JPWO2015151935A1 - Copper foil with carrier foil, copper-clad laminate and printed wiring board manufacturing method - Google Patents

Abstract

An object of the present invention is to provide a copper foil with a carrier foil suitable for the production of a copper clad laminate used for laser drilling. To achieve this object, a copper foil with a carrier foil having a layer structure of carrier foil / peeling layer / bulk copper layer, the maximum length of the copper composite compound on both surfaces of the copper foil with a carrier foil is 500 nm. Provided with a roughening treatment layer having a fine uneven structure formed by the following needle-like or plate-like convex portions, the roughening treatment layer provided on the surface of the carrier foil is used as a laser light absorption layer, The roughening layer provided on the surface of the bulk copper layer is used as an adhesive layer with the insulating layer constituting material, and provides a copper foil with a carrier foil.

Description

  The present application relates to a copper foil with a carrier foil, a copper clad laminate, and a printed wiring board.

  With the recent trend toward lighter and smaller mobile phones, mobile tools, notebook PCs and the like, printed wiring boards incorporated in these electronic devices have been demanded to be similarly light, thin, small and high-density. Multilayer printed wiring boards have come to be used in order to cope with such lightweight, thin, and high-density mounting on printed wiring boards.

  The multilayer printed wiring board includes a plurality of conductor layers, and the conductor layers are electrically connected to each other by interlayer conduction means such as through holes. In recent years, via holes have been used as interlayer conduction means instead of through holes in order to cope with higher density mounting and finer wiring. The through hole is generally formed by drilling, whereas the via hole is formed by laser processing. Therefore, the via hole has a smaller diameter compared to the through hole, which is advantageous for high-density mounting. As the via hole as the interlayer conduction means, various forms such as a blind via hole (BVH), an interstitial via hole (IVH), a stacking via hole and the like are known.

  In order to form a via hole, it is necessary to irradiate a conductor layer made of copper foil or the like with laser light. Copper foil is generally a mirror surface, and laser drilling is difficult because it reflects laser light. For this reason, the laser light irradiation surface is required to have good laser drilling performance. Furthermore, at the time of laser drilling, a splash phenomenon occurs in which droplets scattered around the opening are attached. When the splash phenomenon occurs, the portion where the droplets are attached around the opening becomes a protrusion. For this reason, when a copper plating layer is formed after drilling, abnormal deposition of the plating layer is caused at the projecting portion, and a defect such as a failure to form a desired circuit occurs. Therefore, when forming a via hole by laser processing, it is necessary to prevent adhesion of droplets due to the splash phenomenon.

  As a technique that takes the splash phenomenon into consideration, Patent Document 1 discloses that in the method of manufacturing a double-sided printed wiring board that requires interlayer conductive copper plating such as a through hole or a via hole or a multilayer printed wiring board having three or more layers, the print Copper foil with a peelable type carrier foil is used for the copper foil located on the outer layer of the wiring board, and the necessary processing of the through hole for the through hole or the hole for the via hole is performed without peeling off the carrier foil. Desmear the through hole for the through hole or the hole for the via hole, and perform interlayer conductive copper plating to ensure the electrical conduction of the through hole for the through hole or the hole for the via hole, and then peel off the carrier foil. The double-sided printed wiring is characterized in that the outer layer circuit pattern is registered on the copper foil located in the outer layer and then etched. A manufacturing method of a board or a multilayer printed wiring board having three or more layers "is disclosed.

  As disclosed in Patent Document 1, laser drilling is performed before the carrier foil is removed, and then the carrier foil is removed to remove the droplets attached to the periphery of the opening together with the carrier foil. Can do.

WO00 / 69238

  However, as in Patent Document 1 described above, when laser drilling is performed from the surface of the carrier foil of the copper foil with carrier foil in the outer layer of the multilayer laminate using a carbon dioxide laser, the thickness of the carrier foil is As the thickness increases, the laser drilling performance decreases, and there is a tendency that a via hole having a target opening diameter cannot be obtained.

  Therefore, as in Patent Document 1, a material excellent in laser drilling performance when performing drilling from the carrier foil surface of the copper foil with carrier foil in the outer layer of the multilayer laminate using a carbon dioxide laser is desired. Has been.

  Therefore, as a result of intensive studies by the present inventors, it was conceived that good laser drilling can be performed by using the copper foil with carrier foil described below. The outline of the invention relating to the present application will be described below.

<Copper foil with carrier foil>
The copper foil with a carrier foil according to the present application is a copper foil with a carrier foil having a layer configuration of carrier foil / peeling layer / bulk copper layer, and is composed of a copper composite compound on both sides of the copper foil with a carrier foil. A roughening treatment layer having a fine concavo-convex structure formed by needle-like or plate-like convex portions having a length of 500 nm or less is provided, and the roughening treatment layer provided on the surface of the carrier foil is used as a laser light absorption layer. The roughening treatment layer used on the surface of the bulk copper layer is used as an adhesive layer with the insulating layer constituting material.

<Copper-clad laminate>
The copper clad laminate according to the present application is characterized in that the adhesive layer side of the bulk copper layer of the copper foil with carrier foil according to the present application is laminated on at least one surface of the insulating layer constituting material.

<Printed wiring board>
The printed wiring board according to the present application is formed using the bulk copper layer of the copper foil with carrier foil according to the present application.

  The copper foil with carrier foil according to the present application has a fine concavo-convex structure formed by needle-like or plate-like convex portions having a maximum length of 500 nm or less made of a copper composite compound on both surfaces of the copper foil with carrier foil. The roughening process layer which has is provided. The roughening treatment layer provided on the surface of the carrier foil is used as a laser light absorption layer, and the roughening treatment layer provided on the surface of the bulk copper layer is used as an adhesive layer with the insulating layer constituting material. If the roughened layer provided on the surface of the bulk copper layer is bonded to the insulating layer constituting material as an adhesive layer, the maximum length of the copper composite compound is formed by needle-like or plate-like convex portions having a length of 500 nm or less. A copper clad laminate with a carrier foil provided with a roughened layer having a fine concavo-convex structure is obtained. If this copper clad laminate with carrier foil is used, good adhesion between the insulating layer constituting material and the bulk copper layer can be obtained. Moreover, since the roughening process layer provided in the surface of carrier foil absorbs a laser beam, it becomes possible to drill a carrier foil and a bulk copper layer simultaneously using a laser. And, by removing the carrier foil by peeling off after drilling, the splash around the opening of the hole formed by laser drilling can be removed together with the carrier foil, and a clean bulk copper layer can be exposed. it can. Therefore, the copper foil with carrier foil according to the present application can be suitably used when manufacturing a multilayer printed wiring board by the build-up method and the coreless build-up method. If the copper foil with carrier foil is used, the insulating layer It can provide high-quality printed wiring boards with good adhesion to components and eliminating defects caused by splash around the hole openings formed by laser drilling. It becomes like this.

It is a cross-sectional schematic diagram for showing the basic layer structure of the copper clad laminated board with a carrier foil which concerns on this application. It is a scanning electron microscope observation image for demonstrating the form of a roughening process layer in copper foil with a carrier foil which concerns on this application. It is a scanning electron microscope observation image which shows the cross section of the roughening process layer by which the laser beam is irradiated to the surface when applying the laser drilling method which concerns on this application. It is a cross-sectional schematic diagram for showing an image of laser drilling processing when forming a blind via hole using laser light. It is a cross-sectional schematic diagram for showing the manufacturing flow for showing the process of manufacturing a multilayer printed wiring board by a buildup method. It is a cross-sectional schematic diagram for showing the manufacturing flow for showing the process of manufacturing a multilayer printed wiring board by a buildup method. It is a cross-sectional schematic diagram for showing the manufacturing flow for showing the process of manufacturing a multilayer printed wiring board by a buildup method. 2 is a scanning electron microscope image of a linear circuit having a circuit width of 8 μm and an inter-circuit gap width of 8 μm obtained using the copper foil with a carrier foil for laser drilling obtained in Example 1. FIG.

  Hereinafter, the “form of the copper-clad laminate” and the “form of the printed wiring board” according to the present application will be described. In the “form of copper-clad laminate”, the “form of copper foil with carrier foil” according to the present application will also be described.

<Form of copper-clad laminate>
1. Concept of Layer Configuration of Copper Clad Laminate The copper clad laminate according to the present application has a layer configuration as shown in FIG. The copper clad laminate according to the present application is obtained by laminating the copper foil 11 with carrier foil according to the present application on at least one surface of the insulating layer constituting material 5. FIG. 1 (1 -A) shows the insulating layer constituting material. 5 shows an example in which the copper foil 11 with carrier foil according to the present application is laminated on both surfaces of FIG. 1, and FIG. 1 (1 -B) shows the carrier foil copper foil 11 according to the present application on one side of the insulating layer constituting material 5. The example which laminated | stacked is shown. In the example shown in FIG. 1 (1 -B), another copper foil 2 is laminated on the other surface side of the insulating layer constituting material 5. However, the copper clad laminate 1 shown in FIG. 1 is merely an example of the copper clad laminate according to the present application, and the invention according to the present application is not limited to the layer configuration shown in FIG.

1-1. First, the copper foil with carrier foil according to the present application will be described. The copper foil with carrier foil according to the present application has a layer configuration of “carrier foil 12 / peeling layer 13 / bulk copper layer 14” as shown in FIG. Roughening treatment provided on the surface of the carrier foil 12 with a “roughening treatment layer 4 having a fine concavo-convex structure formed by needle-like or plate-like convex portions having a maximum length of 500 nm or less made of a compound” The layer 4 is used as a laser light absorption layer, and the roughening treatment layer 4 provided on the surface of the bulk copper layer 14 is used as an adhesive layer with an insulating layer constituent material. In addition, both surfaces of the copper foil with carrier foil are the surface opposite to the side facing the release layer 13 of the carrier foil (hereinafter referred to as the outer surface of the carrier foil) and the release layer 13 of the bulk copper layer 14. This refers to the surface opposite to the side to be used (hereinafter referred to as the outer surface of the bulk copper layer). If a copper clad laminate is produced using the copper foil with carrier foil, the roughening layer on the bulk copper layer side can provide good adhesion with the insulating layer constituting material, and the carrier foil side roughness can be obtained. A copper-clad laminate with good laser drilling performance can be obtained by the treatment layer. Hereinafter, each component will be described.

