JPWO2020144861A1 - Manufacturing method of metal-clad laminate, metal-clad laminate, printed wiring board and semiconductor package, coreless substrate forming support and semiconductor rewiring layer forming support - Google Patents

Abstract

Provided are a metal-clad laminated board having excellent plate thickness accuracy and a method for manufacturing the same. Further, the present invention provides a printed wiring board in which a circuit is formed on the metal-clad laminated board, and a semiconductor package in which a semiconductor element is mounted on the printed wiring board. Further, a support for forming a coreless substrate and a support for forming a semiconductor rewiring layer, which include the metal-clad laminate, are provided. Specific examples of the method for manufacturing the metal-clad laminate include (1) a step of polishing at least one surface of a cured product of a prepreg containing a thermosetting resin composition and a base material, and (2). -1) The step of laminating a metal foil on the surface polished in the step (1) to form a metal-clad laminate, or (2-2) the metal foil and heat on the surface polished in the step (1). Metal-clad, comprising a step of laminating a curable resin film or a thermosetting resin film with a metal foil so that the thermocurable resin film is on the polished surface side to form a metal-clad laminate. This is a method for manufacturing a laminated board.

Description

The present invention relates to a method for manufacturing a metal-clad laminate, a metal-clad laminate, a printed wiring board and a semiconductor package, and a support for forming a coreless substrate and a support for forming a semiconductor rewiring layer.

In recent years, with the increasing density of electronic devices, miniaturization, weight reduction, and multifunctionality have further progressed, and along with this, the density of printed wiring boards and semiconductor packages for mounting LSI (Large Scale Integration) have also increased. High reliability is required. As a result, the demand for improving the plate thickness accuracy of metal-clad laminates is becoming stricter.
A metal-clad laminate obtained by sandwiching a plurality of prepregs between metal foils and laminating by press molding or the like is used as a core substrate of a printed wiring board (see, for example, paragraph [0057] of Patent Document 1). Surface waviness occurs after press molding due to the influence of the base material such as glass cloth existing in. In the past, this level of surface waviness was acceptable, but there is a tendency to achieve a higher level of plate thickness accuracy for metal-clad laminates in order to further increase the density and ensure high reliability. It has become necessary to solve the problem of deterioration of plate thickness accuracy due to the surface waviness.
Further, the plate thickness accuracy tends to depend on the fluidity of the resin composition, and as shown in FIG. 7, a metal-clad laminated plate obtained by laminating molding such as press molding (before being cut to a predetermined size). The resin composition layer at the end of the so-called press panel) is usually thin, and from the viewpoint of plate thickness accuracy, the thinned portion of the resin composition layer has to be discarded. On the other hand, a method of highly filling an inorganic filler in order to reduce the fluidity of the resin composition is known, but the effect of improving the plate thickness accuracy is limited and the inorganic filler is highly filled. If is essential, there is a problem that the workability such as drill workability is significantly reduced.

Japanese Unexamined Patent Publication No. 2016-056371

Therefore, an object of the present invention is to provide a metal-clad laminated board having excellent plate thickness accuracy and a method for manufacturing the same. Further, an object of the present invention is a printed wiring board formed by forming a circuit on the metal-clad laminate, a semiconductor package in which a semiconductor element is mounted on the printed wiring board, and a coreless substrate including the metal-clad laminate. It is an object of the present invention to provide a support for forming and a support for forming a semiconductor rewiring layer.

As a result of diligent research to solve the above problems, the present inventors have obtained at least one of the cured products of the prepreg obtained by a method such as etching and removing the metal foil of the metal-clad laminate obtained by press molding. It has been found that the above-mentioned problems can be solved by polishing the surface of the above-mentioned surface, and the present invention has been completed. The present invention has been completed based on such findings.

The present invention relates to the following [1] to [15].
[1] (1) A step of polishing at least one surface of a cured product of a prepreg containing a thermosetting resin composition and a base material.
(2-1) A step of laminating a metal foil on a surface polished in the step (1) to form a metal-clad laminate.
A method for manufacturing a metal-clad laminated board.
[2] (1) A step of polishing at least one surface of a cured product of a prepreg containing a thermosetting resin composition and a base material.
(2-2) A metal foil and a thermosetting resin film or a thermosetting resin film with a metal foil are placed on the surface polished in the step (1), and the surface side on which the thermosetting resin film is polished is used. The process of forming a metal-clad laminated board by laminating so as to
A method for manufacturing a metal-clad laminated board.
[3] The method for manufacturing a metal-clad laminate according to the above [1] or [2], wherein in the step (1), both sides of the cured product of the prepreg are polished.
[4] The method for producing a metal-clad laminate according to any one of [1] to [3] above, wherein the thickness of the cured product of the prepreg is substantially made uniform by polishing in the step (1).
[5] Any of the above [1] to [4], wherein the cured product of the prepreg is obtained by etching and removing the metal foil of the metal-clad laminate whose surface of the cured product inside is not polished. A method for manufacturing a metal-clad laminate described in Crab.
[6] The size of the surface having the largest area of the cured product of the prepreg is 200 mm to 1,300 mm in length × 200 mm to 1,300 mm in width, and within 70 mm from the end of the cured product of the prepreg. The method for manufacturing a metal-clad laminate according to any one of [1] to [5] above, wherein at least a part of the thickness is thinner than the thickness of the central portion of the cured product.
[7] The production of the metal-clad laminate according to any one of [1] to [6] above, wherein in the step (1), the entire surface is polished until the thickness of the thinnest portion of the cured product of the prepreg is aligned. Method.
[8] In the step (1), (i) CMP (Chemical mechanical polishing) method, (ii) mechanical polishing such as fly cut, grind, sand blast, belt polishing, scrub polishing, (iii) persulfate, peroxidation. The method for producing a metal-clad laminate according to any one of the above [1] to [7], which is polished by a method selected from the group consisting of a hydrogen-sulfuric acid mixture, chemical polishing using an inorganic acid, an organic acid, or the like. ..
[9] The method for manufacturing a metal-clad laminate according to any one of the above [1] to [8], wherein the difference between the maximum value and the minimum value of the thickness of the obtained metal-clad laminate is 20 μm or less.
[10] A metal-clad laminate obtained by the manufacturing method according to any one of the above [1] to [9].
[11] (a) A cured product of a prepreg containing a thermosetting resin composition and a base material, which comprises a cured product in which at least one surface of the cured product is polished, and (b) a base material. A metal-clad laminate containing no thermosetting resin composition layer, and (c) metal foil.
[12] A printed wiring board containing the metal-clad laminate according to the above [10] or [11].
[13] A semiconductor package in which a semiconductor element is mounted on the printed wiring board according to the above [12].
[14] A support for forming a coreless substrate, which comprises the metal-clad laminate according to the above [10] or [11].
[15] A support for forming a semiconductor rewiring layer, comprising the metal-clad laminate according to the above [10] or [11].

