin.

Moreover, when the cyanate resin is contained in the resin composition constituting the insulating layer 102, it is preferable that the rust prevention treatment is performed with a metal containing nickel. This combination is useful in that there is little reduction in peel strength in the heat resistance deterioration test and moisture resistance deterioration test.

As the chromate treatment, an aqueous solution containing hexavalent chromium ions is preferably used. The chromate treatment can be performed by a simple immersion treatment, but is preferably performed by a cathode treatment. Sodium dichromate is preferably used under the conditions of 0.1 to 50 g / L, pH 1 to 13, bath temperature 0 to 60 ° C., current density 0.1 to 5 A / dm ² , and electrolysis time 0.1 to 100 seconds. It can also carry out using chromic acid or potassium dichromate instead of sodium dichromate. Further, the chromate treatment is preferably performed on the rust preventive treatment. Thereby, the adhesiveness of an insulating resin composition layer (insulating layer 102) and metal foil (copper foil layer 104) can be improved more.

Examples of the silane coupling agent used in the silane coupling treatment include epoxy functional silanes such as 3-glycidoxypropyltrimethoxysilane and 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-amino Amino-functional silanes such as propyltrimethoxysilane, N-2- (aminoethyl) 3-aminopropyltrimethoxysilane, N-2- (aminoethyl) 3-aminopropylmethyldimethoxysilane, vinyltrimethoxysilane, vinylphenyl Olefin functional silanes such as trimethoxysilane and vinyltris (2-methoxyethoxy) silane, acrylic functional silanes such as 3-acryloxypropyltrimethoxysilane, and methacrylic functional silanes such as 3-methacryloxypropyltrimethoxysilane, 3 - And mercapto-functional silanes such as Le mercaptopropyl trimethoxysilane is used. These may be used alone or in combination. These coupling agents are used by dissolving in a solvent such as water at a concentration of 0.1 to 15 g / L, and applying the obtained solution to a metal foil at a temperature of room temperature to 50 ° C. Adsorb the silane coupling agent on the foil. A coating film is formed on the metal foil by these silane coupling agents being condensed and bonded to the hydroxyl group of the rust-preventing metal on the surface of the metal foil. After the silane coupling treatment, such bonding is stabilized by heating, ultraviolet irradiation or the like. In the heat treatment, for example, drying at a temperature of 100 to 200 ° C. for 2 to 60 seconds is preferable. The ultraviolet irradiation is preferably performed in a wavelength range of 200 to 400 nm and 200 to 2500 mJ / cm ² , for example. The silane coupling treatment is preferably performed on the outermost layer of the metal foil. When the insulating resin composition constituting the insulating layer 102 contains a cyanate resin, it is preferably treated with an aminosilane-based coupling agent. This combination is useful with little reduction in peel strength in heat and moisture resistance tests.

Further, the silane coupling agent used for the silane coupling treatment preferably reacts with the insulating resin composition constituting the insulating layer 102 by heating at 60 to 200 ° C., more preferably 80 to 150 ° C. It is preferable. According to this, the functional group in the said insulating resin composition and the functional group of a silane coupling agent react chemically, and it becomes possible to obtain the more excellent adhesiveness. For example, it is preferable to use a silane coupling agent containing an amino-functional silane for an insulating resin composition containing an epoxy group. This is because the epoxy group and amino group easily form a strong chemical bond by heat, and this bond is extremely stable against heat and moisture. As a combination for forming a chemical bond in this way, epoxy group-amino group, epoxy group-epoxy group, epoxy group-mercapto group, epoxy group-hydroxyl group, epoxy group-carboxyl group, epoxy group-cyanato group, amino group-hydroxyl group And amino group-carboxyl group, amino group-cyanato group and the like.

In addition, it is preferable to use an epoxy resin that is liquid at room temperature as the insulating resin of the insulating resin composition used in this embodiment, and in this case, the viscosity at the time of melting is greatly reduced, so that the wettability at the adhesion interface is improved In addition, a chemical reaction between the epoxy resin and the silane coupling agent is likely to occur, and as a result, a strong peel strength can be obtained. Specifically, bisphenol A type epoxy resin, bisphenol F type epoxy resin, and phenol novolac type epoxy resin having an epoxy equivalent of about 200 are preferable.

Further, when the insulating resin composition contains a curing agent, it is particularly preferable to use a thermosetting latent curing agent as the curing agent. That is, when the functional group in the insulating resin composition and the functional group of the silane coupling agent chemically react, the reaction temperature of the functional group in the insulating resin composition and the functional group of the silane coupling agent is the same as that of the insulating resin composition. It is preferable to select the curing agent so that it is lower than the temperature at which the curing reaction is initiated. Thereby, the reaction between the functional group in the insulating resin composition and the functional group of the silane coupling agent is preferentially and selectively performed, and the metal foil (copper foil layer 104) and the insulating resin composition layer (insulating layer 102) The adhesion of becomes higher. Examples of the thermosetting latent curing agent for the insulating resin composition containing an epoxy resin include solid dispersion-heat-dissolving curing agents such as dicyandiamide, dihydrazide compounds, imidazole compounds, and amine-epoxy adducts, urea compounds, onium salts, Examples thereof include reactive group block type curing agents such as boron trichloride / amine salts and block carboxylic acid compounds.

The prepreg containing the insulating resin composition as described above and the ultrathin copper foil with carrier foil that has been subjected to the roughening treatment with a fine and uniform roughened surface and the above-mentioned surface treatment are laminated and integrated by the above-described method. By making it, the copper clad laminated board 10 with carrier foil as shown to Fig.7 (a) can be obtained. Subsequently, as shown in FIG. 7 (b), the carrier-clad laminate 106 having the copper foil layer 104 on both surfaces of the insulating layer 102 is obtained by peeling off the carrier foil layer 106. At this time, the upper limit value of Ra of the surface of the carrier foil layer 106 facing the surface of the copper foil (that is, the surface in contact with the copper foil) is preferably 1.0 μm or less, and is 0.4 μm or less. Is more preferable and 0.2 μm or less is particularly preferable. The lower limit of Ra is not particularly limited, but is preferably 0.05 or more. On the other hand, the upper limit value of Rz on the surface is preferably 4.0 μm or less, more preferably 2.0 μm or less, and particularly preferably 1.0 μm or less. The lower limit value of Rz is not particularly limited, but is preferably 0.1 μm or more. Note that the present invention is not limited thereto, and the copper foil layer 104 may be formed on at least one surface of the insulating layer 102 or may be formed on the entire surface or a part of the insulating layer 102.

