KR102236002B1 - Copper foil with carrier and method of manufacturing printed wiring board by using same - Google Patents

Abstract

Prevents adhesion of foreign substances to the surface of the ultrathin copper layer in the manufacture of printed wiring boards (e.g., a coreless method, etc.), and also prevents scratches and agglomeration of the ultrathin copper layer during peeling of the protective layer. In addition, there is provided a copper foil with a carrier in which no residue remains on the surface of the ultrathin copper layer after peeling of the protective layer. This copper foil with a carrier is formed by providing a carrier layer, a peeling layer, and an ultrathin copper layer in this order. The copper foil with a carrier is formed by further comprising a protective layer on the ultrathin copper layer, the protective layer is adhered to the ultrathin copper layer at at least one protective layer bonding portion, and in the region other than the protective layer bonding portion, the ultrathin copper layer Not glued

Description

Copper foil with carrier and manufacturing method of printed wiring board using the same TECHNICAL FIELD {COPPER FOIL WITH CARRIER AND METHOD OF MANUFACTURING PRINTED WIRING BOARD BY USING SAME}

The present invention relates to a copper foil with a carrier and a method for manufacturing a printed wiring board using the same.

In recent years, in order to increase the mounting density of the printed wiring board and reduce it in size, multilayering of the printed wiring board has been widely performed. Such multilayer printed wiring boards are used for the purpose of reducing weight or size in most of portable electronic devices. Further, this multilayer printed wiring board is required to further reduce the thickness of the interlayer insulating layer and further reduce the weight of the wiring board.

As a technology that satisfies such a demand, a method of manufacturing a printed wiring board in which a wiring layer is formed directly on an ultrathin metal layer and then multi-layered has been proposed, and a manufacturing method using a coreless build-up method is adopted as one of them. And in this coreless build-up method, it is proposed to use a copper foil with a carrier foil for peeling of a support substrate and a multilayer printed wiring board. For example, in Patent Document 1 (International Publication No. 2012/133638), using a copper foil with a carrier foil including at least four layers of a copper foil layer / peeling layer / heat-resistant metal layer / carrier foil, the copper with carrier foil A support substrate with an insulating layer constituent material (coreless support) affixed to the surface of the carrier foil of the foil is obtained, and a build-up wiring layer is formed on the surface of the copper foil layer of the copper foil with the carrier foil of the support substrate A method for manufacturing a multilayer printed wiring board is disclosed in which a multilayer laminate is obtained by separating this from a peeling layer, and the necessary processing is performed on the multilayer laminate to obtain a multilayer printed wiring board.

In the production of a multilayer printed wiring board using a coreless build-up method or the like, there are cases where foreign matter adheres on the copper foil layer. Particularly, when the coreless support is laminated on the surface of the carrier foil, foreign substances such as resin powder derived from the coreless support (prepreg, etc.) may adhere on the copper foil layer. When a circuit is formed on the copper foil layer to which such foreign substances are attached, defects such as disconnection or short circuit may occur in the circuit, resulting in a decrease in yield. Therefore, a copper foil with a carrier foil has been proposed which eliminates the influence caused by adhesion of foreign matters. For example, Patent Document 2 (Japanese Unexamined Patent Application Publication No. 2012-094840) discloses a multilayer metal foil in which a first carrier metal foil, a second carrier metal foil, and a base metal foil are laminated in this order. Even if a foreign material such as a resin powder adheres to it, it is said that by peeling the first carrier metal foil between the second carrier metal foil and the second carrier metal foil, the surface of the second carrier metal foil without the influence of the foreign material can be formed. Between the first carrier metal foil and the second carrier metal foil, it is physically bonded to be peelable through a peeling layer.

International Publication No. 2012/133638 Japanese Unexamined Patent Publication No. 2012-094840

The inventors of the present invention have provided a protective layer that is adhered to the ultra-thin copper layer in at least one bonding portion on the ultra-thin copper layer of the copper foil with a carrier, and is not adhered to the ultra-thin copper layer in other areas. It is possible to prevent adhesion of foreign matters to the surface of the ultrathin copper layer in the manufacture of (e.g., coreless method), and also to prevent scratches and agglomeration of the ultrathin copper layer during peeling of the protective layer. I got the knowledge that I can do it. In addition, the knowledge that the protective layer can be peeled off with zero peel strength by simply cutting off the adhesive portion with the protective layer, and subsequent processing is facilitated because no residue remains on the surface of the ultrathin copper layer after the peeling of the protective layer. Got it.

Accordingly, it is an object of the present invention to prevent adhesion of foreign matters to the surface of the ultrathin copper layer in the manufacture of a printed wiring board (for example, a coreless method, etc.), and also to scratch the ultrathin copper layer at the time of peeling the protective layer. It is intended to provide a copper foil with a carrier that can prevent agglomeration of the roughened surface and the surface of the ultrathin copper layer after peeling of the protective layer.

According to one aspect of the present invention, as a copper foil with a carrier comprising a carrier layer, a peeling layer, and an ultrathin copper layer in this order,

The copper foil with a carrier is formed by further providing a protective layer on the ultrathin copper layer,

A copper foil with a carrier is provided in which the protective layer is adhered to the ultrathin copper layer at at least one protective layer bonding portion, and is not adhered to the ultrathin copper layer in a region other than the protective layer bonding portion.