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a metal-clad laminated board having excellent plate thickness accuracy and a method for manufacturing the same. Further, a printed wiring board formed by forming a circuit on the metal-clad laminate, a semiconductor package in which a semiconductor element is mounted on the printed wiring board, a support for forming a coreless substrate including the metal-clad laminate, and a support for forming the coreless substrate. A support for forming a semiconductor rewiring layer can be provided.
According to the method of the present invention, a metal-clad laminate having excellent plate thickness accuracy can be obtained without high filling with an inorganic filler, so that a metal-clad laminate with good workability can be obtained.

It is a conceptual diagram which shows an example of embodiment of the manufacturing method of this invention. It is a conceptual diagram which shows an example of embodiment of the manufacturing method of this invention. It is a conceptual diagram which shows an example of the manufacturing process of the coreless substrate using the support for forming a coreless substrate of this invention. The figure which shows the result of having measured the surface roughness (Ra) of the surface of the laminated body before polishing used in Example 1 using the high-precision three-dimensional surface shape roughness measurement system (Wyko NT9100 manufactured by Veeco Instruments). Is. The surface roughness (Ra) of the surface of the cured prepreg after polishing obtained in Example 1 was measured using a high-precision three-dimensional surface shape roughness measurement system (Wyko NT9100, manufactured by Veeco Instruments). It is a figure which shows. 6 is a digital microscope image of a cross section of the copper-clad laminate A obtained in Example 1. It is a conceptual diagram which shows the appearance that the thickness of the end portion of a resin composition layer becomes thin when the metal-clad laminated board (press panel) is manufactured by press molding.

In the numerical range described in the present specification, the upper limit value or the lower limit value of the numerical range may be replaced with the value shown in the examples. Further, the lower limit value and the upper limit value of the numerical range are arbitrarily combined with the lower limit value or the upper limit value of another numerical range.
Further, as for each component and material exemplified in this specification, one kind may be used alone or two or more kinds may be used in combination unless otherwise specified.
The present invention also includes aspects in which the items described in the present specification are arbitrarily combined.

[Manufacturing method of metal-clad laminate]
One aspect of the method for manufacturing a metal-clad laminate of the present invention is
(1) A step of polishing at least one surface of a cured product of a prepreg containing a thermosetting resin composition and a base material [hereinafter, may be referred to as step (1)].
(2-1) A step of laminating a metal foil on a surface polished in the step (1) to form a metal-clad laminate [hereinafter, may be referred to as step (2-1)].
It is a method of manufacturing a metal-clad laminated board having.

Further, another aspect of the method for manufacturing a metal-clad laminate of the present invention is as follows.
(1) A step of polishing at least one surface of a cured product of a prepreg containing a thermosetting resin composition and a base material.
(2-2) A metal foil and a thermosetting resin film or a thermosetting resin film with a metal foil are placed on the surface polished in the step (1), and the surface side on which the thermosetting resin film is polished is used. Step of forming a metal-clad laminate by laminating so as to be [hereinafter, may be referred to as step (2-2)],
It is a method of manufacturing a metal-clad laminated board having.
Hereinafter, the steps (1) will be described in detail in order from the above step (1) with reference to FIG. 1 or FIG. 2 as necessary.

