WO2013128841A1

WO2013128841A1 - Prepreg and prepreg manufacturing method

Info

Publication number: WO2013128841A1
Application number: PCT/JP2013/000891
Authority: WO
Inventors: 猛八月朔日; 恭史瀧本; 晴行秦野; 亘平穴田
Original assignee: 住友ベークライト株式会社
Priority date: 2012-02-28
Filing date: 2013-02-19
Publication date: 2013-09-06
Also published as: TW201343740A; JP2013209626A; JP6102319B2; KR20140127803A; TWI575003B

Abstract

A prepreg (1) is provided with: a fiber base material (2); a first resin layer (3), which covers one surface of the fiber base material (2), and which is composed of a first resin composition; and a second resin layer (4), which covers the other surface of the fiber base material (2), and which is composed of a second resin composition different from the first resin composition. The second resin layer (4) is impregnated with the fiber base material (2) to at least 90% of the thickness of the fiber base material (2) from the other surface of the fiber base material (2).

Description

Prepreg and prepreg manufacturing method

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

In recent years, in order to reduce the size and thickness of electronic components and electronic devices, it has been required to reduce the size and thickness of circuit boards and the like used therefor. In order to meet this requirement, a circuit board having a multilayer structure is used and each layer is thinned.

In general, in order to make the circuit board thinner, a method of forming a circuit pattern on one surface of the prepreg and embedding the circuit pattern with another prepreg adjacent to the prepreg is employed.
Patent Document 1 discloses a prepreg to be applied to a circuit board having such a structure.
Patent Document 1 discloses a prepreg in which two resin layers having different thicknesses are formed on both sides of a fiber base material.

JP 2004-216784 A

As described above, there is a method of forming a circuit pattern on one surface of a prepreg and embedding the circuit pattern with 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 the circuit pattern of the adjacent prepreg is embedded in the resin layer on the other side.
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 a circuit pattern embedding property. That is, different properties are required for the two resin layers of the prepreg.
In the prepreg described in Patent Document 1, since one resin layer is thicker than the other resin layer, the circuit pattern can be embedded in the thicker resin layer.
However, in the prepreg described in Patent Document 1, since both resin layers are composed of the same resin composition, it is difficult to satisfy the two different characteristics described above.

The present inventors have conceived that these resin layers are composed of different resin compositions so that the resin layer on one side of the prepreg and the resin layer on the other side meet different characteristics. However, when the fiber base material is impregnated with both different resin compositions, it is necessary to make the fiber base material have good impregnation properties, and the design of each resin composition is limited, It has been found that it is difficult to sufficiently achieve the desired characteristics in the layer.
The present invention has been invented based on such knowledge.

That is, according to the present invention,
A fiber substrate;
A first resin layer that covers one surface side of the fiber substrate and is composed of a first resin composition;
Covering the other surface side of the fiber substrate, and comprising a second resin layer composed of a second resin composition different from the first resin composition,
The second resin layer is provided with a prepreg in which the fiber base material is impregnated over at least 90% of the thickness of the fiber base material from the other surface of the fiber base material.

In such a prepreg, the second resin layer impregnated in the fiber base material is formed at least over 90% of the thickness of the fiber base material from the other surface of the fiber base material. Therefore, it is not necessary to impregnate the fiber base material with a large amount of the first resin layer. Therefore, the 1st resin composition which comprises the 1st resin layer is not restricted to the thing of the good impregnation property with respect to a fiber base material, The breadth of selection of a 1st resin composition spreads. And it can be set as the prepreg provided with the 1st resin layer which has a desired characteristic.

Furthermore, the manufacturing method of the prepreg mentioned above can also be provided.
That is, according to the present invention, the step of pressure-bonding the first resin sheet to one surface of the fiber substrate to provide the first resin layer made of the first resin composition;
Forming a second resin layer made of a second resin composition different from the first resin composition on the other surface side of the fiber substrate,
In the step of forming the second resin layer,
There is provided a method for producing a prepreg that forms a second resin layer impregnated in the fiber base material over at least 90% of the thickness of the fiber base material from the other surface of the fiber base material.

According to this manufacturing method, the second resin layer impregnated in the fiber base is formed at least over 90% of the thickness of the fiber base from the other surface of the fiber base. Therefore, it is not necessary to impregnate the fiber base material with a large amount of the first resin sheet. Accordingly, the first resin composition constituting the first resin layer is not limited to the one having good impregnation property to the fiber base material, and the selection range of the first resin composition is widened, and the first resin layer having desired characteristics is provided. Can be formed.
Furthermore, it is a substrate having a cured body of the prepreg described above,
With a circuit layer,
The second resin layer of the cured body of the prepreg embeds the circuit layer,
A substrate in which a metal layer is provided on the first resin layer of the cured prepreg can also be provided.
Also, with this substrate
A semiconductor device including a semiconductor element mounted on the substrate can also be provided.

According to the present invention, there are provided a prepreg and a method for manufacturing a prepreg that have different resin layers and can exhibit the desired characteristics of each resin layer more reliably.

The above-described object and other objects, features, and advantages will be further clarified by a preferred embodiment described below and the following drawings attached thereto.

It is sectional drawing of the prepreg concerning one Embodiment of this invention. It is sectional drawing of a prepreg. It is a schematic diagram which shows the manufacturing apparatus of a prepreg. It is a schematic diagram which shows the manufacturing apparatus of a prepreg. It is sectional drawing which shows a board | substrate. It is sectional drawing which shows a semiconductor device. It is a schematic diagram which shows the measuring method of a resin flow. 1 is a view showing a cross section of a prepreg of Example 1. FIG. 6 is a view showing a cross section of a prepreg of Example 5. FIG. 6 is a view showing a cross section of a prepreg of Example 6. FIG. 5 is a view showing a cross section of a prepreg of Comparative Example 1. FIG. 5 is a view showing a cross section of a prepreg of Comparative Example 2. FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all the drawings, the same components are denoted by the same reference numerals, and detailed description thereof is appropriately omitted so as not to overlap.
First, with reference to FIG. 1 and FIG. 3, the outline | summary of the prepreg of this embodiment and its manufacturing method is demonstrated.

FIG. 1 is a cross-sectional view showing a prepreg.
The prepreg 1 of this embodiment is
The fiber substrate 2, one surface side of the fiber substrate 2 is coated, the first resin layer 3 composed of the first resin composition, and the other surface side of the fiber substrate 2 are coated, The second resin layer 4 made of a second resin composition different from the one resin composition is provided, the first resin layer 3 and the second resin layer 4 are in contact with each other, and an interface F is formed.
The second resin layer 4 is impregnated in the fiber base material 2 over at least 90% of the thickness of the fiber base material 2 from the other surface of the fiber base material 2.
Here, the difference between the first resin composition and the second resin composition may be that the types of components constituting each resin composition may be different, or the composition ratio may be different. Good.

Moreover, the manufacturing method of the prepreg of this embodiment includes the step of pressing the first resin sheet 3 ′ on one surface of the fiber substrate 2 to provide the first resin layer 3 made of the first resin composition, and the fiber base. Forming a second resin layer 4 made of a second resin composition different from the first resin composition on the other surface side of the material 2. In the step of forming the second resin layer 4, the second resin layer 4 impregnated in the fiber base material 2 is formed over at least 90% of the thickness of the fiber base material 2 from the other surface of the fiber base material 2. To do.

Next, the prepreg and the method for manufacturing the prepreg will be described in detail with reference to FIGS.
<Prepreg>
Hereinafter, the prepreg 1 of this embodiment will be described in detail.
In the following description, the upper side in FIG. 1 (the same applies to the following drawings) will be described as “upper”, and the lower side will be described as “lower”.

