Method for manufacturing a frp precursor

Abstract

The present application provides a manufacturing method of FRP precursor, which has: a pre-coating process of coating a resin varnish with a content of filler material of 5% or less by volume in solid components on a sheet-shaped aggregate, and a melt-bonding process of melt-bonding a pair of resin films each with a content of filler material of 30% or more by volume on both surfaces of the aggregate after the pre-coating process.

Description

Technical Field

[0001] This disclosure relates to a method for manufacturing an FRP precursor. Background Technology

[0002] FRP (Fiber Reinforced Plastics) is a composite material that uses materials with high elastic modulus, such as fibers, as aggregates and incorporates these aggregates into a base material (matrix) such as plastic to increase strength. FRP is a composite material that exhibits excellent weather resistance, heat resistance, chemical resistance, is inexpensive, lightweight, and durable.

[0003] By leveraging these properties, FRP is used in a wide range of fields. For example, due to its malleability and high strength, FRP is used as a structural material in residential equipment, ships, vehicles, and aircraft. Additionally, its insulating properties allow FRP to be used in electrical installations and electronic components such as semiconductor chips.

[0004] Integration density in electronic components such as semiconductor chips is becoming increasingly high, and the miniaturization of the printed circuit boards (PCBs) on which they are mounted is also progressing. Although semiconductor chips themselves generate relatively little heat, their dense mounting results in a very high heat density per unit area (see, for example, Non-Patent Document 1). Cooling methods using cooling fans or heat sinks are employed to dissipate the generated heat; however, mounting these components leads to device enlargement. Wearable electronic devices, in particular, require small and thin designs, making cooling methods using fans or heat sinks difficult. Therefore, the applicant has previously proposed a method to diffuse the generated heat across the printed circuit board to the entire device by increasing the thermal conductivity of the printed circuit board (see Patent Document 1).

[0005] To improve the thermal conductivity of printed circuit boards, methods often employ high-density filling of FRP precursors such as prepregs with fillers whose thermal conductivity is higher than that of the resin. However, high-density filling with fillers can impregnate the resin composition into aggregates such as glass fiber cloth, potentially leading to decreased insulation and heat resistance. Furthermore, during resin composition coating onto aggregates, fillers may settle within the impregnation container, resulting in situations where the resin composition containing the desired amount of filler cannot be coated onto the aggregates.

[0006] Therefore, a method is sometimes used whereby the resin varnish is applied to a carrier film and dried to form a resin film, which is then laminated onto the aggregate under heating and pressure (see, for example, Patent Document 2). With this method, it is less likely for filler material to settle during lamination, and a resin film containing the desired amount of filler material can be laminated onto the aggregate.

[0007] Prior art documents

[0008] Patent documents

[0009] Patent document 1: Japanese Patent Laid-Open No. 2008-031405

[0010] Patent document 2: Japanese Patent Laid-Open No. 2007-176169

[0011] Non-patent documents

[0012] Non-patent document 1: Scientific Systems Research Society (in Japanese: サイエンティフィック·システム研究会), Proceedings of the Scientific and Technical Computing Subcommittee, 2006 (October 5, 2006), by Hisashige Ando (in Japanese: 安藤壽茂), Trends in Semiconductor Technology and Computer Technology (in Japanese: 半導体技術とコンピュータ技術の動向) Summary of the invention

[0013] Problems to be solved by the invention

[0014] In the method using a resin film described in Patent Document 2 and the like, in order to handle a material having lower fluidity compared to the method of coating a resin varnish, when laminating the resin film on, for example, a glass cloth, it is necessary to pay attention to allowing the resin to sufficiently infiltrate between the filaments of the yarns constituting the glass cloth. However, during lamination, the yarns exhibit the effect of a filter cloth, and there is a case where only the resin infiltrates between the filaments of the yarns and a filler material aggregates on the surface portion of the yarns like filter residues. In the case where such a result is formed, the filler material ratio of the resin layer near the surface of the glass cloth locally becomes high, resulting in high viscosity and poor fluidity, and it has been found that the formability during lamination deteriorates.

[0015] Therefore, an object of the present disclosure is to provide a method for manufacturing an FRP precursor that uses a resin film and suppresses a local increase in the filler material ratio while allowing the resin to infiltrate into the voids of the aggregate.

[0016] Means for solving the problems

[0017] The inventors of the present invention conducted in-depth research and found that the object can be achieved by using the method for manufacturing an FRP precursor of the present disclosure.

[0018] The present disclosure includes the following embodiments [1] to [8].

[0019] [1] A method for manufacturing an FRP precursor, comprising:

[0020] A step of pre-coating a sheet-like aggregate with a resin varnish having a filler material content of 5% by volume or less in the solid component, and

[0021] The step of pre-coating the aggregate as described above and then fusion bonding a pair of resin films, each containing 30% or more of filler material, to the two surfaces of the aggregate.

[0022] [2] According to the method for manufacturing the FRP precursor described in [1] above, in the pre-coating step above, the amount of resin varnish used satisfies the following formula (1).

[0023] [Mathematical Expression 1]

[0024]

[0025] [3] The method for manufacturing the FRP precursor as described in [1] or [2] above, wherein the melt bonding includes the following step of film lamination:

[0026] The steps for membrane lamination are as follows: Under normal pressure, one surface of the resin membrane of the pair of resin membranes, which serves as the aggregate side surface, is lamination onto one of the two surfaces of the aggregate, and the other surface of the resin membrane of the pair of resin membranes, which serves as the aggregate side surface, is lamination onto the other surface of the aggregate to obtain the FRP precursor.

[0027] [4] The method for manufacturing the FRP precursor described in [3] above further includes a step of preheating the aggregate side surface of the two surfaces of the resin film before performing the above film pressing step.

[0028] [5] The method for manufacturing the FRP precursor described in [3] or [4] above further includes a step of preheating the two surfaces of the aggregate before performing the above-mentioned film pressing step.

[0029] [6] The manufacturing method of the FRP precursor described in any of [1] to [5] above, wherein the packing thickness of the aggregate is 30 μm or more.

[0030] [7] The method for manufacturing the FRP precursor according to any one of [1] to [6] above, wherein the average particle diameter of the filler material contained in the resin varnish is 0.1 to 10 μm.

[0031] [8] The method for manufacturing the FRP precursor according to any one of [1] to [7] above, wherein the resin film is a thermosetting resin film.

[0032] Invention Effects

[0033] According to the FRP precursor manufacturing method of this embodiment, although a resin film is used, the localized increase in the filler ratio can be suppressed, while the resin can penetrate into the finer parts of the aggregate. Therefore, there is no localized increase in the filler ratio of the resin layer near the surface of the glass cloth, and high viscosity and poor flowability are avoided, thereby suppressing the deterioration of formability during lamination. Thus, it is possible to improve thermal conductivity while ensuring formability using filler materials. Attached Figure Description

[0034] Figure 1 This is a conceptual diagram of an apparatus that can be used in the pre-coating operation of the FRP precursor manufacturing method of this embodiment.

[0035] Figure 2 This is a conceptual diagram of an apparatus that can be used after pre-coating in the manufacturing method of the FRP precursor of this embodiment.

[0036] Figure 3 This is a schematic diagram illustrating the cross-section of glass cloth used to explain the thickness of the stack. Detailed Implementation

[0037] This embodiment is a method for manufacturing an FRP precursor, which includes:

[0038] The pre-coating step (hereinafter sometimes referred to as the "pre-coating process") of resin varnish with a filler content of less than 5% by volume in the solid components of the flake aggregate coating, and...