In the present embodiment, the manufacturing method is appropriately controlled such as reducing the roughness of the surface of the carrier foil and / or making the bulk copper crystal grains small and uniform and / or making the bumps small and uniform. Thus, Rp and Rku on one surface 30 of the insulating layer 102 of the present embodiment can be within the above range.

Next, as shown in FIG. 7C, a through hole 108 for interlayer connection is formed in the copper clad laminate 100. Various known means can be used as a method of forming the through hole 108. For example, when forming the through hole 108 having a hole diameter of 100 μm or more, means using a drill or the like is used from the viewpoint of productivity. In order to form the through-hole 108 of 100 μm or less, means using a gas laser such as carbon dioxide or excimer, or a solid laser such as YAG is suitable.

Next, at least a catalyst nucleus can be provided on the copper foil layer 104, but in this embodiment, the catalyst nucleus is provided on the entire surface of the copper foil layer 104 and on the inner wall surface of the through hole 108. The catalyst nucleus is not particularly limited. For example, a noble metal ion or palladium colloid can be used. Subsequently, an electroless plating layer is formed using this catalyst nucleus as a nucleus. Before the electroless plating treatment, for example, smear removal with a chemical solution or the like may be performed on the surface of the copper foil layer 104 or the through hole 108. good. The desmear treatment is not particularly limited, and is a wet method using an oxidant solution having an organic substance decomposing action, and an organic substance by irradiating a target object with an active species (plasma, radical, etc.) having a strong oxidizing action directly. A known method such as a dry method such as a plasma method for removing the residue can be used. Specific examples of the wet desmear treatment include a method in which the resin surface is subjected to a swelling treatment, etched by an alkali treatment, and then subjected to a neutralization treatment.

Next, as shown in FIG. 7 (d), a thin electroless plating layer 110 is formed on the copper foil layer 104 provided with catalyst nuclei and the inner walls of the through holes 108 by electroless plating. The electroless plating layer 110 electrically connects the copper foil layer 104 on the upper surface of the insulating layer 102 and the copper foil layer 104 on the lower surface thereof. 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 stabilize the plating film by performing a heat treatment at 100 to 250 ° C. after the electroless plating. A heat treatment at 120 to 180 ° C. is particularly preferable in that a film capable of suppressing oxidation can be formed. Further, the average thickness of the electroless plating layer 110 may be any thickness that allows the next electroplating to be performed. For example, about 0.1 to 1 μm is sufficient. Further, the inside of the through hole 108 may be filled with a conductive paste or an insulating paste, or may be filled with electric pattern plating.

Next, as shown in FIG. 7E, a resist layer 112 having a predetermined opening pattern is formed on the electroless plating layer 110 provided on the copper foil layer 104. This opening pattern corresponds to a conductive circuit pattern described later. Therefore, the resist layer 112 is provided so as to cover the non-circuit formation region on the copper foil layer 104. In other words, the resist layer 112 is not formed in the conductive circuit formation region on the through hole 108 and the copper foil layer 104. The resist layer 112 is not particularly limited, and a known material 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 resist layer 112. In order to form the resist layer 112, for example, a photosensitive dry film is laminated on the electroless plating layer 110, the non-circuit formation region is exposed and photocured, and the unexposed portion is dissolved and removed with a developer. The remaining cured photosensitive dry film becomes the resist layer 112. It is preferable that the thickness of the resist layer 112 be equal to or greater than the thickness of the conductor (plating layer 114) to be subsequently plated.

Next, as shown in FIG. 8A, a plating layer 114 is formed by electroplating at least inside the opening pattern of the resist layer 112 and on the electroless plating layer 110. At this time, the copper foil layer 104 serves as a power feeding layer. In the present embodiment, the plating layer 114 may be provided continuously over the upper surface of the insulating layer 102, the inner wall of the through hole 108, and the lower surface thereof. Such electroplating is not particularly limited, but a known method used in ordinary printed wiring boards can be used. For example, in a state where the plating solution is immersed in a plating solution such as copper sulfate, an electric current is supplied to the plating solution. A method such as flowing a stream can be used. The thickness of the plating layer 114 is not particularly limited as long as it can be used as a circuit conductor. For example, the thickness is preferably in the range of 1 to 100 μm, and more preferably in the range of 5 to 50 μm. The plating layer 114 may be a single layer or may have a multilayer structure. The material of the plating layer 114 is not particularly limited, and for example, copper, copper alloy, 42 alloy, nickel, iron, chromium, tungsten, gold, solder, and the like can be used.

Next, as shown in FIG. 8B, the resist layer 112 is removed using an alkaline stripping solution, sulfuric acid, a commercially available resist stripping solution, or the like.

Next, as shown in FIG. 8C, the electroless plating layer 110 and the copper foil layer 104 other than the region where the plating layer 114 is formed are removed. As a technique for removing the copper foil layer 104, for example, soft etching (flash etching) or the like is used. Thereby, the pattern of the conductive circuit 118 comprised by laminating | stacking the copper foil layer 104 and the metal layer 116 (the electroless-plating layer 110 and the plating layer 114) can be formed.

As the cross-sectional shape of the conductive circuit 118 of the printed wiring board 200 of the second embodiment, as shown in FIG. 9, in addition to the normal rectangular shape, the reverse tapered shape shown in FIG. Either the kamaboko shape shown in (b) or the constricted shape shown in FIG.

Here, the etching solution used for the soft etching of this embodiment will be described below. The etching solution is not particularly limited. However, when a conventional diffusion-controlled etching solution is used, circuit formation tends to be deteriorated because the exchange of the solution is inevitably worsened for fine portions of the wiring. For this reason, it is desirable to use an etching solution in which the reaction between copper and the etching solution proceeds not at a diffusion rate but at a reaction rate. If the reaction between copper and the etchant is reaction-controlled, the etching rate does not change even if diffusion is further increased. That is, there is no difference in etching rate between a place where the liquid exchange is good and a place where the liquid exchange is bad. As such a reaction-limited etching solution, for example, one containing hydrogen peroxide and an acid not containing a halogen element as main components can be mentioned. Since hydrogen peroxide is used as the oxidizing agent, strict etching rate control becomes possible by managing the concentration. If a halogen element is mixed in the etching solution, the dissolution reaction tends to be diffusion-limited. As the acid not containing halogen, nitric acid, sulfuric acid, organic acid, and the like can be used, but sulfuric acid is preferable because it is inexpensive. Further, when sulfuric acid and hydrogen peroxide are the main components, the respective concentrations are preferably 5 to 300 g / L and 5 to 200 g / L from the viewpoint of etching rate and liquid stability. Examples thereof include ammonium persulfate, sodium persulfate, and sodium persulfate.

