Printed wiring board manufacturing method, semiconductor package manufacturing method, and layered film

Abstract

Provided is a printed wiring board manufacturing method in which despite the use of a photosensitive resin composition containing an inorganic filler, a printed board demonstrating high adhesiveness to copper plating is achieved. Further provided are: a manufacturing method for a semiconductor package that includes the printed wiring board; and a layered film. The printed wiring board manufacturing method includes performing operations in the following order. (1) Applying a photosensitive resin composition containing an inorganic filler onto a carrier film to form a photosensitive resin film on the carrier film. (2) Placing a protective film on an upper surface of the photosensitive resin film that has been formed. (3) Peeling off the carrier film while the protective film remains attached to the photosensitive resin film. (4) Attaching the photosensitive resin film surface exposed by (3) above to a circuit board.

Description

Method for manufacturing printed circuit boards, method for manufacturing semiconductor packages, and laminated film

[0001] This disclosure relates to a method for manufacturing printed circuit boards, a method for manufacturing semiconductor packages, and a laminated film.

[0002] In recent years, as electronic devices have become smaller and more high-performance, printed circuit boards (PCBs) have seen increased density due to an increase in the number of circuit layers and miniaturization of wiring. In particular, the density of semiconductor package substrates such as BGAs (Ball Grid Arrays) and CSPs (Chip Size Packages) on which semiconductor chips are mounted has been remarkable, requiring not only miniaturization of wiring but also thinning of the insulating layer and further reduction in the diameter of vias (also called via holes) used for interlayer connections.

[0003] In recent years, it has been proposed to use a photosensitive resin composition that can form a large number of small-diameter vias simultaneously by photolithography as a material for the interlayer insulating layer of printed circuit boards (see, for example, Patent Document 1). Patent Document 1 discloses a photosensitive resin composition containing (A) an active ester-based curing agent, (B) a carboxyl group-containing radical polymerizable compound, (C) a photopolymerization initiator, (D) an epoxy resin, (E) a curing accelerator, and (F) an inorganic filler.

[0004] Japanese Patent Publication No. 2013-214057

[0005] However, as the inventors continued their research on photosensitive resin compositions for interlayer insulating layers, they discovered that when a photosensitive resin film made using a photosensitive resin composition containing an inorganic filler was used as an interlayer insulating layer, and copper plating was applied to the photosensitive resin film, the adhesive strength between the interlayer insulating layer and the copper plating tended to be low.

[0006] Therefore, the object of this disclosure is to provide a method for manufacturing a printed circuit board that exhibits high adhesive strength to copper plating while using a photosensitive resin composition containing an inorganic filler, and to provide a method for manufacturing a semiconductor package having the printed circuit board and a laminated film.

[0007] As a result of diligent research, the present inventors have found that the above-mentioned objectives can be achieved by this disclosure. This disclosure includes the following embodiments [1] to

[13] . [1] A method for manufacturing a printed circuit board, comprising the following steps: (1) Applying a photosensitive resin composition containing an inorganic filler to a carrier film to form a photosensitive resin film on the carrier film. (2) Placing a protective film on the upper surface of the formed photosensitive resin film. (3) Peeling off the carrier film while the protective film remains attached to the photosensitive resin film. (4) Attaching the exposed photosensitive resin film surface to a circuit board. [2] The method for manufacturing a printed circuit board according to [1], wherein the peeling force between the carrier film and the photosensitive resin film is smaller than the peeling force between the protective film and the photosensitive resin film. [3] The method for manufacturing a printed circuit board according to [1] or [2], wherein the carrier film is treated with a release agent on the side to which the photosensitive resin composition is applied. [4] The method for manufacturing a printed circuit board according to any one of [1] to [3] above, wherein in the photosensitive resin film formed in (1), the proportion of inorganic filler in the range of 1 to 10 μm thickness from the protective film side is smaller than the proportion of inorganic filler in the range of 1 to 10 μm thickness from the carrier film side. [5] The method for manufacturing a printed circuit board according to any one of [1] to [4] above, wherein the carrier film is a resin film or a metal foil. [6] The method for manufacturing a printed circuit board according to any one of [1] to [5] above, wherein the protective film is a resin film. [7] The method for manufacturing a printed circuit board according to any one of [1] to [6] above, wherein the photosensitive resin composition further contains (A) a photopolymerizable compound having an ethylenically unsaturated group and an acidic substituent and (B) a thermosetting resin. [8] The method for manufacturing a printed circuit board according to [7] above, wherein the photosensitive resin composition further contains (C) a crosslinking agent. [9] The method for manufacturing a printed circuit board according to [7] or [8], wherein the photosensitive resin composition further contains (I) a photopolymerization initiator.

[10] The method for manufacturing a semiconductor package, comprising mounting a semiconductor element on a printed circuit board obtained by the manufacturing method according to any one of [1] to [9].

[11] A laminated film comprising a carrier film, a photosensitive resin film containing an inorganic filler, and a protective film stacked in that order from bottom to top, wherein the peeling force between the carrier film and the photosensitive resin film is smaller than the peeling force between the protective film and the photosensitive resin film.

[12] The laminated film according to

[11] , wherein the photosensitive resin film has a lower inorganic filler content in the range of 1 to 10 μm thickness from the protective film side than the inorganic filler content in the range of 1 to 10 μm thickness from the carrier film side.

[13] The laminated film according to

[11] or

[12] , wherein the thickness of the photosensitive resin film is 1 to 100 μm.

[0008] According to this disclosure, it is possible to provide a method for manufacturing a printed circuit board that exhibits high adhesive strength to copper plating while using a photosensitive resin composition containing an inorganic filler, and to provide a method for manufacturing a semiconductor package having the printed circuit board, as well as a laminated film.

[0009] This is a scanning electron microscope (SEM) image of the cross-section of the laminate manufactured in Example 1. This is a scanning electron microscope (SEM) image of the cross-section of the laminate manufactured in Comparative Example 1.

[0010] In the numerical ranges described in this disclosure, the upper or lower limits of the numerical range may be replaced with the values ​​shown in the examples. Furthermore, the lower and upper limits of a numerical range can be arbitrarily combined with the lower or upper limits of other numerical ranges. In the notation "AA to BB" for the numerical range, the numbers AA and BB at both ends are included in the numerical range as the lower and upper limits, respectively. In this disclosure, for example, the statement "10 or more" means 10 and numbers greater than 10, and the same applies when the numbers are different. Similarly, for example, the statement "10 or less" means 10 and numbers less than 10, and the same applies when the numbers are different.

[0011] In this disclosure, the content of each component in the photosensitive resin composition means the total content of multiple substances present in the photosensitive resin composition, unless otherwise specified, if there are multiple substances corresponding to each component.

[0012] In this disclosure, "ring-forming carbon number" refers to the number of carbon atoms required to form a ring, and does not include the number of carbon atoms in substituents on the ring. For example, both the cyclohexane skeleton and the methylcyclohexane skeleton have 6 ring-forming carbon atoms. The notation "XX (meth)acrylate" means either or both of XX acrylate and XX methacrylate. Also, "(meth)acryloyl group" means either or both of acryloyl and methacryloyl groups.

[0013] In this disclosure, "resin component" refers to components (A) to (J) described later, and does not include inorganic compounds such as inorganic fillers and pigments. Also, "solid content" refers to components other than the solvent, and components that are liquid at 25°C are also considered to be solid content. In this disclosure, when a "layer" is used, for example, as in an interlayer insulating layer, the term "layer" includes not only solid layers, but also layers that are not solid but have some island-like structures, layers with holes, and layers where the interface with the adjacent layer is unclear. Furthermore, embodiments that arbitrarily combine the items described in this disclosure are also included in this embodiment.

[0014] [Method for Manufacturing Printed Wiring Boards] A method for manufacturing printed wiring boards according to one embodiment of the present disclosure (hereinafter sometimes simply referred to as this embodiment) is a method for manufacturing printed wiring boards that includes the following steps (1) to (4): (1) Applying a photosensitive resin composition containing an inorganic filler to a carrier film to form a photosensitive resin film on the carrier film [hereinafter referred to as the photosensitive resin film formation step (1)]. (2) Installing a protective film on the upper surface of the formed photosensitive resin film [hereinafter referred to as the protective film installation step (2)]. (3) Peeling off the carrier film while the protective film is still attached to the photosensitive resin film [hereinafter referred to as the carrier film peeling step (3)]. (4) Attaching the photosensitive resin film surface exposed by step (3) to a circuit board [hereinafter referred to as the attachment step (4)]. Herein, for convenience, as described above, certain operations may be referred to as "Step XX" in this disclosure, but Step XX is not limited to the embodiments specifically described in this disclosure. The steps of this embodiment will now be described in order.

[0015] (Photosensitive resin film formation process (1)) In the photosensitive resin film formation process (1), a photosensitive resin composition containing an inorganic filler is applied to a carrier film to form a photosensitive resin film on the carrier film. The carrier film is not particularly limited, but examples include polyester resin films such as polyethylene terephthalate (PET) film, polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), polyolefin resin films such as polypropylene and polyethylene; and metal foils such as copper foil and aluminum foil. From the viewpoint of ease of rolling, the carrier film may be a polyester resin film or a PET film. The thickness of the carrier film is not particularly limited, but from the viewpoint of ease of handling, it may be 10 to 3,000 μm, 10 to 2,000 μm, 10 to 1,500 μm, 10 to 1,000 μm, 10 to 600 μm, 10 to 200 μm, or 10 to 100 μm.

[0016] Furthermore, it is preferable that the peeling force between the carrier film and the photosensitive resin film is smaller than the peeling force between the protective film and the photosensitive resin film, which will be described later. This is because, in this embodiment, there is a step of peeling the carrier film from the photosensitive resin film while the protective film, which will be described later, remains attached to the photosensitive resin film. From this viewpoint, the carrier film may, or preferably has a release agent treatment applied to the side on which the photosensitive resin composition is applied. The release agent may be a silicone-based release agent, or a non-silicone-based release agent such as a polyacrylic-based release agent, an amino alkyd-based release agent, or a fluorine-based release agent. A commercially available carrier film can be used as the carrier film that has been treated with a release agent. Examples of commercially available products include Purex A5300, Purex A2400, Purex A3100, Purex A3200, Purex A3700, Purex A5000, Purex A5400, Purex A7100, Purex U3200, Purex UH200 (all manufactured by Toyobo Co., Ltd.), and Unipeel TR1, Unipeel TR5, Unipeel TR6 (all manufactured by Unitika Ltd.).

[0017] There are no particular limitations on the method for applying the photosensitive resin composition to the carrier film, but examples include die coating, printing, spin coating, spray coating, jet dispensing, inkjet, and immersion coating. Among these, die coating, printing, and spin coating may be used from the viewpoint of achieving high uniformity of the coated surface over a large area and from the viewpoint of ease of layer formation, or die coating may be used from the viewpoint of achieving high uniformity of the coated surface over a large area.