[0039] After the above pre-coating step, a step of fusion bonding a pair of resin films, each containing 30% or more of filler material, to the two surfaces of the aggregate (hereinafter referred to as the "fusion bonding process" for convenience) is performed.

[0040] Here, in this specification, as with the pre-coating process and melt-bonding process described above, for convenience, a given operation is sometimes referred to as "XX process". However, the XX process is not limited to the specific method described in this specification.

[0041] The following is based on... Figure 1 and Figure 2 Meanwhile, one embodiment of the manufacturing method of the FRP precursor of this embodiment will be described, however, this embodiment is not limited to this embodiment.

[0042] Specifically, the pre-coating apparatus 100 and the FRP precursor manufacturing apparatus 200 (hereinafter sometimes simply referred to as the FRP precursor manufacturing apparatus 200) used after the pre-coating process will be described. It should be noted that the FRP precursor manufacturing apparatus 200 will be described as an apparatus that uses a pair of resin films 54 to adhere to both sides of the sheet-shaped pre-coated aggregate 41.

[0043] The pre-coating apparatus 100 and the FRP precursor manufacturing apparatus 200 are placed under atmospheric pressure. Since this embodiment is carried out under atmospheric pressure, unlike the case of vacuum lamination, it is easier to handle even if manufacturing failures occur. The FRP precursor manufacturing method of this embodiment can be implemented using the pre-coating apparatus 100 and the FRP precursor manufacturing apparatus 200.

[0044] Figure 1 and Figure 2 In the first method, a "two-stage method" is used, where, in the pre-coating apparatus 100, the pre-coated aggregate 41 is temporarily wound using the pre-coated aggregate winding apparatus 8, and the wound aggregate 41 is then used in the FRP precursor manufacturing apparatus 200 after the pre-coating process. However, a "one-stage method" can also be used, where, in... Figure 1 The pre-coating apparatus 100 shown does not wind the pre-coated aggregate 41 using the pre-coated aggregate winding device 8, but instead directly... Figure 2 This is used in the FRP precursor manufacturing apparatus 200, which is used after the pre-coating process shown. However, Figure 1 The pre-coating device 100 shown can increase the coating speed, enabling the aggregate feed rate to be higher than [the specified value]. Figure 2 The FRP precursor manufacturing apparatus 200 is shown. Therefore, it is preferable that the pre-coating apparatus 100 and the FRP precursor manufacturing apparatus 200 are independent apparatuses, i.e., the above-described two-stage method is preferred. In the above-described two-stage method, by using multiple FRP precursor manufacturing apparatuses 200, productivity is significantly increased.

[0045] (Pre-coating process, pre-coating device 100;) Figure 1 )

[0046] As previously stated, the pre-coating process involves coating the sheet aggregate 40 with a resin varnish containing less than 5% by volume of filler material in the solid components. Here, the term "solid components" in this specification refers to components in the composition other than water, organic solvents (described later), and other volatile substances. That is, solid components also include substances that are liquid, syrupy, or waxy at room temperature (around 25°C), and do not necessarily refer to solids.

[0047] This pre-coating process can be performed using a pre-coating apparatus 100. The pre-coating apparatus 100 includes a resin varnish 13a, a container 13b, and guide rollers 14, 15, and 16. In the pre-coating apparatus 100, the aggregate 40 fed from the aggregate feeding device 2 is immersed in the resin varnish 13a, and the resin varnish 13a is coated onto the aggregate 40. The pre-coating apparatus 100 then feeds the aggregate 41 coated with the resin varnish 13a (i.e., the pre-coated aggregate) 41 to the dryer 17.

[0048] Resin varnish 13a is a resin varnish in which the content of filler material is less than 5% by volume of the solid components. Details will be described later.

[0049] There are no particular limitations on the container 13b, as long as it can hold the resin varnish 13a and has a width greater than that of the aggregate 40. A given amount of resin varnish 13a is added into the container 13b.

[0050] The guide rollers 14, 15, and 16 are all rollers that redirect the forward direction of the aggregate 40. For guide rollers 14 and 16, in order to redirect the aggregate 40 above them, they are located near the front and inside sides respectively on the upper side of container 13b in the direction in which the aggregate 40 is fed. For guide roller 15, in order to redirect the aggregate 40 below it, the lower side of guide roller 15 is located below the surface of the resin varnish 13a inside container 13b. Figure 1 In the middle, the steering roller 15 is submerged in the resin varnish 13a.

[0051] In the FRP precursor manufacturing method of this embodiment, resin varnish 13a is pre-coated onto the aggregate 40, and resin is pre-introduced into the voids of the aggregate. Here, the voids of the aggregate, for example, if the aggregate is glass cloth, are the portions between the filaments of the yarn constituting the glass cloth. Therefore, when the thermosetting resin sheet is laminated onto the aggregate in the melt bonding process described later, it is possible to prevent the resin from the thermosetting resin sheet from seeping into the filaments of the yarn, and to avoid the agglomeration of filler material on the surface of the yarn like filter residue. As a result, there is no localized increase in the filler material ratio in the resin layer near the surface of the glass cloth, and high viscosity and poor flowability are avoided, thus suppressing the deterioration of formability during lamination. Thus, it is possible to improve thermal conductivity while ensuring formability using filler material. Furthermore, the pre-coating device 100 tends to improve the adhesion between the resin film and the aggregate. Hereinafter, these effects will sometimes be referred to as "Effect A".

[0052] It should be noted that effect A tends to become more pronounced, particularly when the aggregate build-up thickness is 30 μm or more. The greater the aggregate build-up thickness, the more the resin from the thermosetting resin sheet penetrates into the aggregate, and the easier it is for the filler material in the thermosetting resin sheet to aggregate onto the yarn surface. Therefore, when the aggregate build-up thickness is 30 μm or more, the aforementioned effect A resulting from pre-impregnating the resin varnish into the aggregate becomes significant. From this perspective, the aggregate build-up thickness is preferably 30 μm or more, more preferably 30–250 μm, further preferably 35–200 μm, and particularly preferably 40–180 μm. Alternatively, the aggregate build-up thickness may be 30–70 μm, 100–250 μm, or 140–250 μm.

[0053] It should be noted that the so-called "stacking thickness" refers to... Figure 3 The thickness of the area shown is specifically the thickness measured in accordance with JIS R3420 (2013) 7.10.1 (wherein Method B is used in “7.10.1.4 Operation”).

[0054] Here, in the pre-coating process, the amount of resin varnish used preferably satisfies the following formula (1).

[0055] [Mathematical Expression 2]

[0056]

[0057] Hereinafter, the term “volume of solid components of the coated resin varnish / (bulk volume of aggregate - true volume of aggregate)” in formula (1) is sometimes referred to as “solid component penetration rate”. The lower limit of the solid component penetration rate is preferably 0.10, more preferably 0.15, and the upper limit is preferably 0.5, more preferably 0.45. These values ​​can be rewritten independently as the lower limit or upper limit of formula (1) above.