A prepreg 1 shown in FIG. 1 includes a flat fiber substrate 2, a first resin layer 3 positioned on one surface (lower surface) side of the fiber substrate 2, and the other surface (upper surface) of the fiber substrate 2. And a second resin layer 4 located on the side. The prepreg 1 is for a printed wiring board (circuit board).

The fiber base material 2 has a function of improving the mechanical strength of the prepreg 1.
As this fiber base material 2, glass fiber base materials, such as glass woven fabric and glass nonwoven fabric,
Polyamide resin fibers, polyamide resin fibers such as aramid fibers such as aromatic polyamide resin fibers and wholly aromatic polyamide resin fibers, polyester resin fibers such as polyester resin fibers, aromatic polyester resin fibers, wholly aromatic polyester resin fibers, A synthetic fiber substrate composed of a woven or non-woven fabric mainly composed of at least one of polyparaphenylenebenzobisoxazole, polyimide resin fiber, fluororesin fiber, etc.,
Examples thereof include fiber base materials such as craft paper, cotton linter paper, and organic fiber base materials such as paper fiber base materials mainly composed of linter and kraft pulp mixed paper. Among these, any one or more fiber base materials can be used.

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

Examples of the glass constituting such a glass fiber substrate include E glass, C glass, A glass, S glass, D glass, NE glass, T glass, Q glass, H glass, UT glass, and L glass. Any one or more of these can be used. Among these, it is preferable that glass is S glass, T glass, UT glass, or Q glass. Thereby, the thermal expansion coefficient of a glass fiber base material can be made comparatively small, and for this reason, the prepreg 1 can be made as small as possible in the thermal expansion coefficient.

The average thickness T of the fiber substrate 2 is not particularly limited, but is preferably 150 μm or less, more preferably 100 μm or less, and even more preferably about 10 μm to 50 μm. By using the fiber substrate 2 having such a thickness, the mechanical strength of the prepreg 1 can be ensured and the thickness thereof can be reduced. Furthermore, workability when performing processing such as drilling on the prepreg 1 can also be improved.
In addition, the average thickness T of the fiber base material 2 measured 10 thicknesses from one surface of the fiber base material 2 to the other surface in the intersection part of the warp yarn and the weft of the fiber base material 2, and the average value It is obtained by calculating.

The first resin layer 3 is provided on one surface side of the fiber substrate 2, and the second resin layer 4 is provided on the other surface side. Moreover, the 1st resin layer 3 is comprised with the 1st resin composition, and the 2nd resin layer 4 is comprised with the 2nd resin composition different from the said 1st 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 a layer on which a wiring part (metal layer) is directly formed.
On the other hand, the second resin layer 4 is a layer in which the circuit layer is embedded.
In the present invention, the prepreg does not include a film that peels off during the production of the substrate.
The first resin layer 3 and the second resin layer 4 are semi-cured (B stage).

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

Further, in order to reliably embed the wiring portion (circuit) of the other prepreg 1, the second resin composition is set so that the second resin layer 4 has a minimum melt viscosity lower than that of the first resin layer 3. It is preferable that The minimum melt viscosity will be described later.
Moreover, in this embodiment, since the 2nd resin layer 4 impregnates the fiber base material 2 inside, the 2nd resin composition which comprises the 2nd resin layer 4 is a composition with the favorable impregnation property to the fiber base material 2. It is preferable that Each resin composition will be described in detail later.

As shown in FIG. 1, in this embodiment, the fiber base material 2 is impregnated with a part of the second resin layer 4 over the entire thickness direction.
More specifically, the second resin layer 4 includes an impregnation portion 43 impregnated in the fiber base 2 and a covering portion 42 that covers the surface (the other surface) of the fiber base 2. .
Here, the impregnation part 43 of the second resin layer 4 impregnates the fiber base material 2 from at least the surface covered with the covering part 42 of the fiber base material 2 to a position of 90% of the thickness of the fiber base material 2. Has been. In this embodiment, the impregnation part 43 impregnates the fiber base material 2 over the whole thickness of the fiber base material 2. Although the impregnation part 43 and the 1st resin layer 3 are contacting, the impregnation part 43 and the 1st resin layer 3 are not mutually mixed, Between the impregnation part 43 and the 1st resin layer 3, An interface F serving as a boundary is formed. Thereby, the function of each resin layer 3 and 4 can be exhibited reliably.

Further, the interface F between the impregnated portion 43 and the first resin layer 3 is located outside the fiber substrate 2.
More specifically, the first resin layer 3 is in contact with one surface of the fiber base 2, but is not impregnated inside the fiber base 2. And the impregnation part 43 and the 1st resin layer 3 contact | abut, and the interface F is formed. In the present embodiment, the first resin layer 3 is in direct contact with one surface of the fiber base material 2, but not limited to this, the impregnation portion 43 protrudes from one surface of the fiber base material 2. Thus, the first resin layer 3 may not directly contact one surface of the fiber base 2.
In the present embodiment, the average thickness T of the fiber base 2 is equal to the thickness -ta of the second resin layer 4.
As described above, since the interface between the second resin layer 4 and the first resin layer 3 exists outside the fiber substrate 2, there is no intersection between the interface and the fiber substrate 2.
Here, when there are many intersections between the interface and the fiber base material 2, there is a concern that the following phenomenon occurs. When a hole such as a via hole is formed in the prepreg, and a metal layer is formed inside the hole, metal ions enter from the intersection between the fiber base material 2 and the resin layer, and further migrate through the interface. Conceivable. In general, since the fiber base 2 and the resin layer have poor adhesion, it is considered that metal ions are likely to enter from the intersection of the fiber base 2 and the interface between the resin layers. As metal ions migrate, the insulation reliability between holes decreases.
On the other hand, by eliminating the intersection between the interface and the fiber base material 2, it is possible to prevent metal ions entering from between the fiber base material 2 and the second resin layer 4 from migrating the interface. Thereby, the insulation reliability between holes can be improved.
Moreover, in this embodiment, since the 1st resin layer 3 does not impregnate the fiber base material 2, it is not necessary to consider the impregnation property with respect to the fiber base material 2. FIG. And what is necessary is just to select the thing with good adhesiveness with a metal as the 1st resin layer 3, Therefore The breadth of the design of the 1st resin layer 3 can be expanded.
In addition, the interface of the 1st resin layer 3 and the 2nd resin layer 4 can be confirmed by observing the cross section orthogonal to the thickness direction of the prepreg 1 by SEM.
In addition, in the cross section perpendicular to the thickness direction of the prepreg 1, it is preferable that the interface between the first resin layer 3 and the second resin layer 4 is formed over the entire width direction of the prepreg 1. By setting it as such a structure, the function of each resin layer 3 and 4 can be exhibited reliably.
The first resin layer 3 is not impregnated in the fiber base material 2, and no other fiber base material exists in the first resin layer 3.

In addition, in this embodiment, although the impregnation part 43 impregnated the fiber base material 2 over the whole thickness of the fiber base material 2, not only this but the 1st resin layer 3 is also in the fiber base material 2. It may be impregnated. As shown in FIG. 2, the impregnation portion 43 of the second resin layer 4 extends from the surface (the other surface) covered with the covering portion 42 of the fiber base material 2 to a position of 90% or more of the thickness of the fiber base material 2. The fiber substrate 2 is impregnated. That is, the thickness ta1 of the impregnated portion 43 is 90% or more of the thickness T of the fiber base 2. Further, the fiber base material 2 is impregnated with the impregnation portion 31 of the first resin layer 3. The impregnation part 31 impregnates the fiber base material 2 from the surface (one surface) of the fiber base material 2 covered with the covering part 32 to a position of 10% or less of the thickness of the fiber base material 2. The thickness tb1 of the impregnation part 31 is 10% or less of the thickness T of the fiber base 2. The impregnation part 31 impregnates a region not impregnated by the impregnation part 43. And the 1st impregnation part 31 which is a part of 1st resin layer 3, and the 2nd impregnation part 43 which is a part of 2nd resin layer 4 are located in the fiber base material 2. FIG. In the fiber base material 2, the 1st impregnation part 31 (lower surface of the 1st resin layer 3) and the 2nd impregnation part 43 (upper surface of the 2nd resin layer 4) are contacting. Further, an interface F is formed at the boundary between the first impregnation portion 31 and the impregnation portion 43. The other points are the same as in FIG.

