TWI660658B - Method for manufacturing release foil-attached metal foil, metal foil, laminate, printed wiring board, semiconductor package, electronic device, and printed wiring board - Google Patents

Abstract

The present invention controls the uneven state of the surface of the metal foil and provides "a metal foil capable of physically peeling the resin substrate when the metal foil is bonded to the resin substrate by providing a release layer on the metal foil", and has a low Cost-effectively manufacture a printed wiring board having fine circuits. The present invention relates to a metal foil with a release layer, comprising: a metal foil having a first surface and a second surface, and a root mean square height Sq of the first surface of 0.01 μm or more and 1 μm or less; Two-sided release layer.

Description

   Method for manufacturing release foil-attached metal foil, metal foil, laminate, printed wiring board, semiconductor package, electronic device, and printed wiring board   

The invention relates to a method for manufacturing a metal foil with a release layer, a metal foil, a laminate, a printed wiring board, a semiconductor package, an electronic device, and a printed wiring board.

In the circuit formation method of printed wiring substrates and semiconductor package substrates, the subtraction method is the mainstream. However, due to the further miniaturization of wiring in recent years, M-SAP (Modified Semi-Additive Process) or a semi-additive surface profile using metal foil New methods such as success methods are beginning to prevail.

Among these novel circuit formation methods, as an example of the latter semi-additive method using a surface profile of a metal foil, the following method can be cited. That is, first, the entire surface of the metal foil laminated on the resin substrate is etched, and the surface of the etched substrate on which the surface contour of the metal foil is transferred is opened with a laser or the like. The electrolytic copper plating layer covers the surface of the electroless copper plating with a dry film, removes the dry film of the circuit forming portion by UV exposure and development, performs electrolytic copper plating on the non-electrolytic copper plating surface not covered by the dry film, and dries the dry film. After peeling off, the electroless copper plating layer is etched (rapid etching, rapid etching) with an etching solution containing sulfuric acid, hydrogen peroxide, or the like, thereby forming a fine circuit (Patent Document 1, Patent Document 2).

[Prior technical literature]

[Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2006-196863

[Patent Document 2] Japanese Patent Laid-Open No. 2007-242975

However, in terms of manufacturing printed wiring boards with fine circuits at low cost, there is still room for research on the existing semi-additive method using a surface profile of metal foil.

As a result of diligent research, the present inventors have controlled the uneven state of the surface of the metal foil. In addition, a release layer is provided on the surface of the metal foil on the opposite side to the surface whose unevenness is controlled, so that physical peeling of the resin substrate when the metal foil is bonded to the resin substrate can be achieved. Furthermore, it was found that by using the above-mentioned metal foil, a printed wiring board having a fine circuit can be manufactured at low cost. That is, after the surface side of the metal foil having a release layer is bonded to a resin substrate, a circuit is formed on the surface of the metal foil whose uneven state is controlled. Then, a resin is embedded in the area of the metal foil on which the circuit is formed so as to embed the circuit. Subsequently, the metal foil was peeled from the resin substrate, and the metal foil was removed to expose the above-mentioned circuit. As a result, it was found that a printed wiring board having a fine circuit can be manufactured at a low cost.

One aspect of the present invention completed based on the above findings is a metal foil with a release layer, which includes a first surface and a second surface, and a root mean square height Sq of the first surface is 0.01 μm or more and 1 μm The following metal foil and a release layer provided on the second surface of the metal foil.

In one embodiment of the metal foil with a release layer of the present invention, the root mean square height Sq of the second surface of the metal foil is 0.25 μm or more and 1.6 μm or less.

In another embodiment, the metal foil with a release layer of the present invention has a surface having a ratio (Sq / Rsm) of the root mean square height Sq of the second surface of the metal foil to the average interval Rsm of irregularities of 0.03 or more and 0.40 or less. Bump.

In another embodiment of the metal foil with a mold release layer of this invention, the thickness of the said metal foil is 1 micrometer or more and 105 micrometers or less.

In another embodiment of the metal foil with a mold release layer of this invention, the said metal foil is a copper foil.

In still another embodiment of the metal foil with a release layer according to the present invention, a first member selected from a roughening treatment layer and a heat-resistant layer is provided between the first surface of the metal foil and / or the metal foil and the release layer. One or more of the group consisting of a rust-proof layer, a chromate-treated layer, and a silane coupling-treated layer.

In another embodiment of the metal foil with a release layer of the present invention, the above-mentioned provided on the first surface of the metal foil is selected from the group consisting of a roughened layer, a heat-resistant layer, a rust-proof layer, a chromate-treated layer, and a silane. One or more layers in the group consisting of the coupling treatment layers are provided with a resin layer.

In still another embodiment of the metal foil with a release layer according to the present invention, the resin layer is a resin, a primer, or a semi-cured resin.

In another embodiment of the metal foil with a release layer of the present invention, the release layer includes at least one or two or more of the following compounds selected from the group consisting of an aluminate compound and titanium represented by the following chemical formula: Salt compounds, zirconate compounds, hydrolysates of aluminate compounds, hydrolysates of titanate compounds, hydrolysates of zirconate compounds, condensation products of hydrolysates of aluminate compounds, hydrolysis of titanate compounds In the group consisting of the condensate of the product and the condensate of the hydrolyzate of the zirconate compound, (R ¹ ) _m -M- (R ² ) _n

(In the formula, R ¹ is an alkoxy group or a halogen atom, and R ² is a hydrocarbon group selected from the group consisting of an alkyl group, a cycloalkyl group, and an aryl group, or one or more hydrogen atoms of the above hydrocarbon group are replaced by a halogen atom. Hydrocarbon group, M is any one of Al, Ti, Zr, n is 0, 1, or 2, m is an integer of 1 or more and M or less, and at least one of R ¹ is an alkoxy group; m + n Is the valence of M; the valence of M is 3 in the case of Al and 4) in the case of Ti and Zr.

In another embodiment of the metal foil with a release layer of the present invention, the release layer includes at least one or two or more of the following compounds selected from the group consisting of a silane compound represented by the following chemical formula, and the silane compound In the group consisting of

(In the formula, R ¹ is an alkoxy group or a halogen atom, and R ² is a hydrocarbon group selected from the group consisting of an alkyl group, a cycloalkyl group, and an aryl group, or one or more hydrogen atoms of the above hydrocarbon group are replaced by a halogen atom. R ³ and R ⁴ are each independently a halogen atom, an alkoxy group, one or more of the above-mentioned hydrocarbon group or one or more hydrogen atoms of the above-mentioned hydrocarbon group selected from the group consisting of an alkyl group, a cycloalkyl group, and an aryl group are halogen atoms. Substituted hydrocarbyl).

In another embodiment of the metal foil with a mold release layer of this invention, the said mold release layer is a compound using the compound which has two or less mercapto groups in a molecule | numerator.

In another embodiment of the metal foil with a mold release layer of this invention, the resin layer is provided in the surface of the said mold release layer.

In still another embodiment of the metal foil with a release layer according to the present invention, the resin layer is a resin, a primer, or a semi-cured resin.

Another aspect of the present invention is a metal foil having a first surface and a second surface, and the root mean square height Sq of the first surface is 0.01 μm or more and 1 μm or less.

In one embodiment of the metal foil of the present invention, the root mean square height Sq of the second surface is 0.25 μm or more and 1.6 μm or less.

In another embodiment of the metal foil of the present invention, the ratio (Sq / Rsm) of the root-mean-square height Sq of the second surface of the metal foil to the average interval Rsm of irregularities is 0.03 or more and 0.40 or less.

In another embodiment of the metal foil of this invention, the thickness of the said metal foil is 1 micrometer or more and 105 micrometers or less.

In another embodiment of the metal foil of this invention, the said metal foil is a copper foil.

In still another embodiment of the metal foil of the present invention, the first surface of the metal foil and / or the second surface of the metal foil is provided with a member selected from a roughened layer, a heat-resistant layer, a rust-proof layer, and chromic acid. One or more layers in the group consisting of a salt-treated layer and a silane coupling-treated layer.

In still another embodiment of the metal foil of the present invention, the above-mentioned provided on the first surface of the metal foil is selected from the group consisting of a roughening treatment layer, a heat-resistant layer, a rust prevention layer, a chromate treatment layer, and a silane coupling treatment layer. One or more layers in the composed group are provided with a resin layer.

Still another aspect of the present invention is a laminated body including the metal foil with a release layer of the present invention or the metal foil of the present invention, and a resin substrate provided on the metal foil with the release layer or the metal foil.

In one Embodiment of the laminated body of this invention, the said resin base material is a prepreg, or contains a thermosetting resin.

Another aspect of this invention is a printed wiring board provided with the metal foil with a mold release layer of this invention, or the metal foil of this invention.

Another aspect of the present invention is a semiconductor package including the printed wiring board of the present invention.

Another aspect of the present invention is an electronic device including the printed wiring board of the present invention or the semiconductor package of the present invention.

Another aspect of the present invention is a method for manufacturing a printed wiring board, comprising the steps of: bonding an insulating substrate to the metal foil with a release layer of the present invention or the metal foil of the present invention; Or the metal foil is peeled from the insulating substrate without being etched, and an insulating substrate having the surface profile of the metal foil with a release layer or the metal foil transferred to a peeling surface is obtained; and the surface is transferred to the surface A circuit is formed on the peeling surface side of the contoured insulating substrate.

In one embodiment of the method for manufacturing a printed wiring board according to the present invention, the circuit formed on the peeling surface side of the insulating substrate to which the surface contour is transferred is a plating pattern or a printed pattern.

Another aspect of the present invention is a method for manufacturing a printed wiring board, comprising the steps of: bonding an insulating substrate to the metal foil with a release layer of the present invention or the metal foil of the present invention; Or the metal foil is peeled from the insulating substrate without being etched, and an insulating substrate having the surface profile of the metal foil with a release layer or the metal foil transferred to a peeling surface is obtained; and the surface is transferred to the surface A build-up layer is provided on the peeling surface side of the contoured insulating substrate.

In one embodiment of the method for manufacturing a printed wiring board of the present invention, the resin constituting the build-up layer includes a liquid crystal polymer, a fluororesin, a low dielectric constant polyfluorene imide, a polyphenylene ether, a cycloolefin polymer, or polytetramethylene. Fluoroethylene.

Another aspect of the present invention is a method for manufacturing a printed wiring board, comprising the steps of: in the metal foil with a release layer of the present invention or the metal foil of the present invention, from the release layer side or the second surface of the metal foil An insulating substrate 1 is bonded to the side; a circuit is formed on the first surface side of the metal foil with the release layer or the metal foil laminated with the insulating substrate 1; the circuit is buried in the circuit by covering the circuit with the insulating substrate 2 Insulating substrate 2; peeling off the insulating substrate 1 from the release-layer-attached metal foil or the metal foil to expose the release-layer-attached metal foil or the metal foil; and exposing the exposed release-layer-attached metal foil or the metal Remove the foil.

Another aspect of the present invention is a method for manufacturing a printed wiring board, comprising the steps of: in the metal foil with a release layer of the present invention or the metal foil of the present invention, from the release layer side or the second surface of the metal foil Laminate the insulating substrate 1 on the side; laminate the dry film on the first side of the metal foil with the release layer of the insulating substrate 1 or the first surface of the metal foil; pattern the dry film to form a circuit; peel the dry film The circuit is exposed; the circuit is buried in the insulating substrate 2 by covering the exposed circuit with the insulating substrate 2; the insulating substrate 1 is peeled from the metal foil with a release layer or the metal foil to expose the adhesion The mold layer metal foil or the metal foil; and removing the exposed metal foil with the release layer or the metal foil.

By controlling the unevenness of the surface of the metal foil, and by providing "a metal foil that can physically peel off the resin substrate when the metal foil is bonded to the resin substrate by providing a release layer on the metal foil", it is possible to reduce the cost. Manufacture of printed wiring boards with fine circuits.

1A to 1C are schematic diagrams of a cross section of a wiring board in a specific example of a method for manufacturing a printed wiring board using a copper foil with a release layer according to the present invention, in steps from circuit plating and resist removal.

FIGS. 2D to F are steps in a specific example of a method for manufacturing a printed wiring board using a copper foil with a release layer according to the present invention, from the step of laminating a resin and a second copper foil with a release layer to a laser opening; Schematic diagram of cross section of wiring board.

3G to I are schematic diagrams of a cross-section of a wiring board in a specific example of a method for manufacturing a printed wiring board using a copper foil with a release layer according to the present invention, in a step from filling a hole to peeling of a first release layer.

4J to K are schematic diagrams of cross-sections of a wiring board in a specific example of a method for manufacturing a printed wiring board using the release layer copper foil with the present invention, from rapid etching to formation of bumps and copper pillars.

FIG. 5 is a schematic diagram showing a semi-additive method using a copper foil profile.

(Metal foil)

The metal foil of this invention is a metal foil which has a 1st surface and a 2nd surface, and the root-mean-square height Sq of the surface of the said 1st surface side is 0.01 micrometer or more and 1 micrometer or less. By controlling the root mean square height Sq of the first surface in this way, the uneven state of the surface of the metal foil is controlled. In addition, by using the metal foil described below, a printed wiring board having a fine circuit can be manufactured at low cost. That is, a mold release layer is provided on the surface of the metal foil on the opposite side to the surface whose unevenness is controlled, so that the resin substrate can be physically peeled when the metal foil is bonded to the resin substrate. Next, a circuit is formed on the surface of the metal foil whose surface unevenness is controlled after the surface side of the metal foil having a release layer is bonded to a resin substrate. Then, a resin is layered on the metal foil surface area on which the circuit is formed so as to embed the circuit. Subsequently, the metal foil is peeled from the resin base material, and the metal foil is removed to expose the above-mentioned circuit, whereby a printed wiring board can be manufactured. When a printed wiring board is manufactured by the above method, a circuit can be formed without providing an electroless plating layer on a resin substrate by electroless plating. Therefore, the manufacturing cost of a printed wiring board can be reduced. Furthermore, the circuit is protected by burying the circuit in a resin. Therefore, when the metal foil is removed by etching or the like, the circuit is not easily etched by the etching or the like. Therefore, a fine circuit can be formed.

In addition, when a surface treatment layer such as a roughening treatment layer, a heat-resistant layer, a rust prevention layer, a chromate treatment layer, a silane coupling treatment layer, and a release layer is provided on the surface of a metal foil, the so-called "first The "surface" and the "second surface of the metal foil" refer to the surface (the surface of the outermost layer) after the surface treatment layer is provided. In the present specification, the "first side" is also referred to as "one side", and the "second side" is also referred to as "the other side".

Since the root-mean-square height Sq of the first surface of the metal foil of the present invention is 0.01 μm or more, the metal foil has good adhesion to the above-mentioned circuit or a resin embedded in the circuit. As a result, peeling or peeling of the circuit or the resin embedded in the circuit from the metal foil is reduced. In addition, the metal foil of the present invention has good circuit formability because the root mean square height Sq of the first surface is 1 μm or less.