<Process (1)>
The step (1) is a step of polishing at least one surface of the cured product 1 of the prepreg containing the thermosetting resin composition 6 and the base material 7. Here, in the present invention, the cured product of the prepreg refers to a state in which the thermosetting resin composition contained in the prepreg is C-staged, and the thermosetting resin composition is in a B-staged state. Things are not included. Further, "at least one surface of the cured product 1 of the prepreg" means at least one surface of the two surfaces having the largest area in the cured product 1 of the prepreg, and is a surface in the thickness direction (horizontal surface). Is not included. However, it does not deny that the surface (horizontal surface) in the thickness direction is polished in addition to "at least one surface of the cured product 1 of the prepreg".
The cured product 1 of the prepreg used in the step (1) can be obtained by etching and removing the metal foil of the metal-clad laminate whose surface of the cured product inside is not polished. In other words, the metal-clad laminate obtained by arranging metal foils on one or both sides of one or more prepregs and laminating such as press molding has surface waviness, and the plate thickness accuracy is not sufficient. Therefore, by etching and removing the metal foil from the metal-clad laminate and going through the step (1), the surface waviness is eliminated, which in turn leads to the formation of a metal-clad laminate having high plate thickness accuracy.
Here, the surface waviness is an undulation that is repeated at intervals larger than the surface roughness. In the present invention, as shown in FIG. 4, which is surface-observed under the conditions described in Examples using a high-precision three-dimensional surface shape roughness measurement system, a wide range of X-axis: 95 μm and Y-axis: 95 μm (however, however). The place is arbitrary.) When the surface roughness (arithmetic average roughness: Ra) has a place where the surface roughness is 1.0 μm or less and a place where the surface roughness is more than 1.0 μm, it is said that the surface waviness is large. The plate thickness accuracy is low. It can be said that the larger the surface roughness of the portion where the surface roughness (Ra) exceeds 1.0 μm (for example, 1.5 μm or more, 2.0 μm or more, etc.), the larger the surface waviness. Since the surface waviness is eliminated in the present invention, when the surface roughness is observed using the high-precision three-dimensional surface shape roughness measurement system, the surface roughness is 1.0 μm or less in the entire surface range of the cured product of the prepreg. It is preferably 0.9 μm or less, and more preferably 0.8 μm or less.

There is no particular limitation on the method of etching and removing the metal foil of the metal-clad laminate whose surface of the hardened material inside is not polished, and the usual etching removal method of the metal foil of the metal-clad laminate used for manufacturing the printed wiring board. Can be adopted. For example, the metal foil can be removed by etching using ferric chloride solution, ammonium persulfate, or the like.
As the metal-clad laminate whose surface of the cured product inside is not polished, a commercially available metal-clad laminate can be used, and it can also be manufactured by a known method. As a method for producing, for example, a metal foil is placed on one side or both sides of one or a plurality of (for example, 2 to 20) prepregs containing a thermosetting resin composition and a base material. A cured product obtained by laminating molding can also be used. The thermosetting resin composition and the base material will be described later. The laminating molding conditions are not particularly limited, but for example, using a multi-stage press, a multi-stage vacuum press, continuous molding, an autoclave molding machine, etc., the temperature is 100 to 250 ° C., the pressure is 0.2 to 10 MPa, and the pressure is 0.2 to 10 MPa. Conditions include a heating time of 0.1 to 5 hours.

Examples of the metal foil of the metal-clad laminate in which the surface of the cured product inside is not polished include copper foil, nickel foil, aluminum foil, and the like, and among these, copper foil is preferable. The thickness of the metal foil is not particularly limited, but for example, 0.5 to 150 μm is preferable, 1 to 100 μm is more preferable, 5 to 50 μm is further preferable, 5 to 30 μm is particularly preferable, and 7 to 18 μm is most preferable.

The surface 2 to be polished may be at least one surface of the cured product, but it is preferable to polish both sides of the cured product from the viewpoint of sufficiently eliminating surface waviness and increasing the plate thickness accuracy. Here, the "at least one surface of the cured product" means at least one surface of the two surfaces having the largest area in the cured product, and does not include a surface in the thickness direction (horizontal surface). Further, "both sides of the cured product" means two surfaces having the largest area in the cured product, and does not include a surface (horizontal surface) in the thickness direction. However, it does not deny that the surface (horizontal surface) in the thickness direction is polished in addition to "both sides of the cured product".
From the viewpoint of sufficiently eliminating surface waviness and increasing the plate thickness accuracy, it is preferable to polish the entire surface to be polished.
The size of the cured product 1 of the prepreg is not particularly limited, but the size of the metal-clad laminate (that is, the so-called press panel before being cut to a predetermined size) obtained by press molding has the largest area. It is more preferable that the size is 200 mm to 1,300 mm in length × 200 mm to 1,300 mm in width. Further, in the cured product of the prepreg, for example, at least a part of the thickness in the range within 70 mm (or within 50 mm from the end) of the cured product of the prepreg is the thickness of the central portion 3 of the cured product. It can be used even if there is a portion 4 thinner than that of the above. Here, the above-mentioned "range within 70 mm from the end of the cured product of the prepreg" is when measured from any end of the cured product of the prepreg toward the inside of the cured product and perpendicular to the end. It means that the range is within 70 mm.

There is no particular limitation on the method of polishing the surface of the cured product, but (i) CMP (Chemical mechanical polishing) method, (ii) mechanical polishing such as fly cut, grind, sand blast, belt polishing, scrub polishing, (iii) excessive. It is preferable to polish by a method selected from the group consisting of a sulfate, a hydrogen peroxide-sulfuric acid mixture, a chemical polishing using an inorganic acid, an organic acid and the like. Among these, polishing by the CMP method, fly cut, and grind is more preferable. As the polishing method, one type may be used alone, or two or more types may be used in combination.
By polishing, the surface waviness of the surface of the polished cured product is reduced, and the surface roughness (Ra) of the surface is preferably 1.0 μm or less, more preferably 0.9 μm or less, still more preferably 0.8 μm or less. Become. In the present invention, the surface roughness (Ra) can be measured by using a stylus type surface shape measuring instrument (manufactured by Bruker Corporation, trade name "DectakXT").
The CMP method is mechanical polishing accompanied by a chemical etching action with an alkaline polishing solution. When the CMP method is used, it is not particularly limited, but for example, "Maro Ota, 2 outsiders," Optical end point detection monitor for oxide film CMP ", [online], Ebara Time Signal, No. 207. (2005-4), [Search on June 12, 2018], Internet, <URL: https://www.ebara.co.jp/about/technologies/abstract/detail/__icsFiles/afieldfile/2016/04/ The CMP device described in "25 / 207_P25.pdf>" can be used. Further, as the mechanical polishing, for example, fly cutting is not particularly limited, but a grinding device using a diamond bite, for example, an automatic surface planar (manufactured by DISCO Co., Ltd., trade name "DAS8930") compatible with a 300 mm wafer, and the like. This is a method of physically grinding (polishing) using a grinder (manufactured by DISCO Co., Ltd., trade names "DFG8540" and "DFG8560") and the like.