Thus, the impregnation part 43 impregnates the fiber base material 2 from the surface covered with the covering part 42 of the fiber base material 2 to a position of 90% or more of the thickness of the fiber base material 2, whereby the second resin The intersection between the interface between the layer 4 and the first resin layer 3 and the fiber substrate 2 can be reduced. Thereby, it can prevent that the metal ion which entered from between the fiber base material 2 and the 2nd resin layer 4 migrates the said interface. Thereby, the insulation reliability between holes can be improved.
In addition to this, the impregnation part 31 impregnates the fiber base material 2 from the surface of the fiber base material 2 covered with the covering part 32 to a position of 10% or less of the thickness of the fiber base material 2. Since the impregnation amount of the portion 31 is small, it is not necessary to consider the impregnation property of the impregnation portion 31 with respect to the fiber base material 2. For this reason, since the first resin layer 3 may be selected from those having good adhesion to metal, the design range of the first resin layer 3 can be widened.
Moreover, as shown in FIG. 2, when the 1st resin layer 3 and the 2nd resin layer 4 contact in the fiber base material 2, peeling arises between the 1st resin layer 3 and the 2nd resin layer 4. As shown in FIG. Can be prevented. That is, the first resin composition constituting the first resin layer 3 in the fiber base material 2 is obtained by impregnating the woven fiber base material 2 with the first resin layer 3 and the second resin layer 4. It can prevent that the 2nd resin composition which comprises the resin layer 4 gets caught, and peeling arises between the 1st resin layer 3 and the 2nd resin layer 4. FIG.

In addition, it can confirm that the 2nd resin layer 4 has impregnated the fiber base material 2 over the position of 90% of the thickness of the fiber base material 2 as follows. The average value T of the thickness of the fiber base material 2 is calculated, and 90% of this thickness is calculated (numerical value C). And the average value D (10 places measurement) of the distance from the other surface of the fiber base material 2 to the interface F of the 1st resin layer 3 and the 2nd resin layer 4 should just exceed the numerical value C.

Moreover, in order to form the interface F between the 1st resin layer 3 and the 2nd resin layer 4, although mentioned later in detail, the minimum melt viscosity (eta) 1 of the 1st resin layer 3, the 2nd resin layer 4 is mentioned, for example. The ratio (η1 / η2) of the minimum melt viscosity η2 is 1.1 times or more, and at the time of production, one of the layers is supplied to the fiber substrate 2 in the form of a sheet, and the other layer is varnished to form fibers. What is necessary is just to supply to the base material 2.

Further, the average thickness of the covering portion 42 of the second resin layer 4 and t _{a [μm],} among the first resin layer 3, the average thickness of the portion covering the one surface of the fiber substrate 2 t _b [[mu] m] and the time, _{t a} is preferably larger than _{t b.} A wiring part 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 sufficient thickness, when embedding the wiring portion of another prepreg 1 or another fiber base material in the second resin layer 4, The embedding can be performed reliably, that is, the embedding property to the wiring part of other prepreg 1 and other fiber base material is improved.

Specifically, the average thickness t _b is preferably 0.1 to 15 μm, and more preferably 1 to 10 μm. On the other hand, the average thickness _{t a} is preferably from 4 ~ 50 [mu] m, and more preferably 8 ~ 40 [mu] m.

The average thickness t _a and the average thickness t _b is measured 10 points at arbitrary intervals, obtained by calculating the average value.

The minimum melt viscosity (η1) of the first resin layer 3 and the minimum melt viscosity (η2) of the second resin layer 4 in the range of 50 to 150 ° C. when the temperature is increased from 25 ° C. at a rate of 3 ° C./min. ) 1 / η2 is preferably 1.1 or more and 100 or less. In addition, the minimum melt viscosity (η1) of the first resin layer 3 is higher than the minimum melt viscosity (η2) of the second resin layer 4. By doing in this way, while improving the impregnation property to the fiber base material 2 of the 2nd resin layer 4, it can prevent that the 1st resin layer 3 impregnates the fiber base material 2 in large quantities.
Further, by setting the minimum melt viscosity ratio η1 / η2 to 1.1 or more, the first resin layer 3 and the second resin layer 4 are not mixed, and the interface between the first resin layer 3 and the second resin layer 4 is achieved. Can be formed.
Moreover, there exists an effect of improving the adhesiveness of an interface by making minimum melt viscosity ratio (eta) 1 / (eta) 2 into 100 or less, especially 80 or less.
The measurement conditions for the minimum melt viscosity are as follows.
Using a dynamic viscoelasticity measuring device, measurement is performed under the conditions of a measurement frequency of 62.83 rad / sec, a temperature rising rate of 3 ° C./min, and 50 to 150 ° C.
Here, specifically, the minimum melt viscosity η1 of the first resin layer 3 is preferably 1000 Pa · s or more and 25000 Pa · s or less.
On the other hand, the minimum melt viscosity (η2) of the second resin layer 4 is preferably 50 Pa · s or more and 10000 Pa · s or less, more preferably 5000 Pa · s or less, and further 3000 Pa · s or less. desirable.
The minimum melt viscosity (η1) of the first resin layer 3 is 1.1 times or more the minimum melt viscosity (η2) of the second resin layer 4, and the minimum melt viscosity of each resin layer is in the above-described range. Thus, the prepreg impregnated in the fiber base material 2 over the position where the second resin layer 4 is at least 90% of the thickness of the fiber base material 2 can be easily manufactured.

Furthermore, it is preferable that the prepreg 1 of this embodiment also satisfies the following characteristics.
According to IPC-TM-650 Method 2.3.17, the resin flow measured by heating and pressurizing for 5 minutes under the conditions of 171 ± 3 ° C. and 1380 ± 70 kPa is 15 wt% or more and 50 wt% or less,
When the prepreg 1 is sandwiched between a pair of opposing rubber plates and heated and pressurized under the conditions of 120 ° C. and 2.5 MPa, the weight of the resin layer protruding from the outer edge of the fiber substrate 2 in plan view (first 1 resin layer 3 and the total weight of the second resin layer 4) is 5% or less with respect to the total weight of the entire first resin layer 3 and the entire second resin layer 4, and the rubber plate is the following (i) Satisfy (iii).
(I) Rubber hardness measured in accordance with JIS K 6253 A is 60 °
(Ii) Thickness 3mm
(Iii) Material is silicon

In accordance with IPC-TM-650 Method 2.3.17, the resin flow measured by heating and pressurizing for 5 minutes under the conditions of 171 ± 3 ° C. and 1380 ± 70 kPa is 15% by weight or more. A prepreg excellent in embedding property can be obtained. Moreover, when the upper limit of the resin flow is 50% by weight or less, the outflow of the resin layer from the prepreg can be suppressed when the prepreg is laminated and pressed. Therefore, when it is laminated on a core layer (see FIG. 5) such as the inner layer circuit board 13, the build-up is excellent in embedding of the circuit of the inner layer circuit board 13 and can suppress the outflow of the resin layer from the prepreg during the lamination press. Prepreg.
Further, when the prepreg 1 is sandwiched between a pair of opposed rubber plates and heated and pressurized under the conditions of 120 ° C. and 2.5 MPa, the weight of the resin layer protruding from the outer edge of the fiber substrate 2 in plan view is 5 The thickness uniformity of the obtained laminated board can be improved by setting it as the weight% or less. Therefore, when laminated on the inner layer circuit board 13, the prepreg has excellent circuit embedding properties, can suppress the outflow of the resin layer from the prepreg during the lamination press, and can improve the thickness uniformity. Becomes feasible.
In addition, the lower limit of the weight of the resin layer protruding from the outer edge of the fiber substrate 2 in plan view when heated and pressurized under the conditions of 120 ° C. and 2.5 MPa with the prepreg 1 sandwiched between a pair of opposing rubber plates Although a value is not specifically limited, For example, it is 0.1 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 preferably have the following compositions.

