TW201343740A - Prepreg and method for manufacturing prepreg - Google Patents

Abstract

The invention relates to a prepreg (1) comprising a fibrous substrate (2), a first resin layer (3) covering one side of the fibrous substrate (2) and being composed of a first resin composition, and a second resin layer (4) covering the other side of the fibrous substrate (2) and being composed of a second resin composition that is different from the first resin composition. The second resin layer (4) is impregnated in the fibrous substrate (2) throughout at least 90% of the thickness of the fibrous substrate (2) from the other side of the fibrous substrate (2).

Description

Prepreg and prepreg manufacturing method

The present invention relates to a method for producing a prepreg and a prepreg.

In recent years, in order to reduce the size and thickness of electronic components and electronic devices, it is required to reduce the size and thickness of circuit boards used. In order to cope with this demand, a circuit board having a multilayer structure has been used to make each layer thin.

In general, in order to thin a circuit board, a circuit pattern is formed on one surface of a prepreg, and a method of embedding the circuit pattern by another prepreg adjacent to the prepreg is used. Patent Document 1 discloses a prepreg suitable for a circuit board of such a configuration. Patent Document 1 discloses a prepreg in which two resin layers having different thicknesses are formed on both sides of a fiber base material.

[Previous Technical Literature] [Patent Literature]

Patent Document 1: Japanese Patent Laid-Open Publication No. 2004-216784

As described above, there is a method in which a circuit pattern is formed on one surface of a prepreg, and the circuit pattern is buried by another prepreg adjacent to the prepreg. In this case, a circuit pattern is formed on the resin layer on one side of the prepreg, and buried in the resin layer on the other side. The circuit pattern of the adjacent prepreg. Therefore, the resin layer on one side of the prepreg is required to have adhesion to the circuit pattern, and the resin layer on the other side is required to have embedding of the circuit pattern. That is, different characteristics are required for each of the two resin layers of the prepreg. In the prepreg described in Patent Document 1, since the thickness of one resin layer is thicker than the other resin layer, a circuit pattern can be buried in the resin layer having a relatively large thickness. However, in the prepreg described in Patent Document 1, since the two resin layers are composed of the same resin composition, it is difficult to satisfy the above two different characteristics.

In order to satisfy the different characteristics of the resin layer on the one side of the prepreg and the resin layer on the other side, the inventors of the present invention proposed to form the resin layers with different resin compositions. However, it has been found that when two or more of the above resin compositions are impregnated into the fibrous base material, it is necessary to have good impregnation properties to the fibrous base material, and to limit the design of each resin composition to each resin. It is difficult to fully exert the required characteristics in the layer. The present invention has been made based on such findings.

In other words, according to the present invention, there is provided a prepreg comprising a fiber base material, a first resin layer which is coated on one surface side of the fiber base material and which is composed of a first resin composition, and another side surface on which the fiber base material is coated a second resin layer composed of a second resin composition different from the first resin composition, and the second resin layer is present at least 90% of the thickness of the fiber base material from the other surface of the fiber base material. Immersed in the above fibrous substrate.

In such a prepreg, a second resin layer impregnated into the fibrous base material over at least 90% of the thickness of the fibrous base material from the other side of the fibrous base material is formed. Therefore, it is not necessary to impregnate the first resin layer in a large amount in the fibrous base material. Therefore, the first resin composition constituting the first resin layer is not limited to those having good impregnation with the fiber base material, and the selection range of the first resin composition is widened. Also, a first resin layer having desired characteristics can be produced Prepreg.

Further, a method of producing the above prepreg can also be provided. In other words, according to the present invention, there is provided a method for producing a prepreg comprising the steps of: pressing a first resin sheet against one surface of a fiber base material and providing a first resin layer composed of a first resin composition; a step of forming a second resin layer composed of a second resin composition different from the first resin composition on the other surface side of the fiber base material, and forming at least the fiber in the step of forming the second resin layer The other surface of the substrate is impregnated with the second resin layer in the fiber base material over 90% of the thickness of the fiber base material.

According to this production method, the second resin layer impregnated into the fiber base material at least 90% of the thickness of the fiber base material from the other side of the fiber base material is formed. Therefore, it is not necessary to impregnate the first resin sheet in a large amount in the fibrous base material. Therefore, the first resin composition constituting the first resin layer is not limited to those having good impregnation with the fiber base material, and the selection range of the first resin composition is expanded to form the first resin layer having desired characteristics. Furthermore, a substrate having a hardened body of the prepreg and a circuit layer in which the circuit layer is embedded in the second resin layer of the cured body of the prepreg, and the prepreg is provided A metal layer is provided on the first resin layer of the cured body. Further, a semiconductor device including the substrate and a semiconductor element mounted on the substrate may be provided.

According to the present invention, it is possible to provide a prepreg and a method for producing a prepreg which have different resin layers and can more reliably exhibit desired characteristics of the respective resin layers.

1, 1a~1f‧‧‧ prepreg

2‧‧‧Fiber substrate

3‧‧‧1st resin layer

3'‧‧‧1st resin sheet

4‧‧‧2nd resin layer

4'‧‧‧2nd resin sheet

5, 7‧‧‧ sheets

6, 6a‧‧‧ manufacturing equipment

8‧‧‧Resin film

10‧‧‧Substrate

11‧‧‧Layer

12‧‧‧metal layer

13‧‧‧ Inner layer circuit board

31‧‧‧1st impregnation

32, 42‧‧‧ Coverage Department

43‧‧‧2nd Impregnation Department

51‧‧‧Support

64‧‧‧Drying device

65‧‧‧Fitting device

100‧‧‧Semiconductor device

200‧‧‧Multilayer substrate

201a~201e‧‧‧ Circuit Department

202, 203‧‧‧ conductor

300‧‧‧ solder pad

400‧‧‧Wiring Department

500‧‧‧Semiconductor components

501‧‧‧Bumps

611‧‧‧ nozzle

621~629, 651, 652‧‧ ‧ rolls

F‧‧‧ interface

T, ta, ta ₁ , tb, tb ₁ ‧ ‧ thickness

Θ‧‧‧ angle

The above and other objects, features, and advantages of the invention will be apparent from the description and appended claims appended claims

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a cross-sectional view showing a prepreg according to an embodiment of the present invention.

Figure 2 is a cross-sectional view of the prepreg.

Fig. 3 is a schematic view showing a manufacturing apparatus of a prepreg.

Fig. 4 is a schematic view showing a manufacturing apparatus of a prepreg.

Fig. 5 is a cross-sectional view showing a substrate.

Fig. 6 is a cross-sectional view showing a semiconductor device.

7(a) to 7(c) are schematic views showing a method of measuring the resin flow rate.

Fig. 8 is a view showing a cross section of the prepreg of Example 1.

Fig. 9 is a view showing a cross section of the prepreg of Example 5.

Fig. 10 is a view showing a cross section of a prepreg of Example 6.

Fig. 11 is a view showing a cross section of a prepreg of Comparative Example 1.

Fig. 12 is a view showing a cross section of a prepreg of Comparative Example 2.

Hereinafter, embodiments of the present invention will be described based on the drawings. In the drawings, the same components are denoted by the same reference numerals, and the detailed description thereof may be omitted as appropriate. First, an outline of a prepreg according to the present embodiment and a method of manufacturing the same will be described with reference to Figs. 1 and 3 .

Figure 1 is a cross-sectional view showing a prepreg. The prepreg 1 of the present embodiment includes the fiber base material 2, the first resin layer 3 including the first resin composition on one side of the coated fiber base material 2, and the other surface side of the coated fiber base material 2, and The second resin layer 4 composed of the second resin composition having the first resin composition is different, and the first resin layer 3 is in contact with the second resin layer 4 to form the interface F. Further, the second resin layer 4 is impregnated into the fibrous base material 2 from at least 90% of the thickness of the fibrous base material 2 from the other surface of the fibrous base material 2. Here, the first resin composition is different from the second resin composition, and may constitute each resin. The composition of the composition may be different or may be different in composition ratio.

Moreover, the method for producing a prepreg according to the present embodiment includes the step of pressing the first resin sheet 3' against one surface of the fiber base material 2 and providing the first resin layer 3 including the first resin composition. In the step, the second resin layer 4 formed of the second resin composition different from the first resin composition is formed on the other surface side of the fiber base material 2. In the above step of forming the second resin layer 4, the second resin layer 4 impregnated into the fiber base material 2 from at least 90% of the thickness of the fibrous base material 2 from the other surface of the fibrous base material 2 is formed.

Next, a method of manufacturing a prepreg and a prepreg will be described in detail with reference to Figs. 1 to 4 .

<Prepreg>

Hereinafter, the prepreg 1 of the present embodiment will be described in detail. In the following description, the upper side of FIG. 1 (the same applies to the following drawings) is referred to as "upper", and the lower side is described as "lower".

The prepreg 1 shown in Fig. 1 has a flat fibrous base material 2, a first resin layer 3 on one side (lower surface) side of the fibrous base material 2, and another surface (upper surface) on the fibrous base material 2. The second resin layer 4 on the side. This prepreg 1 is used for a printed wiring board (circuit board).

The fibrous base material 2 has a function of improving the mechanical strength of the prepreg 1. Examples of the fiber base material 2 include glass fiber substrates such as glass woven fabrics and glass nonwoven fabrics, and phthalamides such as polyamide resin fibers, aromatic polyamide resin fibers, or wholly aromatic polyamide resin fibers. Polyurethane resin fiber such as fiber, polyester resin fiber such as polyester resin fiber, aromatic polyester resin fiber or wholly aromatic polyester resin fiber, polyparaphenylene benzobis a synthetic fiber substrate of woven or non-woven fabric as a main component of any one or more of azole, polyimine resin fiber, fluororesin fiber, etc.; kraft paper, cotton velvet paper, mixed paper of cotton velvet and kraft pulp, etc. A fibrous base material such as an organic fiber base material such as a paper fiber base material as a main component. Among these, any one or more kinds of fibrous base materials can be used.

Among these, the fibrous base material 2 is preferably a glass fiber base material. By using the glass fiber substrate, the mechanical strength of the prepreg 1 can be further improved. Further, there is also an effect that the thermal expansion coefficient of the prepreg 1 can be reduced.

Examples of the glass constituting the glass fiber substrate include E glass, C glass, A glass, S glass, D glass, NE glass, T glass, Q glass, H glass, UT glass, L glass, and the like. Any one or more of these may be used. Among these, the glass is preferably S glass, T glass, UT glass, or Q glass. Thereby, the thermal expansion coefficient of the glass fiber base material can be made relatively small, and therefore, the prepreg 1 can be set to have a thermal expansion coefficient as small as possible.

The average thickness T of the fiber base material 2 is not particularly limited, but is preferably 150 μm or less, more preferably 100 μm or less, still more preferably about 10 μm to 50 μm. By using the fiber base material 2 having such a thickness, the mechanical strength of the prepreg 1 can be ensured, and the thickness thereof can be reduced. Further, the workability in the case where the prepreg 1 is subjected to drilling or the like can be improved. Further, the average thickness T of the fibrous base material 2 can be measured from the thickness of one side of the fibrous base material 2 to the other surface by the intersection of the longitudinal and transverse threads of the fibrous base material 2, and the average is calculated. Obtained by value.

The first resin layer 3 is provided on one surface side of the fiber base material 2, and the second resin layer 4 is provided on the other surface side. Further, the first resin layer 3 is composed of a first resin composition, and the second resin layer 4 is composed of a second resin composition different from the first resin composition. The first resin layer 3 covers one surface of the fiber base material 2, and the second resin layer 4 covers the other surface of the fiber base material 2. The first resin layer 3 is formed by directly forming a wiring portion (metal layer) on the upper portion thereof. Floor. On the other hand, the second resin layer 4 is buried in the layer of the circuit layer. Further, in the present invention, the prepreg does not include a film which is peeled off when the substrate is manufactured. Further, the first resin layer 3 and the second resin layer 4 are in a state of semi-hardening (B-stage).

In the present embodiment, in order to form a metal wiring portion (circuit portion) on the first resin layer 3, the first resin composition is set to have a composition excellent in adhesion to metal. More specifically, the first resin layer 3 of the prepreg 1 is superposed on the copper foil, and the 90° peel strength A after heat treatment in the atmosphere for 1 hour under a load of 2 MPa and a temperature of 220 ° C is higher than that. The second resin layer 4 of the prepreg 1 was superposed on the copper foil, and the 90° peel strength B after heat treatment in the air for 1 hour under a load of 2 MPa and a temperature of 220 ° C. The peel strength can be measured in the 90 degree direction in accordance with the 90 degree peeling method of JIS C 6481. Specifically, the 90-degree peel strength at the time of peeling off the resin layer was measured at a speed of 50 mm per minute at 25 ° C using a 90-degree peeling tester. More specifically, the peel strength A is preferably 0.5 kN/m or more. More preferably, it is 0.6 kN/m or more, and particularly preferably 0.8 kN/m or more. By setting it as 0.5 kN/m or more, the adhesiveness with a wiring part can be improved. Further, the upper limit of the peel strength A is not particularly limited, but is preferably 2 kN/m or less. On the other hand, the peel strength B is preferably 0.4 N/m or more. Among them, it is preferably 0.5 N/m or more. By setting it as 0.4 N/m or more, the adhesion to the inner layer wiring part can be improved. On the other hand, the upper limit of the peel strength B is not particularly limited, but is preferably 1 kN/m or less. The peel strength A-peeling strength B is preferably 0.1 kN/m or more, and more preferably 1.6 kN/m or less.