Carrier foil: There is no particular limitation on the material of the carrier foil of the copper foil with carrier foil. However, it is considered to provide a “roughening treatment layer having a fine concavo-convex structure formed by needle-like or plate-like convex portions having a maximum length of 500 nm or less made of a copper composite compound” on the outer surface of the carrier foil. Then, the carrier foil is preferably a foil having a copper component on the surface, such as a copper foil or a resin film coated with copper on the surface.

  Moreover, there is no special limitation regarding the thickness of carrier foil. However, in the present invention, when laser drilling is performed, a roughening treatment layer provided on the outer surface of the carrier foil is used as the laser light absorption layer. For this reason, it is preferable that the thickness of the carrier foil be in the range of 7 μm to 18 μm, considering the ease of laser drilling, shortening the processing time, and reducing the material cost.

  As described above, the material and thickness of the carrier foil are not particularly limited, but the laser drilling workability when performing laser drilling by irradiating the surface of the roughened layer with laser light is not limited. From the viewpoint of being good, the outer surface of the carrier foil preferably has the following surface characteristics.

First, the outer surface of the carrier foil is “ratio of surface area (three-dimensional area: Aμm ² ) and two-dimensional area when a two-dimensional area of 57570 μm ² is measured by a laser method [(A) / (57570). The value of “surface area ratio (B)” calculated in the above formula is preferably 1.1 or more, and more preferably 1.5 or more. When the surface area ratio (B) is 1.1 or more, the laser drilling performance is good, and when it is 1.5 or more, it becomes even better. On the other hand, if the value of the surface area ratio (B) exceeds 3.0, the thickness of the carrier foil varies, and as a result, the laser hole diameter tends to vary. For this reason, the value of the surface area ratio (B) on the outer surface of the carrier foil is preferably 3.0 or less.

  The surface roughness (Rzjis) of the outer surface of the carrier foil is preferably 2.0 μm or more. A roughening treatment layer having the above-mentioned fine concavo-convex structure is provided on the outer surface of a carrier foil having a surface having a surface roughness (Rzjis) of 2.0 μm or more, and the roughening treatment layer is used as a laser light absorption layer. As a result, the laser drilling performance can be improved. The rougher the surface roughness of the outer surface of the carrier foil, the lower the reflectance of the laser beam on the outer surface of the carrier foil, and the better the laser drilling performance. On the other hand, when the surface roughness (Rzjis) is 6.0 μm or more, the thickness of the carrier foil varies, and as a result, the laser hole diameter tends to vary. For this reason, it is preferable that the surface roughness (Rzjis) of the outer surface of the carrier foil is 6.0 μm or less.

Release layer: The release layer of the copper foil with carrier foil used in the laser drilling method according to the present application is not particularly limited as long as the carrier foil can be peeled off later, and has the characteristics required for the release layer. As long as it is satisfactory, it may be either an “organic release layer” formed using an organic component or an “inorganic release layer” formed using an inorganic component.

  When employing an “organic release layer” as the release layer, use an organic component that contains at least one compound selected from the group consisting of a nitrogen-containing organic compound, a sulfur-containing organic compound, and a carboxylic acid. Is preferred. The nitrogen-containing organic compound here includes a nitrogen-containing organic compound having a substituent. Specifically, examples of the nitrogen-containing organic compound include 1,2,3-benzotriazole, carboxybenzotriazole, N ′, N′-bis (benzotriazolylmethyl) urea, which are triazole compounds having a substituent, and 1H. It is preferable to use -1,2,4-triazole and 3-amino-1H-1,2,4-triazole. And as a sulfur containing organic compound, it is preferable to use mercaptobenzothiazole, thiocyanuric acid, 2-benzimidazole thiol, etc. 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. This is because these organic components are excellent in high-temperature heat resistance, and it is easy to form a release layer having a thickness of 5 nm to 60 nm on the surface of the carrier foil.

  On the other hand, when an “inorganic release layer” is employed as the release layer, Ni, Mo, Co, Cr, Fe, Ti, W, P as an inorganic component, or a group consisting of an alloy or compound containing these as a main component It is possible to use at least one selected from In the case of these inorganic release layers, it can be formed using a known method such as an electrodeposition method, an electroless method, or a physical vapor deposition method.

  In the present application, both the organic release layer and the inorganic release layer can be preferably used, but when the heat is applied during lamination with the insulating layer constituting material, the appropriate peeling strength of the carrier foil is provided. It is preferable to use an organic release layer from the viewpoint of ensuring stability.

Bulk copper layer: The bulk copper layer of the copper foil with carrier foil used in the present application is not particularly limited as long as it is a copper foil that is detachably laminated with the carrier foil via the release layer. The method for producing the copper foil constituting the bulk copper layer is not particularly limited, and the copper foil can be produced by an electrolytic plating method, an electroless plating method, a vacuum deposition method, a sputtering deposition method, a chemical vapor reaction method, or the like. It can be produced by various methods including conventionally known methods. However, considering the production cost and the like, it is preferable to manufacture the bulk copper layer by electrolytic plating.

  The thickness of the bulk copper layer is not particularly limited as long as the thickness required when the copper layer is formed on a copper-clad laminate or a printed wiring board is sufficient. However, the copper foil with carrier foil according to the present application is provided with a roughened layer as a laser absorption layer on the outer surface of the carrier foil, and is a copper-clad laminate or a printed wiring board used for laser drilling. It can be suitably used as a production material. In consideration of such usage, the thickness of the bulk copper layer is preferably 0.1 μm to 9 μm. If the thickness of the bulk copper layer is 9 μm or less, three layers of “carrier foil / peeling layer / bulk copper layer” can be drilled simultaneously when the outer surface of the carrier foil is irradiated with laser light. On the other hand, if the thickness of the bulk copper layer exceeds 9 μm, the thickness of the entire copper foil with carrier foil becomes too thick, which is not preferable because the laser drilling performance deteriorates. On the other hand, if the thickness of the bulk copper layer is less than 0.1 μm, it is difficult to obtain a bulk copper layer having a uniform layer thickness, which is not preferable.

  Therefore, from the viewpoint of obtaining good laser drilling performance, the bulk copper layer is preferably thinner. Specifically, it is more preferably 5 μm or less, further preferably 3 μm or less, and most preferably 2 μm or less. Moreover, the thinner the bulk copper layer is, the more preferable it is for circuit formation using the bulk copper layer. On the other hand, from the viewpoint of obtaining a bulk copper layer having a more uniform layer thickness, the thickness of the bulk copper layer is more preferably 0.5 μm or more, and further preferably 1 μm or more.

  The surface characteristics of the bulk copper layer are not particularly limited. However, considering the fact that the copper foil with carrier foil is laminated on the insulating layer constituting material to form a copper-clad laminate and performing circuit formation using this copper-clad laminate, the surface characteristics of the outer surface of the bulk copper layer are Before the roughening treatment layer is provided, the following is preferable. The surface roughness (Rzjis) of the outer surface is preferably 2.0 μm or less, more preferably 1.5 μm or less, and further preferably 1.0 μm or less. Moreover, the glossiness (Gs60 °) of the outer surface of the bulk copper layer is preferably 100 or more, and more preferably 300 or more.

  By forming the fine concavo-convex structure on the outer surface of the bulk copper layer having the surface characteristics, it is possible to obtain a circuit having excellent high frequency characteristics while obtaining good adhesion to the insulating layer constituent material. That is, in a high frequency circuit, it is required to form a circuit on a conductor having a smooth surface in order to suppress transmission loss due to the skin effect. Here, when the roughening layer referred to in the present application is provided on the outer surface of the bulk copper layer, there is a concern about transmission loss of the high-frequency signal due to the uneven structure provided on the outer surface. However, as will be described later, since the fine concavo-convex structure is formed by a convex portion made of a copper composite compound containing copper oxide and cuprous oxide, a high-frequency signal is present in the roughening treatment layer made of the fine concavo-convex structure. Does not flow. For this reason, the said bulk copper layer shows the high frequency characteristic equivalent to the non-roughened copper layer which has not been roughened. Further, the roughened layer has good adhesion to the insulating material constituting the low dielectric constant used for the high frequency substrate. Therefore, the copper foil with carrier foil provided with the roughened layer having the fine concavo-convex structure on the outer surface of the bulk copper layer serving as the adhesive surface with the insulating layer constituting material is used for the circuit formation of the high-frequency circuit forming material and the printed wiring board. It is also suitable as a material.

1-2. Roughening treatment layer In the present application, both sides of the copper foil with carrier foil have “a fine concavo-convex structure formed by needle-like or plate-like convex portions having a maximum length of 500 nm or less made of a copper composite compound”. A roughening treatment layer is provided. Here, in the roughening layer provided on the outer surface of the carrier foil of the copper foil with carrier foil, and the roughening layer provided on the outer surface of the bulk copper layer, the fine irregularities constituting the roughening layer on each surface The shape and size of the structure can be common. In the following, when the roughening layer is described without particularly distinguishing between the roughening layer provided on the outer surface of the carrier foil and the roughening layer provided on the outer surface of the bulk copper layer, the explanation matters Is common to all roughening layers.

  The copper clad laminate with a carrier foil provided with the roughened layer having the fine concavo-convex structure on the outer surface of the carrier foil, the roughened layer can be used as a laser light absorbing layer, and the carrier foil, the bulk copper layer, Can be drilled at the same time. Moreover, since the roughening process layer which has this fine concavo-convex structure is provided in the outer surface of a bulk copper layer, the favorable adhesiveness of a bulk copper layer and an insulating-layer constituent material can be obtained. Furthermore, unlike the acicular crystals formed by the conventional blackening treatment, the roughened layer is not easily damaged even if other objects touch the surface, and the convex portions forming the fine uneven structure are not damaged. So-called powder fall does not occur. Therefore, the copper foil with carrier foil according to the present application has roughening treatment layers on both surfaces, that is, the outer surface of the carrier foil and the outer surface of the bulk copper layer, but is easy to handle without powder falling off.

  FIG. 2 shows the form of the surface of the roughened layer when the roughened layer referred to in the present application is provided on the surface of a general electrolytic copper foil that can be used as a carrier foil. Here, when an electrolytic copper foil is used as the carrier foil, it is optional to provide the bulk copper layer on either the electrode surface side or the deposition surface side of the electrolytic copper foil. Therefore, when the electrolytic copper foil is used as a carrier foil, it is arbitrary which surface on the electrode surface side or the deposition surface side is used as the outer surface, that is, the laser light irradiation surface. Accordingly, FIG. 2 shows that the surface of the roughened layer is roughened on the electrode surface side and the deposition surface side so that the surface state of the roughened layer can be grasped regardless of which surface is the laser light irradiation surface. The scanning electron microscope observed image when a process layer is formed is shown.