[0018] A photosensitive resin film is formed on a carrier film by applying the photosensitive resin composition to the carrier film and then drying it. The drying method is not particularly limited and may be a hot air dryer or a dryer using far-infrared rays, near-infrared rays, etc. The drying temperature is not particularly limited and may be 60 to 150°C, 70 to 140°C, or 90 to 130°C. The drying time is also not particularly limited and may be 0.5 to 60 minutes, 1 to 30 minutes, or 2 to 20 minutes. Drying under the above conditions tends to remove the diluent contained in the photosensitive resin composition.

[0019] The thickness of the photosensitive resin film formed on the carrier film is not particularly limited and may be 1 to 100 μm, 1 to 70 μm, 1 to 50 μm, 2 to 50 μm, 5 to 50 μm, 10 to 50 μm, or 15 to 50 μm.

[0020] (Protective film installation step (2)) In protective film installation step (2), a protective film is installed on the upper surface of the photosensitive resin film formed in photosensitive resin film forming step (1), that is, on the surface opposite to the side in contact with the carrier film. In this embodiment, since a photocuring treatment is performed on the photosensitive resin film from the protective film side in a later step, it is preferable that the protective film has high transparency. From this viewpoint, the protective film is preferably a resin film, more preferably PET, polyethylene, or polypropylene, and even more preferably PET. The total light transmittance of the protective film according to JIS K7361 (1997) is preferably 50% or more from the viewpoint of transparency, may be 50 to 100%, 70 to 100%, or 80 to 95%. The thickness of the protective film is not particularly limited, but from the viewpoint of ease of handling, it may be 10 to 3,000 μm, 10 to 2,000 μm, 10 to 1,500 μm, 10 to 1,000 μm, 10 to 600 μm, 10 to 200 μm, 10 to 100 μm, or 15 to 50 μm.

[0021] As mentioned above, it is preferable that the peeling force between the carrier film and the photosensitive resin film is smaller than the peeling force between the protective film and the photosensitive resin film. Therefore, although not particularly limited, it is preferable that the protective film is not subjected to a release treatment. Although not particularly limited, it is more preferable that the peeling force between the carrier film and the photosensitive resin film is 0.02 to 0.25 N / cm smaller than the peeling force between the protective film and the photosensitive resin film, and may be 0.05 to 0.20 N / cm smaller, 0.05 to 0.18 N / cm smaller, or 0.10 to 0.17 N / cm smaller.

[0022] By the above method, a laminated film is obtained in which a carrier film, a photosensitive resin film containing an inorganic filler, and a protective film are stacked from bottom to top, wherein the peel force between the carrier film and the photosensitive resin film is smaller than the peel force between the protective film and the photosensitive resin film. In the photosensitive resin film of the laminated film, the peel force between the carrier film and the photosensitive resin film is smaller than the peel force between the protective film and the photosensitive resin film by having a smaller proportion of inorganic filler in the range of 1 to 10 μm thickness from the protective film side than the proportion of inorganic filler in the range of 1 to 10 μm thickness from the carrier film side. Details of the photosensitive resin film, such as its thickness and components, are described below.

[0023] (Carrier film peeling step (3)) In carrier film peeling step (3), the carrier film is peeled off while the protective film remains attached to the photosensitive resin film. As mentioned above, this step is made easier to perform by making the peeling force between the carrier film and the photosensitive resin film smaller than the peeling force between the protective film and the photosensitive resin film. The method of peeling off the carrier film is not particularly limited, but examples include (i) a method of peeling off the leading edge of the carrier film by hand, and (ii) a method of attaching the leading edge of the carrier film to the roll of a laminator and winding it up by rotating the roll.

[0024] In the conventional technology, a carrier film that has not been treated with a mold release agent is used, and a protective film that has been treated with a mold release agent is used. Instead of the carrier film peeling step (3), the protective film is peeled off from the photosensitive resin film while the carrier film is still attached, and then the exposed photosensitive resin film is attached to the circuit board. In the conventional technology method, it was found that when copper plating is applied to the interlayer insulating layer made of photosensitive resin film in the manufacturing process of the printed circuit board, the adhesive strength between the interlayer insulating layer and the copper plating tends to be low. However, this problem was resolved with this embodiment. Further investigation by the inventors revealed that in the photosensitive resin film forming step (1), the inorganic filler tends to settle when the photosensitive resin film is formed, and the density of the inorganic filler is high in the lower part of the photosensitive resin film (see Figure 1). On the other hand, it was found that the density of the inorganic filler is low in the upper part of the photosensitive resin film (see Figure 1). Therefore, it can be seen that applying copper plating to the surface on the side with lower density of inorganic filler increased the adhesive strength between the interlayer insulating layer and the copper plating. From this, it can be inferred that if the inorganic filler is excessively present on the surface of the interlayer insulating layer made of photosensitive resin film, the adhesive area between the resin component and the copper plating will be small, which will lead to a decrease in the adhesive strength between the interlayer insulating layer and the copper plating. In this embodiment, the lower part of the photosensitive resin film is attached to the circuit board and the copper plating is applied to the upper part of the photosensitive resin film, so the adhesive strength between the interlayer insulating layer and the copper plating was increased. Therefore, from the viewpoint of the adhesive strength between the interlayer insulating layer made of photosensitive resin film and the copper plating, it can be said that in the photosensitive resin film formed in the photosensitive resin film forming process (1), it is preferable that the content ratio of inorganic filler in the range of 1 to 10 μm (preferably 1 to 5 μm) from the protective film side is smaller than the content ratio of inorganic filler in the range of 1 to 10 μm (preferably 1 to 5 μm) from the carrier film side.

[0025] (Bonding process (4)) In bonding process (4), the photosensitive resin film surface exposed by the carrier film peeling process (3) is bonded to the circuit board. The photosensitive resin film surface exposed by the carrier film peeling process (3) is the side with a higher density of inorganic filler. The photosensitive resin film may be bonded to one side of the circuit board, or it may be bonded to both sides.

[0026] While there are no particular restrictions on the method of application, using a laminator is preferred. Examples of laminators include vacuum applicators manufactured by Nikko Materials Co., Ltd. and vacuum pressure laminators manufactured by Japan Steel Works Ltd.

[0027] The lamination can be carried out, for example, by preheating the photosensitive resin film and circuit board as needed, at a pressure of 70 to 130°C, a pressure of 0.1 to 1.0 MPa, and under reduced pressure of 20 mmHg (26.7 hPa) or less, but is not limited to these conditions. The lamination method may be batch or continuous on a roll. Finally, by cooling the photosensitive resin film laminated to the circuit board to around 25°C, the photosensitive resin film becomes an interlayer insulating layer. Since the protective film remains attached to the photosensitive resin film, it may be peeled off at this point, but as will be described later, the protective film may also be peeled off after exposure.

[0028] This embodiment may further include the following steps.

[0029] (Photovia Formation Process (5)) In the photovia formation process (5), at least a portion of the photosensitive resin film laminated to the circuit board is exposed to light, and then developed. The exposure causes the portion irradiated with the active light to photocur, forming a pattern. There are no particular restrictions on the exposure method. For example, a method may be employed in which the active light is irradiated in an image-like manner by passing it through a negative or positive mask pattern called artwork (mask exposure method), or a method may be employed in which the active light is irradiated in an image-like manner by a direct drawing exposure method such as LDI (Laser Direct Imaging) exposure or DLP (Digital Light Processing) exposure. Known light sources can be used as the light source for the active light. Specifically, examples of light sources include carbon arc lamps, mercury vapor arc lamps, high-pressure mercury lamps, xenon lamps, gas lasers such as argon lasers; solid-state lasers such as YAG lasers; and semiconductor lasers that effectively emit ultraviolet or visible light. The exposure dose is appropriately selected depending on the light source used and the thickness of the photosensitive resin film. For example, in the case of ultraviolet irradiation from a high-pressure mercury lamp, for a photosensitive resin film thickness of 1 to 100 μm, the exposure dose is typically 10 to 1,000 mJ / cm². ２ A suitable level is 50-700 mJ / cm². ２ More preferably, 150-550 mJ / cm ２ That is even more preferable.

[0030] During development, the uncured portion of the photosensitive resin film is removed from the substrate, and the photocured portion is formed on the substrate as an interlayer insulating layer. If a protective film is present on the photosensitive resin film, the protective film may be removed before removing the unexposed portion (development), if necessary. There are two development methods: wet development and dry development. Either method may be used, but wet development is widely used, and wet development can also be used in this embodiment. In the case of wet development, development is performed using a developer solution corresponding to the photosensitive resin composition and a known development method. Development methods include the dip method, paddle method, spray method, brushing, slapping, scraping, and oscillating immersion method. Among these, the spray method is preferred from the viewpoint of improving the resolution of vias, and among spray methods, the high-pressure spray method is more preferred. Development may be performed using one method, or two or more methods may be combined. The composition of the developer solution is appropriately selected according to the composition of the photosensitive resin composition. Examples include alkaline aqueous solutions, aqueous developers, and organic solvent developers, and among these, alkaline aqueous solutions are preferred.

[0031] In the photovia formation process (5), after exposure and development, 0.2 to 10 J / cm ２ Degree (preferably 0.5 to 5 J / cm) ２ The interlayer insulating layer may be further cured, and is preferable, by performing a post-UV cure with an exposure dose of ) and a post-thermal cure at a temperature of about 60 to 250°C (preferably 120 to 200°C) as needed. An interlayer insulating layer having vias is formed by the above method. There are no particular restrictions on the shape of the vias; in terms of cross-sectional shape, examples include squares and inverted trapezoids (trapezoids where the top side is longer than the bottom side), and in terms of shape when viewed from the front (the direction in which the via bottom is visible), examples include circles and squares. In the photolithography method for forming vias in this embodiment, vias with an inverted trapezoidal cross-sectional shape (where the top side is longer than the bottom side) can be formed, which is preferable because it improves the adhesion of the copper plating to the via wall surface.

[0032] The size (diameter) of the vias formed by this process can be less than 40 μm, and can even be 35 μm or less, 30 μm or less, 25 μm or less, or 20 μm or less, making it smaller than the size of vias produced by laser processing. There is no particular lower limit to the size (diameter) of the vias formed by this process, but it may be 5 μm or more, 10 μm or more, or 15 μm or more. However, the size (diameter) of the vias formed by this process is not limited to less than 40 μm, and may be arbitrarily selected within the range of 5 to 300 μm, 10 to 200 μm, 15 to 100 μm, or 20 to 80 μm.