[0058] Regarding the amount of resin varnish used, by ensuring the solid component penetration rate is 0.05 or higher, there is a tendency to fully realize the aforementioned effects brought about by pre-coating the aggregate 40 with resin varnish 13a. Furthermore, by ensuring the solid component penetration rate is 0.6 or lower, the filler material in the resin film can be sufficiently impregnated into the gaps between the fiberglass yarns. Therefore, it is easier to manufacture high-density FRP precursors filled with filler material, and it is possible to avoid excessive resin impregnation in the resin varnish. As a result, there is a tendency to easily maintain the properties of the resin film.

[0059] After pre-coating the aggregate 40 with resin varnish 13a, it is heated and dried using a dryer 17 to remove organic solvents from the resin varnish and adjust the hardness of the resin coated on the aggregate. There are no particular limitations on the dryer, but a hot air dryer is preferred. There are no particular limitations on the drying temperature, but it is preferably adjusted within the range of 120–200°C, but can also be 150–190°C or 160–185°C.

[0060] The pre-coated aggregate 41, whose resin hardness has been adjusted using the dryer 17, moves toward the winding device 8 for pre-coated aggregate.

[0061] (FRP precursor manufacturing apparatus 200 that can be used after the pre-coating process:) Figure 2 )

[0062] The FRP precursor manufacturing apparatus 200 includes a pre-coated aggregate feeding device 2', a pair of resin film feeding devices 3, 3, a sheet heating and pressurizing device 6, and an FRP precursor winding device 9. The FRP precursor manufacturing apparatus 200 preferably also includes a sheet pressurizing and cooling device 7, a pair of protective film peeling mechanisms 4, 4, and a pair of protective film winding devices 5, 5.

[0063] The finished pre-coated aggregate feeding device 2' is a device that feeds out the finished pre-coated aggregate 41 obtained in the above-mentioned pre-coating process. It is a device that rotates the roller on which the finished pre-coated aggregate 41 is wound in the opposite direction to the winding direction and feeds out the finished pre-coated aggregate 41 wound on the roller. Figure 2 In the process, the pre-coated aggregate feeding device 2' feeds the pre-coated aggregate 41 from the underside of the roller to the FRP precursor winding device 9.

[0064] Each resin film delivery device 3 has a roller wound with a resin film 50 with a protective film, and a support mechanism that can rotatably support the roller while applying a given tension to the resin film 50 with the protective film being delivered.

[0065] Each resin film dispensing device 3 is a device that rotates a roller wound with a resin film 50 having a protective film in the opposite direction to the winding direction, thereby dispensing the resin film 50 with a protective film wound on the roller. As will be described later, the resin film 50 with a protective film is a sheet-like film comprising a resin film 54, a protective film 52 laminated on one aggregate-side film surface of the resin film 54 (the surface on the aggregate 40 side of the two surfaces of the resin film 54), and a carrier film (not shown) laminated on the side of the resin film 54 opposite to the protective film 52.

[0066] A pair of resin film delivery devices 3 and 3 are located on the surface 41a side and the back side 41b side of the pre-coated aggregate 41 being delivered.

[0067] A resin film feeding device 3 is located on the surface 41a side of the pre-coated aggregate 41 being fed out, and feeds a resin film 50 with a protective film from the underside of a roller to a protective film peeling mechanism 4 in such a way that a protective film 52 is located on the side of the pre-coated aggregate 41 being fed out.

[0068] Similarly, another resin film feeding device 3 is located on the back side 41b of the pre-coated aggregate 41 being fed out, and feeds another resin film 50 with a protective film from the top of the roller to another protective film peeling mechanism 4 in such a way that the protective film 52 is located on the side of the aggregate 41 being fed out.

[0069] A pair of protective film peeling mechanisms 4 and 4 are each a steering roller located on the surface 41a side and the back 41b side of the pre-coated aggregate 41 being fed out.

[0070] A protective film peeling mechanism 4 is a mechanism in which a resin film 50 with a protective film, which is fed from a resin film feeding device 3 and moves toward a protective film peeling mechanism 4, is received by the surface of a rotating guide roller. One resin film 54 of the resin film 50 with a protective film moves toward the sheet heating and pressing device 6, while a protective film 52 moves toward a protective film winding device 5, thereby peeling off a protective film 52 from the resin film 50 with a protective film. As a result, the aggregate side film surface 54a of the resin film 54 is exposed.

[0071] Similarly, the other protective film peeling mechanism 4 is a mechanism in which another resin film 50 with a protective film, which is fed out from another resin film feeding device 3 and moves toward the other protective film peeling mechanism 4, is received by the surface of a rotating guide roller, so that another resin film 54 of the other resin film 50 with a protective film moves toward the sheet heating and pressing device 6, while another protective film 52 moves toward the other protective film winding device 5, thereby peeling off another protective film 52 from the other resin film 50 with a protective film. As a result, the aggregate side film surface 54a of the other resin film 54 is exposed.

[0072] Prior to the membrane pressing process described later, it is preferable to preheat the aggregate-side membrane surface 54a of the two surfaces of the resin membrane 54 using preheating mechanisms 11a and 11b (hereinafter referred to as "membrane preheating process A"). As a result, the melting of the thermosetting resin of each resin membrane 54 is promoted, and it tends to be easily melt-bonded.

[0073] From the same point of view, prior to the film pressing process described later, it is preferable to further preheat the two surfaces (surface 41a side and back side 41b side) of the pre-coated aggregate 41 using preheating mechanisms 10a and 10b (hereinafter referred to as "aggregate preheating process B").

[0074] This embodiment preferably includes at least one of the above-described membrane preheating step A and the above-described aggregate preheating step B, more preferably both, but may also omit one or both of them.

[0075] The heating temperatures in the above-mentioned membrane preheating step A and aggregate preheating step B are preferably 5 to 70°C higher than the heating temperature in the membrane pressing step described later, more preferably 7 to 60°C higher, and even more preferably 10 to 50°C higher. These heating temperatures refer to the heating temperatures in preheating mechanisms 10a, 10b, 11a, and 11b, respectively, and refer to the surface temperature of the resin membrane and the surface temperature of the aggregate.

[0076] It should be noted that in the membrane preheating step A, it is more preferable to set the heating temperature so that the surface temperature of the resin membrane is within the range of -20°C to +30°C of the lowest melt viscosity temperature of the resin membrane; more preferably, it is set within the range of -10°C to +25°C of the lowest melt viscosity temperature of the resin membrane; particularly preferably, it is set within the range of -5°C to +15°C of the lowest melt viscosity temperature of the resin membrane; and most preferably, it is set within the range of +2°C to +15°C of the lowest melt viscosity temperature of the resin membrane. Here, in this specification, the lowest melt viscosity temperature is the temperature measured using a rheometer, and more specifically, the temperature measured according to the method described in the examples.

[0077] Furthermore, in the aggregate preheating step B, it is more preferable to set the heating temperature so that the surface temperature of the resin impregnated in the aggregate is within the range of -20°C to +30°C of the resin's lowest melt viscosity temperature. More preferably, the heating temperature is set within the range of -5°C to +30°C of the resin's lowest melt viscosity temperature. Particularly preferable, the heating temperature is set within the range of +5°C to +25°C of the resin's lowest melt viscosity temperature. Most preferably, the heating temperature is set within the range of +8°C to +17°C of the resin's lowest melt viscosity temperature. If the heating temperature in the film preheating step A and the aggregate preheating step B is too low, the degree of softening of the resin film and the resin in the aggregate will be small, and there is a tendency for the mixing of the resin film and the aggregate to decrease. If the preheating temperature is too high, the thermosetting process will proceed excessively, and the resin in the resin film and the aggregate will solidify, still tending towards a decrease in the mixing of the resin film and the aggregate.