  As shown in FIG. 2, on the surface of each roughening treatment layer, fine convex portions protruding in a needle shape or plate shape are densely adjacent to each other, so that the surface of the electrolytic copper foil is extremely fine. An uneven structure is formed, and it is observed that these convex portions are provided so as to cover the surface of the electrolytic copper foil along the surface shape of the electrolytic copper foil.

  Here, when the surface of the roughening treatment layer on the electrode surface side is compared with the surface of the roughening treatment layer on the deposition surface side, the macroscopic surface shape of each surface is different. The difference in the macroscopic surface shape is considered to be caused by the difference in the macroscopic surface shape between the electrode surface and the deposition surface of the electrolytic copper foil itself before the fine uneven structure is formed. As described above, the electrode surface of the electrolytic copper foil becomes smooth because the surface shape of the cathode is transferred. On the other hand, the other surface side (deposition surface side) generally has an uneven shape formed by electrodeposition of copper. Referring to FIG. 2, the surface of the roughening treatment layer maintains the macroscopic surface shape of each surface of the electrolytic copper foil before the roughening treatment, and the electrode surface has a relatively smooth macroscopic surface shape. It can be seen that the deposited surface has a macroscopic surface shape with irregularities. This is because the needle-like or plate-like convex portion having a maximum length of 500 nm or less covers the surface of the electrolytic copper foil along the surface shape of the electrolytic copper foil before the roughening treatment. Since it is provided densely on the surface, it is considered that the macroscopic surface shape of each surface of the electrolytic copper foil is maintained even after the fine concavo-convex structure is formed.

  The fine concavo-convex structure is formed by convex portions having a maximum length of 500 nm or less. With reference to FIG. 2, the arrangement pitch at which the convex portions are arranged on the surface of the copper foil (electrolytic copper foil) is It is shorter than the length of each convex part. Here, in the case of laser drilling, a carbon dioxide laser having a dominant wavelength of 9.4 μm and 10.6 μm is used. Since the surface of the roughened layer has an arrangement pitch of the convex portions shorter than the emission wavelength of the carbon dioxide laser, the surface of the roughened layer suppresses the reflection of the laser beam by the carbon dioxide laser, and has a high light absorption. Absorbs laser light at a rate. For this reason, it can use suitably as a laser beam absorption layer. Moreover, the maximum length of the convex part which forms the said fine uneven structure is 500 nm or less, and is short compared with the length of the convex part formed by the conventional blackening process. The convex part formed by the conventional blackening process is thin and long protruding from the surface of the copper foil, so it is easy to be damaged when other objects come into contact with the surface, so-called powder falling during handling. It was happening. On the other hand, the fine concavo-convex structure referred to in the present application does not have a convex portion that is thin and long protruding from the surface of the copper foil as in the conventional blackening treatment. For this reason, even if an operator's finger touches the surface of the roughened layer during handling, the convex part forming the fine uneven structure is broken and the surface shape of the roughened layer is locally changed. In addition, the above-mentioned powder omission such as copper oxide fine powder splashing around does not occur, and handling can be facilitated.

  Next, the “maximum length” of the convex portion will be described with reference to FIG. FIG. 3 is a scanning electron microscope observation image showing a cross section of the copper foil with carrier foil referred to in the present application. However, FIG. 3 shows a cross section of the carrier foil-side copper foil on the carrier foil side. As shown in FIG. 3, in the cross section of the copper foil with carrier foil, a portion observed in a thin line shape is a convex portion. In FIG. 3, it is confirmed that the surface of the copper foil is covered with innumerable convex portions densely packed with each other, and each convex portion protrudes from the surface of the copper foil along the surface shape of the copper foil. In the present application, the “maximum length of the convex portion” means that when the length from the base end to the tip end of each convex portion observed in the shape of the line (line segment) in the cross section of the copper foil is measured. The maximum value of. Here, the roughening treatment layer on the outer surface of the carrier foil used as the laser light absorption layer has a higher laser light absorbance as the maximum length of the convex portion is longer, and the laser drilling performance is improved. In addition, the roughened layer on the outer surface of the bulk copper layer used as the adhesive layer with the insulating layer constituent material has a longer maximum length of the convex portion, and the insulating layer constituent material has a smaller anchor effect. Good adhesion can be obtained. On the other hand, in both the outer surface of the carrier foil and the outer surface of the bulk copper layer, handling is easier when the maximum length of the convex portion is shorter. This is because when another object comes into contact with the surface of the roughened layer, the shorter the maximum length of the convex portion, the less likely to be damaged. Moreover, the one where the maximum length of a convex-shaped part is shorter can maintain the surface shape of the copper foil before a roughening process, and can suppress the change of the surface roughness before and behind a roughening process. And it becomes possible to form a fine pitch circuit having a good etching factor equivalent to the case where the outer surface of the bulk copper layer is a so-called non-roughened copper layer. Therefore, from the standpoint of maintaining good laser drilling performance while obtaining a good etching factor with good adhesion to the insulating layer constituent material and making handling easier. The maximum length of the part is preferably 400 nm or less, and more preferably 300 nm or less. On the other hand, when the maximum length of the convex portion is less than 100 nm, the laser drilling performance is lowered and the adhesion with the insulating layer constituting material is also lowered. For this reason, it is preferable that the maximum length of the convex portion is 100 nm or more.

  Here, as shown in FIG. 3, the roughening process layer which consists of a fine uneven structure is visually recognized by the surface layer part of copper foil in layered form. The thickness of the roughening treatment layer corresponds to the length (height) in the thickness direction in which the convex portion protrudes from the surface of the copper foil. However, the length and the protruding direction of each convex portion forming the fine concavo-convex structure are not constant, and the protruding direction of each convex portion is not parallel to the thickness direction of the copper foil. Furthermore, the height of each convex portion varies. For this reason, the thickness of the roughened layer also varies. However, there is a certain correlation between the maximum length of the convex portion and the roughened layer, and as a result of repeated tests by the inventors, the average thickness of the roughened layer is 400 nm or less. In this case, the maximum length of the convex portion is 500 nm or less, and as described above, since there is no convex portion that protrudes long from the surface of the copper foil (carrier foil or bulk copper layer), the scratch resistance performance is high. It can be set as a roughening process layer. For this reason, handling becomes easy, good laser drilling without variation can be performed, and good adhesion between the bulk copper layer and the insulating layer constituting material can be obtained.

  Further, when the surface of the roughened layer is observed in a plane using a scanning electron microscope at an inclination angle of 45 ° and a magnification of 50000 times or more, other convex shapes among the convex portions adjacent to each other. It is preferable that the length of the tip portion that can be observed separately from the portion is 250 nm or less. Here, “the length of the tip portion that can be separately observed from other convex portions (hereinafter, may be abbreviated as“ the length of the tip portion ”)” refers to the length shown below. For example, when the surface of the roughened layer is observed with a scanning electron microscope, as described above with reference to FIG. 2, the convex portion protrudes in a needle shape or a plate shape on the surface of the roughened layer. Since the convex portions are densely provided on the surface of the copper layer, the base portion of the convex portion, that is, the interface between the convex portion made of the copper composite compound and the copper foil is observed from the surface of the copper layer. Can not do it. Therefore, when the roughened layer of the copper layer is observed in a plane as described above, one convex portion is separated from other convex portions among adjacent convex portions while being densely packed together. The portion that can be observed as being independently present is referred to as the “tip portion that can be observed separately from other convex portions”, and the length of the tip portion is the tip of the convex portion (that is, the tip) The length from the tip of the portion) to the position on the most proximal side that can be separated and observed from other convex portions.

  When the length of the tip portion of the convex portion is 250 nm or less, the maximum length of the convex portion is approximately 500 nm or less. As described above, when considering the laser drilling performance and the adhesion with the insulating layer constituent material, it is preferable that the maximum length of the convex portion is long in any case, and the length of the tip portion of the convex portion is also Longer is preferred. However, if the length of the tip portion of the convex portion is increased, it is likely to be damaged when another object comes into contact. Therefore, from the viewpoint of improving the scratch resistance and facilitating handling while maintaining good laser drilling performance and adhesion to the insulating layer constituent material, the length of the tip of the convex portion is longer. The thickness is preferably 200 nm or less, and more preferably 100 nm or less. On the other hand, when the length of the tip portion of the convex portion is less than 30 nm, the laser drilling performance is lowered and the adhesion with the insulating layer constituting material is also lowered. For this reason, it is preferable that the length of the front-end | tip part of the said convex-shaped part is 30 nm or more.

  Furthermore, it is preferable that the length of the tip portion of the convex portion is ½ or less with respect to the maximum length of the convex portion. When the ratio is 1/2 or less, the tip of the convex portion protrudes from the surface of the copper foil while being separated from other convex portions, so that the copper foil surface is densely covered with this fine uneven structure. can do.

Furthermore, the specific surface area (hereinafter simply referred to as “Kr adsorption specific surface area”) measured by adsorbing krypton on the surface of the fine concavo-convex structure in the roughened layer is 0.035 m ² / g or more. It is preferable to satisfy the conditions. When the Kr adsorption specific surface area is 0.035 m ² / g or more, the average height of the convex portion in the roughened layer is on the order of 200 nm, and stable laser drilling performance and scratch resistance performance can be stably achieved. This is because it can be secured. Here, although the upper limit of the Kr adsorption specific surface area is not defined, the upper limit is about 0.3 m ² / g, more preferably 0.2 m ² / g. Note that the Kr adsorption specific surface area at this time is a pretreatment by heating the sample at 300 ° C. for 2 hours using a specific surface area / pore distribution measuring device 3Flex manufactured by Micromeritics. Measured using krypton (Kr) as the adsorbed gas.

  Next, components constituting the fine uneven structure will be described. As described above, the convex portion is made of a copper composite compound. In the present application, from the viewpoint of good laser drilling performance, in the roughening layer as the laser light absorption layer, the copper composite compound is most preferably copper oxide, and copper oxide is the main component. In addition, cuprous oxide may be contained. In any case, a small amount of metallic copper may be contained.

  That is, the peak area of Cu (I) obtained when the constituent elements of the fine concavo-convex structure are analyzed using X-ray photoelectron spectroscopy (hereinafter simply referred to as “XPS”). The ratio of the peak area of Cu (I) to the total area with the peak area of Cu (II) (hereinafter referred to as the occupied area ratio) is 50% when the roughened layer is used as a laser light absorption layer. It is preferable that it is less than. On the other hand, when the roughened layer is used as an adhesive layer with the insulating layer constituent material, the exclusive area ratio of Cu (I) is preferably 50% or more.