The first resin composition includes, for example, a thermosetting resin, and includes at least one of a curing aid (for example, a curing agent and a curing accelerator) and an inorganic filler as necessary. .

In order to improve the adhesion with the metal constituting the wiring part, a method of using a thermosetting resin having excellent adhesion with the metal, a curing aid that improves the adhesion with the metal (for example, curing agent, curing acceleration) And the like, a method using an acid-soluble material as an inorganic filler, a method using an inorganic filler and an organic filler in combination, a method using a specific thermoplastic resin, and the like.

Examples of such thermosetting resins include urea (urea) resins, melamine resins, bismaleimide resins, polyurethane resins, resins having a benzoxazine ring, cyanate ester resins, bisphenol S type epoxy resins, bisphenol F type epoxy resins, and bisphenols. An epoxy resin such as a copolymerized epoxy resin of S and bisphenol F is preferably used. Any one or more of these can be used.
Of these, it is particularly preferable to use a cyanate resin (including a prepolymer of cyanate resin) as the thermosetting resin.

Such a cyanate resin can be obtained, for example, by reacting a cyanogen halide with a phenol and prepolymerizing it by a method such as heating, if necessary.

Specific examples of cyanate resins include novolak-type cyanate resins, bisphenol A-type cyanate resins, bisphenol E-type cyanate resins, and tetramethylbisphenol F-type cyanate resins. Any one or more of these can be used. Among these, it is preferable that cyanate resin is a novolak-type cyanate resin.

If a novolac-type cyanate resin is used, the cross-link density increases in the first resin layer 3 after curing after the substrate 10 (see FIG. 5) described later is manufactured, so that the first resin layer 3 (obtained after curing) is obtained. The heat resistance and flame retardancy of the substrate) can be improved.

Here, the improvement in heat resistance is thought to be due to the fact that the novolac-type cyanate resin forms a triazine ring after the curing reaction. In addition, the flame retardancy is improved because the novolak-type cyanate resin has a high proportion of benzene rings due to its structure, so that the benzene rings are easily carbonized (graphitized), and the first resin layer 3 after curing has carbonized portions. It is thought that it originates in what happens.

Furthermore, if a novolac-type cyanate resin is used, even if the prepreg 1 is thinned (for example, 35 μm or less in thickness), excellent rigidity can be imparted to the prepreg 1. 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.

In the novolak-type cyanate resin represented by the formula (I), the average number of repeating units “n” is not particularly limited, but is preferably 1 to 10, and more preferably 2 to 7. When the average number of repeating units “n” is less than the lower limit, the novolac cyanate resin is easily crystallized, and thus the solubility in a general-purpose solvent decreases. For this reason, the first resin composition may be difficult to handle depending on the content of the novolac-type cyanate resin. In addition, when the prepreg 1 is manufactured, tackiness occurs, and when the prepregs 1 come into contact with each other, a phenomenon occurs in which the prepregs 1 adhere to each other or the first resin composition of one prepreg 1 shifts to the other prepreg 1. Sometimes. On the other hand, if the average number of repeating units “n” exceeds the upper limit, the viscosity of the first resin composition becomes too high, and the efficiency (formability of the first resin layer 3) when producing the prepreg 1 is lowered. There is a case.

Moreover, when using together the hardening | curing agent or hardening accelerator which improves adhesiveness with a metal, in addition to the above-mentioned thermosetting resin, for example, novolak type such as phenol novolak resin, cresol novolak resin, bisphenol A novolak resin, etc. Phenolic resins, unmodified resol phenolic resins, phenolic resins such as oil-modified resol phenolic resins modified with tung oil, linseed oil, walnut oil, etc., bisphenol types such as bisphenol A epoxy resin, bisphenol F epoxy resin, etc. Other thermosetting such as epoxy resin, novolak epoxy resin, cresol novolak epoxy resin such as cresol novolak epoxy resin, epoxy resin such as biphenyl type epoxy resin, unsaturated polyester resin, diallyl phthalate resin, silicone resin It is also possible to use fat. Any one or more of these can be used.

The content of the thermosetting resin is not particularly limited, but is preferably 5 to 50% by weight, 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 lower limit, depending on the type of the thermosetting resin, the viscosity of the varnish of the first resin composition becomes too low, and it becomes difficult to form the prepreg 1. There is a case. On the other hand, if the content of the thermosetting resin exceeds the upper limit, the amount of other components is too small, and the mechanical strength of the prepreg 1 may decrease depending on the type of the thermosetting resin. .
In addition, in this specification, when it says a resin composition, it means what remove | excluded the solvent and the content of each component is prescribed | regulated by making components other than a solvent into 100 weight part.

Examples of the above-described curing aid (for example, a curing agent, a curing accelerator, etc.) include tertiary amines such as triethylamine, tributylamine, diazabicyclo [2,2,2] octane, 2-ethyl-4-ethylimidazole, 2-phenyl-4-methylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 2,4-diamino-6- [2'-methyl Imidazolyl- (1 ′)]-ethyl-s-triazine, 2,4-diamino-6- (2′-undecylimidazolyl) -ethyl-s-triazine, 2,4-diamino-6- [2′-ethyl Imidazole compounds such as -4-methylimidazolyl- (1 ′)]-ethyl-s-triazine and 1-benzyl-2-phenylimidazole It is. Any one or more of these can be used.

Among these, the curing aid is selected from imidazole compounds having two or more functional groups selected from an aliphatic hydrocarbon group, an aromatic hydrocarbon group, a hydroxyalkyl group, and a cyanoalkyl group. In particular, 2-phenyl-4,5-dihydroxymethylimidazole is more preferable.

Examples of the first resin composition include organic metal salts such as zinc naphthenate, cobalt naphthenate, tin octylate, cobalt octylate, bisacetylacetonate cobalt (II), and trisacetylacetonate cobalt (III). Further, phenol compounds such as phenol, bisphenol A and nonylphenol, organic acids such as acetic acid, benzoic acid, salicylic acid and paratoluenesulfonic acid can be used in combination. Any one or more of these can be used.

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

The first resin composition preferably contains an inorganic filler. Thereby, even if the prepreg 1 is made thin (for example, a thickness of 35 μm or less), the prepreg 1 having excellent mechanical strength can be obtained. Furthermore, the low thermal expansion of the prepreg 1 can be improved.

Examples of the inorganic filler include talc, alumina, glass, silica such as fused silica, mica, aluminum hydroxide, magnesium hydroxide, and the like. Any one or more of these can be used. Further, depending on the purpose of use of the inorganic filler, a crushed or spherical one is appropriately selected. Among these, from the viewpoint of excellent low thermal expansibility, the inorganic filler is preferably silica, and more preferably fused silica (particularly spherical fused silica).

The average particle size of the inorganic filler is preferably 0.01 to 5.0 μm, and more preferably 0.2 to 2.0 μm. Incidentally, the average particle size is d _50, can be measured as follows.
The inorganic filler is dispersed in water by ultrasonic waves, and the particle size distribution of the inorganic filler is measured on a volume basis by a dynamic light scattering particle size distribution measuring device (LB-550, manufactured by HORIBA). The median diameter is averaged. The particle diameter was taken.

In particular, as the inorganic filler, spherical fused silica having an average particle size of 5.0 μm or less is preferable.