[0078] There are no particular limitations on the heating methods in the membrane preheating step A and the aggregate preheating step B; various methods such as radiation, contact, and convection can be used. Among these, radiation is preferred. As a radiative heating element, infrared light or visible light containing infrared light can be used. By using such a heating element, deformation of the resin surface and stickiness of the membrane surface caused by membrane "shaking" can be suppressed. In the above-mentioned membrane preheating step A and aggregate preheating step B, from the viewpoint of suppressing natural cooling, the heating position is preferably within 20 seconds of the production line speed near the heating pressure roller, and more preferably within 5 seconds of the production line speed.

[0079] A pair of protective film winding devices 5 and 5 are respectively located on the surface 41a side and the back side 41b side of the pre-coated aggregate 41 that is being delivered, and are used to wind the protective films 52 and 52 that are peeled off by a pair of protective film peeling mechanisms 4 and 4.

[0080] (Melt-bonding process:) Figure 2 )

[0081] As mentioned above, the melt-bonding process is a process of melting and bonding a pair of resin films, each containing 30% or more of filler material, onto the two surfaces of the aggregate after the pre-coating process.

[0082] This fusion bonding process can be implemented using a sheet heating and pressing device 6. The sheet heating and pressing device 6 has a pair of heated compression rollers and a compression force applying mechanism (not shown) that applies compression force to the pair of heated compression rollers. In order to heat at a given, pre-set temperature, the pair of heated compression rollers have heating elements inside.

[0083] The sheet heating and pressing device 6 uses a pair of rotating heating and compression rollers to press the resin films 54, 54 onto the pre-coated aggregate 41 to form a sheet-like FRP precursor 60 (film pressing process), while simultaneously sending the FRP precursor 60 toward the sheet pressing and cooling device 7.

[0084] Specifically, the above-mentioned membrane pressing process is a process in which, under normal pressure, one surface of the resin film of the pair of resin films that serves as the aggregate side surface is pressed onto one surface of the two aggregate surfaces, and the other surface of the other resin film of the pair of resin films that serves as the aggregate side surface is pressed onto the other surface of the two aggregate surfaces to obtain the FRP precursor.

[0085] Specifically, with a pair of resin films 54 and 54 delivered from protective film peeling mechanisms 4 and 4 respectively stacked on the surface 41a and back 41b of the pre-coated aggregate 41 delivered from the pre-coated aggregate delivery device 2', the pre-coated aggregate 41 and the pair of resin films 54 and 54 delivered from protective film peeling mechanisms 4 and 4 respectively enter between a pair of heated compression rollers.

[0086] When the resin film 54 is heated and pressurized to bond to the pre-coated aggregate 41, the temperature of the heating compression roller is preferably in the range of -40°C to +20°C of the lowest melt viscosity temperature of the resin film 54, more preferably in the range of -30°C to +10°C, even more preferably in the range of -20°C to +5°C, and most preferably in the range of -20°C to -5°C. The pressure can be any linear pressure, but preferably a linear pressure of 50–1200 μm at the penetration depth of the 6.4 mm perforation during roller lamination using the test method of IPC-TM-650 No. 2.3.17.1B, more preferably a linear pressure of 100–1000 μm.

[0087] At this time, with the aggregate-side film surface 54a of one resin film 54 in contact with the surface 41a of the pre-coated aggregate 41, one resin film 54 is laminated onto the pre-coated aggregate 41. Additionally, with the aggregate-side film surface 54a of another resin film 54 in contact with the back surface 41b of the pre-coated aggregate 41, another resin film 54 is laminated onto the pre-coated aggregate 41. The FRP precursor 60 is thus formed. The FRP precursor 60 delivered from the sheet heating and pressurizing device 6 is at a high temperature.

[0088] The sheet pressurization and cooling device 7 has a pair of cooling compression rollers and a compression force applying mechanism (not shown) that applies compression force to the pair of cooling compression rollers. The pair of cooling compression rollers cool the high-temperature FRP precursor 60 delivered from the sheet heating and pressurization device 6 by the rotating pair of cooling compression rollers and deliver it to the FRP precursor winding device 9.

[0089] The FRP precursor winding device 9 has a roller for winding a sheet-shaped FRP precursor 60 fed from the sheet pressure cooling device 7, and a drive mechanism (not shown) for rotating the roller.

[0090] The aggregate, the resin varnish, and the resin film used in the manufacturing method of the FRP precursor are described in detail below.

[0091] (aggregate)

[0092] Examples of aggregates include woven and nonwoven fabrics made by using two or more inorganic fiber substrates such as glass and carbon, either alone or in combination; organic fiber substrates such as aramid and cellulose; and metal fiber substrates containing alloys of metals such as iron, copper, and aluminum. As an aggregate, it is sufficient to select one appropriately based on purposes such as insulation and conductivity. Glass cloth (glass woven fabric) is a suitable aggregate option.

[0093] Aggregate per 1m 2 The aggregate porosity is 15cm. 3 In the above situations, effect A tends to become more significant. This is because if there are many pores, the resin in the resin membrane can easily penetrate into the pores, while the filler material has difficulty penetrating the pores. When there are few pores, the amount of resin in the resin membrane penetrating into the pores is small. Therefore, the filler material on the surface of the aggregate (or the surface of the yarn if it is glass cloth) is less likely to aggregate like filter residue.

[0094] Based on the above viewpoints, every 1m 2 The void space in the aggregate can be 15–100 cm. 3 It can also be 20-85cm 3 It can also be 23-75cm 3 It should be noted that the voids are determined by subtracting the true volume from the packed volume.

[0095] Furthermore, when the aggregate is a woven fabric such as glass cloth, if the number of filaments constituting the yarn is 50 or more, the fabric tends to function more effectively as a filter cloth for the resin membrane. Therefore, with this type of aggregate, the aforementioned effect A is more easily and significantly manifested. The number of filaments constituting the yarn can be 50 to 500, 50 to 450, 100 to 450, or 100 to 300. Alternatively, the number of filaments constituting the yarn can be 300 to 500.

[0096] (Resin varnish)

[0097] As mentioned above, the resin varnish used in the pre-coating process is a resin varnish in which the content of filler material is 5% by volume or less of the solid components, and the remainder consists of volatile components such as organic solvents. The content of filler material in this resin varnish is preferably 3% by volume or less of the solid components, more preferably 2.5% by volume or less, and even more preferably 2.0% by volume or less. This small amount of filler material in the resin varnish is used to prevent the resin varnish from becoming too fluid; for example, if a resin with higher viscosity is used, it may not contain any filler material. That is, in the resin varnish used in the pre-coating process, the lower limit value for the content of filler material can be 0% by volume of the solid components, 0.2% by volume of the solid components, 0.5% by volume of the solid components, 1.0% by volume of the solid components, or 1.3% by volume of the solid components.

[0098] The average particle diameter of the filler material contained in the resin varnish is preferably 0.1 to 10 μm, more preferably 0.3 to 7 μm, and even more preferably 0.5 to 5 μm. If the average particle diameter of the filler material contained in the resin varnish is within the above range, the resin varnish will easily have a moderate flowability.