Thus, the conductive circuit 118 having a desired shape can be obtained by appropriately selecting the etching characteristics and etching conditions of the copper foil layer 104. As described above, the printed wiring board 200 in which the conductive circuit 118 is formed on both surfaces of the insulating layer 102 is obtained. In addition, in the method for manufacturing the printed wiring board 200 of the second embodiment, the same effects as those of the first embodiment can be obtained.

As shown in FIG. 8D-1, a solder resist layer 120 may be formed so as to cover the insulating layer 102 and part of the conductive circuit 118. As the solder resist layer 120, for example, a filler or a substrate excellent in insulating properties may be included, and a heat resistant resin composition such as a photosensitive resin, a thermosetting resin, and a thermoplastic resin is used. Next, the first plating layer 122 and the second plating layer 124 may be further formed on the conductive circuit 118 provided with the opening of the solder resist layer 120. Thereby, the metal layer 116 may have a multilayer structure of two or more. As the first plating layer 122 and the second plating layer 124, a gold plating layer can be adopted. The gold plating method may be a conventionally known method, and is not particularly limited. For example, electroless nickel plating is performed on the plating layer 114 to about 0.1 to 10 μm, and displacement gold plating is performed to 0.01 to 0. There is a method of performing electroless gold plating about 0.1 to 2 μm after about 5 μm. As a result, the printed wiring board 202 shown in FIG. 8D-1 is obtained.
Further, as shown in FIG. 8D-2, the first plating layer 122 and the second plating layer 124 may be formed around the conductive circuit 118 without forming the solder resist layer 120. . As these 1st plating layer 122 and 2nd plating layer 124, you may employ | adopt the laminated body of a nickel plating layer and a gold plating layer, for example. Thus, the printed wiring board 204 shown in FIG. 8D-2 is obtained.

Also, a semiconductor device (not shown) can be mounted on these printed

wiring boards

200, 202, and 204 to obtain a semiconductor device.

(Third embodiment)
Next, the manufacturing method of the printed wiring board of 3rd Embodiment is demonstrated.
10 to 12 are cross-sectional views showing the steps of the manufacturing process of the printed wiring board manufacturing method according to the third embodiment. The printed wiring board manufacturing method of the third embodiment uses, for example, the printed

wiring boards

200, 202, and 204 obtained in the second embodiment as inner layer circuit boards, and builds on the inner layer circuit boards. An up layer is further formed.

First, the printed wiring board 200 obtained in FIG. 8C is adopted as the inner layer circuit board. The inner layer circuit (conductive circuit 118) of the printed wiring board 200 is subjected to a roughening process. Here, the roughening treatment means performing a chemical treatment, a plasma treatment, or the like on the surface of the conductor circuit. As the roughening treatment, for example, a blackening treatment using oxidation reduction or a chemical solution treatment using a known roughening solution of sulfuric acid-hydrogen peroxide system can be used. Thereby, the adhesiveness of the interlayer insulation material which comprises the insulating layer 130, and the conductive circuit 118 of the printed wiring board 200 can be improved. In addition, the inner layer circuit board is not particularly limited in place of the printed wiring board 200 obtained in the second embodiment, but the resin composition does not include a prepreg or a base material by a plated through hole method, a build-up method, or the like. A normal multilayer printed wiring board in which physical layers and the like are laminated can also be used. The conductor circuit layer serving as the inner layer circuit may be formed by a conventionally known circuit forming method. In multilayer printed wiring boards, through-holes are formed by drilling, laser processing, etc. on the laminate (a laminate obtained by laminating multiple prepregs) and metal-clad laminate as the core layer. Then, the inner circuit on both sides can be electrically connected by plating or the like.

Next, as shown in FIG. 10 (a), an insulating layer 130 (prepreg) and a copper foil layer 105 with a carrier foil layer 107 (carrier foil) are formed on both sides of a printed wiring board 200 having a roughened conductor circuit surface, respectively. With ultra-thin copper foil). Next, as shown in FIG. 10 (b), a multilayer laminate is formed by subjecting the laminate in which these layers are stacked to heat and pressure. Subsequently, as shown in FIG. 10C, the carrier foil layer 107 is peeled and removed.

Next, as shown in FIG. 10D, a part of the insulating layer 130 and the copper foil layer 105 is removed to form a hole 109. A part of the surface of the conductive circuit 118 is exposed on the bottom surface of the hole 109. The method for forming the hole 109 is not particularly limited. For example, a method of forming a blind via hole having a hole diameter of 100 μm or less using a gas laser such as carbon dioxide gas or excimer or a solid laser such as YAG is used. it can. In addition, although the hole 109 is represented by a non-through hole in FIG. 10D, it may be a through hole. In the case of a through hole, it may be formed by laser irradiation or using a drilling machine.

Next, as shown in FIG. 11A, a thin electroless plating layer 111 is formed on the conductive circuit 118 provided with the above-described catalyst nucleus, on the inner wall of the hole 109, and on the copper foil layer 105. The electroless plating layer 111 is formed in the same manner as the electroless plating layer 110 described above. Before this electroless plating, as described above, desmear treatment such as smear removal with a chemical solution may be performed. Further, the thickness of the electroless plating layer 110 may be any thickness that allows subsequent electroplating to be performed, and about 0.1 to 1 μm is sufficient. Further, the inside of the hole 109 (blind via hole) can be filled with a conductive paste or an insulating paste, or may be filled with electric pattern plating.

Next, as shown in FIG. 11B, a resist layer 113 having an opening pattern corresponding to the conductor circuit pattern is formed on the electroless plating layer 110. In other words, the non-circuit forming portion is masked by forming the resist layer 113. As this resist layer 113, the thing similar to the above-mentioned resist layer 112 can be used. The thickness of the resist layer 113 is preferably set to be approximately the same as or thicker than that of the conductor circuit to be subsequently plated.