[0033] (Roughening process (6)) In roughening process (6), the surfaces of the vias and the interlayer insulating layer are roughened. The roughening process forms fine irregularities as anchors on the surfaces of the vias and the interlayer insulating layer. The surface roughness (Ra) of the interlayer insulating layer after roughening is preferably 1.0 μm or less, more preferably 0.70 μm or less, even more preferably 0.60 μm or less, particularly preferably 0.50 μm or less, and most preferably 0.40 μm or less, from the viewpoint of miniaturizing the wiring, and there is no particular limit on the lower limit, which may be 0.01 μm or more, 0.05 μm or more, or 0.10 μm or more. In other words, the surface roughness (Ra) of the interlayer insulating layer after roughening may be 0.01 to 1.0 μm. In this disclosure, the surface roughness (Ra) is the result of measurement using a high-performance non-contact three-dimensional surface roughness measurement system (Wyko NT9100, manufactured by Bruker Japan Co., Ltd.), and more specifically, the value measured by the method described in the examples.

[0034] There are no particular limitations on the roughening treatment method, and known roughening treatment methods for vias and interlayer insulating layers can be used. While there are no particular limitations on the roughening treatment method, examples include methods using a roughening solution and methods using dry etching. Here, the method using a roughening solution is also called wet etching.

[0035] As the roughening solution, an oxidizing agent can be used. Examples of the oxidizing agent include an alkaline permanganate solution obtained by dissolving potassium permanganate, sodium permanganate, etc. in an aqueous solution of sodium hydroxide, dichromate, ozone, hydrogen peroxide - sulfuric acid, nitric acid, etc. The concentration of the permanganate in the alkaline permanganate solution is preferably 5 to 10% by mass. Examples of commercially available oxidizing agents include alkaline permanganate solutions such as Concentrate Compact CP and Dosing Solution Security Guard P (both manufactured by Atotech Japan Co., Ltd.). In addition, when smears occur in the photovia formation step (5), the smears may be removed with the roughening solution. The roughening treatment and the removal of smears (desmearing) can be performed simultaneously.

[0036] When performing using the roughening solution, preferably, after swelling treatment of the via surface and the surface of the interlayer insulating layer, roughening treatment of the via surface and the surface of the interlayer insulating layer is performed. Here, a commercially available swelling solution can be used for the swelling treatment. Examples of the swelling solution include an alkaline solution, a surfactant solution, etc., and an alkaline solution is preferably used. Examples of the alkaline solution include a sodium hydroxide solution, a potassium hydroxide solution, etc. Examples of commercially available swelling solutions include Swelling Dip Security Guard P, Swelling Dip Security Guard SBU (both manufactured by Atotech Japan Co., Ltd.), etc. There are no particular restrictions on the time and temperature of the swelling treatment, but preferably it is 50 to 90 °C, more preferably 60 to 80 °C, preferably 1 to 20 minutes, more preferably 3 to 15 minutes, and even more preferably 3 to 8 minutes.

[0037] Furthermore, after the swelling treatment and the roughening treatment, a water washing treatment may be performed as needed. There are no particular restrictions on the time and temperature of the water washing treatment, but it is preferably 5 to 70°C, more preferably 15 to 60°C, even more preferably 30 to 60°C, preferably 0.1 to 10 minutes, and more preferably 0.5 to 7 minutes. The water washing treatment may be a combination of so-called "water storage washing" where water is simply stored and so-called "flowing water washing" where water is flowed, or either one alone may be performed, but it is preferable to perform at least flowing water washing, and it is more preferable to perform both water storage washing and flowing water washing.

[0038] Examples of the aforementioned dry etching include RIE (Reactive Ion Etching), and examples of RIE include dry etching using reactive gases and dry etching using plasma. Among these, dry etching using plasma is preferred. For dry etching using plasma, commercially available plasma etching equipment can be used. The conditions for dry etching using plasma are not particularly limited, but preferably oxygen plasma is used, preferably with an output of 100 to 500 W, more preferably with an output of 200 to 400 W. There are no particular restrictions on the time and temperature of dry etching, but preferably 5 to 40°C, more preferably 15 to 30°C, preferably 0.1 to 10 minutes, more preferably 0.5 to 7 minutes.

[0039] (Neutralization Process (7)) In the neutralization process (7), the roughened interlayer insulating layer is treated with an acidic solution. The acidic solution is not particularly limited, and examples thereof include an aqueous sulfuric acid solution, an aqueous hydrochloric acid solution, an aqueous sodium persulfate solution, an aqueous ammonium persulfate solution, an aqueous potassium persulfate solution, etc. The acidic solution preferably contains an aqueous sulfuric acid solution or an aqueous hydrochloric acid solution, more preferably contains an aqueous sulfuric acid solution, and even more preferably is an aqueous sulfuric acid solution. The concentration of the aqueous sulfuric acid solution is preferably 5 to 100 ml / L, more preferably 10 to 80 ml / L, even more preferably 15 to 50 ml / L, and may be 10 to 30 ml / L, or may be 35 to 80 ml / L, or may be 35 to 60 ml / L. The concentration of the aqueous hydrochloric acid solution is preferably 5 to 100 g / L, more preferably 10 to 80 g / L, even more preferably 15 to 50 g / L, and may be 10 to 30 ml / L, or may be 35 to 80 ml / L, or may be 35 to 60 ml / L. Note that although not particularly limited, the acidic solution preferably does not have toxicity (e.g., hydrofluoric acid).

[0040] The temperature when treating the interlayer insulating layer with the acidic solution is preferably 15 to 80°C, more preferably 20 to 75°C, even more preferably 25 to 70°C, and may be 30 to 70°C, or may be 40 to 60°C. The treatment time with the acidic solution is not particularly limited, but is preferably 0.1 to 40 minutes, more preferably 0.3 to 35 minutes, even more preferably 1 to 30 minutes, particularly preferably 1 to 20 minutes, and most preferably 1 to 10 minutes. There is no particular limitation on the method of treating the interlayer insulating layer with the acidic solution. For example, (1) a method of immersing a substrate having an interlayer insulating layer in an acidic solution and, if necessary, rocking the substrate having the interlayer insulating layer; (2) a method of immersing a substrate having an interlayer insulating layer in an acidic solution and, if necessary, stirring the acidic solution; (3) a method of spraying an acidic solution onto the interlayer insulating layer, etc. can be mentioned.

[0041] After treatment with the acidic solution, a water rinse may be performed as needed. There are no particular restrictions on the time and temperature of the water rinse, but it is preferably 5 to 40°C, more preferably 15 to 30°C, and preferably 0.1 to 10 minutes, more preferably 0.5 to 7 minutes. The water rinse may be a combination of rinsing with stored water and rinsing with running water, or either one alone may be performed, but it is preferable to perform at least rinsing with running water, and more preferably to perform both rinsing with stored water and rinsing with running water.

[0042] (Circuit Pattern Formation Process (8)) The circuit pattern formation process (8) is a process of forming a circuit pattern on the interlayer insulating layer. From the viewpoint of forming fine wiring, it is preferable to perform the circuit pattern formation by a semi-additive process. The semi-additive process forms the circuit pattern and simultaneously provides conductivity to the vias. In the semi-additive process, first, a seed layer is formed by electroless copper plating using a palladium catalyst or the like on the via bottom, via wall surface, and the entire surface of the interlayer insulating layer. The seed layer is for forming a power supply layer for electroplating copper, and is preferably formed to a thickness of about 0.1 to 2.0 μm. If the thickness of the seed layer is 0.1 μm or more, it tends to suppress a decrease in connection reliability during electroplating copper, and if it is 2.0 μm or less, it does not need to increase the amount of etching when flash etching the seed layer between wirings, and tends to suppress damage to the wiring during etching.

[0043] As a pretreatment before seed layer formation, a cleaner treatment (also called a conditioner treatment) and a water wash treatment, as well as a soft etching and a water wash treatment, may be performed as needed. The cleaner treatment is preferably performed at 40 to 80°C, more preferably 50 to 70°C, for preferably 0.1 to 10 minutes, more preferably 0.5 to 7 minutes, using a commercially available alkaline cleaner (conditioner solution). The water wash treatment after the cleaner treatment will be described in the same way as the water wash treatment described above, and the preferred embodiments will also be the same. Soft etching can be performed by treating with sodium persulfate and sulfuric acid, or ammonium persulfate and sulfuric acid, preferably at 10 to 40°C, more preferably 20 to 35°C, for preferably 0.1 to 3 minutes, more preferably 0.3 to 1 minute. The water wash treatment after soft etching will be described in the same way as the water wash treatment described above, and the preferred embodiments will also be the same.

[0044] The electroless copper plating process is carried out by depositing metallic copper on the surfaces of vias and interlayer insulating layers through a reaction between copper ions and a reducing agent. The electroless plating method and the electrolytic plating method can be any known method and are not particularly limited. Commercially available electroless copper plating solutions can be used, including "MSK-DK" from Attec Japan Co., Ltd. and the "Surupap PEA series" from Uemura Kogyo Co., Ltd.

[0045] After the electroless copper plating process described above, a dry film resist is heat-pressed onto the electroless copper plating using a roll laminator. The thickness of the dry film resist must be greater than the wiring height after electroplating, and from this viewpoint, a dry film resist with a thickness of 5 to 30 μm is preferred. As the dry film resist, the "Photec" series manufactured by Resonaq Corporation is used. After heat-pressing the dry film resist, for example, the dry film resist is exposed through a mask on which the desired wiring pattern is drawn. Exposure can be performed using the same apparatus and light source as those used when forming vias on the photosensitive resin film. After exposure, the dry film resist is developed using an alkaline aqueous solution, and the unexposed areas are removed to form the resist pattern 106. After this, if necessary, the development residue of the dry film resist may be removed using plasma or the like. After development, the copper circuit layer (circuit pattern) and via filling are performed by electroplating.

[0046] After electroplating copper, the dry film resist is removed using an alkaline aqueous solution or an amine-based stripping agent. After removing the dry film resist, the seed layer between the wiring is removed (flash etching). Flash etching is performed using an acidic solution such as sulfuric acid and hydrogen peroxide, and an oxidizing solution. After flash etching, palladium and other materials adhering to the areas between the wiring are removed as needed. Palladium removal can preferably be performed using an acidic solution such as nitric acid or hydrochloric acid.

[0047] After peeling off the dry film resist or after the flash etching process, a post-bake treatment is preferably performed. The post-bake treatment allows unreacted thermosetting components to be sufficiently thermoset, and further tends to improve insulation reliability, curing characteristics, and adhesion strength to copper plating. Although the thermosetting conditions vary depending on the type of resin composition, a curing temperature of 150 to 240°C and a curing time of 15 to 100 minutes are preferable. The post-bake treatment completes the manufacturing process of the printed circuit board by the photovia method, and by repeating this process according to the required number of interlayer insulating layers, a multilayer printed circuit board can be manufactured. Then, preferably, a solder resist layer is formed on the outermost layer.