[0099] There are no particular restrictions on the filler materials that can be contained in resin varnishes. Examples include oxides such as silica, alumina, zirconium dioxide, mullite, and magnesium oxide; hydroxides such as aluminum hydroxide, magnesium hydroxide, and hydrotalcite; nitride ceramics such as aluminum nitride, silicon nitride, and boron nitride; insoluble salts such as barium titanate and calcium titanate; natural or synthetic clay minerals such as talc, montmorillonite, soapstone, and hydrotalcite; and metal particles and carbon particles. From the viewpoint of adjusting insulation and flowability, inorganic filler materials are preferred as filler materials in resin varnishes, and oxides and hydroxides are more preferred. From the viewpoints of price, insulation, low thermal expansion, flame retardancy, and mechanical wear resistance, silica and aluminum hydroxide are further preferred.

[0100] From the viewpoint of allowing the resin varnish to penetrate into the voids of the aggregate (for example, between the filaments of the yarn in the case of glass cloth), the concentration of the solid components is preferably 5 to 55% by mass, but may also be 5 to 50% by mass, 5 to 45% by mass, 15 to 45% by mass, 25 to 45% by mass, or 35 to 45% by mass.

[0101] There are no particular restrictions on the organic solvents contained in resin varnishes. Examples include ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, and 4-methyl-2-pentanone; aromatic solvents such as toluene, xylene, and mesitylene; ester solvents such as ethyl acetate and γ-butyrolactone; ether solvents such as tetrahydrofuran; alcohol solvents such as ethylene glycol monoethyl ether, dipropylene glycol monomethyl ether, and tripropylene glycol monomethyl ether; nitrogen-containing solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, and N-methylpyrrolidone; and sulfur-containing solvents such as dimethyl sulfoxide. These organic solvents can be used alone or in combination of two or more.

[0102] It should be noted that the other components contained in the resin varnish are described in the same way as the components contained in the resin film described later.

[0103] (Resin film)

[0104] There are no particular limitations on the type of resin film, however, a thermosetting resin film is preferred. The description of the resin film in this specification can be read as an explanation of a thermosetting resin film.

[0105] The resin film used in the melt bonding of aggregates is obtained by drying a resin composition (preferably a thermosetting resin composition) containing 30% by volume or more of filler material, especially in the case of a thermosetting resin composition, by drying the film after it has been formed into a film. Here, "sterilization" refers to the formation of a state defined in JIS K 6900 (1994), also known as semi-curing. There are no particular restrictions on the drying conditions; however, drying at 80–180°C for 1–5 minutes is acceptable.

[0106] The aforementioned thermosetting resin film is a film containing thermosetting resin, filler material, and other components as needed. The components that the aforementioned thermosetting resin film can contain are described in detail below.

[0107] There are no particular limitations on the thermosetting resins mentioned above; examples include phenolic resins, urea-formaldehyde resins, furan resins, epoxy resins, and polyimide resins. In particular, from the viewpoints of workability, operability, and price, epoxy resins are preferred.

[0108] As the epoxy resin, epoxy resins with two or more functionalities are preferred. There are no particular limitations on the type of epoxy resin, and examples include bisphenol-type epoxy resins such as bisphenol A type epoxy resin, bisphenol F type epoxy resin, and bisphenol AD ​​type epoxy resin; alicyclic epoxy resins; linear phenolic epoxy resins such as phenol linear phenolic epoxy resin, cresol linear phenolic epoxy resin, bisphenol A linear phenolic epoxy resin, and aralkyl linear phenolic epoxy resin; diglycidyl ethers of polyfunctional phenols; and their hydrogenated derivatives. These epoxy resins can be used alone or in combination of two or more. While there are no particular limitations, the epoxy resin preferably includes at least one selected from bisphenol-type epoxy resins and linear phenolic epoxy resins, and more preferably includes a linear phenolic epoxy resin.

[0109] When flame retardancy is required in FRP precursors, halogenated epoxy resins can be used. Alternatively, to achieve flame retardancy without adding halogenated epoxy resins, compounds commonly referred to as flame retardants or flame retardant additives, such as tetrabromobisphenol A, decabromodiphenyl ether, antimony oxide, tetraphenylphosphine, organophosphorus compounds, and zinc oxide, can be added.

[0110] When using epoxy resin as a thermosetting resin, an epoxy resin curing agent can be used.

[0111] There are no particular limitations on epoxy resin curing agents; examples include phenolic resins, amine compounds, acid anhydrides, boron trifluoride monoethylamine, isocyanates, dicyandiamide, urea resins, etc.

[0112] There are no particular limitations on the type of phenolic resin. Examples include methyl phenolic resins; linear phenolic resins such as phenol and cresol; naphthalene-type phenolic resins; high-ortho-type linear phenolic resins; terpene-modified phenolic resins; terpene-phenol-modified phenolic resins; aralkyl-type phenolic resins; dicyclopentadiene-type phenolic resins; salicylaldehyde-type phenolic resins; and benzaldehyde-type phenolic resins. Among these, phenolic linear phenolic resins, cresol linear phenolic resins, and locally modified aminotriazine linear phenolic resins are preferred.

[0113] As amine compounds, there are no particular limitations. Examples include aliphatic amines such as triethylenetetramine, tetraethylenepentamine, and diethylaminopropylamine; and aromatic amines such as m-phenylenediamine and 4,4'-diaminodiphenylmethane.

[0114] There are no particular limitations on the types of acid anhydrides used; examples include phthalic anhydride, methyltetrahydrophthalic anhydride, tetrahydrophthalic anhydride, and hexahydrophthalic anhydride. These epoxy resin curing agents can be used alone or in combination of two or more.

[0115] The preferred content of the epoxy resin curing agent is an amount with a reactive group equivalent ratio of 0.3 to 1.5 equivalents relative to 1 epoxy equivalent of the epoxy resin. If the content of the epoxy resin curing agent is within the above range, the degree of curing is easier to control, and productivity tends to improve.

[0116] Thermosetting resin films can also contain curing accelerators.

[0117] There are no particular limitations on the curing accelerator, and examples include imidazole compounds, organophosphorus compounds, tertiary amines, and quaternary ammonium salts. The imidazole compound can be a latent imidazole compound whose secondary amino group is blocked by acrylonitrile, isocyanate, melamine, acrylate, etc. Examples of imidazole compounds used herein include imidazole, 2-methylimidazolium, 4-ethyl-2-methylimidazolium, 2-phenylimidazolium, 2-undecylimidazolium, 1-benzyl-2-methylimidazolium, 2-heptadecanylimidazolium, 4,5-diphenylimidazolium, 2-methylimidazoline, 2-ethyl-4-methylimidazoline, 2-undecylimidazoline, and 2-phenyl-4-methylimidazoline. While there are no particular limitations, the curing accelerator preferably contains an imidazole compound.

[0118] In addition, thermosetting resin films can be films containing photoinitiators. These photoinitiators are substances that initiate curing by generating free radicals, anions, or cations through photodecomposition.

[0119] These curing accelerators can be used alone or in combination of two or more.

[0120] The content of the curing accelerator is preferably 0.01 to 20 parts by weight relative to 100 parts by weight of the thermosetting resin. If the content of the curing accelerator is 0.01 parts by weight or more relative to 100 parts by weight of the thermosetting resin, there is a tendency to obtain a sufficient curing promotion effect. If it is 20 parts by weight or less, there is a tendency to have excellent preservation properties of the thermosetting resin film and excellent physical properties of the cured product. In addition, there is also a tendency to have excellent economic benefits.