Moreover, in order to reliably embed the wiring portion (circuit) of the other prepreg 1, the second resin composition is preferably set such that the lowest melt viscosity of the second resin layer 4 is lower than that of the first resin layer 3. The lowest melt viscosity is explained below. Further, in the present embodiment, in order to impregnate the second resin layer 4 with the inside of the fiber base material 2, the second resin composition constituting the second resin layer 4 preferably has a good impregnation property with respect to the fiber base material 2. . turn off Each resin composition is described in detail below.

As shown in Fig. 1, in the present embodiment, one portion of the second resin layer 4 is impregnated throughout the thickness direction of the fiber base material 2. More specifically, the second resin layer 4 includes an impregnation portion 43 impregnated inside the fiber base material 2 and a coating portion 42 covering the surface (the other surface) of the fiber base material 2. Here, the impregnation portion 43 of the second resin layer 4 is impregnated into the fiber base material 2 at least at a position from the surface covered with the coating portion 42 of the fiber base material 2 to 90% of the thickness of the fiber base material 2. In the present embodiment, the impregnation portion 43 is impregnated into the fiber base material 2 over the entire thickness of the fiber base material 2. The impregnation portion 43 is in contact with the first resin layer 3, but the impregnation portion 43 and the first resin layer 3 are not mixed with each other, and an interface F at the boundary is formed between the impregnation portion 43 and the first resin layer 3. Thereby, the functions of the respective resin layers 3 and 4 can be reliably exhibited.

Further, the interface F between the impregnation portion 43 and the first resin layer 3 is located on the outer side of the fiber base material 2. More specifically, the first resin layer 3 is in contact with one surface of the fiber base material 2, but is not impregnated into the fiber base material 2. Further, the impregnation portion 43 abuts against the first resin layer 3 to form an interface F. Further, in the present embodiment, the first resin layer 3 is directly in contact with one surface of the fiber base material 2, but the present invention is not limited thereto, and the impregnation portion 43 may be impregnated from one surface of the fiber base material 2, On the other hand, the first resin layer 3 is not directly in contact with one surface of the fiber base material 2. In the present embodiment, the average thickness T of the fibrous base material 2 is equal to the thickness ta of the second resin layer 4. As described above, the interface between the second resin layer 4 and the first resin layer 3 is present outside the fiber base material 2, and the intersection of the interface with the fiber base material 2 disappears. Here, in the case where a large number of intersections of the interface and the fibrous base material 2 exist, there is a fear that the following phenomenon occurs. It is considered that a hole such as a through hole is formed in the prepreg, and when a metal layer is formed inside the hole, metal ions enter from the intersection of the interface between the fiber substrate 2 and the resin layer, and further migrate along the interface. Generally, the adhesion between the fibrous base material 2 and the resin layer is poor, so that the metal is considered to be away from the metal. The precursor easily enters from the intersection of the interface between the fibrous substrate 2 and the resin layer. By metal ion migration, the insulation reliability between holes is reduced. On the other hand, by the disappearance of the intersection of the interface and the fibrous base material 2, the metal ions entering between the fibrous base material 2 and the second resin layer 4 can be prevented from migrating to the interface. Thereby, the insulation reliability between the holes can be improved. Further, in the present embodiment, since the first resin layer 3 is not impregnated into the fibrous base material 2, it is not necessary to consider the impregnation property with respect to the fibrous base material 2. Further, as the first resin layer 3, it is only necessary to select a good adhesion to the metal, so that the design range of the first resin layer 3 can be expanded. In addition, the cross section perpendicular to the thickness direction of the prepreg 1 was observed by a scanning electron microscope (SEM, Scanning Electron Microscope), and the interface between the first resin layer 3 and the second resin layer 4 was confirmed. Moreover, in the cross section orthogonal to the thickness direction of the prepreg 1, it is preferable to form the interface between the first resin layer 3 and the second resin layer 4 over the entire width direction of the prepreg 1. By having such a structure, the functions of the respective resin layers 3 and 4 can be reliably exhibited. Further, the first resin layer 3 is not impregnated into the fibrous base material 2, and no other fibrous base material is present in the first resin layer 3.

Further, in the present embodiment, the impregnation portion 43 is impregnated into the fiber base material 2 over the entire thickness of the fiber base material 2, but the present invention is not limited thereto, and the first resin layer 3 may be impregnated into the fiber base material 2 in. As shown in FIG. 2, the impregnation portion 43 of the second resin layer 4 is impregnated into the fiber from the surface (the other surface) covered by the covering portion 42 of the fiber base material 2 to 90% or more of the thickness of the fiber base material 2. In the substrate 2. That is, the thickness ta ₁ of the impregnation portion 43 is 90% or more of the thickness T of the fiber base material 2. Further, the impregnation portion 31 of the first resin layer 3 is impregnated into the fibrous base material 2. The impregnation portion 31 is impregnated into the fibrous base material 2 at a position from the surface (one surface) of the fibrous base material 2 covered by the covering portion 32 to 10% or less of the thickness of the fibrous base material 2. The thickness tb ₁ of the impregnation portion 31 is 10% or less of the thickness T of the fiber base material 2. The impregnation portion 31 is impregnated with a region not impregnated by the impregnation portion 43. Further, the first impregnation portion 31 as a part of the first resin layer 3 and the second impregnation portion 43 as a part of the second resin layer 4 are located in the fiber base material 2. In the fiber base material 2, the first impregnation portion 31 (the lower surface of the first resin layer 3) is in contact with the second impregnation portion 43 (the upper surface of the second resin layer 4). Further, an interface F is formed at the boundary between the first impregnation portion 31 and the impregnation portion 43. The other aspects are the same as in Fig. 1.

In this manner, the impregnation portion 43 is impregnated into the fiber base material 2 from the surface covered by the covering portion 42 of the fiber base material 2 to 90% or more of the thickness of the fiber base material 2, whereby the second resin layer 4 can be reduced. The interface with the first resin layer 3 and the intersection with the fibrous base material 2. Thereby, metal ions entering between the fiber base material 2 and the second resin layer 4 can be prevented from migrating at the above interface. Thereby, the insulation reliability between the holes can be improved. Further, the impregnation portion 31 is impregnated into the fibrous base material 2 at a position from the surface of the fibrous base material 2 covered by the covering portion 32 to 10% or less of the thickness of the fibrous base material 2, but the impregnation amount of the impregnation portion 31 is only In a small amount, it is almost unnecessary to consider the impregnation property of the impregnation portion 31 with respect to the fibrous base material 2. Therefore, as the first resin layer 3, it is only necessary to select a good adhesion to the metal, so that the design range of the first resin layer 3 can be expanded. Moreover, as shown in FIG. 2, the first resin layer 3 and the second resin layer 4 are brought into contact with each other inside the fiber base material 2, whereby peeling between the first resin layer 3 and the second resin layer 4 can be prevented. In other words, the first resin composition constituting the first resin layer 3 and the second resin constituting the second resin layer 4 are impregnated with the first resin layer 3 and the second resin layer 4 by the woven fiber base material 2. The composition is caught on the fibrous base material 2 to prevent peeling between the first resin layer 3 and the second resin layer 4.

In addition, the case where the second resin layer 4 is impregnated into the fiber base material 2 at a position 90% of the thickness of the fiber base material 2 can be confirmed as follows. The average value T of the thickness of the fiber base material 2 was calculated, and 90% of the thickness (value C) was calculated. Further, the average value D (measured at 10 locations) from the other surface of the fibrous base material 2 to the interface F between the first resin layer 3 and the second resin layer 4 may exceed the numerical value C.

Further, in order to form the interface F between the first resin layer 3 and the second resin layer 4, the details will be described below. For example, the lowest melt viscosity η1 of the first resin layer 3 and the lowest melt viscosity of the second resin layer 4 may be used. The ratio η2 (η1/η2) is 1.1 times or more, or any layer may be supplied to the fiber base material 2 in a sheet form at the time of production, and the other layer may be supplied to the fiber base material 2 in the form of a varnish.

Moreover, the average thickness of the covering portion 42 of the second resin layer 4 is t _a [μm], and the average thickness of the portion of the first resin layer 3 covering the one surface of the fiber base material 2 is t _b [μm] Preferably, t _{a is} greater than t _b . The wiring portion can be formed on the surface of the prepreg 1 (on the resin layer 3) with high workability. On the other hand, since the second resin layer 4 can have high flexibility and a sufficient thickness, when the wiring portion or other fiber substrate of the other prepreg 1 is embedded in the second resin layer 4, it can be confirmed. This embedding is performed to improve the embedding property of the wiring portion or other fibrous substrate of the other prepreg 1.

Specifically, the average thickness t _{b is} preferably from 0.1 to 15 μm, more preferably from 1 to 10 μm. On the other hand, the average thickness t _{a is} preferably from 4 to 50 μm, more preferably from 8 to 40 μm.

Further, the average thickness t _a and the average thickness t _b can be obtained by measuring 10 points at arbitrary intervals and calculating the average value.

Further, the lowest melt viscosity (η1) of the first resin layer 3 and the lowest melt viscosity (η2) of the second resin layer 4 in the range of 50 to 150 ° C when the temperature is raised at a temperature increase rate of 3 ° C/min at 25 ° C The ratio η1/η2 is preferably 1.1 or more and 100 or less. Further, the lowest melt viscosity (η1) of the first resin layer 3 is higher than the lowest melt viscosity (η2) of the second resin layer 4. Thereby, the impregnation property of the second resin layer 4 with respect to the fiber base material 2 can be improved, and the first resin layer 3 can be prevented from being impregnated into the fiber base material 2 in a large amount. In addition, when the lowest melt viscosity ratio η1/η2 is 1.1 or more, the first resin layer 3 and the second resin layer 4 cannot be mixed, and an interface is formed between the first resin layer 3 and the second resin layer 4. Also, by setting the lowest melt viscosity ratio η1/η2 100 or less, especially 80 or less, has the effect of improving the adhesiveness of an interface. The measurement conditions of the lowest melt viscosity are as follows. The measurement was carried out under the conditions of a measurement frequency of 62.83 rad/sec, a temperature increase rate of 3 ° C/min, and 50 to 150 ° C using a dynamic viscoelasticity measuring apparatus. Here, specifically, the lowest melt viscosity η1 of the first resin layer 3 is preferably 1000 Pa. s above, and 25000 Pa. s below. On the other hand, the lowest melt viscosity (η2) of the second resin layer 4 is preferably 50 Pa. Above s, and 10000 Pa. s below, of which, is 5000 Pa. s below, and further 3000 Pa. s below. It is preferable that the lowest melt viscosity (η1) of the first resin layer 3 is 1.1 times or more the lowest melt viscosity (η2) of the second resin layer 4, and the lowest melt viscosity of each resin layer is set to the above range. The prepreg in which the second resin layer 4 is impregnated into the fiber base material 2 at least 90% of the thickness of the fiber base material 2 can be easily produced.

Further, it is preferable that the prepreg 1 of the present embodiment also satisfies the following characteristics. According to the IPC-TM-650 method 2.3.17, the resin flow rate measured under conditions of 171±3° C. and 1380±70 kPa for 5 minutes is 15% by weight or more and 50% by weight or less. The weight of the resin layer exposed from the outer edge of the fibrous base material 2 in a plan view when heated and pressurized at 120 ° C and 2.5 MPa in a state in which the pair of rubber sheets are sandwiched between the pair of rubber sheets (the total weight of the first resin layer 3 and the second resin layer 4) is 5% or less based on the total weight of the entire first resin layer 3 and the entire second resin layer 4, and the rubber sheet satisfies the following (i) to (() Iii).

(i) The rubber hardness measured according to JIS K 6253 A is 60°

(ii) thickness is 3 mm

(iii) Material is 矽

By using the IPC-TM-650 method 2.3.17, the resin flow rate measured under conditions of 171±3° C. and 1380±70 kPa for 5 minutes is 15% by weight or more, and the circuit can be obtained. A prepreg with excellent embedding properties. Again, by above the resin flow rate When the thickness is 50% by weight or less, when the prepreg is laminated, the outflow of the resin layer from the prepreg can be suppressed. Therefore, when the core layer (see FIG. 5) such as the inner layer circuit board 13 is laminated, the circuit of the inner layer circuit board 13 is excellent in embedding property, and when the laminate is pressed, the resin layer can be prevented from flowing out of the prepreg. The prepreg is used for layering. Further, when the prepreg 1 is sandwiched between the pair of rubber sheets, the resin is exposed from the outer edge of the fiber substrate 2 in plan view when heated and pressurized at 120 ° C and 2.5 MPa. The weight of the layer is set to 5% by weight or less, whereby the thickness uniformity of the obtained laminate can be improved. Therefore, it is possible to achieve excellent embedding property of the circuit of the inner layer circuit board 13 when laminated on the inner layer circuit board 13, and to prevent the resin layer from flowing out of the prepreg during lamination pressing, and to improve the thickness uniformity of the prepreg. . Further, when the prepreg 1 is sandwiched between the pair of rubber sheets, the resin exposed from the outer edge of the fiber substrate 2 in plan view is heated and pressurized at 120 ° C and 2.5 MPa. The lower limit of the weight of the layer is not particularly limited and is, for example, 0.1% by weight.

Here, in order to obtain the first resin layer 3 and the second resin layer 4 having the above characteristics, the first resin composition and the second resin composition are preferably configured as follows.