Next, as shown in FIG. 11C, a plating layer 132 is formed inside the opening pattern of the resist layer 113. The plating layer 132 may be formed on the conductive circuit 118 inside the hole 109 or may be formed on the electroless plating layer 111 inside the opening pattern. The electroplating for forming the plating layer 132 can use the same technique as that for the plating layer 114 described above. The thickness of the plating layer 132 may be used as a circuit conductor. For example, the thickness is preferably in the range of 1 to 100 μm, and more preferably in the range of 5 to 50 μm.

Next, as shown in FIG. 12A, the resist layer 113 is peeled in the same manner as the resist layer 112 described above. Next, as shown in FIG. 12B, the copper foil layer 105 and the electroless plating layer 111 are removed by soft etching (flash etching) in the same manner as the copper foil layer 104 described above. Thereby, the conductive circuit pattern comprised from the copper foil layer 105, the electroless-plating layer 111, and the plating layer 132 can be formed. In addition, vias and pads that are electrically connected to the conductive circuit 118 can be formed using the plating layer 132. The printed wiring board 201 is obtained as described above.

As shown in FIG. 12 (c-1), a solder resist layer 121 may be formed on the insulating layer 130, the conductive circuit pattern plating layer 132, and a part of the pad plating layer 132. As the solder resist layer 121, the same thing as the above-mentioned solder resist layer 120 can be used. Next, a first plating layer 123 and a second plating layer 125 made of, for example, a nickel plating layer and a gold plating layer are further formed on the plating layer 132 in which the opening of the solder resist layer 121 is provided. May be. Thus, the printed wiring board 203 shown in FIG. 12C-1 is obtained.
Further, as shown in FIG. 12C-2, the first plating layer 123 and the second plating layer 125 described above are formed around the conductive circuit pattern and the pad without forming the solder resist layer 121. May be formed. As a result, the printed wiring board 205 shown in FIG. 12C-2 is obtained. In the third embodiment, the same effect as in the first and second embodiments can be obtained.

A modification of the method for manufacturing a printed wiring board according to the present embodiment will be described with reference to FIG.
In the first to third embodiments described above, the metal layer is selectively formed on the copper foil, but the present modification is different in that the metal layer is formed on the entire surface of the copper foil. It is.
Hereinafter, a method for manufacturing the printed wiring board of the present modification will be described.
First, as shown to Fig.13 (a), the copper clad laminated board 10 with carrier foil is prepared. In this copper clad laminate 10 with carrier foil, a carrier foil layer 106 is attached to both surfaces of the insulating layer 102 together with the copper foil layer 104. Then, as shown in FIG.13 (b), the carrier foil layer 106 is peeled from the copper clad laminated board 10 with carrier foil. Subsequently, as shown in FIG. 13C, a metal layer 115 (plating layer) is formed on the entire surface of the copper foil layer 104 by plating. Subsequently, as shown in FIG. 13D, a resist layer 112 having a predetermined opening pattern is formed on the plane-shaped metal layer 115. Subsequently, as shown in FIG. 13E, the metal layer 115 and the copper foil layer 104 in the opening pattern of the resist layer 112 are removed by, for example, etching. Thereafter, as shown in FIG. 13F, the resist layer 112 is removed. Thereby, the pattern of the conductive circuit 119 comprised from the copper foil layer 104 and the metal layer 115 can be formed. The printed wiring board 101 of this modification is obtained by the above process.

As described above, according to the present embodiment, a fine circuit processing of an ultrathin copper foil with a carrier foil, a fine circuit shape, a method of manufacturing a printed wiring board excellent in insulation reliability, and the printed wiring board It becomes possible to provide.

The printed wiring board manufacturing method of the present embodiment is not only for forming a conductor circuit layer on both sides of a printed wiring board substrate, but also for forming a conductor circuit layer only on one side of the printed wiring board substrate. Can be applied. Further, the double-sided printed wiring board as shown in FIG. 8C can be applied to the multilayer printed wiring board of the third embodiment using the inner layer circuit board. Therefore, any of a single-sided printed wiring board, a double-sided printed wiring board, and a multilayer printed wiring board can be produced by the method for producing a printed wiring board of the present embodiment.

Hereinafter, an electrolytic copper foil with a carrier foil according to the present invention and a copper-clad laminate using the copper foil will be manufactured, and an embodiment of a method for manufacturing a printed wiring board according to the present invention will be described. Here, the case where an electrolytic copper foil is used as the carrier foil will be mainly described. The present invention will be described in detail based on examples and comparative examples, but the present invention is not limited thereto.

(Manufacture of metal foil 1)
18 μm thick electrolytic copper foil (made by Mitsui Kinzoku Kogyo Co., Ltd., 3EC-VLP, glossy surface roughness Ra = 0.2 μm, Rz = 1.5 μm) on the carrier foil, the bonding interface layer and ultrathin Copper foil layers were sequentially formed. As manufacturing conditions, first, the carrier foil was immersed in an acid cleaning tank (dilute sulfuric acid solution, 150 g / L, liquid temperature 30 ° C.) for 20 seconds to remove oil and oxide film on the surface. Next, it was immersed in a bonding interface forming tank (carboxybenzotriazole solution, 5 g / L, liquid temperature 40 ° C., pH 5) to form a bonding interface layer on the glossy surface of the carrier foil. Next, while dipping in a bulk copper formation tank (copper sulfate solution; sulfuric acid concentration 150 g / L, copper concentration 65 g / L, gelatin concentration 10 ppm, chloride ion 20 ppm, liquid temperature 45 ° C.) A flat anode electrode (lead) was placed in parallel and electrolyzed under smooth plating conditions with a current density of 15 A / dm ² to form a 1.5 μm bulk copper layer. Next, while immersing in the surface of the bulk copper layer in a fine copper grain formation tank (copper sulfate solution; sulfuric acid concentration 100 g / L, sulfuric acid solution with copper concentration 18 g / L, liquid temperature 25 ° C.) A flat anode electrode (lead) was arranged in parallel, and electrolysis was performed under the condition of burnt plating with a current density of 10 A / dm ² . Then, the plating tank cover to prevent falling off of the fine copper particles (copper sulfate solution; sulfuric acid concentration 150 g / L, copper concentration 65 g / L, liquid temperature 45 ° C.) while immersed in, the current density 20A / dm ² Electrolysis was performed under smooth plating conditions to form 0.5 μm fine roughening, and an ultrathin copper foil having a total thickness of 2.0 μm was produced. Next, it is immersed in a rust prevention treatment tank (zinc sulfate solution; sulfuric acid concentration 70 g / L, zinc concentration 20 g / L, liquid temperature 40 ° C.), electrolyzed at a current density of 15 A / dm ² and subjected to rust prevention treatment using zinc. went. Here, a soluble anode using a zinc plate as the anode electrode was used. Next, it was immersed in a chromate treatment tank (chromic acid solution; chromic acid concentration 5 g / L, pH 11.5, liquid temperature 55 ° C.) for 4 seconds. Finally, a copper foil with a carrier foil was obtained by passing through a furnace heated to an atmospheric temperature of 110 ° C. by an electric heater in a drying treatment tank over 60 seconds. In addition, it is immersed and washed in the water washing tank which can be washed for about 30 seconds between the processes for each tank.