[0121] From the perspectives of opacity, abrasion resistance, low thermal expansion, dielectric properties, thermal conductivity, reduced magnetic permeability, and increased content of components, thermosetting resin films are films containing a given amount of filler material.

[0122] There are no particular limitations on filler materials; however, examples include oxides such as silica, alumina, zirconium dioxide, mullite, and magnesium oxide; hydroxides such as aluminum hydroxide, magnesium hydroxide, and hydrotalcite; nitride ceramics such as aluminum nitride, silicon nitride, and boron nitride; insoluble salts such as barium titanate and calcium titanate; natural or synthetic clay minerals such as talc, montmorillonite, soapstone, and hydrotalcite; metal particles and carbon particles; and magnetic materials such as ferrite. From an insulation perspective, inorganic fillers are preferred as fillers in thermosetting resin films; and from the perspectives of price and low thermal expansion, silica is more preferred.

[0123] Filler materials can be used alone or in combination of two or more.

[0124] Since filler materials have a wider specific gravity range compared to resins, ranging from low to high specific gravity materials, the amount of filler material added is preferably considered as volume fraction rather than parts by mass.

[0125] Regarding the filler content, from the viewpoint of high-density filling of fillers with high thermal conductivity, it is 30% by volume or more in the thermosetting resin film, preferably 30-65% by volume, more preferably 30-55% by volume, and even more preferably 35-45% by volume. By ensuring the filler content in the thermosetting resin film is 30% by volume or more, it can be considered a state of high-density filler filling, thus sufficiently improving the thermal conductivity and low thermal expansion of the FRP precursor. Furthermore, if the filler content in the thermosetting resin film is 65% by volume or less, a significant increase in resin viscosity can be suppressed, preventing a tendency for workability and adhesion to deteriorate during molten bonding to aggregates.

[0126] In addition to the above-mentioned components, other components may be included as needed, within the scope that does not impair the effect of this embodiment.

[0127] For example, a material containing a coupling agent may be used to improve the dispersibility of filler materials and their adhesion to aggregates or objects. There are no particular limitations on the coupling agent; examples include vinyl trichlorosilane, vinyltriethoxysilane, and other vinyl-containing silane coupling agents; epoxy-containing silane coupling agents such as 3-epoxypropoxypropyltrimethoxysilane and 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane; amino-containing silane coupling agents such as 3-aminopropyltrimethoxysilane and N-2-(aminoethyl)-3-aminopropyltriethoxysilane; and titanate-based coupling agents. These coupling agents can be used alone or in combination of two or more.

[0128] The coupling agent content in the thermosetting resin film is preferably 0.01 to 5% by mass. If the coupling agent content in the thermosetting resin film is 0.01% by mass or more, it tends to adequately cover the surface of the aggregate and the surface of the filler material. If it is 5% by mass or less, it tends to suppress the generation of excess coupling agent.

[0129] A thermosetting resin composition containing the above-mentioned components is coated onto a carrier film, unwanted organic solvents are removed, and the film is heated and dried to obtain a thermosetting resin film.

[0130] There are no particular limitations on the carrier film. Examples include organic films such as polyethylene terephthalate (PET), biaxially oriented polypropylene (OPP), polyethylene, polyvinyl fluorite, and polyimide; films made of copper, aluminum, or alloys of these metals; and films whose surfaces have been treated with a release agent.

[0131] As an FRP precursor obtained using the manufacturing method of this embodiment, prepreg blanks are preferably examples. When using a thermosetting resin film as the resin film, FRP is manufactured by fully thermosetting the obtained FRP precursor, that is, fully acetylated. Here, acetylation refers to producing a state defined as acetylation in JIS K6900 (1994).

[0132] The FRP obtained in this way, due to its high-density filler material, not only has high thermal conductivity but also excellent heat resistance, and can effectively suppress blurring (an indicator of the formability of FRP precursors). Furthermore, when the filler material is inorganic, it also exhibits excellent low thermal expansion.

[0133] Alternatively, one FRP precursor obtained in this embodiment can be prepared, or 2 to 20 sheets can be stacked together, with metal foil disposed on one or both sides. This configuration is then used for lamination forming, thereby manufacturing a metal-clad laminate. For example, the metal foil used in laminates for electrical insulating materials can be used. The metal-clad laminate is configured such that metal foil is present on one or both sides of the aforementioned laminate.

[0134] The metal used as the foil is preferably copper, gold, silver, nickel, platinum, molybdenum, ruthenium, aluminum, tungsten, iron, titanium, chromium, or an alloy containing at least one of these metal elements, with copper being more preferred.

[0135] Laminated forming conditions can be achieved using multi-stage pressing, multi-stage vacuum pressing, continuous forming, autoclave forming machines, etc., at temperatures of 100–250°C, pressures of 0.2–10 MPa, and heating times of 0.1–5 hours.

[0136] Example

[0137] The present invention will be further described in detail below using the following embodiments; however, these embodiments do not limit the present disclosure.

[0138] [Example 1]

[0139] <Preparation of Resin Varnish 1 for Pre-coating Process>

[0140] 100 parts by weight of phenolic linear phenolic epoxy resin (N-660; manufactured by DIC Corporation) and 60 parts by weight of cresol linear phenolic resin (KA-1165; manufactured by DIC Corporation) were mixed with 30 parts by weight of cyclohexane and 200 parts by weight of methyl ethyl ketone, and stirred thoroughly to dissolve them. Then, 5 parts by weight of amorphous silica (AEROSIL200; manufactured by AEROSIL Corporation) as a filler, 1 part by weight of coupling agent (A-187; manufactured by Momentive Performance Materials Co., Ltd.), and 1.4 parts by weight of isocyanate-terminated imidazole (G8009L; manufactured by Daiichi Kogyo Pharmaceutical Co., Ltd.) as a curing accelerator were added and stirred to dissolve and disperse them, thus preparing a resin varnish with a solid content of 42% by weight.

[0141] <Preparation of Thermosetting Resin Film A>

[0142] To 100 parts by weight of phenolic linear phenolic epoxy resin (N-660; manufactured by DIC Corporation) and 60 parts by weight of cresol linear phenolic resin (KA-1165; manufactured by DIC Corporation), 15 parts by weight of cyclohexane and 130 parts by weight of methyl ethyl ketone were added, and the mixture was stirred thoroughly to dissolve the resin. Then, 180 parts by weight of aluminum hydroxide (CL-303; manufactured by Sumitomo Chemical Co., Ltd.) as a filler, 1 part by weight of coupling agent (A-187; manufactured by Momentive Performance Materials Co., Ltd.), and 2.5 parts by weight of isocyanate-terminated imidazole (G8009L; manufactured by Daiichi Kogyo Pharmaceutical Co., Ltd.) as a curing accelerator were added and stirred to dissolve and disperse the resin, yielding a thermosetting resin varnish A with a solid content of 70% by weight.

[0143] The thermosetting resin varnish A was coated onto a 580mm wide PET film (G-2; manufactured by Teijin Dupont Film Co., Ltd.), resulting in a coating width of 525mm and a dried thickness of 50μm. The film was then dried at 130°C to produce the thermosetting resin film A.

[0144] It should be noted that the minimum melt viscosity temperature of the thermosetting resin film A produced was measured using a rheometer (AR-200ex; manufactured by TA Instrument JAPAN Co., Ltd., φ20mm fixture) at a heating rate of 3℃ / min, and the result was 124℃.

