JP2024009133A - Production method for frp precursor, frp precursor, laminated board, multilayer printed wiring board and semiconductor package - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a production method for an FRP precursor having excellent productivity, an FRP precursor produced by the production method, and a laminated board, a multilayer printed wiring board, and a semiconductor package using the FRP precursor.

SOLUTION: A production method for an FRP precursor in which a sheet-like aggregate is impregnated with a thermosetting resin film by pressure welding includes a step of performing pressure welding impregnation of the thermosetting resin film from only one surface of the sheet-like aggregate. The FRP precursor is produced by the production method. The FRP precursor is used for a laminated board, a multilayer printed wiring board, and a semiconductor package.

SELECTED DRAWING: None

COPYRIGHT: (C)2024,JPO&INPIT

Description

The present invention relates to a method for producing an FRP precursor, a method for producing an FRP precursor, a laminate, a multilayer printed wiring board, and a semiconductor package.

FRP (Fiber Reinforced Plastics) is a composite material that uses fibrous materials with high elastic modulus, such as fibers, as aggregate, and places this aggregate in a base material (matrix) such as plastic to improve strength. It is an inexpensive, lightweight, and highly durable material that takes advantage of its weather resistance, heat resistance, chemical resistance, and light weight.
Taking advantage of these performances, FRP is used in a wide range of fields. For example, FRP is used as a structural material for housing equipment, ships, vehicles, aircraft, etc. because it has good formability and high strength. Furthermore, due to its insulating properties, it is also used in the field of electronic components such as electrical devices and printed wiring boards.

When FRP is used for printed wiring boards, the thickness of FRP is required to be thinner than the thickness of FRP for other uses. Further, FRP for printed wiring boards is required to have high specifications such as a narrow range of thickness variation after molding and no voids.
Therefore, most FRPs for printed wiring boards are manufactured by the hand lay-up (HLU) method. The hand lay-up method is a manufacturing method in which a varnish containing a resin dissolved in a solvent is applied to the aggregate using a coating machine, etc., and then heated and dried to remove the solvent and heat cure the resin (for example, patented (See Reference 1).

However, when using non-calendered aramid non-woven fabric, thin glass paper, thin woven fabric, etc. as aggregate, these aggregates have low strength, so when narrowing the coater gap to adjust the amount of resin applied, Workability is poor because the aggregate may tear into pieces, or when drying, heat curing, etc. after application, the weight of the aggregate exceeds the load capacity of the aggregate, resulting in poor workability.
Furthermore, in FRP for printed wiring boards, it is necessary to achieve both high accuracy in the thickness after lamination and the ability to fill the inner layer circuit pattern with resin (moldability). Therefore, we can produce multiple types of FRP precursors using one type of aggregate, such as those with different amounts of resin attached to the aggregate by a few percent by mass, those with different curing times of thermosetting resin, and those that are a combination of these. It is complicated and has to be done. Furthermore, since each coating is manufactured under different coating conditions, there is a large loss of materials used in manufacturing.

Therefore, instead of applying thermosetting resin directly to the aggregate, a resin film made of thermosetting resin is prepared in advance, and the sheet-shaped aggregate and resin film are heated and pressurized. A method for producing an FRP precursor by pressure impregnation has been studied (see, for example, Patent Document 2).

Japanese Patent Application Publication No. 01-272416 Japanese Patent Application Publication No. 2011-132535

In the method of pressure-impregnating aggregate with a resin film, a method of pressure-impregnating a pair of resin films from both sides of sheet-like aggregate (hereinafter also referred to as "double-sided pressure impregnation method") is mainstream.
However, according to the double-sided pressure-contact impregnation method, two resin films made with half the amount of resin ultimately required are required as the resin films to be pressure-contacted to both sides. That is, it is necessary to prepare a resin film twice as long as the FRP precursor to be produced, resulting in poor productivity and yield. Furthermore, when producing a resin film using a small amount of resin, the heat during drying is easily transmitted to the resin and curing progresses, so the drying conditions of the applied varnish must be strictly controlled, making the work complicated.

A resin film is usually manufactured by coating a support with a varnish in which a thermosetting resin is dissolved in an organic solvent, and then drying the varnish. At this time, in order to improve the productivity of the FRP precursor, it is desirable to dry it at a higher temperature than the boiling point of the solvent and dry it in a short time. On the other hand, from the viewpoint of impregnating into the aggregate, it is desirable to dry the varnish at a low temperature, moderately suppress the progress of hardening of the resin film, and maintain the minimum melt viscosity low. In other words, in order to improve the productivity of FRP precursors, it is necessary to both suppress the minimum melt viscosity of the resulting resin film and quickly remove the solvent during drying, but it is necessary to achieve both. The heating conditions required for this are contradictory and difficult to achieve.

The present invention has been made in view of the above problems, and provides a method for producing an FRP precursor with excellent productivity, an FRP precursor produced by the production method, and a laminate and multilayer plate using the FRP precursor. Our objective is to provide printed wiring boards and semiconductor packages.