By the step (1), the surface waviness of the cured product of the prepreg can be eliminated and the plate thickness accuracy can be improved. It can be said that the cured product has a substantially uniform thickness. Here, the substantially uniformization includes not only a mode in which the thickness is completely uniform, but also a mode in which the thickness is uniform to the extent that the surface waviness is within the above-mentioned range, even if it is not perfect.
Further, as shown in FIGS. 1 and 2, it is preferable that the polishing is performed on the entire surface until the thickness of the thinnest portion 5 in the cured product of the prepreg is aligned. Here, "equal to the thickness of the thinnest portion 5 in the cured product of the prepreg" means that the thickness of the entire prepreg is uniform to the extent that it is substantially uniform. By polishing in this way, the thickness of the entire cured product is substantially made uniform, so that it is not necessary to discard the portion where the thickness of the cured product has been reduced. At the time of polishing, there is no particular problem even if the base material in the prepreg is polished, but the base material may be polished while being adjusted to the extent that the base material is not polished.

(Thermosetting resin composition)
The thermosetting resin composition contained in the prepreg is not particularly limited as long as it contains a thermosetting resin. Examples of the thermosetting resin include epoxy resin, phenol resin, unsaturated imide resin, cyanate resin, isocyanate resin, benzoxazine resin, oxetane resin, unsaturated polyester resin, allyl resin, dicyclopentadiene resin, silicone resin, and modification. Examples thereof include silicone resin, triazine resin, melamine resin, urea resin, furan resin and the like. Further, without being particularly limited to these, known thermosetting resins can be used. These may be used alone or in combination of two or more. Among these, epoxy resin, unsaturated imide resin, and modified silicone resin are preferable.

The epoxy resin is not particularly limited, but is, for example, a bisphenol type epoxy resin such as a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, or a bisphenol S type epoxy resin; an alicyclic epoxy resin; an aliphatic chain. Epoxy resin; Novolak type epoxy resin such as phenol novolac type epoxy resin, cresol novolak type epoxy resin, bisphenol A novolak type epoxy resin, bisphenol F novolak type epoxy resin; phenol aralkyl type epoxy resin; stillben type epoxy resin; dicyclopentadiene Type epoxy resin; naphthalen skeleton-containing epoxy resin such as naphthol novolac type epoxy resin and naphthol aralkyl type epoxy resin; biphenyl type epoxy resin; biphenyl aralkyl type epoxy resin; xylylene type epoxy resin; dihydroanthracene type epoxy resin and the like. From these, a naphthalene skeleton-containing epoxy resin may be selected, or a naphthol aralkyl type epoxy resin may be selected.

Examples of the unsaturated imide resin include a maleimide resin, an addition reaction product of a maleimide resin and a monoamine compound, and a reaction product of a maleimide resin, a monoamine compound, and a diamine compound. The maleimide compound is not particularly limited, and is, for example, bis (4-maleimidephenyl) methane, polyphenylmethane maleimide, bis (4-maleimidephenyl) ether, 3,3'-dimethyl-5,5. '-Diethyl-4,4'-diphenylmethanebismaleimide, 4-methyl-1,3-phenylenebismaleimide, m-phenylenebismaleimide, bis (4-maleimidephenyl) sulfone, bis (4-maleimidephenyl) sulfide, bis (4-Maleimidephenyl) ketone, 2,2-bis (4- (4-maleimidephenoxy) phenyl) propane, bis (4- (4-maleimidephenoxy) phenyl) sulfone, 4,4'-bis (3-maleimide) Phenoxy) biphenyl, 1,6-bismaleimide- (2,2,4-trimethyl) hexane and the like. From these, bis (4-maleimidephenyl) methane may be selected.
As the monoamine compound, a monoamine compound having an acidic substituent (for example, a hydroxyl group, a carboxy group, etc.) is preferable, and specifically, o-aminophenol, m-aminophenol, p-aminophenol, o-aminobenzoic acid. , M-aminobenzoic acid, p-aminobenzoic acid, o-aminobenzenesulfonic acid, m-aminobenzenesulfonic acid, p-aminobenzenesulfonic acid, 3,5-dihydroxyaniline, 3,5-dicarboxyaniline, etc. Can be mentioned.
As the diamine compound, a diamine compound having at least two benzene rings is preferable, and a diamine compound having at least two benzene rings linearly between two amino groups is more preferable, and 4,4'-diamino. Diphenylmethane, 4,4'-diamino-3,3'-dimethyl-diphenylmethane, 4,4'-diamino-3,3'-diethyl-diphenylmethane, 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylsulfone , 3,3'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl ketone and the like.
As the unsaturated imide resin, for example, the maleimide compound described in JP-A-2018-165340 can also be used.