When the root-mean-square height Sq of the first surface of the metal foil is less than 0.01 μm, the unevenness of the unevenness of the surface of the metal foil may be too small. Therefore, the adhesion of the metal foil to the circuit or the resin in which the circuit is embedded may be deteriorated. As a result, the circuit or the resin embedded in the circuit may be peeled off or peeled off from the metal foil. When the root-mean-square height Sq of the first surface of the metal foil exceeds 1 μm, the unevenness of the surface of the metal foil may be excessively large. As a result, in a portion where the convex portion on the surface of the metal foil is large, it is necessary to perform etching or the like for a longer time when removing the metal foil. As a result, there is a case where the erosion of the circuit due to etching or the like increases, and the wiring formability is deteriorated. The root-mean-square height Sq of the first surface of the metal foil is preferably 0.95 μm or less, preferably 0.93 μm or less, preferably 0.90 μm or less, preferably 0.85 μm or less, more preferably 0.80 μm or less, and more preferably 0.75 μm or less, preferably 0.70 μm or less, preferably 0.68 μm or less, preferably 0.67 μm or less, preferably 0.65 μm or less, preferably 0.60 μm or less, preferably 0.55 μm or less, preferably 0.50 μm or less, preferably 0.45 μm or less, preferably 0.40 μm or less, preferably 0.35 μm or less, preferably 0.32 μm or less, preferably 0.30 μm or less, preferably 0.25 μm or less, preferably 0.24 μm Hereinafter, it is preferably 0.22 μm or less, preferably 0.20 μm or less, preferably 0.19 μm or less, more preferably 0.18 μm or less, more preferably 0.17 μm or less, and even more preferably 0.15 μm or less. The root-mean-square height Sq of the first surface of the metal foil is preferably 0.015 μm or more, preferably 0.02 μm or more, preferably 0.025 μm or more, preferably 0.03 μm or more, preferably 0.035 μm or more, and more preferably 0.04 μm or more, preferably 0.045 μm or more, and more preferably 0.05 μm or more.

The root mean square height Sq of the second surface of the metal foil is preferably 0.25 μm or more and 1.6 μm or less. Since the root-mean-square height Sq of the second surface of the metal foil is 0.25 to 1.6 μm, the peelability after the metal foil is bonded to the resin substrate can be maintained, and multilayer components such as circuits, resins, or buildups are transferred due to transfer. The concave-convex shape on the surface of the resin substrate after peeling the metal foil follows the surface of the resin substrate without voids (or extremely small voids), and the laminated components such as circuits, resins, or buildups are provided on the surface of the resin substrate with good adhesion. .

If the root-mean-square height Sq of the second surface of the metal foil is less than 0.25 μm, there is a concern that the surface roughness of the resin substrate obtained by bonding the metal foil to the resin substrate and peeling off the metal foil may cause a problem. If it is small, the adhesiveness with different resins becomes insufficient, and if it exceeds 1.6 μm, there is a concern that the peelability when the metal foil is peeled off after the metal foil is bonded to the resin substrate may be deteriorated. In addition, the uneven shape on the surface of the resin substrate after the metal foil is peeled off is too deep, and the laminated component such as a circuit, a resin, or a buildup does not follow the above uneven shape. The root-mean-square height Sq is preferably 0.30 to 1.4 μm, more preferably 0.4 to 1.0 μm, and even more preferably 0.4 to 0.96 μm.

The ratio (Sq / Rsm) of the root mean square height Sq of the second surface of the metal foil to the average interval Rsm of the unevenness is preferably 0.03 or more and 0.40 or less. Since the ratio (Sq / Rsm) of the root-mean-square height Sq of the second surface of the metal foil to the average interval Rsm of the unevenness is 0.03 or more and 0.40 or less, the peelability after bonding the metal foil to the resin substrate is good. And the laminated components such as circuits, resins, or buildups follow the uneven shape of the surface of the resin substrate after the metal foil is peeled off, and follow without voids (or very small voids), and the circuit, resin or Laminated members such as layers are provided on the surface of the resin substrate.

If the ratio (Sq / Rsm) of the root-mean-square height Sq of the second surface of the metal foil to the average interval Rsm of the unevenness is less than 0.03, a problem arises that the metal foil is peeled off after the metal foil is bonded to the resin substrate to obtain The unevenness of the surface of the resin substrate is small, and the adhesion between the resin substrate and the laminated components such as the circuit, resin, or buildup becomes insufficient. If it exceeds 0.40, the following problem may occur: the metal foil and the resin substrate are stuck. The peelability when the metal foil is peeled after the bonding is deteriorated, and the uneven shape on the surface of the resin substrate after the metal foil is peeled off is too deep, and the laminated member such as a circuit, resin, or buildup does not follow the uneven shape. The ratio (Sq / Rsm) of the root mean square height Sq of the second surface of the metal foil to the average interval Rsm of the unevenness is preferably 0.05 or more, and more preferably 0.10 or more. The ratio (Sq / Rsm) of the root mean square height Sq of the second surface of the metal foil to the average interval Rsm of irregularities is preferably 0.25 or less, more preferably 0.24 or less, and even more preferably 0.20 or less.

(With release layer metal foil)

The metal foil with a release layer of the present invention includes a metal foil and a release layer, the metal foil has a first surface and a second surface, and a root mean square height Sq of the first surface is 0.01 μm or more and 1 μm or less. The mold layer is a release layer provided on the second surface side of the metal foil, and the resin substrate can be peeled from the release layer side when a resin substrate is bonded to the metal foil. By controlling the root mean square height Sq of the first surface in this way, the uneven state of the surface of the metal foil is controlled. In addition, a release layer is provided on the surface of the metal foil on the opposite side to the surface whose unevenness is controlled, so that the resin substrate can be physically peeled when the metal foil is bonded to the resin substrate. In addition, by using the metal foil described below, a printed wiring board having a fine circuit can be manufactured at low cost. That is, after the surface side of the metal foil having a release layer is bonded to a resin substrate, a circuit is formed on the surface of the metal foil whose surface unevenness state is controlled. Then, a resin is layered on the metal foil surface area on which the circuit is formed so as to embed the circuit. Subsequently, the metal foil is peeled from the resin base material, and the metal foil is removed to expose the above-mentioned circuit, whereby a printed wiring board can be manufactured. When a printed wiring board is manufactured by the above method, a circuit can be formed without providing an electroless plating layer on a resin substrate by electroless plating. Therefore, the manufacturing cost of a printed wiring board can be reduced. Furthermore, the circuit is protected by burying the circuit in a resin. Therefore, when the metal foil is removed by etching or the like, the circuit is not easily etched by the etching or the like. Therefore, a fine circuit can be formed.

Since the metal foil with the release layer metal foil has a root-mean-square height Sq of the first surface that is the side on which the release layer is not formed is 0.01 μm or more, the adhesion to the above-mentioned circuit or the resin embedded in the circuit is excellent. good. As a result, the occurrence of peeling or peeling of the circuit or the resin embedded in the circuit from the metal foil is reduced. In addition, since the metal foil has a root-mean-square height Sq of the first surface that is the side on which the release layer is not formed is 1 μm or less, the circuit formability is good.

If the first surface root-mean-square height Sq of the surface of the metal foil on which the release layer is not formed is less than 0.01 μm, the unevenness of the surface of the metal foil may be too small. When the unevenness of the surface of the metal foil is too small, high convex portions or deep concave portions that contribute to the adhesion between the metal foil and the circuit or the adhesion between the metal foil and the circuit or the resin in which the circuit is embedded may decrease. Therefore, the adhesion of the metal foil to the above-mentioned circuit or the resin in which the circuit is embedded may be deteriorated. As a result, the circuit or the resin embedded in the circuit may be peeled off or peeled off from the metal foil. In addition, if the first surface root-mean-square height Sq on the side of the metal foil on which the release layer is not formed exceeds 1 μm, the unevenness of the surface of the metal foil may be excessively large. As a result, in a part where the convex portion on the surface of the metal foil is large, it is necessary to perform etching for a longer time when removing the metal foil. As a result, there is a case where the erosion of the circuit due to etching or the like increases, and the wiring formability is deteriorated. The root-mean-square height Sq of the surface on the side where the mold release layer is not formed, that is, the first surface, is preferably 0.95 μm or less, preferably 0.93 μm or less, preferably 0.90 μm or less, preferably 0.85 μm or less, and more preferably 0.80 μm or less, preferably 0.75 μm or less, preferably 0.70 μm or less, preferably 0.68 μm or less, preferably 0.67 μm or less, preferably 0.65 μm or less, preferably 0.60 μm or less, preferably 0.55 μm or less, preferably 0.50 μm or less, preferably 0.45 μm or less, preferably 0.40 μm or less, preferably 0.35 μm or less, preferably 0.32 μm or less, preferably 0.30 μm or less, preferably 0.25 μm or less, preferably 0.24 μm or less, preferably 0.22 μm or less, preferably 0.20 μm or less, preferably 0.19 μm or less, preferably 0.18 μm or less, preferably 0.17 μm or less, more preferably 0.15 μm the following. The root-mean-square height Sq of the surface on the side where the mold release layer is not formed, that is, the first surface, is preferably 0.015 μm or more, preferably 0.02 μm or more, preferably 0.025 μm or more, preferably 0.03 μm or more, and more preferably It is 0.035 μm or more, preferably 0.04 μm or more, preferably 0.045 μm or more, and more preferably 0.05 μm or more.

The root mean square height Sq of the second surface of the metal foil on which the release layer is formed is preferably 0.25 μm or more and 1.6 μm or less. Since the root-mean-square height Sq of the second surface of the metal foil on which the release layer is formed is 0.25 to 1.6 μm, the peelability after bonding the metal foil to the resin substrate is maintained, and the circuit is maintained. Laminated components such as resin, buildup, etc. follow the surface of the resin substrate without voids (or very small voids) due to the uneven shape on the surface of the resin substrate after the metal foil is peeled off. The circuit, resin or Laminated members such as build-up are provided on the surface of the resin substrate.

If the root-mean-square height Sq of the second surface of the metal foil on which the release layer is formed is less than 0.25 μm, there is a concern that the metal foil and the resin substrate are peeled after being bonded together. The unevenness of the surface of the resin substrate obtained by the metal foil is small, and the adhesiveness with different resins becomes insufficient. If it exceeds 1.6 μm, there is a concern that the metal foil and the resin substrate are stuck together. The peelability when the metal foil is peeled after the bonding is deteriorated, and the uneven shape on the surface of the resin substrate after the metal foil is peeled off is too deep, and the laminated member such as a circuit, resin, or buildup does not follow the uneven shape. The root-mean-square height Sq is preferably 0.30 to 1.4 μm, more preferably 0.4 to 1.0 μm, and even more preferably 0.4 to 0.96 μm.

The ratio (Sq / Rsm) of the root mean square height Sq of the second surface of the metal foil on which the release layer is formed to the average interval Rsm of the unevenness on the second surface (Sq / Rsm) is preferably 0.03 or more and 0.40 or less. Since the ratio (Sq / Rsm) of the root mean square height Sq of the second surface of the metal foil on the side on which the release layer is formed to the average interval Rsm of the unevenness is 0.03 or more and 0.40 or less, the metal foil can be maintained. The peelability after bonding to the resin substrate is good, and laminated components such as circuits, resins, or buildups follow the uneven shape of the resin substrate surface after the metal foil is peeled off, and follow without voids (or very small voids). Laminated components such as circuits, resins, and buildups are provided on the surface of a resin substrate with good adhesion.

If the ratio (Sq / Rsm) of the root mean square height Sq of the second surface of the metal foil on which the release layer is formed, that is, the second surface, to the average interval Rsm of irregularities (Sq / Rsm) is less than 0.03, the following problem arises: The unevenness of the surface of the resin substrate obtained by peeling the metal foil after bonding the resin substrate is small, and the adhesion between the resin substrate and the laminated components such as the circuit, resin, or buildup becomes insufficient. If it exceeds 0.40, it will cause The following problems: the peelability when the metal foil is peeled off after the metal foil is bonded to the resin substrate, and the uneven shape on the surface of the resin substrate after the metal foil is peeled is too deep, and the laminated components such as circuits, resins, or buildups are not followed The above uneven shape. The ratio (Sq / Rsm) of the root mean square height Sq of the second surface of the metal foil on which the release layer is formed to the average interval Rsm of the unevenness of the second surface (Sq / Rsm) is preferably 0.05 or more, and more preferably 0.10 or more. The ratio (Sq / Rsm) of the root-mean-square height Sq of the second surface of the metal foil on which the release layer is formed to the average interval Rsm of the unevenness of the second surface is preferably 0.25 or less, more preferably 0.24 or less, and more preferably It is 0.20 or less.

The metal foil (also called green foil) is not particularly limited, and copper foil, aluminum foil, nickel foil, copper alloy foil, nickel alloy foil, aluminum alloy foil, stainless steel foil, iron foil, iron alloy foil, zinc foil, and zinc alloy can be used. Foil, cobalt foil, cobalt alloy foil, etc. In addition, a well-known metal foil can be used as the metal foil.

The thickness of the metal foil (green foil) is not particularly limited. For example, it can be 1 to 105 μm, or 3 to 105 μm, or 5 to 105 μm. In addition, in terms of easy peeling from the resin substrate, the thickness of the metal foil is preferably 9 to 70 μm, more preferably 12 to 35 μm, and still more preferably 18 to 35 μm. In addition, from the viewpoint that the metal foil (green foil) can be easily removed by etching or the like, the thickness of the metal foil is preferably thin. For example, the thickness of the metal foil is preferably 105 μm or less, preferably 70 μm or less, preferably 35 μm or less, more preferably 18 μm or less, and even more preferably 12 μm or less. In addition, from the viewpoint of facilitating the processing of metal foil (green foil), it is preferable that the thickness of the metal foil is thick. For example, the thickness of the metal foil is preferably 1 μm or more, and more preferably 3 μm or more.

Hereinafter, a copper foil as an example of a metal foil (green foil) will be described. The manufacturing method of a metal foil (green foil) is not specifically limited, For example, an electrolytic copper foil can be manufactured using the following electrolytic conditions. The following method can also be applied to metal foils other than copper foil (electrolytic metal foil and rolled metal foil).

<Manufacturing method of electrolytic copper foil>

The electrolytic copper foil of the present invention is produced by electrolyzing copper from a copper sulfate plating bath onto a titanium or stainless steel drum. The electrolytic conditions are not particularly limited, and for example, an electrolytic copper foil can be produced under the following conditions.

Electrolyte composition:

Cu: 30 ~ 190g / L

H ₂ SO ₄ : 100 ~ 400g / L

Chloride ion (Cl ^-): 60 ~ 200 ppm Quality

Animal glue: 1 ~ 10ppm

(Use bis (3-sulfopropyl) disulfide (SPS) as needed: 10 ~ 100ppm)

Electrolyte temperature: 25 ~ 80 ℃

Electrolysis time: 10 ~ 300 seconds (adjusted according to the copper thickness and current density)

Current density: 50 ~ 150A / dm ²

Linear speed of electrolyte: 1.5 ~ 5m / sec

In addition, in this specification, liquids such as an electrolytic solution, a plating solution, a silane coupling treatment liquid, a liquid used for forming a mold release layer, or the rest of the treatment liquid used for surface treatment are water unless otherwise specified. .

The root mean square height Sq of the drum surface of the electrolytic drum used at this time is 1.0 μm or less, and preferably 0.70 μm or less. Regarding the electrolytic drum having the above-mentioned root-mean-square height Sq on the surface, first the surface of the titanium or stainless steel drum is polished by using a polishing belt numbered from P150 to P2500. At this time, the grinding is performed while the grinding belt is wound around a specified width in the width direction of the drum, and the grinding belt is moved in the width direction of the drum at a specified speed, while the drum is rotated to perform grinding. The rotation speed of the drum surface during the above-mentioned polishing is set to 120 to 195 m / min. The rotation speed of the drum surface is expressed by the following mathematical formula.