[0048] Next, an example of a photosensitive resin composition containing an inorganic filler that can be used in this embodiment will be described, but the photosensitive resin composition is not limited to the one described below. [Photosensitive Resin Composition] The photosensitive resin composition used in this embodiment is a photosensitive resin composition containing an inorganic filler. Because the photosensitive resin composition contains an inorganic filler, in the photosensitive resin film forming step (1), the inorganic filler tends to be present in a settled state in the photosensitive resin film formed from the photosensitive resin composition. This tendency is particularly pronounced when the specific gravity of the diluent contained in the photosensitive resin composition is small. The diluent will be described later.

[0049] <Inorganic Filler> The photosensitive resin composition tends to have a lower coefficient of thermal expansion, heat resistance, and flame retardancy when it contains an inorganic filler. For convenience, in this disclosure, the inorganic filler may be referred to as component (E) and called (E) inorganic filler. The inorganic filler is not particularly limited, but examples include silica, alumina, titanium oxide, mica, beryllium, barium titanate, potassium titanate, strontium titanate, calcium titanate, aluminum carbonate, aluminum hydroxide, aluminum silicate, calcium silicate, magnesium silicate, silicon nitride, boron nitride, clay (fired clay, etc.), molybdate compounds (zinc molybdate, etc.), aluminum borate, silicon carbide, etc. One type of inorganic filler may be used alone, or two or more types may be used in combination. Among these, silica, alumina, and mica are preferred as inorganic fillers from the viewpoint of coefficient of thermal expansion, heat resistance, and flame retardancy, silica and alumina are more preferred, and silica is even more preferred. Examples of silica include crushed silica, fumed silica, and fused silica (fused spherical silica).

[0050] The volume-average particle diameter of the inorganic filler is not particularly limited, but is preferably 0.01 to 20 μm, more preferably 0.1 to 10 μm, even more preferably 0.2 to 1 μm, and particularly preferably 0.3 to 0.8 μm. Hereinafter, the volume-average particle diameter is determined by measuring particles dispersed in a solvent with a refractive index of 1.38 using a submicron particle analyzer "N5" (manufactured by Beckman Coulter, Inc.) in accordance with ISO 13321, and is determined as the particle diameter corresponding to 50% of the cumulative value (volume basis) in the particle size distribution.

[0051] (Content of inorganic filler) The content of inorganic filler in the photosensitive resin composition is not particularly limited, but may be 5 to 60 volume%, 10 to 55 volume%, 15 to 50 volume%, 20 to 50 volume%, or 20 to 45 volume%, based on the total solid content of the photosensitive resin composition. When the inorganic filler content is above the lower limit, the low coefficient of thermal expansion, heat resistance, and flame retardancy tend to be further improved. When the inorganic filler content is below the upper limit, the tendency for the photosensitive resin film to tear easily and become brittle tends to be suppressed. In addition, when the inorganic filler content is within the above range, the inorganic filler tends to settle downwards in the photosensitive resin film, which tends to decrease the density of the inorganic filler in the upper part of the photosensitive resin film.

[0052] The photosensitive resin composition may further contain (A) a photopolymerizable compound having an ethylenically unsaturated group and an acidic substituent, and (B) a thermosetting resin. The components (A) and (B) will be described in detail below, followed by a detailed description of the other components.

[0053] <(A) Photopolymerizable compound having an ethylenically unsaturated group and an acidic substituent> Component (A) is a photopolymerizable compound having an ethylenically unsaturated group and an acidic substituent. Component (A) may be used alone or in combination of two or more types.

[0054] Component (A) is a compound that exhibits photopolymerizability, particularly radical polymerization, because it has an ethylenically unsaturated group. Examples of ethylenically unsaturated groups in component (A) include photopolymerizable functional groups such as vinyl group, allyl group, propargyl group, butenyl group, ethynyl group, phenylethynyl group, maleimide group, nadiimide group, and (meth)acryloyl group. Among these, the (meth)acryloyl group is preferred from the viewpoint of reactivity and via resolution.

[0055] Component (A) has an acidic substituent from the viewpoint of enabling alkaline development. Examples of acidic substituents of component (A) include carboxyl groups, sulfonic acid groups, and phenolic hydroxyl groups. Among these, carboxyl groups are preferred from the viewpoint of via resolution. The acid value of component (A) is preferably 20 to 200 mg KOH / g, more preferably 40 to 180 mg KOH / g, even more preferably 70 to 150 mg KOH / g, and particularly preferably 90 to 120 mg KOH / g. When the acid value of component (A) is above the lower limit, the solubility of the photosensitive resin film in dilute alkaline solutions tends to be excellent, and when it is below the upper limit, the dielectric constant tends to be excellent. The acid value of component (A) can be calculated from the amount of potassium hydroxide aqueous solution required for neutralization. Two or more components (A) with different acid values ​​may be used in combination, in which case it is preferable that the weighted average acid value of the two or more components (A) is within any of the above ranges.

[0056] The weight-average molecular weight (Mw) of component (A) is preferably 600 to 30,000, more preferably 800 to 25,000, even more preferably 1,000 to 18,000, even more preferably 1,000 to 8,000, particularly preferably 1,200 to 5,000, and most preferably 1,200 to 3,500. When the weight-average molecular weight (Mw) of component (A) is within the above range, the adhesion strength to copper plating, heat resistance, and insulation reliability tend to be excellent. Hereinafter, the weight-average molecular weight is the value obtained by converting to standard polystyrene equivalent by gel permeation chromatography (GPC) using tetrahydrofuran as a solvent.

[0057] Component (A) preferably has an alicyclic skeleton from the viewpoint of reducing the relative permittivity, but it may not have an alicyclic skeleton. The alicyclic skeleton of component (A) is preferably an alicyclic skeleton having 5 to 20 ring-forming carbon atoms, more preferably an alicyclic skeleton having 5 to 18 ring-forming carbon atoms, further preferably an alicyclic skeleton having 6 to 18 ring-forming carbon atoms, particularly preferably an alicyclic skeleton having 8 to 14 ring-forming carbon atoms, and most preferably an alicyclic skeleton having 8 to 12 ring-forming carbon atoms, from the viewpoints of via resolution, adhesion strength to copper plating, and electrical insulation reliability. Further, from the viewpoints of via resolution, adhesion strength to copper plating, and electrical insulation reliability, the alicyclic skeleton preferably consists of two or more rings, more preferably consists of 2 to 4 rings, and even more preferably consists of 3 rings. Examples of the alicyclic skeleton of two or more rings include a norbornane skeleton, a decalin skeleton, a bicycloundecane skeleton, a saturated dicyclopentadiene skeleton, and the like. Among these, from the viewpoints of via resolution, adhesion strength to copper plating, and electrical insulation reliability, a saturated dicyclopentadiene skeleton is preferable. From the same viewpoint, component (A) preferably has an alicyclic skeleton represented by the following general formula (A-1).

[0058] (In the formula, R Ａ１ represents an alkyl group having 1 to 12 carbon atoms, and may be substituted anywhere in the alicyclic skeleton. m １ is an integer of 0 to 6. * is a bonding site to another structure.)

[0059] In the general formula (A-1), the alkyl group having 1 to 12 carbon atoms represented by R Ａ１ is preferably an alkyl group having 1 to 6 carbon atoms, more preferably an alkyl group having 1 to 3 carbon atoms, and even more preferably a methyl group. m １ is an integer of 0 to 6, preferably an integer of 0 to 2, and more preferably 0. When m １ is an integer of 2 to 6, the plurality of R Ａ１ may be the same or different from each other. Further, the plurality of R Ａ１The carbon atoms may be substituted on the same carbon atom or on different carbon atoms, to the extent possible. * is a bonding site to another structure, and may be bonded to any carbon atom on the alicyclic skeleton, but it is preferable that they are bonded to the carbon atom at the site indicated by 1 or 2 in the general formula (A-1') below, and to the carbon atom at the site indicated by either 3 or 4.

[0060] (In the formula, R Ａ１ , m １ And * are the same as those in the general formula (A-1) above.

[0061] Furthermore, from the viewpoint of via resolution and adhesion strength to copper plating, component (A) is preferably an "acid-modified ethylenically unsaturated group-containing resin" obtained by reacting a compound obtained by modifying (a1) epoxy resin with (a2) an ethylenically unsaturated group-containing organic acid [hereinafter sometimes referred to as component (A')] with (a3) ​​a polybasic acid anhydride containing a saturated or unsaturated group. Here, "acid modification" in the acid-modified ethylenically unsaturated group-containing resin means having an acidic substituent. Below, preferred embodiments of component (A) obtained from (a1) epoxy resin, (a2) ethylenically unsaturated group-containing organic acid, and (a3) ​​a polybasic acid anhydride containing a saturated or unsaturated group will be described.

[0062] (a1) Epoxy resin) The epoxy resin (a1) is preferably an epoxy resin having two or more epoxy groups. The epoxy resin (a1) may be used alone or in combination of two or more types. The epoxy resin (a1) is classified into glycidyl ether type epoxy resin, glycidylamine type epoxy resin, glycidyl ester type epoxy resin, etc. Among these, the glycidyl ether type epoxy resin is preferred.

[0063] (a1) Epoxy resins can be classified into various types based on differences in their main skeleton, including epoxy resins with an alicyclic skeleton, novolac-type epoxy resins, bisphenol-type epoxy resins, aralkyl-type epoxy resins, and other epoxy resins. Among these, epoxy resins with an alicyclic skeleton and novolac-type epoxy resins are preferred.

[0064] -Epoxy resin having an alicyclic skeleton- The alicyclic skeleton of the epoxy resin having an alicyclic skeleton will be described in the same way as the alicyclic skeleton of component (A) described above, and the preferred embodiments will also be the same.

[0065] As the epoxy resin having an alicyclic skeleton, commercially available products may be used, such as XD-1000 (manufactured by Nippon Kayaku Co., Ltd.) and EPICLON HP-7200 (manufactured by DIC Corporation).

[0066] -Novolac-type epoxy resins- Examples of novolac-type epoxy resins include bisphenol novolac-type epoxy resins such as bisphenol A novolac-type epoxy resin, bisphenol F novolac-type epoxy resin, and bisphenol S novolac-type epoxy resin; phenol novolac-type epoxy resin, cresol novolac-type epoxy resin, biphenyl novolac-type epoxy resin, naphthol novolac-type epoxy resin, etc. There are no particular limitations on the novolac-type epoxy resin, but cresol novolac-type epoxy resin is preferred.

[0067] Examples of bisphenol-type epoxy resins include bisphenol A-type epoxy resin, bisphenol F-type epoxy resin, bisphenol S-type epoxy resin, and 3,3',5,5'-tetramethyl-4,4'-diglycidyloxydiphenylmethane. Examples of aralkyl-type epoxy resins include phenol aralkyl-type epoxy resin, biphenyl aralkyl-type epoxy resin, and naphthol aralkyl-type epoxy resin. Other epoxy resins include stilbene-type epoxy resin, naphthalene skeleton-containing epoxy resin, biphenyl-type epoxy resin, dihydroanthracene-type epoxy resin, cyclohexanedimethanol-type epoxy resin, trimethylol-type epoxy resin, aliphatic chain epoxy resin, heterocyclic epoxy resin, spiro-ring-containing epoxy resin, and rubber-modified epoxy resin.