(Manufacture of metal foil 2)
The carrier foil has a 12 μm thick electrolytic copper foil (F2-WS, manufactured by Furukawa Electric Co., Ltd., glossy surface roughness Ra = 0.2 μm, Rz = 1.2 μm) on the glossy surface and the bonding interface layer and ultrathin Copper foil layers were sequentially formed. As manufacturing conditions, first, the carrier foil was immersed in an acid cleaning tank (dilute sulfuric acid solution, 150 g / L, liquid temperature 30 ° C.) for 20 seconds to remove oil and oxide film on the surface. Next, it was immersed in a bonding interface forming tank (carboxybenzotriazole solution, 5 g / L, liquid temperature 40 ° C., pH 5) to form a bonding interface layer on the glossy surface of the carrier foil. Next, while dipping in a bulk copper formation tank (copper sulfate solution; sulfuric acid concentration 150 g / L, copper concentration 65 g / L, gelatin concentration 10 ppm, chloride ion 20 ppm, liquid temperature 45 ° C.) A flat anode electrode (lead) was placed in parallel and electrolyzed under smooth plating conditions with a current density of 20 A / dm ² to form a bulk copper layer of 1.5 μm. Next, while immersing in the surface of the bulk copper layer in a fine copper grain formation tank (copper sulfate solution; sulfuric acid concentration 100 g / L, sulfuric acid solution with copper concentration 18 g / L, liquid temperature 25 ° C.) A flat anode electrode (lead) was arranged in parallel, and electrolysis was performed under the condition of burnt plating with a current density of 10 A / dm ² . Next, a current density of 20 A / dm ^{2 is} applied while being immersed in a coating bath (copper sulfate solution; sulfuric acid concentration 150 g / L, copper concentration 65 g / L, liquid temperature 45 ° C.) for preventing fine copper particles from falling off. Electrolysis was performed under smooth plating conditions to form 0.5 μm fine roughening, and an ultrathin copper foil having a total thickness of 2.0 μm was produced. Then, antirust treatment tank (zinc sulfate solution; sulfuric acid concentration of 70 g / L, zinc concentration 20 g / L, liquid temperature 40 ° C.) was immersed in the rust-proof treatment with zinc and electrolysis at a current density of 15A / dm ² went. Here, a soluble anode using a zinc plate as the anode electrode was used. Next, it was immersed in a chromate treatment tank (chromic acid solution; chromic acid concentration 5 g / L, pH 11.5, liquid temperature 55 ° C.) for 4 seconds. Finally, a copper foil with a carrier foil was obtained by passing through a furnace heated to an atmospheric temperature of 110 ° C. by an electric heater in a drying treatment tank over 60 seconds. In addition, it is immersed and washed in the water washing tank which can be washed for about 30 seconds between the processes for each tank.

(Manufacture of metal foil 3)
The carrier foil has a 12 μm thick electrolytic copper foil (F2-WS, manufactured by Furukawa Electric Co., Ltd., glossy surface roughness Ra = 0.2 μm, Rz = 1.2 μm) on the glossy surface and the bonding interface layer and ultrathin Copper foil layers were sequentially formed. As manufacturing conditions, first, the carrier foil was immersed in an acid cleaning tank (dilute sulfuric acid solution; 150 g / L, liquid temperature 30 ° C.) for 20 seconds to remove oil and oxide film on the surface. Next, it was immersed in a bonding interface formation tank (carboxybenzotriazole solution; 5 g / L, liquid temperature 40 ° C., pH 5) to form a bonding interface layer on the glossy surface of the carrier foil. Next, bulk copper formation tank 1 (copper pyrophosphate solution; potassium pyrophosphate concentration 320 g / L, copper concentration 80 g / L, gelatin concentration 10 ppm, chloride ion 10 ppm, 25% aqueous ammonia 2 ml / L, pH 8.5, While being immersed in a liquid temperature of 40 ° C., a flat anode electrode (lead) is placed in parallel on one side of the carrier foil, electrolyzed under smooth plating conditions with a current density of 7 A / dm ² , and then a bulk copper forming tank 2 (copper sulfate solution; sulfuric acid concentration: 100 g / L, copper concentration: 200 g / L, gelatin concentration: 10 ppm, chloride ion: 20 ppm, liquid temperature: 45 ° C.) ) In parallel and electrolyzed under smooth plating conditions with a current density of 10 A / dm ² to form a bulk copper layer of 1.5 μm. Next, while immersing in the surface of the bulk copper layer in a fine copper grain formation tank (copper sulfate solution; sulfuric acid concentration 100 g / L, sulfuric acid solution with copper concentration 18 g / L, liquid temperature 25 ° C.) A flat anode electrode (lead) was arranged in parallel, and electrolysis was performed under the condition of burnt plating with a current density of 10 A / dm ² . Next, a current density of 20 A / dm ^{2 is} applied while being immersed in a coating bath (copper sulfate solution; sulfuric acid concentration 150 g / L, copper concentration 65 g / L, liquid temperature 45 ° C.) for preventing fine copper particles from falling off. Electrolysis was performed under smooth plating conditions to form 0.5 μm fine roughening, and an ultrathin copper foil having a total thickness of 2.0 μm was produced. Next, it is immersed in a rust prevention treatment tank (zinc sulfate solution; sulfuric acid concentration 70 g / L, zinc concentration 20 g / L, liquid temperature 40 ° C.), electrolyzed at a current density of 15 A / dm ² and subjected to rust prevention treatment using zinc. went. Here, a soluble anode using a zinc plate as the anode electrode was used. Next, it was immersed in a chromate treatment tank (chromic acid solution; chromic acid concentration 5 g / L, pH 11.5, liquid temperature 55 ° C.) for 4 seconds. Finally, a copper foil with a carrier foil was obtained by passing through a furnace heated to an atmospheric temperature of 110 ° C. by an electric heater in a drying treatment tank over 60 seconds. In addition, it is immersed and washed in the water washing tank which can be washed for about 30 seconds between the processes for each tank.