Rotation speed on the surface of the drum (m / min) = revolutions per minute of the electrolytic drum (times / minute) × circumference of each revolution of the electrolytic drum (m / times)

Circumference length (m / times) of each rotation of electrolytic drum = diameter (m) of electrolytic drum × pi / 1 (times)

In addition, the polishing time is the product of the time that passes one point (position in the width direction) on the surface of the drum in one stroke of the polishing belt and the number of strokes. In addition, the time to pass one point on the surface of the drum in the above-mentioned one stroke is a value obtained by dividing the width of the polishing belt by the moving speed of the polishing belt in the width direction of the drum. In addition, the so-called single stroke of the polishing tape means that the surface of the drum in the circumferential direction is performed once from one end to the other end of the shaft (width) direction (the width direction of the electrolytic copper foil) of the drum using the polishing tape. Grinding. That is, the polishing time is expressed by the following mathematical formula.

Grinding time (minutes) = width of the grinding belt (cm / time) per stroke / moving speed of the grinding belt (cm / minute) × number of strokes (times)

In the present invention, the grinding time is 3 to 25 minutes. In addition, in the present invention, when the surface of the drum is wetted with water during grinding, the grinding time is set to 6 to 25 minutes. As an example of the calculation of the polishing time, for example, when the polishing belt width is 10 cm and the moving speed is 20 cm / minute, the polishing time per one stroke of one point on the surface of the drum is 0.5 minute. The polishing time is calculated by multiplying the above time by the total number of strokes (for example, 0.5 minutes × 10 strokes = 5 minutes). By increasing the number of grinding belts, and / or increasing the rotation speed of the drum surface, and / or extending the grinding time, and / or wetting the drum surface with water during grinding, the uniformity of the drum surface can be reduced. Square root height Sq. In addition, by reducing the number of polishing belts, and / or reducing the rotation speed of the drum surface, and / or shortening the grinding time, and / or drying the drum surface during grinding, the uniformity of the drum surface can be increased. Square root height Sq. In addition, the root-mean-square height Sq can be reduced by extending the polishing time. Furthermore, the root-mean-square height Sq can be increased by shortening the polishing time. In addition, the number of the said polishing tape means the particle size of the polishing material used for a polishing tape. The particle size of the above-mentioned abrasive material is based on FEPA (Federation of European Producers of Abrasives) -standard 43-1: 2006, 43-2: 2006.

Moreover, the root mean square height Sq can be reduced by wetting the surface of the drum with water during grinding. Moreover, the root-mean-square height Sq can be increased by drying the surface of the drum during grinding.

The root mean square height Sq of the surface of the electrolytic drum can be measured as follows.

‧ Swell the resin film by immersing the resin film (polyvinyl chloride) in a solvent (acetone).

‧ The above swollen resin film was brought into contact with the surface of the electrolytic drum, and the resin film was peeled off after acetone was volatilized from the resin film, and a replica of the surface of the electrolytic drum was collected.

• The above replica was measured with a laser microscope, and the root mean square height Sq was measured.

Then, the value of the root-mean-square height Sq of the obtained replica is set to the root-mean-square height Sq of the surface of the electrolytic drum.

In addition, the ratios (Sq / Rsm) of the root mean square heights Sq, Sq and the average interval Rsm of irregularities can be adjusted by the above-mentioned electrolytic conditions. When the electrolysis time (copper thickness) and / or the current density are increased within the above range, Sq and Sq / Rsm increase. On the other hand, if the chloride ion concentration, animal gum concentration, SPS concentration, and / or electrolyte linear velocity are increased within the above range, Sq and Sq / Rsm tend to decrease. These electrolytic conditions need only be adjusted in accordance with the required degree of peelability and the required adhesion to the laminated member.

Furthermore, the first surface and / or the second surface of the metal foil may be mechanically polished, such as polishing, or chemically polished, such as etching, to adjust the Sq (the polishing referred to herein also includes increasing the degree of unevenness on the surface).

<Manufacturing method of rolled copper foil>

The metal foil (green foil) may be a rolled copper foil (rolled metal foil). The above-mentioned rolled copper foil (rolled metal foil) can release the unformed metal foil by controlling the oil film equivalent at the time of the final cold rolling, the Sq of the calender roll at the final cold rolling, and the process degree of the final cold rolling. The root-mean-square height Sq of the first side surface of the layer on the predetermined side and / or the second side surface of the predetermined side on which the release layer is formed is 1.6 μm or less, 1.0 μm or less, 0.70 μm or less, and / Or 0.01 μm or more and 0.25 μm or more. By increasing the oil film equivalent at the time of the final cold rolling, and / or increasing the value of the Sq of the calender roll of the final cold rolling, and / or decreasing the degree of processing of the final cold rolling, the unformed release of the metal foil can be increased. The value of the root-mean-square height Sq of the surface on the predetermined side of the layer, that is, the first surface, and / or the surface on the predetermined side, on which the release layer is formed, is the second surface. By reducing the oil film equivalent at the time of final cold rolling, and / or reducing the value of Sq of the final cold rolling calender roll, and / or increasing the processing degree of the final cold rolling, it is possible to reduce the unmolded release of the metal foil. The value of the root-mean-square height Sq of the surface on the predetermined side of the layer, that is, the first surface, and / or the surface on the predetermined side, on which the release layer is formed, is the second surface.

In addition, after the final cold rolling, a machine such as polishing and polishing may be performed on the first side of the metal foil on which a predetermined side of the release layer is not formed, and / or the second side of the predetermined side on which the release layer is formed. The above-mentioned Sq is adjusted by chemical polishing such as polishing or etching (the polishing referred to herein also includes increasing the degree of unevenness of the surface).

Next, the mold release layer which can be used for this invention is demonstrated.

(1) Silane compounds

By forming the release layer, when the metal foil and the resin substrate are bonded, the adhesiveness is moderately reduced, and the peel strength can be adjusted to the above range. The release layer includes at least one kind or two or more kinds. A compound selected from the group consisting of a silane compound represented by the following formula, a hydrolysate of a silane compound, and a condensate of the hydrolysate (hereinafter, simply referred to as a silane compound).

formula:

(In the formula, R ¹ is an alkoxy group or a halogen atom, and R ² is a hydrocarbon group selected from the group consisting of an alkyl group, a cycloalkyl group, and an aryl group, or one or more hydrogen atoms of the hydrocarbon group are replaced by a halogen atom. A hydrocarbon group, R ³ and R ⁴ are each independently a halogen atom, an alkoxy group, a hydrocarbon group selected from the group consisting of an alkyl group, a cycloalkyl group, and an aryl group, or one or more hydrogen atoms of the hydrocarbon group are replaced by a halogen atom Hydrocarbon group).

The silane compound must have at least one alkoxy group. When an alkoxy group is absent and only a hydrocarbon group selected from the group consisting of an alkyl group, a cycloalkyl group, and an aryl group, or a substituent composed of any of these hydrocarbon groups in which one or more hydrogen atoms are replaced by a halogen atom, There is a tendency that the adhesion between the resin substrate and the metal foil is excessively reduced. The silane compound must have at least one hydrocarbon group selected from the group consisting of an alkyl group, a cycloalkyl group, and an aryl group, or any one of these hydrocarbon groups in which one or more hydrogen atoms are replaced by a halogen atom. The reason is that when the above-mentioned hydrocarbon group is not present, the adhesion between the resin substrate and the metal foil tends to increase. The alkoxy group also includes an alkoxy group in which one or more hydrogen atoms are replaced with a halogen atom.

In terms of adjusting the peel strength of the resin substrate and the metal foil to the above range, the silane compound preferably has three alkoxy groups and one of the above-mentioned hydrocarbon groups (including a hydrocarbon group in which one or more hydrogen atoms are replaced by halogen atoms). When the above formula is used, both R ³ and R ⁴ are alkoxy groups.

The alkoxy group is not limited, and examples thereof include a methoxy group, an ethoxy group, an n- or isopropoxy group, an n-, iso- or third butoxy group, an n-, iso- or neopentyloxy group, an n-hexyloxy group, and cyclohexyl group. Straight-chain, branched, or cyclic carbons such as oxy, n-heptyloxy, and n-octyloxy have 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms, and more preferably 1 to 5 carbon atoms Alkoxy.

Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

The alkyl group is not limited, and examples include methyl, ethyl, n- or iso-propyl, n-, iso- or third butyl, n-, iso- or neopentyl, n-hexyl, n-octyl, and n-decyl. The chain or branched chain has 1 to 20 carbons, preferably 1 to 10 carbons, and more preferably 1 to 5 carbons.

The cycloalkyl group is not limited, and examples thereof include cycloalkanes having 3 to 10 carbon atoms such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl, and preferably 5 to 7 carbons. base.

Examples of the aryl group include a phenyl group, an alkyl-substituted phenyl group (example: tolyl group, xylyl group), 1- or 2-naphthyl group, and anthracenyl group having 6 to 20 carbon atoms, preferably 6 to 20 14 aryl.

One or more hydrogen atoms of these hydrocarbon groups may be substituted with a halogen atom, and for example, they may be substituted with a fluorine atom, a chlorine atom, or a bromine atom.

As an example of a preferable silane compound, methyl trimethoxysilane, ethyltrimethoxysilane, n- or isopropyltrimethoxysilane, n-, iso- or tributyltrimethoxysilane, n- , Isoor neopentyltrimethoxysilane, hexyltrimethoxysilane, octyltrimethoxysilane, decyltrimethoxysilane, phenyltrimethoxysilane; alkyl substituted phenyltrimethoxysilane ( E.g. p- (meth) phenyltrimethoxysilane), methyltriethoxysilane, ethyltriethoxysilane, n- or isopropyltriethoxysilane, n-, iso- or tributyltrisilane Ethoxysilane, pentyltriethoxysilane, hexyltriethoxysilane, octyltriethoxysilane, decyltriethoxysilane, phenyltriethoxysilane, alkyl-substituted benzene Triethoxysilane (e.g. p- (meth) phenyltriethoxysilane), (3,3,3-trifluoropropyl) trimethoxysilane, and tridecyloctyltriethoxysilane , Methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, phenyltrichlorosilane, trimethylfluorosilane, dimethyldibromosilane , Dibromo diphenyl Silane, hydrolysis products of these compounds, hydrolysates and condensates of these compounds, and the like. Among these compounds, from the viewpoint of easy availability, propyltrimethoxysilane, methyltriethoxysilane, hexyltrimethoxysilane, phenyltriethoxysilane, and decyltrimethoxysilane are preferred. .

In the step of forming the release layer, the silane compound can be used in the form of an aqueous solution. To increase the solubility in water, an alcohol such as methanol or ethanol may be added. The addition of alcohol is particularly effective when a highly hydrophobic silane compound is used. The aqueous solution of the silane compound promotes the hydrolysis of the alkoxy group by stirring. When the stirring time is long, the condensation of the hydrolysate is promoted. In general, when a silane compound that undergoes hydrolysis and condensation after a sufficient stirring time is used, the peel strength of the resin substrate and the metal foil tends to decrease. Therefore, the peeling strength can be adjusted by adjusting the stirring time. The stirring time after dissolving the silane compound in water is not limited. For example, the stirring time can be 1 to 100 hours, and typically 1 to 30 hours. Of course, there is also a method of using a silane compound without stirring.

When the concentration of the silane compound in the aqueous solution of the silane compound is high, the peel strength of the metal foil and the plate-shaped carrier tends to decrease, and the peel strength can be adjusted by adjusting the concentration of the silane compound. The concentration of the silane compound in the aqueous solution is not limited, but can be set to 0.01 to 10.0 vol%, typically 0.1 to 5.0 vol%.

The pH of the aqueous solution of the silane compound is not particularly limited, and it can be used on either the acidic side or the alkaline side. For example, it can be used at a pH in the range of 3.0 to 10.0. From the viewpoint of not requiring special pH adjustment, it is preferably set to a pH in the range of 5.0 to 9.0 near neutrality, and more preferably set to a pH in the range of 7.0 to 9.0.

(2) Compounds having two or less mercapto groups in the molecule

The release layer is composed of a compound having two or more mercapto groups in the molecule. By bonding the resin substrate and the metal foil through the release layer, the adhesiveness is also reduced moderately, and the peel strength can be adjusted.

However, when a compound having three or more thiol groups in the molecule or a salt of the compound is bonded between the resin substrate and the metal foil, it is not suitable for the purpose of reducing the peel strength. The reason is that if there is an excess of sulfhydryl groups in the molecule, sulfide bonds, disulfide bonds, or polysulfide bonds may be excessively generated due to the chemical reaction between the thiol groups, or the thiol group and the plate-shaped support, or the thiol group and the metal foil. The sulfide bond forms a strong three-dimensional cross-linked structure between the resin substrate and the metal foil, thereby increasing the peel strength. Such an example is disclosed in Japanese Patent Laid-Open No. 2000-196207.

Examples of the compound having two or less mercapto groups in the molecule include a thiol, a dithiol, a thiocarboxylic acid or a salt thereof, a dithiocarboxylic acid or a salt thereof, a thiosulfonic acid or a salt thereof, and As the thiosulfonic acid or a salt thereof, at least one compound selected from these compounds can be used.

The thiol has a mercapto group in the molecule, and is represented by R-SH, for example. Here, R represents an aliphatic or aromatic hydrocarbon group or heterocyclic group which may contain a hydroxyl group or an amine group.

Dithiol has two mercapto groups in the molecule, and is represented by R (SH) ₂ , for example. R represents an aliphatic or aromatic hydrocarbon or heterocyclic group which may contain a hydroxyl group or an amine group. The two mercapto groups may be respectively bonded to the same carbon, or may be bonded to different carbons or nitrogen.

A thiocarboxylic acid is a compound in which a hydroxy group of an organic carboxylic acid is replaced with a mercapto group, and is represented by R-CO-SH, for example. R represents an aliphatic or aromatic hydrocarbon or heterocyclic group which may contain a hydroxyl group or an amine group. The thiocarboxylic acid can also be used in the form of a salt. In addition, a compound having two thiocarboxylic acid groups can also be used.

A dithiocarboxylic acid is a compound in which two oxygen atoms in a carboxyl group of an organic carboxylic acid are replaced with a sulfur atom, and is represented by R- (CS) -SH, for example. R represents an aliphatic or aromatic hydrocarbon or heterocyclic group which may contain a hydroxyl group or an amine group. The dithiocarboxylic acid can also be used in the form of a salt. In addition, a compound having two dithiocarboxylic acid groups can also be used.

Thiosulfonic acid is a compound in which a hydroxy group of an organic sulfonic acid is replaced with a mercapto group, and is represented by R (SO ₂ ) -SH, for example. R represents an aliphatic or aromatic hydrocarbon or heterocyclic group which may contain a hydroxyl group or an amine group. The thiosulfonic acid can also be used in the form of a salt.

Dithiosulfonic acid is a compound in which two hydroxyl groups of an organic disulfonic acid are respectively replaced with a mercapto group, and is represented by R-((SO ₂ ) -SH) _{2, for} example. R represents an aliphatic or aromatic hydrocarbon or heterocyclic group which may contain a hydroxyl group or an amine group. Moreover, two thiosulfonic acid groups may be respectively bonded to the same carbon, or may be bonded to mutually different carbons. The dithiosulfonic acid can also be used in the form of a salt.

Here, examples of the aliphatic hydrocarbon group suitable as R include an alkyl group and a cycloalkyl group, and these hydrocarbon groups may contain either or both of a hydroxyl group and an amine group.

The alkyl group is not limited, and examples thereof include methyl, ethyl, n- or iso-propyl, n-, iso- or third butyl, n-, iso-or neopentyl, n-hexyl, n-octyl, and n-decyl. The linear or branched chain is an alkyl group having 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms, and more preferably 1 to 5 carbon atoms.

In addition, the cycloalkyl group is not limited, and examples include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, and the like having 3 to 10 carbon atoms, and preferably 5 to 7 carbon atoms. Cycloalkyl.