According to another aspect of the present invention, as a method of manufacturing a printed wiring board,

(a) a step of forming a laminate by laminating the copper foil with a carrier according to the above aspect of the present invention on one or both sides of a coreless support, and

(b) a step of cutting a portion corresponding to a region near the outer periphery of the copper foil with a carrier, including the protective layer bonding portion, and

(c) a step of exposing the ultrathin copper layer by peeling the protective layer from the copper foil with a carrier,

(d) forming a build-up wiring layer on the ultrathin copper layer to produce a laminate with a build-up wiring layer, and

(f) a step of separating the laminate with the build-up wiring layer from the release layer to obtain a multilayer wiring board including the build-up wiring layer;

(g) a step of processing the multilayer wiring board to obtain a printed wiring board,

Including, a method is provided.

1 is a schematic perspective view showing an example of a copper foil with a carrier according to the present invention.
2 is a schematic cross-sectional view showing another example of the copper foil with a carrier of the present invention.
3 is a schematic cross-sectional view showing another example of the copper foil with a carrier of the present invention.
4 is a conceptual diagram for explaining ultrasonic bonding.
5 is a process chart showing an example of a manufacturing method of a copper foil with a carrier according to the present invention.
6 is a process chart showing an example of a method for manufacturing a printed wiring board of the present invention.
Fig. 7 is a process chart showing an example of a method of manufacturing a printed wiring board of the present invention, and is a diagram showing a process following the process shown in Fig. 6;
Fig. 8 is a process chart for explaining an aspect of a method for manufacturing a copper foil with a carrier and a printed wiring board of the present invention.

carrier Attach Copper foil

1 is a schematic perspective view of an example of a copper foil with a carrier according to the present invention. The copper foil 10 with a carrier shown in FIG. 1 comprises a carrier layer 12, a peeling layer 14, and an ultrathin copper layer 16 in this order. This copper foil 10 with a carrier is formed by further providing a protective layer 18 on the ultrathin copper layer 16. By providing the protective layer 18, foreign matters on the surface of the ultrathin copper layer 16 when the coreless support is laminated on the surface of the carrier layer 12 (typically a coreless support (prepreg, etc.) Resin powder, etc.) can be effectively prevented. In particular, the environment in which the lamination process of the coreless support is performed is an environment with low cleanliness with a large amount of scattering from prepregs, etc., and static electricity is easily generated due to friction of the buffer member. In this environment, hydraulic cylinders or hydraulic pumps are installed. For this reason, the lamination step of the coreless support is a step in which foreign matters such as resin powder and cylinder lubricant are generated and easily adhere to the surface of the ultrathin copper layer, that is, the surface of the ultrathin copper layer is easily contaminated. If such a foreign material (especially an organic foreign material) is present on the surface of the ultrathin copper layer 16, when the circuit is formed on the ultrathin copper layer, plating at the place where the foreign material adheres may be insufficient, resulting in defects such as circuit breakage. In addition to the presence, an opening for pattern plating is formed in an unnecessary location, so that defects such as a short circuit (short) may occur. Even in such a situation, by using the copper foil with a carrier of the present invention, since adhesion of foreign matters to the ultrathin copper layer 16 is prevented by the protective layer 18, a circuit is formed on the ultrathin copper layer 16 without foreign matters. can do. As a result, defects such as disconnection or short circuit of the circuit due to foreign matter are less likely to occur, and the yield of the printed wiring board can be improved. In addition, the protective layer 18 is adhered to the ultrathin copper layer 16 in at least one protective layer bonding portion 20, and in the regions 22 other than the protective layer bonding portion 20, the ultrathin copper layer 16 Is not bonded to In this way, the protective layer 18 is locally adhered to the ultrathin copper layer 16 only in the protective layer adhesive portion 20 to form the protective layer non-adhesive region 22, thereby forming the protective layer 18 with the minimum required adhesion area ( The protective layer bonding portion 20 is securely fixed to the ultrathin copper layer 16 to prevent peeling, while in the other non-adhesive areas 22, the factors that deteriorate the surface condition of the ultrathin copper layer 16 are as much as possible. Can be excluded. For example, in the non-adhesive region 22 of the protective layer, since the ultrathin copper layer 16 is not in close contact with the protective layer 18, the ultrathin copper layer 16 at the time of peeling of the protective layer 18 It can prevent scratches and crushing of the roughened surface. In addition, in the non-adhesive region 22 of the protective layer, there is no interlayer between the ultrathin copper layer 16 and the protective layer 18 which imparts peel strength such as a peeling layer, so that the protective layer adhesive portion 20 is provided. By simply cutting, the protective layer 18 can be peeled off from the ultrathin copper layer 16 to zero peel strength. For this reason, since no residue (such as the intermediate layer) remains on the surface of the ultrathin copper layer after peeling of the protective layer, subsequent processing becomes easy. In this way, according to the present invention, adhesion of foreign matters to the surface of the ultrathin copper layer in the manufacture of a printed wiring board (for example, a coreless method, etc.) is prevented, and also scratches and roughening of the ultrathin copper layer when peeling the protective layer It is possible to prevent the screen from being shattered, and to provide a copper foil with a carrier in which no residue remains on the surface of the ultrathin copper layer after peeling of the protective layer.

The carrier layer 12 is a layer (typically thin) for supporting the ultrathin copper layer and improving its handling properties. Examples of the carrier layer include an aluminum foil, a copper foil, a stainless steel (SUS) foil, and a resin film having a metal-coated surface thereof, and preferably a copper foil. The copper foil may be either a rolled copper foil or an electrolytic copper foil. The thickness of the carrier layer is typically 250 µm or less, and preferably 12 µm to 200 µm.