In addition to the thermosetting resin, the thermosetting resin composition includes a curing agent, a curing accelerator, an inorganic filler, an organic filler, a coupling agent, a leveling agent, an antioxidant, and a flame retardant, if necessary. , A mode containing at least one selected from a flame retardant aid, a rocking modification imparting agent, a thickening agent, a thixophilic imparting agent, a flexible material, a surfactant, a photopolymerization initiator and the like is preferable. In particular, with respect to the inorganic filler, in the present invention, the plate thickness accuracy can be improved without high filling, so that the content of the inorganic filler can be, for example, 10 to 60% by volume, and 20 to 20 to 60% by volume. It may be 60% by volume, 30 to 60% by volume, and the upper limit may be 57% by volume or 55% by volume in the numerical range. However, when it is necessary to highly fill the inorganic filler, in the present invention, it is not always denied that the content of the inorganic filler exceeds 60% by volume, for example, the upper limit of the numerical range of the content. The value may be 70% by volume or 80% by volume.

［式（１）中、複数のＲ^１は、それぞれ独立にアルキル基、フェニル基又は置換フェニル基を示し、互いに同じでも異なっていてもよく、複数のＲ^２は、それぞれ独立にアルキル基、フェニル基又は置換フェニル基を示し、互いに同じでも異なっていてもよく、Ｒ^３及びＲ^４はそれぞれ独立にアルキル基、フェニル基又は置換フェニル基を示し、Ｒ^５及びＲ^６はそれぞれ独立に２価の有機基を示す。ｎは２〜５０の整数を示す。]

［式（２）中、Ｒ^７は複数ある場合は各々独立に、水酸基、カルボキシル基又はスルホン酸基を示し、Ｒ^８は複数ある場合は各々独立に水素原子、炭素数１〜５の脂肪族炭化水素基、ハロゲン原子を示す。ｘは１〜５の整数、ｙは０〜４の整数であり、ｘ＋ｙ＝５である。］Further, for example, a modified silicone compound (modified silicone resin) described in International Publication No. 2012/099133, and if necessary, other thermosetting resins, curing agents, curing accelerators, inorganic fillers, heat. Thermosetting containing at least one selected from the group consisting of plastic resins, elastomers, organic fillers, flame retardants, ultraviolet absorbers, antioxidants, photopolymerization initiators, fluorescent whitening agents, adhesion improvers and the like. A sex resin composition or the like can also be used.
As the modified silicone compound, both terminal amino-modified silicone compounds are preferable, specifically, (A) siloxane diamine represented by the following general formula (1), and (B) at least two N-substituted maleimides in the molecular structure. A maleimide compound having a group, (C) a two-terminal amino-modified silicone compound obtained by reacting an amine compound having an acidic substituent represented by the following general formula (2), the details of which are described in International Publication No. 2012/099133. It's a street.

Wherein (1), a plurality of R ¹ each independently represent an alkyl group, a phenyl group or substituted phenyl group, may be the same or different from each other, a plurality of R ² each independently represent an alkyl group, a phenyl It represents a group or a substituted phenyl group and may be the same or different from each other, R ³ and R ⁴ independently represent an alkyl group, a phenyl group or a substituted phenyl group, respectively, and R ^{5 and R 6} are independently divalent. Indicates an organic group. n represents an integer of 2 to 50. ]

[In the formula (2), ^{when there are a plurality of R 7,} each independently indicates a hydroxyl group, a carboxyl group or a sulfonic acid group, and ^{when there are a plurality of R 8,} each independently has a hydrogen atom and an aliphatic group having 1 to 5 carbon atoms. Indicates a hydrocarbon group and a halogen atom. x is an integer of 1 to 5, y is an integer of 0 to 4, and x + y = 5. ]

(Base material)
As the base material contained in the prepreg, a sheet-shaped reinforcing base material is used, and well-known materials used for various laminated plates for electrical insulating materials can be used. Examples of the material of the base material include natural fibers such as paper and cotton linter; inorganic fibers such as glass fiber and asbestos; organic fibers such as aramid, polyimide, polyvinyl alcohol, polyester, tetrafluoroethylene and acrylic; and a mixture thereof. Be done. Among these, glass fiber is preferable from the viewpoint of flame retardancy. Examples of the glass fiber base material include woven fabrics using E glass, C glass, D glass, S glass, etc., or glass woven fabrics in which short fibers are bonded with an organic binder; a mixture of glass fibers and cellulose fibers. Be done. More preferably, it is a glass woven fabric using E glass.
These substrates have the shape of, for example, woven fabrics, non-woven fabrics, robinks, chopped strand mats or surfaced mats. The material and shape are selected according to the intended use and performance of the molded product, and one type may be used alone, or two or more types of materials and shapes may be combined as needed.
The thickness of the base material may be, for example, 0.01 to 0.5 mm, preferably 0.015 to 0.2 mm, preferably 0.02 to 0, from the viewpoint of formability and enabling high-density wiring. .15 mm is more preferred. From the viewpoint of heat resistance, moisture resistance, processability, etc., these base materials are preferably surface-treated with a silane coupling agent or the like, mechanically opened, or the like.

(Prepreg)
By impregnating the base material with the thermosetting resin composition and then heat-treating the substrate, a prepreg obtained by B-staged the thermosetting resin composition can be obtained. From the viewpoint of handleability and tackiness of the prepreg, the prepreg is preferably used in a cooling step for cooling the prepreg. The prepreg may be cooled by natural cooling, or may be cooled by using a cooling device such as a blower or a cooling roll. The temperature of the prepreg after cooling is usually 5 to 80 ° C, preferably 8 to 50 ° C, more preferably 10 to 30 ° C, and even more preferably room temperature. The content of the thermosetting resin composition in the prepreg in terms of solid content is not particularly limited, but is preferably 20 to 90% by mass, more preferably 30 to 85% by mass, and 50 to 80% by mass. % Is more preferable. The thickness of the prepreg is not particularly limited, but is preferably 20 to 150 μm, more preferably 60 to 120 μm, for example.