[0068] (a2) Organic acid containing an ethylenically unsaturated group (a2) As the organic acid containing an ethylenically unsaturated group (a2), a monocarboxylic acid containing an ethylenically unsaturated group is preferred. The ethylenically unsaturated group that component (a2) has is the same as that listed as the ethylenically unsaturated group that component (A) has. Examples of component (a2) include acrylic acid derivatives such as acrylic acid, acrylic acid dimers, methacrylic acid, β-furfurylacrylic acid, β-styrylacrylic acid, cinnamic acid, crotonic acid, and α-cyanocinnamic acid; semi-ester compounds which are reaction products of hydroxyl group-containing acrylates and dibasic acid anhydrides; and semi-ester compounds which are reaction products of vinyl group-containing monoglycidyl ethers or vinyl group-containing monoglycidyl esters and dibasic acid anhydrides. Component (a2) may be used alone or in combination of two or more.

[0069] The aforementioned semi-ester compound is obtained by reacting one or more ethylenically unsaturated group-containing compounds selected from the group consisting of hydroxyl group-containing acrylates, vinyl group-containing monoglycidyl ethers, and vinyl group-containing monoglycidyl esters with a dibasic acid anhydride. In this reaction, it is preferable to react the ethylenically unsaturated group-containing compound and the dibasic acid anhydride in equimolar amounts.

[0070] Examples of hydroxyl group-containing acrylates used in the synthesis of the aforementioned semi-ester compounds include hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, polyethylene glycol mono(meth)acrylate, trimethylolpropanedi(meth)acrylate, pentaerythritol tri(meth)acrylate, and dipentaerythritol penta(meth)acrylate. Examples of vinyl group-containing monoglycidyl ethers include glycidyl (meth)acrylate.

[0071] The dibasic acid anhydride used in the synthesis of the aforementioned semi-ester compound may contain a saturated group or an unsaturated group. Examples of dibasic acid anhydrides include succinic anhydride, maleic anhydride, tetrahydrophthalic anhydride, phthalic anhydride, methyltetrahydrophthalic anhydride, ethyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, ethylhexahydrophthalic anhydride, and itaconic anhydride.

[0072] In the reaction between component (a1) and component (a2), the amount of component (a2) used per equivalent of epoxy group of component (a1) is preferably 0.6 to 1.05 equivalents, more preferably 0.7 to 1.02 equivalents, and even more preferably 0.8 to 1.0 equivalents. By reacting component (a1) and component (a2) in the above ratio, the photopolymerizability of component (A) is improved, and the resolution of vias in the resulting photosensitive resin composition tends to improve.

[0073] As described above, when an ethylenically unsaturated monocarboxylic acid is used as component (a2), component (A') obtained by reacting component (a1) and component (a2) will have a hydroxyl group formed by a ring-opening addition reaction between the epoxy group of component (a1) and the carboxyl group of component (a2). Next, by further reacting component (a3) ​​with component (A'), an acid-modified ethylenically unsaturated resin can be obtained in which the hydroxyl groups of component (A') (including the hydroxyl groups originally present in component (a1)) and the acid anhydride group of component (a3) ​​are semi-esterified.

[0074] (a3) Polybasic acid anhydride The (a3) ​​component may contain saturated groups or unsaturated groups. Examples of (a3) ​​components include succinic anhydride, maleic anhydride, tetrahydrophthalic anhydride, phthalic anhydride, methyltetrahydrophthalic anhydride, ethyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, ethylhexahydrophthalic anhydride, itaconic anhydride, etc. Among these, tetrahydrophthalic anhydride is preferred from the viewpoint of via resolution. The (a3) ​​component may be used alone or in combination of two or more.

[0075] When the photosensitive resin composition contains component (A), the content of component (A) is not particularly limited, but from the viewpoint of heat resistance, dielectric constant and chemical resistance, it is preferably 10 to 80% by mass, more preferably 15 to 75% by mass, even more preferably 25 to 70% by mass, particularly preferably 35 to 70% by mass, and most preferably 45 to 70% by mass, based on the total amount of resin components of the photosensitive resin composition.

[0076] <(B) Thermosetting Resin> Component (B) is a thermosetting resin. Component (B) does not contain component (A). The inclusion of thermosetting resin (B) in the photosensitive resin composition tends to improve heat resistance in addition to improving adhesion strength and insulation reliability with copper plating. Examples of thermosetting resins include epoxy resins, phenolic resins, unsaturated imide resins, cyanate resins, isocyanate resins, benzoxazine resins, oxetane resins, amino resins (e.g., melamine resins), unsaturated polyester resins, allyl resins, dicyclopentadiene resins, and silicone resins. Furthermore, the composition is not limited to these, and known thermosetting resins can be used. Among these, epoxy resins are preferred from the viewpoint of adhesion strength with copper plating, insulation reliability, and heat resistance. Component (B) may be used alone or two or more may be used in combination.

[0077] The epoxy resin is preferably one having two or more epoxy groups. Epoxy resins are classified into glycidyl ether type epoxy resins, glycidyl amine type epoxy resins, glycidyl ester type epoxy resins, etc. Among these, glycidyl ether type epoxy resins are preferred.

[0078] Furthermore, epoxy resins are classified into various types based on differences in their main skeleton, and each of the above types of epoxy resins is further classified as follows: Specifically, bisphenol-based epoxy resins such as bisphenol A type epoxy resin, bisphenol F type epoxy resin, and bisphenol S type epoxy resin; bisphenol-based novolac type epoxy resins such as bisphenol A novolac type epoxy resin and bisphenol F novolac type epoxy resin; novolac type epoxy resins other than the above bisphenol-based novolac type epoxy resins, such as phenol novolac type epoxy resin, cresol novolac type epoxy resin, and biphenyl novolac type epoxy resin; phenol aralkyl type epoxy resin; stilbene type epoxy resin; naphtho These epoxy resins are classified into categories such as: naphthalene skeleton-containing epoxy resins such as runovolac type epoxy resins, naphthol type epoxy resins, naphthol aralkyl type epoxy resins, and naphthylene ether type epoxy resins; biphenyl type epoxy resins; biphenyl aralkyl type epoxy resins; xylylene type epoxy resins; dihydroanthracene type epoxy resins; alicyclic epoxy resins such as saturated dicyclopentadiene type epoxy resins; heterocyclic epoxy resins; spiro ring-containing epoxy resins; cyclohexanedimethanol type epoxy resins; trimethylol type epoxy resins; aliphatic chain epoxy resins; and rubber-modified epoxy resins.

[0079] Among these, the epoxy resin is preferably selected from the group consisting of bisphenol-based epoxy resins, naphthalene skeleton-containing epoxy resins, and biphenyl aralkyl type epoxy resins, particularly from the viewpoint of heat resistance, electrical insulation reliability, developability, and adhesive strength with copper plating, and more preferably includes at least one selected from the group consisting of naphthalene skeleton-containing epoxy resins and biphenyl aralkyl type epoxy resins.

[0080] When the photosensitive resin composition contains component (B), the content of component (B) is not particularly limited, but from the viewpoint of insulation reliability, dielectric constant, heat resistance and adhesion strength with copper plating, it is preferably 1 to 50% by mass, more preferably 5 to 30% by mass, even more preferably 10 to 25% by mass, and most preferably 15 to 25% by mass, based on the total amount of resin components of the photosensitive resin composition.

[0081] <(C) Crosslinking Agent> The photosensitive resin composition may further contain a crosslinking agent as component (C). Preferably, the crosslinking agent has two or more ethylenically unsaturated groups and does not have acidic substituents. The crosslinking agent reacts with the ethylenically unsaturated groups of component (A) to increase the crosslink density of the photosensitive resin film after curing. Therefore, the heat resistance and dielectric constant of the photosensitive resin composition tend to be further improved by containing a crosslinking agent. Component (C) may be used alone or in combination of two or more types.

[0082] Component (C) may include a difunctional monomer having two ethylenically unsaturated groups, and a polyfunctional monomer having three or more ethylenically unsaturated groups. Component (C) preferably contains the aforementioned polyfunctional monomer. The ethylenically unsaturated groups of component (C) may be the same as those of component (A), and the preferred groups are also the same.

[0083] Examples of the aforementioned difunctional monomers include aliphatic di(meth)acrylates such as trimethylolpropane di(meth)acrylate, polypropylene glycol di(meth)acrylate, and polyethylene glycol di(meth)acrylate; di(meth)acrylates having an alicyclic skeleton such as dicyclopentadiene di(meth)acrylate and tricyclodecanedimethanol di(meth)acrylate; and aromatic di(meth)acrylates such as 2,2-bis(4-(meth)acryloxypolyethoxypolypropoxyphenyl)propane and bisphenol A diglycidyl ether di(meth)acrylate. Among these, from the viewpoint of obtaining a lower dielectric constant, di(meth)acrylates having an alicyclic skeleton are preferred, and tricyclodecanedimethanol diacrylate is more preferred.

[0084] Examples of the polyfunctional monomers include (meth)acrylate compounds having a trimethylolpropane-derived skeleton such as trimethylolpropane tri(meth)acrylate; (meth)acrylate compounds having a tetramethylolmethane-derived skeleton such as tetramethylolmethane tri(meth)acrylate and tetramethylolmethane tetra(meth)acrylate; (meth)acrylate compounds having a pentaerythritol-derived skeleton such as pentaerythritol tri(meth)acrylate and pentaerythritol tetra(meth)acrylate; (meth)acrylate compounds having a dipentaerythritol-derived skeleton such as dipentaerythritol penta(meth)acrylate and dipentaerythritol hexa(meth)acrylate; (meth)acrylate compounds having a ditrimethylolpropane-derived skeleton such as ditrimethylolpropane tetra(meth)acrylate; and (meth)acrylate compounds having a diglycerin-derived skeleton. Among these, (meth)acrylate compounds having a skeleton derived from trimethylolpropane are preferred from the viewpoint of via resolution and adhesion strength to copper plating, and trimethylolpropanetri(meth)acrylate is more preferred. Here, the "(meth)acrylate compound having a skeleton derived from XXX" (where XXX is the name of the compound) means an esterified product of XXX and (meth)acrylic acid, and this esterified product also includes compounds modified with alkylene oxy groups.

[0085] If the photosensitive resin composition contains a crosslinking agent (C), the amount of the crosslinking agent (C) is not particularly limited, but from the viewpoint of heat resistance and dielectric constant, it is preferably 1 to 85 parts by mass, more preferably 5 to 70 parts by mass, even more preferably 10 to 50 parts by mass, and particularly preferably 10 to 40 parts by mass, per 100 parts by mass of component (A).