The peeling layer 14 has a function of reducing the peeling strength of the carrier foil, ensuring stability of the strength, and suppressing mutual diffusion that may occur between the carrier foil and the copper foil during press molding at high temperature. It is a layer to have. The release layer is generally formed on one side of the carrier foil, but may be formed on both sides. The peeling layer may be either an organic peeling layer or an inorganic peeling layer. Examples of the organic component used in the organic peeling layer include a nitrogen-containing organic compound, a sulfur-containing organic compound, and a carboxylic acid. Examples of the nitrogen-containing organic compound include a triazole compound, an imidazole compound, and the like, and among them, a triazole compound is preferable from the viewpoint of easy stable releasability. Examples of triazole compounds include 1,2,3-benzotriazole, carboxybenzotriazole, N',N'-bis(benzotriazolylmethyl)urea, 1H-1,2,4-triazole, and 3-amino- 1H-1,2,4-triazole, etc. are mentioned. Examples of the sulfur-containing organic compound include mercaptobenzothiazole, thiocyanuric acid, 2-benzimidazolthiol, and the like. Examples of carboxylic acids include monocarboxylic acids and dicarboxylic acids. On the other hand, examples of the inorganic components used in the inorganic peeling layer include Ni, Mo, Co, Cr, Fe, Ti, W, P, Zn, and chromate treatment films. In addition, the release layer may be formed by bringing the release layer component-containing solution into contact with at least one surface of the carrier foil, and fixing the release layer component to the surface of the carrier foil. When the carrier foil is brought into contact with the release layer component-containing solution, this contact may be performed by immersion in the release layer component-containing solution, spraying of the release layer component-containing solution, and the flow of the release layer component-containing solution. In addition, a method of forming a film of the release layer component by vapor deposition or sputtering may be employed. In addition, fixing of the release layer component to the carrier foil surface may be performed by drying the release layer component-containing solution, electrodeposition of the release layer component in the release layer component-containing solution, or the like. The thickness of the release layer is typically 1 nm to 1 µm, preferably 5 nm to 500 nm. In addition, the peel strength between the release layer 14 and the carrier foil is preferably 7 gf/cm to 50 gf/cm, more preferably 10 gf/cm to 40 gf/cm, and more preferably 15 gf/cm to 30 gf/cm. .

The ultrathin copper layer 16 is not particularly limited as long as it is a well-known configuration employed for ultrathin copper foil with a carrier. For example, the ultrathin copper layer 16 may be formed by a wet film forming method such as an electroless copper plating method and an electrolytic copper plating method, a dry film forming method such as sputtering and chemical vapor deposition, or a combination thereof. The preferred thickness of the ultrathin copper layer 16 is 0.05 µm to 7 µm, more preferably 0.075 µm to 5 µm, and still more preferably 0.09 µm to 4 µm. It is preferable that the ultrathin copper layer 16 is formed by providing a rough surface on the surface on the protective layer side. By setting it as a rough surface, it is possible to improve the adhesiveness with the metal layer or the resin layer in manufacturing a printed wiring board. It is preferable that the arithmetic mean roughness Ra of the rough surface measured in accordance with JIS B 0601 (2001) is 50 nm or more, more preferably 50 to 1000 nm, further preferably 80 to 800 nm. Since the roughened surface has a delicate microstructure, it has the property of being easily scratched with slight contact. However, in the copper foil with a carrier of the present invention, the ultrathin copper layer 16 is formed in the non-adhesive region 22 of the protective layer. Since it is not in close contact with the protective layer 18, it is possible to prevent agglomeration of the rough surface of the ultrathin copper layer 16 at the time of peeling of the protective layer 18. In this way, it is possible to prevent adhesion of foreign matters to the surface of the ultrathin copper layer 16 while maintaining a desirable shape of the rough surface.

If desired, another functional layer may be provided between the release layer 14 and the carrier layer 12 and/or the ultrathin copper layer 16. Examples of such other functional layers include auxiliary metal layers. It is preferable that the auxiliary metal layer is made of nickel and/or cobalt. By forming such an auxiliary metal layer on the surface side of the carrier layer 12 and/or the surface side of the ultrathin copper layer 16, the carrier layer 12 and the ultrathin copper layer 16 are formed during hot press forming at high temperature or for a long time. By suppressing mutual diffusion that may occur between the carrier layers, stability of the peeling strength of the carrier layer can be ensured. It is preferable that the thickness of the auxiliary metal layer is 0.001 to 3 µm.

The protective layer 18 is not particularly limited as long as it covers the surface of the ultrathin copper layer 16 to prevent adhesion of foreign matters, but a metal foil or a resin film is preferable from the viewpoint of good handling properties, and a metal foil is more preferable. Antistatic treatment may be applied to the surface of the metal foil or the resin film. In addition, it is preferable that no adhesive is applied to the surface of the protective layer 18 in order to secure the non-adhesive region 22 of the protective layer. When the protective layer 18 is a metal foil, examples of the metal foil include aluminum foil, iron foil, stainless steel (SUS) foil, titanium foil, and copper foil. Aluminum foil, iron foil, stainless steel (SUS) foil, and titanium foil, which are metal foils having a lower specific gravity than copper constituting the layer 16, are preferable. More preferably, an aluminum foil, which is a metal foil having a lower elastic modulus than that of copper constituting the ultrathin copper layer 16, is particularly preferred in that the surface of the ultrathin copper layer 16 is not scratched. The thickness of the protective layer 18 is preferably 10 to 300 µm, more preferably 12 to 200 µm, and still more preferably 15 to 100 µm.