Example 1
As epoxy resin, 8.5 parts by weight of naphthalene-modified cresol novolak epoxy resin (manufactured by DIC, HP-5000), and as phenol curing agent, biphenylaralkyl type phenol resin (Maywa Kasei Co., Ltd., MEH7851-4H) 8.5 parts by weight. , 17 parts by weight of a phenol novolac type cyanate resin (manufactured by LONZA, Primaset PT-30), 65.5 parts by weight of spherical fused silica (manufactured by Admatechs, SO-25R, average particle size 0.5 μm), epoxy silane (Shin-Etsu) 0.5 parts by weight of KBM-403) manufactured by Chemical Industry Co., Ltd. was mixed and dissolved in methyl ethyl ketone. Subsequently, it stirred using the high-speed stirring apparatus and adjusted so that it might become 70 weight% of non volatile matters, and the resin varnish was prepared.
The resin varnish was impregnated into a glass woven fabric (basis weight 104 g, thickness 87 μm, N glass fiber woven fabric manufactured by Nittobo Co., Ltd., WEA-116E), dried in a heating furnace at 150 ° C. for 2 minutes, and varnish solid in the prepreg A prepreg of about 50% by weight was obtained.
Two prepregs are stacked, and an ultra-thin copper foil (metal foil 1) with a carrier foil is stacked and heated and pressure-molded at a pressure of 3 MPa and a temperature of 220 ° C. for 2 hours. A laminated board having was obtained.

(Printed wiring board)
The carrier foil of the laminate obtained in the example was peeled and removed (FIG. 7 (b)), and as shown in FIG. 7 (c), a carbon dioxide laser (ML605GTX3 manufactured by Mitsubishi Electric Corporation) was applied from above the ultrathin metal foil. A through-hole having a diameter of 75 μm was opened by −5100 U2), and immersed in an aqueous solution of potassium permanganate 60 g / L and sodium hydroxide 45 g / L at a liquid temperature of 80 ° C. for 2 minutes to perform desmear treatment.
Thereafter, it was immersed in a palladium solution (MAT-2B / MAT-2A, manufactured by Uemura Kogyo Co., Ltd.) for 5 minutes at a liquid temperature of 55 ° C. to give a catalyst. Was immersed for 15 minutes to form an electroless plating layer of 0.7 μm (FIG. 7D).
On the surface of this electroless plating layer, a 25 μm-thick UV photosensitive dry film (Sunfort UFG-255, manufactured by Asahi Kasei Co., Ltd.) was bonded using a hot roll laminator, and a pattern with a minimum line width / line spacing of 20/20 μm was formed. Using a drawn glass mask (manufactured by Topic Co., Ltd.), the position is adjusted, exposure is performed with an exposure apparatus (Ono Sokki EV-0800), and development is performed with a sodium carbonate aqueous solution to form a resist mask (FIG. 7 ( e)). Next, electrolytic copper plating (81-HL manufactured by Okuno Pharmaceutical Co., Ltd.) was performed at 3 A / dm ² for 25 minutes using the electroless plating layer as a power feeding layer electrode to form a copper wiring pattern having a thickness of about 20 μm (see FIG. 8 (a)). Next, the resist mask was peeled off with a monoethanolamine solution (R-100, manufactured by Mitsubishi Gas Chemical Company) using a peeling machine (FIG. 8B). Then, the electroless plating layer and the underlying copper foil (2 μm) as the power feeding layer are removed by treating for 180 seconds with flash etching (CPE-800 manufactured by Mitsubishi Gas Chemical Company, liquid temperature: 30 ° C., spray pressure: 0.23 MPa). Then, a pattern of L / S = 20/20 μm was formed (patterned etching) to obtain a printed wiring board (FIG. 8C).
Finally, as shown in FIG. 8 (d-1), a solder resist (manufactured by Taiyo Ink, PSR4000 / AUS308) is formed on the circuit surface, and a nickel plating layer (Okuno Pharmaceutical Co., Ltd., ICP Nicolon GM) is formed. Immerse it for 12 minutes at a liquid temperature of 80 ° C. for 2.5 μm, then immerse the gold plating layer (Okuno Pharmaceutical Co., Ltd., Flash Gold 330) for 9 minutes at a liquid temperature of 80 ° C. to form 0.05 μm. Obtained. As shown in FIG. 8D-2, there is a case where no solder resist is formed on the circuit surface.

(Example 2)
Example 1 was the same as Example 1 except that the ultrathin copper foil with carrier foil was changed to metal foil 2.

(Example 3)
Example 1 was the same as Example 1 except that the ultrathin copper foil with carrier foil was changed to metal foil 3.

Example 4
Example 1 was the same as Example 1 except that the conditions for flash etching of the electroless plating layer as the power feeding layer and the underlying copper foil (2 μm) were changed as follows.
The electroless plating layer and the underlying copper foil (2 μm) as the power feeding layer were removed by treating for 240 seconds with flash etching (CPE-800 manufactured by Mitsubishi Gas Chemical Company, liquid temperature: 30 ° C., spray pressure 0.23 MPa). A pattern of L / S = 20/20 μm was formed (patterned etching) to obtain a printed wiring board.

(Example 5)
It was the same as Example 1 except having changed the resin composition used for a laminated board.
As an epoxy resin, 11 parts by weight of a biphenyl aralkyl type epoxy resin (manufactured by Nippon Kayaku Co., Ltd., NC-3000), 20 parts by weight of a bismaleimide compound (manufactured by KAI Kasei Kogyo Co., Ltd., BMI-70), 4,4′-diaminodiphenylmethane 3 0.5 parts by weight, 65 parts by weight of aluminum hydroxide (HP-360, Showa Denko) and 0.5 parts by weight of epoxy silane (KBE-403, manufactured by Shin-Etsu Chemical Co., Ltd.) were mixed and dissolved in methyl ethyl ketone. Subsequently, it stirred using the high-speed stirring apparatus and adjusted so that it might become 70 weight% of non volatile matters, and the resin varnish was prepared.
The resin varnish was impregnated into a glass woven fabric (basis weight 104 g, thickness 87 μm, Nittobo E glass woven fabric, WEA-116E), dried in a heating furnace at 150 ° C. for 2 minutes, and varnish solid content in the prepreg About 50% by weight of prepreg was obtained. Two prepregs are stacked, and an ultra-thin copper foil (metal foil 1) with a carrier foil is stacked and heat-pressed at a pressure of 3 MPa and a temperature of 200 ° C. for 1 hour. A laminated board having was obtained.