The first resin composition contains, for example, a thermosetting resin, and optionally contains at least one of a curing aid (for example, a curing agent, a curing accelerator, and the like) and an inorganic filler.

In order to improve the adhesion to the metal constituting the wiring portion, a method of using a thermosetting resin having excellent adhesion to metal, and a curing aid for improving adhesion to a metal (for example, a curing agent or a hardening promotion) may be mentioned. A method of using a solvent, etc., a method of using an acid-soluble material as an inorganic filler, a method of using an inorganic filler and an organic filler, and a method of using a specific thermoplastic resin.

In the thermosetting resin, for example, urea (urea) resin, melamine resin, bismaleimide resin, polyurethane resin, and benzoic acid can be suitably used. An epoxy resin such as a ring resin, a cyanate resin, a bisphenol S type epoxy resin, a bisphenol F type epoxy resin, and a copolymerized epoxy resin of bisphenol S and bisphenol F. Any one or more of these may be used. Further, among these, a thermosetting resin is preferably a cyanate resin (prepolymer containing a cyanate resin).

The cyanate resin can be obtained, for example, by reacting a halogenated cyanide compound with a phenol, and if necessary, prepolymerizing by heating or the like.

Specific examples of the cyanate resin include a novolak type cyanate resin, a bisphenol A type cyanate resin, a bisphenol E type cyanate resin, and a tetramethylbisphenol F type cyanate resin. A bisphenol type cyanate resin or the like. Any one or more of these may be used. Among these, the cyanate resin is preferably a novolac type cyanate resin.

When a novolac type cyanate resin is used, the crosslinking density of the first resin layer 3 after curing is increased after the substrate 10 (see FIG. 5) described below is produced. Therefore, the cured first resin layer 3 can be obtained. Heat resistance and flame retardancy of the obtained substrate.

Here, it can be considered that the improvement in heat resistance is formed by a novolac type cyanate resin after the hardening reaction. Caused by the ring. Further, it is considered that the improvement of the flame retardancy is caused by the fact that the novolac type cyanate resin has a high proportion of the benzene ring in its structure, and the benzene ring is easily carbonized (graphitized), and will be the first after hardening. A carbonized portion is produced in the resin layer 3.

Further, when a novolac type cyanate resin is used, even when the prepreg 1 is made thinner (for example, having a thickness of 35 μm or less), the prepreg 1 can be provided with excellent rigidity. Moreover, since the cured product is excellent in rigidity at the time of heating, the obtained substrate 10 is also excellent in reliability when the semiconductor element 500 (see FIG. 6) is mounted. Specifically, a novolac type cyanate resin represented by the formula (I) can be used.

[Chemical 1]

In the novolac type cyanate resin represented by the formula (I), the average repeating unit number "n" is not particularly limited, but is preferably 1 to 10, more preferably 2 to 7. When the average repeating unit number "n" is less than the above lower limit value, the novolac type cyanate resin is easily crystallized, and thus the solubility in a general-purpose solvent is lowered. Therefore, it is difficult to use the first resin composition depending on the content of the novolac type cyanate resin or the like. Further, there is a phenomenon in which the viscous property is generated when the prepreg 1 is produced, the first prepreg 1 is adhered to each other, or the first resin composition of the prepreg 1 is transferred to the other prepreg 1 (transfer) The case of India). On the other hand, when the average number of repeating units "n" exceeds the above upper limit, the viscosity of the first resin composition becomes too high, and the efficiency of the prepreg 1 is formed (formability of the first resin layer 3). Reduce the situation.

Further, when a curing agent or a curing accelerator for improving adhesion to a metal is used in combination, in addition to the above thermosetting resin, for example, a phenol novolak resin, a cresol novolak resin, or a bisphenol A phenol aldehyde may be used. A phenolic resin such as a novolak type phenol resin such as a varnish resin, a resole phenolic resin, a modified phenol resin such as tung oil, linseed oil or walnut oil, and the like, and a phenol resin such as a phenolic phenol resin , bisphenol type epoxy resin such as bisphenol A epoxy resin, bisphenol F epoxy resin, novolak type epoxy resin such as novolak epoxy resin, cresol novolac epoxy resin, biphenyl type epoxy resin, etc. Other thermosetting resins such as epoxy resin, unsaturated polyester resin, diallyl phthalate resin, and polyoxyn resin. Any one or more of these may be used.

The content of the thermosetting resin is not particularly limited, but is preferably 5 to 50% by weight, and more preferably 10 to 40% by weight based on the entire first resin composition. When the content of the thermosetting resin is less than the above-mentioned lower limit, the viscosity of the varnish of the first resin composition may be too low depending on the type of the thermosetting resin, and it may be difficult to form the prepreg 1 . On the other hand, when the content of the thermosetting resin is more than the above-mentioned upper limit, the amount of the other components is too small, and the mechanical strength of the prepreg 1 may be lowered depending on the type of the thermosetting resin or the like. In the present specification, the case of the resin composition means that the solvent is removed, and the components other than the solvent are made into 100 parts by weight, and the content of each component is specified.

Examples of the above-mentioned curing aid (for example, a curing agent, a curing accelerator, and the like) include tertiary amines such as triethylamine, tributylamine, and diazepam [2,2,2]octane, and 2-B. 4-ethylimidazole, 2-benzene-4-methylimidazole, 2-phenyl-4-methyl-5-hydroxymyimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 2,4-diamine- 6-[2'-methimidazole-(1')]-B-symmetric three 2,4-Diamine-6-(2'-undecylimidazole)-B-symmetric three 2,4-Diamine-6-[2'-ethyl-4-methylimidazolium-(1')]-B-symmetric three An imidazole compound such as 1-benzyl-2-benzimidazole. Any one or more of these may be used.

Among these, the curing aid is preferably one or more selected from the group consisting of an aliphatic compound having an aliphatic hydrocarbon group, an aromatic hydrocarbon group, a hydroxyalkyl group, and a cyanoalkyl group selected from the group consisting of an aliphatic hydrocarbon group, an aromatic hydrocarbon group, and a hydroxyalkyl group. A functional group, more preferably 2-benzene-4,5-dihydroxymethane.

Further, in the first resin composition, for example, an organic metal such as zinc naphthenate, cobalt naphthenate, tin octylate, cobalt octoate, acetoacetate cobalt (II), or triethyl sulfonium cobalt (III) may be used in combination. A salt, a phenol compound such as phenol, bisphenol A or indophenol, an organic acid such as acetic acid, benzoic acid, salicylic acid or p-toluenesulfonic acid. Any one or more of these may be used.

When the curing aid is used, the content thereof is preferably from 0.01 to 3% by weight, more preferably from 0.1 to 1% by weight, based on the total of the first resin composition.

Further, the first resin composition preferably contains an inorganic filler. With this, Even if the prepreg 1 is made thinner (for example, having a thickness of 35 μm or less), the prepreg 1 having excellent mechanical strength can be obtained. Further, the low thermal expansion property of the prepreg 1 can be improved.

Examples of the inorganic filler include talc, alumina, glass, cerium oxide such as molten cerium oxide, mica, aluminum hydroxide, magnesium hydroxide, and the like. Any one or more of these may be used. Further, depending on the purpose of use of the inorganic filler, a crushed or spherical shape can be appropriately selected. Among these, the inorganic filler is preferably cerium oxide, and more preferably molten cerium oxide (especially spherical molten cerium oxide) from the viewpoint of excellent low thermal expansion property.

The average particle diameter of the inorganic filler is preferably from 0.01 to 5.0 μm, more preferably from 0.2 to 2.0 μm. Further, the average particle diameter is d ₅₀ and can be measured by the following method. The inorganic filler was dispersed in water by ultrasonic waves, and the particle size distribution of the inorganic filler was measured by a dynamic light scattering type particle size distribution measuring apparatus (HL-550, manufactured by HORIBA, Inc.), and the radius was set as the average particle diameter. .

In particular, as the inorganic filler, spherical molten cerium oxide having an average particle diameter of 5.0 μm or less is preferable.

Further, in order to improve the adhesion between the first resin layer 3 and the wiring portion, an inorganic filler which is soluble in acid may be used as the inorganic filler. When the wiring portion (conductor layer) is formed on the first resin layer 3 by the plating method, the adhesion of the wiring portion to the first resin layer 3 (plating adhesion) can be improved. Examples of the inorganic filler which is soluble in the acid include metal oxides such as calcium carbonate, zinc oxide, and iron oxide.

Further, in order to improve the adhesion between the first resin layer 3 and the wiring portion, an inorganic filler and an organic filler may be used in combination. Examples of the organic filler include a resin-based filler such as a liquid crystal polymer or a polyimide.

In the case of using an inorganic filler, the content thereof is not particularly limited. It is preferably 20 to 70% by weight, and more preferably 30 to 60% by weight based on the entire first resin composition.

When a cyanate resin (particularly a novolak type cyanate resin) is used as the thermosetting resin, it is preferred to use an epoxy resin in combination (substantially free of halogen atoms). Examples of the epoxy resin include a phenol novolak type epoxy resin, a bisphenol type epoxy resin, a naphthalene type epoxy resin, and an aryl alkylene type epoxy resin. Any one or more of these may be used.

Among these, the epoxy resin is preferably one or more of a naphthalene type epoxy resin and an aryl alkylene type epoxy resin. By using these epoxy resins, the moisture-absorbing solder heat resistance (weld heat resistance after moisture absorption) and the flame retardancy of the first resin layer 3 after curing can be improved.

The naphthalene type epoxy resin refers to a group having a naphthalene skeleton in a repeating unit. The naphthalene type epoxy resin is preferably a naphthol type epoxy resin, a naphthalene diphenol type epoxy resin, a bifunctional to tetrafunctional epoxy type naphthalene resin, or a naphthyl ether type epoxy resin. Any one or more of these may be used. Thereby, heat resistance and low thermal expansion property can be further improved. Further, since the naphthalene ring has a higher π-π stacking effect than the benzene ring, it is particularly excellent in low thermal expansion property and low heat shrinkage property. Further, since the rigidity of the multi-ring structure is high and the glass transition temperature is particularly high, the change in heat shrinkage before and after the reflow is small. The naphthol type epoxy resin can be represented, for example, by the following formula (VII-1), and as the naphthalenediol type epoxy resin, it can be represented by the following formula (VII-2), and is a bifunctional to tetrafunctional epoxy. The naphthalene resin can be represented by the following formula (VII-3) (VII-4) (VII-5), and the stannaphthyl ether type epoxy resin can be represented, for example, by the following formula (VII-6). Any one or more of them may be used. Among them, a naphthyl ether type epoxy resin is preferred from the viewpoint of low water absorption and low thermal expansion. The stretched naphthyl ether type epoxy resin refers to an epoxy resin having a structure in which a naphthalene skeleton is bonded to another aryl group via an oxygen atom.

[Chemical 2]

(n represents an average of 1 or more and 6 or less, and R represents a glycidyl group or a hydrocarbon group having 1 or more carbon atoms and 10 or less; wherein any one of R is a glycidyl group)

(wherein R ¹ represents a hydrogen atom or a methyl group, and R ² each independently represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an aralkyl group, or a naphthyl group, or a naphthyl group having a glycidyl ether group; , o and m are integers from 0 to 2, respectively, and either o or m is 1 or more)

As the stearyl ether type epoxy resin, for example, those shown by the following formulas (6) and (7) can also be used.

The arylalkylene-type epoxy resin is an epoxy resin having one or more arylalkylene groups in the repeating unit, and examples thereof include a phthalic epoxy resin and a biphenyl dimethylene epoxy resin. Any one or more of these may be used. Further, among these, the arylalkylene type epoxy resin is preferably a biphenyl dimethylene type epoxy resin.

Specifically, a biphenyl dimethylene type epoxy resin represented by the formula (II) can be used.

The average repeating unit number "n" of the biphenyl dimethylene type epoxy resin represented by the formula (II) is not particularly limited, but is preferably 1 to 10, more preferably 2 to 5. If the average repeat When the number of bits "n" is less than the above lower limit, the biphenyl dimethylene type epoxy resin is easily crystallized, so that the solubility in a general-purpose solvent is lowered. Therefore, there is a case where the varnish of the first resin composition becomes difficult to handle. On the other hand, when the average repeating unit number "n" exceeds the above upper limit value, the viscosity of the varnish of the first resin composition rises depending on the solvent to be used. In this case, the first resin composition cannot be sufficiently impregnated into the fiber base material 2, and as a result, molding failure of the prepreg 1 or deterioration of mechanical strength may occur.

The lower limit of the content of the epoxy resin is not particularly limited, but is preferably 1% by weight or more, and particularly preferably 2% by weight or more based on the entire resin composition. If the content is too small, the reactivity of the cyanate resin is lowered, or the moisture resistance of the obtained product is lowered. The upper limit of the content of the epoxy resin is not particularly limited, but is preferably 40% by weight or less. If the content is too large, heat resistance may be lowered.

The lower limit of the weight average molecular weight (Mw) of the epoxy resin is not particularly limited, but is preferably Mw 500 or more, and particularly preferably Mw 800 or more. If the Mw is too small, there is a case where the resin layer is sticky. The upper limit of Mw is not particularly limited, and is preferably Mw 20,000 or less, and particularly preferably Mw 15,000 or less. When the Mw is too large, when the insulating resin layer is formed, the impregnation property to the fibrous base material is lowered, and a uniform product cannot be obtained. The Mw of the epoxy resin can be measured, for example, by gel permeation chromatography (GPC, Gel Permeation Chromatography).