In addition, at least the surface of the protective layer 18 on the side opposite to the ultrathin copper layer 16 is prevented from scratching the surface of the ultrathin copper layer 16 due to friction with the surface of the ultrathin copper layer 16 in contact. In order to prevent it, it is desirable to be smooth enough to not cause slippage due to handling. Specifically, the surface of the protective layer 18 preferably has an arithmetic mean roughness Ra of 400 nm or less, more preferably 20 to 350 nm, and still more preferably 30 to the surface of the protective layer 18 measured in accordance with JIS B 0601 (2001). 320 nm. In addition, the surface of the protective layer 18 on the side not facing the ultrathin copper layer 16 is also within the range of the arithmetic mean roughness, which prevents the occurrence of foreign matter due to friction during packing of the copper foil with a carrier. It is preferable in

The protective layer 18 is adhered to the ultrathin copper layer 16 in at least one protective layer bonding portion 20, and in the non-adhesive areas 22 of the protective layer other than the protective layer bonding portion 20, the ultrathin copper layer 16 ) Is not adhered to. Since the protective layer bonding portion 20 is cut off during the manufacturing of the printed wiring board, the outer periphery of the copper foil with a carrier can be secured to maximize the area in which the build-up wiring layer can be formed by securing the protective layer non-adhesive area 22 as wide as possible. It is preferable that it is installed in a desired shape, preferably a linear shape and/or a point shape in the vicinity. By providing the protective layer bonding portion 20 in a linear shape and/or a point shape, the protective layer 18 can be adhered to the ultrathin copper layer 16 at a position as close to the outer periphery as possible with a minimum bonding area. In order to prevent the protective layer 18 from bulging from one side, the protective layer bonding portion 20 is preferably provided in the vicinity of at least two opposite sides constituting the outer periphery of the copper foil 10 with a carrier, and three sides It may be provided in the vicinity of the four sides. When installed in the vicinity of the four sides, the protective layer bonding portion 20 having a linear or point-shaped shape in the vicinity of the four sides may be formed so as to exhibit a rim shape or an open shape of a regular shape as a whole. Moreover, on each side mentioned above, it may be provided in a continuous linear shape, and may be provided in a point shape on arbitrary coordinates on the side. The vicinity of the outer periphery of the copper foil with a carrier to the vicinity of the side constituting the outer periphery is preferably a region within 0 to 50 mm from the outer edge of the ultrathin copper layer, and more preferably within 1 to 45 mm from the outer edge. It is an area, and more preferably, it is a 3-40 mm inner area. That is, as shown in FIG. 2, the protective layer bonding portion 20 may be formed on the outer edge of the ultrathin copper layer, and as shown in FIGS. 1 and 3, the protective layer bonding portion 20 is predetermined from the outer edge of the ultrathin copper layer. It may be formed in a region inside the street. Further, when the protective layer bonding portion 20 is provided in a linear shape, the bonding width is preferably 0.05 to 10 mm, more preferably 0.1 to 8 mm, and still more preferably 0.2 to 6 mm.

The adhesion in the protective layer bonding portion 20 may be performed by a method capable of adhering the protective layer 18 and the ultrathin copper layer 16 so as not to be easily peeled off, and is not particularly limited, but ultrasonic bonding, laser bonding, It is preferable that it is performed by at least any one selected from the group consisting of seam bonding and adhesive application, and particularly preferably, it is ultrasonic bonding in that welding can be reliably and efficiently while applying a load. Ultrasonic bonding (also referred to as ultrasonic welding), as schematically shown in Fig. 4, the bonding object 100 made of two or more materials is connected to a solid wall 102 and an ultrasonic transmitting terminal (horn) 104. It can be performed by sandwiching it between and transmitting ultrasonic vibration to the object to be bonded 100 while applying a load L (pressure) to the ultrasonic transmitting terminal 104. At this time, the bonding is achieved by alloying the bonding interface by locally reaching a high temperature close to several hundred to 1,000°C at the maximum point of the ultrasonic amplitude. The conditions used for ultrasonic bonding are not particularly limited, but the ultrasonic frequency is preferably 5 to 100 kHz, and more preferably 10 to 80 kHz. The output is preferably 100 to 5000 W, more preferably 200 to 4000 W. The load (pressing force) is preferably 0.05 to 500 MPa, more preferably 0.5 to 300 MPa, and more preferably 1 to 100 MPa. Further, by performing ultrasonic bonding at a high frequency, the bonding effect is enhanced. Therefore, it is advantageous to perform ultrasonic bonding at a high frequency and at a high conveying speed (that is, a short transfer time) in that damage other than the bonding portion is reduced. Above all, when the object to be joined is large (thick), a large pressing force and a long transmission time are required. In addition, a large output is required in order to vibrate the terminal with a large pressing force. Therefore, it is desirable to appropriately determine all conditions while taking these factors into consideration.

The carrier layer 12 is an ultrathin copper layer ( It is preferable that it is adhered to 16). By providing this carrier layer bonding portion 24, it is possible to prevent the penetration of the chemical liquid between the carrier layer 12 and the ultrathin copper layer 16 at the time of forming the build-up wiring. If such a chemical solution is allowed to permeate during the formation of the build-up wiring, there is a concern that peeling of the copper foil with the carrier foil may be promoted, resulting in a decrease in manufacturing yield. In this respect, such a problem can be avoided or reduced by providing the carrier layer bonding portion 24. In particular, masking the end face of the copper foil with a carrier with a tape or the like to prevent the penetration of the chemical solution has been performed before, but by providing the carrier layer bonding portion 24 such troublesome masking can be eliminated, simplifying the manufacturing process. I can plan. Above all, it goes without saying that the carrier layer bonding portion 24 and the masking according to the present embodiment may be used in combination.