  Here, a method for analyzing the constituent elements of the roughened layer by XPS will be described. When the constituent elements of the fine concavo-convex structure are analyzed by XPS, each peak of Cu (I) and Cu (II) can be separated and detected. However, when each peak of Cu (I) and Cu (II) is detected separately, the Cu (0) peak may be observed overlapping with the shoulder portion of the large Cu (I) peak. Thus, when the peak of Cu (0) is observed overlappingly, it shall be considered as a Cu (I) peak including this shoulder part. That is, in this invention, the constituent element of the copper composite compound which forms a fine concavo-convex structure using XPS is analyzed, Cu (I) appearing at 932.4 eV corresponding to the binding energy of Cu 2p 3/2, and 934. Each peak obtained by detecting the photoelectrons of Cu (II) appearing at 3 eV is separated into waveforms, and the occupation area ratio of the Cu (I) peak is specified from the peak areas of the respective components. However, Quantum 2000 (beam condition: 40 W, 200 μm diameter) manufactured by ULVAC-PHI Co., Ltd. is used as an XPS analyzer, and “MultiPack ver. 6.1A” is used as analysis software to perform state / semi-quantitative narrow measurement. be able to.

The Cu (I) peak obtained as described above is considered to be derived from monovalent copper constituting cuprous oxide (cuprous oxide: Cu ₂ O). And it is thought that a Cu (II) peak originates in the bivalent copper which comprises copper oxide (cupric oxide: CuO). Furthermore, it is considered that the Cu (0) peak is derived from zero-valent copper constituting metallic copper. Therefore, when the occupation area ratio of the Cu (I) peak is less than 50%, the proportion of cuprous oxide in the copper composite compound constituting the roughened layer is smaller than the proportion of copper oxide. In consideration of the laser drilling performance, the smaller the occupation ratio of the Cu (I) peak, the better. That is, the occupancy rate is less than 40%, less than 30%, less than 20%, etc., the smaller the value, the better the laser drilling performance, and the occupancy rate is 0%, that is, a fine uneven structure is formed. It is most preferable that the convex portion to be made of only copper oxide.

  On the other hand, when the roughened layer is provided on the outer surface of the bulk copper layer, the roughened layer on the outer surface of the bulk copper layer is the roughened layer on the outer surface of the carrier foil serving as the laser light irradiation surface. In contrast, the copper composite compound preferably contains copper oxide and cuprous oxide, and more preferably contains cuprous oxide as a main component. Specifically, in the roughened layer provided on the outer surface of the bulk copper layer, the Cu (I) peak occupancy is preferably 50% or more, more preferably 70% or more, More preferably, it is 80% or more, and particularly preferably 90% or more.

  When the occupied area ratio of the Cu (I) peak is less than 50%, after performing laser drilling on the copper layer and further forming a circuit by an etching method, a fine uneven structure is formed in the etching solution. The constituent components of are easily dissolved. This is because copper oxide has higher solubility in acids such as an etchant than cuprous oxide. Therefore, when the occupied area ratio of the Cu (I) peak is less than 50%, the adhesiveness between the copper layer and the insulating layer constituting material may be lowered later, which is not preferable.

  In the roughening layer on the outer surface of the bulk copper layer, the upper limit value of the occupied area ratio of the Cu (I) peak is not particularly limited, but is preferably 99% or less. There exists a tendency for the adhesiveness of a bulk copper layer and an insulating-layer constituent material to improve, so that the occupation area rate of a Cu (I) peak becomes low. Therefore, in order to obtain good adhesion between the two, the exclusive area ratio of the Cu (I) peak is preferably 98% or less, and more preferably 95% or less. Note that the occupied area ratio of the Cu (I) peak is calculated by a calculation formula of Cu (I) / {Cu (I) + Cu (II)} × 100 (%).

  The fine concavo-convex structure described above is formed, for example, by applying the following wet roughening treatment to both surfaces of the copper foil with carrier foil (that is, the outer surface of the carrier foil and the outer surface of the bulk copper layer). Can do. First, the copper composite compound which has copper oxide (cupric oxide) as a main component is formed in both surfaces of copper foil with a carrier foil by oxidizing on both surfaces of copper foil with carrier foil by a wet method. Thereby, “a fine concavo-convex structure formed from needle-like or plate-like convex portions” made of a copper composite compound containing copper oxide as a main component can be formed on both surfaces of the copper foil with carrier foil. Then, if necessary, a reduction treatment is performed, and copper oxide and cuprous oxide are contained by reducing part of the copper oxide to cuprous oxide (cuprous oxide) on both sides or one side of the copper foil with carrier foil. The “fine concavo-convex structure formed from needle-like or plate-like convex portions” made of a copper composite compound to be formed can be formed on both sides or one side of a copper foil with a carrier foil. Here, the “fine concavo-convex structure” itself referred to in the present application is formed at the stage of oxidation treatment. Therefore, in the case of forming a fine concavo-convex structure mainly composed of copper oxide or a fine concavo-convex structure made of copper oxide, the roughening process may be completed without performing a reduction process after the oxidation process. On the other hand, when forming a fine concavo-convex structure containing cuprous oxide at a certain ratio, a reduction treatment may be performed after the oxidation treatment. Even when the reduction treatment is performed, a part of the copper oxide can be reduced to cuprous oxide while maintaining the shape of the fine concavo-convex structure at the oxidation treatment stage. As a result, a “fine concavo-convex structure” made of a copper composite compound containing copper oxide and cuprous oxide can be formed. In this way, after performing oxidation treatment on both sides of the copper foil with carrier foil by a wet method or the like, if necessary, reduction treatment is performed to the extent necessary to form the “fine concavo-convex structure” as referred to in the present application. Can do. A small amount of metallic copper may be contained in a copper composite compound containing copper oxide as a main component or a copper composite compound containing copper oxide and cuprous oxide.

  For example, when performing the roughening treatment by the wet method, it is preferable to use an alkaline solution such as a sodium hydroxide solution. By oxidizing both sides of the copper foil with carrier foil using an alkaline solution, convex portions made of a copper composite compound mainly composed of needle-like or plate-like copper oxide are formed on both sides of the copper foil with carrier foil. be able to. Here, when both surfaces of the copper foil with carrier foil are oxidized with an alkaline solution, the convex portion grows long, and the maximum length may exceed 500 nm. It becomes difficult to form a structure. Therefore, in order to form the fine concavo-convex structure, it is preferable to use an alkaline solution containing an oxidation inhibitor capable of suppressing oxidation on both surfaces of the copper foil with a carrier foil.

  An example of such an oxidation inhibitor is an amino silane coupling agent. If an alkaline solution containing an amino silane coupling agent is used to oxidize both sides of the copper foil with carrier foil, the amino silane coupling agent in the alkaline solution is adsorbed on both sides of the copper foil with carrier foil. The oxidation by the alkaline solution can be suppressed. As a result, the growth of needle-like crystals of copper oxide can be suppressed, and extremely fine uneven structures can be formed on both surfaces of the copper foil with carrier foil.

  Specific examples of the amino silane coupling agent include N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, N-2- (aminoethyl) -3-aminopropyltrimethoxysilane, 3- Use of aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N- (1,3-dimethyl-butylidene) propylamine, N-phenyl-3-aminopropyltrimethoxysilane, etc. it can. All of these are dissolved in an alkaline solution and are stably held in the alkaline solution, and also exhibit an effect of suppressing oxidation on both sides of the copper foil with a carrier foil described above.

  As described above, the fine concavo-convex structure formed by subjecting both surfaces of the copper foil with a carrier foil to an oxidation treatment with an alkaline solution containing an amino-based silane coupling agent has a shape even after a reduction treatment. Almost maintained. As a result, a roughening treatment layer having a fine concavo-convex structure formed by needle-like or plate-like convex portions having a maximum length of 500 nm or less, including copper oxide and cuprous oxide, is formed. be able to. In the reduction treatment, Cu (I) obtained when qualitative analysis using XPS is performed on the constituent elements of the copper composite compound that forms the fine relief structure by adjusting the reducing agent concentration, solution pH, solution temperature, and the like. The area occupied by the peak of Cu (I) can be appropriately adjusted with respect to the total area of the peak area of Cu and the peak area of Cu (II). Also, for example, by immersing the copper foil with carrier foil in an alkaline solution, fine irregularities mainly composed of copper oxide on both surfaces of the copper foil with carrier foil, that is, the outer surface of the carrier foil and the outer surface of the bulk copper layer, respectively. If the structure is formed and then the reduction treatment is performed only on the roughened layer on the outer surface of the bulk copper layer, the laser light irradiation surface has a Cu (I) peak occupancy of 0%, and the insulating layer constituent material The bonding surface can be a copper foil with carrier foil having a Cu (I) peak occupancy of 50% or more. When the constituent elements of the fine concavo-convex structure formed by the above method are analyzed by XPS, the presence of “—COOH” is detected.

  As described above, since the oxidation treatment and the reduction treatment can be performed by a wet method, the fine concavo-convex structure is formed on both surfaces of the copper foil with a carrier foil by a method such as immersing the copper foil with a carrier foil in a treatment solution. be able to. Therefore, by using this wet method, forming a fine relief structure on both sides of the copper foil with a carrier foil improves the laser drilling processability on the laser light irradiation surface side, and the nano anchor effect by the fine relief structure Thus, the adhesion between the insulating layer constituting material and the bulk copper layer can be improved. Furthermore, as described above, the fine concavo-convex structure has high scratch resistance, so even if the fine concavo-convex structure is formed on both sides of the copper foil with carrier foil, handling is easy and prevents powder falling and the like. be able to.

1-3. Silane coupling agent treatment In copper foil with carrier foil, moisture resistance degradation when processed into a printed wiring board by providing a silane coupling agent treatment layer on the surface of the roughening treatment layer on the outer surface of the bulk copper layer. The characteristics can be improved. The silane coupling agent treatment layer provided on the roughened surface is composed of olefin functional silane, epoxy functional silane, vinyl functional silane, acrylic functional silane, amino functional silane and mercapto functional silane as a silane coupling agent. Either can be used to form. These silane coupling agents are represented by the general formula R—Si (OR ′) n (where R: an organic functional group represented by an amino group, a vinyl group, etc., OR ′: a methoxy group, an ethoxy group, etc. And n: 2 or 3).