Examples of the aromatic hydrocarbon group suitable for R include a phenyl group, an alkyl-substituted phenyl group (for example, tolyl group, xylyl group), 1- or 2-naphthyl group, and anthracenyl group. 20. The aryl group is preferably 6 to 14. These hydrocarbon groups may also contain any one or both of a hydroxyl group and an amine group.

In addition, examples of the heterocyclic group suitable as R include imidazole, triazole, tetrazole, benzimidazole, benzotriazole, thiazole, and benzothiazole, and they may contain either one or both of a hydroxyl group and an amino group. Each.

Preferred examples of the compound having two or less mercapto groups in the molecule include 3-mercapto-1,2 propylene glycol, 2-mercaptoethanol, 1,2-ethanedithiol, and 6-mercapto-1-hexanol. , 1-octyl mercaptan, 1-dodecyl mercaptan, 10-hydroxy-1-dodecyl mercaptan, 10-carboxy-1-dodecyl mercaptan, 10-amino-1-dodecyl mercaptan, 1- Sodium dodecyl mercaptan sulfonate, thiophenol, thiobenzoic acid, 4-amino-thiophenol, p-toluenethiol, 2,4-dimethylbenzenethiol, 3-mercapto-1,2, 4 triazole, 2-mercapto-benzothiazole. Among these compounds, 3-mercapto-1,2 propylene glycol is preferred from the viewpoint of water solubility and waste disposal.

In the step of forming the release layer, a compound having two or less mercapto groups in the molecule can be used in the form of an aqueous solution. To increase the solubility in water, an alcohol such as methanol or ethanol may be added. The addition of an alcohol is particularly effective when a "compound having a high hydrophobicity and having two or less mercapto groups in the molecule" is used.

When the concentration of the compound having two or less mercapto groups in the aqueous solution is high, the peel strength of the resin substrate and the metal foil tends to decrease. The concentration of the compound having two or less mercapto groups in the molecule can be adjusted by Adjust the peel strength. The concentration of the compound having two or less mercapto groups in the molecule in the aqueous solution is not limited, but can be set to 0.01 to 10.0% by weight, typically 0.1 to 5.0% by weight.

The pH value of the aqueous solution of a compound having two or less mercapto groups in the molecule is not particularly limited, and it can be used on either the acidic side or the basic side. For example, it can be used at pH values in the range of 3.0 to 10.0. From the viewpoint of not requiring special pH adjustment, it is preferably set to a pH in the range of 5.0 to 9.0 near neutrality, and more preferably set to a pH in the range of 7.0 to 9.0.

(3) metal alkoxide

The release layer may be composed of at least one type or two or more types selected from the group consisting of hydrolysis of aluminate compounds, titanate compounds, zirconate compounds, and aluminate compounds having a structure represented by the following formula: Products, hydrolysis products of titanate compounds, hydrolysis products of zirconate compounds, condensation products of hydrolysis products of aluminate compounds, condensation products of hydrolysis products of titanate compounds, and condensation products of hydrolysis products of zirconate compounds The structure of the compound in the formed group, or a structure obtained by mixing one or more kinds. Hereinafter, the condensate of this hydrolysate is also simply referred to as a metal alkoxide. By bonding the resin substrate and the metal foil with the release layer interposed therebetween, the adhesiveness is moderately reduced, and the peeling strength can be adjusted.

(R ¹ ) _m -M- (R ² ) _n

In the formula, R ¹ is an alkoxy group or a halogen atom, and R ² is a hydrocarbon group selected from the group consisting of an alkyl group, a cycloalkyl group, and an aryl group, or one or more hydrogen atoms of the hydrocarbon group are replaced by a halogen atom. Hydrocarbon group, M is any one of Al, Ti, Zr, n is 0, 1, or 2, m is an integer of 1 or more and M or less, and at least one of R ¹ is an alkoxy group; m + n is The valence of M; the valence of M is 3 in the case of Al, and 4 in the case of Ti and Zr.

The metal alkoxide must have at least one alkoxy group. When an alkoxy group is absent and only a hydrocarbon group selected from the group consisting of an alkyl group, a cycloalkyl group, and an aryl group, or a substituent composed of any of these hydrocarbon groups in which one or more hydrogen atoms are replaced by a halogen atom, There is a tendency that the adhesion between the resin substrate and the metal foil is excessively reduced. The metal alkoxide must have 0 to 2 hydrocarbon groups selected from the group consisting of an alkyl group, a cycloalkyl group, and an aryl group, or any of these hydrocarbon groups in which one or more hydrogen atoms are replaced by a halogen atom. The reason is that when there are three or more such hydrocarbon groups, the adhesiveness between the resin substrate and the metal foil tends to be excessively reduced. The alkoxy group also includes an alkoxy group in which one or more hydrogen atoms are replaced with a halogen atom. In terms of adjusting the peel strength of the resin substrate and the metal foil to the above range, the metal alkoxide preferably has two or more alkoxy groups and one or two of the above-mentioned hydrocarbon groups (including one or more hydrogen atoms by halogens). Atom-substituted hydrocarbyl).

The alkyl group is not limited, and examples thereof include methyl, ethyl, n- or iso-propyl, n-, iso- or third butyl, n-, iso-or neopentyl, n-hexyl, n-octyl, and n-decyl. The linear or branched chain is an alkyl group having 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms, and more preferably 1 to 5 carbon atoms.

In addition, the cycloalkyl group is not limited, and examples include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, and the like having 3 to 10 carbon atoms, and preferably 5 to 7 carbon atoms. Cycloalkyl.

Examples of the aromatic hydrocarbon group suitable as R ² include a phenyl group, an alkyl-substituted phenyl group (for example, tolyl, xylyl), 1- or 2-naphthyl, and anthracenyl. Aryl groups of -20, preferably 6-14, these hydrocarbon groups may contain either or both of a hydroxyl group and an amine group. One or more hydrogen atoms of these hydrocarbon groups may be substituted with a halogen atom, and may be substituted with, for example, a fluorine atom, a chlorine atom, or a bromine atom.

As examples of preferred aluminate compounds, trimethoxyaluminum, methyldimethoxyaluminum, ethyldimethoxyaluminum, n- or isopropyldimethoxyaluminum, n-, iso-or Third butyldimethoxyaluminum, n-, iso-or neopentyldimethoxyaluminum, hexyldimethoxyaluminum, octyldimethoxyaluminum, decyldimethoxyaluminum, phenyldimethyl Aluminum oxide; alkyl-substituted phenyldimethoxyaluminum (e.g., p- (methyl) phenyldimethoxyaluminum), dimethylaluminum, triethoxyaluminum, methyldioxy Aluminum ethoxylate, ethyl diethoxy aluminum, n- or isopropyl diethoxy aluminum, n-, iso- or third butyl diethoxy aluminum, pentyl diethoxy aluminum, hexyl diethoxy Aluminum, octyl diethoxy aluminum, decyl diethoxy aluminum, phenyl diethoxy aluminum, alkyl substituted phenyl diethoxy aluminum (e.g., p- (methyl) phenyl dieth Ethoxy aluminum), dimethyl ethoxy aluminum, triisopropoxy aluminum, methyl diisopropoxy aluminum, ethyl diisopropoxy aluminum, n- or isopropyl diethoxy aluminum, N-, i- or third butyl aluminum diisopropoxide, aluminum pentyl diisopropoxide, Aluminum diisopropoxy aluminum, octyl diisopropoxy aluminum, decyl diisopropoxy aluminum, phenyl diisopropoxy aluminum, alkyl substituted phenyl diisopropoxy aluminum (e.g., P- (methyl) phenyldiisopropoxyaluminum), dimethylisopropoxyaluminum, (3,3,3-trifluoropropyl) dimethoxyaluminum, and tridecylfluorooctyldiethyl Aluminium oxide, methyl aluminum dichloride, dimethyl aluminum chloride, dimethyl aluminum chloride, phenyl aluminum dichloride, dimethyl aluminum fluoride, dimethyl aluminum bromide, diphenyl bromide Aluminum compounds, hydrolysates of these compounds, and condensates of the hydrolysates of these compounds. Among these compounds, trimethoxyaluminum, triethoxyaluminum, and triisopropoxyaluminum are preferred from the viewpoint of easy availability.

As examples of preferred titanate compounds, tetramethoxytitanium, methyltrimethoxytitanium, ethyltrimethoxytitanium, n- or isopropyltrimethoxytitanium, n-, iso-or third Butyltrimethoxytitanium, n-, iso-or neopentyltrimethoxytitanium, hexyltrimethoxytitanium, octyltrimethoxytitanium, decyltrimethoxytitanium, phenyltrimethoxytitanium; alkyl substituted Phenyltrimethoxytitanium (e.g., p- (meth) phenyltrimethoxytitanium), dimethyldimethoxytitanium, tetraethoxytitanium, methyltriethoxytitanium, ethyltriethyl Titanium oxytitanium, n- or iso-propyl triethoxy titanium, n-, iso- or tri-butyl triethoxy titanium, pentyl triethoxy titanium, hexyl triethoxy titanium, octyl triethoxy Titanium, decyltriethoxytitanium, phenyltriethoxytitanium, alkyl-substituted phenyltriethoxytitanium (e.g., p- (meth) phenyltriethoxytitanium), dimethyl Titanium diethoxy, titanium tetraisopropoxide, titanium methyl triisopropoxide, titanium ethyl triisopropoxide, titanium n- or isopropyl triethoxy, n-, iso- or third butyl Titanium triisopropoxide, pentyl titanium triisopropoxide Hexyltriisopropoxytitanium, octyltriisopropoxytitanium, decyltriisopropoxytitanium, phenyltriisopropoxytitanium, alkyl substituted phenyltriisopropoxytitanium (e.g. , P- (meth) phenyltriisopropoxytitanium), dimethyldiisopropoxytitanium, (3,3,3-trifluoropropyl) trimethoxytitanium, and tridecylfluorooctyltris Titanium ethoxylate, methyl titanium trichloride, dimethyl titanium dichloride, trimethyl titanium chloride, phenyl titanium trichloride, dimethyl titanium difluoride, dimethyl titanium dibromide, Diphenyl titanium dibromide, hydrolysis products of these compounds, and condensates of the hydrolysis products of these compounds, and the like. Among these compounds, tetramethoxytitanium, tetraethoxytitanium, and tetraisopropoxytitanium are preferred from the viewpoint of easy availability.

As examples of preferred zirconate compounds, tetramethoxyzirconium, methyltrimethoxyzirconium, ethyltrimethoxyzirconium, n- or isopropyltrimethoxyzirconium, n-, iso-, or third Butyltrimethoxyzirconium, n-, iso- or neopentyltrimethoxyzirconium, hexyltrimethoxyzirconium, octyltrimethoxyzirconium, decyltrimethoxyzirconium, phenyltrimethoxyzirconium; alkyl substituted Phenyltrimethoxyzirconium (e.g., p- (methyl) phenyltrimethoxyzirconium), dimethyldimethoxyzirconium, tetraethoxyzirconium, methyltriethoxyzirconium, ethyltriethyl Zirconyloxy, n- or isopropyltriethoxyzirconium, n-, iso-or tributylzirconate, pentyltriethoxyzirconium, hexyltriethoxyzirconium, octyltriethoxy Zirconium, decyltriethoxyzirconium, phenyltriethoxyzirconium, alkyl-substituted phenyltriethoxyzirconium (e.g., p- (meth) phenyltriethoxyzirconium), dimethyl Zirconium diethoxy, zirconium tetraisopropoxide, zirconium methyl triisopropoxide, zirconium ethyl triisopropoxide, zirconium or isopropyl triethoxylate, n-, iso- or third butyl Zirconium triisopropoxide, zirconyl pentyl triisopropoxide Hexyl triisopropoxy zirconium, octyl triisopropoxy zirconium, decyl triisopropoxy zirconium, phenyl triisopropoxy zirconium, alkyl substituted phenyl triisopropoxy zirconium (e.g. , (P- (meth) phenyltriisopropoxytitanium), dimethyldiisopropoxyzirconium, (3,3,3-trifluoropropyl) trimethoxyzirconium, and tridecylfluorooctyltrioxane Zirconyl ethoxylate, methyl zirconium trichloride, dimethyl zirconium dichloride, trimethyl zirconium chloride, phenyl zirconium trichloride, dimethyl zirconium difluoride, dimethyl zirconium dibromide, Diphenyl zirconium dibromide, hydrolysis products of these compounds, and condensates of the hydrolysis products of these compounds, and the like. Among these compounds, tetramethoxyzirconium, tetraethoxyzirconium, and tetraisopropoxyzirconium are preferred from the viewpoint of easy availability.

In the step of forming the release layer, the metal alkoxide can be used in the form of an aqueous solution. To increase the solubility in water, alcohols such as methanol or ethanol may be added. The addition of alcohols is particularly effective when a highly hydrophobic metal alkoxide is used.

When the concentration of the metal alkoxide in the aqueous solution is high, the peel strength of the resin substrate and the metal foil tends to decrease, and the peel strength can be adjusted by adjusting the metal alkoxide concentration. The concentration of the metal alkoxide in the aqueous solution is not limited, and can be set to 0.001 to 1.0 mol / L, and typically can be set to 0.005 to 0.2 mol / L.

The pH of the metal alkoxide aqueous solution is not particularly limited, and it can be used on either the acidic side or the alkaline side. For example, it can be used at pH values in the range of 3.0 to 10.0. From the viewpoint of not requiring special pH adjustment, it is preferably set to a pH in the range of 5.0 to 9.0 near neutrality, and more preferably set to a pH in the range of 7.0 to 9.0.

(4) Other

A well-known release material such as a silicon-based release agent, a resin film having a release property, and the like can be used for the release layer.

The metal foil may be provided between the first surface of the metal foil and / or the second surface of the metal foil, and / or the metal foil and the release layer, and is selected from a roughened layer, a heat-resistant layer, a rust-proof layer, and chromium. One or more layers in the group consisting of a salt treatment layer and a silane coupling treatment layer. The chromate treatment layer herein refers to a layer treated with a liquid containing chromic anhydride, chromic acid, dichromic acid, chromate, or dichromate. The chromate treatment layer may also contain elements such as cobalt, iron, nickel, molybdenum, zinc, tantalum, copper, aluminum, phosphorus, tungsten, tin, arsenic, and titanium (may also be metals, alloys, oxides, nitrides, sulfurized And other forms). Specific examples of the chromate treatment layer include a chromate treatment layer treated with an aqueous solution of chromic anhydride or potassium dichromate, or chromium treated with a treatment solution containing chromic anhydride or potassium dichromate and zinc. Acid treatment layer, etc.

The roughened layer can be formed by, for example, the following processes.

[Spherical roughening]

Spherical roughened particles were formed using a copper roughening plating bath described below consisting of Cu, H ₂ SO ₄ , and As.

‧Liquid composition 1

CuSO ₄ ‧5H ₂ O 78 ~ 196g / L

Cu 20 ~ 50g / L

H ₂ SO ₄ 50 ~ 200g / L

Arsenic 0.7 ~ 3.0g / L

(Electric plating temperature 1) 30 ~ 76 ℃

(Current condition 1) Current density 35 ~ 105A / dm ² (above the limiting current density of the plating bath)

(Plating time 1) 1 ~ 240 seconds

Then, a copper electrolytic bath made of sulfuric acid-copper sulfate was used for covering plating to prevent the coarse particles from falling off and to increase the peeling strength. The covering plating conditions are described below.