[0086] <(D) Elastomer> The photosensitive resin composition may further contain an elastomer as component (D). The inclusion of elastomer (D) in the photosensitive resin composition tends to further improve the adhesion strength to copper plating. In addition, the inclusion of elastomer (D) in the photosensitive resin composition tends to suppress the "decrease in flexibility and adhesion strength to copper plating" caused by strain (internal stress) that may occur due to the curing shrinkage of component (A). Elastomer (D) may be used alone or in combination of two or more types.

[0087] (D) The elastomer may have reactive functional groups at the molecular ends or in the molecular chain. Examples of reactive functional groups include acid anhydride groups, epoxy groups, hydroxyl groups, carboxyl groups, amino groups, amide groups, isocyanate groups, acrylic groups, methacrylic groups, vinyl groups, etc. Among these, from the viewpoint of via resolution and adhesion strength to copper plating, acid anhydride groups, epoxy groups, hydroxyl groups, carboxyl groups, amino groups, and amide groups are preferred, acid anhydride groups and epoxy groups are more preferred, and acid anhydride groups are even more preferred. As for the acid anhydride group, it is preferable that it is an acid anhydride group derived from phthalic anhydride, maleic anhydride, trimellitic anhydride, pyromellitic anhydride, hexahydrophthalic anhydride, tetrahydrophthalic anhydride, methylnadic anhydride, nadic anhydride, glutaric anhydride, dimethylglutaric anhydride, diethylglutaric anhydride, succinic anhydride, methylhexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, etc., and it is more preferable that it is an acid anhydride group derived from maleic anhydride. (D) When the elastomer has acid anhydride groups, from the viewpoint of via resolution and dielectric constant, the number of acid anhydride groups in one molecule is preferably 1 to 10, more preferably 3 to 10, and even more preferably 6 to 10.

[0088] The photosensitive resin composition preferably contains an elastomer having an ethylenically unsaturated group and an acidic substituent as (D) elastomer. Examples of the ethylenically unsaturated group and acidic substituent include the same ones as those found in component (A). Among these, it is preferable that the (D) elastomer has the aforementioned acid anhydride group as the acidic substituent and the 1,2-vinyl group described later as the ethylenically unsaturated group.

[0089] (D) Examples of elastomers include polybutadiene elastomers, polyester elastomers, styrene elastomers, olefin elastomers, urethane elastomers, polyamide elastomers, acrylic elastomers, silicone elastomers, and derivatives of these elastomers. Among these, polybutadiene elastomers are preferred from the viewpoint of improving adhesion strength with copper plating, as well as improving compatibility and solubility with resin components.

[0090] Polybutadiene elastomers are preferably those that contain a 1,2-vinyl group and have both a 1,4-trans structural unit and a 1,4-cis structural unit. As mentioned above, from the viewpoint of via resolution, the polybutadiene elastomer is preferably a polybutadiene elastomer that has been modified with an acid anhydride and has an acid anhydride group, and more preferably a polybutadiene elastomer that has an acid anhydride group derived from maleic anhydride. Polybutadiene elastomers are available commercially, and specific examples include "POLYVEST MA75", "POLYVEST EP MA120" (both manufactured by Evonik), "Ricon 100", "Ricon 130MA8", "Ricon 131MA5", "Ricon 131MA17", and "Ricon 184MA6" (all manufactured by Clay Valley).

[0091] The polybutadiene elastomer may be polybutadiene having epoxy groups [hereinafter sometimes referred to as epoxidized polybutadiene] from the viewpoint of adhesive strength with copper plating. From the viewpoint of adhesive strength with copper plating and flexibility, the epoxidized polybutadiene is preferably epoxidized polybutadiene represented by the following general formula (D-1).

[0092] (In the formula, a, b, and c represent the ratios of the structural units in parentheses, respectively: a is between 0.05 and 0.40, b is between 0.02 and 0.30, and c is between 0.30 and 0.80. Furthermore, a + b + c = 1.00 and (a + c) > b. y represents the number of structural units in square brackets and is an integer between 10 and 250.)

[0093] In the general formula (D-1) above, the order in which the structural units within the square brackets are combined is not limited to any particular order. In other words, the structural units shown on the left, the structural units shown in the center, and the structural units shown on the right may be swapped, and if we represent them as (a), (b), and (c), then there are various possible combinations, such as -[(a)-(b)-(c)]-[(a)-(b)-(c)-]-, -[(a)-(c)-(b)]-[(a)-(c)-(b)-]-, -[(b)-(a)-(c)]-[(b)-(a)-(c)-]-, -[(a)-(b)-(a)]-[(c)-(b)-(a)-]-, -[(a)-(b)-(a)]-[(c)-(b)-(c)-]-, and -[(c)-(b)-(c)]-[(b)-(a)-(a)-]-. From the viewpoint of adhesion strength with copper plating and flexibility, a is preferably 0.10 to 0.30, b is preferably 0.10 to 0.30, and c is preferably 0.40 to 0.80. Also, from a similar viewpoint, y is preferably an integer between 30 and 180.

[0094] Examples of polyester elastomers include those obtained by polycondensation of a dicarboxylic acid or its derivative with a diol compound or its derivative. Examples of dicarboxylic acids include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, and naphthalenedicarboxylic acid, and aromatic dicarboxylic acids in which the hydrogen atoms of the aromatic kernel are substituted with methyl groups, ethyl groups, phenyl groups, etc.; aliphatic dicarboxylic acids having 2 to 20 carbon atoms such as adipic acid, sebacic acid, and dodecanedicarboxylic acid; and alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid. Examples of diol compounds include aliphatic diols such as ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, and 1,10-decanediol; alicyclic diols such as 1,4-cyclohexanediol; and aromatic diols such as bisphenol A, bis(4-hydroxyphenyl)methane, bis(4-hydroxy-3-methylphenyl)propane, and resorcinol. Furthermore, as a polyester elastomer, a multiblock copolymer is preferred in which the aromatic polyester (e.g., polybutylene terephthalate) portion is the hard segment component and the aliphatic polyester (e.g., polytetramethylene glycol) portion is the soft segment component. Multiblock copolymers come in various grades depending on the type, ratio, and molecular weight of the hard and soft segments.

[0095] (D) The number-average molecular weight of the elastomer is not particularly limited, but is preferably 10,000 to 80,000, may be 20,000 to 70,000, may be 30,000 to 65,000, or may be 40,000 to 60,000. The number-average molecular weight of (D) the elastomer is determined by gel permeation chromatography (GPC) using tetrahydrofuran as the solvent, on a standard polystyrene basis.

[0096] If the photosensitive resin composition contains (D) elastomer, the content of (D) elastomer is not particularly limited, but from the viewpoint of heat resistance and adhesive strength with copper plating, it is preferably 0.5 to 15% by mass, more preferably 1 to 10% by mass, even more preferably 1 to 8% by mass, and particularly preferably 3 to 8% by mass, based on the total amount of resin components of the photosensitive resin composition.

[0097] <(F) Organic Filler> The photosensitive resin composition may further contain an organic filler as component (F). The inclusion of the (F) organic filler in the photosensitive resin composition tends to result in a lower specific gravity for the photosensitive resin composition and the photosensitive resin film, and depending on the material, the dielectric constant tends to be further reduced. Component (F) may include resin particles formed from at least one selected from the group consisting of resins having fluorine atoms, polyethylene, polypropylene, polystyrene, polyphenylene ether, and silicone. The volume average particle diameter of the resin particles is not particularly limited, but is preferably 20 to 1,000 nm, more preferably 30 to 800 nm, even more preferably 50 to 500 nm, and particularly preferably 100 to 300 nm.

[0098] If the photosensitive resin composition contains (F) organic filler, the content of (F) organic filler is preferably 20% by mass or less, more preferably 10% by mass or less, and even more preferably 5% by mass or less, based on the total amount of resin components of the photosensitive resin composition. The photosensitive resin composition does not have to contain component (F). The content of (F) organic filler may be 0.1 to 20% by mass or 1 to 20% by mass, based on the total amount of resin components of the photosensitive resin composition.

[0099] <(G) Curing Agent> The photosensitive resin composition may further contain a curing agent as component (G). The photosensitive resin composition tends to have improved heat resistance, dielectric constant, etc., by containing a curing agent (G). A single type of curing agent (G) may be used alone, or two or more types may be used in combination.

[0100] (G) As a curing agent, the curing agent for the thermosetting resin (B) described above may be used. For example, if the thermosetting resin (B) is an epoxy resin, it is preferable to use an epoxy resin curing agent. Examples of such epoxy resin curing agents include guanamines such as acetoganamine and benzoguanamine; polyamines such as diaminodiphenylmethane, m-phenylenediamine, m-xylenediamine, diaminodiphenylsulfone, dicyandiamide, urea, urea derivatives, melamine, and polybasic hydrazides; organic salts and / or epoxy adducts thereof; amine complexes of boron trifluoride; triazine derivatives such as ethyldiamino-S-triazine, 2,4-diamino-S-triazine, and 2,4-diamino-6-xylyl-S-triazine; and polyphenols such as polyvinylphenol, polyvinylphenol brominated, phenol novolac, alkylphenol novolac, and triazine ring-containing phenol novolac resin. The polyphenol may be a modified polyphenol, for example, modified with melamine, benzoguanamine, etc. The hydroxyl group equivalent of the polyphenol is not particularly limited, but is preferably 40 to 300 g / eq, may be 40 to 250 g / eq, 60 to 200 g / eq, 80 to 160 g / eq, or 100 to 140 g / eq. Here, the hydroxyl group equivalent (g / eq) can be determined by titration using the acetylation method with acetic anhydride.

[0101] If the photosensitive resin composition contains (G) a curing agent, the content of (G) a curing agent is not particularly limited, but from the viewpoint of further improving heat resistance and dielectric constant, it is preferably 0.01 to 10% by mass, more preferably 0.05 to 5% by mass, and even more preferably 0.1 to 1% by mass, based on the total amount of resin components of the photosensitive resin composition.

[0102] <(H) Curing Accelerator> The photosensitive resin composition may further contain a curing accelerator as component (H). The photosensitive resin composition tends to have improved heat resistance, dielectric constant, etc., by containing a curing accelerator (H). A single type of curing accelerator (H) may be used alone, or two or more types may be used in combination.

[0103] (H) Examples of curing accelerators include imidazole compounds such as 2-methylimidazole, 2-ethyl-4-methylimidazole, 1-benzyl-2-methylimidazole, and isocyanate-masquimidazole (an addition reaction product of hexamethylene diisocyanate resin and 2-ethyl-4-methylimidazole); tertiary amines such as trimethylamine and N,N-dimethyloctylamine; organophosphines such as tributylphosphine and triphenylphosphine; phosphonium salts such as tri-n-butyl(2,5-dihydroxyphenyl)phosphonium bromide and hexadecyltributylphosnium chloride; quaternary ammonium salts such as benzyltrimethylammonium chloride and phenyltributylammonium chloride; the aforementioned polybasic acid anhydrides; diphenyliodonium tetrafluoroborate, triphenylsulfonium hexafluoroantimonate, and 2,4,6-triphenylthiopyrillium hexafluorophosphate. Among these, imidazole compounds are preferred from the viewpoint of obtaining excellent curing properties.