  As a silane coupling agent here, vinyltrimethoxysilane, vinylphenyltrimethoxylane, γ-methacryloxypropyltrimethoxysilane, mainly used as a prepreg glass cloth for printed wiring boards, γ-glycidoxypropyltrimethoxysilane, 4-glycidylbutyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, N-3- (4- (3 -Aminopropoxy) ptoxy) propyl-3-aminopropyltrimethoxysilane, imidazole silane, triazine silane, 3-acryloxypropylmethoxysilane, γ-mercaptopropyltrimethoxysilane and the like can be used.

  The silane coupling agents listed here do not adversely affect the characteristics after becoming a printed wiring board. Which type is used in the silane coupling agent can be appropriately selected according to the use of the copper clad laminate.

  The above-mentioned silane coupling agent contains water as a main solvent and contains the silane coupling agent component in a concentration range of 0.5 g / L to 10 g / L so that the temperature is a room temperature level. It is preferable to use a liquid. When the concentration of the silane coupling agent in the silane coupling agent treatment liquid is less than 0.5 g / L, the adsorption rate of the silane coupling agent is slow, which is not suitable for general commercial profit, and the adsorption is not uniform. It becomes. On the other hand, even if the concentration of the silane cup agent exceeds 10 g / L, the adsorption rate is not particularly high, and the performance quality such as moisture absorption resistance is not particularly improved. .

  The method of adsorbing the silane coupling agent to the surface of the roughening treatment layer using this silane coupling agent treatment liquid can employ an immersion method, a showering method, a spraying method, and the like, and is not particularly limited. That is, any method can be used as long as the surface of the roughened layer and the silane coupling agent treatment liquid can be brought into contact with each other and adsorbed in accordance with the process design.

  After the silane coupling agent is adsorbed on the surface of the roughened layer, sufficient drying is performed, and a condensation reaction between the —OH group on the surface of the roughened layer and the adsorbed silane coupling agent is performed. Promote and completely evaporate the water resulting from the condensation. There is no special limitation regarding the drying method at this time. For example, even if an electric heater is used or a blast method that blows warm air is not particularly limited, a drying method and drying conditions corresponding to the production line may be employed. However, the silane coupling agent treatment described above is a treatment applied to the roughened layer on the outer surface of the bulk copper layer in order to improve the adhesion with the insulating layer constituent material, and the outer surface of the carrier foil. It is not necessary to apply to the roughened layer.

1-4. Lightness L ^{* of the} surface of the roughened layer
As described above, the needle-shaped or plate-shaped convex portions having a maximum length of 500 nm or less constituting the fine concavo-convex structure are arranged at a pitch shorter than the wavelength of the carbon dioxide laser and shorter than the wavelength range of visible light. ing. The light incident on the surface of the roughened layer is attenuated as a result of repeated irregular reflection within the fine concavo-convex structure. That is, the surface of the roughening treatment layer functions as a light absorption surface, and the surface of the roughening treatment layer is darkened to black, brown, or the like as compared with that before the roughening treatment. That is, the copper clad laminate according to the present application is also characterized by the color tone of the roughened layer on the outer surface of the carrier foil used as the laser light absorbing layer, and the brightness of the L ^* a ^* b ^* color system L ^* is 30 or less, more preferably 25 or less. When the value of the lightness L ^* exceeds 30 and a bright color tone is obtained, the maximum length of the convex portions constituting the fine concavo-convex structure may exceed 500 nm, which is not preferable. Further, when the value of the lightness L ^* exceeds 30, even when the maximum length of the convex portion is 500 nm or less, the convex portion is not provided sufficiently densely on the outer surface of the carrier foil. There is. That is, when the value of the lightness L ^* exceeds 30, the state of the roughening treatment may be insufficient, or the state of the roughening treatment may be uneven, and the bulk copper layer is lasered via the carrier foil. This is not a state suitable for drilling and is not preferable. When the lightness L ^* is 25 or less, the surface of the roughened layer becomes a more preferable state suitable for laser drilling. The lightness L ^* was measured using a spectral color difference meter SE2000 manufactured by Nippon Denshoku Industries Co., Ltd., and the whiteness attached to the measuring device was used for the lightness calibration in accordance with JIS Z8722: 2000. Then, a three measurements for the same site, the average of three lightness L ^* of the measurement data, and the lightness L ^* values referred to in the present application. In addition, also about the roughening process layer provided in the outer surface of a bulk copper layer, in order to obtain favorable adhesiveness with an insulating layer constituent material, the value of the brightness L ^* is the same as that of the roughening process layer provided on the outer surface of the carrier foil. It is the same. However, even when the above-mentioned silane coupling agent treatment is applied to the roughened layer provided on the outer surface of the bulk copper layer, the brightness L ^* value of the surface of the roughened layer varies before and after that. There is no.

2. Basic Concept of Laser Drilling Method Next, a method for performing laser drilling using the copper-clad laminate will be described with reference to FIG. Here, a case where laser drilling is performed on the copper-clad laminate 1 having the same layer configuration as that shown in FIG. 1 (1-A) will be described as an example. The copper-clad laminate 1 according to the present application is obtained by laminating the adhesive layer side of the bulk copper layer 14 of the copper foil 11 with carrier foil according to the present application on at least one surface of the insulating layer constituting material 5. Therefore, as shown to FIG. 4 (A), the surface (laser irradiation surface) by which a laser beam is irradiated becomes an outer surface of the carrier foil 12 of the copper foil 11 with carrier foil. Since the outer surface of the carrier foil 12 is provided with the roughening treatment layer having the fine uneven structure, the carrier foil 12 and the bulk copper layer 14 are simultaneously formed by irradiating laser light from the outer surface side of the carrier foil 12. Laser drilling can be performed. Thereafter, the carrier foil 12 is peeled off, so that the splash existing around the opening of the via hole formed by laser drilling is removed together with the carrier foil from the surface of the bulk copper layer, and the periphery of the opening is flat. A via hole 10 as shown in (B) can be formed.

  Here, the reason for improving the laser drilling performance by providing the roughening layer on the outer surface of the carrier foil serving as the laser light irradiation surface in the present application will be considered. First, by using the outer surface of the carrier foil as the roughening treatment layer, as described above, the surface of the roughening treatment layer becomes a black or brown matte surface and suppresses reflection of laser light. As a result, the thermal energy of the laser beam can be efficiently applied to the laser beam irradiation site. On the other hand, when the laser light irradiation surface of the copper clad laminate is a copper layer (referred to as carrier foil or bulk copper layer; hereinafter the same), the surface is subjected to roughening treatment, blackening treatment, or the like. Unless otherwise, the surface of the copper layer becomes a mirror surface, and the laser light is reflected, so that the thermal energy of the laser light cannot be efficiently applied to the laser light irradiation site.

The boiling point of copper is 2562 ° C, whereas the boiling points of copper oxide and cuprous oxide are 2000 ° C and 1800 ° C, respectively. Compared with copper, the boiling points of copper oxide and cuprous oxide are low. For this reason, when the surface of the roughening treatment layer is irradiated with laser light, the laser irradiation site on the surface of the roughening treatment layer reaches the boiling point earlier than in the case where the copper layer itself is a laser light irradiation surface. On the other hand, the thermal conductivity of copper is 354 W · m ⁻¹ · K ⁻¹ at 700 ° C., whereas the thermal conductivities of copper oxide and cuprous oxide are both 20 W · m ^{−1 at} 700 ° C. -K- ¹ or less. That is, the thermal conductivity of copper oxide and cuprous oxide is extremely small relative to the thermal conductivity of copper. On the other hand, the melting points of copper oxide and cuprous oxide are 1201 ° C. and 1235 ° C., respectively, whereas the melting point of copper is 1083 ° C., which is low. For this reason, compared with the case where copper layer itself is a laser beam irradiation surface, when a laser beam is irradiated to the surface of the said roughening process layer, the speed | rate which heat transfers to the outer side of a laser irradiation site | part becomes slow. As a result, heat can be concentrated in the depth direction, and the temperature of the carrier foil and the bulk copper layer can be easily made higher than the melting point. For this reason, by providing the fine concavo-convex structure made of the copper composite compound on the laser light irradiation surface, laser drilling can be performed more efficiently than when the copper layer itself is the laser light irradiation surface.

<Form of printed wiring board>
The printed wiring board according to the present application includes a copper layer formed using the bulk copper layer of the copper foil with carrier foil according to the present application, and is manufactured using the copper-clad laminate according to the present application. It may be. In the printed wiring board according to the present application, the copper layer is preferably provided with a via hole formed by laser drilling. For example, it can be set as the multilayer printed wiring board manufactured by the buildup process as shown in FIGS.

  Hereinafter, the form of the printed wiring board which concerns on this application is demonstrated, referring FIGS. 5-7 with a manufacturing method. However, the layer configuration and manufacturing method of the printed wiring board according to the present application are not limited to the forms described below, and the copper formed using the bulk copper layer of the copper foil with carrier foil according to the present application. Any form provided with a layer can be included.

  5 to 7 show an example of a manufacturing process of a multilayer printed wiring board by a so-called build-up method. For example, as shown in FIG. 5 (A), “carrier foil 12 / peeling layer 13 / bulk copper” are provided on both surfaces of an inner layer substrate 9 having an inner layer circuit 8 via an insulating layer constituting material 5 such as a prepreg / resin film. A copper foil 11 with a carrier foil having the layer configuration of “layer 14” is laminated to obtain a first build-up laminate 40 with a carrier foil. At this time, the copper foil 11 with carrier foil may be laminated only on one surface side of the insulating layer constituting material 5. In the example shown in FIG. 5A, an inner layer substrate 9 is provided with inner layer circuits 8 on both sides thereof, and filled vias (via holes) 10 for interlayer connection are formed. However, the inner layer substrate 9 is not limited to the form shown in FIG. 5A, and any layer configuration may be used.

  And as shown in FIG.6 (B), a laser drilling process is performed by irradiating the surface of the roughening process layer 4 of the carrier foil 12 of the 1st buildup laminated body 40 with a carrier foil with a laser beam. When this laser drilling process is completed, the carrier foil 12 is peeled off by the release layer 13 to remove all splashes present around the opening of the hole formed by the laser drilling process, and a clean bulk without splashing. The surface of the copper layer 14 is exposed, and the first buildup layer-equipped laminate 41 shown in FIG. In the case of the first build-up laminate 40 with carrier foil shown in FIG. 6 (B), the carrier foil 12 provided with the roughening treatment layer 4 having the fine uneven structure is present on both surfaces thereof. Laser drilling can be easily performed from both surfaces of the first build-up laminate 40 with carrier foil. And the desmear process for removing the resin residue produced by the laser drilling process is performed, the inside of the via hole is plated and filled to form the filled via 10, and the plated layer 24 is formed on the surface of the bulk copper layer. And the laminated body 42 with the 1st buildup wiring layer shown in FIG.7 (D) can be formed by forming the 1st buildup wiring layer 31 by carrying out an etching process.