As shown in Figs. 1 to 3, at least a part of the carrier layer bonding portion 24 does not overlap with the protective layer bonding portion 20, and is located in an area inside the area 22 surrounded by the protective layer bonding portion 20. It is desirable to be installed. By doing so, the protective layer adhesive portion 20 can be cut off while leaving at least a portion of the carrier layer adhesive portion 24 located in the inner region, so that the protective layer adhesive portion 20 and the protective layer 18 are removed. Also in this case, the effect of preventing penetration of the drug by the carrier layer bonding portion 24 can be reliably obtained.

It is preferable that the carrier layer bonding portion 24 is provided in an elongated shape in the vicinity of the opposite two or four sides constituting the outer periphery of the copper foil 10 with a carrier. With such a configuration, it is possible to reliably prevent peeling of the carrier layer 12 and the ultrathin copper layer 16, and also prevent or suppress the invasion of the chemical solution into the carrier layer 12 and the ultrathin copper layer 16. . Therefore, the carrier layer bonding portion 24 is more preferably installed in a long shape near the four sides than only the two sides constituting the outer circumference, and most preferably four carrier layers installed in a longer shape near the four sides. It is preferable that the bonding portions 24 contact each other or intersect each other to form a border-shaped or sperm-shaped region. According to this configuration, intrusion of the chemical liquid into the carrier layer 12 and the ultrathin copper layer 16 can be prevented more reliably. Here, the vicinity of the side constituting the outer periphery of the carrier-attached copper foil with respect to the carrier layer bonding portion 24 is preferably an area inside the area 22 surrounded by the protective layer bonding portion 20, and is preferably ultrathin. It is a region 1 to 50 mm inside from the outer edge of the copper layer, more preferably a region inside 2 to 40 mm from the outer edge, and more preferably 3 to 30 mm inside. Further, when the carrier layer bonding portion 24 is provided in a long shape, the bonding width is preferably 0.05 to 10 mm, more preferably 0.1 to 8 mm, and still more preferably 0.2 to 6 mm.

The adhesion in the carrier layer bonding portion 24 may be performed by a method capable of reliably bonding the carrier layer 12 and the ultrathin copper layer 16, and is not particularly limited, but consists of ultrasonic bonding, laser bonding, and seam bonding. It is preferable that it is performed by at least any one selected from the group, and particularly preferably, it is ultrasonic bonding in that welding can be reliably and efficiently while applying a load. Details of the ultrasonic bonding are as described above.

2 and 3, the protective layer bonding portion 20 may be partially overlapped with the carrier layer bonding portion 24. This form is a configuration that can be realized at the same time when forming the protective layer bonding portion 20 by bonding such as ultrasonic bonding, laser bonding, seam bonding, or the like. That is, according to this bonding method, by appropriately setting the matching conditions, bonding of the protective layer 18 and the ultrathin copper layer 16 (that is, formation of the protective layer bonding portion 20), the carrier layer 12 and the ultrathin copper layer The bonding of (16) (that is, the formation of the carrier layer bonding portion 24) can be realized at the same time. In this case, since the adhesive is not used, there is an advantage that it is not necessary to consider the area where the adhesive spreads. In addition, since the protective layer bonding portion 20 is integrated with the carrier layer bonding portion 24, handling resistance such as that the carrier layer 12 is difficult to peel from the integral product even if the copper foil attached to the carrier is bent or handled cumbersomely. There is an advantage that it is excellent.

An example of a preferred method of manufacturing a copper foil 10 with a carrier having not only the protective layer bonding portion 20 but also the carrier layer bonding portion 24 is shown in FIG. 5. In the manufacturing method shown in FIG. 5, as shown in FIG. 5(A), a copper foil 11 with a carrier without a protective layer is prepared, and for this, as shown in FIG. 5(B), ultrasonic waves are applied. Using an adhesive method such as bonding, the carrier layer 12 is formed of an ultrathin copper layer ( 16). Next, as shown in Fig. 5C, the protective layer 18 is placed on the carrier-attached copper foil 11 without the protective layer on which the carrier layer bonding portion 24 is formed. Finally, as shown in (D) of FIG. 5, by using an adhesive method such as ultrasonic bonding, the protective layer bonding portion 20 constitutes the outer periphery of the copper foil 10 with a carrier in the vicinity of at least two opposite sides. It is preferable to adhere the protective layer 18 to the ultrathin copper layer 16 so as to be installed in the. At this time, at least a part of the carrier layer adhesive portion 24 does not overlap with the protective layer adhesive portion 20, and is preferably provided in a region inside the region 22 surrounded by the protective layer adhesive portion 20. By doing so, the protective layer adhesive portion 20 can be cut off while leaving at least a portion of the carrier layer adhesive portion 24 located in the inner region, so that the protective layer adhesive portion 20 and the protective layer 18 are removed. Also in this case, the effect of preventing penetration of the drug by the carrier layer bonding portion 24 can be reliably obtained. In addition, it is also preferable to realize adhesion between the carrier layer 12 and the ultrathin copper layer 16 in the area immediately below the protective layer bonding portion 20 to form a part of the carrier layer bonding portion 24, and this configuration is When forming the protective layer bonding portion 20 by a bonding method such as ultrasonic bonding, it can be formed at the same time.