<Step (2-1) and Step (2-2)>
The step (2-1) is a step of laminating the metal foil 9 on the surface polished in the step (1) to form a metal-clad laminate. On the other hand, in the step (2-2), the metal foil 9 and the thermosetting resin film 10 or the thermosetting resin film 11 with the metal foil are put on the surface 8 polished in the step (1). This is a step of laminating the film 10 so as to be on the polished surface 8 side to form the metal-clad laminate 12. The thermosetting resin film 11 with a metal foil is formed by arranging the thermosetting resin film 10 on the metal foil 9.
After the step (1), either the step (2-1) or the step (2-2) may be selected, but a thermosetting resin layer corresponding to the depth obtained by polishing the cured product of the prepreg is provided. It is preferable to select the step (2-2) in which the above is possible. By selecting the step (2-2), the thickness of the prepreg can be returned to the thickness before polishing regardless of the amount of polishing in the step (1), and can be adjusted to an arbitrary thickness. It is also possible.

The metal of the metal foil 9 (including the metal foil of the thermosetting resin film 11 with a metal foil) is not particularly limited as long as it is used for an electric insulating material, and from the viewpoint of conductivity, copper is used. An alloy containing gold, silver, nickel, platinum, molybdenum, ruthenium, aluminum, tungsten, iron, titanium, chromium, or at least one of these metallic elements is preferred, copper and aluminum are more preferred, and copper is even more preferred. ..
Further, the material of the thermosetting resin film used in the step (2-2) is preferably the same as the thermosetting resin composition contained in the prepreg used in the step (1).

[Metal-clad laminate]
The present invention also provides a metal-clad laminate obtained by the above manufacturing method.
Since the thickness of the cured product inside is substantially uniform, the thickness of the metal-clad laminate of the present invention is also substantially uniform. Specifically, the difference between the maximum value and the minimum value of the thickness is 20 μm or less. It is obtained and has excellent plate thickness accuracy. The difference between the maximum value and the minimum value of the thickness is 10 μm or less for the better one and 5 μm or less for the better one.
Here, the difference between the maximum value and the minimum value of the thickness and the difference between them are the values measured according to the following methods, and more specifically, the values measured according to the method described in Examples.
<Difference between maximum and minimum thickness and calculation method of those differences>
A 550 mm square metal-clad laminate is cut into a 50 mm square size and fragmented into a total of 81 pieces. Select 17 samples including the end and center, and measure the thickness at any 4 points with a micrometer. From the data of 68 points in total, the maximum value, the minimum value, and the difference between them are calculated.

Further, the metal-clad laminate obtained by the manufacturing method of the present invention can have a standard deviation (σ) of thickness of 10 μm or less, and is excellent in plate thickness accuracy. The standard deviation (σ) is 5 μm or less for the better one and 3 μm or less for the better one. _{The standard deviation (σ) of the thickness is, for example, T 1} , T ₂ , ..., T _n when the thicknesses of arbitrary n points of the metal-clad laminate are measured, respectively, and the metal-clad laminates are metal-clad. When the average thickness of the laminated board is T, the standard deviation at n points can be obtained from the following formula.

Further, as one aspect of the metal-clad laminate obtained by the production method of the present invention, (a) a cured product of a prepreg containing a thermosetting resin composition and a base material, at least one of the cured products. Examples thereof include a metal-clad laminate containing a cured product having a polished surface, (b) a thermosetting resin composition layer containing no substrate, and (c) a metal foil. In particular, the metal-clad laminate can be manufactured by going through the steps (1) and (2-2) in the manufacturing method.
The above (a) is not particularly limited, but it is preferable that both sides of the cured product are polished. The preferred embodiment of the polishing method is as described above.

[Printed circuit board]
The present invention also provides a printed wiring board containing the metal-clad laminate.
More specifically, the printed wiring board of the present invention can be manufactured by applying circuit processing to the metal foil of the metal-clad laminate. In circuit processing, for example, after forming a resist pattern on the surface of a metal foil, removing unnecessary metal foil by etching, peeling off the resist pattern, forming necessary through holes by a drill, and forming a resist pattern again, the resist pattern is formed. This can be done by plating the through holes to make them conductive, and finally peeling off the resist pattern. The above-mentioned metal-clad laminate is further laminated on the surface of the printed wiring board thus obtained under the same conditions as described above, and further circuit-processed in the same manner as described above to obtain a multilayer printed wiring board. Can be done. In this case, it is not always necessary to form through holes, via holes may be formed, and both can be formed. Such multi-layering is performed in the required number of sheets.
The printed wiring board of the present invention thus obtained is also excellent in plate thickness accuracy.

[Semiconductor package]
The semiconductor package of the present invention comprises mounting a semiconductor on the printed wiring board of the present invention. The semiconductor package of the present invention can be manufactured by mounting a semiconductor chip, a memory, or the like at a predetermined position on the printed wiring board of the present invention. Since the printed wiring board of the present invention has excellent plate thickness accuracy, the semiconductor package of the present invention can (1) improve the yield at the time of mounting a semiconductor chip, and (2) on a build-up film or a rewiring layer. There is a tendency that the fine wiring formability of L / S = 2 μm / 2 μm or less is improved, (3) the amount of warpage is reduced, and the amount of warpage is unlikely to vary.