Further, a component (including a resin or the like) which improves adhesion to a metal may be added to the first resin composition. The thermoplastic resin of the phenoxy resin, the polyvinyl acetal resin, and the polyamidamide resin is preferably contained in the above-mentioned one or more. Among these resins, from the viewpoint of adhesion to metal, it is preferred to contain a phenoxy resin. Further, the first resin composition preferably contains a coupling agent.

As the phenoxy resin, for example, a phenoxy group having a bisphenol skeleton can be cited. A resin, a phenoxy resin having a naphthalene skeleton, a phenoxy resin having a biphenyl skeleton, or the like. Further, a phenoxy resin having a structure of a plurality of such skeletons may also be used. As the phenoxy resin, any one or more of them may be used.

Among these, the phenoxy resin is preferably a phenoxy resin having a biphenyl skeleton and a bisphenol S skeleton. Thereby, the glass transition temperature of the phenoxy resin can be increased by the rigidity of the biphenyl skeleton, and the adhesion of the phenoxy resin to the metal can be improved by the presence of the bisphenol S skeleton. As a result, the heat resistance of the first resin layer 3 can be improved, and the adhesion between the wiring portion (metal) and the first resin layer 3 can be improved when the multilayer substrate is produced.

Further, the phenoxy resin is preferably a phenoxy resin having a bisphenol A skeleton and a bisphenol F skeleton. Thereby, when the multilayer substrate is manufactured, the adhesion of the wiring portion to the first resin layer 3 can be further improved.

The molecular weight of the phenoxy resin is not particularly limited, and the weight average molecular weight is preferably 5,000 to 70,000, more preferably 10,000 to 60,000.

In the case of using a phenoxy resin, the content thereof is not particularly limited, but is preferably 1 to 40% by weight, and more preferably 5 to 30% by weight based on the entire first resin composition.

The polyvinyl acetal resin is a resin obtained by acetalizing polyvinyl alcohol with a carbonyl compound such as formaldehyde or acetaldehyde. Examples of the polyvinyl acetal resin include polyethylene formaldehyde and polyvinyl butyral. Any one or more of these may be used. The degree of acetalization of the polyvinyl acetal resin is preferably 40% or more from the viewpoint of water absorbability, and is preferably 80% or less from the viewpoint of compatibility. As the polyamine-based resin, an aromatic polyamine can be cited from the viewpoint of heat resistance. Moreover, the weight average molecular weight of the polyamine-based resin is preferably 15,000 or more from the viewpoint of adhesion to the conductor layer. Examples of the polyamine-based resin include aromatic polyamine-poly(butadiene-acrylonitrile) blocks containing a phenolic hydroxyl group. Polymer (for example, trade name KAYAFLEX BPAM-155 (Japanese chemical, terminal is amidino)).

The thermoplastic resin as described above is preferably from 1 to 40% by weight, more preferably from 10 to 30% by weight, based on the total of the first resin composition.

The coupling agent is preferably one or more selected from the group consisting of an epoxy cyclane coupling agent, a titanate coupling agent, an amino decane coupling agent, and an eucalyptus type coupling agent.

In the case of using a coupling agent, the content thereof is not particularly limited, and is preferably 0.05 to 3 parts by weight, more preferably 0.1 to 2 parts by weight, per 100 parts by weight of the inorganic filler.

Further, the first resin composition may contain an additive such as an antifoaming agent, a leveling agent, a pigment, or an antioxidant, in addition to the components described above.

The second resin composition is set to have a composition different from that of the first resin composition, and specifically, the embedding property of the second resin layer 4 is set to be superior to that of the first resin layer 3, and the composition of the above physical properties is satisfied.

The constituents of the second resin composition may be the same as those exemplified in the first resin composition, but the type and content of the resin or the filler, the molecular weight of the resin (the average number of repeating units), and the like are different. As a result, the second resin layer 4 has characteristics different from those of the first resin layer 3. The second resin composition contains, for example, the above-described thermoplastic resin, thermosetting resin, inorganic filler, curing accelerator, and the like. The second resin composition contains, for example, the above-described epoxy resin, cyanate resin, and inorganic filler. The epoxy resin is preferably an epoxy resin having a naphthalene skeleton and having a structure in which a naphthalene skeleton is bonded to another aryl group via an oxygen atom. Here, the inorganic filler contained in the second resin layer 4 is preferably a spherical molten cerium oxide having an average particle diameter of 5.0 μm or less, more preferably an average particle diameter of 0.01 to 2.0 μm, particularly an average particle diameter. It is a spherical molten cerium oxide of 10 to 50 nm. By using such cerium oxide (nano-cerium oxide) having an average particle diameter of 50 nm or less, the heat resistance of the prepreg 1 can be improved. It is known that in the case of using cerium oxide having an average particle diameter of 50 nm or less, cerium oxide is dispersed in the strands of the fibrous substrate 2, and the resin component is also infiltrated into the strands. Thereby, it is possible to suppress the formation of voids in the strands of the fiber base material 2 of the prepreg 1, and it is possible to improve the heat resistance of the prepreg 1. Further, the second resin composition preferably contains cerium oxide having an average particle diameter of 0.5 to 5 μm in addition to the above-mentioned cerium oxide having a particle diameter of 50 nm or less. On the other hand, in order to form fine concavities and convexities and to improve adhesion to the conductor circuit layer, it is preferable to use cerium oxide having an average particle diameter of 0.5 μm to 50 nm.

Further, the content of the thermoplastic resin in the second resin layer 4 is lower than the content of the thermoplastic resin in the first resin layer 3. Thereby, the embedding property of the circuit of the second resin layer 4 can be improved. On the other hand, the adhesion of the conductor circuit in the first resin layer 3 can be made good. Specifically, the content of the thermoplastic resin in the second resin layer 4 is 10% by weight or less, and preferably 5% by weight or less, of the second resin composition constituting the second resin layer 4. However, the second resin layer 4 may not contain a thermoplastic resin.

<Method of Manufacturing Prepreg>

As the prepreg 1 described above, the manufacturing apparatus shown in Fig. 3 can be used as follows. As shown in FIG. 3, the manufacturing apparatus 6 has the rollers 621-628, the nozzle (the die coater as a discharge means) 611, and the drying apparatus 64.

The roller 621 feeds the first resin sheet 3' which becomes the first resin layer 3, and the first resin sheet 3' to which the support 51 is attached is wound around the roller 621 (in FIG. 3, support is included) The sheet of the body 51 and the first resin sheet 3' is referred to as a sheet 5). The roller 621 is configured to rotate by a motor (drive source) (not shown), and when the roller 621 rotates, the sheet 5 including the first resin sheet 3' is fed from the roller 621. Furthermore, as the support 51, for example, A metal foil (metal layer), a resin film, etc. are mentioned, among these, a metal foil is preferable. The metal foil is processed, for example, into a portion such as a wiring portion (circuit). Examples of the metal material constituting the metal foil include copper or a copper alloy, aluminum or aluminum alloy, iron or iron alloy, and stainless steel. Further, among the metal materials constituting the metal foil, among them, conductivity is excellent, and it is easy to form a circuit by etching, and in terms of inexpensiveness, copper or a copper-based alloy is preferable. Further, the lowest melt viscosity of the first resin sheet 3' at 50 to 150 ° C is 1000 Pa. s above, and 25000 Pa. s below. By this, the lowest melt viscosity at 50 to 150 ° C is set to 1000 Pa. s or more, the first resin sheet 3' is less likely to be impregnated into the fibrous base material 2. Moreover, it becomes difficult to mix with the 2nd resin layer 4. By setting the lowest melt viscosity at 50~150 °C to 25000 Pa. Below s, the adhesion to the fiber base material 2 can be ensured. Furthermore, the measurement method is as described above.

Further, the roller 623 is a means for feeding the fiber base material 2, and the fiber base material 2 is wound around the roll 623. The roller 623 is configured to rotate by a motor (not shown), and when the roller 623 rotates, the fiber base material 2 is continuously fed from the roller 623.

Further, the roller 622 is a means for restricting the moving direction of the sheet 5, and is provided in the subsequent stage of the roller 621.

Further, the roller 624 is a means for restricting the moving direction of the fiber base material 2, and is provided in the subsequent stage of the roller 622.

Further, the roller 625 is a means for bonding the first resin sheet 3' to the fiber base material 2, and is provided in the subsequent stage of the rolls 622 and 624. The first resin sheet 3' is conveyed so as to be in contact with the outer peripheral surface of the outer peripheral surface of the roller 625. At this time, the first resin sheet 3' is in contact with the upper surface via the support 51 and the 1/4 of the circumference of the roller 625. Further, the fiber base material 2 is also conveyed so as to be in contact with the outer peripheral surface of the outer surface of the roller 625. The fiber base material 2 is a portion where the roller 625 is indirectly contacted with the first resin sheet 3', and passes through the first resin sheet 3' and the roller. 625 contact. The fiber base material 2 is conveyed so as to be in contact with the outer peripheral surface of the outer surface of the roll 625. However, the contact area between the fibrous base material 2 and the roller 625 is smaller than the contact area between the first resin sheet 3' and the roller 625. Further, the fiber base material 2 and the first resin sheet 3' are stretched in the conveying direction, and tension is applied thereto. Thereby, the first resin sheet 3' and the fiber base material 2 can be press-bonded by the outer peripheral surface of the roll 625. By pressing the fiber base material 2 and the first resin sheet 3' by the roller 625 as described above, it is possible to prevent the first resin sheet 3' from being excessively impregnated into the fiber base material 2. Further, the roller 626 and the roller 627 restrict the movement direction of the sheet 5 including the first resin sheet 3', the fiber base material 2, and the second resin layer 4 on the fiber base material 2, and are sequentially disposed on The next step of the roller 625.

Further, the roller 628 is a means for winding the prepreg 1. The roller 628 is configured to rotate by a motor (not shown), and when the roller 628 is rotated, the prepreg 1 is wound onto the roller 628.

In addition, the nozzle 611 is a means for discharging (supplying) a liquid (varnish-like) second resin composition at a normal temperature (25 ° C) on the surface of the fiber base material 2 opposite to the first resin layer 3 (for example, Mold coating machine). In addition, the liquid state is not limited to a liquid, and is a concept including a fluidity.

The drying device 64 is disposed between the nozzle 611 and the roller 626. In the present embodiment, the drying device 64 can be dried while the object is horizontally conveyed. Thereby, the tension applied to the fibrous base material 2 can be made relatively small, and internal distortion can be prevented or suppressed.

(Step 1)

As shown in FIG. 3, the roll 621 of the manufacturing apparatus 6 is rotated, the sheet 5 containing the first resin sheet 3' is continuously fed from the roll 621, and the roll 623 is rotated and sent out from the roll 623 (continuously The fiber substrate 2 is supplied, and the roller 628 is rotated to wind the prepreg 1 to the roller 628.

The first resin sheet 3' is in a B-stage state. Then, the first resin sheet 3' and the fiber base material 2 are press-bonded to the roll 625.

At this time, the angle (bonding angle) θ of the angle formed by the first resin sheet 3' and the fiber base material 2 is preferably an acute angle. Thereby, deformation of the fiber base material 2 can be prevented or suppressed.

Further, the tension on the side of the fiber base material 2 is preferably smaller than the tension on the side of the first resin sheet 3'. Specifically, the tension on the side of the fiber base material 2 is preferably 30 N or less, more preferably about 15 to 25 N. Thereby, the dimensional change or internal deformation of the fibrous base material 2 can be prevented or suppressed. Further, as shown in FIG. 2, when the first resin layer 3 is impregnated into the fiber base material 2, the tension of the first resin sheet 3' is adjusted, and the first resin layer can be impregnated into the fiber base material 2. in.

(Step 2)

Then, the varnish containing the second resin composition is discharged from the nozzle 611, and the varnish is supplied to the surface of the fiber base material 2 opposite to the first resin sheet 3'.

(Step 3 (drying step))

Then, the first resin sheet 3' and the varnish containing the second resin composition are heated and dried by the drying device 64. Thereby, the prepreg 1 is obtained. The prepreg 1 is taken up onto a roller 628. Further, as shown in FIG. 2, when the first resin layer is impregnated into the fibrous base material 2, the first resin layer may be impregnated into the fibrous base material 2 in the drying step.

The drying conditions are not particularly limited, and may be appropriately set depending on the composition of the first resin composition and the second resin composition (especially the composition of the second resin composition) or each condition, and it is preferable to use the second resin. The volatile component in the composition is set to be 1.5 wt% or less with respect to the resin, and more preferably set to be about 0.8 to 1.0 wt%. Specifically, the drying temperature is preferably from 100 to 150 ° C, more preferably from about 100 to 130 ° C. Further, the drying time is preferably about 2 to 10 minutes, more preferably about 2 to 5 minutes.

In the present embodiment, when the first resin sheet 3' is press-bonded to the fiber base material 2 and the second resin layer 4 is formed, the varnish containing the second resin composition is supplied to the fiber base material 2. Thereby, the interface between the first resin layer 3 and the second resin layer 4 can be reliably formed. Further, in the present embodiment, since the varnish containing the second resin composition is supplied to the fiber base material 2, the second resin composition can be easily impregnated into the fiber base material 2. On the other hand, since the first resin layer 3 is formed into a sheet shape in advance and is supplied to the fiber base material 2 in a sheet form, it is less likely to be impregnated into the fiber base material 2 than the second resin layer 4 . Thereby, the prepreg 1 in which the second resin layer 4 is impregnated into the fiber base material 2 at least 90% of the thickness of the fiber base material 2 can be easily produced.