In Fig. 8, the formation of the carrier layer bonding portion 24 and the bonding of the protective layer 18 (that is, the formation of the protective layer bonding portion 20) by ultrasonic bonding to the copper foil 11 with a carrier without a protective layer taken out from the roll. ) Is shown. First, as shown in Fig.8(A), the copper foil 11 with a carrier without a protective layer drawn out from the roll is in a long shape in a direction parallel and perpendicular to the conveying direction by ultrasonic bonding (that is, a sperm shape As) carrier layer adhesive portion 24 is formed. Next, as shown in (B) of Fig. 8, the protective layer 18 (for example, aluminum foil) is placed on the ultrathin copper layer 16, and near both ends of the long-shaped carrier-attached copper foil. The protective layer bonding portion 20 is formed by ultrasonic bonding in a linear shape. In this way, the long-shaped copper foil with a carrier on which the protective layer 18 is provided is cut at the center of the carrier layer bonding portion 24 formed in the thin width direction, and a sheet piece shape as shown in Fig. 8C. A copper foil (10) with a carrier is obtained. In this sheet piece-shaped copper foil 10 with a carrier, a carrier layer bonding portion 24 is formed in the vicinity of the four sides constituting the outer circumference in a rim shape in parallel with these sides, and the carrier layer bonding portion 24 in the shape of the frame A protective layer bonding portion 20 is formed outside of) and in the vicinity of two opposite sides. In this way, after laminating a coreless support (not shown) using a copper foil with a carrier bonded in the vicinity of the two sides to which the protective layer 18 faces, the protective layer adhesive portion as shown in FIG. 8(D) The area including (20) is cut outside the area surrounded by the carrier layer bonding portion 24. In this way, the protective layer 18 was peeled off while leaving the carrier layer bonding portion 24 contributing to the prevention of penetration of the chemical solution during the formation of the build-up wiring layer in a rim shape near the outer circumference, and as shown in FIG. It is in a form suitable for formation of the same build-up wiring layer. In addition, it is assumed that the carrier layer bonding portion 24 includes a form in which the bonding portion of the carrier layer and the ultrathin copper layer is formed in parallel not only one side but also a plurality of sides.

print Of the wiring board Manufacturing method

A printed wiring board can be preferably manufactured using the copper foil with a carrier of the present invention described above. According to a preferred aspect of the present invention, the production of a printed wiring board comprises (a) laminating the copper foil with a carrier of the present invention on one or both sides of a coreless support, and (b) a copper foil with a carrier including a protective layer bonding portion. A portion corresponding to the region near the outer circumference was excised, (c) the protective layer was peeled from the copper foil with a carrier to expose the ultrathin copper layer, (d) a build-up wiring layer was formed on the ultrathin copper layer, (f) It can be performed by separating the obtained laminated body with a build-up wiring layer from the peeling layer, and processing (g) the obtained multilayer wiring board. As described above, by using the copper foil with a carrier of the present invention, adhesion of foreign matters to the surface of the ultrathin copper layer at the time of lamination of the coreless support body is prevented, and the ultrathin copper layer at the time of peeling of the protective layer is prevented. A printed wiring board can be manufactured by a method in which scratches and agglomeration of the roughened surface can be prevented, and furthermore, residues are not left on the surface of the ultrathin copper layer after peeling the protective layer.

Hereinafter, each process will be described with reference to FIGS. 6 and 7. In addition, the aspect shown in Figs. 6 and 7 is drawn as to form the build-up wiring layer 36 by installing a copper foil 10 with a carrier on one side of the coreless support 28 for simplicity of explanation. It is preferable to provide copper foils 10 with carriers on both surfaces of the lease support 28 to form build-up wiring layers 36 on both surfaces.

(a) formation of a laminate

In this step (a), as shown in Fig. 6A, the copper foil 10 with a carrier according to the above-described aspect of the present invention is laminated on one side or both sides of the coreless support 28 and laminated. Form a sieve. This lamination may be performed in accordance with known conditions and methods employed for lamination of copper foil and prepreg in an ordinary printed wiring board manufacturing process. The coreless support 28 is typically made of a resin, preferably an insulating resin. The coreless support 28 is preferably a prepreg and/or a resin sheet, and more preferably a prepreg. Prepreg is a generic term for a composite material in which a synthetic resin is impregnated into a substrate such as a synthetic resin plate, a glass plate, a glass woven fabric, a glass nonwoven fabric, or paper. Preferred examples of the insulating resin impregnated in the prepreg include an epoxy resin, a cyanate resin, a bismaleimide triazine resin (BT resin), a polyphenylene ether resin, a phenol resin, and the like. Moreover, as an example of the insulating resin which comprises a resin sheet, insulating resins, such as an epoxy resin, a polyimide resin, and a polyester resin, are mentioned. In addition, the coreless support 28 may contain filler particles made of various inorganic particles such as silica and alumina from the viewpoint of improving insulation. The thickness of the coreless support 28 is not particularly limited, but is preferably 3 to 1000 µm, more preferably 5 to 400 µm, and still more preferably 10 to 200 µm.

(b) ablation of the adhesive part of the protective layer

In this step (b), a portion corresponding to a region in the vicinity of the outer periphery of the copper foil 10 with a carrier including the protective layer bonding portion 20 is excised. At this time, it is preferable to cut from the inside of the area surrounded by the protective layer bonding portion 20 and outside the carrier layer bonding portion 24 (if any), as shown by the dotted line in FIG. 6A. By doing this, only the protective layer adhesive portion 20 that has secured the protective layer 18 and the ultra-thin copper layer 16 is removed while leaving the carrier layer adhesive portion 24 (if present), so that the desired function is secured and protected. It becomes possible to peel off the layer 18 extremely easily.