[0145] (Pre-coating process)

[0146] Then, the above-mentioned resin varnish 1 was diluted with a mixed solvent of methyl ethyl ketone and cyclohexanone (methyl ethyl ketone: cyclohexanone = 10:1 (mass ratio)) and coated onto the glass cloth (basic weight 209 g / m²) used as aggregate. 2 After processing (IPC#7628, substrate width 530mm: manufactured by Nan Ya Plastics Co., Ltd.), the substrate is dried at 175°C using a hot air dryer to remove the solvent, yielding a base-coated glass cloth α with a solid content of 8% by mass. It should be noted that the mass of the solid content in the base-coated glass cloth α can be calculated based on the difference between the mass of the base-coated glass cloth α and the mass of the glass cloth used as aggregate.

[0147] In addition, the minimum melt viscosity temperature of the resin impregnated into the prepared base-coated glass cloth α was determined using a rheometer (AR-200ex; manufactured by TA Instrument JAPAN Co., Ltd., φ20mm fixture) at a heating rate of 3℃ / min, and the result was 133℃.

[0148] (Membrane lamination process)

[0149] A thermosetting resin film A is used to clamp a base-coated glass cloth α. A pressure-heated roller is used at a roller temperature of 110°C, a linear pressure of 0.2 MPa, and a speed of 1.0 m / min to pressure-impregnate the thermosetting resin film A into the aggregate. Specifically, at a distance of approximately 30 mm from the pressure-heated roller (based on the center of the heated surface), a halogen heater is used to preheat the side of the thermosetting resin film A that contacts the aggregate, raising the surface temperature to 130°C. The aggregate is also preheated to a surface temperature of 145°C before the aforementioned pressure impregnation is performed.

[0150] Subsequently, the material is cooled using cooling rollers and then wound to produce FRP precursor A, which is known as a prepreg blank.

[0151] [Example 2]

[0152] Except for changing the following points in Example 1, the same operation is performed to produce FRP precursor B as a so-called prepreg blank.

[0153] (Change Point)

[0154] Instead of producing a thermosetting resin film A with a dry thickness of 50 μm, a thermosetting resin film (referred to as "thermosetting resin film B") is produced with a dry thickness of 40 μm. Minimum melt viscosity: 131 °C. This thermosetting resin film B is used instead of thermosetting resin film A.

[0155] • Use glass cloth (basic weight 209g / m²) 2 The IPC#7628 substrate width (530mm, manufactured by Nan Ya Plastics Co., Ltd.) has been changed to glass cloth (basic weight 48g / m²). 2 IPC#1080, substrate width 530mm: manufactured by Nitto Boshoku Co., Ltd.

[0156] Instead of obtaining a base-coated glass cloth α with a solid content of 8% by mass, a base-coated glass cloth (referred to as "base-coated glass cloth β") is prepared by adjusting the solid content to 25% by mass. The minimum melt viscosity of the resin in base-coated glass cloth β is 138°C. This base-coated glass cloth β is used in place of base-coated glass cloth α.

[0157] • During preheating, the surface temperature of the thermosetting resin film B is adjusted to 120°C and the surface temperature of the aggregate is adjusted to 130°C.

[0158] [Example 3]

[0159] In Example 1, the same operation was performed except for the following changes, to produce an FRP precursor C as a so-called prepreg blank.

[0160] (Change Point)

[0161] Instead of producing a thermosetting resin film A with a dry thickness of 50 μm, a thermosetting resin film (referred to as "thermosetting resin film C") with a dry thickness of 20 μm is produced, and this thermosetting resin film C is used instead of thermosetting resin film A.

[0162] Instead of obtaining a base-coated glass cloth α with a solid content of 8% by mass, a base-coated glass cloth (called base-coated glass cloth γ) is prepared by adjusting the solid content to 33% by mass. The minimum melt viscosity of the resin in the base-coated glass cloth γ is 126°C. This base-coated glass cloth γ is used instead of the base-coated glass cloth α.

[0163] [Comparative Example 1]

[0164] In Example 1, the glass cloth (basic weight 209 g / m²) was used directly without a pre-coating process [i.e., replacing the base-coated glass cloth α]. 2 [IPC#7628, substrate width 530mm: manufactured by Nan Ya Plastics Co., Ltd.] In addition, the same operation was performed to produce the FRP precursor W.

[0165] [Comparative Example 2]

[0166] In Example 2, the glass cloth (basic weight 48 g / m²) was used directly without a pre-coating process [i.e., replacing the primer-coated glass cloth β]. 2 [IPC#1080, substrate width 530mm: manufactured by Nitto Boshoku Co., Ltd.], and otherwise, the same operation was performed to produce FRP precursor X.

[0167] [Reference Example 1]

[0168] In Example 2, instead of preparing a thermosetting resin film B with a dried thickness of 40 μm, a thermosetting resin film (referred to as "thermosetting resin film 1") with a dried thickness of 45 μm is used. The minimum melt viscosity is 130°C. The glass cloth (basis weight 48 g / m³) is used in place of the film. 2 IPC#1080, substrate width 530mm: manufactured by Nitto Boshoku Co., Ltd., using glass cloth (basic weight 24g / m²). 2 IPC#1037, substrate width 530mm (manufactured by Nitto Boshoku Co., Ltd.), without pre-coating, the same operation is performed to produce FRP precursor Y.

[0169] The resin varnish 1 and the thermosetting resin film mentioned above are summarized in Table 1 below, the glass cloth used in each example is summarized in Table 2, and the manufacturing conditions of the FRP precursor in each example are summarized in Table 3 below.

[0170] In addition, resin samples were collected from the surface of the FRP precursors prepared in each example and measured using a rheometer (AR-200ex; manufactured by TAInstrument JAPAN Co., Ltd., φ20mm fixture) at a heating rate of 3°C / min. The lowest melt viscosity obtained is summarized in Table 4.

[0171] [Table 1]

[0172] Table 1

[0173] solid component specific gravity Volume ratio of filler material (%) Resin varnish 1 (for pre-coating process) 1.32 1.8 All thermosetting resin film 1.72 37.3

[0174] [Table 2]

[0175] Table 2: Types of Fiberglass Cloth

[0176]

[0177] [Table 3]

[0178] Table 3: Regarding Equation (1)

[0179]

[0180] [Table 4]

[0181] Table 4

[0182]

[0183] [Evaluation Method]

[0184] The FRP precursors obtained in each case were measured and evaluated as follows.

[0185] It should be noted that since the measurement and evaluation methods of Examples 1 and 3 and Comparative Example 1 are different from those of Examples 2, Comparative Example 2 and Reference Example 1, they will be described in turn.

[0186] (1. Determination and evaluation methods of Examples 1 and 3 and Comparative Example 1)

[0187] First, the FRP precursors prepared in Examples 1 and 3 and Comparative Example 1 were cut to a length of 530 mm and four pieces were stacked. Copper foil (GTS-MP-18, manufactured by Furukawa Electric Corporation) was stacked on both sides of the resulting material and clamped in an SUS mirror panel. The material was heated and formed at a product pressure of 3.0 MPa and a product temperature of 185°C for 70 minutes to produce a copper-clad laminate for evaluation with a thickness of 0.8 mm. The following measurements and evaluations were performed.