As a result of extensive research to solve the above problems, the present inventors have found that the above problems can be solved by the present invention described below, and have completed the present invention. That is, the present invention relates to the following [1] to [12].
[1] A method for manufacturing an FRP precursor in which a thermosetting resin film is heated and pressure-impregnated into a sheet-like aggregate, the method comprising: applying pressure-impregnating the thermosetting resin film to one side of the sheet-like aggregate; A method for manufacturing an FRP precursor, including a step of manufacturing only from scratch.
[2] The method for producing an FRP precursor according to [1] above, wherein the pressure-contact impregnation of the thermosetting resin film is performed by lamination.
[3] The method for producing an FRP precursor according to [1] or [2] above, wherein the thermosetting resin film has a minimum melt viscosity of 500 to ,000 mPa·s.
[4] The method for producing an FRP precursor according to any one of [1] to [3] above, wherein the aggregate has an air permeability of 110 cc/cm ² /sec or more.
[5] The method for producing an FRP precursor according to any one of [1] to [4] above, wherein the thermosetting resin film is pressure-impregnated into the sheet-like aggregate at a linear pressure of 0.1 to 1 MPa.
[6] The ratio of the thickness of the thermosetting resin film to the sheet aggregate [thermosetting resin film/sheet aggregate] is 1.1 to 2.5, [1] ] to [5]. The method for producing an FRP precursor according to any one of [5].
[7] The thermosetting resin film is a first support-attached thermosetting resin film having a first support on one surface,
Arranging the first support-attached thermosetting resin film on the one surface of the sheet-like aggregate such that the thermosetting resin film is on the one surface side of the sheet-like aggregate. ,
With a second support disposed on the other surface of the sheet-like aggregate,
The method for producing an FRP precursor according to any one of [1] to [6] above, wherein the thermosetting resin film is impregnated with pressure.
[8] The method for producing an FRP precursor according to [7] above, wherein the first support material and the second support material are the same.
[9] An FRP precursor produced by the method for producing an FRP precursor according to any one of [1] to [8] above.
[10] A laminate obtained by laminating and molding the FRP precursor described in [9] above.
[11] A multilayer printed wiring board manufactured using the laminate according to [10] above.
[12] A semiconductor package comprising a semiconductor mounted on the multilayer printed wiring board according to [11] above.

According to the present invention, there is provided a method for producing an FRP precursor with excellent productivity, an FRP precursor produced by the method, and a laminate, a multilayer printed wiring board, and a semiconductor package using the FRP precursor. Can be done.

1 is a conceptual diagram of an FRP precursor manufacturing method and an FRP precursor manufacturing apparatus according to the present invention.

[Method for manufacturing FRP precursor]
The method for producing an FRP precursor of the present embodiment is a method for producing an FRP precursor in which sheet-like aggregate is pressure-impregnated with a thermosetting resin film, and the method includes pressure-impregnating the thermosetting resin film into the sheet-like aggregate. This is a method for producing an FRP precursor using only one side of aggregate.
Hereinafter, the sheet-like aggregate may be simply abbreviated as "aggregate", and the thermosetting resin film may be simply abbreviated as "resin film". The "resin film" does not include the protective film and support described below.
Further, a method in which the thermosetting resin film is impregnated by pressure from only one side of the sheet-like aggregate is sometimes referred to as a "single-sided pressure impregnation method."
Furthermore, in the present invention, "press contact" means applying pressure while in contact.

In the method for producing an FRP precursor of the present embodiment, the thermosetting resin film is a first support-attached thermosetting resin film having a first support on one surface,
Arranging the first support-attached thermosetting resin film on the one surface of the sheet-like aggregate such that the thermosetting resin film is on the one surface side of the sheet-like aggregate. ,
With a second support disposed on the other surface of the sheet-like aggregate,
It is preferable that the thermosetting resin film be impregnated with pressure.
Hereinafter, with reference to FIG. 1, a method for manufacturing an FRP precursor according to the present embodiment will be described.

The FRP precursor manufacturing apparatus 1 impregnates the aggregate 40 with a resin film 54 under pressure from one side, and presses the second support 56 onto the aggregate 40 from the other side.
The purpose of the second support 56 is to prevent the resin from seeping out from the surface of the aggregate 40 on which the resin film 54 is not disposed when the resin film 54 is impregnated with pressure, and to prevent the resulting FRP precursor It is used for the purpose of stabilizing the surface condition of.
The FRP precursor manufacturing apparatus 1 is placed under normal pressure. The method for manufacturing an FRP precursor according to the present embodiment can be performed using the FRP precursor manufacturing apparatus 1.

The FRP precursor manufacturing apparatus 1 includes an aggregate delivery device 2, a resin film delivery device 3, a second support delivery device 3', a sheet heating and pressing device 6, a sheet pressing and cooling device 7, An FRP precursor winding device 8 is provided. Preferably, the FRP precursor manufacturing apparatus 1 further includes a protective film peeling mechanism 4 and a protective film winding device 5. The FRP precursor manufacturing apparatus 1 also includes an aggregate heating device (not shown) for heating the aggregate before being sent to the sheet heating and pressing device 6; It may have a resin film heating device (not shown) for heating the resin film.