(Comparative Example 1)
(Manufacture of metal foil 4)
The carrier foil has a 35 μm-thick electrolytic copper foil (F2-WS, manufactured by Furukawa Electric Co., Ltd., glossy surface roughness Ra = 0.2 μm, Rz = 1.2 μm). Copper foil layers were sequentially formed. As manufacturing conditions, first, the carrier foil was immersed in an acid cleaning tank (dilute sulfuric acid solution, 150 g / L, liquid temperature 30 ° C.) for 20 seconds to remove oil and oxide film on the surface. Next, it was immersed in a bonding interface forming tank (carboxybenzotriazole solution, 5 g / L, liquid temperature 40 ° C., pH 5) to form a bonding interface layer on the glossy surface of the carrier foil. Next, while immersing in a bulk copper formation tank (copper sulfate solution; sulfuric acid concentration 150 g / L, copper concentration 65 g / L, liquid temperature 45 ° C.), a flat plate anode electrode (lead) is applied to one side of the carrier foil. A 1.5-μm bulk copper layer was formed by parallel placement and electrolysis under smooth plating conditions with a current density of 2 A / dm ² . Next, while immersing in the surface of the bulk copper layer in a fine copper grain formation tank (copper sulfate solution; sulfuric acid concentration 100 g / L, sulfuric acid solution with copper concentration 18 g / L, liquid temperature 25 ° C.) the anode electrode of the flat plate (lead) arranged parallel, electrolysis was burnt plating a current density of 5A / dm ^2. Next, a current density of 10 A / dm ^{2 is} applied while being immersed in a covering plating tank (copper sulfate solution; sulfuric acid concentration 150 g / L, copper concentration 65 g / L, liquid temperature 45 ° C.) for preventing fine copper particles from falling off. Electrolysis was performed under smooth plating conditions to form 0.5 μm fine roughening, and an ultrathin copper foil having a total thickness of 2.0 μm was produced. Next, it is immersed in a rust prevention treatment tank (zinc sulfate solution; sulfuric acid concentration 70 g / L, zinc concentration 20 g / L, liquid temperature 40 ° C.), electrolyzed at a current density of 10 A / dm ² and subjected to rust prevention treatment using zinc. went. Here, a soluble anode using a zinc plate as the anode electrode was used. Next, it was immersed in a chromate treatment tank (chromic acid solution; chromic acid concentration 5 g / L, pH 11.5, liquid temperature 55 ° C.) for 4 seconds. Finally, a copper foil with a carrier foil was obtained by passing through a furnace heated to an atmospheric temperature of 110 ° C. by an electric heater in a drying treatment tank over 60 seconds. In addition, it is immersed and washed in the water washing tank which can be washed for about 30 seconds between the processes for each tank.
A printed wiring board was obtained in the same manner as in Example 1 except that the ultrathin copper foil with carrier foil was changed to metal foil 4.

(Comparative Example 2)
(Manufacture of metal foil 5)
The carrier foil has a 35 μm-thick electrolytic copper foil (F2-WS, manufactured by Furukawa Electric Co., Ltd., glossy surface roughness Ra = 0.2 μm, Rz = 1.2 μm). Copper foil layers were sequentially formed. As manufacturing conditions, first, the carrier foil was immersed in an acid cleaning tank (dilute sulfuric acid solution; 150 g / L, liquid temperature 30 ° C.) for 20 seconds to remove oil and oxide film on the surface. Next, it was immersed in a bonding interface formation tank (carboxybenzotriazole solution; 5 g / L, liquid temperature 40 ° C., pH 5) to form a bonding interface layer on the glossy surface of the carrier foil. Next, while immersed in a bulk copper formation tank 1 (copper pyrophosphate solution; potassium pyrophosphate concentration 320 g / L, copper concentration 80 g / L, 25% aqueous ammonia 2 ml / L, pH 8.5, liquid temperature 40 ° C.) A flat anode electrode (lead) is arranged in parallel to one side of the carrier foil, electrolyzed under smooth plating conditions with a current density of 1.5 A / dm ² , and then a bulk copper forming tank 2 (copper sulfate solution; sulfuric acid) A flat plate anode electrode (lead) is placed in parallel to one side of the carrier foil while being immersed in a concentration of 100 g / L, a copper concentration of 200 g / L, and a liquid temperature of 45 ° C., and smooth plating conditions with a current density of 3 A / dm ² Was used to form a 1.5 μm bulk copper layer. Next, while immersing in the surface of the bulk copper layer in a fine copper grain formation tank (copper sulfate solution; sulfuric acid concentration 100 g / L, sulfuric acid solution with copper concentration 18 g / L, liquid temperature 25 ° C.) A flat anode electrode (lead) was arranged in parallel, and electrolysis was performed under the condition of burnt plating with a current density of 5 A / dm ² . Next, a current density of 10 A / dm ^{2 is} applied while being immersed in a covering plating tank (copper sulfate solution; sulfuric acid concentration 150 g / L, copper concentration 65 g / L, liquid temperature 45 ° C.) for preventing fine copper particles from falling off. Electrolysis was performed under smooth plating conditions to form 0.5 μm fine roughening, and an ultrathin copper foil having a total thickness of 2.0 μm was produced. Then, antirust treatment tank (zinc sulfate solution; sulfuric acid concentration of 70 g / L, zinc concentration 20 g / L, liquid temperature 40 ° C.) was immersed in the rust-proof treatment with zinc and electrolysis at a current density of 15A / dm ² went. Here, a soluble anode using a zinc plate as the anode electrode was used. Next, it was immersed in a chromate treatment tank (chromic acid solution; chromic acid concentration 5 g / L, pH 11.5, liquid temperature 55 ° C.) for 4 seconds. Finally, a copper foil with a carrier foil was obtained by passing through a furnace heated to an atmospheric temperature of 110 ° C. by an electric heater in a drying treatment tank over 60 seconds. In addition, it is immersed and washed in the water washing tank which can be washed for about 30 seconds between the processes for each tank.
A printed wiring board was obtained in the same manner as in Example 1 except that the ultrathin copper foil with carrier foil was changed to the metal foil 5.