‧Liquid composition 2

CuSO ₄ ‧5H ₂ O 88 ~ 352g / L

Cu 22 ~ 90g / L

H ₂ SO ₄ 50 ~ 200g / L

(Electrical plating temperature 2) 25 ~ 80 ℃

(Current condition 2) Current density: 15 ~ 32A / dm ² (less than the limiting current density of the plating bath)

(Plating time 1) 1 ~ 240 seconds

Moreover, a well-known heat-resistant layer and a rust-proof layer can be used as a heat-resistant layer and a rust-proof layer. For example, the heat-resistant layer and / or the rust-proof layer may be selected from the group consisting of nickel, zinc, tin, cobalt, molybdenum, copper, tungsten, phosphorus, arsenic, chromium, vanadium, titanium, aluminum, gold, silver, platinum group elements, iron And a layer of one or more elements in the group consisting of tantalum and tantalum may be selected from the group consisting of nickel, zinc, tin, cobalt, molybdenum, copper, tungsten, phosphorus, arsenic, chromium, vanadium, titanium, aluminum, gold, A metal layer or an alloy layer composed of one or more elements of a group of silver, platinum group elements, iron, and tantalum. The heat-resistant layer and / or the rust-preventive layer may include oxides, nitrides, and silicides. These oxides, nitrides, and silicides are selected from the group consisting of nickel, zinc, tin, cobalt, molybdenum, copper, tungsten, phosphorus, One or more elements from the group of arsenic, chromium, vanadium, titanium, aluminum, gold, silver, platinum group elements, iron, and tantalum. The heat-resistant layer and / or the rust preventive layer may be a layer containing a nickel-zinc alloy. The heat-resistant layer and / or the rust preventive layer may be a nickel-zinc alloy layer. In addition to unavoidable impurities, the above nickel-zinc alloy layer may contain 50 wt% to 99 wt% nickel and 50 wt% to 1 wt% zinc. The total adhesion amount of zinc and nickel in the nickel-zinc alloy layer may be 5 to 1000 mg / m ² , preferably 10 to 500 mg / m ² , and preferably 20 to 100 mg / m ² . Furthermore, the ratio of the nickel adhesion amount to the zinc adhesion amount (= nickel adhesion amount / zinc adhesion amount) of the nickel-zinc alloy-containing layer or the nickel-zinc alloy layer is preferably 1.5 to 10. The nickel adhesion amount of the nickel-zinc alloy layer or the nickel-zinc alloy layer is preferably 0.5 mg / m ² to 500 mg / m ² , and more preferably 1 mg / m ² to 50 mg / m ² .

For example, the heat-resistant layer and / or the rust-proof layer may be a nickel or nickel alloy layer with an adhesion amount of 1 mg / m ² to 100 mg / m ² , preferably 5 mg / m ² to 50 mg / m ² , and an adhesion amount of 1 mg. / m ² to 80 mg / m ² , preferably 5 mg / m ² to 40 mg / m ^{2 of} a tin layer made of a heat-resistant layer and / or a rust-proof layer. The nickel alloy layer may be made of nickel-molybdenum, nickel-zinc, It is composed of any one of nickel-molybdenum-cobalt. The total adhesion amount of nickel or nickel alloy and tin in the heat-resistant layer and / or the rust-proof layer is preferably 2 mg / m ² to 150 mg / m ² , and more preferably 10 mg / m ² to 70 mg / m ² . In addition, the heat-resistant layer and / or the rust-preventive layer is preferably [the nickel adhesion amount in nickel or a nickel alloy] / [tin adhesion amount] = 0.25 to 10, and more preferably 0.33 to 3.

In addition, as the silane coupling agent used for the silane coupling treatment, a well-known silane coupling agent can be used, and for example, an amine-based silane coupling agent, an epoxy-based silane coupling agent, or a mercapto-based silane coupling agent can be used. Furthermore, as the silane coupling agent, vinyltrimethoxysilane, vinylphenyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, and γ-glycidyloxypropyltrimethoxy may also be used. Silane, 4-glycidylbutyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, N-3- (4- (3-Aminopropoxy) butoxy) propyl-3-aminopropyltrimethoxysilane, imidazolane, tris Silane, γ-mercaptopropyltrimethoxysilane and the like.

The silane coupling treatment layer can be formed using a silane coupling agent such as epoxy-based silane, amine-based silane, methacryloxy-based silane, or mercapto-based silane. In addition, such a silane coupling agent may be used by mixing two or more kinds. Among these, a silane coupling treatment layer formed using an amine-based silane coupling agent or an epoxy-based silane coupling agent is preferred.

The amine-based silane coupling agent mentioned here may be selected from the group consisting of N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, and 3- (N-styrylmethyl-2-amine. Ethylethylamino) propyltrimethoxysilane, 3-aminopropyltriethoxysilane, bis (2-hydroxyethyl) -3-aminopropyltriethoxysilane, aminopropyl Trimethoxysilane, N-methylaminopropyltrimethoxysilane, N-phenylaminopropyltrimethoxysilane, N- (3-propenyloxy-2-hydroxypropyl) -3- Aminopropyltriethoxysilane, 4-aminobutyltriethoxysilane, (aminoethylaminomethyl) phenethyltrimethoxysilane, N- (2-aminoethyl- 3-aminopropyl) trimethoxysilane, N- (2-aminoethyl-3-aminopropyl) tri (2-ethylhexyloxy) silane, 6- (aminohexylaminopropyl) ) Trimethoxysilane, aminophenyltrimethoxysilane, 3- (1-aminopropyloxy) -3,3-dimethyl-1-propenyltrimethoxysilane, 3-aminopropyl Tris (methoxyethoxyethoxy) silane, 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, ω-aminoundecyltrimethoxysilane , 3- (2-N-benzyl Aminoethylaminopropyl) trimethoxysilane, bis (2-hydroxyethyl) -3-aminopropyltriethoxysilane, (N, N-diethyl-3-aminopropyl) ) Trimethoxysilane, (N, N-dimethyl-3-aminopropyl) trimethoxysilane, N-methylaminopropyltrimethoxysilane, N-phenylaminopropyltrimethoxy Silane, 3- (N-styrylmethyl-2-aminoethylamino) propyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β (aminoethyl ) group consisting of γ-aminopropyltrimethoxysilane, N-3- (4- (3-aminopropyloxy) butoxy) propyl-3-aminopropyltrimethoxysilane Amine-based silane coupling agent.

The silane coupling treatment layer is preferably 0.05 mg / m ² to 200 mg / m ² in terms of silicon atom conversion, preferably 0.15 mg / m ² to 20 mg / m ² , and preferably 0.3 mg / m ² to 2.0 mg / m ² is set. When it is the said range, the adhesiveness of a resin base material and a metal foil can be improved more.

In addition, the surface of metal foil, roughened particle layer, heat-resistant layer, rust-proof layer, silane coupling treatment layer, chromate treatment layer or release layer can be subjected to International Publication No. WO2008 / 053878, Japanese Patent Application Laid-Open No. 2008-111169 , Japanese Patent No. 5024930, International Publication No. WO2006 / 028207, Japanese Patent No. 4828427, International Publication No. WO2006 / 134868, Japanese Patent No. 5046927, International Publication No. WO2007 / 105635, Japanese Patent No. 5180815, Japanese Patent Laid-Open No. 2013 Surface treatment described in -19056. In this way, the metal foil of the present invention includes a surface-treated metal foil.

The first surface of the metal foil may be provided on one or more layers selected from the group consisting of a roughened layer, a heat-resistant layer, a rust-proof layer, a chromate-treated layer, and a silane coupling-treated layer. There is a resin layer.

The resin layer provided on the first surface of the metal foil may be an adhesive resin, that is, an adhesive, a primer, or a semi-hardened (B-stage state) insulating resin layer for adhesive use. The so-called semi-hardened state (B-stage state) includes states in which even if the surface of the insulating resin layer is touched with a finger, there is no stickiness. The above-mentioned insulating resin layer can be stacked and stored. If further heat treatment is performed, hardening occurs. reaction. The resin layer on the surface of the metal foil is preferably a resin layer that exhibits a moderate peel strength (for example, 2 gf / cm to 200 gf / cm) when it comes into contact with the release layer. Furthermore, it is preferable to use a resin that follows the unevenness of the surface of the metal foil and is difficult to mix in voids or air bubbles that cause bulging. For example, when the resin layer is provided on the surface of a metal foil, it is preferable to use a resin having a low viscosity such as a resin viscosity of 10,000 mPa · s (25 ° C) or less, and more preferably a resin viscosity of 5000 mPa · s (25 ° C) or less Resin layer. By providing the above-mentioned resin layer between the insulating substrate and the metal foil of the metal foil, the resin layer can follow the surface of the metal foil even when an insulating substrate that is difficult to follow the surface irregularities of the metal foil is used. This is effective because it is difficult to generate voids or bubbles between the insulating substrates.

The resin layer provided on the first surface of the metal foil may include a thermosetting resin or a thermoplastic resin. The resin layer on the surface of the metal foil may include a thermoplastic resin. The resin layer on the surface of the metal foil may include a well-known resin, a resin hardener, a compound, a hardening accelerator, a dielectric, a reaction catalyst, a crosslinking agent, a polymer, a prepreg, a skeleton material, and the like. Further, as the resin layer on the surface of the metal foil, for example, International Publication No. WO2008 / 004399, International Publication No. WO2008 / 053878, International Publication No. WO2009 / 084533, Japanese Patent Application Laid-Open No. 11-5828, Japanese Patent Application Laid-Open No. 11-140281, and Japan Patent No. 3184485, International Publication No. WO97 / 02728, Japanese Patent No. 3676375, Japanese Patent Laid-Open No. 2000-43188, Japanese Patent No. 3612594, Japanese Patent Laid-Open No. 2002-179772, Japanese Patent Laid-Open No. 2002-359444, Japanese Patent No. No. 2003-304068, Japanese Patent No. 3992225, Japanese Patent Laid-Open No. 2003-249739, Japanese Patent No. 4136509, Japanese Patent Laid-Open No. 2004-82687, Japanese Patent No. 4025177, Japanese Patent Laid-Open No. 2004-349654, Japanese Patent No. 4286060, Japanese Patent Laid-Open No. 2005-262506, Japanese Patent No. 4570070, Japanese Patent Laid-Open No. 2005-53218, Japanese Patent No. 3949676, Japanese Patent No. 4178415, International Publication No. WO2004 / 005588, Japanese Patent Laid-Open 2006- 257153, Japanese Patent Laid-Open No. 2007-326923, Japanese Patent Laid-Open No. 2008-111169, Japanese Patent No. 5024930, International Publication No. WO2006 / 028207, Japanese Patent No. 4828427 Japanese Patent Laid-Open No. 2009-67029, International Publication No. WO2006 / 134868, Japanese Patent No. 5046927, Japanese Patent Laid-Open No. 2009-173017, International Publication No. WO2007 / 105635, Japanese Patent No. 5180815, International Publication No. WO2008 / 114858, International The substances described in Publication No. WO2009 / 008471, Japanese Patent Laid-Open No. 2011-14727, International Publication No. WO2009 / 001850, International Publication No. WO2009 / 145179, International Publication No. WO2011 / 068157, and Japanese Patent Laid-Open No. 2013-19056 (resins, Resin hardeners, compounds, hardening accelerators, dielectrics, reaction catalysts, cross-linking agents, polymers, prepregs, framework materials, etc.) and / or a method for forming a resin layer and a forming apparatus.

(Laminates, Semiconductor Packaging, Electronic Equipment)

A metal foil with a release layer and a resin substrate provided on the metal foil with a release layer can be laminated to produce a laminate. The laminated body can use paper substrate phenol resin, paper substrate epoxy resin, synthetic fiber cloth substrate epoxy resin, glass cloth-paper composite substrate epoxy resin, glass cloth-glass non-woven fabric composite substrate epoxy resin, and The glass cloth substrate epoxy resin and the like form a resin substrate. The resin substrate may be a prepreg or may include a thermosetting resin. Furthermore, by forming a circuit on the metal foil of this laminated body, a printed wiring board can be produced. Furthermore, by mounting electronic components on a printed wiring board, a printed wiring board can be manufactured. In the present invention, the "printed wiring board" includes a printed wiring board, a printed circuit board, and a printed circuit board on which electronic components and the like are mounted. Furthermore, an electronic device may be manufactured using the printed wiring board, an electronic device may be manufactured using the printed circuit board on which electronic components are mounted, or an electronic device may be manufactured using the printed circuit board on which the electronic components are mounted. The "printed circuit board" also includes a circuit-forming substrate for a semiconductor package. Furthermore, a semiconductor package can be produced by mounting electronic components on a circuit forming substrate for a semiconductor package. Furthermore, an electronic device can be manufactured using this semiconductor package.

(Manufacturing method of printed wiring board)

An aspect of the method for manufacturing a printed wiring board of the present invention includes the steps of: bonding an insulating substrate to the metal foil with a release layer of the present invention; and removing the metal foil with a release layer from the insulating substrate without being etched. Peeling to obtain an insulating substrate on which the surface profile of the metal foil with a release layer is transferred on the peeling surface; and forming a circuit on the peeling surface side of the insulating substrate to which the surface profile is transferred. With this configuration, the physical peeling of the resin base material when the metal foil is bonded to the resin base material is realized, and in the step of removing the metal foil from the resin base material, it is possible to transfer from the surface of the metal foil to the surface without damage. In the case of the surface profile of the surface of the resin substrate, the metal foil is removed at low cost. In this manufacturing method, a circuit may be formed using a plating pattern. In this case, after forming a plating pattern, a desired circuit can be formed using this plating pattern, and a printed wiring board can be manufactured. Furthermore, a circuit may be formed using a printed pattern. In this case, for example, after a printed pattern is formed using inkjet containing a conductive paste or the like in the ink, a desired printed circuit can be formed using the printed pattern to produce a printed wiring board.

The "surface profile" as used in this specification means the uneven | corrugated shape of a surface.

Another aspect of the method for manufacturing a printed wiring board of the present invention includes the steps of: bonding an insulating substrate to the metal foil with a release layer of the present invention; and removing the metal foil with a release layer from the insulation without being etched. The substrate is peeled off to obtain an insulating substrate having a surface profile of a metal foil with a release layer transferred on the peeling surface; and an additional layer is provided on the peeling surface side of the insulating substrate having the surface profile transferred. With this configuration, the physical peeling of the resin base material when the metal foil is bonded to the resin base material is realized, and the step of removing the metal foil from the resin base material can be transferred to the surface of the resin base material without damage. In the case of a contour of the surface of the metal foil, the metal foil is removed at low cost. In addition, the resin component of the resin substrate and the resin component of the build-up layer may be different or the same depending on the predetermined uneven surface transferred to the resin substrate, and the two can be adhered with good adhesion.

The "build-up layer" herein refers to a layer having a conductive layer, a wiring pattern or a circuit, and an insulator such as a resin. The shape of the insulator such as a resin may be a layer. The conductive layers, wiring patterns, and insulators such as circuits and resins may be provided in any way.

The build-up layer can be produced by providing a conductive layer, a wiring pattern, an insulator such as a circuit, and a resin on the peeling surface side of the resin substrate on which the surface contour of the metal foil is transferred on the peeling surface. As a method for forming a conductive layer, a wiring pattern, or a circuit, a well-known method such as a semi-additive method, a full-additive method, a subtractive method, or a partial addition method can be used.

The build-up layer may have a plurality of layers, or may have a plurality of conductive layers, wiring patterns or circuits, and a resin (layer).

The plurality of conductive layers, wiring patterns, or circuits may be electrically insulated by an insulator such as a resin. By forming a through hole and / or a blind hole in an insulator such as a resin by using a laser and / or a drill, a conductive plating such as copper plating can be formed in the through hole and / or the blind hole, so as to electrically insulate a large amount of electricity. Each conductive layer, wiring pattern or circuit is electrically connected.