The aggregate delivery device 2 is a device that rotates a roll around which sheet-like aggregate 40 is wound in a direction opposite to the winding direction, and sends out the aggregate 40 wound around the roll. In FIG. 1, the aggregate delivery device 2 sends the aggregate 40 toward the sheet heating and pressing device 6 from below the roller.

The resin film delivery device 3 applies a predetermined tension to a roll around which a resin film 50 with a first support and a protective film (hereinafter also simply referred to as "multilayer film 50") is wound, and to the multilayer film 50 to be delivered. This device has a support mechanism that rotatably supports the roll, rotates the roll around which the multilayer film 50 is wound in a direction opposite to the winding direction, and sends out the multilayer film 50 wound around the roll. The multilayer film 50 includes a resin film 54, a protective film 52 laminated on a surface 54a on the aggregate 40 side of both surfaces of the resin film 54, and a first protective film 52 laminated on a surface 54b on the opposite side to the aggregate 40. It is a sheet-like multilayer film including a support body 53.
The resin film delivery device 3 is located on the surface 40a side of the delivered aggregate 40, and protects the multilayer film 50 from below the roller so that the protective film 52 is on the delivered aggregate 40 side. This is a device that feeds the film toward the film peeling mechanism 4.

The second support delivery device 3' includes a roll around which the second support 56 is wound, and a support mechanism that rotatably supports the roll while applying a predetermined tension to the second support 56 to be delivered. This device rotates the roll around which the second support 56 is wound in a direction opposite to the winding direction, and sends out the second support 56 wound around the roll.
The second support delivery device 3' is located on the back surface 40b side of the sent out aggregate 40, and is a device that sends out the second support 56 from above the roller toward the sheet heating and pressing device 6.

The protective film peeling mechanism 4 is a turning roller located on the surface 40a side of the fed aggregate 40. The protective film peeling mechanism 4 receives the multilayer film 50 sent out from the resin film sending device 3 and advancing toward the protective film peeling mechanism 4 on the surface of a rotating turning roller. Furthermore, by advancing the first support-attached resin film 55 of the multilayer film 50 toward the sheet heating and pressing device 6 and advancing the protective film 52 toward the protective film winding device 5, the multilayer film This is a mechanism for peeling off the protective film 52 from the protective film 50. As a result, the aggregate side film surface 54a of the resin film 54 is exposed.

The protective film winding device 5 is located on the surface 40a side of the sent-out aggregate 40, and is a winding device that winds up the protective film 52 peeled off by the protective film peeling mechanism 4.

The sheet heating and pressing device 6 includes a pair of heating compression rollers and a compression force applying mechanism (not shown) that applies compression force to the pair of heating compression rollers. The pair of heating compression rollers has a heating body inside so that they can be heated at a predetermined set temperature.
The sheet heating and pressing device 6 presses and impregnates the aggregate 40 with a resin film 54 using a pair of rotating heating compression rollers to form a sheet-shaped FRP precursor 60 (film pressing process), and also impregnates the FRP precursor. 60 is sent out toward the sheet pressure cooling device 7.
At this time, the first support-attached resin film 55 is laminated on the aggregate 40 so that the aggregate-side film surface 54a of the resin film 54 adheres to the surface 40a of the aggregate 40, and the second support The FRP precursor 60 is formed by laminating the body 56 on the aggregate 40 so as to adhere to the back surface 40b of the aggregate 40.
The temperature of the heated pressure roller is preferably in the range of +2 to 30°C, more preferably in the range of +4 to 20°C, above the lowest melt viscosity temperature of the resin film used. The method for measuring the minimum melt viscosity temperature of a resin film is as described below.
Furthermore, the linear pressure when pressing and impregnating the sheet aggregate with the resin film is preferably 0.1 to 1 MPa, more preferably 0.2 to 0.7 MPa, and even more preferably 0.3 to 0.5 MPa.
The FRP precursor 60 sent out from the sheet heating and pressing device 6 is in a high temperature state.

The sheet pressurizing and cooling device 7 includes 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 compress and cool the high-temperature FRP precursor 60 sent out from the sheet heating and pressing device 6 with the pair of rotating cooling compression rollers, and send it out to the FRP precursor winding device 8.

The FRP precursor winding device 8 includes a roll that winds up the sheet-like FRP precursor 60 sent out from the sheet pressure cooling device 7, and a drive mechanism (not shown) that rotates the roll.

The FRP precursor manufacturing apparatus 1 described above operates as follows.

First, the sheet-like aggregate 40 is sent out from the aggregate delivery device 2 toward the sheet heating and pressing device 6 . At this time, the front surface 40a and back surface 40b of the aggregate 40 are exposed.
The front surface 40a and back surface 40b of the aggregate 40 sent out may be heated by an aggregate heating device (not shown) under normal pressure.

On the other hand, the resin film sending device 3 protects the first support and the resin film 50 with a protective film (multilayer film 50) from below the roller so that the protective film 52 is on the fed aggregate 40 side. The film is sent out toward the film peeling mechanism 4.
Further, the second support delivery device 3' sends out the second support 56 toward the sheet heating and pressing device 6 from above the roller.