Further, in the present embodiment, the prepreg 1 is manufactured using the manufacturing apparatus 6 shown in Fig. 3. However, the prepreg 1 can be manufactured using the manufacturing apparatus 6a shown in Fig. 4. This manufacturing apparatus 6a does not have the nozzle 611 of the manufacturing apparatus 6, and has the bonding apparatus 65 and the roller 629. The other aspects are the same as the manufacturing apparatus 6.

The bonding device 65 is disposed between the roller 627 and the roller 628. The bonding apparatus 65 has a pair of rollers 651 and 652 disposed opposite to each other, and heating units (not shown) of the heating rollers 651 and 652, and the object is sandwiched between the roller 651 and the roller 652, and the object is added. It is composed of pressure and heating.

The roller 629 is disposed in front of the bonding device 65. The roller 629 is a means for feeding out an object, and the following sheet 7 is wound around the roller 629. The roller 629 is configured to rotate by a motor (not shown), and when the roller 629 rotates, the sheet 7 is continuously fed from the roller 629.

In the drying device 64, the fiber base material 2 and the first resin sheet 3' are heated to melt the first resin sheet 3'. Further, as shown in FIG. 1, when the first resin layer 3 is not impregnated into the fibrous base material 2, the drying device 64 may not be used. Manufacturing device The roller 629 of 6a is rotated, and the sheet 7 is fed from the roller 629. As shown in FIG. 4, the sheet 7 has a resin film 8 and a second resin sheet 4' provided on one surface of the resin film 8 and containing a solid or semi-solid second resin composition. The second resin sheet 4' is in a B-stage state. The lowest melt viscosity (η2) of the second resin sheet 4' at 50 to 150 ° C is lower than the lowest melt viscosity (η1) of the first resin sheet 3' at 50 to 150 °C. Thereby, the second resin sheet 4' can be easily impregnated into the fibrous base material 2, and the second resin layer 4 can be impregnated to 90% or more of the thickness of the fibrous base material 2. In addition, when the lowest melt viscosity ratio η1/η2 is 1.1 or more, the first resin layer 3 and the second resin layer 4 cannot be mixed, and an interface is formed between the first resin layer 3 and the second resin layer 4. Further, by setting the lowest melt viscosity ratio η1/η2 to 100 or less, particularly 80 or less, there is an effect of improving the adhesion of the interface. Specifically, the lowest melt viscosity (η1) of the first resin sheet 3' is preferably 1000 Pa. s above, and 25000 Pa. s below. On the other hand, the lowest melt viscosity (η2) of the second resin sheet 4' is preferably 50 Pa. Above s, and 10000 Pa. s below, of which, is 5000 Pa. s below, and further 3000 Pa. The following is ideal. Furthermore, the measurement method is as described above.

As the resin film 8, the same as those described for the resin film as the support 51 can be used.

In this step, the sheet 7 and the sheet 5 which is a laminate of the fibrous base material 2 and the support 51 pass between the roll 651 of the bonding device 65 and the roll 652. At this time, the sheet 7 and the fibrous substrate 2 The laminate with the support 51 is pressurized by the bonding device 65 and heated. Thereby, the sheet 7 can be press-bonded to the surface of the fiber base material 2 opposite to the first resin layer 3 via the second resin sheet 4', and the prepreg 1 as a laminated sheet can be obtained. The prepreg 1 is taken up onto a roller 628.

The conditions at the time of the press-bonding are not particularly limited, and may be appropriately set depending on the composition or conditions of the second resin composition of the second resin layer 4, and the pressure is preferably about 0.1 to 1.0 MPa/cm ² , more preferably It is about 0.3 to 0.5 MPa/cm ² . Further, the heating temperature is preferably from 100 to 130 °C. The first resin sheet 3' and the second resin sheet 4' are melted by the heating at the time of press bonding, but the lowest melt viscosity of the second resin layer 4 is lower than that of the first resin layer 3, whereby the second resin layer 4 can be used. The resin layer 4 is impregnated into the fibrous base material 2. In addition, as described above, the lowest melt viscosity ratio η1/η2 of the first resin layer 3 and the second resin layer 4 can be formed between the first resin layer 3 and the second resin layer 4 by setting the ratio η1/η2 to 1.1 or more. interface.

<Substrate>

Next, the substrate of the present invention will be described with reference to Fig. 5 . The substrate 10 shown in FIG. 5 has a laminate 11 and a metal layer 12 provided on both surfaces of the laminate 11.

The laminated body 11 includes two prepregs 1 disposed inside the second resin layer 4 and an inner layer circuit board 13 sandwiched between the second resin layers 4 . The resin layers 3, 4 of the prepreg 1 are completely cured on the substrate.

The circuit layer (not shown) formed on the surface of the inner layer circuit board 13 is surely embedded in the second resin layer 4.

The metal layer 12 is formed as a portion of the wiring portion, and is formed by, for example, bonding a metal foil such as a copper foil or an aluminum foil to the laminated body 11 and plating copper or aluminum on the surface of the laminated body 11. Further, the support 51 may be the metal layer 12.

The peeling strength of the metal layer 12 and the first resin layer 3 is preferably 0.5 kN/m or more, and more preferably 0.6 kN/m or more. Thereby, the metal layer 12 is processed into a wiring portion, and the connection reliability in the obtained semiconductor device 100 (see FIG. 6) can be further improved.

In the substrate 10, two prepregs 1 in which the metal layer 12 is formed on the first resin layer 3 are prepared, and in the state in which the inner layer circuit board 13 is sandwiched by the prepreg 1, for example, A method of laminating a vacuum press, a normal pressure laminating machine, and a laminating machine heated and pressurized under vacuum. Vacuum pressing can be carried by clamping between the plates and using the usual heat It is implemented by a press or the like. For example, a vacuum press manufactured by a machine manufacturer, a vacuum press manufactured by Beichuan Seiki Co., Ltd., a vacuum press manufactured by Mikado Technos Co., Ltd., and the like can be cited. In addition, as a laminating machine, a vacuum applicator manufactured by Nichigo-Morton Co., Ltd., a vacuum pressurizing laminator manufactured by a machine manufacturer, and a vacuum roll drier manufactured by Hitachi Techno-Engineering Co., Ltd. can be used. It is manufactured by a commercially available vacuum laminator or a belt press, such as a Dry Coater.

Further, the substrate 10 of the present invention can omit the inner layer circuit board 13 and include a laminate in which the two prepregs 1 are directly joined to the second resin layer 4, and the metal layer 12 can be omitted.

<semiconductor device>

Next, a semiconductor device of the present invention will be described with reference to FIG. In FIG. 6, the fiber base material 2 and the inner layer circuit board 13 are omitted, and the first resin layer 3 and the second resin layer 4 are integrally shown.

The semiconductor device 100 shown in FIG. 6 has a multilayer substrate 200, a pad portion 300 provided on the upper surface of the multilayer substrate 200, a wiring portion 400 provided on the lower surface of the multilayer substrate 200, and the pad portion 300 and the bumps. The semiconductor element 500 mounted on the multilayer substrate 200 is connected by 501. Further, a wiring portion, a pad portion, a solder ball, or the like may be provided on the lower surface of the multilayer substrate 200.

The multilayer substrate 200 includes a substrate 10 provided as a core substrate, three prepregs 1a, 1b, and 1c provided on the upper side of the substrate 10, and three prepregs 1d, 1e, and 1f provided on the lower side of the substrate 10. . The prepregs 1a to 1f are the same as the prepreg 1. In the prepreg 1a to 1c, the second resin layer 4 is provided on the substrate 10 side, that is, the prepreg is placed so as to be the second resin layer 4, the fiber base material 2, and the first resin layer 3 from the substrate 10 side. Body 1. On the other hand, the prepregs 1d to 1f are formed by providing the second resin layer 4 on the substrate 10 side. In other words, the prepreg 1 is placed in such a manner that the second resin layer 4, the fiber base material 2, and the first resin layer 3 are sequentially formed. In the multilayer substrate 200, the resin layers 3, 4 of the prepreg 1 are completely cured.

Further, the multilayer substrate 200 has a circuit portion 201a provided between the prepreg 1a and the prepreg 1b, a circuit portion 201b provided between the prepreg 1b and the prepreg 1c, and a prepreg 1d and a pre-preg. The circuit portion 201d between the dip bodies 1e and the circuit portion 201e provided between the prepreg 1e and the prepreg 1f. Each of the circuit portions 201a to 201e is buried by the second resin layer 4.

Further, the multilayer substrate 200 has holes penetrating through the respective prepregs 1a to 1f, and a conductor portion 202 electrically connecting the adjacent circuit portions or the circuit portions and the pad portions is formed in the holes.

Each of the metal layers 12 of the substrate 10 is processed into a predetermined pattern, and the processed metal layers 12 are electrically connected to each other by a conductor portion 203 provided through the substrate 10.

Further, in the semiconductor device 100 (multilayer substrate 200), four or more prepregs 1 may be provided on one side of the substrate 10. Further, the semiconductor device 100 may include a prepreg other than the prepreg 1 of the present invention.

Further, the present invention is not limited to the above-described embodiments, and modifications, improvements, etc. within the scope of the object of the invention can be included in the present invention. The embodiment of the present invention has been described with respect to the prepreg, the substrate, and the semiconductor device of the present invention. However, the present invention is not limited thereto, and the components constituting the prepreg, the substrate, and the semiconductor device may be the same. Any constitutive of the function is exchanged. Further, any constituent may be added.

<attachment>

(Note 1)

A prepreg comprising a fiber base material, a first resin layer including a first resin composition covering one surface side of the fiber base material, and another surface side covering the fiber base material, and including the first resin The second resin layer composed of the second resin composition having a different composition, and the first resin layer is in contact with the second resin layer to form an interface.

(Note 2)

The prepreg according to the first aspect, wherein the first resin layer is a layer provided with a metal layer on an upper surface thereof, and the second resin layer is a layer for embedding a circuit.

(Note 3)

The prepreg according to the first or second aspect, wherein the second resin layer is impregnated into the fibrous base material at least in a region from the other surface of the fibrous base material to a center of a thickness of the fibrous base material.

(Note 4)

The prepreg according to the third aspect, wherein the second resin layer is impregnated into the fibrous base material at least at a position from the other surface of the fibrous base material to 90% of the thickness of the fibrous base material.

(Note 5)

The prepreg according to the fourth aspect, wherein the second resin layer is impregnated into the fiber base material, and an interface between the first resin layer and the second resin layer is located outside the fiber base material.

(Note 6)

The prepreg according to any one of the preceding claims, wherein the content of the thermoplastic resin in the first resin layer is higher than the content of the thermoplastic resin in the second resin layer.

(Note 7)

The prepreg according to any one of the preceding claims, wherein the first resin layer of the prepreg is overlapped with the copper foil, and heat-treated at a load of 2 MPa and a temperature of 220 ° C for 1 hour. The subsequent 90° peel strength A is higher than the 90° peel strength B after the second resin layer of the prepreg is overlapped with the copper foil and heat-treated at a load of 2 MPa and a temperature of 220° C. for 1 hour.

(Note 8)

The prepreg according to any one of the items 1 to 7, wherein the resin is measured by heating and pressurizing for 5 minutes at 171 ± 3 ° C and 1380 ± 70 kPa according to the IPC-TM-650 method 2.3.17. When the flow rate is 15% by weight or more and 50% by weight or less, when the prepreg is sandwiched between the pair of rubber sheets, the glass is heated and pressurized at 120 ° C and 2.5 MPa, and is viewed from above. The total weight of the first resin layer and the second resin layer exposed from the outer edge of the fiber base material is 5% or less based on the total weight of the entire first resin layer and the entire second resin layer, and the rubber sheet Meet the following (i) to (iii),

(i) The rubber hardness measured according to JIS K 6253 A is 60°

(ii) thickness is 3 mm

(iii) The material is 矽.

(Note 9)

The prepreg according to any one of the preceding claims, wherein the first resin layer contains a thermoplastic resin, and the thermoplastic resin contains any one of a phenoxy resin, a polyvinyl alcohol resin, and a polyamine resin. More than one species.

(Note 10)

The prepreg according to any one of the items 1 to 9, wherein the second resin layer contains an epoxy resin, a cyanate resin, and an inorganic filler.

(Note 11)

The prepreg according to any one of the preceding claims, wherein the first resin layer and the second resin layer have a structure having a naphthalene skeleton and having a naphthalene skeleton bonded to another aryl group via an oxygen atom. Epoxy resin.

(Note 12)

The prepreg according to any one of the preceding claims, wherein the prepreg system is produced by: forming a first resin sheet as a first resin layer and the fiber substrate in the first resin layer; One of the surfaces of the fiber substrate is impregnated with the second resin sheet or the liquid resin composition containing the second resin composition.

(Note 13)

The prepreg according to any one of the items 1 to 12, wherein the lowest melt viscosity of the first resin layer in the range of 50 ° C or more and 150 ° C or less when the temperature is raised at a temperature increase rate of 3 ° C / min at 25 ° C The ratio η1/η2 of the lowest melt viscosity η2 of η1 and the second resin layer is 1.1 times or more and 100 times or less.

(Note 14)

The prepreg according to any one of the items 1 to 13, wherein the second resin layer contains cerium oxide having a particle diameter of 50 nm or less.

(Note 15)

The prepreg according to supplementary note 14, wherein the fibrous base material is a glass cloth, and the above-mentioned cerium oxide is present in a strand of the glass cloth.