[Support for forming coreless substrate]
The present invention also provides a support for forming a coreless substrate, which comprises the metal-clad laminate of the present invention. A coreless substrate can be produced by sequentially laminating an insulating resin composition layer having a circuit pattern on the coreless substrate forming support (core substrate) to form a build-up layer, and then separating the support. It is possible. Since the support for forming a coreless substrate of the present invention has good plate thickness accuracy, warpage and surface waviness of the coreless substrate thus obtained can be reduced, and thus it is suitable for improving the plate thickness accuracy of the coreless substrate.
The method for forming the build-up layer is not particularly limited, and a known method can be adopted. Explaining with reference to FIG. 3, for example, the build-up layer can be formed by the following method.
First, the prepreg 14 is arranged on the coreless substrate forming support (core substrate) 13 of the present invention. The prepreg 14 may be arranged after the adhesive layer is arranged on the coreless substrate forming support (core substrate) 13. Then, the prepreg 14 is heat-cured to form an insulating layer. Next, a via hole 15 is formed by a drill cutting method, a _{laser processing method using a YAG laser, a CO 2} laser, or the like, and then surface roughening treatment and desmear treatment are performed as necessary. Subsequently, the circuit pattern 16 is formed by a subtractive method, a full additive method, a semi-additive method (SAP: Semi Adaptive Process), a modified semi-additive method (m-SAP: modified Semi Adaptive Process), or the like. By repeating the above process, the build-up layer 17 is formed. The coreless substrate 18 is obtained by separating the formed build-up layer 17 from the coreless substrate forming support (core substrate) 13. The build-up layer 17 may be formed on one side of the support (core substrate) 13 or on both sides.

[Support for forming semiconductor rewiring layer]
The present invention also provides a support for forming a semiconductor rewiring layer, which comprises the metal-clad laminate of the present invention. The semiconductor rewiring layer is an insulating layer provided with copper wiring connected to the solder ball, and is usually an insulating layer provided between the semiconductor chip and the solder ball. A resin film for forming a semiconductor rewiring layer is preferably used to form the semiconductor rewiring layer, but the support for forming the semiconductor rewiring layer of the present invention has good plate thickness accuracy, so that the semiconductor is used. It functions effectively as a support for the resin film for forming the rewiring layer.

Next, the present invention will be described in more detail with reference to the following examples, but these examples do not limit the present invention in any sense.

[Example 1]
First, a prepreg was prepared according to the following procedure.
100 parts by mass of both terminal amino-modified silicone compounds, 222 parts by mass of bis (4-maleimidephenyl) methane and 8.5 parts by mass of p-aminophenol were reacted to obtain a modified silicone compound-containing solution. Next, the modified silicone compound-containing solution was added by 16 parts by mass in terms of solid content, 16 parts by mass of naphthol aralkyl type epoxy resin, 69 parts by mass of molten silica [average particle size: 0.5 μm], and 0.15 parts by mass of isocyanate mask imidazole. Was mixed to obtain a varnish having a resin content of 65% by mass. The obtained varnish was impregnated and coated on an E glass cloth having a thickness of 0.1 mm and dried by heating to obtain a prepreg (filling rate of molten silica: 50% by volume).
Eight prepregs thus obtained were laminated, and low-pro type copper foil (thickness 12 μm, maximum height roughness (Rz) about 4.0 μm, manufactured by Mitsui Mining & Smelting Co., Ltd.) was laminated on both sides thereof, and the pressure was 0.5 MPa. By heating and pressure molding at a temperature of 200 to 230 ° C. for about 2 hours, a laminated plate having copper foils on both sides (hereinafter referred to as a copper-clad laminated plate a) was obtained.
Next, using the obtained copper-clad laminate a, the copper foil was removed by etching to obtain a laminate. The surface roughness (Ra) of the surface of the laminate was measured under the following measurement conditions using a high-precision three-dimensional surface shape roughness measurement system (Wyko NT9100, manufactured by Veeco Instruments). The results are shown in FIG.
Next, a grinding device using a diamond bite (automatic surface planar for 300 mm wafers, manufactured by DISCO Inc., trade name "DAS8930") was used to grind both the front and back surfaces (that is, the two surfaces having the largest area) of this laminate. Both sides were polished and flattened. The surface roughness (Ra) of the surface after polishing was measured under the following measurement conditions using a high-precision three-dimensional surface shape roughness measurement system (Wyko NT9100 manufactured by Veeco Instruments). The results are shown in FIG. It was confirmed that the surface waviness was smaller in FIG. 5 than in FIG.
Further, a thermosetting resin film (thickness 10 μm) having the same composition as the prepreg “GEA-705G” is arranged on both sides of the flattened laminate, and a copper foil (thickness 12 μm) is further arranged on the outside thereof. By heating and pressurizing with a hot press, a 550 mm square copper-clad laminate A capable of forming a circuit on the outermost layer was obtained. The cross section of the copper-clad laminate A thus obtained was observed using a digital microscope (manufactured by KEYENCE, trade name "VHX-5000"). The image is shown in FIG.
<Measurement conditions of high-precision 3D surface roughness measurement system>
Internal lens: 1x External lens: 50x Measurement range: Any position within the range of 95 μm (Y-axis) x 95 μm (X-axis) Measurement depth: 10 μm
Measurement method: Vertical scanning interference method (VSI method)

The copper-clad laminates obtained by the above method were evaluated according to the following evaluation methods. The results are shown in Table 1.