When the sent-out multilayer film 50 is hung on a turning roller, which is the protective film peeling mechanism 4, and turned, the protective film 52 is peeled off so that the aggregate side film surface 54a is exposed. The peeled off protective film 52 is wound up by the protective film winding device 5. The first support-attached resin film 55 from which the protective film 52 has been peeled off is sent out toward the sheet heating and pressing device 6 .

The aggregate 40 sent out from the aggregate delivery device 2, the first resin film 55 with a support body 55 sent out from the protective film peeling mechanism 4, and the second support body 56 are separated by the sheet heating and pressing device 6. It fits between a pair of heated compression rollers. At this time, of the first support-attached resin film 55, the aggregate-side film surface 54a of the resin film 54 is laminated on the front surface 40a of the aggregate 40, and the second support 56 is laminated on the back surface 40b of the aggregate 40. Laminate.
Then, under normal pressure, the resin film 54 is pressure-impregnated into the aggregate 40 using the sheet heating and pressing device 6 to obtain an FRP precursor 60. At this time, by controlling the temperature of the heating body inside the pair of heating compression rollers, the pair of heating compression rollers are maintained at a predetermined temperature, and pressure is applied while heating during the film pressing process.
According to the embodiment described above, an FRP precursor 60 having supports on both sides can be obtained, in which the first support 53, the FRP precursor 60, and the second support 56 are laminated in this order.

The FRP precursor 60 sent out from the sheet heating and pressing device 6 is further pressurized and cooled by the sheet pressing and cooling device 7.
The FRP precursor 60 sent out from the sheet pressure cooling device 7 is wound up by the FRP precursor winding device 8.

In the above example, one resin film is laminated to the aggregate, but two or more resin films may be laminated to the aggregate. At this time, two or more resin films having different degrees of thermosetting, different compositions, etc. may be used in combination.

The obtained FRP precursor may be cut into any size, adhered to a predetermined object, and heat-cured. Further, the FRP precursor may be used roll-to-roll.

The FRP precursor manufactured by the FRP precursor manufacturing apparatus 1 will be explained.

<Sheet aggregate>
As the aggregate used in the manufacturing method of this embodiment, well-known aggregates used in various electrically insulating material laminates can be used. The aggregate is preferably a fiber base material, and examples of the fiber base material include natural fibers such as paper and cotton linters; inorganic fibers such as glass fibers and asbestos; aramid, polyimide, polyvinyl alcohol, polyester, and tetrafluoroethylene. , organic fibers such as acrylic; and mixtures thereof. Among these, glass cloth is preferred from the viewpoint of flame retardancy. Examples of the glass cloth include glass cloth using E glass, C glass, D glass, S glass, etc.; glass cloth made by bonding short fibers with an organic binder; and a mixture of glass fiber and cellulose fiber.
These fiber substrates have shapes such as woven fabrics, nonwoven fabrics, raw binders, chopped strand mats, or surfacing mats. The material and shape of the aggregate are selected depending on the intended use and performance of the molded product, and one type may be used alone, or two or more types of materials and shapes may be combined as necessary. Good too.

The thickness of the sheet aggregate is preferably 3 to 50 μm, more preferably 5 to 20 μm, and even more preferably 7 to 15 μm, from the viewpoint of reducing the thickness of the printed wiring board and the strength of the obtained FRP precursor.

The air permeability (cc/cm ² /sec) of the sheet aggregate is preferably 110 cc/cm ² /sec or more, more preferably 200 cc/cm ² /sec or more, and 260 cc/cm from the viewpoint of impregnating the resin film. ² /sec or more is more preferable. Moreover, from the viewpoint of the strength of the obtained FRP precursor, it may be 500 cc/cm ² /sec or less.
The air permeability of the sheet aggregate is measured using a Frazier air permeability tester manufactured by Toyo Seiki Seisakusho Co., Ltd. using a sample of sheet aggregate of 300 mm x 1260 mm.

<Thermosetting resin film>
The thermosetting resin film used in the method for producing an FRP precursor of the present embodiment is a film containing a thermosetting resin, and is a film containing a thermosetting resin or a composition containing a thermosetting resin (hereinafter referred to as "thermosetting resin"). (also referred to as "resin composition") is made into a film.

Examples of thermosetting resins include epoxy resins, phenol resins, urea resins, furan resins, and the like. Among these, epoxy resins are preferred from the viewpoints of workability, ease of handling, and price. One type of thermosetting resin may be used alone, or two or more types may be used in combination.
As the epoxy resin, a difunctional or higher functional epoxy resin is preferred. Examples of bifunctional or higher-functional epoxy resins 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; phenol novolac type epoxy resins, cresol novolac type epoxy resins , bisphenol A novolac type epoxy resins, aralkyl novolak type epoxy resins, and other novolak type epoxy resins; diglycidyl etherified products of polyfunctional phenols; and hydrogenated products thereof.