  Further, when the copper foil 11 with carrier foil is laminated on both surfaces of the laminate 42 with the first buildup wiring layer shown in FIG. 7D via the insulating layer constituting material 5 such as a prepreg / resin film, FIG. It becomes the 2nd buildup laminated body 43 with a carrier foil provided with the 2nd buildup wiring layer 32 shown to (E). In this way, the same operation as in FIG. 6B, FIG. 6C, and FIG. 7D is repeated as necessary to build the nth circuit pattern layer (n ≧ 3: integer). It can also be laminated up. At this time, instead of using the insulating layer constituting material 5 and the above-described copper foil 11 with carrier foil having the layer constitution of “carrier foil 12 / peeling layer 13 / bulk copper layer 14”, the outer surface of the bulk copper layer 14 It is also preferable to use a copper foil with a carrier foil with a resin layer provided with a resin layer for constituting an insulating layer.

  The multi-layer laminate after the final lamination is subjected to laser drilling if necessary, desmear treatment for removing the resin residue generated by laser drilling, and plating filling in the via hole A filled via is formed, and a plated layer is formed on the surface of the bulk copper layer, and then the outer copper layer is etched to form an outer layer circuit to form a multilayer printed wiring board.

  The printed wiring board according to the present application is manufactured by using the copper foil 11 with carrier foil according to the present application, and then laser drilling is performed by peeling the carrier foil 12 with the release layer 13 after the laser drilling process. All splashes present around the opening of the via hole formed in (1) can be removed. Therefore, plating filling and circuit formation in the via hole can be performed by plating processing, etching processing or the like in a state where the surface of the bulk copper layer around the opening of the via hole is clean. Further, the roughened layer 4 on the outer surface of the bulk copper layer 14 makes it possible to obtain good adhesion to the insulating layer constituting material 5 constituting the interlayer insulating layer.

  Hereinafter, the technical superiority when a copper-clad laminate and a printed wiring board are manufactured using the copper foil with a carrier foil according to the present application will be described through Examples and Comparative Examples.

  A copper foil with a carrier foil according to the present application was produced as follows. First, an untreated copper foil with a carrier foil having a layer configuration of “carrier foil / peeling layer / bulk copper layer” was prepared. As the untreated copper foil with carrier foil, the surface roughness (Rzjis) of the outer surface of the carrier foil is 5.3 μm, the glossiness [Gs (60 °)] is 2.1, and the thickness of the carrier foil is The thickness was 12 μm, the thickness of the bulk copper layer was 1.5 μm, and the release layer was made of an organic release layer containing 1,2,3-benzotriazole. The carrier according to the present application in which the outer surface of the carrier foil of the copper foil with untreated carrier foil and the outer surface of the bulk copper layer are subjected to surface treatment in the following procedure, and the roughened layer is provided on both surfaces thereof. A copper foil with foil was obtained. In addition, the measuring method of surface roughness, surface area ratio, and glossiness is as follows.

(Measurement of roughness)
Using a stylus type surface roughness meter SE3500 manufactured by Kosaka Laboratory, surface roughness was measured according to JIS B 0601-2001.

[Measurement of surface area ratio]
The surface area ratio (B) was calculated | required according to the calculation formula mentioned above based on the surface area A when using a KEYENCE laser microscope VK-X100 and measuring the two-dimensional area | region of 57570 micrometers ² by the laser method.

[Glossiness measurement]
Glossiness was measured using a gloss meter PG-1M manufactured by Nippon Denshoku Industries Co., Ltd., in accordance with JIS Z 8741-1997, which is a method for measuring glossiness.

  This copper foil with carrier foil was subjected to a pretreatment and then a roughening treatment. Hereinafter, it demonstrates in order.

Pretreatment: The copper foil with carrier foil was immersed in an aqueous sodium hydroxide solution, degreased with alkali, and washed with water. And this alkali-degreasing copper foil with a carrier foil was immersed in a sulfuric acid aqueous solution having a sulfuric acid concentration of 5 mass% for 1 minute, and then washed with water.

Roughening treatment: The copper foil with carrier foil subjected to the preliminary treatment was subjected to an oxidation treatment. In the oxidation treatment, the copper foil 11 with the carrier foil is subjected to a liquid temperature of 70 ° C., pH = 12, chlorous acid concentration of 150 g / L, N-2- (aminoethyl) -3-aminopropyltrimethoxysilane concentration of 10 g / L. A copper compound containing copper oxide was formed on both surfaces of the copper foil with carrier foil 11 by immersing in a sodium hydroxide solution containing a predetermined oxidation treatment time (1 minute, 2 minutes, 4 minutes, 10 minutes).

  Next, the copper foil with carrier foil after the oxidation treatment was reduced by dipping for 1 minute in an aqueous solution (room temperature) having a dimethylamine borane concentration of 20 g / L adjusted to pH = 12 using sodium carbonate and sodium hydroxide. Treated, washed with water and dried. Through these steps, four types of copper foils with carrier foil were obtained which were provided with the fine relief structure according to the present application on the outer surface of the carrier foil and the outer surface of the bulk copper layer.

Using these four types of copper foils with carrier foil as samples, the surface of the roughened layer of the carrier foil of each sample was qualitatively analyzed using XPS. As a result, the presence of “copper oxide” and “cuprous oxide” was clearly confirmed in all samples. Table 1 shows the occupied area ratio of the peak of Cu (I) with respect to the total area of the peak area of Cu (I) and the peak area of Cu (II) of each sample. As a result of this qualitative analysis, the presence of “—COO group” was clearly confirmed in all samples. Table 1 summarizes the Kr adsorption specific surface area and brightness L ^* of the surface of the roughened layer on the outer surface of the carrier foil of each sample, together with the occupied area ratio of the peak of Cu (I). In Table 1, “Kr adsorption specific surface area” is simply indicated as “specific surface area”.

  Further, the above four types of samples were brought into contact with both surfaces of the insulating layer constituting material, and were laminated using a vacuum press machine under conditions of a press pressure of 3.9 MPa, a temperature of 220 ° C., and a press time of 90 minutes. However, prepreg GFPL-830NS manufactured by Mitsubishi Gas Chemical Co., Ltd. was used as the insulating layer constituent material. This obtained the copper clad laminated board which provided the copper foil with carrier foil on both surfaces of the insulating layer structural material.

  Furthermore, after laminating the above-mentioned four kinds of samples on one side of the insulating layer constituting material by the above-described method, the carrier foil is peeled off, and a plated copper layer is adhered and formed on the exposed bulk copper layer to form a copper layer having a thickness of 18 μm. The copper clad laminated board provided with this was produced. And the test substrate provided with the linear circuit for 0.4 mm width peeling strength measurement was produced by the etching method using the said sample. And the peeling strength of each test board | substrate was measured based on JISC6481 (1996).

In Example 2, the same untreated copper foil with carrier foil as in Example 1 was used, and oxidation treatment was performed on both surfaces of the untreated copper foil with carrier foil (pretreatment time was 2 minutes). After the treatment, the outer surface of the carrier foil was not subjected to the reduction treatment, and only the outer surface of the bulk copper layer was subjected to the reduction treatment by shower spraying the same reduction treatment solution as in Example 1. In the same manner as in Example 1, a copper foil with carrier foil provided with the fine concavo-convex structure according to the present application on the outer surface of the carrier foil and the outer surface of the bulk copper layer was obtained. Then, in the same manner as in Example 1, the occupied area ratio of the peak of Cu (I) with respect to the total area of the peak area of Cu (I) and the peak area of Cu (II) on each surface, the roughness of the carrier foil The Kr adsorption specific surface area and brightness L ^* of the surface of the chemical treatment layer were determined. The results are shown in Table 1. In addition, also about the copper foil with a carrier foil of Example 2, presence of "-COO group" was confirmed clearly. Further, a copper clad laminate was obtained in the same manner as in Example 1, a test substrate for measuring the peel strength was produced, and the peel strength was measured.

Comparative example

[Comparative Example 1]
In Comparative Example 1, the same copper foil with carrier foil as in Example 1 was used, and the outer surface of the carrier foil was not subjected to the roughening treatment, and the conventional roughening treatment (copper sulfate type) was applied only to the outer surface of the bulk copper layer. (Roughening treatment using fine copper particles formed with a copper electrolyte). A copper clad laminate was obtained in the same manner as in Example 1 using the copper foil with carrier foil of Comparative Example 1 thus obtained.

[Comparative Example 2]
In Comparative Example 2, the same untreated copper foil with carrier foil as in Example 1 was used, the same pretreatment as in Example 1 was performed, blackening treatment was performed on both sides, reduction treatment was further performed, and the outer surface of the carrier foil And the copper foil with a carrier foil provided with the conventional reduction | restoration blackening process layer on the outer surface of the bulk copper layer was obtained. Hereinafter, the procedure of the blackening process and the reduction process will be described.

Blackening treatment: A general blackening treatment was performed on the copper foil with carrier foil after the preliminary treatment. In the oxidation treatment, an oxidation treatment solution manufactured by Rohm & Haas Electronic Materials Co., Ltd., “PRO BOND 80A OXIDE SOLUTION” 10 vol%, “PRO BOND 80B OXIDE SOLUTION” 20 vol% in an aqueous solution at a temperature of 85 ° C. for 5 minutes. Immersion and blackening treatment.

Reduction treatment: Reduction treatment was performed on the copper foil with carrier foil that had been subjected to blackening treatment. In the reduction treatment, an aqueous solution containing 35 vol.% Of “CIRCUPOSIT PB OXIDE CONVERTER 60C” 6.7 vol% and “CUPOSIT Z” 1.5 vol%, which is a reduction treatment liquid manufactured by Rohm & Haas Electronic Materials Co., Ltd. It was immersed for a minute, washed with water and dried. Through these steps, a copper foil with a carrier foil provided with a general reduction blackening treatment layer was obtained. Then, in the same manner as in Example 1, the occupied area ratio of the peak of Cu (I) with respect to the total area of the peak area of Cu (I) and the peak area of Cu (II) on each surface, the roughness of the carrier foil The Kr adsorption specific surface area and brightness L ^* of the surface of the chemical treatment layer were determined. The results are shown in Table 1.

  Moreover, using the copper foil with a carrier foil obtained as described above, a copper clad laminate was obtained in the same manner as in Example 1, and a test substrate for measuring the peel strength was prepared, and the peel strength was obtained. Was measured.