The resin, resin layer, and resin substrate described in this specification can be used as an insulator such as a resin constituting such a layer, and a well-known resin, resin layer, resin substrate, insulator, prepreg can be used, and the resin can be impregnated into glass cloth. And the like. The resin may include an inorganic substance and / or an organic substance. In addition, as the resin constituting the build-up layer, materials having a low relative dielectric constant such as LCP (liquid crystal polymer), fluororesin, low dielectric constant polyimide, polyphenylene ether, cycloolefin polymer, or polytetrafluoroethylene can be used. form. In recent years, with the increase of high-frequency products, the following actions have increased, that is, LCP (liquid crystal polymer), fluororesin, low dielectric constant polyimide, polyphenylene ether, cycloolefin polymer or polytetramethylene A structure in which a material having a low relative dielectric constant such as vinyl fluoride (Teflon: registered trademark) is incorporated in a printed circuit board. At this time, since these materials are thermoplastic, shape changes cannot be avoided during hot pressing. If LCP (liquid crystal polymer), fluororesin, low dielectric constant polyfluorene imide, polyphenylene ether, and cycloolefin polymer are used, Or the polytetrafluoroethylene monomer constitutes the substrate, and there is a problem that the production yield does not increase this in the basic mass production. If the above-mentioned manufacturing method of the present invention is used, it is possible to provide excellent high-frequency characteristics and prevent heating by using a thermosetting resin such as epoxy resin as a resin substrate and bonding it to such a problem. Deformed printed wiring board.

Another aspect of the method for manufacturing a printed wiring board of the present invention is a method of manufacturing a printed wiring board including the steps of: from the release layer side metal foil of the present invention or the metal foil of the present invention, An insulating substrate 1 is bonded to the second surface side of the metal foil; a circuit is formed on the first surface side of the metal foil with the release layer or the metal foil laminated on the insulating substrate 1; and the circuit is covered by the insulating substrate 2 Burying the circuit in the insulating substrate 2; peeling the insulating substrate 1 from the metal foil with the release layer or the metal foil to expose the metal foil with the release layer or the metal foil; and releasing the exposed mold with the release The metal foil or the above-mentioned metal foil is removed.

Furthermore, another aspect of the method for manufacturing a printed wiring board of the present invention includes the step of: in the metal foil with a release layer of the present invention or the metal foil of the present invention, from the release layer side or the second surface of the metal foil. Laminate the insulating substrate 1 on the side; laminate a dry film on the first side of the metal foil with a release layer or the metal foil on which the insulating substrate 1 is laminated; pattern the dry film to form a circuit; peel the dry film The circuit is exposed; the circuit is buried in the insulating substrate 2 by covering the exposed circuit with the insulating substrate 2; the insulating substrate 1 is peeled from the metal foil with a release layer or the metal foil to expose the adhesion The mold layer metal foil or the metal foil; and removing the exposed metal foil with the release layer or the metal foil.

It is possible to manufacture the metal foil at a low cost by providing "a metal foil in which a release layer is provided on a metal foil whose surface unevenness is controlled as described above, and the resin substrate can be physically separated when the metal foil is bonded to the resin substrate". A printed wiring board having a fine circuit. In addition, physical peeling of the resin base material when the metal foil is bonded to the resin base material can be achieved, and in the step of removing the metal foil from the resin base material, the metal foil transferred to the surface of the resin base material can be prevented from being damaged. In the case of a surface profile, the metal foil is removed at low cost.

Here, a specific example of a method for manufacturing a printed wiring board using the release-layer-attached metal foil of the present invention will be described in detail using drawings.

First, as shown in FIG. 1-A, a metal foil with a release layer (first layer) is prepared. The metal foil with a release layer (first layer) is laminated on a resin substrate from the mold release layer side.

Then, as shown in FIG. 1-B, a resist is coated on the metal foil, and exposure and development are performed to etch the resist into a predetermined shape.

Then, as shown in FIG. 1-C, the circuit is plated in a predetermined shape by removing the resist after the circuit plating is formed.

Then, as shown in Fig. 2-D, a buried resin is laminated on the metal foil so as to cover the circuit plating (by the buried circuit plating), and then the resin layer is laminated, and then from the first metal foil side, another A metal foil with a release layer (second layer).

Then, as shown in FIG. 2-E, the resin substrate is peeled from the second layer metal foil with a release layer.

Then, as shown in FIG. 2-F, laser drilling is performed at a specified position of the resin layer to expose the circuit plating and form a blind hole.

Then, as shown in Fig. 3-G, copper is buried in the blind hole to form a filled hole.

Then, as shown in FIG. 3-H, a circuit plating is formed on the filled hole in the manner of FIG. 1-B and FIG. 1-C described above.

Then, as shown in FIG. 3-I, the resin substrate was peeled from the 1st metal foil with a release layer.

Then, as shown in FIG. 4-J, the metal foils on both surfaces are removed by rapid etching to expose the surface of the circuit plating in the resin layer.

Then, as shown in FIG. 4-K, bumps are formed on the circuit plating in the resin layer, and copper pillars are formed on the solder. In this way, a printed wiring board using the metal foil with a release layer of the present invention was produced.

In addition, in the method for manufacturing a printed wiring board described above, a circuit can be formed on the resin substrate side surface of the metal foil with a release layer by replacing the "metal foil" with a resin substrate and the "resin substrate" with a metal foil. The circuit is embedded with resin to manufacture a printed wiring board.

As the other metal foil with a release layer (second layer), the metal foil with a release layer of the present invention can be used, and the conventional metal foil with a mold release layer can be used, and a common copper foil can also be used. Furthermore, one or more layers of circuits can be formed on the second layer circuit shown in Fig. 3-H. Any of the semi-additive method, the subtractive method, the partial additive method, or the modified semi-additive method can be used. Method to form these circuits.

According to the method for manufacturing a printed wiring board as described above, the circuit plating is embedded in the resin layer. Therefore, when the metal foil is removed by rapid etching as shown in Fig. 4-J, the circuit plating is subjected to resin. The protection of the layer maintains the shape of the circuit plating, thereby easily forming a fine circuit. In addition, since the circuit plating is protected by the resin layer, the migration resistance is improved, and the conduction of the circuit wiring is well suppressed. Therefore, it is easy to form a fine circuit. Furthermore, when the metal foil is removed by rapid etching as shown in FIGS. 4-J and 4-K, the exposed surface of the circuit plating becomes a shape recessed from the resin layer, so it is easy to form bumps on the circuit plating. And further forming a copper pillar on the bump, the manufacturing efficiency is improved.

As the resin, a well-known resin or prepreg can be used. For example, BT (bismaleimide ) Resin or glass cloth impregnated with BT resin is prepreg, ABF film or ABF manufactured by Ajinomoto Fine Chemical Co., Ltd. As the resin, the resin layer and / or resin and / or prepreg described in this specification can be used.

In addition, the metal foil with a release layer used for the first layer may have a substrate or a resin layer on a surface of the metal foil with a release layer. By having the above-mentioned substrate or resin layer, there is an advantage that the metal foil with a release layer used in the first layer is supported, and wrinkles are not easily generated, so productivity is improved. In addition, any substrate or resin layer can be used for the substrate or resin layer as long as it has the effect of supporting the metal foil with a release layer used in the first layer. For example, the carrier, prepreg, resin layer, or a well-known carrier, prepreg, resin layer, metal plate, metal foil, inorganic compound plate, inorganic compound foil, organic compound plate, or organic compound described in the description of the present application can be used. The foil serves as the substrate or resin layer.

A schematic diagram of the semi-additive method using the surface profile of the metal foil is shown in FIG. 5. In this semi-additive method, a surface profile of a metal foil is used. Specifically, first, the metal foil with a release layer of the present invention is laminated on a resin substrate from the release layer side to produce a laminate. Then, the metal foil of the laminated body is removed or peeled by etching. Then, the surface of the resin substrate to which the surface contour of the metal foil is transferred is washed with dilute sulfuric acid or the like, and then electroless copper plating is performed. Next, a portion of the resin substrate on which the circuit is not formed is covered with a dry film or the like, and the surface of the electroless copper plating layer not covered with the dry film is subjected to electrical (electrolytic) copper plating. Then, after the dry film is removed, the electroless copper plating layer formed on the portion where the circuit is not formed is removed, thereby forming a fine circuit. The fine circuit formed in the present invention is in close contact with the peeling surface of the resin substrate to which the surface contour of the metal foil of the present invention is transferred, so that its adhesion (peeling strength) is good.

In addition, another embodiment of the semi-additive method is as described above.

The so-called semi-additive method refers to a method of forming a conductor pattern by using thin electroless plating on a resin substrate or metal foil to form a pattern, and then using electrical plating and etching. Therefore, one embodiment of the method for manufacturing a printed wiring board of the present invention using the semi-additive method includes the following steps: preparing the metal foil of the present invention or the metal foil with a release layer of the present invention and a resin substrate; and from the surface Laminate the resin substrate on the metal foil or the metal foil with release layer on the side whose profile is controlled or on the release layer side; after laminating the metal foil and the resin substrate, remove or peel the metal foil by etching; Through holes or / and blind holes are provided on the exposed or peeled surface of the resin substrate resulting from the removal or peeling of the metal foil; the area containing the through holes or / and the blind holes is subjected to slag removal treatment; Materials and areas containing the above-mentioned through holes or / and blind holes, the surface of the resin substrate is washed with dilute sulfuric acid, etc., and an electroless plating layer (such as an electroless copper plating layer) is provided; Plating resist; exposing the above plating resist, and then removing the plating resist in the area where the circuit is formed; providing electrolytic plating in the area where the above circuit is formed, from which the plating resist is removed (E.g., an electrolytic copper plating layer); and removing the plating resist; electroless plating region other than the region by etching or the like located rapidly formed with the cladding layer removal circuit.

Another embodiment of the method for manufacturing a printed wiring board of the present invention using the semi-additive method includes the following steps: preparing the metal foil of the present invention or the metal foil with a release layer of the present invention and a resin substrate; obtained from a surface profile Laminate the resin substrate on the controlled side or the release layer side on the metal foil or the metal foil with release layer; after laminating the metal foil and the resin substrate, remove or peel the metal foil by etching; for removal Or the exposed or peeled surface of the resin substrate produced by peeling the metal foil, the surface of the resin substrate is washed with dilute sulfuric acid, etc., and an electroless plating layer (for example, an electroless copper plating layer) is provided; A plating resist is provided on the cladding layer; the plating resist is exposed, and then the plating resist in the area where the circuit is formed is removed; an electrolytic plating is provided in the area where the circuit is formed where the plating resist is removed A cladding layer (such as an electrolytic copper plating layer); removing the above-mentioned plating resist; and removing the electroless plating layer located in a region other than the region where the circuit is formed by rapid etching or the like.

In this way, a circuit can be formed on the peeling surface of the resin base material after the metal foil is peeled off, so that a printed circuit forming substrate and a semiconductor package circuit forming substrate can be produced. Furthermore, a printed wiring board or a semiconductor package can be produced using the circuit formation substrate. Furthermore, an electronic device can be manufactured using the printed wiring board and the semiconductor package.

On the other hand, in another embodiment of the method for manufacturing a printed wiring board of the present invention using the full-addition method, the following steps are included: a resin substrate is laminated on the metal from the side whose surface profile is controlled or the release layer side Foil or the metal foil with release layer; after laminating the metal foil and the resin substrate, the metal foil is removed or peeled by etching; the exposed or peeled surface of the resin substrate produced by removing or peeling the metal foil , Washing the surface of the resin substrate with dilute sulfuric acid, etc .; setting a plating resist on the surface of the washed resin substrate; exposing the plating resist, and then removing the plating resist in the area where the circuit is formed ; Providing an electroless plating layer (for example, an electroless copper plating layer and an electroless plating layer having a thickness) in an area where the circuit is formed, from which the plating resist is removed; and removing the plating resist.

In addition, the semi-additive method and the full-additive method may have the effect of easily providing an electroless plating layer by cleaning the surface of the resin substrate. In particular, when the mold release layer remains on the surface of the resin substrate, it may have the effect that part or all of the mold release layer is removed from the surface of the resin substrate by the cleaning. It is easier to set the electroless plating layer. This washing | cleaning can use the washing | cleaning by a well-known washing | cleaning method (the kind and temperature of the liquid used, the coating method of a liquid, etc.). Moreover, it is preferable to use the washing | cleaning method which can remove a part or all of the mold release layer of this invention.

In this way, a semi-additive method or a full-additive method can be used to form a circuit on the exposed or peeled surface of the resin base material after the metal foil is removed or peeled, thereby producing a printed circuit forming substrate and a semiconductor package circuit forming substrate. Furthermore, a printed wiring board and a semiconductor package can be produced using this circuit formation substrate. Furthermore, an electronic device can be manufactured using the printed wiring board and the semiconductor package.

[Example]

Examples of the present invention and experimental examples as comparative examples are disclosed below, but these examples are provided for better understanding of the present invention and its advantages, and are not intended to limit the invention.

‧Manufacture of green foil (copper foil before surface treatment)

(Examples 1 to 16, 19, and Comparative Examples 1 to 3)

A titanium rotating drum (electrolytic drum) was prepared. Then, it grinds according to the control conditions of the surface of the electrolytic drum described in Table 1, and manufactures the electrolytic drum which has a predetermined root mean square height Sq on the surface. Specifically, the surface of the electrolytic drum was polished using the number of polishing tapes described in Table 1. At this time, the grinding is performed while the grinding belt is wound around a specified width in the width direction of the drum and the grinding belt is moved in the width direction of the drum, while the drum is rotated to perform grinding. Table 1 shows the rotation speed of the drum surface during the above polishing. In addition, the polishing time is the product of the time that passes one point on the surface of the drum in one stroke and the number of strokes according to the width of the polishing belt and the moving speed of the polishing belt. Here, the single stroke of the polishing tape means that the surface of the rotating drum in the circumferential direction is polished once from the one end to the other end in the axial direction (the width direction of the electrolytic copper foil) of the polishing tape.

That is, the polishing time is expressed by the following mathematical formula.

Grinding time (minutes) = width of the grinding belt (cm / time) per stroke / moving speed of the grinding belt (cm / minute) × number of strokes (times)

For Examples 2, 5, 8, 14 to 16, and Comparative Example 3, when the surface of the electrolytic drum was polished, the surface of the drum was wet with water.

Then, the electrolytic drum is placed in the electrolytic cell, and electrodes are arranged around the drum at a predetermined distance between the electrodes. Then, in Examples 1 to 10, 12, 14 to 16, and Comparative Examples 2 and 3, electrolysis was performed in the electrolytic cell under the following conditions, the electrolytic drum was rotated, and copper was deposited on the surface of the electrolytic drum. Table 1 shows the current density and the linear velocity of the electrolyte at this time.

(Electrolyte composition)

Cu 120g / L

H ₂ SO ₄ 100g / L

70ppm ^- chloride ion (Cl)

6mg

Electrolyte temperature 60 ℃

In Examples 11, 19, and Comparative Example 1, 80 ppm of an additive bis (3-sulfopropyl) disulfide (SPS) was added to the electrolyte solution in an additional manner.

The composition of the electrolytic solution used in Example 13 was the same as that of Examples 1 to 10, 12, 14 to 16, and Comparative Examples 2, 3, except that the chloride ion concentration was set to 2 ppm or less, and 2 g of animal gum was added instead of fish gelatine. the same.

Then, the copper deposited on the surface of the electrolytic drum rotating forward was peeled off, and an electrolytic copper foil having a thickness described in Table 1 was continuously produced.