When using an epoxy resin as the thermosetting resin, an epoxy resin curing agent may be used. The epoxy resin curing agents may be used alone or in combination of two or more.
Examples of the epoxy resin curing agent include phenol resins, amine compounds, acid anhydrides, boron trifluoride monoethylamine, isocyanates, dicyandiamide, urea resins, and among these, phenol resins are preferred.
Examples of phenolic resins include novolac type phenolic resins such as phenol novolac resins and cresol novolac resins; naphthalene type phenolic resins, high ortho type novolac phenolic resins, terpene-modified phenolic resins, terpene-phenol modified phenolic resins, aralkyl-type phenolic resins, and dicyclopentadiene-type phenolic resins. Examples include phenol resin, salicylaldehyde type phenol resin, and benzaldehyde type phenol resin.
The blending amount of the epoxy resin curing agent is preferably such that the reactive group equivalent ratio of the curing agent is 0.3 to 1.5 equivalents to 1 epoxy equivalent of the epoxy resin. When the amount of the epoxy resin curing agent is within the above range, the degree of curing can be easily controlled and productivity can be improved.

The thermosetting resin composition used for forming the resin film may further contain a curing accelerator. The curing accelerator may be used alone or in combination of two or more.
Examples of the curing accelerator include imidazole compounds, organic phosphorus compounds, tertiary amines, and quaternary ammonium salts. The imidazole compound may be a latent imidazole compound obtained by masking the secondary amino group of imidazole with acrylonitrile, isocyanate, melamine, acrylate, or the like. The imidazole compounds used here include imidazole, 2-methylimidazole, 4-ethyl-2-methylimidazole, 2-phenylimidazole, 2-undecylimidazole, 1-benzyl-2-methylimidazole, 2-heptadecylimidazole. , 4,5-diphenylimidazole, 2-methylimidazoline, 2-ethyl-4-methylimidazoline, 2-undecylimidazoline, 2-phenyl-4-methylimidazoline and the like. Furthermore, a photoinitiator that generates radicals, anions, or cations by photolysis to initiate curing may be used.
The blending amount of the curing accelerator is preferably 0.01 to 20 parts by weight per 100 parts by weight of the thermosetting resin. When the amount is 0.01 parts by mass or more, a sufficient curing accelerating effect is obtained, and when it is 20 parts by mass or less, the storage stability of the thermosetting resin composition and the physical properties of the cured product are excellent, and the cost efficiency is also excellent.

The thermosetting resin composition may further contain a filler in order to improve impermeability and abrasion resistance, and to increase the weight. One type of filler may be used alone, or two or more types may be used in combination.
Fillers include oxides such as silica, aluminum oxide, zirconia, mullite, and magnesia; hydroxides such as aluminum hydroxide, magnesium hydroxide, and hydrotalcite; nitride ceramics such as aluminum nitride, silicon nitride, and boron nitride. natural minerals such as talc, montmorillonite, saponite; metal particles, carbon particles, etc.

Fillers have a wide range of specific gravity, ranging from those with low specific gravity to those with high specific gravity compared to resins, so it is preferable to consider the amount of filler added in terms of volume percentage rather than parts by mass.
The amount of the filler to be added varies greatly depending on the purpose of addition, but is preferably in the range of 0.1 to 65% by volume based on the solid volume of the thermosetting resin composition. When the amount is 0.1% by volume or more, it is sufficiently effective when added for the purpose of coloring and opaqueness. Further, when the content is 65% by volume or less, increase in viscosity can be suppressed and the amount can be increased without deteriorating workability and adhesiveness.
Here, the solid content in this specification refers to components in the composition other than moisture and volatile substances such as organic solvents described below. That is, the solid content includes liquid, starch syrup-like, and wax-like substances at room temperature around 25°C, and does not necessarily mean solid content.

In addition to the above-mentioned components, the thermosetting resin composition may contain other components as necessary within a range that does not impede the effects of the present invention. For example, a flexible material may be added to the cured resin material in order to impart resin tackiness and improve adhesion during adhesion. Flexible materials include polystyrene, polyolefin, polyurethane, acrylic resin, acrylonitrile rubber, polyvinyl alcohol, materials modified with epoxy or carboxyl groups to incorporate them into the curing system, and materials that are made into large molecules by reacting epoxy resins in advance. Examples include phenoxy.

In order to achieve uniformity, the thermosetting resin composition is preferably in the form of a varnish dissolved and/or dispersed in an organic solvent. One type of organic solvent may be used alone, or two or more types may be used in combination.
Examples of organic solvents include acetone, methyl ethyl ketone, toluene, xylene, cyclohexanone, 4-methyl-2-pentanone, ethyl acetate, ethylene glycol monoethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, and tripropylene glycol monomethyl ether. , N,N-dimethylformamide, N,N-dimethylacetamide and the like.

A resin film can be manufactured by applying a thermosetting resin composition obtained by blending the above-mentioned components onto a support, removing unnecessary organic solvents, and thermosetting the composition.
Note that the purpose of heat curing here is to bring the thermosetting resin composition into a so-called semi-cured (B-staged) state. It is preferable to semi-cure the resin composition.
The minimum melt viscosity of the resin film is preferably 500 to 3,000 mPa·s, more preferably 600 to 2,000 mPa·s, and still more preferably 700 to 1,000 mPa·s, from the viewpoint of improving the impregnation properties of the resin film. preferable.
The minimum melt viscosity temperature of the resin film is preferably 60 to 150°C, more preferably 80 to 130°C, and even more preferably 100 to 120°C, from the viewpoint of productivity of the FRP precursor.
Note that the minimum melt viscosity and minimum melt viscosity temperature can be measured by the method described in Examples.