(c) peeling of the protective layer

In this process (c), as shown in FIG. 6(B), the protective layer 18 is peeled from the copper foil 10 with a carrier, and the ultrathin copper layer 16 is exposed. At this time, since the protective layer bonding portion 20 does not already exist in the protective layer 18, the protective layer 18 can be very easily peeled off. The protective layer 18 is in a non-contact or near non-contact state to the ultrathin copper layer 16, and there is no intermediate layer interposed therebetween, which imparts peeling strength such as a peeling layer, so the protective layer 18 is made of ultrathin copper. It becomes possible to peel off from the layer 16 to zero peel strength (that is, no resistance at the time of peeling occurs), and the occurrence of scratches can also be prevented. In addition, since no residue (such as the intermediate layer) remains on the surface of the ultrathin copper layer 16 after peeling of the protective layer 18, subsequent processing becomes easy.

(d) formation of the build-up wiring layer

In this step (d), the build-up wiring layer 36 is formed on the ultrathin copper layer 16 to produce a laminate with a build-up wiring layer. For example, as shown in Figs. 6C and 7D, the first wiring layer 30, the insulating layer 32, and the second wiring layer 34 on the ultrathin copper layer 16 It may be formed in this order to form a build-up wiring layer 36. The first wiring layer 30 is formed by a pattern plating method. The construction method for the method of forming the build-up layer after the second wiring layer 34 is not particularly limited, and the subtractive method, MSAP (modified semi-additive process) method, SAP (semi-additive) method, full Additive method, etc. can be used. For example, in the case of bonding a metal foil represented by a resin layer and a copper foil at the same time by press working, the panel plating layer and the metal foil are etched in combination with formation of via holes and interlayer conduction means such as panel plating, and the wiring pattern Can be formed. Further, when only the resin layer is adhered to the surface of the ultrathin copper layer 16 by pressing or laminating, a wiring pattern may be formed on the surface by a semi-additive method. In any case, when the copper foil with a carrier has the carrier layer bonding portion 24, it is possible to prevent the seepage of the chemical liquid between the carrier layer 12 and the ultrathin copper layer 16 at the time of forming the build-up wiring. If permeation of the chemical solution is allowed during the formation of the build-up wiring, the peeling of the copper foil attached to the carrier foil is promoted, which may lead to delamination of the build-up layer or dropping of the first wiring layer 30, thereby reducing manufacturing yield. It may be caused, but by the presence of the carrier layer adhesion portion 24 such a problem can be avoided or reduced.

The above process is repeated as necessary to obtain a laminate with a build-up wiring layer. In this step, it is preferable to form a build-up wiring layer in which a resin layer and a wiring layer including a wiring pattern are alternately stacked and arranged to obtain a laminate with a build-up wiring layer. This step may be repeated until a build-up wiring layer having a desired number of layers is formed. In this step, if necessary, bumps for mounting such as solder resist or filler may be formed on the outer layer surface. In addition, the outermost layer surface of the build-up wiring layer may form an outer layer wiring pattern in a later processing step (g) of a multilayer wiring board.

As shown in Fig. 6C, it is preferable that the step (d) includes a step of directly forming a wiring (the first wiring layer 30) on the surface of the ultrathin copper layer. For example, in the first step of forming the build-up wiring layer 36, the surface of the ultra-thin copper layer 16 is coated with a plating resist, etc. to cover other than the portion where the wiring is formed, and the portion where the wiring is formed is coated with copper, etc. You may form and use a wiring pattern made of in advance. In addition, a wiring pattern made of gold, tin, nickel, or the like may be formed in advance and used at a portion where wiring is to be formed. By doing so, it is possible to obtain a laminate with a build-up wiring layer in a state in which the outer layer wiring pattern on one side is already assembled.

(e) Optional process (removal of the adhesive portion of the carrier layer)

This step (e) is an arbitrary step of removing the carrier layer bonding portion 24 performed between the step (d) and the step (f) when the copper foil 10 with a carrier has the carrier layer bonding portion 24 to be. As a prerequisite for performing this step (e), at least a part of the carrier layer bonding portion 24 does not overlap with the protective layer bonding portion 20, and is provided in an area inside the area surrounded by the protective layer bonding portion 20. , It is a requirement that the portion to be cut in step (b) is a portion outside the carrier layer bonding portion 24. Therefore, in this process (e), the laminated body with the build-up wiring layer is cut|disconnected at a position inside the carrier layer bonding part 24, and the part corresponding to the area|region near the outer periphery of the copper foil with a carrier is cut off accordingly. In this way, an unnecessary region including the carrier layer bonding portion 24 is excised from the laminate with the build-up wiring layer to expose the cross section of the carrier layer non-adhesive region 26 of the copper foil 10 with a carrier. By doing so, it becomes easy to separate the ultrathin copper layer 16 from the carrier layer 12 in the subsequent process (e). In this embodiment, since the carrier layer bonding portion 24 is cut off, it is preferable that the build-up wiring layer 36 in step (d) be formed in a region inside the carrier layer bonding portion 24.

(f) Separation of the laminate with the build-up wiring layer

In this step (f), as shown in Fig. 7(E), the multilayer wiring board 38 including the build-up wiring layer 36 is obtained by separating the laminate with the build-up wiring layer from the release layer 14. . Separation at the interface between the ultrathin copper layer 16 and the peeling layer 14 can be performed by peeling off the ultrathin copper layer 16 and/or the carrier layer 12.