In order to improve the adhesion between the first resin layer 3 and the wiring part, an acid-soluble inorganic filler may be used as the inorganic filler. Thereby, when the wiring part (conductor layer) is formed on the first resin layer 3 by plating, the adhesion (plating adhesion) of the wiring part to the first resin layer 3 can be improved. Examples of the acid-soluble inorganic filler 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 part, an inorganic filler and an organic filler may be used in combination. Examples of the organic filler include resin fillers such as liquid crystal polymer and polyimide.

When the inorganic filler is used, the content thereof is not particularly limited, but is preferably 20 to 70% by weight, more preferably 30 to 60% by weight of the entire first resin composition.

When using a cyanate resin (particularly a novolac-type cyanate resin) as the thermosetting resin, it is preferable to use an epoxy resin (substantially free of halogen atoms) in combination. Examples of the epoxy resin include phenol novolac type epoxy resin, bisphenol type epoxy resin, naphthalene type epoxy resin, arylalkylene type epoxy resin, and the like. Any one or more of these can be used.

Among these, the epoxy resin is preferably at least one of a naphthalene type epoxy resin and an arylalkylene type epoxy resin. By using these epoxy resins, moisture absorption solder heat resistance (solder heat resistance after moisture absorption) and flame retardancy can be improved in the cured first resin layer 3.

The naphthalene type epoxy resin means one having a naphthalene skeleton in a repeating unit. As the naphthalene type epoxy resin, a naphthol type epoxy resin, a naphthalene diol type epoxy resin, a bifunctional to tetrafunctional epoxy type naphthalene resin, a naphthylene ether type epoxy resin and the like are preferable. Any one or more of these can be used.
Thereby, heat resistance and low thermal expansibility can further be improved. In addition, since the naphthalene ring has a higher π-π stacking effect than the benzene ring, it is particularly excellent in low thermal expansion and low thermal shrinkage. Furthermore, since the polycyclic structure has a high rigidity effect and the glass transition temperature is particularly high, the change in heat shrinkage before and after reflow is small. As the naphthol type epoxy resin, for example, the following general formula (VII-1); as the naphthalene diol type epoxy resin, the following formula (VII-2); as the bifunctional or tetrafunctional epoxy type naphthalene resin, the following formula (VII-3): Examples of (VII-4) (VII-5) and naphthylene ether type epoxy resins can be represented by the following general formula (VII-6), and one or more of these can be used. Of these, naphthylene ether type epoxy resins are preferred from the viewpoint of low water absorption and low thermal expansion. The naphthylene ether type epoxy resin is an epoxy resin having a structure in which a naphthalene skeleton is bonded to another arylene structure via an oxygen atom.

(N represents an average of 1 to 6 and R represents a glycidyl group or a hydrocarbon group having 1 to 10 carbon atoms, provided that one of R is a glycidyl group.)

(In the formula, 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, an aralkyl group, a naphthalene group, or a glycidyl ether group-containing naphthalene. And o and m are each an integer of 0 to 2, and either o or m is 1 or more.)

As the naphthylene ether type epoxy resin, for example, those represented by the following formulas (6) and (7) may be used.

The arylalkylene type epoxy resin refers to an epoxy resin having one or more arylalkylene groups in a repeating unit, and examples thereof include a xylylene type epoxy resin and a biphenyldimethylene type epoxy resin. Any one or more of these can be used. Among these, the aryl alkylene 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 number of repeating units “n” of the biphenyldimethylene type epoxy resin represented by the formula (II) is not particularly limited, but is preferably 1 to 10, and more preferably 2 to 5. When the average number of repeating units “n” is less than the lower limit, the biphenyldimethylene type epoxy resin is easily crystallized, so that the solubility in a general-purpose solvent decreases. For this reason, the varnish of the first resin composition may be difficult to handle. On the other hand, when the average number of repeating units “n” exceeds the upper limit, depending on the solvent used, the viscosity of the varnish of the first resin composition may increase. In this case, the fiber base material 2 cannot be sufficiently impregnated with the first resin composition, and as a result, molding failure of the prepreg 1 and mechanical strength may be reduced.

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 in the entire resin composition. If the content is too small, the reactivity of the cyanate resin may decrease, or the moisture resistance of the resulting product may decrease. Although the upper limit of content of an epoxy resin is not specifically limited, 40 weight% or less is preferable. If the content is too large, the heat resistance may decrease.

The lower limit of the weight average molecular weight (Mw) of the epoxy resin is not particularly limited, but is preferably 500 or more, more preferably 800 or more. If Mw is too small, tackiness may occur in the resin layer. The upper limit of Mw is not particularly limited, but is preferably Mw 20,000 or less, and particularly preferably Mw 15,000 or less. If Mw is too large, the impregnation property to the fiber base material may be deteriorated during the production of the insulating resin layer, and a uniform product may not be obtained. The Mw of the epoxy resin can be measured by GPC, for example.

Furthermore, you may add to a 1st resin composition the component (a resin etc. are included) which improves adhesiveness with a metal. Examples of such components include thermoplastic resins such as phenoxy resins, polyvinyl acetal resins, and polyamide resins, and it is preferable to include any one or more of these. Among these resins, it is preferable to include a phenoxy resin from the viewpoint of adhesion to a metal.
Furthermore, the first resin composition preferably contains a coupling agent.

Examples of the phenoxy resin include a phenoxy resin having a bisphenol skeleton, a phenoxy resin having a naphthalene skeleton, and a phenoxy resin having a biphenyl skeleton. A phenoxy resin having a structure having a plurality of these skeletons can also be used. Any one or more of these may be used as the phenoxy resin.

Among these, it is preferable to use a phenoxy resin having a biphenyl skeleton and a bisphenol S skeleton as the phenoxy resin. Accordingly, the glass transition temperature of the phenoxy resin can be increased due to the rigidity of the biphenyl skeleton, and the adhesion of the phenoxy resin to the metal can be improved due to 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 of the wiring part (metal) to the first resin layer 3 can be improved when a multilayer substrate is manufactured.

It is also preferable to use a phenoxy resin having a bisphenol A skeleton and a bisphenol F skeleton as the phenoxy resin. Thereby, the adhesiveness to the 1st resin layer 3 of a wiring part can further be improved at the time of manufacture of a multilayer substrate.

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

When the phenoxy resin is used, its content is not particularly limited, but it is preferably 1 to 40% by weight, more preferably 5 to 30% by weight of 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 polyvinyl formal and polyvinyl butyral. Any one or more of these can be used. The degree of acetalization of the polyvinyl acetal resin is preferably 40% or more from the viewpoint of water absorption and 80% or less from the viewpoint of compatibility.
Examples of the polyamide-based resin include aromatic polyamides from the viewpoint of heat resistance. Moreover, it is preferable that a weight average molecular weight of a polyamide-type resin is 15,000 or more from an adhesive viewpoint with a conductor layer.
Examples of the polyamide-based resin include phenolic hydroxyl group-containing aromatic polyamide-poly (butadiene-acrylonitrile) block copolymers (for example, trade name KAYAFLEX BPAM-155 (Nippon Kayaku, terminal is an amide group)).

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

As the coupling agent, it is preferable to use at least one selected from, for example, an epoxy silane coupling agent, a titanate coupling agent, an aminosilane coupling agent, and a silicone oil type coupling agent.

When the coupling agent is used, its content is not particularly limited, but it is preferably 0.05 to 3 parts by weight, more preferably 0.1 to 2 parts by weight with respect to 100 parts by weight of the inorganic filler. More preferred.

In addition to the components described above, the first resin composition can contain additives such as an antifoaming agent, a leveling agent, a pigment, and an antioxidant as necessary.

The second resin composition has a composition different from that of the first resin composition. Specifically, the second resin layer 4 has a better embedding property than the first resin layer 3 and further has a composition satisfying the above-described physical properties. Has been.