The thickness of the resin film is preferably 5 to 40 μm, more preferably 10 to 30 μm, and even more preferably 15 to 25 μm, from the viewpoint of reducing the thickness of the printed wiring board and the strength of the obtained FRP precursor.

When laminating the resin film and the aggregate, the thickness of the resin film is preferably made thicker than the aggregate, taking into account the target thickness of the FRP precursor and the moldability during press molding. The ratio of the thickness of the resin film to the thickness of the aggregate [thermosetting resin film/sheet aggregate] is preferably 1.1 to 2.5, and 1.3 to 2.2 from the viewpoint of formability. More preferably, 1.5 to 2.0 is even more preferable.

<Support>
Examples of the support (first support) for the resin film include organic films such as polyethylene terephthalate (PET), biaxially oriented polypropylene (OPP), polyethylene, polyvinyl fluorate, and polyimide; copper, aluminum, and alloys of these metals. Film: Examples include films in which the surface of these organic films or metal films is subjected to mold release treatment with a mold release agent.

Examples of the second support include the same ones as the first support described above.
It is preferable that the first support and the second support are made of the same material. If the first support and the second support are made of the same material, the behavior during thermocompression bonding will be uniform on the front and back sides of the FRP precursor, and the thermal shrinkage and dimensional change rate of the support during thermocompression bonding will be reduced. It is possible to suppress the increase in residual stress on the product due to the difference and the occurrence of appearance defects such as wrinkles.

[Laminated board]
The laminate of this embodiment is a laminate obtained by laminating and molding the FRP precursor obtained by the method for producing an FRP precursor of this embodiment.
Examples of the laminate of this embodiment include a laminate containing the FRP precursor or an FRP obtained by curing the FRP precursor, and a metal-clad laminate having metal foil on the laminate. FRP obtained by curing an FRP precursor is FRP obtained by curing a B-staged (semi-cured) FRP precursor to C-stage (hardening), and the present invention also applies to the FRP. provide.

Specifically, the laminate of this embodiment can be manufactured by laminating one or more (preferably 2 to 20) FRP precursors stacked together under predetermined conditions. can. A substrate on which an inner layer circuit has been processed may be sandwiched between the FRP precursors. Through the lamination molding, the FRP precursor is cured (C-staged) and becomes FRP.
In addition, a metal-clad laminate can be obtained by laminating and forming one or more FRP precursors (preferably 2 to 20 sheets) and placing metal foil on one or both surfaces, preferably both surfaces. can be manufactured.

As the lamination conditions, known conditions used for manufacturing laminated boards used for printed wiring boards can be adopted. For example, a multistage press, a multistage vacuum press, a continuous molding machine, an autoclave molding machine, etc. can be used, and conditions can be adopted in which lamination is performed at a temperature of 100 to 250°C, a pressure of 0.2 to 10 MPa, and a heating time of 0.1 to 5 hours.

The thickness of the metal foil is preferably 40 μm or less, more preferably 1 to 40 μm, even more preferably 5 to 40 μm, even more preferably 5 to 35 μm, particularly preferably 5 to 25 μm, and most preferably 5 to 17 μm.

From the viewpoint of conductivity, the metal of the metal foil includes copper, gold, silver, nickel, platinum, molybdenum, ruthenium, aluminum, tungsten, iron, titanium, chromium, or at least one of these metal elements. Preferably, it is an alloy. As the alloy, copper-based alloys, aluminum-based alloys, and iron-based alloys are preferred. Examples of copper-based alloys include copper-nickel alloys. Examples of the iron-based alloy include iron-nickel alloy (42 alloy). Among these, copper, nickel, and 42 alloy are more preferable as metals, and copper is even more preferable from the viewpoint of availability and cost.

[Printed wiring board]
The printed wiring board of this embodiment is a printed wiring board manufactured using the laminate of this embodiment.
The printed wiring board of this embodiment can be manufactured, for example, by forming a wiring pattern on the laminate of this embodiment. Examples of methods for forming the wiring pattern include known methods such as a subtractive method, a fully additive method, a semi-additive process (SAP), and a modified semi-additive process (m-SAP). It will be done.

[Semiconductor package]
The semiconductor package of this embodiment is a semiconductor package formed by mounting a semiconductor on the printed wiring board of this embodiment.
The semiconductor package of this embodiment can be manufactured by mounting a semiconductor element such as a semiconductor chip or a memory at a predetermined position on the printed wiring board of this embodiment, and sealing the semiconductor element with a sealing resin or the like.

Next, the present invention will be explained in more detail with reference to the following examples, but these examples are not intended to limit the present invention.
In addition, the performance of the thermosetting resin and FRP precursor manufactured in each example was measured by the following method.