[Evaluation results]
Table 1 below shows the specific surface area, lightness L ^* , and outer surface of the bulk copper layer of the fine concavo-convex structure formed on the surface of the carrier foil of the copper foil with carrier foil obtained in Example 1, Example 2 and Comparative Example 2. The measurement result regarding the peeling strength when the roughening process layer side of this is laminated | stacked on the insulating layer structural material is shown. FIG. 8 shows a scanning electron microscope observation image of a linear circuit having a circuit width of 8 μm and an inter-circuit gap width of 8 μm manufactured using the carrier foil-attached copper foil obtained in Example 1.

As can be understood from Table 1, even if the oxidation treatment time fluctuates between 1 minute and 10 minutes, the convex portions of fine irregularities formed on the outer surface of the carrier foil of the copper foil with carrier foil according to the example The maximum length is 500 nm or less, and there is no difference in the content detected in the qualitative analysis of fine irregularities. Further, the value of the lightness L ^* of the surface of the roughened layer is 18 to 25, which is a very small value. On the other hand, the value of the Kr adsorption specific surface area increases in proportion to the increase in the oxidation treatment time. Therefore, when the adhesion layer side of the outer surface of the bulk copper layer of the copper foil with four types of carrier foils is laminated on the insulating layer constituting material and the peel strength is measured, even with the shortest oxidation treatment time, It can be seen that a practically sufficient peel strength is obtained, and a peel strength proportional to the value of the Kr adsorption specific surface area is obtained. From this, it can be understood that the oxidation treatment time employed in the examples is appropriate.

Comparison between Example and Comparative Example 1: Here, laser drilling performance is examined. Irradiating a laser beam from the carrier foil side with a carbon dioxide laser as a laser light source on the copper-clad laminate using the copper foil with carrier foil obtained in Example and the copper-clad laminate obtained in Comparative Example 1 did. At this time, the mask diameter is 2.0 mm and the pulse width is 14 μsec. The laser irradiation conditions of pulse energy 19.3mJ, offset 0.8, laser beam diameter 153μm are adopted, and a hole with a processing diameter of 60μm is planned to be formed in the bulk copper layer of the copper clad laminate with carrier foil. A 100-shot via hole formation test was performed on each copper-clad laminate. Then, after laser irradiation, the carrier foil was removed, and when the hole diameter formed in the bulk copper layer was 60 μm or more, it was determined that the processing was performed satisfactorily. The results are shown in Table 2.

  As can be seen from Table 2, in the case of the example, it can be determined that all the laser-clad laminates have been subjected to good laser drilling. On the other hand, in the case of Comparative Example 1, it was difficult to drill the carrier foil and the bulk copper layer at the same time under the same laser processing conditions applied to the example. The aperture ratio in Table 2 is the ratio of the number of shots in which a laser shot was made by conducting a 100-shot via hole formation test. The opening diameter distribution is a distribution width when the opening diameter of a via hole obtained in a 100-shot via hole formation test is measured.

Comparison between Example and Comparative Example 2 When the laser drilling performance of Comparative Example 2 was evaluated in the same manner as described above, the laser drilling performance of the copper-clad laminate of Comparative Example 2 was equivalent to that of the Example. It was. However, in the copper-clad laminate of Comparative Example 2, there was a tendency that scratches, scratches, etc. were likely to occur on the surface of the reduction blackening treatment layer on the outer surface of the carrier foil. The surface of the reduced blackening treatment layer where scratches or abrasions were generated was glossy. When the surface of the reduction blackening layer was glossy, the laser drilling performance was remarkably deteriorated, and laser drilling could not be performed on the copper-clad laminate. On the other hand, the copper foil with carrier foil for laser drilling according to the present application did not cause scratches or rubbing, and the laser drilling performance was not deteriorated.

  Further, using the copper foil with carrier foil for laser drilling obtained in Example 1 and the copper foil with carrier foil used in Comparative Examples 1 and 2, the MSAP (Modified Semi Additive Process) method is used. Thus, an attempt was made to form a linear circuit having a circuit height of 12 μm, a circuit width of 8 μm and an inter-circuit gap width of 8 μm. As a result, in the case of the copper-clad laminate using the carrier foil-attached copper foil obtained in the example, the scanning electron microscope observation image shown in FIG. 8 (FIG. 8A is a perspective observation image, FIG. 8B) As can be seen from the cross-sectional observation image), the above linear circuit was obtained. On the other hand, in the case of the copper clad laminates obtained in Comparative Example 1 and Comparative Example 2, the etching time was longer than that in Examples, and the linear circuit could not be obtained. This is because it takes time to completely remove the fine copper grains and the reduced blackening layer by etching, during which time circuit erosion progresses, the circuit height decreases, and the circuit width also decreases. Therefore, it can be understood that it is difficult to form a circuit having a circuit width of 8 μm / inter-circuit gap width of 8 μm by the conventionally known fine copper grains or the roughening process by reduction blackening process.

  By using the copper foil with carrier foil according to the present application, it is possible to remove all the splash around the hole opening formed by laser drilling and provide a copper-clad laminate with a clean copper layer It becomes. As a result, it is possible to provide a high-quality multilayer printed wiring board by eliminating defects caused by the splash. Further, in the copper foil with carrier foil according to the present application, the roughened layer of the carrier foil and the bulk copper layer is “formed by a needle-like or plate-like convex portion having a maximum length of 500 nm or less made of a copper composite compound. By using the “fine concavo-convex structure”, it becomes possible to form a fine pitch circuit more than conventional. And, if the copper foil with carrier foil according to the present application is used, it is possible to manufacture a multilayer printed wiring board by a build-up method and a coreless build-up method without requiring a process change of the conventional manufacturing method, and a high quality A printed wiring board can be provided.

DESCRIPTION OF SYMBOLS 1 (with carrier foil) Copper clad laminated board 2 Copper foil 3 Roughening surface 4 on the electrode surface side Roughening surface 5 on the deposition surface side Insulating layer constituent material 8 Inner layer circuit 9 Inner layer substrate 10 Filled via (via hole)
11 Copper foil with carrier foil 12 Carrier foil 13 Release layer 14 Bulk copper layer 23 First buildup wiring circuit 24 Plating layer 31 First buildup wiring layer 32 Second buildup wiring layer 40 First buildup laminate with carrier foil 41 Laminated body with first buildup layer 42 Laminated body with first buildup wiring layer 43 Second buildup laminated body with carrier foil

<Copper foil with carrier foil>
The copper foil with a carrier foil according to the present application is a copper foil with a carrier foil having a layer configuration of carrier foil / peeling layer / bulk copper layer, and is composed of a copper composite compound on both sides of the copper foil with a carrier foil. comprising a roughened layer length having a fine uneven structure formed by the convex portion of 100nm or 500nm or less needle-like or plate-like, roughened layer provided on the surface of the carrier foil, copper oxide The roughening layer provided on the surface of the bulk copper layer includes a copper oxide and a cuprous oxide. It has the fine concavo-convex structure made of a copper composite compound, and is used as an adhesive layer with an insulating layer constituent material.

<Copper-clad laminate>
Copper-clad laminate according to the present application is characterized in that the adhesive layer side of the bulk copper layer of the carrier foil coated copper foil according to the present application is laminated on at least one surface of the insulating layer constituting material.

<Printed wiring board>
The printed wiring board which concerns on this application is provided with the copper layer formed using the said bulk copper layer of the copper foil with a carrier foil which concerns on this application.

The copper foil with carrier foil according to the present application is a fine unevenness formed on both surfaces of the copper foil with carrier foil by needle-like or plate-like convex portions having a maximum length of 100 to 500 nm made of a copper composite compound. A roughening treatment layer having a structure is provided. The roughening layer provided on the surface of the carrier foil has a fine concavo-convex structure made of a copper composite compound containing copper oxide as a main component, is used as a laser light absorption layer, and is applied to the surface of the bulk copper layer. The provided roughening treatment layer has a fine concavo-convex structure made of a copper composite compound containing copper oxide and cuprous oxide, and is used as an adhesive layer with the insulating layer constituent material. If the roughening layer provided on the surface of the bulk copper layer is adhered to the insulating layer constituting material as an adhesive layer, the needle-like or plate-like convex part having a maximum length of 100 to 500 nm made of a copper composite compound A copper clad laminate with a carrier foil provided with a roughening treatment layer having a fine concavo-convex structure formed by the above is obtained. If this copper clad laminate with carrier foil is used, good adhesion between the insulating layer constituting material and the bulk copper layer can be obtained. Moreover, since the roughening process layer provided in the surface of carrier foil absorbs a laser beam, it becomes possible to drill a carrier foil and a bulk copper layer simultaneously using a laser. And, by removing the carrier foil by peeling off after drilling, the splash around the opening of the hole formed by laser drilling can be removed together with the carrier foil, and a clean bulk copper layer can be exposed. it can. Therefore, the copper foil with carrier foil according to the present application can be suitably used when manufacturing a multilayer printed wiring board by the build-up method and the coreless build-up method. If the copper foil with carrier foil is used, the insulating layer It can provide high-quality printed wiring boards with good adhesion to components and eliminating defects caused by splash around the hole openings formed by laser drilling. It becomes like this.

1-1. First, the copper foil with carrier foil according to the present application will be described. The copper foil with carrier foil according to the present application has a layer configuration of “carrier foil 12 / peeling layer 13 / bulk copper layer 14” as shown in FIG. A roughening treatment layer 4 having a fine concavo-convex structure formed by needle-like or plate-like convex portions having a maximum length of 100 nm or more and 500 nm or less made of a compound, and provided on the surface of the carrier foil 12. The roughening treatment layer 4 has a fine concavo-convex structure made of a copper composite compound containing copper oxide as a main component, is used as a laser light absorption layer, and the roughening treatment layer 4 provided on the surface of the bulk copper layer 14 is It has a fine concavo-convex structure made of a copper composite compound containing copper oxide and cuprous oxide, and is used as an adhesive layer with an insulating layer constituting material. In addition, both surfaces of the copper foil with carrier foil are the surface opposite to the side facing the release layer 13 of the carrier foil (hereinafter referred to as the outer surface of the carrier foil) and the release layer 13 of the bulk copper layer 14. This refers to the surface opposite to the side to be used (hereinafter referred to as the outer surface of the bulk copper layer). If a copper clad laminate is produced using the copper foil with carrier foil, the roughening layer on the bulk copper layer side can provide good adhesion with the insulating layer constituting material, and the carrier foil side roughness can be obtained. A copper-clad laminate with good laser drilling performance can be obtained by the treatment layer. Hereinafter, each component will be described.