The constituents of the second resin composition can be the same as those mentioned in the first resin composition, but the type and content of the resin and filler, the molecular weight of the resin (average number of repeating units) ) Etc. are different. As a result, the second resin layer 4 has different characteristics from the first resin layer 3.
The 2nd resin composition contains the thermoplastic resin mentioned above, a thermosetting resin, an inorganic filler, a hardening accelerator etc., for example. The second resin composition includes, for example, the above-described epoxy resin, cyanate resin, and inorganic filler. As the epoxy resin, an epoxy resin having the above-described naphthalene skeleton and a structure in which the naphthalene skeleton is bonded to another arylene structure via an oxygen atom is preferable.
Here, the inorganic filler contained in the second resin layer 4 is preferably spherical fused silica having an average particle diameter of 5.0 μm or less, and preferably has an average particle diameter of 0.01 to 2.0 μm, particularly an average particle diameter of 10 to 50 nm. Spherical fused silica is more preferred. The heat resistance of the prepreg 1 can be improved by using such silica (nanosilica) having an average particle size of 50 nm or less.
When silica having an average particle size of 50 nm or less is used, it is known that the silica is dispersed in the strands of the fiber base 2 and the resin component also penetrates into the strands. Thereby, it can suppress that a space | gap will be formed in the strand of the fiber base material 2 of the prepreg 1, and the heat resistance of the prepreg 1 can be improved.
The second resin composition preferably contains silica having an average particle diameter of 0.5 to 5 μm in addition to the silica having a particle diameter of 50 nm or less.
On the other hand, the first resin composition preferably uses silica having an average particle size of 0.5 μm to 50 nm in order to form fine irregularities and improve the adhesion to the conductor circuit layer.

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. By doing in this way, the embedding property of the circuit of the 2nd resin layer 4 can be improved. On the other hand, the adhesiveness of the conductor circuit in the 1st resin layer 3 can be made favorable. Specifically, the content of the thermoplastic resin in the second resin layer 4 is preferably 10% by weight or less, more 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 include a thermoplastic resin.

<Method for producing prepreg>
The prepreg 1 as described above can be manufactured as follows using the manufacturing apparatus shown in FIG.
As shown in FIG. 3, the manufacturing apparatus 6 includes rollers 621 to 628, a nozzle (a die coater that is a discharge means) 611, and a drying device 64.

The roller 621 is a means for sending out a first resin sheet 3 ′ to be the first resin layer 3. The roller 621 includes a first resin sheet 3 ′ with a support 51 (in FIG. 3, the support 51 and the first resin sheet 3 '). A sheet composed of one resin sheet 3 ′ is referred to as a sheet 5). The roller 621 is configured to rotate by a motor (drive source) (not shown). When the roller 621 rotates, the sheet 5 including the first resin sheet 3 ′ is sent out from the roller 621.
In addition, as the support body 51, metal foil (metal layer), a resin film, etc. are mentioned, for example, Among these, metal foil is preferable. A metal foil is a part processed into a wiring part (circuit) etc., for example. Examples of the metal material constituting the metal foil include copper or a copper-based alloy, aluminum or an aluminum-based alloy, iron or an iron-based alloy, and stainless steel. And among these, as a metal material which comprises metal foil, it is excellent in electroconductivity, the circuit formation by an etching is easy, and since it is cheap, copper or a copper-type alloy is preferable.
Further, the minimum melt viscosity at 50 to 150 ° C. of the first resin sheet 3 ′ is 1000 Pa · s or more and 25000 Pa · s or less.
As described above, when the minimum 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 fiber substrate 2. Moreover, it becomes difficult to mix with the second resin layer 4. By setting the minimum melt viscosity at 50 to 150 ° C. to 25000 Pa · s or less, adhesion to the fiber base material 2 can be secured. The measuring method is as described above.

Further, the roller 623 is a means for feeding out the fiber base material 2, and the fiber base material 2 is wound around the roller 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 sent out from the roller 623.

Further, the roller 622 is a means for regulating the moving direction of the sheet 5, and is installed at the subsequent stage of the roller 621.

Further, the roller 624 is a means for regulating the moving direction of the fiber base material 2 and is installed at the rear stage of the roller 622.

The roller 625 is a means for bonding the first resin sheet 3 ′ and the fiber base material 2, and is installed at the subsequent stage of the

rollers

622 and 624.
The first resin sheet 3 ′ is conveyed along the outer peripheral surface of the roller 625 so as to contact the outer peripheral surface. At this time, the first resin sheet 3 ′ is in surface contact with the quarter of the circumference of the roller 625 through the support 51.
Further, the fiber base material 2 is also conveyed along the outer peripheral surface of the roller 625 so as to contact the outer peripheral surface. The fiber base 2 comes into contact with the roller 625 through the first resin sheet 3 ′ where the roller 625 is in indirect contact with the first resin sheet 3 ′. The fiber base material 2 is conveyed along the outer peripheral surface of the roller 625 so as to contact the outer peripheral surface. However, the contact area between the fiber base 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 2 and the first resin sheet 3 ′ are pulled in the transport direction, and tension is applied to them. By doing in this way, the 1st resin sheet 3 'and the fiber base material 2 can be crimped | bonded using the outer peripheral surface of the roller 625. FIG.
Thus, by using the roller 625 and press-bonding the fiber base 2 and the first resin sheet 3 ′, it is possible to prevent the fiber base 2 from being excessively impregnated with the first resin sheet 3 ′. .
The

rollers

626 and 627 are means for regulating the moving direction of the sheet 5 including the first resin sheet 3 ′, the fiber base 2, and the second resin layer 4 on the fiber base 2. They are installed in the order after 625.

The roller 628 is a means for winding the prepreg 1. The roller 628 is configured to rotate by a motor (not shown). When the roller 628 rotates, the prepreg 1 is wound around the roller 628.

The nozzle 611 discharges (supplies) a liquid (varnish-like) second resin composition at normal temperature (25 ° C.) on the surface of the fiber base 2 opposite to the first resin layer 3 (for example, Die coater). The term “liquid” is not limited to liquid but is a concept that includes fluidity.

The drying device 64 is installed between the nozzle 611 and the roller 626. As the drying device 64, in this embodiment, a device that performs drying while horizontally conveying an object is used. Thereby, the tension | tensile_strength added to the fiber base material 2 can be made comparatively small, and an internal distortion can be prevented or suppressed.

(First step)
As shown in FIG. 3, the roller 621 of the manufacturing apparatus 6 is rotated, the sheet 5 including the first resin sheet 3 ′ is continuously sent out from the roller 621, and the roller 623 is rotated so that the fiber from the roller 623 The substrate 2 is fed out (supplied continuously), the roller 628 is rotated, and the prepreg 1 is wound around the roller 628.

The first resin sheet 3 ′ is in the B stage state.
Next, in the roller 625, the first resin sheet 3 ′ and the fiber base material 2 are pressure-bonded.

The angle (bonding angle) θ between the first resin sheet 3 ′ and the fiber base material 2 at this time is preferably an acute angle. Thereby, it can prevent or suppress that distortion arises in the fiber base material 2. FIG.

Moreover, it is preferable that the tension | tensile_strength by the side of the fiber base material 2 is smaller than the tension | tensile_strength by 1st resin sheet 3 'side. Specifically, the tension on the fiber base 2 side is preferably 30 N or less, and more preferably about 15 to 25 N. Thereby, the dimensional change and internal distortion of the fiber base material 2 can be prevented or suppressed.
In addition, as shown in FIG. 2, when impregnating the 1st resin layer 3 to the fiber base material 2, the tension | tensile_strength of 1st resin sheet 3 'is adjusted and a 1st resin layer is made into the fiber base material 2. As shown in FIG. Can be impregnated.