(Note 16)

A substrate having a prepreg according to any one of the above-mentioned items 1 to 15, comprising a circuit layer, wherein said second resin layer of said prepreg is embedded in said circuit layer, and said first prepreg A metal layer is provided on the resin layer.

(Note 17)

A semiconductor device comprising a substrate as shown in Attachment 16 and a semiconductor element mounted on the substrate.

(Note 18)

A method for producing a prepreg comprising the steps of: press-fitting a first resin sheet against one surface of a fiber base material, and providing a first resin layer formed of the first resin composition; and a step of forming a second resin layer formed of the second resin composition different from the first resin composition, and forming at least the other side of the fiber substrate in the step of forming the second resin layer The second resin layer is impregnated into the fiber base material over 90% of the thickness of the fiber base material.

(Note 19)

The method for producing a prepreg according to the eighth aspect, wherein the first resin sheet has a minimum melt viscosity of 1000 Pa at 50 to 150 ° C. s above, and 25000 Pa. s below.

(Note 20)

The method for producing a prepreg according to the above-mentioned item 18 or 19, wherein in the step of forming the second resin layer, a liquid second resin composition is supplied to the other surface side of the fiber base material.

(Note 21)

The method of producing a prepreg according to the above-mentioned item 18 or 19, wherein in the step of forming the second resin layer, the second resin sheet serving as the second resin layer is supplied to the other surface side of the fiber base material, and the heating is performed. The second resin sheet is impregnated into the fiber base material, and the lowest melting of the first resin sheet in the range of 50° C. or higher and 150° C. or lower at 25° C. at a temperature increase rate of 3° C./min. The ratio η1/η2 of the viscosity η1 to the lowest melt viscosity η2 of the second resin sheet is 1.1 times or more and 100 times or less.

(Note 22)

The method for producing a prepreg according to any one of the items 18 to 21, wherein, in the step of pressing the first resin sheet against one surface of the fiber base material, the first resin sheet is directly used Or indirectly contacting the surface of the laminating roll along the outer circumference of the laminating roll The first resin sheet is continuously conveyed, and the fiber is continuously conveyed toward the stacking roll so as to be in contact with the stacking roll via the first resin sheet at a portion where the stacking roll is in contact with the first resin sheet. Substrate.

(Note 23)

The method for producing a prepreg according to any one of the preceding claims, wherein the first resin sheet is wound into a roll, and the first resin sheet is fed from the roll to form the first resin sheet. In the above step of press-bonding to one surface of the fiber base material, the fed first resin sheet is pressed against one surface of the fiber base material.

(Note 24)

The method for producing a prepreg according to any one of the items 18 to 23, wherein the first resin sheet is formed on a support, and the first resin sheet is pressed against one side of the fiber base material. In the above step, the first resin sheet on the support is pressed against one surface of the fiber base material.

Example

Next, an embodiment of the present invention will be described.

(Example 1) (first resin composition)

The first resin composition of A-1 of Table 1 was produced. First, 12.2 parts by weight of a naphthalene type epoxy resin (manufactured by Nippon Kayaku Co., Ltd., trade name NC-7300), a naphthalene type epoxy resin (manufactured by DIC Corporation, trade name: HP4700), 5 parts by weight, and a phenolic novolak type cyanic acid. 17.2 parts by weight of an ester resin (manufactured by Lonza Co., Ltd., trade name: PT-30), 15 parts by weight of a biphenyl type phenoxy resin (manufactured by Mitsubishi Chemical Corporation, trade name YX-6954BH30) (in terms of solid content), and as a hardener 1-benzyl-2-methimazole (manufactured by Shikoku Chemical Co., Ltd., Curezol 1B2PZ) 0.4 parts by weight was dissolved in methyl ethyl ketone. Further, 50 parts by weight of a spherical cerium oxide (manufactured by Electric Chemical Industry Co., Ltd., trade name: SFP-20M, average particle diameter: 0.3 μm), and an epoxy decane coupling agent (manufactured by Shin-Etsu Chemical Co., Ltd.) are added as an inorganic filler. The name KBM-403E) was 0.2 parts by weight and stirred for 60 minutes using a high speed mixer. Thereby, a varnish having a resin composition of 70% by weight was produced. Next, a polyethylene terephthalate film (manufactured by Unitika Co., Ltd., thickness: 38 μm, width: 560 mm) was used as a carrier film, and the above varnish was applied by a notch wheel coating device, and dried at 170 ° C by a drying device. In a minute, a first resin sheet having a thickness of 5 μm and a width of 540 mm (a layer serving as a first resin layer) was formed. Further, the average particle diameter of the cerium oxide is obtained by dispersing cerium oxide in water by ultrasonic waves, and the cerium oxide is measured on a volume basis by a dynamic light scattering type particle size distribution measuring apparatus (manufactured by HORIBA, LB-550). The particle size distribution is defined by the number of radii. Specifically, the average particle diameter is defined by the volume cumulative particle diameter d ₅₀ . The following examples and comparative examples are also the same.

(second resin composition)

A second resin composition having the composition shown in B-1 of Table 2 was produced. 9 parts by weight of a naphthalene ether type epoxy resin (manufactured by DIC Corporation, trade name: HP-6000), 6 parts by weight of a biphenyl aralkyl type phenol resin (manufactured by Nippon Kayaku Co., Ltd., trade name NC-3000), and a phenol system 15.5 parts by weight of a novolac type cyanate resin (manufactured by Lonza Co., Ltd., trade name PT-30) was dissolved in methyl ethyl ketone. Further, 66 parts by weight of spherical cerium oxide (SO-31R, average particle diameter: 1.0 μm, manufactured by Admatech Co., Ltd.) and spherical cerium oxide (manufactured by Admatechs Co., Ltd., trade name Admanano, average particle diameter 50) were added as an inorganic filler. Nb) 0.5 parts by weight of an epoxy decane coupling agent (manufactured by Shin-Etsu Chemical Co., Ltd., trade name KBM-403E), 0.5 parts by weight, and stirred for 60 minutes using a high speed mixer. Thereby, a varnish having a resin composition of 70% by weight was produced.

(Pre-impregnation production)

The prepreg is manufactured by the manufacturing apparatus 6 shown in FIG. The roller 621 of the manufacturing apparatus 6 is rotated, and the first resin sheet 3' with the carrier film attached thereto is sent from the roller 621. Further, the roller 623 was rotated, and the fiber base material 2 (WEX-1017, basis weight 12 g/m ² , 13 μm) was fed from the roll 623. The first resin sheet 3' and the fiber base material 2 are press-bonded to the roll 625. At this time, the temperature of the roller 625 was 95 °C. Thereafter, the varnish containing the second resin composition is discharged from the nozzle 611, and the varnish is supplied to the surface of the fiber base material 2 opposite to the first resin layer 3. Then, the first resin sheet 3' and the varnish containing the second resin composition were dried by heating at 120 ° C for 2 minutes by a drying device 64. Thereby, the prepreg 1 (thickness 35 μm) was obtained.

(Example 2)

(first resin composition)

The first resin composition of A-2 of Table 1 was produced. First, 12.2 parts by weight of a naphthalene-modified cresol novolak epoxy resin (manufactured by DIC Corporation, trade name: HP-5000), and a naphthalene type epoxy resin (manufactured by DIC Corporation, trade name: HP4700), 5 parts by weight, a phenolic novolac 17.2 parts by weight of a cyanate resin (manufactured by Lonza Co., Ltd., trade name: PT-30), and 15 parts by weight of a biphenyl type phenoxy resin (manufactured by Mitsubishi Chemical Corporation, trade name: YX-6954BH30) (in terms of solid content), and as The 1-benzyl-2-methylimidazole (manufactured by Shikoku Chemical Co., Ltd., Curezol 1B2PZ) of the hardener was dissolved in methyl ethyl ketone. Furthermore, 50 parts by weight of a spherical molten cerium oxide (manufactured by Electric Chemical Industry Co., Ltd., trade name: SFP-20M, average particle diameter: 0.3 μm) as an inorganic filler, and an epoxy decane coupling agent (manufactured by Shin-Etsu Chemical Co., Ltd., The name KBM-403E) was 0.2 parts by weight and stirred for 60 minutes using a high speed mixer. Thereby, a varnish having a resin composition of 70% by weight was produced. Then, a polyethylene terephthalate film (manufactured by Unitika Co., Ltd., thickness: 38 μm, width: 560 mm) was used as a carrier film, and the above varnish was applied by a notch wheel coating device, and dried at 170 ° C by a drying device. In a minute, a first resin sheet having a thickness of 5 μm and a width of 540 mm (a layer serving as a first resin layer) was formed.

(second resin composition)

The second resin composition is prepared in the same manner as in the first embodiment.

(manufacturing of prepreg)

A prepreg was produced in the same manner as in Example 1 by using the above-mentioned resin layer containing a polyethylene terephthalate film and a varnish containing the above second resin composition.

(Example 3)

(first resin composition)

The first resin composition of A-3 of Table 1 was produced. First, a naphthalene-modified cresol novolac epoxy resin (manufactured by DIC Corporation, trade name: HP-5000), 16.2 parts by weight, a naphthalene-type epoxy resin (manufactured by DIC Corporation, trade name: HP4700), 9 parts by weight, a phenolic novolac Type cyanate resin (manufactured by Lonza Co., Ltd., trade name PT-30) 24.2 parts by weight, rubber modified phenolic hydroxyl group-containing polyamine resin (manufactured by Nippon Kayaku Co., Ltd., trade name BPAM-155, Mw = 15,000 or more 15 parts by weight and 0.4 parts by weight of 1-benzyl-2-methylimidazole (Curezol 1B2PZ, manufactured by Shikoku Chemicals Co., Ltd.) as a curing agent were dissolved in methyl ethyl ketone. Further, 35 parts by weight of a spherical molten cerium oxide (manufactured by Electric Chemical Industry Co., Ltd., trade name: SFP-20M, average particle diameter: 0.3 μm) as an inorganic filler, and an epoxy decane coupling agent (manufactured by Shin-Etsu Chemical Co., Ltd., The name KBM-403E) was 0.2 parts by weight and stirred for 60 minutes using a high speed mixer. Thereby, a varnish having a resin composition of 70% by weight was produced. Next, a polyethylene terephthalate film (manufactured by Unitika Co., Ltd., thickness: 38 μm, width: 560 mm) was used as a carrier film, and the above varnish was applied by a notch wheel coating device, and dried at 170 ° C by a drying device. In a minute, a first resin sheet having a thickness of 5 μm and a width of 540 mm (a layer serving as a first resin layer) was formed.

(second resin composition)

The second resin composition is prepared in the same manner as in the first embodiment.

(manufacturing of prepreg)

Using the above resin layer with a polyethylene terephthalate film, including the above second A prepreg of the resin composition was produced in the same manner as in Example 1.

(Example 4)

(first resin composition)

A first resin composition similar to that of Example 3 was produced, and a resin layer having a polyethylene terephthalate film as in Example 1 was used.

(second resin composition)

A second resin composition having the composition shown in Table 2-2 of Table 2 was produced. 9 parts by weight of a dicyclopentadiene type epoxy resin (manufactured by DIC Corporation, trade name: HP-7200L) and 6 parts by weight of a biphenyl aralkyl type phenol resin (manufactured by Nippon Kayaku Co., Ltd., trade name: GPH-65). A phenolic novolac type cyanate resin (manufactured by Lonza Co., trade name: PT-30) was dissolved in methyl ethyl ketone in an amount of 15.5 parts by weight. Further, 66 parts by weight of spherical cerium oxide (SO-31R, average particle diameter: 1.0 μm, manufactured by Admatech Co., Ltd.) and spherical molten cerium oxide (manufactured by Admatechs, trade name Admanano, average particle diameter) were added as an inorganic filler. 50 parts by weight of 0.5 parts by weight and 0.5 part by weight of an epoxy decane coupling agent (manufactured by Shin-Etsu Chemical Co., Ltd., trade name KBM-403E) was stirred for 60 minutes using a high speed mixer. Thereby, a varnish having a resin composition of 70% by weight was produced.

(manufacturing of prepreg)

A prepreg was produced in the same manner as in Example 1 by using the above-mentioned resin layer containing a polyethylene terephthalate film and the varnish of the above second resin composition.

(Example 5)

(first resin composition)

A first resin composition similar to that of Example 3 was produced, and a resin layer having a polyethylene terephthalate film as in Example 1 was used.

(second resin composition)

A second resin composition having the composition shown in B-3 of Table 2 was produced. 10 parts by weight of a naphthalene ether type epoxy resin (manufactured by DIC Corporation, trade name: HP-6000), and a biphenyl aralkyl type phenol resin (manufactured by Nippon Kayaku Co., Ltd., trade name: GPH-65), 8 parts by weight, phenol system 14.5 parts by weight of a novolac type cyanate resin (manufactured by Lonza Co., Ltd., trade name: PT-30), and 2 parts by weight of a biphenyl type phenoxy resin (manufactured by Mitsubishi Chemical Corporation, trade name: YX-6954BH30) (solid content conversion) Dissolved in methyl ethyl ketone. Further, 65 parts by weight of spherical molten cerium oxide (SO-31R, average particle diameter: 1.0 μm, manufactured by Admatech Co., Ltd.) and an epoxy decane coupling agent (manufactured by Shin-Etsu Chemical Co., Ltd., trade name KBM-) were added as an inorganic filler. 403E) 0.5 parts by weight, stirred using a high speed mixer for 60 minutes. Thereby, a varnish having a resin composition of 70% by weight was produced.