[Minimum melt viscosity of resin film]
Using the resin films obtained in each example as measurement samples, the minimum melt viscosity and minimum melt viscosity temperature were measured under the following conditions.
・Measuring equipment: AR2000ex (manufactured by TA Instruments)
・Measurement temperature range: 50-200℃
・Temperature increase rate: 3℃/min
・Test piece: 20mm circular tablet made of compressed resin from resin-coated film ・Load: 0.20N

[Impregnation of thermosetting resin into aggregate]
The surface of the FRP precursor obtained in each example was observed at 100 times magnification using an optical microscope, and the impregnability was evaluated based on the following criteria.
(Evaluation criteria)
A: There is no resin-unimpregnated portion in the aggregate.
B: There is a very small portion of the aggregate that is not impregnated with resin.
C: There is a small portion of the aggregate that is not impregnated with resin.
D: There are many parts of the aggregate that are not impregnated with resin, or the aggregate is not impregnated with resin, or the aggregate is exposed.

[Appearance of FRP precursor]
The surface of the FRP precursor obtained in each example was observed at 100 times magnification using an optical microscope, and the appearance was evaluated based on the following criteria.
(Evaluation criteria)
A: There is no abnormality in appearance.
B: There is a slight abnormality in appearance.
C: There are many abnormalities in appearance.

[Preparation of thermosetting resin varnish]
Preparation example 1
15 parts by mass of cyclohexane and 130 parts by mass of methyl ethyl ketone were added to 100 parts by mass of phenol novolac type epoxy resin (N-660; manufactured by DIC Corporation) and 60 parts by mass of cresol novolak resin (KA-1165; manufactured by DIC Corporation), and stirred. and dissolved. In addition, 180 parts by mass of aluminum hydroxide (CL-303; manufactured by Sumitomo Chemical Co., Ltd.) as an inorganic filler, 1 part by mass of a coupling agent (A-187; manufactured by Momentive Performance Materials), and an isocyanate mask as a curing accelerator. 2.5 parts by mass of imidazole (G8009L; manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) was added and stirred to dissolve and disperse to obtain a thermosetting resin varnish with a solid content concentration of 70% by mass.

[Manufacture of FRP precursor 1]
Examples 1 to 9
(1) Preparation of resin films A to C The thermosetting resin varnish obtained above was applied to a 580 mm wide PET film (G-2; manufactured by Teijin DuPont Films Ltd.) as a support with a coating width of 540 mm, and dried. After coating so that the thickness of the subsequent resin film was 20 μm, drying was performed under predetermined conditions to produce resin films A to C with supports.
Note that drying was performed until the amount of residual solvent in the resin film was 1.0% by mass or less, the minimum melt viscosity of resin film A was 1,500 mPa s, the minimum melt viscosity of resin film B was 700 mPa s, The drying conditions were adjusted so that the minimum melt viscosity of the resin film C was 2,500 mPa·s.

(2) Pressure impregnation step into aggregate Next, the resin film obtained above was coated with glass cloth (air permeability: as shown in Table 1, basis weight 10.2 g/m ² , IPC#1010, width 550 mm, thickness 11 μm, manufactured by Unitika Co., Ltd.), and with the same support as above applied to the other side of the glass cloth, a heated pressure roll was applied. The resin film was impregnated into the glass cloth under pressure under the laminating conditions shown in Table 1. Thereafter, it was cooled with a cooling roll and wound up to obtain an FRP precursor. Note that lamination was performed roll-to-roll, and the line speed was kept constant at 1.0 m/min.

Table 1 shows the evaluation results of the FRP precursors obtained in each example.

From Examples 1 to 3 in Table 1, Example 3 using a resin film with a minimum melt viscosity of 2,500 mPa・s, and Example 1 using a resin film with a minimum melt viscosity of 1,500 mPa・s or 750 mPa・s. It can be seen that samples 2 and 2 are better in impregnating into aggregate.
Furthermore, from Examples 4 to 7 in Table 1, it is clear that Examples 5 to 7, in which the pressure during pressure welding is 0.3 to 0.7 MPa, are more effective at impregnating the aggregate than Example 4, in which the pressure during pressure welding is 0.15 MPa. Among them, it can be seen that Example 5, in which the pressure at the time of pressure welding was 0.3 MPa, and Example 6, in which the pressure was 0.5 MPa, were excellent in the appearance of the FRP precursor.
Furthermore, from Examples 1, 8, and 9 in Table 1, the air permeability of the aggregate is higher than that of Example 8, which is 110 cc/cm ² /sec, and even 260 cc/cm ² /sec. It can be seen that Example 1, which has a permeability of cm ² /sec, has better ability to impregnate aggregates.

Next, the productivity of the FRP precursor by the manufacturing method of this embodiment was evaluated.

[Manufacture of FRP precursor 2]
Examples 10-13
(1) Preparation of resin films D to G The thermosetting resin varnish prepared in Preparation Example 1 was applied to a 580 mm wide PET film (G-2; manufactured by Teijin DuPont Films Ltd.) with a coating width of 540 mm, and after drying the resin The resin films D to G were coated to a film thickness of 20 μm or 10 μm and dried under the conditions shown in Table 2.
(2) Pressure impregnation process into aggregate The resin films D to G obtained above were coated with glass cloth (air permeability: 260 cc/cm ² /sec, basis weight 10.2 g/m ² , IPC#1010, width 550 mm, 11 μm thick, made by Unitika Co., Ltd.), and with the same support as above applied to the other side of the glass cloth, the glass cloth was sandwiched between heated pressure rolls, and the pressure at the time of pressure welding was applied. Lamination was carried out under conditions of 0.4 MPa and a heating roll temperature of 140° C., and the glass cloth was impregnated with the resin film under pressure. Thereafter, it was cooled with a cooling roll and wound up to obtain an FRP precursor. Note that lamination was performed roll-to-roll, and the line speed was kept constant at 1.0 m/min.