(Example 17)

The refined copper ingot was repeatedly rolled and annealed to a thickness of 0.2 mm. Then, final cold rolling was performed to make the thickness of the copper foil 80 μm. The final cold rolling workability was 60%. In addition, it is set as: rolling degree = (plate thickness before rolling-plate thickness after rolling) / plate thickness before rolling × 100%; and an oil film equivalent is set to 20,000.

The oil film equivalent is expressed by the following mathematical formula.

Oil film equivalent = {(rolled oil viscosity [cSt]) × (through plate speed [mpm] + roller speed [mpm])} / {(roller bite angle [rad]) × (material drop stress [kg / mm ² ])}

The rolling oil viscosity [cSt] is the dynamic viscosity at 40 ° C.

The calender roll used in the final cold rolling was a roll having a surface Sq = 0.20 μm. Regarding the surface adjustment of the calender roll, it is possible to reduce the value of Sq by making the grinding time longer than usual when grinding the calender roll. Further, by shortening the grinding time, the value of Sq can be increased.

(Example 18)

A copper alloy (brass) ingot with 25 mass% of Zn, Cu remaining and unavoidable impurities was repeatedly rolled and annealed to a thickness of 0.2 mm. Then, final cold rolling was performed under the following conditions to make the thickness of the copper foil 80 μm. The final cold rolling workability was 60%. Calendering degree = (sheet thickness before rolling-sheet thickness after rolling) / sheet thickness before rolling × 100%

The oil film equivalent is set to 20000.

The oil film equivalent is expressed by the following formula.

Oil film equivalent = {(rolled oil viscosity [cSt]) × (through plate speed [mpm] + roller speed [mpm])} / {(roller bite angle [rad]) × (material drop stress [kg / mm ² ])}

The rolling oil viscosity [cSt] is the dynamic viscosity at 40 ° C.

The calender roll used in the final cold rolling was a roll having a surface Sq = 0.20 μm. Regarding the surface adjustment of the calender roll, the value of Sq can be reduced by making the grinding time longer than usual when grinding the calender roll. Further, by shortening the grinding time, the value of Sq can be increased.

‧Surface treatment

Then, as the surface treatment, in the case of electrolytic copper foil, the M surface (precipitated surface, matte surface) of the green foil is treated as described below, and in the case of rolled copper foil, any surface of the green foil is treated as described below. That is, each of the roughening treatment, heat-resistant treatment, rust prevention treatment, silane coupling treatment, and resin layer forming treatment is performed under each condition shown below, or each treatment is performed in combination. Next, a release layer was formed on the treated side surface of the copper foil under the conditions shown below. In addition, unless otherwise specified, each process is performed in the order described above. In addition, when "None" is described in each processing column in Table 1, it means that these processings were not performed. In addition, Examples 5, 7, 8, and 10 also performed the same treatment as that of the M surface on the S surface (the surface on the drum side, the smooth surface, and the glossy surface). In the examples and comparative examples in which the mold release layer was formed, the surface of the copper foil opposite to the side on which the mold release layer was formed was set as the first surface, and the copper foil with the mold release layer formed was the first surface. One surface is set as a second surface. In the examples and comparative examples in which the release layer was not formed, the surface on the S surface side of the electrolytic copper foil was set as the first surface, and the surface on the M surface side of the electrolytic copper foil was set as the second surface.

(1) Roughening

[Spherical roughening]

Spherical roughened particles were formed using a copper roughening plating bath described below composed of Cu, H ₂ SO ₄ , and As.

‧Liquid composition 1

CuSO ₄ ‧5H ₂ O 78 ~ 118g / L

Cu 20 ~ 30g / L

H ₂ SO ₄ 12g / L

Arsenic 1.0 ~ 3.0g / L

(Electric plating temperature 1) 25 ~ 33 ℃

(Current condition 1) Current density 78A / dm ² (above the limiting current density of the plating bath)

(Plating time 1) 1 ~ 45 seconds

Next, a copper electrolysis bath made of sulfuric acid-copper sulfate was used for covering plating to prevent the coarse particles from falling off and to improve the peeling strength. The covering plating conditions are described below.

‧Liquid composition 2

CuSO ₄ ‧5H ₂ O 156g / L

Cu 40g / L

H ₂ SO ₄ 120g / L

(Electrical plating temperature 2) 40 ° C

(Current condition 2) Current density: 20A / dm ² (less than the limiting current density of the plating bath)

(Plating time 2) 1 ~ 60 seconds

(2) Heat-resistant treatment (barrier treatment)

(Liquid composition)

Ni 13g / L

Zn 5g / L

pH 2

(Electroless plating conditions)

Temperature 40 ℃

Current density 8A / dm ²

(3) Anti-rust treatment

(Liquid composition)

CrO ₃ 2.5g / L

Zn 0.7g / L

Na ₂ SO ₄ 10g / L

pH 4.8

(Zinc Chromate Condition)

Temperature 54 ℃

Current density 0.7As / dm ²

(4) Silane coupling treatment

(Liquid composition)

Tetraethoxysilane content 0.4%

pH 7.5

Spraying of coating method solution

(5) Formation of a release layer

[Release layer A]

An aqueous solution of a silane compound (n-propyltrimethoxysilane: 4 wt%) was applied to the treated surface of the copper foil using a spray coater, and then the surface of the copper foil was dried in air at 100 ° C. for 5 minutes to form a release layer A. The stirring time of "dissolving the silane compound in water before coating" was set to 30 hours, the alcohol concentration in the aqueous solution was set to 10 vol%, and the pH of the aqueous solution was set to 3.8 to 4.2.

[Release layer B]

Using sodium 1-dodecanethiol sulfonate as a compound having 2 or less mercapto groups in the molecule, an aqueous solution of sodium 1-dodecylthiol sulfonate (sodium 1-dodecylthiol sulfonate concentration: 3 wt%) was applied to the treated surface of the copper foil, and then dried in air at 100 ° C. for 5 minutes to produce a release layer B. The pH of the aqueous solution is set to 5-9.

[Release layer C]

Using aluminum triisopropoxide of an aluminate compound as a metal alkoxide, an aqueous solution of aluminum triisopropoxide (triisopropoxy aluminum concentration: 0.04 mol / L) was applied to a copper foil using a spray coater. After the surface was treated, it was dried in air at 100 ° C for 5 minutes to prepare a release layer C. The stirring time of "dissolving the aluminate compound in water to before coating" was set to 2 hours, the alcohol concentration in the aqueous solution was set to 0 vol%, and the pH of the aqueous solution was set to 5 to 9.

[Release layer D]

Using a n-decyl-triisopropoxytitanium titanate compound as the metal alkoxide, an aqueous solution of n-decyl-triisopropoxytitanium (n-decyl-triisopropoxytitanium) was spray-coated using a spray coater. (Concentration: 0.01 mol / L) After being applied to the treated surface of the copper foil, it was dried in air at 100 ° C. for 5 minutes to prepare a release layer D. The stirring time of "dissolving the titanate compound in water to before coating" was set to 24 hours, the alcohol concentration in the aqueous solution was set to 20 vol% in methanol, and the pH of the aqueous solution was set to 5 to 9.

[Release layer E]

Using an n-propyl-tri-n-butoxy zirconium of a zirconate compound as the metal alkoxide, an aqueous solution of n-propyl-tri-n-butoxy zirconium (n-propyl-tri-n-butoxy zirconium) was spray-coated using a spray coater. (Concentration: 0.04 mol / L) After being applied to the treated surface of the copper foil, it was dried in air at 100 ° C. for 5 minutes to produce a release layer E. The stirring time of "dissolving the titanate compound in water to before coating" was set to 12 hours, the alcohol concentration in the aqueous solution was set to 0 vol%, and the pH of the aqueous solution was set to 5 to 9.

(6) Resin layer forming process

In Example 1, after the release layer was formed, a resin layer was further formed under the following conditions.

(Resin Synthesis Example)

To a 2-liter three-necked flask was added 117.68 g (400 mmol) of 3,4,3 ', 4'-biphenyltetracarboxylic dianhydride and 87.7 g (300 mmol) of 1,3-bis (3-aminophenoxy) benzene. , 4.0 g (40 mmol) of γ-valerolactone, 4.8 g (60 mmol) of pyridine, 300 g of N-methyl-2-pyrrolidone (hereinafter referred to as NMP), and 20 g of toluene, heated at 180 ° C for 1 hour, and then cooled to room temperature Nearby, then add 29.42 g (100 mmol) of 3,4,3 ', 4'-biphenyltetracarboxylic dianhydride, 82.12 g of 2,2-bis {4- (4-aminophenoxy) phenyl} propane (200 mmol), 200 g of NMP, 40 g of toluene, mixed at room temperature for 1 hour, and then heated at 180 ° C. for 3 hours to obtain a block copolymer polyimide having a solid content of 38%. The three-necked flask was stirred with an anchor made of stainless steel. A reflux cooler with a spherical cooling tube is installed on the separator of the rod, the nitrogen introduction tube and the stopcock. In this block copolymerized polyfluorene imine, the general formula (1) shown below: the general formula (2) = 3: 2, the number average molecular weight is 70,000, and the weight average molecular weight is 150,000.

The block copolymerized polyimide solution obtained in the synthesis example was further diluted with NMP to prepare a block copolymerized polyimide solution having a solid content of 10%. To this block copolymerized polyfluorene imide solution was added bis (4-maleimide phenylphenyl) methane (BMI-H, KI chemical conversion) to prepare a solid having a solid content weight ratio of 35 and the block copolymerized polyfluorene imide. A component weight ratio of 65 (that is, a bis (4-maleimidephenyl) methane solid component weight included in the resin solution: a block copolymerized polyimide solid component weight included in the resin solution = 35:65), Then, it was dissolved and mixed at 60 ° C for 20 minutes to prepare a resin solution. Then, the resin solution was coated on the release layer forming surface, and dried at 120 ° C for 3 minutes under a nitrogen atmosphere, and then dried at 160 ° C for 3 minutes, and finally heated at 300 ° C for 2 minutes. Copper foil for resin layer. The thickness of the resin layer was set to 2 μm.

(7) Various evaluations

‧Evaluation of the root mean square height Sq of both surfaces of the metal foil, and the ratio (Sq / Rsm) of the root mean square height Sq to the average interval Rsm of irregularities

The surface of each metal foil (the surface on the surface-treated side when surface-treated, such as roughening treatment, is the surface after the surface treatment, and when the mold-release layer is formed, it is the side on which the mold-release layer is provided. The surface root mean square height Sq and the ratio (Sq / Rsm) of the root mean square height Sq to the average interval Rsm of irregularities were measured using a laser microscope LEXT OLS4100 manufactured by Olympus Co., Ltd. In addition, Rsm is measured according to JIS B 0601 2001 standard mode, and Sq is measured according to ISO25178 standard mode. In addition, Rsm and Sq both set "the average value of Rsm and Sq values measured in arbitrary 10 portions" as the values of Rsm and Sq. The measurement length of Rsm is 258 μm, and the measurement area of Sq is 258 μm in length × 258 μm in width. Next, based on the obtained value, the ratio (Sq / Rsm) of the root mean square height Sq to the average interval Rsm of unevenness is calculated. The temperature at the time of measurement was 23 to 25 ° C.

‧Circuitability on metal foil

The laminated body 1 is manufactured on the surface (second surface) on the side of the release layer of the metal foil with a release layer or the second area layer of the metal foil. Then, the side of the metal foil with the release layer laminated to the resin substrate is the surface opposite to the side (first side), or the surface of the metal foil opposite to the resin substrate laminated side (the first side). The resist is applied, exposed and developed, and the resist is etched into a line shape. Then, a Cu-plated circuit with a thickness of 12 μm was formed, and then the resist was removed, thereby forming linear circuits (wirings) with 20 lines and gaps (L / S) of 12 μm / 12 μm and a length of 1 mm. Then, on the side of the metal foil with the release layer on the side where the circuit is formed, or the side of the metal foil on which the circuit is formed, the double-malay is laminated by thermocompression bonding to embed the circuit. Imine three Resin prepreg. Then, the resin substrate laminated on the release layer-side surface (second surface) of the metal foil with release layer or the second surface of the metal foil is peeled off, and then exposed by etching with ferric chloride. Remove the metal foil with release layer, or metal foil. In addition, the above etching is performed to the above circuit and the bismaleimide three around the circuit. The extent to which the resin prepreg is completely exposed. Next, the difference (μm) between the maximum value and the minimum value of the circuit width as viewed from the upper surface of the circuit was measured, and five locations were measured and set as the average value. If the difference between the maximum value and the minimum value is 2 μm or less, it is determined that the circuit has good circuit linearity, and is set to “◎◎”. When the difference between the maximum value and the minimum value exceeds 2 μm and is 3 μm or less, “◎” is set. When the difference between the maximum value and the minimum value exceeds 3 μm and is 4 μm or less, “○○” is set. When the difference between the maximum value and the minimum value exceeds 4 μm and is 5 μm or less, “○” is set. When the difference between the maximum value and the minimum value exceeds 5 μm, it is set to “×”.

‧Circuit peeling on metal foil;

The laminated body 1 is manufactured on the surface (second surface) on the side of the release layer of the metal foil with a release layer or the second area layer of the metal foil. Then, the side of the metal foil with the release layer laminated to the resin substrate is the side opposite to the side (first side), or the side of the metal foil laminated to the resin substrate is the side opposite to the side (first side) ) The resist is applied, exposed and developed, and the resist is etched into a line shape. Then, a Cu-plated circuit with a thickness of 12 μm was formed, and then the resist was removed, thereby forming linear circuits (wirings) with 20 lines and gaps (L / S) of 12 μm / 12 μm and a length of 1 mm. At this time, when the resist is removed, the number of times the circuit is peeled off from the surface of the metal foil with the release layer and the surface of the metal foil is counted. When the number of peelings of the circuit from the surface of the metal foil with the release layer and the surface of the metal foil during the 10 times of resist removal is 0, it is set to "◎◎", and when it is 1 out of 10 times, it is set to "◎", Set "○" when 2 to 3 times out of 10 times and "×" when 4 or more times out of 10 times.

‧Manufacturing of laminated body 2

The following resin substrates 1 to 3 are bonded to the surface (second surface) on the release layer side of each metal foil, or the second surface of the metal foil, respectively.

Substrate 1: GHPL-830 MBT manufactured by Mitsubishi Gas Chemical Co., Ltd.

Substrate 2: 679-FG manufactured by Hitachi Chemical Industries, Ltd.

Substrate 3: EI-6785TS-F manufactured by Sumitomo Bakelite Co., Ltd.

The temperature, pressure, and time for lamination pressurization are recommended by the manufacturer of each substrate.

‧Evaluation of peel strength

With respect to the laminated body 2, the conventional peel strength when the resin substrate was peeled from the copper foil using the tensile tester Autograph 100 was measured according to IPC-TM-650, and the peelability of the metal foil was evaluated according to the following criteria. The results are described in the "Peeling Strength" column in Table 1. The peeling strength is preferably 2 to 200 gf / cm.

○: A range of 2 to 200 gf / cm.

×: Less than 2 gf / cm or more than 200 gf / cm.

‧Evaluation of resin failure mode

The peeling surface of the resin substrate after peeling was observed with an electron microscope, and a failure mode of the resin (aggregation, interface, a mixture of aggregation and interface) was observed. Regarding the failure mode of the resin, "Interface" means peeling at the interface between the copper foil and the resin, "Cohesion" means that the peeling strength is too strong and the resin is broken, and "Mixed presence" means that the "Interface" and "Cohesion" are mixed. The failure mode of the resin is preferably an "interface".