(manufacturing of prepreg)

A prepreg was produced in the same manner as in Example 1 by using the above-mentioned resin layer containing a polyethylene terephthalate film and the varnish of the above second resin composition.

(Example 6)

(first resin composition)

A first resin composition similar to that of Example 3 was produced, and a resin layer having a polyethylene terephthalate film as in Example 1 was used.

(second resin composition)

A second resin composition having the composition shown in B-4 of Table 2 was produced. 10 parts by weight of a dicyclopentadiene type epoxy resin (manufactured by DIC Corporation, trade name: HP-7200L), and a biphenyl aralkyl type phenol resin (manufactured by Nippon Kayaku Co., Ltd., trade name: GPH-65) And a phenolic novolac type cyanate resin (manufactured by Lonza Co., Ltd., trade name: PT-30), 14.5 parts by weight, and a biphenyl type phenoxy resin (manufactured by Mitsubishi Chemical Corporation, trade name: YX-6954BH30), 2 parts by weight ( The solid fraction conversion is dissolved in methyl ethyl ketone. Further, adding a ball as an inorganic filler 65 parts by weight of molten cerium oxide (manufactured by Admatech Co., Ltd., SO-31R, average particle diameter: 1.0 μm), and 0.5 parts by weight of an epoxy decane coupling agent (manufactured by Shin-Etsu Chemical Co., Ltd., trade name: KBM-403E), using a high-speed mixer Stir for 60 minutes. Thereby, a varnish having a resin composition of 70% by weight was produced.

(manufacturing of prepreg)

A prepreg was produced in the same manner as in Example 1 by using the above-mentioned resin layer containing a polyethylene terephthalate film and the varnish of the above second resin composition.

(Comparative Example 1)

A prepreg was produced using the varnish of the first resin composition of the composition of A-1 produced in Example 1 and the varnish of the second resin composition of the composition represented by B-1. The varnish of the first resin composition was applied to one surface of the fiber substrate by a die coater, and the varnish of the second resin composition was applied to the other surface, and dried by heating at 180 ° C for 2 minutes. Thereby, a prepreg (thickness 35 μm) was obtained.

(Comparative Example 2)

Here, the prepreg was produced in the same manner as in Example 1 of the specification of International Publication WO2007/063960. The details are as follows.

1. Preparation of varnish of the first resin layer

Cyanate resin (manufactured by Lonza Japan Co., Ltd., Primaset PT-30, weight average molecular weight: about 2,600), 24% by weight, biphenyl dimethylene epoxy resin as epoxy resin (manufactured by Nippon Kayaku Co., Ltd., NC- 3000, epoxy equivalent 275) 24% by weight, as a phenoxy resin, a phenolic resin having a copolymer of a bisphenol A type epoxy resin and a bisphenol F type epoxy resin and having an epoxy group at the terminal portion (Japan) Manufactured by Epoxy Resins, EP-4275, weight average molecular weight 60,000) 11.8% by weight, and an imidazole compound as a hardening catalyst ("2-Benzene-4,5-dihydroxymethylimidazole" manufactured by Shikoku Chemical Industries, Ltd.) 0.2 % by weight dissolved in methyl b Ketone. Further, spherical molten cerium oxide (SO-25H, manufactured by Admatech Co., Ltd., average particle diameter: 0.5 μm) of 39.8 wt% and an epoxy decane type coupling agent (manufactured by Nippon Unicar Co., Ltd., A-187) were added as an inorganic filler. 0.2% by weight was stirred for 60 minutes using a high-speed stirring device to prepare a resin varnish having a resin composition of 70% by weight (composition of A-4 of Table 3).

2. Preparation of varnish of second resin layer

A novolac type cyanate resin (manufactured by Lonza Japan Co., Ltd., Primaset PT-30, weight average molecular weight: about 2,600), which is a thermosetting resin, 15% by weight of a biphenyl dimethylene epoxy resin as an epoxy resin. (manufactured by Nippon Kayaku Co., Ltd., NC-3000, epoxy equivalent 275) 8.7% by weight, and a biphenyl dimethylene phenol resin as a phenol resin (manufactured by Nippon Kayaku Co., Ltd., GPH-65, hydroxyl equivalent 200) 6.3 wt% was dissolved in methyl ethyl ketone. Further, spherical molten cerium oxide (SO-25H, manufactured by Admatech Co., Ltd., average particle diameter: 0.5 μm) of 69.7 wt% and an epoxy decane type coupling agent (manufactured by Nippon Unicar Co., Ltd., A-187) were added as an inorganic filler. 0.3% by weight was stirred for 60 minutes using a high-speed stirring device to prepare a varnish of a second resin layer having a resin composition of 70% by weight (composition of B-5 of Table 3).

3. Manufacture of carrier materials

A polyethylene terephthalate film (manufactured by Mitsubishi Chemical Polyester Co., Ltd., SFB-38, thickness: 38 μm, width: 480 mm) was used as a carrier film, and the varnish of the above first resin layer was applied by a notch wheel coating device. The resin layer was formed by drying at 170 ° C for 3 minutes to form a resin layer having a thickness of 9 μm and a width of 410 mm in the width direction of the carrier film, thereby obtaining a carrier material I (final formation of the first Resin layer). Further, the amount of the varnish of the applied second resin layer is adjusted by the same method so that the resin layer having a thickness of 14 μm and a width of 360 mm is located at the center of the width direction of the carrier film to form the resin. The layer was obtained to obtain a carrier material II (finally forming a second resin layer).

4. Manufacturing of prepreg

A prepreg was produced by a vacuum laminating apparatus and a hot air drying apparatus using a glass woven fabric (cloth type #1015, width 360 mm, thickness 15 μm, basis weight 17 g/m ² ) as a fiber base material. Specifically, the carrier material I and the carrier material II are respectively placed on both sides of the glass woven fabric so as to be located at the center of the width direction of the glass woven fabric, and 80 ° C is used under a reduced pressure of 1330 Pa. The lamination rolls are joined. Here, in the inner region of the width direction of the glass woven fabric, the carrier material I and the resin layer of the carrier material II are respectively bonded to both sides of the fiber cloth, and the carrier is placed on the outer side of the width direction of the glass woven fabric. The resin layers of the material I and the carrier material II are bonded to each other. Then, the bonded body was passed through a lateral transfer type hot air drying device set to 120 ° C for 2 minutes, and heat treatment was performed without applying pressure to obtain a thickness of 30 μm (first resin layer: 5 μm, Fiber substrate: 15 μm, second resin layer: 10 μm) prepreg.

(evaluation method)

The prepreg produced by the above examples and comparative examples was evaluated.

(with or without interface)

The cross section perpendicular to the thickness direction of each prepreg was observed by SEM (magnification: 1000 times), and whether the interface between the first resin layer and the second resin layer was confirmed was confirmed. The results are shown in Table 4, and the SEM photographs of Examples 1, 5, and 6 are shown in Figs. 8 to 10, and the SEM photographs of Comparative Examples 1 and 2 are shown in Figs. Further, in the prepregs of Examples 5 and 6, the first resin layer directly contacts the surface of the fiber base material, and the second resin layer protrudes to the outside of the fiber base material, and the first resin layer is not directly The area in contact with the fibrous substrate.

(impregnation rate)

The cross section perpendicular to the thickness direction of each prepreg was observed by SEM (magnification: 500 times), and the average value B of the distance from the surface of the glass cloth to the interface between the first resin layer and the second resin layer was calculated (measurement of 10 parts) ). Then, the average value A of the thickness of the glass cloth (measured at 10 locations) was calculated, and the impregnation rate was calculated at B/A × 100 (%). The results are shown in Table 4. Furthermore, the thickness of the glass cloth is measured by the intersection of the longitudinal and transverse threads.

(performance of resin layer)

Peel strength

The peeling strength of the first resin layer and the second resin layer of each of the examples and the comparative examples was measured. The measurement method is as follows. The 90° peel strength A after the first resin layer 3 of the prepreg 1 and the copper foil were superposed on each other and heat-treated in the air for 1 hour under a load of 2 MPa and a temperature of 220 ° C was measured. Further, the 90° peel strength B after the second resin layer 4 of the prepreg and the copper foil were superposed on each other and heat-treated in the air for 1 hour under the conditions of a load of 2 MPa and a temperature of 220 ° C was measured. The peel strength was measured by peeling off the resin layer on the copper foil in the direction of 90 degrees in accordance with the 90 degree peeling method of JIS C 6481. Specifically, the 90-degree peel strength at the time of peeling off the resin layer was measured at a speed of 50 mm per minute at 25 ° C using a 90-degree peeling tester. Further, the copper foil was a copper foil having a thickness of 2 μm (surface roughness Rz = 2.0 μm, manufactured by Mitsui Metals, Inc., trade name MT Ex-2). The results are shown in Table 4.

2. Buried

An inner circuit substrate having a circuit pattern, a circuit thickness of 18 μm, and a copper residual ratio of 50% was prepared. The prepreg was placed so that the second resin layer was in contact with the circuit pattern of the inner layer circuit board, and subjected to pressure heating molding (1 MPa, 200 ° C, 90 minutes) to obtain ten substrates. The cross section of each substrate was observed with a microscope. Further, the embedding property of the second resin layer was evaluated.

◎: The embedding property of all the substrates was excellent.

○: A minute gap which is substantially problem-free is generated at the end of the plate.

×: Buried is insufficient, and a large amount of voids are generated.

The results are shown in Table 4.

(reliability between channels)

The prepreg obtained in the eight examples and the comparative examples was superposed, and a copper foil having a thickness of 12 μm was laminated on both surfaces, and subjected to heat and pressure molding at a pressure of 4 MPa and a temperature of 200 ° C for 2 hours, thereby obtaining copper foil on both sides. Laminated board. When the prepreg is superposed, the prepreg is deposited such that the first resin layer and the second resin layer are alternately arranged. Thereafter, a through-hole having a diameter of 0.15 mm and a wall-to-wall distance of 100 μm was opened by a carbon dioxide laser using a conformal mask, and then plating was performed to form a circuit wiring at 130 ° C, 85% RH, and applied voltage. The insulation resistance was measured at 20 V for 500 h under 20 V conditions. The sample used for the measurement was prepared to have N=10.

◎: All samples are 1.0 × 10 ⁷ Ω or more

○: The number of samples which are 1.0 × 10 ⁷ Ω or more is 8 or more and less than 9

×: less than 8 samples of 1.0 × 10 ⁷ Ω or more

(lowest melt viscosity)

The measurement conditions of the lowest melt viscosity are as follows. The results are shown in Table 4. In the examples and comparative examples, the lowest melt viscosity of the first resin layer and the second resin layer at 50 to 150 ° C was measured. Here, the varnish of the first resin composition obtained in each of the above Examples and Comparative Examples and the varnish of the second resin composition were applied by a knurling wheel coating device, and dried at 170 ° C by a drying device. In minutes, a film having a thickness of 5 μm was formed, which was used as a measurement object. Here, the measurement result here is the same as the lowest melt viscosity of the first resin layer and the second resin layer in the state of the prepreg. The measurement conditions are as follows.

Dynamic viscoelasticity measuring device (manufactured by Anton Paar, the device name Physica) MCR-301)

Frequency: 62.83 rad/sec

Measurement temperature: 25~200°C, 3°C/min

Geometric shape: parallel plate

Plate diameter: 10 mm

Board spacing: 0.1 mm

Load (normal force): 0 N (fixed)

Strain: 0.3%

Measuring environment: air

(resin flow rate (% by weight))

The prepregs of the examples and the comparative examples were measured in accordance with IPC-TM-650 method 2.3.17. That is, as shown in Fig. 7, the prepregs of the examples and the comparative examples were cut into squares of 102 mm × 102 mm, and four sheets were superposed thereon, and the weight (W ₀ (g)) was measured. Further, a release film is attached to both sides of the outermost layer of the prepreg (product name: Sepaniumu 20M2C-S, manufacturer: Sun-Aluminum Industrial Co., Ltd., size: 200 mm × 240 mm) (Fig. 7(a) ). Thereafter, a prepreg was placed between two SUS plates, and heated and pressurized to 171 ° C and 1.38 MPa, and hot plate pressing was performed for 5 minutes ( FIG. 7( b )). Then, the release film was peeled off, and the prepreg was cut out into a cylindrical shape having a diameter of 81 mm so that the lamination direction of the prepreg was in the height direction (Fig. 7(c)), and the obtained cylindrical prepreg was measured. Body weight (W ₂ (g)). The resin flow rate was determined according to the formula (1). The results are shown in Table 3. Further, in the formula (1), % is % by weight.

(resin extension)

The prepreg of the examples and comparative examples cut into 200 mm × 200 mm was pressed using a hot press apparatus of CVP300 manufactured by Nichigo-Morton Co., Ltd., and the amount of resin protrusion was measured. Specifically, the prepreg of the above-described embodiment or the comparative example was placed between two rubber sheets sandwiched between two hot plates (SUS 1.5 mm) of the hot press apparatus at 120 ° C and 2.5 MPa. Press for 60 seconds under conditions. The rubber sheet was set to a ruthenium rubber having a rubber hardness of 60° and a thickness of 3 mm as measured according to JIS K 6253 A. The results are shown in Table 4.