(Second step)
Next, 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 2 opposite to the first resin sheet 3 ′.

(Third step (drying step))
Next, the varnish containing 1st resin sheet 3 'and 2nd resin composition is heat-dried with the drying apparatus 64. FIG. Thereby, the prepreg 1 is obtained. The prepreg 1 is wound around a roller 628.
In addition, as shown in FIG. 2, when impregnating the 1st resin layer in the fiber base material 2, the 1st resin layer can be impregnated in the fiber base material 2 also in this drying process.

The drying conditions are not particularly limited, and are appropriately set according to the composition of the first resin composition and the second resin composition (particularly the composition of the second resin composition) and various conditions, but the second resin composition It is preferable to set the volatile component in the product to be 1.5 wt% or less with respect to the resin, and it is more preferable to set it to be about 0.8 to 1.0 wt%. Specifically, the drying temperature is preferably 100 to 150 ° C., more preferably about 100 to 130 ° C. The drying time is preferably about 2 to 10 minutes, more preferably about 2 to 5 minutes.

In the present embodiment, the first resin sheet 3 ′ is pressure-bonded to the fiber base 2, while the varnish containing the second resin composition is supplied to the fiber base 2 when forming the second resin layer 4. ing. Thereby, the interface between the 1st resin layer 3 and the 2nd resin layer 4 can be formed reliably.
Furthermore, in this embodiment, since the varnish containing a 2nd resin composition is supplied to the fiber base material 2, it is easy to make the fiber base material 2 impregnate a 2nd resin composition. On the other hand, 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 shape. It has become. Thereby, the prepreg 1 which the 2nd resin layer 4 impregnated the fiber base material 2 over the position of 90% of the thickness of the fiber base material 2 can be manufactured easily.

In the present embodiment, the prepreg 1 is manufactured by using the manufacturing apparatus 6 shown in FIG. 3, but the prepreg 1 can also be manufactured by using the manufacturing apparatus 6a shown in FIG.
The manufacturing apparatus 6 a does not include the nozzle 611 of the manufacturing apparatus 6 but includes a bonding apparatus 65 and a roller 629. The other points are the same as the manufacturing apparatus 6.

The laminating device 65 is installed between the roller 627 and the roller 628. The laminating device 65 has a pair of

rollers

651 and 652 arranged opposite to each other and a heating unit (not shown) that heats the

rollers

651 and 652, and sandwiches an object between the

rollers

651 and 652, The object is configured to be pressurized and heated.

The roller 629 is installed in the front stage of the bonding apparatus 65. The roller 629 is a means for feeding an object, and a sheet 7 described later is wound around the roller 629. The roller 629 is configured to be rotated by a motor (not shown). When the roller 629 rotates, the sheet 7 is continuously fed out from the roller 629.

In the drying device 64, the fiber base 2 and the first resin sheet 3 ′ are heated, and the first resin sheet 3 ′ is melted.
In addition, when not impregnating the fiber base material 2 with the 1st resin layer 3 like FIG. 1, the drying apparatus 64 does not need to be.
The roller 629 of the manufacturing apparatus 6a is rotated, and the sheet 7 is sent out from the roller 629. As shown in FIG. 4, the sheet 7 includes a resin film 8 and a second resin sheet 4 ′ provided on one surface of the resin film 8 and made of a solid or semi-solid second resin composition. Have. The second resin sheet 4 ′ is in a B stage state.
The minimum melt viscosity (η2) at 50 to 150 ° C. of the second resin sheet 4 ′ is lower than the minimum melt viscosity (η1) at 50 to 150 ° C. of the first resin sheet 3 ′. By doing so, the second resin sheet 4 ′ can be easily impregnated into the fiber base material 2, and the second resin layer 4 can be impregnated up to 90% or more of the thickness of the fiber material 2.
Further, by setting the minimum melt viscosity ratio η1 / η2 to 1.1 or more, the first resin layer 3 and the second resin layer 4 are not mixed, and the interface between the first resin layer 3 and the second resin layer 4 is achieved. Can be formed.
Moreover, there exists an effect of improving the adhesiveness of an interface by making minimum melt viscosity ratio (eta) 1 / (eta) 2 into 100 or less, especially 80 or less.
Specifically, the lowest melt viscosity (η1) of the first resin sheet 3 ′ is preferably 1000 Pa · s or more and 25000 Pa · s or less.
On the other hand, the minimum melt viscosity (η2) of the second resin sheet 4 ′ is preferably 50 Pa · s or more and 10000 Pa · s or less, more preferably 5000 Pa · s or less, and further 3000 Pa · s or less. Is desirable. The measuring method is as described above.

As the resin film 8, the same film as that described as the resin film of the support 51 can be used.

In this step, the sheet 7 and the sheet 5 that is a laminate of the fiber base material 2 and the support 51 pass between the roller 651 and the roller 652 of the laminating device 65, The laminated body of the fiber base material 2 and the support 51 is pressurized and heated by the laminating device 65. Thereby, the sheet | seat 7 is crimped | bonded to the surface on the opposite side to the 1st resin layer 3 of the fiber base material 2 via 2nd resin sheet 4 ', and the prepreg 1 which is a lamination sheet is obtained. The prepreg 1 is wound around a roller 628.

The conditions at the time of the pressure bonding are not particularly limited, and are appropriately set according to the composition and various conditions of the second resin composition of the second resin layer 4, but the pressure is 0.1 to 1.0 MPa / cm. preferably ² mm, more preferably 0.3 ~ 0.5 MPa / cm ^{2 or} so. The heating temperature is preferably 100 to 130 ° C.
The first resin sheet 3 ′ and the second resin sheet 4 ′ are melted by heating at the time of the pressure bonding, but by keeping the minimum melt viscosity of the second resin layer 4 lower than that of the first resin layer 3, The second resin layer 4 can be impregnated into the fiber substrate 2. Further, as described above, the minimum melt viscosity ratio η1 / η2 between the first resin layer 3 and the second resin layer 4 is set to 1.1 or more, so that the first resin layer 3 and the second resin layer 4 An interface can be formed between them.

<Board>
Next, the substrate of the present invention will be described with reference to FIG. A substrate 10 shown in FIG. 5 includes a laminate 11 and metal layers 12 provided on both surfaces of the laminate 11.

The laminated body 11 includes two prepregs 1 arranged with the second resin layers 4 facing each other, and an inner layer circuit board 13 sandwiched between the second resin layers 4.
The resin layers 3 and 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 securely embedded in the second resin layer 4.

The metal layer 12 is a part that is processed into a wiring part, for example, by bonding a metal foil such as a copper foil or an aluminum foil to the laminate 11, or plating copper or aluminum on the surface of the laminate 11. It is formed. Moreover, the support body 51 mentioned above can also be used as the metal layer 12.

The peel strength between 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 connection reliability in the semiconductor device 100 (refer FIG. 6) obtained by processing the metal layer 12 into a wiring part can be improved more.

Such a substrate 10 is prepared by preparing two prepregs 1 in which a metal layer 12 is formed on the first resin layer 3 and sandwiching the inner layer circuit board 13 between these prepregs 1, for example, in a vacuum press, normal pressure, etc. A laminator and a method of laminating using a laminator that is heated and pressurized under vacuum are exemplified. The vacuum press can be performed with a normal hot press machine or the like sandwiched between flat plates. For example, a vacuum press manufactured by Meiki Seisakusho Co., Ltd., a vacuum press manufactured by Kitagawa Seiki Co., Ltd., a vacuum press manufactured by Mikado Technos, etc. Further, as a laminator apparatus, a commercially available vacuum laminating machine such as a vacuum applicator manufactured by Nichigo Morton, a vacuum pressure laminator manufactured by Meiki Seisakusho, a vacuum roll type dry coater manufactured by Hitachi Techno Engineering, or the like It can be manufactured using a belt press or the like.