[0188] (1-1) Evaluation of the heat resistance of solder

[0189] Using copper-clad laminates for evaluation, the solder heat resistance was tested according to JIS C6481 (1996) 5.5. The appearance of the samples after solder treatment was visually observed, and the evaluation was carried out according to the following criteria. The results are shown in Table 5.

[0190] A: It caused expansion.

[0191] C: No expansion occurred.

[0192] (1-2) Evaluation of formability

[0193] The copper foil on both sides of the copper-clad laminate was etched using a hydrochloric acid-acid ferric chloride solution. The appearance of the etched laminate surface was visually observed, and the evaluation was performed according to the following criteria. The results are shown in Table 5.

[0194] A: No blur can be observed.

[0195] C: Blurring was observed.

[0196] (1-3) Determination of thermal conductivity

[0197] The thermal conductivity of the etched laminates prepared in “(1-2) Evaluation of Formability” above was determined according to the flash method of JIS R1611 (2010) 6.2. The results are shown in Table 5.

[0198] (2. Measurement and evaluation methods of Example 2, Comparative Example 2 and Reference Example 1)

[0199] Then, the FRP precursors prepared in Example 2, Comparative Example 2 and Reference Example 1 were cut to a length of 530 mm.

[0200] Next, after forming the inner layer pattern as shown in Fig. 6.4-19 in JPCA-UB-01 7.5.5 on a 510mm square copper-clad laminate (MCL-E-679FG, 0.2mm thick, with 35μm thick copper foil on both sides, manufactured by Showa Denko Materials Co., Ltd.), a copper surface roughening treatment (CZ-8101, etching amount (gravimetric method) 1.5μm, manufactured by MEC Co., Ltd.) is performed to produce the inner layer substrate.

[0201] On both sides of the aforementioned inner substrate, one piece of the aforementioned FRP precursor, cut to a length of 530mm, is placed. Copper foil (GTS-MP-12: manufactured by Furukawa Electric Industries, Ltd.) is placed on its outer side, and then it is clamped with a SUS mirror panel and held at a product pressure of 2.5MPa and a maximum temperature of 185°C for 90 minutes, thereby producing a 4-layer copper-clad laminate with a thickness of 0.4mm. The pattern of Fig. 6.4-19 described in JPCA-UB-01 7.5.5 is also formed on the outer layer to obtain a multilayer printed circuit board (4-layer board).

[0202] (2-1) Evaluation of the heat resistance of solder

[0203] Multilayer printed circuit boards (4-layer boards) were tested according to JPCA-UB-01 7.5.5.1 at a solder bath temperature of 288°C. The appearance of the samples after the test was visually observed, and the evaluation was carried out according to the following criteria. The results are shown in Table 5.

[0204] A: It caused expansion.

[0205] C: No expansion occurred.

[0206] (2-2) Evaluation of formability

[0207] The outermost copper foil of the multilayer printed circuit board (4-layer board) was removed using a hydrochloric acid-acid ferric chloride solution. The embedding (formability) of the inner layer pattern of the FRP precursor was visually observed and evaluated according to the following criteria. The results are shown in Table 5.

[0208] A: No blur can be observed.

[0209] C: Blurring was observed.

[0210] [Table 5]

[0211] Table 5

[0212]

[0213] In Table 5, Examples 1 and 3 can be compared with Comparative Example 1, and Examples 2 and Comparative Example 2 can be compared with Reference Example 1.

[0214] The solder of the FRP precursors obtained in the manufacturing methods of Examples 1-3 exhibits excellent heat resistance and formability. This can be presumably due to the fact that there is no localized increase in the filler material ratio of the resin layer near the surface of the glass cloth, and high viscosity and poor flowability do not occur, thus suppressing the deterioration of formability during lamination.

[0215] On the other hand, the FRP precursor obtained in the manufacturing method of Comparative Example 1 has insufficient solder heat resistance and formability compared to the FRP precursors obtained in the manufacturing methods of Examples 1 and 3 (see Table 5). Furthermore, the FRP precursor obtained in the manufacturing method of Comparative Example 2 has insufficient solder heat resistance and formability compared to the FRP precursor obtained in the manufacturing method of Example 2 (see Table 5).

[0216] However, the solder heat resistance and formability of the FRP precursor obtained in the manufacturing method of Reference Example 1 are excellent. However, the results show that, as shown in Table 2, when the aggregate buildup thickness is small, there is a tendency for the solder heat resistance and formability to decrease, which is not normally observable. When the aggregate buildup thickness is large, the effect of this embodiment is easily observed.

[0217] Explanation of reference numerals in the attached figures

[0218] 100 Pre-coating device, 200 FRP precursor manufacturing device used after pre-coating process, 2 Aggregate feeding device, 2' Feeding device for pre-coated aggregate, 3 Resin film feeding device, 4 Protective film peeling mechanism, 5 Protective film winding device, 6 Sheet heating and pressurizing device (film pressing method), 7 Sheet pressurizing and cooling device, 8 Winding device for pre-coated aggregate, 9 FRP precursor winding device, 10a Preheating mechanism, 10b Preheating mechanism, 11a Preheating mechanism, 11b Preheating mechanism, 17 Drying Machine, 40 aggregate, 40a one surface of aggregate (one surface of two surfaces of aggregate), 40b other surface of aggregate (the other surface of two surfaces of aggregate), 41 pre-coated aggregate, 41a one surface of pre-coated aggregate (one surface of two surfaces of aggregate), 41b another surface of pre-coated aggregate (the other surface of two surfaces of aggregate), 50 resin film with protective film, 52 protective film, 54 resin film, 54a aggregate side film surface, 60 FRP precursor.

Claims

1. A method for manufacturing an FRP precursor, comprising: The steps of pre-coating sheet aggregate with filler content of less than 5% by volume in resin varnish, and... The step of fusion bonding a pair of resin films, each containing more than 30% by volume of filler material, to the two surfaces of the aggregate after the pre-coating step.

2. The method for manufacturing the FRP precursor according to claim 1, wherein, In the pre-coating step, the amount of resin varnish used satisfies the following formula (1). The units for the volume, bulk volume, and true volume of the solid components are cm. 3 .

3. The method for manufacturing the FRP precursor according to claim 1 or 2, wherein, The steps for performing the melt bonding include the following steps for film pressing: The steps for membrane lamination are as follows: Under normal pressure, one surface of the resin membrane in the pair of resin membranes that serves as the aggregate side is laminated to one of the two surfaces of the aggregate, and the other surface of the other resin membrane in the pair of resin membranes that serves as the aggregate side is laminated to the other surface of the aggregate to obtain the FRP precursor.

4. The method for manufacturing the FRP precursor according to claim 3, wherein, Prior to the membrane pressing step, the process also includes a step of preheating the aggregate-side membrane surface of the two surfaces of the resin membrane.

5. The method for manufacturing the FRP precursor according to claim 3 or 4, wherein, Before performing the membrane pressing step, a step of preheating both surfaces of the aggregate is also included.

6. The method for manufacturing the FRP precursor according to any one of claims 1 to 5, wherein, The aggregate has a buildup thickness of 30 μm or more.

7. The method for manufacturing the FRP precursor according to any one of claims 1 to 6, wherein, The average particle diameter of the filler material contained in the resin varnish is 0.1 μm to 10 μm.

8. The method for manufacturing the FRP precursor according to any one of claims 1 to 7, wherein, The resin film is a thermosetting resin film.

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