(g) Multilayer wiring board processing

In this step (g), the multilayer wiring board 38 is processed to obtain the printed wiring board 40. In this step, the multilayer wiring board 38 obtained by the separation step is used to form a desired multilayer printed wiring board. As a processing method from the multilayer wiring board 38 to the multilayer printed wiring board 40, various known methods may be employed. For example, the ultrathin copper layer 16 in the outer layer of the multilayer wiring board 38 is etched to form an outer circuit wiring to obtain a multilayer printed wiring board. Further, the ultrathin copper layer 16 on the outer layer of the multilayer wiring board 38 can be completely etched away, and used as the multilayer printed wiring board 40 as it is. In addition, the ultrathin copper layer 16 on the outer layer of the multilayer wiring board 38 is completely etched away, and the outer layer circuit is directly formed by forming a circuit shape with a conductive paste on the surface of the exposed resin layer or by a semi-additive method. In other words, it is also possible to obtain a multilayer printed wiring board. In addition, by completely etching away the ultrathin copper layer 16 on the outer layer of the multilayer wiring board 38 and soft etching the first wiring layer 30, a first wiring layer 30 having a concave portion is obtained, which is used for mounting. It is also possible to use a pad.

Claims (16)

As a copper foil with a carrier provided with a carrier layer, a peeling layer, and an ultrathin copper layer in this order,
The copper foil with a carrier is formed by further providing a protective layer on the ultrathin copper layer,
The protective layer is adhered to the ultrathin copper layer at at least one protective layer bonding portion, and is not adhered to the ultrathin copper layer in a region other than the protective layer bonding portion,
The carrier layer is adhered to the ultrathin copper layer so that it is more difficult to peel than in regions other than the carrier layer adhesive portion in at least one carrier layer adhesive portion,
At least a part of the carrier layer bonding portion does not overlap with the protective layer bonding portion, and is provided in a region inside the area surrounded by the protective layer bonding portion. The method of claim 1,
The copper foil with a carrier, wherein the protective layer bonding portion is provided in a linear shape and/or a dot shape in a region within 0 to 50 mm from the outer edge of the ultrathin copper layer of the copper foil with a carrier. The method of claim 2,
The copper foil with a carrier, wherein the protective layer bonding portion is provided in a region within 0 to 50 mm from the outer peripheries of at least two sides constituting the outer periphery of the ultrathin copper layer of the copper foil with a carrier. The method of claim 1,
The carrier layer adhesive portion is provided in a long shape in a region within 1 to 50 mm from the outer periphery of the opposite two or four sides constituting the outer periphery of the ultra-thin copper layer of the carrier-attached copper foil. foil. The method of claim 1,
A copper foil with a carrier, wherein the ultrathin copper layer has a rough surface on the protective layer side. The method of claim 5,
The copper foil with a carrier, wherein the arithmetic mean roughness Ra of the rough surface is 50 nm or more. The method of claim 1,
The copper foil with a carrier, wherein the protective layer is a metal foil or a resin film. The method of claim 1,
The copper foil with a carrier, wherein the protective layer adhesive portion is overlapped with a part of the carrier layer adhesive portion. The method of claim 1,
The copper foil with a carrier, wherein the bonding in the protective layer bonding portion is performed by at least any one selected from the group consisting of ultrasonic bonding, laser bonding, seam bonding, and adhesive bonding. The method of claim 1,
The copper foil with a carrier, wherein the bonding in the carrier layer bonding portion is performed by at least any one selected from the group consisting of ultrasonic bonding, laser bonding, and seam bonding. As a method of manufacturing a printed wiring board,
(a) a step of laminating the copper foil with a carrier according to any one of claims 1 to 10 on one or both sides of a coreless support to form a laminate, and
(b) a step of cutting off a portion of the copper foil with a carrier, including the protective layer bonding portion,
(c) a step of exposing the ultrathin copper layer by peeling the protective layer from the copper foil with a carrier,
(d) forming a build-up wiring layer on the ultrathin copper layer to produce a laminate with a build-up wiring layer, and
(f) a step of separating the laminate with the build-up wiring layer from the release layer to obtain a multilayer wiring board including the build-up wiring layer;
(g) a step of processing the multilayer wiring board to obtain a printed wiring board,
Including, the method. The method of claim 11,
The method, wherein the step (d) includes a step of directly forming a wiring on the surface of the ultrathin copper layer. As a method of manufacturing a printed wiring board,
(a) a step of forming a laminate by laminating the copper foil with a carrier according to claim 1 on one or both sides of a coreless support, and
(b) a step of cutting out a portion outside the carrier layer bonding portion as a portion of the copper foil with a carrier including the protective layer bonding portion,
(c) a step of exposing the ultrathin copper layer by peeling the protective layer from the copper foil with a carrier,
(d) forming a build-up wiring layer on the ultrathin copper layer to produce a laminate with a build-up wiring layer, and
(e) a step of cutting the laminated body with the build-up wiring layer at a position inside the carrier layer bonding portion, thereby cutting off a portion including the carrier layer bonding portion of the copper foil with a carrier;
(f) a step of separating the laminate with the build-up wiring layer from the release layer to obtain a multilayer wiring board including the build-up wiring layer;
(g) a step of processing the multilayer wiring board to obtain a printed wiring board,
Including, the method. The method of claim 13,
The method, wherein the formation of the build-up wiring layer in the step (d) is performed in a region inside the carrier layer bonding portion. delete delete

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