[0104] When the photosensitive resin composition contains a (H) curing accelerator, the content of the (H) curing accelerator is not particularly limited, but from the viewpoint of further improving heat resistance and dielectric constant, it is preferably 0.01 to 10% by mass, more preferably 0.05 to 5% by mass, and even more preferably 0.1 to 2% by mass, based on the total amount of resin components of the photosensitive resin composition.

[0105] <(I) Photopolymerization Initiator> The photosensitive resin composition may further contain a photopolymerization initiator as component (I). The photosensitive resin composition tends to have improved via resolution by containing a photopolymerization initiator (I). A single type of photopolymerization initiator (I) may be used, or two or more types may be used in combination. From the viewpoint of via resolution, the photosensitive resin composition preferably contains two or more types of component (I), and more preferably contains two types of component (I).

[0106] (I) The photopolymerization initiator is not particularly limited as long as it can photopolymerize ethylenically unsaturated groups, and can be appropriately selected from commonly used photopolymerization initiators. (I) Examples of photopolymerization initiators include benzoin compounds; acetophenone compounds; anthraquinone compounds; ketal compounds; acridine compounds; acylphosphine oxide compounds; oxime ester compounds; thioxanthone compounds, etc.

[0107] (I) As the photopolymerization initiator, acetophenone compounds and thioxanthone compounds are preferred, and it is more preferable to use acetophenone compounds and thioxanthone compounds in combination. In addition, (I) the photopolymerization initiator may be an oxime ester compound or an acylphosphine oxide compound. Oxime ester compounds have the advantage of improving photocurability, and acylphosphine oxide compounds have the advantage of improving the degree of curing at the bottom of the cured product obtained by curing the photosensitive resin film and suppressing undercuts. Furthermore, using oxime ester compounds and acylphosphine oxide compounds in combination tends to further improve the resolution of the vias.

[0108] When the photosensitive resin composition contains (I) a photopolymerization initiator, the content of (I) the photopolymerization initiator is not particularly limited, but is preferably 0.01 to 20% by mass, more preferably 0.05 to 10% by mass, even more preferably 0.05 to 3% by mass, and particularly preferably 0.05 to 1.0% by mass, based on the total amount of resin components of the photosensitive resin composition. When the content of (I) the photopolymerization initiator is above the lower limit, there is a tendency to reduce the elution of the exposed area during development, and when it is below the upper limit, there is a tendency to improve heat resistance.

[0109] <(J) Photosensitizer> The photosensitive resin composition may optionally contain a photosensitizer as component (J). One type of (J) photosensitizer may be used alone, or two or more types may be used in combination. From the viewpoint of via resolution, the photosensitive resin composition may contain two or more types of (J). Examples of (J) photosensitizers include tertiary amines; alkyl dialkylaminobenzoate esters; bis(dialkylamino)benzophenone; phosphine compounds; toluidine compounds; anthracene compounds; perylene compounds; coumarin compounds, etc. From the viewpoint of via resolution and via shape improvement, bis(dialkylamino)benzophenone is preferred as the (J) photosensitizer, and 4,4'-bis(diethylamino)benzophenone is more preferred.

[0110] When the photosensitive resin composition contains (J) a photosensitizer, the content of (J) the photosensitizer is not particularly limited, but is preferably 0.01 to 5% by mass, more preferably 0.05 to 3% by mass, even more preferably 0.1 to 1.5% by mass, and particularly preferably 0.1 to 1.0% by mass, based on the total amount of resin components in the photosensitive resin composition. When the content of (J) the photosensitizer is above the lower limit, the degree of curing at the bottom of the cured product obtained by curing the photosensitive resin film tends to be sufficiently high, and when it is below the upper limit, the degree of curing at the bottom of the cured product tends to be moderately low.

[0111] <(K) Additives> The photosensitive resin composition may optionally contain various known and conventional additives such as pigments like phthalocyanine blue, phthalocyanine green, iodine green, diazo yellow, crystal violet, titanium dioxide, carbon black, and naphthalene black; adhesive aids such as melamine; foam stabilizers such as silicone compounds; polymerization inhibitors; thickeners; and flame retardants. The content of these (K) additives may be adjusted as appropriate according to their respective purposes, but for each, the content is preferably 0.01 to 5% by mass, but may also be 0.05 to 3% by mass, or 0.1 to 1% by mass, based on the total amount of resin components in the photosensitive resin composition.

[0112] <Diluent> The photosensitive resin composition may contain a diluent as needed. Organic solvents can be used as diluents. Examples of organic solvents include ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene, xylene, and tetramethylbenzene; glycol ether compounds such as methyl cellosolve, butyl cellosolve, methyl carbitol, butyl carbitol, propylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol diethyl ether, and triethylene glycol monoethyl ether; esters such as ethyl acetate, butyl acetate, 2-methoxy-1-methyl ethyl acetate, propylene glycol monoethyl ether acetate, butyl cellosolve acetate, and carbitol acetate; aliphatic hydrocarbons such as octane and decane; and petroleum solvents such as petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha, and solvent naphtha. One diluent may be used alone, or two or more may be used in combination.

[0113] If the photosensitive resin composition contains a diluent, the amount of diluent can be appropriately selected to adjust the concentration of the total solid content in the photosensitive resin composition to a range of preferably 40 to 90% by mass, more preferably 50 to 85% by mass, and even more preferably 60 to 80% by mass. By adjusting the amount of diluent used to this range, the coatability of the photosensitive resin composition is improved, and it becomes possible to form finer patterns.

[0114] Photosensitive resin compositions can be obtained by kneading and mixing each component using a roll mill, bead mill, or the like.

[0115] [Method for Manufacturing Semiconductor Packages] This disclosure also provides a method for manufacturing semiconductor packages, which includes mounting semiconductor elements on a printed circuit board obtained by the method for manufacturing printed circuit boards of this embodiment. More specifically, a semiconductor package can be manufactured by mounting semiconductor elements such as semiconductor chips and memory at predetermined positions on a printed circuit board obtained by the method for manufacturing this embodiment, and then sealing the semiconductor elements with a sealing resin or the like.

[0116] The embodiments will be described in more detail below with reference to examples, but this disclosure is not limited to these examples.

[0117] <Synthesis Example 1> Synthesis of a photopolymerizable compound (A1) having an ethylenically unsaturated group and an acidic substituent 350 parts by mass of dicyclopentadiene type epoxy resin (XD-1000, manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent 252 g / eq, softening point 74.2°C, component (a1), number of ring-forming carbon atoms in the alicyclic skeleton: 10), 70 parts by mass of acrylic acid (component (a2)), 0.5 parts by mass of methylhydroquinone, and 120 parts by mass of carbitol acetate were charged and reacted by heating to 90°C and stirring until the mixture was dissolved. Next, the obtained solution was cooled to 60°C, 2 parts by mass of triphenylphosphine was added, and the mixture was heated to 100°C and reacted until the acid value of the solution was 1 mg KOH / g. To the reacted solution, 98 parts by mass of tetrahydrophthalic anhydride (component (a3)) and 85 parts by mass of carbitol acetate were added, and the mixture was heated to 80°C and reacted for 6 hours. Subsequently, the mixture was cooled to room temperature to obtain a photopolymerizable compound (A1) having ethylenically unsaturated groups and acidic substituents with a solid content of 73% by mass [acid value: 60 mg KOH / g, weight-average molecular weight: 2,000].

[0118] Preparation Example 1 (Preparation of Photosensitive Resin Composition) The composition was prepared according to the formulation shown in Table 1 (the units of the numerical values ​​in the table are parts by mass, and in the case of a solution, the amount is on a solid content basis), and then kneaded in a three-roll mill. Subsequently, 2-methoxy-1-methylethyl acetate and methyl ethyl ketone were added to obtain a photosensitive resin composition in order to achieve a solid content concentration of 65% by mass.

[0119]

[0120] The components used in Table 1 are as follows: [(A) Photopolymerizable compounds having ethylenically unsaturated groups and acidic substituents] ・A1; Photopolymerizable compound (A1) having ethylenically unsaturated groups and acidic substituents obtained in Synthesis Example 1, compound containing an alicyclic skeleton

[0121] [(B) Thermosetting resin] ・B1; "YX-4000" (manufactured by Mitsubishi Chemical Corporation, biphenyl aralkyl type epoxy resin, epoxy equivalent: 180-192 g / eq)

[0122] [(C) Crosslinking agent] ・C1; "DPHA" (Dipentaerythritol hexaacrylate)

[0123] [(D) Elastomer] ・D1; "Ricon 131MA17" (manufactured by Clay Valley, maleic acid-modified polybutadiene, number average molecular weight 54,000 (catalog value))

[0124] [(E) Inorganic filler] E1; Spherical fused silica (volume average particle size 0.5 μm)

[0125] [(I) Photopolymerization initiators] • I1; Photopolymerization initiator 1: 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, acetophenone compounds • I2; Photopolymerization initiator 2: 2,4-diethylthioxanthone, thioxanthone compounds

[0126] In the following examples and comparative examples, the peel force between the protective film and the photosensitive resin film, and the peel force between the carrier film and the photosensitive resin film were measured by the following methods.

[0127] [1. Method for measuring the peel force between the protective film and the photosensitive resin film] A photosensitive resin film, with a carrier film on the bottom and a protective film on top, was cut into strips measuring 2 cm x 30 cm. Double-sided tape was attached to the carrier film side of the cut photosensitive resin film strips and adhered to the device stage. Using the adhesive / film peel analysis device "VPA-H100F" (manufactured by Kyowa Interface Science Co., Ltd.), the peel force between the protective film and the photosensitive resin film was measured with a stage movement speed of 300 mm / min, a peel angle of 60°, and an initial peel force of 0 (zero) N. The measurement was performed with a measurement distance of 70 mm and 250 measurements, and the average of the obtained measurements was taken as the peel force between the protective film and the photosensitive resin film.

[0128] [2. Method for measuring the peel force between the carrier film and the photosensitive resin film] A photosensitive resin film, with a carrier film on the bottom and a protective film on top, was cut into strips measuring 2 cm x 30 cm. Double-sided tape was attached to the protective film side of the cut photosensitive resin film strips and adhered to the apparatus stage. Using the adhesive / film peel analysis device "VPA-H100F" (manufactured by Kyowa Interface Science Co., Ltd.), the peel force between the carrier film and the photosensitive resin film was measured with a stage movement speed of 300 mm / min, a peel angle of 60°, and an initial peel force of 0 (zero) N. The measurement was performed with a measurement distance of 70 mm and 250 measurements, and the average of the obtained measurements was taken as the peel force between the carrier film and the photosensitive resin film.