Table 2 shows the evaluation results of the FRP precursors obtained in each example.

In Table 2, from Example 10, the resin film with a thickness of 20 μm was dried at a high temperature of 150° C. for 2 minutes, and the solvent was sufficiently dried and removed, and the minimum melt viscosity was kept low. It can be seen that excellent impregnation into aggregate can be obtained.
On the other hand, from Example 11, when a resin film with a thickness of 10 μm is dried at a high temperature of 150° C. for 2 minutes for a short time, the minimum melt viscosity becomes high and the impregnability into aggregate is relatively low. It has become. In addition, from Example 13, when a resin film with a thickness of 10 μm is set at a low temperature of 120°C, drying for 5 minutes is required to bring the amount of residual solvent to a predetermined value. It can be seen that it takes more time to produce a resin film than some other resin films.
From this, it can be seen that the pressure impregnation of the resin film from only one side of the aggregate is better than the case of pressure impregnation of the resin film from both sides of the aggregate. It can be seen that since the thickness of the film can be increased, a resin film with excellent impregnation properties into aggregate can be produced in a short time, resulting in excellent productivity.

[Manufacture of FRP precursor 3]
Example 14, Comparative Example 1
Next, using the resin film D obtained above, we will calculate the production time when an FRP precursor is produced by press-impregnating the resin film from only one side of the aggregate, and the resin film F obtained above. The production time was compared with the production time when an FRP precursor was produced by pressure-contact impregnation of a resin film from both sides of the aggregate. The glass cloth, laminating conditions, etc. used here were the same as those in Example 1. The results are shown in Table 3.

Table 3 shows that the single-sided pressure impregnation method of this embodiment requires less time for coating during resin film production than the conventional double-sided pressure impregnation method, and can significantly shorten the production time of the FRP precursor. I understand.

1 FRP precursor manufacturing device 2 Aggregate delivery device 3 Resin film delivery device 3' Second support delivery device 4 Protective film peeling mechanism 5 Protective film winding device 6 Sheet heating and pressing device (film pressure welding means)
7 Sheet pressure cooling device 8 FRP precursor winding device 40 Aggregate 40a Surface of aggregate (one surface of aggregate, one of both surfaces of aggregate)
40b Back side of aggregate (other surface of aggregate, other of both surfaces of aggregate)
50 Resin film with first support and protective film (multilayer film)
52 Protective film 53 First support 54 Resin film 54a Surface of the resin film on the aggregate side (surface of the film on the aggregate side)
55 Resin film with first support 56 Second support 60 FRP precursor

Claims (12)

A method for producing an FRP precursor in which a thermosetting resin film is heated and pressure-impregnated into a sheet-like aggregate, the method comprising pressure-impregnating the thermosetting resin film from only one side of the sheet-like aggregate. A method for manufacturing an FRP precursor, including the steps. The method for producing an FRP precursor according to claim 1, wherein the pressure-contact impregnation of the thermosetting resin film is performed by lamination. The method for producing an FRP precursor according to claim 1 or 2, wherein the thermosetting resin film has a minimum melt viscosity of 500 to 3,000 mPa·s. The method for producing an FRP precursor according to any one of claims 1 to 3, wherein the aggregate has an air permeability of 110 cc/cm ² /sec or more. The method for producing an FRP precursor according to any one of claims 1 to 4, wherein the thermosetting resin film is pressure-impregnated into the sheet-like aggregate at a linear pressure of 0.1 to 1 MPa. Any one of claims 1 to 5, wherein the ratio of the thickness of the thermosetting resin film to the thickness of the sheet-like aggregate [thermosetting resin film/sheet-like aggregate] is 1.1 to 2.5. 2. The method for producing an FRP precursor according to item 1. The thermosetting resin film is a first support-attached thermosetting resin film having a first support on one surface,
Arranging the first support-attached thermosetting resin film on the one surface of the sheet-like aggregate such that the thermosetting resin film is on the one surface side of the sheet-like aggregate. ,
With a second support disposed on the other surface of the sheet-like aggregate,
The method for producing an FRP precursor according to any one of claims 1 to 6, wherein the thermosetting resin film is impregnated under pressure. The method for producing an FRP precursor according to claim 7, wherein the first support and the second support are made of the same material. An FRP precursor produced by the method for producing an FRP precursor according to any one of claims 1 to 8. A laminate obtained by laminating and molding the FRP precursor according to claim 9. A multilayer printed wiring board manufactured using the laminate according to claim 10. A semiconductor package comprising a semiconductor mounted on the multilayer printed wiring board according to claim 11.