Carrier foil: There is no particular limitation on the material of the carrier foil of the copper foil with carrier foil. However, a “roughening treatment layer having a fine concavo-convex structure formed by needle-like or plate-like convex portions having a maximum length of 100 nm to 500 nm made of a copper composite compound” is provided on the outer surface of the carrier foil. In view of the above, the carrier foil is preferably a foil having a copper component on its surface, such as a copper foil or a resin film coated with copper on the surface.

1-2. Roughening treatment layer In this application, on both sides of the copper foil with carrier foil, “a fine concavo-convex structure formed by needle-like or plate-like convex portions having a maximum length of 100 to 500 nm made of a copper composite compound” A roughening treatment layer is provided. Here, in the roughening layer provided on the outer surface of the carrier foil of the copper foil with carrier foil, and the roughening layer provided on the outer surface of the bulk copper layer, the fine irregularities constituting the roughening layer on each surface The shape and size of the structure can be common. In the following, when the roughening layer is described without particularly distinguishing between the roughening layer provided on the outer surface of the carrier foil and the roughening layer provided on the outer surface of the bulk copper layer, the explanation matters Is common to all roughening layers.

Next, the “maximum length” of the convex portion will be described with reference to FIG. FIG. 3 is a scanning electron microscope observation image showing a cross section of the copper foil with carrier foil referred to in the present application. However, FIG. 3 shows a cross section of the carrier foil-side copper foil on the carrier foil side. As shown in FIG. 3, in the cross section of the copper foil with carrier foil, a portion observed in a thin line shape is a convex portion. In FIG. 3, it is confirmed that the surface of the copper foil is covered with innumerable convex portions densely packed with each other, and each convex portion protrudes from the surface of the copper foil along the surface shape of the copper foil. In the present application, the “maximum length of the convex portion” means that when the length from the base end to the tip end of each convex portion observed in the shape of the line (line segment) in the cross section of the copper foil is measured. The maximum value of. Here, the roughening treatment layer on the outer surface of the carrier foil used as the laser light absorption layer has a higher laser light absorbance as the maximum length of the convex portion is longer, and the laser drilling performance is improved. In addition, the roughened layer on the outer surface of the bulk copper layer used as the adhesive layer with the insulating layer constituent material has a longer maximum length of the convex portion, and the insulating layer constituent material has a smaller anchor effect. Good adhesion can be obtained. On the other hand, in both the outer surface of the carrier foil and the outer surface of the bulk copper layer, handling is easier when the maximum length of the convex portion is shorter. This is because when another object comes into contact with the surface of the roughened layer, the shorter the maximum length of the convex portion, the less likely to be damaged. Moreover, the one where the maximum length of a convex-shaped part is shorter can maintain the surface shape of the copper foil before a roughening process, and can suppress the change of the surface roughness before and behind a roughening process. And it becomes possible to form a fine pitch circuit having a good etching factor equivalent to the case where the outer surface of the bulk copper layer is a so-called non-roughened copper layer. Therefore, from the standpoint of maintaining good laser drilling performance while obtaining a good etching factor with good adhesion to the insulating layer constituent material and making handling easier. The maximum length of the part is preferably 400 nm or less, and more preferably 300 nm or less. On the other hand, when the maximum length of the convex portion is less than 100 nm, the laser drilling performance is lowered and the adhesion with the insulating layer constituting material is also lowered. Therefore, the maximum length of the convex portion is not less than 100 nm.

Furthermore, the specific surface area (hereinafter simply referred to as “Kr adsorption specific surface area”) measured by adsorbing krypton on the surface of the fine concavo-convex structure in the roughened layer is 0.035 m ² / g. It is preferable to satisfy the above conditions. When the Kr adsorption specific surface area is 0.035 m ² / g or more, the average height of the convex portion in the roughened layer is on the order of 200 nm, and stable laser drilling performance and scratch resistance performance can be stably achieved. This is because it can be secured. Here, although the upper limit of the Kr adsorption specific surface area is not defined, the upper limit is about 0.3 m ² / g, more preferably 0.2 m ² / g. Note that the Kr adsorption specific surface area at this time is a pretreatment by heating the sample at 300 ° C. for 2 hours using a specific surface area / pore distribution measuring device 3Flex manufactured by Micromeritics. Measured using krypton (Kr) as the adsorbed gas.

As described above, the fine concavo-convex structure formed by subjecting both surfaces of the copper foil with a carrier foil to an oxidation treatment with an alkaline solution containing an amino-based silane coupling agent has a shape even after a reduction treatment. Almost maintained. As a result, a roughening treatment layer having a fine concavo-convex structure formed by needle-like or plate-like convex portions having a maximum length of 100 nm to 500 nm, comprising copper oxide and cuprous oxide, and having a maximum length of 100 to 500 nm. Can be formed. In the reduction treatment, Cu (I) obtained when qualitative analysis using XPS is performed on the constituent elements of the copper composite compound that forms the fine relief structure by adjusting the reducing agent concentration, solution pH, solution temperature, and the like. The area occupied by the peak of Cu (I) can be appropriately adjusted with respect to the total area of the peak area of Cu and the peak area of Cu (II). Also, for example, by immersing the copper foil with carrier foil in an alkaline solution, fine irregularities mainly composed of copper oxide on both surfaces of the copper foil with carrier foil, that is, the outer surface of the carrier foil and the outer surface of the bulk copper layer, respectively. If the structure is formed and then the reduction treatment is performed only on the roughened layer on the outer surface of the bulk copper layer, the laser light irradiation surface has a Cu (I) peak occupancy of 0%, and the insulating layer constituent material The bonding surface can be a copper foil with carrier foil having a Cu (I) peak occupancy of 50% or more. When the constituent elements of the fine concavo-convex structure formed by the above method are analyzed by XPS, the presence of “—COOH” is detected.

The present application relates to a method for manufacturing a copper foil with a carrier foil, a copper clad laminate, and a printed wiring board.

< Manufacturing method of printed wiring board>
The method for producing a printed wiring board according to the present application is a method for producing a printed wiring board using the copper foil with carrier foil according to the present application , wherein the roughening layer of the carrier foil of the copper foil with carrier foil is used. Laser drilling is performed by irradiating the surface with laser light.

Hereinafter, the “form of the copper clad laminate” and the “form of the printed wiring board manufacturing method ” according to the present application will be described. In the “form of copper-clad laminate”, the “form of copper foil with carrier foil” according to the present application will also be described.

<Mode of manufacturing printed wiring board>
The printed wiring board obtained by the method for manufacturing a printed wiring board according to the present application includes a copper layer formed using the bulk copper layer of the copper foil with carrier foil according to the present application, and the copper according to the present application. It may be manufactured using a tension laminate. In the printed wiring board obtained by the method for manufacturing a printed wiring board according to the present application, the copper layer is preferably provided with a via hole formed by laser drilling. For example, it can be set as the multilayer printed wiring board manufactured by the buildup process as shown in FIGS.

Hereinafter, the form of the manufacturing method of the printed wiring board which concerns on this application is demonstrated, referring FIGS. 5-7 with the printed wiring board obtained by the said manufacturing method . However, the layer configuration and manufacturing method of the printed wiring board according to the present application are not limited to the forms described below, and the copper formed using the bulk copper layer of the copper foil with carrier foil according to the present application. Any form provided with a layer can be included.

Claims (13)

A copper foil with a carrier foil comprising a layer structure of carrier foil / peeling layer / bulk copper layer,
On both surfaces of the copper foil with carrier foil, provided with a roughening treatment layer having a fine concavo-convex structure formed by needle-like or plate-like convex portions having a maximum length of 500 nm or less made of a copper composite compound,
The roughening treatment layer provided on the surface of the carrier foil is used as a laser light absorption layer,
A roughening layer provided on the surface of the bulk copper layer is used as an adhesive layer with an insulating layer constituent material. The total area of Cu (I) peak area and Cu (II) peak area obtained by analyzing the constituent elements of the fine concavo-convex structure by X-ray photoelectron spectroscopy is the same as that of Cu (I). The copper foil with carrier foil according to claim 1, wherein the proportion of the peak area is less than 50% of the roughened layer as the laser light absorbing layer and 50% or more of the roughened layer as the adhesive layer. Foil. The roughening treatment layer as the laser light absorption layer has the fine concavo-convex structure made of a copper composite compound containing copper oxide as a main component, and the roughening treatment layer as the adhesive layer has a cuprous oxide as a main component. The copper foil with a carrier foil according to claim 1, wherein the copper foil has the fine concavo-convex structure made of a copper composite oxide. Using a scanning electron microscope, when the roughened layer is observed at an inclination angle of 45 ° and a magnification of 50000 times or more, a tip that can be separately observed from other convex portions among the convex portions adjacent to each other The length of a part is 250 nm or less, The copper foil with a carrier foil as described in any one of Claims 1-3. The copper foil with a carrier foil according to claim 4, wherein a length of the tip portion of the convex portion is ½ or less with respect to the maximum length of the convex portion. The copper foil with a carrier foil according to any one of claims 1 to 5, wherein a specific surface area measured by adsorbing krypton on the surface of the roughening treatment layer is 0.035 m ² / g or more. The lightness L ^* when the surface of the roughening treatment layer is expressed in an L ^* a ^* b ^* color system is 30 or less. The copper foil with a carrier foil according to any one of claims 1 to 6. . When the surface area of the roughened layer measured by a laser method for a 57570 μm ² two-dimensional region is defined as a three-dimensional surface area (Aμm ² ), and the ratio of the three-dimensional surface area to the area of the two-dimensional region is defined as B, The copper foil with carrier foil according to any one of claims 1 to 7, wherein is 1.1 or more. The copper foil with a carrier foil according to any one of claims 1 to 8, wherein a surface roughness (Rzjis) of the bulk copper layer on the adhesive layer side is 2.0 µm or less. The copper foil with a carrier foil according to any one of claims 1 to 9, wherein a surface of the bulk copper layer on the adhesive layer side is subjected to a silane coupling agent treatment. The copper clad laminate, wherein the adhesive layer side of the bulk copper layer of the copper foil with carrier foil according to any one of claims 1 to 10 is laminated on at least one side of an insulating layer constituent material. . The printed wiring board provided with the copper layer formed using the said bulk copper layer of the copper foil with a carrier foil as described in any one of Claims 1-10. The printed wiring board according to claim 12, wherein the copper layer includes a via hole formed by laser drilling.

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