(layer thickness)

The prepreg obtained in the eight examples and the comparative examples was superposed, and a copper foil having a thickness of 12 μm was superposed on both surfaces, and heated and pressed at a pressure of 3.5 MPa and a temperature of 200 ° C for 2 hours, thereby obtaining copper foil on both sides. The layered body. In the laminate, the first resin layer was placed on the copper foil side of the upper layer in the four prepreg systems on the upper layer side, and the first resin layer was placed on the copper foil side of the lower layer in the four prepreg systems. Thereafter, all of the copper foil was removed by etching with an etching solution (ferric chloride), and the thickness of the laminate (400 mm square) was measured at a pitch of 40 mm to calculate a maximum-minimum value. The results are shown in Table 4.

◎: less than 10 μm

△: 10 μm or more and less than 30 μm

×: 30 μm or more

(warping of laminated body)

The prepreg obtained in the eight examples and the comparative examples was superposed, and a copper foil having a thickness of 12 μm was superposed on both surfaces, and heated and pressed at a pressure of 3.5 MPa and a temperature of 200 ° C for 2 hours, thereby obtaining copper foil on both sides. The layered body. In the laminate, the first resin layer was placed on the copper foil side of the upper layer in the four prepreg systems on the upper layer side, and the first resin layer was placed on the copper foil side of the lower layer in the four prepreg systems. Thereafter, all of the copper foil was removed by etching with an etching solution (ferric chloride), and a single piece warpage of 50 mm square was measured. The results are shown in Table 4.

◎: less than 200 μm

×: 200 μm or more

(heat resistance)

The prepreg obtained in the eight examples and the comparative examples was superposed, and a copper foil having a thickness of 12 μm was superposed on both surfaces, and heated and pressed at a pressure of 3.5 MPa and a temperature of 200 ° C for 2 hours, thereby obtaining copper foil on both sides. The layered body. In the laminate, the first resin layer was placed on the copper foil side of the upper layer in the four prepreg systems on the upper layer side, and the first resin layer was placed on the copper foil side of the lower layer in the four prepreg systems. Then, heat treatment and moisture absorption treatment according to the JEDEC standard level 2 were carried out to evaluate the moisture absorption and heat resistance reliability. Specifically, the laminate is pre-dried at 125 ° C / 24 hours, and then subjected to a moisture absorption treatment at 85 ° C and 60% RH for 196 hours, and further passed a reflow temperature of a corresponding lead-free solder having a peak temperature of 260 ° C. The infrared reflow oven of the reflow profile was used 20 times. The appearance of the laminate was observed every time the reflow was observed to confirm the presence or absence of expansion. Further, after the infrared reflow furnace was used for 10 times, the expansion inside the laminate was also investigated using an ultrasonic microscope (SAT) (ultrasonic imaging device). The results are shown in Table 4.

◎: After 20 times through the reflow furnace, the appearance did not swell. There is no expansion inside the laminate.

○: After 20 passes through the reflow furnace, the appearance did not swell. There is expansion inside the laminate.

×: The appearance of the reflow furnace is expanded after 1 to 5 times.

In the first to sixth embodiments, the second resin layer is impregnated into the fibrous base material at least at a position from the surface of the fibrous base material to 90% of the thickness of the fibrous base material, so that the resin composition having a high impregnation property is used. The second resin layer may be formed, and the resin composition of the first resin layer is not limited to those having higher impregnation properties. Further, in Examples 1 to 6, the second resin layer was impregnated into the fiber base material at least at a position from the surface of the fiber base material to 90% of the thickness of the fiber base material, so that the reliability between the passages was also good. Moreover, in the first to sixth embodiments, it is confirmed It is recognized that the first resin layer is in contact with the second resin layer to have an interface. It is considered that the ratio η1/η2 of the lowest melt viscosity η1 of the first resin layer to the lowest melt viscosity η2 of the second resin layer is 1.1 times or more, so that a clear interface can be formed. In addition, it is considered that the second resin layer is easily impregnated into the fiber base material by setting η1/η2 to 1.1 times or more. In addition, in Examples 1 to 6, since η1/η2 is 100 or less, the adhesion between the first lipid layer and the second resin layer is excellent. Further, in Examples 1 to 6, the peel strength A of the first resin layer was higher than the peel strength B of the second resin layer, and the peel strength of the first resin layer and the second resin layer became the required strength. Further, it was found that the embedding property of the circuit pattern was also good, and the first resin layer and the second resin layer exhibited desired characteristics. Further, the resin flow rate was also 15% by weight or more, and the embedding property of the circuit was excellent. Further, the resin flow rate is 50% by weight or less, and the outflow of the resin can be suppressed at the time of pressing. Further, since the amount of protrusion of the resin is 5% by weight or less, the thickness uniformity of the laminated sheet is good, and the occurrence of warpage can be suppressed. Further, in Examples 1 to 4, since the second resin layer was made of cerium oxide having an average particle diameter of 50 nm, the heat resistance was extremely good. Further, in Examples 1 to 4, since the second resin layer was made of cerium oxide having an average particle diameter of 50 nm, the reliability between the passages was extremely high. It is considered that the nano cerium oxide is introduced into the fiber bundle to form a state in which nano cerium oxide adheres to the fiber, thereby improving the reliability between the channels. Further, the prepreg using the stretch naphthyl ether type epoxy resin has low water absorption and low thermal expansion.

In Comparative Example 1, since the varnish having the same viscosity is impregnated into the fiber base material, the impregnation speed of the first resin layer and the second resin layer is approximately the same, and the impregnation rate is about 50%. In addition, in Comparative Example 2, since the resin sheets having the lowest melt viscosity are bonded to each other on the fiber base material, the impregnation speed of the first resin layer and the second resin layer is the same, and the impregnation rate is the same. About 50%. In the first and second comparative examples, it is necessary to impregnate the first resin layer and the second resin layer to the same extent. In the substrate, therefore, the choice of resin composition is limited. Further, in Comparative Example 1, the interface between the first resin layer and the second resin layer could not be confirmed, and the first resin layer and the second resin layer were mixed. Therefore, the peeling strength of the first resin layer was weaker than that of Example 1. Further, the embedding property of the circuit pattern was inferior to that of the first embodiment, and the first resin layer and the second resin layer could not exhibit the desired characteristics. Further, the reliability between the vias is poor, and the thickness uniformity of the laminated sheets is poor, and warpage occurs. In Comparative Example 1, it was considered that the reliability between the passages was caused by the uneven mixing of the varnish constituting the first resin layer and the varnish constituting the second resin layer. In Comparative Example 2, the interface between the first resin layer and the second resin layer could not be confirmed, and the first resin layer and the second resin layer were mixed. Therefore, the peeling strength of the first resin layer is lower than the desired value. Further, in Comparative Example 2, the laminate was warped. This is because the thickness of the first resin layer on the copper foil side is low, so that the thickness of the laminated plate is uneven.

The present application claims the priority of Japanese Patent Application No. 2012-41917, filed on Feb. 28, 2012, and the priority of Japanese Patent Application No. 2012-41886, filed on Feb. The content is incorporated herein.

1‧‧‧Prepreg

2‧‧‧Fiber substrate

3‧‧‧1st resin layer

4‧‧‧2nd resin layer

42‧‧‧The Ministry of Coverage

43‧‧‧2nd Impregnation Department

F‧‧‧ interface

T, ta, tb‧‧‧ thickness

Claims (25)

A prepreg comprising: a fiber base material, a first resin layer covering a surface side of the fiber base material and comprising a first resin composition; and the other surface side covering the fiber base material, and the first surface a second resin layer composed of a second resin composition having a different resin composition, and the second resin layer is impregnated into the fiber substrate from at least 90% of the thickness of the fiber substrate from the other surface of the fiber substrate in. The prepreg according to claim 1, wherein the first resin layer is in contact with the second resin layer to form an interface. The prepreg according to claim 1, wherein the first resin layer is a layer provided with a metal layer on the upper surface thereof, and the second resin layer is a layer for embedding the circuit. The prepreg according to any one of claims 1 to 3, wherein the first resin layer and the second resin layer are thermosetting layers and are semi-hardened. The prepreg according to claim 1, wherein the second resin layer is impregnated into the fiber base material, and the first resin layer is in contact with the second resin layer to form an interface, and the first resin layer and the first resin layer are The interface of the resin layer is located outside the fiber substrate. The prepreg according to claim 1, wherein the content of the thermoplastic resin of the first resin layer is higher than that of the second resin layer The content of the thermoplastic resin. The prepreg according to the first aspect of the invention, wherein the first resin layer of the prepreg is overlapped with the copper foil, and the 90° peel strength after heat treatment for 1 hour under a load of 2 MPa and a temperature of 220 ° C A is higher than the 90° peel strength B after the second resin layer of the prepreg is superposed on the copper foil and heat-treated for 1 hour under the conditions of a load of 2 MPa and a temperature of 220 °C. A prepreg according to claim 7 wherein the 90° peel strength A-90° peel strength B ≧ 0.1 kN/m. For example, the prepreg of the first application of the patent scope, wherein the resin flow rate is measured by heating and pressurizing for 5 minutes at 171±3°C and 1380±70 kPa according to the IPC-TM-650 method 2.3.17. When it is heated and pressurized at 120 ° C and 2.5 MPa in a state in which the prepreg is held by one of the opposite rubber sheets in a state of 15% by weight or more and 50% by weight or less, the above-mentioned The total weight of the first resin layer and the second resin layer exposed on the outer edge of the fiber base material is 5% or less based on the total weight of the entire first resin layer and the entire second resin layer, and the rubber sheet satisfies the lower (i) to (iii), (i) The rubber hardness measured according to JIS K 6253 A is 60° (ii) The thickness is 3 mm (iii) The material is 矽. The prepreg according to the first aspect of the invention, wherein the first resin layer contains a thermoplastic resin, and the thermoplastic resin contains any one of a phenoxy resin, a polyvinyl acetal resin, and a polyamidamide resin. More than one species. The prepreg according to claim 1, wherein the second resin layer contains an epoxy resin, a cyanate resin, and an inorganic filler. The prepreg according to the first aspect of the invention, wherein at least one of the first resin layer and the second resin layer has a naphthalene skeleton and has a naphthalene skeleton via an oxygen atom and another exoaryl group. A bonded epoxy resin. The prepreg according to the first aspect of the invention, wherein the prepreg system is produced by: forming a first resin sheet that is a first resin layer and the fiber substrate with respect to the first resin layer; The second resin sheet which is the second resin layer or the liquid composition containing the second resin composition is impregnated from the other side of the fiber substrate. The prepreg according to the first aspect of the invention, wherein the lowest melt viscosity η1 of the first resin layer in the range of 50 ° C or more and 150 ° C or less when the temperature is raised at a temperature increase rate of 3 ° C / min at 25 ° C The ratio η1/η2 of the lowest melt viscosity η2 of the resin layer is 1.1 or more and 100 or less. The prepreg according to claim 1, wherein the second resin layer contains cerium oxide having a particle diameter of 50 nm or less. The prepreg according to claim 15, wherein the fibrous substrate is a glass cloth, and the above-mentioned ceria is present in a strand of the glass cloth. A substrate having a cured body of a prepreg according to claim 1 and having a circuit layer, wherein the circuit layer is embedded in the second resin layer of the cured body of the prepreg, and A metal layer is provided on the first resin layer of the cured body of the prepreg. A semiconductor device comprising: a substrate of claim 17; and a semiconductor device mounted on the substrate. A method for producing a prepreg, comprising: a step of pressing a first resin sheet against one surface of a fiber base material and providing a first resin layer composed of a first resin composition, on the other side of the fiber base material a step of forming a second resin layer composed of a second resin composition different from the first resin composition, and forming at least the other surface of the fiber substrate in the step of forming the second resin layer The second resin layer of the fiber base material is impregnated with 90% of the thickness of the fiber base material. The method for producing a prepreg according to claim 19, wherein the first resin sheet has a minimum melt viscosity of 1000 Pa at 50 to 150 ° C. s above and 25000 Pa. s below. The method for producing a prepreg according to claim 19, wherein in the step of forming the second resin layer, a liquid second resin composition is supplied to the other surface side of the fiber substrate. The method of producing a prepreg according to claim 19, wherein in the step of forming the second resin layer, the second resin sheet serving as the second resin layer is supplied to the other surface side of the fiber base material. The second resin sheet is heated and impregnated into the fiber base material, and the lowest of the first resin sheet in the range of 50° C. or higher and 150° C. or lower at 25° C. at a temperature increase rate of 3° C./min. Melt viscosity η1 and the second resin sheet The ratio η1/η2 of the low melt viscosity η2 is 1.1 or more and 100 or less. The method for producing a prepreg according to claim 19, wherein in the step of pressing the first resin sheet onto one surface of the fiber base material, the first resin sheet is directly or indirectly The first resin sheet is continuously conveyed along the outer peripheral surface of the stacking roll in contact with the surface of the stacking roll, and the portion of the stacking roll that is in contact with the first resin sheet passes through the first resin sheet. The fiber substrate is continuously conveyed toward the stacking roll in such a manner that the stacking rolls are in contact with each other. The method for producing a prepreg according to claim 19, wherein the first resin sheet is wound into a roll, the first resin sheet is fed from the roll, and the first resin sheet is pressed. In the above step on one side of the fiber base material, the fed first resin sheet is pressed against one surface of the fiber base material. The method for producing a prepreg according to claim 19, wherein the first resin sheet is formed on a support, and the step of pressing the first resin sheet onto one side of the fiber substrate is the above-described step The first resin sheet on the support is pressed against one surface of the fiber base material.