‧Evaluation of circuit peeling and substrate bulge

On the peeling surfaces of the resin substrates 1 to 3 after the peeling, a copper plating pattern (line / line) was formed using a plating solution (a liquid composition of Cu: 50 g / L, H ₂ SO ₄ : 50 g / L, and Cl: 60 ppm). Gap = 40 μm / 40 μm) (Example 1). In addition, in Example 1, the peeling surfaces of the resin substrates 1 to 3 after the peeling were cleaned and electroless copper plating was performed before the copper plating pattern was formed, as in the semi-additive method. Then, the dry film was laminated on an electroless copper plating layer. Next, exposure and development are performed to etch the dry film into a linear shape, and the dry film at a predetermined portion where the copper plating pattern is formed is removed. Then, the above-mentioned copper plating pattern is formed on the electroless copper plating layer not covered by the dry film by electroplating. Next, after the copper plating pattern is formed, the dry film and the electroless copper plating layer in a portion where the copper plating pattern is not formed are removed. Further, a printed pattern (line / gap = 40 μm / 40 μm) was formed by ink jetting using an ink containing a conductive paste on the peeling surface of the resin substrate after the peeling (Example 2). Then, a resin layer (assuming a resin constituting a build-up layer) made of a liquid crystal polymer was laminated on the release surface of the resin substrate after the peeling (Example 3).

Then, it was confirmed by a reliability test (250 ° C. ± 10 ° C. × 1 hour heating test) whether circuit peeling or substrate bulging occurred. The size of the evaluation sample was 250 mm × 250 mm, and three samples were measured for each sample number.

A sample in which no circuit peeling and substrate bulging occurred was evaluated as "「 ". A small amount of circuit peeling or substrate bulging (three or less in one sample) was evaluated as "○" for a sample that could be used as a product as long as it was screened. In addition, a sample having multiple circuit peeling or substrate bumps (more than three in one sample) that could not be used as a product was evaluated as “×”.

The test conditions and evaluation results are shown in Table 1.

(Evaluation results)

Examples 1 to 19 are examples of metal foils having a root-mean-square height Sq of 0.01 to 1 μm on the first surface. Circuit formation on the metal foil is good, and circuit peeling on the metal foil can be suppressed well. In addition, Examples 1 to 18 are examples in which a release layer is provided on the second surface side, or Sq and / or Sq / Rsm of the second surface of the metal foil are controlled within a specified range, and the metal foil is removed from the resin The substrate has good releasability during physical peeling, and can effectively suppress the occurrence of circuit peeling and substrate bulge. Example 19 is an example in which a release layer was provided on the second surface side, and the peelability was good when the metal foil was physically peeled from the resin substrate.

In Comparative Examples 1 and 2, the root-mean-square height Sq of the first surface exceeded 1 μm, and the circuit formability on the metal foil was poor. In Comparative Example 3, the root mean square height Sq of the first surface was less than 0.01 μm, and the peeling of the circuit on the metal foil could not be sufficiently suppressed.

Claims (35)

A metal foil with a release layer includes: a metal foil having a first surface and a second surface, and the root mean square height Sq of the first surface is 0.01 μm or more and 1 μm or less, and the root mean square height Sq is The measurement area was an average value of Sq obtained by measuring 258 μm × width 258 μm in 10 arbitrary portions, and a release layer provided on the second surface of the metal foil. For example, the metal foil with a release layer according to item 1 of the patent application scope, wherein the root mean square height Sq of the second surface of the metal foil is 0.25 μm or more and 1.6 μm or less, and the root mean square height Sq is a measurement area. An average value of Sq obtained by measuring in a length of 258 μm × width of 258 μm in 10 arbitrary portions was set. For example, the metal foil with a release layer in item 1 of the patent application scope has a ratio (Sq / Rsm) of the root mean square height Sq of the second surface of the metal foil to the average interval Rsm of the unevenness of 0.03 or more and 0.40 or less. The surface unevenness, and the root mean square height Sq is an average value of Sq obtained by measuring the measurement area at a length of 258 μm × width of 258 μm in arbitrary 10 portions. For example, the metal foil with a release layer in item 2 of the patent application scope has a ratio (Sq / Rsm) of the root mean square height Sq of the second surface of the metal foil to the average interval Rsm of the unevenness of 0.03 or more and 0.40 or less. The surface unevenness, and the root mean square height Sq is an average value of Sq obtained by measuring the measurement area at a length of 258 μm × width of 258 μm in arbitrary 10 portions. For example, the metal foil with a release layer according to any one of the items 1 to 4 of the patent application scope satisfies any one or two of the following (5-1) and (5-2), (5-1) above The root-mean-square height Sq of the first surface satisfies any one or both of the following (5-1-1) and (5-1-2). The root-mean-square height Sq is a measurement area having a length of 258 μm × The average value of Sq obtained by measuring at a width of 258 μm in arbitrary 10 parts: (5-1-1) The root mean square height Sq of the first surface satisfies any one of the following, and the root mean square height Sq is determined by measuring The area is set to an average value of Sq obtained by measuring 258 μm × width 258 μm in arbitrary 10 parts:. 0.020μm or more; It is 0.025 μm or more; (5-1-2) The root-mean-square height Sq of the first surface satisfies any of the following, and the root-mean-square height Sq is a length of 258 μm × width 258 μm of the measurement area at an arbitrary 10 The average value of Sq measured in each part:. 0.90 μm or less; 0.32 μm or less; 0.25 μm or less; (5-2) The ratio (Sq / Rsm) of the root mean square height Sq of the second surface of the metal foil to the average interval Rsm of the unevenness satisfies any one or both of the following, the root mean square height Sq is the average value of Sq obtained by setting the measurement area to a length of 258 μm × width of 258 μm and measuring in any 10 parts:. More than 0.05; It is 0.24 or less. For example, the metal foil with a release layer according to any one of claims 1 to 4, wherein the thickness of the metal foil is 1 μm or more and 105 μm or less. For example, the metal foil with a release layer according to any one of claims 1 to 4 of the patent application scope, wherein the metal foil is a copper foil. For example, the metal foil with a release layer according to any one of claims 1 to 4, wherein a first surface of the metal foil and / or between the metal foil and the mold release layer is selected from roughening One or more layers in the group consisting of a treatment layer, a heat-resistant layer, a rust prevention layer, a chromate treatment layer, and a silane coupling treatment layer. For example, the metal foil with a release layer according to item 8 of the patent application scope, wherein the above-mentioned provided on the first surface of the metal foil is selected from a roughened layer, a heat-resistant layer, a rust-proof layer, a chromate-treated layer, and a silane One or more layers in the group consisting of the coupling treatment layers are provided with a resin layer. For example, the metal foil with a release layer according to item 9 of the application, wherein the resin layer is a resin, a primer, or a semi-hardened resin. For example, the metal foil with a release layer according to any one of claims 1 to 4, wherein the release layer includes at least one or two or more of the following compounds selected from the group consisting of the following chemical formulas Aluminate compounds, titanate compounds, zirconate compounds, hydrolysates of aluminate compounds, hydrolysates of titanate compounds, hydrolysates of zirconate compounds, condensation products of hydrolysates of aluminate compounds, In a group consisting of a condensate of a hydrolyzate of a titanate compound and a condensate of a zirconate compound, (R ¹ ) _m -M- (R ² ) _n (wherein R ¹ is an alkoxy group) Or a halogen atom, R ² is a hydrocarbon group selected from the group consisting of an alkyl group, a cycloalkyl group, and an aryl group, or a hydrocarbon group in which one or more hydrogen atoms of the above hydrocarbon group are replaced by a halogen atom, and M is Al, Ti, Zr In any of these, n is 0, 1, or 2, m is an integer from ¹ to M and the valence of M is at least one, and at least one of R ¹ is an alkoxy group; m + n is the valence of M; the valence of M In the case of Al, it is 3, and in the case of Ti and Zr, 4). For example, the metal foil with a release layer according to any one of claims 1 to 4, wherein the release layer includes at least one or two or more of the following compounds selected from the group consisting of the following chemical formulas In the group consisting of a silane compound, a hydrolysis product of the above-mentioned silane compound, and a condensation product of the above-mentioned hydrolysis product, (In the formula, R ¹ is an alkoxy group or a halogen atom, and R ² is a hydrocarbon group selected from the group consisting of an alkyl group, a cycloalkyl group, and an aryl group, or one or more hydrogen atoms of the above hydrocarbon group are replaced by a halogen atom. R ³ and R ⁴ are each independently a halogen atom, an alkoxy group, one or more of the above-mentioned hydrocarbon group or one or more hydrogen atoms of the above-mentioned hydrocarbon group selected from the group consisting of an alkyl group, a cycloalkyl group, and an aryl group are halogen atoms. Substituted hydrocarbyl). For example, the metal foil with a release layer according to any one of claims 1 to 4 of the application, wherein the release layer is formed by using a compound having two or less mercapto groups in the molecule. For example, the metal foil with a release layer according to any one of claims 1 to 4, wherein a resin layer is provided on the surface of the release layer. For example, the metal foil with a release layer according to item 14 of the application, wherein the resin layer is a resin, a primer, or a semi-hardened resin. A metal foil having a first surface and a second surface, and the root mean square height Sq of the first surface is 0.01 μm or more and 1 μm or less, and the root mean square height Sq is a measurement area having a length of 258 μm × width 258 μm And the average value of Sq obtained by measurement in arbitrary 10 parts was measured. For example, the metal foil of the 16th area of the patent application, wherein the root mean square height Sq of the second surface is 0.25 μm or more and 1.6 μm or less, and the root mean square height Sq is a measurement area having a length of 258 μm × width 258 μm and The average value of Sq obtained by measurement was measured in 10 arbitrary portions. For example, the metal foil of the 16th area of the application for a patent has a surface asperity having a ratio (Sq / Rsm) of the root mean square height Sq of the second surface of the metal foil to the average interval Rsm of asperities of 0.03 to 0.40. The root-mean-square height Sq is an average value of Sq obtained by measuring the measurement area at a length of 258 μm × width of 258 μm in 10 arbitrary portions. For example, the metal foil of claim 17 has a surface asperity having a ratio (Sq / Rsm) of the root mean square height Sq of the second surface of the metal foil to the average interval Rsm of asperities of 0.03 to 0.40. The root-mean-square height Sq is an average value of Sq obtained by measuring the measurement area at a length of 258 μm × width of 258 μm in 10 arbitrary portions. If the metal foil of any one of the 16th to 19th of the scope of patent application, it satisfies any one or two of the following (20-1) and (20-2), (20-1) The root-mean-square height Sq satisfies any one or both of the following (20-1-1) and (20-1-2). The above-mentioned root-mean-square height Sq is a measurement area having a length of 258 μm × width of 258 μm and The average value of Sq measured by arbitrary 10 parts: (20-1-1) The root-mean-square height Sq of the first surface satisfies any of the following, and the root-mean-square height Sq is the length of the measurement area. 258 μm × width 258 μm and the average value of Sq measured in arbitrary 10 parts:. 0.020μm or more; (20-1-2) The root-mean-square height Sq of the first surface satisfies any of the following, and the root-mean-square height Sq is a measurement area having a length of 258 μm × width of 258 μm and an arbitrary value of 10 The average value of Sq measured in each part:. 0.90 μm or less; 0.32 μm or less; 0.25 μm or less; (20-2) The ratio (Sq / Rsm) of the root mean square height Sq of the second surface of the metal foil to the average interval Rsm of the unevenness satisfies any one or both of the following, the root mean square height Sq is the average value of Sq obtained by setting the measurement area to a length of 258 μm × width of 258 μm and measuring in any 10 parts:. More than 0.05; It is 0.24 or less. For example, the metal foil according to any one of claims 16 to 19, wherein the thickness of the metal foil is 1 μm or more and 105 μm or less. For example, the metal foil according to any one of claims 16 to 19, wherein the metal foil is a copper foil. For example, the metal foil according to any one of claims 16 to 19, wherein the first surface of the metal foil and / or the second surface of the metal foil is selected from a roughened layer, a heat-resistant layer, One or more layers in the group consisting of a rust layer, a chromate-treated layer, and a silane coupling-treated layer. For example, the metal foil of the 23rd scope of the patent application, wherein the above-mentioned provided on the first surface of the metal foil is selected from the group consisting of a roughened layer, a heat-resistant layer, a rust-proof layer, a chromate-treated layer, and a silane coupling-treated layer. One or more layers in the composed group are provided with a resin layer. A laminated body comprising a metal foil with a release layer according to any one of the patent applications 1 to 15 or a metal foil with any of the patent applications 16 to 24 and the above-mentioned release layer A metal foil or a resin substrate for the metal foil. For example, the laminated body according to item 25 of the application, wherein the resin substrate is a prepreg or contains a thermosetting resin. A printed wiring board comprising the above-mentioned metal foil with a release layer according to any one of claims 1 to 15 or a metal foil according to any of claims 16 to 24. A semiconductor package includes a printed wiring board with a scope of application for item 27. An electronic device includes a printed wiring board with a patent scope of 27 or a semiconductor package with a patent scope of 28. A method for manufacturing a printed wiring board, which comprises the following steps: a metal foil with a release layer in any one of the scope of patent applications 1 to 15 or a metal foil sticker in any of the scope of patent applications 16 to 24 Insulating substrate; the metal foil with release layer or the metal foil is peeled from the insulating substrate without being etched to obtain the metal foil with release layer or the metal foil transferred on the peeling surface An insulating substrate having a surface profile; and forming a circuit on the peeling surface side of the insulating substrate to which the surface profile is transferred. According to the method for manufacturing a printed wiring board according to claim 30, the circuit formed on the peeling surface side of the insulating substrate to which the surface contour is transferred is a plating pattern or a printed pattern. A method for manufacturing a printed wiring board, which comprises the following steps: a metal foil with a release layer in any one of the scope of patent applications 1 to 15 or a metal foil sticker in any of the scope of patent applications 16 to 24 Insulating substrate; the metal foil with release layer or the metal foil is peeled from the insulating substrate without being etched to obtain the metal foil with release layer or the metal foil transferred on the peeling surface An insulating substrate having a surface contour; and an additional layer is provided on the peeling surface side of the insulating substrate to which the surface contour is transferred. For example, the manufacturing method of a printed wiring board according to item 32 of the application, wherein the resin constituting the build-up layer includes a liquid crystal polymer, a fluororesin, a low dielectric constant polyfluorene imide, a polyphenylene ether, a cycloolefin polymer, or a Tetrafluoroethylene. A method for manufacturing a printed wiring board, comprising the following steps: a metal foil with a release layer in any one of the scope of patent applications 1 to 15 or a metal foil in any of the scope of patent applications 16 to 24, The insulating substrate 1 is bonded from the release layer side or the second surface side of the metal foil; the circuit is formed on the first surface side of the metal foil with the release layer or the metal foil laminated with the insulating substrate 1; Covering the circuit with the insulating substrate 2 and burying the circuit in the insulating substrate 2; peeling the insulating substrate 1 from the metal foil with the release layer or the metal foil to expose the metal foil with the release layer or the metal foil; And removing the exposed metal foil with a release layer or the metal foil. A method for manufacturing a printed wiring board, comprising the following steps: a metal foil with a release layer in any one of the scope of patent applications 1 to 15 or a metal foil in any of the scope of patent applications 16 to 24, The insulating substrate 1 is bonded from the release layer side or the second surface side of the metal foil; a dry film is laminated on the first surface side of the metal foil with a release layer laminated on the insulating substrate 1 or the metal foil; After the dry film is patterned, a circuit is formed; the dry film is peeled to expose the circuit; the circuit is buried in the insulating substrate 2 by covering the exposed circuit with an insulating substrate 2; The foil or the metal foil peels the insulating substrate 1 to expose the metal foil or the metal foil with a release layer; and removes the metal foil or the metal foil with the release layer that is exposed.