[0129] Example 1 (Manufacturing of Printed Wiring Boards) (Photosensitive Resin Film Formation Process (1)) A polyethylene terephthalate film "Purex A5300" (manufactured by Toyobo Co., Ltd., treated with a mold release agent) with a thickness of 25 μm was prepared as a carrier film. The photosensitive resin composition obtained in Preparation Example 1 was applied to the carrier film while adjusting the thickness so that the film thickness after drying would be 20 μm, and a photosensitive resin film was formed by drying it at 100°C for 10 minutes using a hot air convection dryer. (Protective Film Installation Process (2)) Subsequently, a polyethylene terephthalate film "Toyobo Ester Film G2" (manufactured by Toyobo Co., Ltd., untreated with a mold release agent) with a thickness of 25 μm was laminated as a protective film onto the surface of the formed photosensitive resin film opposite to the surface in contact with the carrier film. In this way, a photosensitive resin film was prepared by laminating the carrier film and the protective film. Here, using a photosensitive resin film obtained by the same method, the peel force between the protective film and the photosensitive resin film, and the peel force between the carrier film and the photosensitive resin film were measured according to the method described above. The peel force (average measurement) between the protective film, a 25 μm thick polyethylene terephthalate film "Toyobo Ester Film G2" (manufactured by Toyobo Co., Ltd., untreated with release agent), and the photosensitive resin film was approximately 0.15 N / cm. On the other hand, the peel force (average measurement) between the carrier film, a 25 μm thick polyethylene terephthalate film "Purex A5300" (manufactured by Toyobo Co., Ltd., treated with release agent), and the photosensitive resin film was approximately 0.01 N / cm.

[0130] (Carrier film peeling process (3) and lamination process (4)) While peeling the carrier film from the "photosensitive resin film formed by laminating a carrier film and a protective film" manufactured by the above method, the laminate was applied to the circuit board using a press-type vacuum laminator "MVLP-500" (manufactured by Meiki Seisakusho Co., Ltd.) with a pressing pressure of 0.4 MPa, a press hot plate temperature of 75°C, a vacuum evacuation time of 25 seconds, a lamination press time of 25 seconds, and an atmospheric pressure of 4 kPa or less to obtain a laminate. The obtained laminate was subjected to 200 mJ / cm² exposure using a parallel light exposure machine (manufactured by Oak Seisakusho Co., Ltd., "EXM-1201") with an ultra-high pressure mercury lamp as the light source. ２ The entire surface was exposed. Next, a UV exposure apparatus was used to apply 2,000 mJ / cm². ２ After exposure with the specified exposure dose, the material was heated at 170°C for 1 hour. Figure 1 shows an SEM image of a cross-section of the laminate obtained by the same method. From Figure 1, it can be observed that the density of the inorganic filler is low in the region corresponding to a depth of 5 μm from the top surface of the interlayer insulating layer formed from the photosensitive resin film, and high in the region corresponding to a depth of 5 μm or 10 μm from the bottom surface of the interlayer insulating layer. Therefore, it is considered that the adhesive strength between the interlayer insulating layer formed from the photosensitive resin film and the copper plating formed thereon is higher compared to the conventional method (see Comparative Example 1).

[0131] (Photovia Formation Process (5)) For the laminate, a step tablet and via evaluation mask are used on the carrier film using an i-line stepper (UX-7, manufactured by Ushio Inc.) to apply 210 mJ / cm². ２ The film was exposed to light at a wavelength of 365 nm. After peeling off the carrier film, the film was developed using a spray developer at 30°C with a 1% by mass sodium carbonate aqueous solution for 40 seconds to form vias approximately 60 μm in size.

[0132] (Roughening treatment process (6)) Next, as a swelling solution, 2 L of "Swelling Dip Securigant MV" (manufactured by Atotec Japan Co., Ltd.) with added sodium hydroxide [sodium hydroxide concentration: 3 g / L] was heated to 70°C, and the laminate was immersed for 5 minutes. After that, it was rinsed with water at 25°C for 1 minute, followed by running water rinsing at 25°C for 3 minutes. Next, as a roughening solution, 2 L of "Dosing Securigant PMV" (manufactured by Atotec Japan Co., Ltd.) with added sodium hydroxide [sodium hydroxide concentration: 40 g / L] was heated to 60°C, and the laminate was immersed for 5 minutes. After that, it was rinsed with pure water at 50°C for 1 minute. (Neutralization process (7)) Next, a sulfuric acid aqueous solution was added to "Reduction Solution Securigant MV" (manufactured by Atotech Japan Co., Ltd.) (total volume: 2,000 ml) to a sulfuric acid concentration of 48 ml / L. This solution was then heated to 50°C and immersed for 5 minutes at 50°C. After that, it was rinsed with water at 25°C for 1 minute, followed by a rinse with running water at 25°C for 3 minutes.

[0133] (Circuit pattern formation process (8)) Next, the laminate was treated with the 60°C alkaline cleaner "Cleaner Securigant 902" (manufactured by Atotec Japan Co., Ltd.) for 5 minutes, and then degreased and washed. After washing, the laminate was treated with the 23°C pre-dip solution "Pre-dip Neogant B" (manufactured by Atotec Japan Co., Ltd.) for 1 minute. After that, the laminate was treated with the 35°C activator solution "Activator Neogant 834" (manufactured by Atotec Japan Co., Ltd.) for 5 minutes, and then treated with the 30°C reducing solution "Reducer Neogant WA" (manufactured by Atotec Japan Co., Ltd.) for 5 minutes. The laminate thus obtained was placed in a chemical copper solution ("Basic Print Gant MV-TP1", "Copper Print Gant MV-TP1", "Moderator Print Gant MV-TP1", "Stabilizer Print Gant MV-TP1", "Reducer Cu" (all manufactured by Atotec Japan Co., Ltd.) and sodium hydroxide), and electroless plating was performed until the plating thickness was approximately 0.5 μm. After the electroless plating, an annealing treatment was performed at 120°C for 30 minutes to remove residual hydrogen gas. Subsequently, copper sulfate electroplating was performed, followed by an annealing treatment at 180°C for 60 minutes to form a conductive layer with a thickness of 25 μm. Then, a printed circuit board was manufactured by forming a circuit pattern on the laminate using a semi-additive process.

[0134] Comparative Example 1 (Conventional Method) The same procedure was followed as in Example 1, except that a 25 μm thick polyethylene terephthalate film "Toyobo Ester Film G2" (manufactured by Toyobo Co., Ltd., untreated with mold release agent) was used as the carrier film and a 25 μm thick polyethylene terephthalate film "Purex A5300" (manufactured by Toyobo Co., Ltd., treated with mold release agent) was used as the protective film. The peel force between the protective film and the photosensitive resin film, and the peel force between the carrier film and the photosensitive resin film were measured according to the method described above. As a result, the peel force (average value measured) between the protective film, a 25 μm thick polyethylene terephthalate film "Purex A5300" (manufactured by Toyobo Co., Ltd., treated with mold release agent), and the photosensitive resin film was approximately 0.01 N / cm. On the other hand, the peel force (average measurement) between the carrier film, a 25 μm thick polyethylene terephthalate film "Toyobo Ester Film G2" (manufactured by Toyobo Co., Ltd., untreated with release agent), and the photosensitive resin film was approximately 0.15 N / cm. In other words, the relationship between the peel force between the protective film and the photosensitive resin film and the peel force between the carrier film and the photosensitive resin film in Example 1 was reversed. Figure 2 shows a cross-sectional SEM image of the laminate at the stage after the bonding process (4) is completed. From Figure 2, it can be observed that the density of the inorganic filler is low in the region corresponding to a depth of 1 to 5 μm from the bottom surface of the interlayer insulating layer formed from the photosensitive resin film, particularly in the region corresponding to a depth of 3 to 5 μm from the bottom surface, and that the density of the inorganic filler is generally high in the region corresponding to a depth of 15 μm from the top surface of the interlayer insulating layer formed from the photosensitive resin film. Therefore, compared to the laminate of Example 1, the adhesive strength between the interlayer insulating layer formed from the photosensitive resin film and the copper plating formed thereon is considered to be lower (for example, 0.05 kN / m or more lower, and sometimes 0.08 kN / m or more lower).

Claims

1. A method for manufacturing a printed circuit board, comprising the following steps: (1) Applying a photosensitive resin composition containing an inorganic filler to a carrier film to form a photosensitive resin film on the carrier film. (2) Placing a protective film on the upper surface of the formed photosensitive resin film. (3) Peeling off the carrier film while the protective film remains attached to the photosensitive resin film. (4) Attaching the exposed photosensitive resin film surface from step (3) to a circuit board.

2. The method for manufacturing a printed circuit board according to claim 1, wherein the peeling force between the carrier film and the photosensitive resin film is smaller than the peeling force between the protective film and the photosensitive resin film.

3. The method for manufacturing a printed circuit board according to claim 1, wherein the carrier film is treated with a release agent on the side to which the photosensitive resin composition is applied.

4. The method for manufacturing a printed circuit board according to claim 1, wherein in the photosensitive resin film formed in (1) above, the proportion of inorganic filler in the protective film side in the range of 1 to 10 μm thickness is smaller than the proportion of inorganic filler in the carrier film side in the range of 1 to 10 μm thickness.

5. The method for manufacturing a printed circuit board according to claim 1, wherein the carrier film is a resin film or a metal foil.

6. The method for manufacturing a printed circuit board according to claim 1, wherein the protective film is a resin film.

7. The method for producing a printed circuit board according to claim 1, wherein the photosensitive resin composition further contains (A) a photopolymerizable compound having an ethylenically unsaturated group and an acidic substituent, and (B) a thermosetting resin.

8. The method for manufacturing a printed circuit board according to claim 7, wherein the photosensitive resin composition further contains (C) a crosslinking agent.

9. The method for manufacturing a printed circuit board according to claim 7, wherein the photosensitive resin composition further contains (I) a photopolymerization initiator.

10. A method for manufacturing a semiconductor package, comprising mounting a semiconductor element on a printed circuit board obtained by the manufacturing method described in any one of claims 1 to 9.

11. A laminated film comprising a carrier film, a photosensitive resin film containing an inorganic filler, and a protective film stacked in that order from bottom to top, wherein the peel force between the carrier film and the photosensitive resin film is less than the peel force between the protective film and the photosensitive resin film.

12. The laminated film according to claim 11, wherein the photosensitive resin film has a lower inorganic filler content in the protective film side than the inorganic filler content in the protective film side than the inorganic filler content in the protective film side.

13. The laminated film according to claim 11, wherein the thickness of the photosensitive resin film is 1 to 100 μm.

Images