<Evaluation method>
(1. Maximum and minimum values of copper-clad laminates and their differences)
The copper-clad laminates obtained in each example were cut into 50 mm square sizes by a wet diamond cutter and sliced into 81 pieces in total. 17 samples including the end and center were selected, and the thickness at any 4 points was measured with a micrometer. From the data of 68 points in total, the maximum value, the minimum value, and the difference between them were calculated.

(2. Drill workability-breaking life)
ULF coated drill "MCW Z699MWU" (φ0.15mm (small diameter) x φ3.5mm (large diameter), manufactured by Union Tool Co., Ltd., trade name) is used as the drill, and the rotation speed is 200,000 rpm and the feed rate is 2.0 m. Drilling was performed under the conditions of / min and tip load: 10.0 μm / rev. The evaluation was performed by making 10,000 hits, and the number of hits (breaking life) until the breakage occurred was obtained, and this was used as an index of drill workability.

[Comparative Example 1]
In Example 1, the surface of the laminated body in the copper-clad laminate a was not polished, and the copper-clad laminate a was used as it was, and each evaluation was performed according to the above method. The results are shown in Table 1.

[Reference Example 1]
In the production of the copper-clad laminate a of Example 1, the copper-clad laminate b was produced in the same manner except that the filling rate of the inorganic filler in the prepreg was increased to 58% by volume. In order to confirm the drill workability when the filling rate of the inorganic filler was increased, the drill workability of the copper-clad laminate b was evaluated according to the above method. The results are shown in Table 1.

From Table 1, the copper-clad laminated plate A obtained in Example 1 has extremely high plate thickness accuracy and good workability (drill workability). On the other hand, the copper-clad laminate a of the comparative example was inferior in plate thickness accuracy to the copper-clad laminate A obtained in Example 1.
In the copper-clad laminate b of Reference Example 1 in which the filling rate of the inorganic filler in the thermosetting resin composition was increased, the workability (drill workability) was lowered.

Since the metal-clad laminate obtained by the manufacturing method of the present invention has excellent plate thickness accuracy, it is useful for printed wiring boards and semiconductor packages for electronic devices.

1 Cured product of prepreg 2 Surface to be polished 3 Central part of cured product 4 Thin part compared to the thickness of the central part of cured product 5 Thinnest part in the cured product 6 Thermosetting resin composition 7 Base material 8 Steps (1) 9 Metal foil 10 Thermosetting resin film 11 Thermosetting resin film with metal foil 12 Metal-clad laminate 13 Support for forming coreless substrate (core substrate)
14 prepreg 15 via hole 16 circuit pattern 17 build-up layer 18 coreless board

Claims (15)

(1) A step of polishing at least one surface of a cured product of a prepreg containing a thermosetting resin composition and a base material.
(2-1) A step of laminating a metal foil on a surface polished in the step (1) to form a metal-clad laminate.
A method for manufacturing a metal-clad laminated board. (1) A step of polishing at least one surface of a cured product of a prepreg containing a thermosetting resin composition and a base material.
(2-2) A metal foil and a thermosetting resin film or a thermosetting resin film with a metal foil are placed on the surface polished in the step (1), and the surface side on which the thermosetting resin film is polished is used. The process of forming a metal-clad laminated board by laminating so as to
A method for manufacturing a metal-clad laminated board. The method for manufacturing a metal-clad laminate according to claim 1 or 2, wherein in the step (1), both sides of the cured product of the prepreg are polished. The method for producing a metal-clad laminate according to any one of claims 1 to 3, wherein the thickness of the cured product of the prepreg is substantially made uniform by polishing in the step (1). The one according to any one of claims 1 to 4, wherein the cured product of the prepreg is obtained by etching and removing the metal foil of the metal-clad laminate whose surface of the cured product inside is not polished. A method for manufacturing a metal-clad laminate. The size of the surface having the largest area of the cured product of the prepreg is 200 mm to 1,300 mm in length × 200 mm to 1,300 mm in width, and at least a part of the surface within 70 mm from the end of the cured product of the prepreg. The method for manufacturing a metal-clad laminate according to any one of claims 1 to 5, wherein the thickness of the metal-clad laminate is thinner than the thickness of the central portion of the cured product. The method for manufacturing a metal-clad laminate according to any one of claims 1 to 6, wherein in the step (1), the entire surface is polished until the thickness of the thinnest portion of the cured product of the prepreg is aligned. In the step (1), (i) CMP (Chemical mechanical polishing) method, (ii) mechanical polishing such as fly cut, grind, sand blast, belt polishing, scrub polishing, (iii) persulfate, hydrogen peroxide-sulfuric acid. The method for producing a metal-clad laminate according to any one of claims 1 to 7, wherein the method is polished by a method selected from the group consisting of a mixture, chemical polishing using an inorganic acid, an organic acid, or the like. The method for manufacturing a metal-clad laminate according to any one of claims 1 to 8, wherein the difference between the maximum value and the minimum value of the thickness of the obtained metal-clad laminate is 20 μm or less. A metal-clad laminate obtained by the manufacturing method according to any one of claims 1 to 9. (A) A cured product of a prepreg containing a thermosetting resin composition and a base material, wherein at least one surface of the cured product is polished, and (b) a heat-cured product containing no base material. A metal-clad laminate containing a sex resin composition layer and (c) a metal foil. A printed wiring board comprising the metal-clad laminate according to claim 10 or 11. A semiconductor package in which a semiconductor element is mounted on the printed wiring board according to claim 12. A support for forming a coreless substrate, which comprises the metal-clad laminate according to claim 10 or 11. A support for forming a semiconductor rewiring layer, comprising the metal-clad laminate according to claim 10.

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