(Evaluation)
The following evaluation was performed using the printed wiring board obtained in each Example and Comparative Example. The evaluation items are shown together with the contents, and the obtained results are shown in Table 1.

(Evaluation)
The following evaluation was performed using the printed wiring board obtained in each Example and Comparative Example. The evaluation items are shown together with the contents, and the obtained results are shown in Table 1. Further, SEM images of Example 1 and Comparative Example 1 are shown in FIGS. 16 and 17.

(1) Surface roughness of insulating layer (Rp, Rku)
Using a color 3D laser microscope (manufactured by Keyence Corporation, device name VK-9710), the maximum peak height Rp of the roughness curve and the kurtosis (kurtosis) Rku of the roughness curve were measured according to JIS B0601: 2001 (no cut-off value). ). The measurement was performed by setting the observation visual field surface at 100 μm × 100 μm at an arbitrary 20 points (20 places) on the measurement piece, and setting the average value. In addition, the sample obtained by peeling and removing the carrier foil of the obtained laminate (FIG. 7A) and etching the entire surface of the ultrathin copper foil with a copper chloride etchant was used as a sample.

(2) State of insulating layer surface after flash etching and presence / absence of copper residue Using a scanning electron microscope (manufactured by JEOL Ltd., apparatus name: JSM-6060LV), judging from the observed SEM image from directly above . A sample immediately after wiring processing in the manufacturing process of the printed wiring board (FIG. 8C) was used as a sample.
Each code is as follows.
○: No streak-like pattern, crater, or copper residue on the insulating layer surface ×: Streaky pattern, crater, or copper residue on the insulating layer surface

(3) Shape of thin copper foil during LS thin wire processing Using a scanning electron microscope (manufactured by JEOL Ltd., apparatus name: JSM-6060LV), determination is made from the observed SEM image from directly above. A sample immediately after wiring processing in the manufacturing process of the printed wiring board (FIG. 8C) was used as a sample.
Each code is as follows.
○: There is no skirt residue near the insulation layer of the wiring circuit ×: There is a skirt residue near the insulation layer of the wiring circuit

(4) ΔL = L1−L2
Using a scanning electron microscope (manufactured by JEOL Ltd., device name: JSM-6060LV), observe the cross-sectional shape of the wiring, calculate the maximum width of thin copper foil L1, and calculate the minimum width of electrical pattern plating L2. did. As a sample, a printed wiring board (FIG. 8C) was used.

(5) LS20 (L / S = 20 μm / 20 μm) line-to-line BHAST
The electrical insulation reliability between the fine wirings was evaluated by continuous measurement under the conditions of an applied voltage of 10 V and a temperature of 130 ° C. and a humidity of 85%. In addition, the printed wiring board (FIG.12 (b)) obtained in the said Example was used for the sample. The process was terminated when the insulation resistance value was less than 10 ⁸ Ω.
Each code is as follows.
○: 100 hours or more ×: Less than 100 hours.

This application claims priority based on Japanese Patent Application No. 2011-14127 filed on Jan. 26, 2011, the entire disclosure of which is incorporated herein.

Claims

Separating the carrier substrate from a laminate in which a copper foil with a carrier substrate is laminated on at least one surface of the insulating layer;
Forming a metal layer thicker than the copper foil on the entire surface or selectively on the copper foil;
Obtaining a conductive circuit pattern composed of the copper foil and the metal layer by etching at least the copper foil, and
In the step of obtaining the conductive circuit pattern, when measured according to JIS B0601, the Rp on the one surface of the insulating layer is 4.5 μm or less and the Rku is 2.1 or more. Method.
It is a manufacturing method of the printed wiring board according to claim 1,
Ra of the surface of the said copper foil facing the said one surface of the said insulating layer is a manufacturing method of a printed wiring board which is 1.0 micrometer or less.
It is a manufacturing method of the printed wiring board according to claim 1 or 2,
The said copper foil is a manufacturing method of a printed wiring board which has a crystal grain whose average length of a long side is 2 micrometers or less.
It is a manufacturing method of the printed wiring board according to claim 3,
The method for manufacturing a printed wiring board, wherein an area ratio occupied by the crystal grains having an average length of the long side of 2 μm or less is 80% or more in a cross-sectional view.
A method for manufacturing a printed wiring board according to any one of claims 1 to 4,
The manufacturing method of a printed wiring board whose 10-point average roughness (Rz) of the surface of the said carrier base material facing the surface of the said copper foil is 0.1 micrometer or more and 5.0 micrometers or less.
A method for manufacturing a printed wiring board according to any one of claims 1 to 5,
The step of forming the metal layer on the entire surface or selectively,
Forming a resist having an opening pattern on the copper foil;
Forming a plating layer to be the metal layer by plating in the opening pattern and on the copper foil;
Removing the resist, and
The said process of obtaining the said conductive circuit pattern is a manufacturing method of a printed wiring board including the process of carrying out the soft etching of the said copper foil.
A method for producing a printed wiring board according to any one of claims 1 to 6,
Before the step of forming the metal layer on the entire surface or selectively,
Forming a through hole or a non-through hole in the laminate; and
A step of bringing a chemical solution into contact with at least the inner wall of the through hole or the non-through hole;
And a step of forming an electroless plating layer on at least the copper foil and the inner wall of the through hole or the inner wall of the non-through hole by electroless plating.
An insulating layer;
Provided on one surface of the insulating layer, comprising a conductive circuit pattern composed of a copper foil and a metal layer,
A printed wiring board having an Rp of 4.5 μm or less and an Rku of 2.1 or more when measured according to JIS B0601.
The printed wiring board according to claim 8,
The printed wiring board in which the metal layer includes two or more plating films.
The printed wiring board according to claim 8 or 9,
In plan view, when the maximum width of the copper foil in the width direction orthogonal to the extending direction of the conductive circuit pattern is L1, and the minimum width of the metal layer is L2,
L1 is a printed wiring board which is the same as L2 or smaller than L2.
The printed wiring board according to claim 10,
A printed wiring board in which the area of the copper foil decreases from the first surface to the second surface of the copper foil in plan view.