The substrate 10 of the present invention may include a laminate in which the inner circuit board 13 is omitted and the two prepregs 1 are directly bonded to each other, and the metal layer 12 is omitted. It may be what was done.

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

A semiconductor device 100 shown in FIG. 6 connects a bump 501 to the 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. Thus, the semiconductor element 500 mounted on the multilayer substrate 200 is provided. In addition, a wiring part, a pad part, a solder ball, and 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 and 1e provided on the lower side of the substrate 10. 1f. The prepregs 1a to 1f are the same as the prepreg 1. The prepregs 1a to 1c are arranged so that the second resin layer 4 is located on the substrate 10 side, that is, in order of the second resin layer 4, the fiber base material 2, and the first resin layer 3 from the substrate 10 side. The prepreg 1 is disposed. On the other hand, the prepregs 1d to 1f are arranged such that the second resin layer 4 is positioned on the substrate 10 side, that is, the second resin layer 4, the fiber base material 2, and the first resin layer 3 are in this order. Is arranged.
In the multilayer substrate 200, the resin layers 3 and 4 of the prepreg 1 are completely cured.

The multilayer substrate 200 includes a circuit unit 201a provided between the prepreg 1a and the prepreg 1b, a circuit unit 201b provided between the prepreg 1b and the prepreg 1c, and a prepreg 1d and the prepreg 1e. The circuit portion 201d is provided, and the circuit portion 201e is provided between the prepreg 1e and the prepreg 1f. Each of the circuit portions 201 a to 201 e is embedded with the second resin layer 4.

Furthermore, the multilayer substrate 200 has holes provided through the respective prepregs 1a to 1f, and in the holes, conductors that electrically connect adjacent circuit parts or circuit parts and pad parts. A portion 202 is formed.

Each metal layer 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.

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

It should be noted that the present invention is not limited to the above-described embodiment, and modifications, improvements, and the like within the scope that can achieve the object of the present invention are included in the present invention.
As described above, the prepreg, the substrate, and the semiconductor device of the present invention have been described with respect to the illustrated embodiment. However, the present invention is not limited to this, and the respective parts constituting the prepreg, the substrate, and the semiconductor device have the same functions. It can be replaced with any configuration that can be exhibited. Moreover, arbitrary components may be added.

<Appendix>
(Appendix 1)
A fiber substrate;
A first resin layer that covers one surface side of the fiber substrate and is composed of a first resin composition;
Covering the other surface side of the fiber substrate, and comprising a second resin layer composed of a second resin composition different from the first resin composition,
A prepreg in which the first resin layer and the second resin layer are in contact with each other to form an interface.
(Appendix 2)
In the prepreg described in Appendix 1,
The first resin layer is a layer for providing a metal layer on the upper surface thereof,
The second resin layer is a prepreg that is a layer for embedding a circuit.
(Appendix 3)
In the prepreg according to

appendix

1 or 2,
The prepreg in which the second resin layer is impregnated in the fiber substrate over at least a region between the other surface of the fiber substrate and the center of the thickness of the fiber substrate.
(Appendix 4)
In the prepreg described in appendix 3,
The second resin layer is a prepreg impregnated in the fiber base material from at least the other surface of the fiber base material to a position of 90% of the thickness of the fiber base material.
(Appendix 5)
In the prepreg described in appendix 4,
The second resin layer is impregnated in the fiber base material,
The interface between the first resin layer and the second resin layer is a prepreg located outside the fiber substrate.
(Appendix 6)
In the prepreg according to any one of appendices 1 to 5,
The prepreg in which the content of the thermoplastic resin in the first resin layer is larger than the content of the thermoplastic resin in the second resin layer.
(Appendix 7)
In the prepreg according to any one of appendices 1 to 6,
90 ° peel strength A after superposing the first resin layer of the prepreg on copper foil and heat-treating under conditions of load 2 MPa, temperature 220 ° C., 1 hour,
A prepreg higher than 90 ° peel strength B after the second resin layer of the prepreg is superposed on a copper foil and heat-treated under the conditions of a load of 2 MPa, a temperature of 220 ° C. and 1 hour.
(Appendix 8)
In the prepreg according to any one of appendices 1 to 7,
According to IPC-TM-650 Method 2.3.17, the resin flow measured by heating and pressurizing for 5 minutes under the conditions of 171 ± 3 ° C. and 1380 ± 70 kPa is 15 wt% or more and 50 wt% or less,
When the prepreg is sandwiched between a pair of opposing rubber plates and heated and pressurized under the conditions of 120 ° C. and 2.5 MPa, the first resin layer protruding from the outer edge of the fiber substrate in plan view and the The total weight of the second resin layer is 5% or less with respect to the total weight of the entire first resin layer and the entire second resin layer, and the rubber plate satisfies the following (i) to (iii): .
(I) Rubber hardness measured in accordance with JIS K 6253 A is 60 °
(Ii) Thickness 3mm
(Iii) Material is silicon (Appendix 9)
In the prepreg according to any one of appendices 1 to 8,
The first resin layer includes a thermoplastic resin,
The thermoplastic resin is a prepreg containing at least one of a phenoxy resin, a polyvinyl alcohol resin, and a polyamide resin.
(Appendix 10)
The prepreg according to any one of appendices 1 to 9, wherein the second resin layer includes an epoxy resin, a cyanate resin, and an inorganic filler.
(Appendix 11)
In the prepreg according to any one of appendices 1 to 10,
The first resin layer and the second resin layer have a naphthalene skeleton, and the prepreg includes an epoxy resin having a structure in which the naphthalene skeleton is bonded to another arylene structure through an oxygen atom.
(Appendix 12)
The prepreg according to any one of appendices 1 to 11, wherein the prepreg causes the first resin layer to abut the first resin sheet serving as the first resin layer against one surface of the fiber base material. ,
A prepreg produced by impregnating a second resin sheet serving as a second resin layer or a liquid composition containing the second resin composition from the other surface side of the fiber substrate.
(Appendix 13)
In the prepreg according to any one of appendices 1 to 12,
Ratio η1 / of the lowest melt viscosity η1 of the first resin layer and the lowest melt viscosity η2 of the second resin layer in the range of 50 ° C. to 150 ° C. when the temperature is raised from 25 ° C. at a rate of 3 ° C./min. A prepreg having η2 of 1.1 times or more and 100 times or less.
(Appendix 14)
In the prepreg according to any one of appendices 1 to 13,
The second resin layer is a prepreg containing silica having a particle size of 50 nm or less.
(Appendix 15)
In the prepreg described in appendix 14,
The fiber base material is a glass cloth,
A prepreg in which the silica is present in the strand of the glass cloth.
(Appendix 16)
A substrate having the prepreg according to any one of appendices 1 to 15,
With a circuit layer,
The circuit layer is embedded by the two resin layers of the prepreg,
A substrate in which a metal layer is provided on the first resin layer of the prepreg.
(Appendix 17)
The substrate according to appendix 16, and
A semiconductor device comprising: a semiconductor element mounted on the substrate.

(Appendix 18)
Providing a first resin layer made of the first resin composition by pressure-bonding the first resin sheet to one surface of the fiber base;
Forming a second resin layer made of a second resin composition different from the first resin composition on the other surface side of the fiber substrate,
In the step of forming the second resin layer,
The manufacturing method of the prepreg which forms the 2nd resin layer which impregnated the said fiber base material over 90% of the thickness of the said fiber base material from the other surface of the said fiber base material at least.
(Appendix 19)
In the method for producing a prepreg according to appendix 18,
The method for producing a prepreg, wherein the first resin sheet has a minimum melt viscosity at 50 to 150 ° C. of 1000 Pa · s or more and 25000 Pa · s or less.
(Appendix 20)
In the method for producing a prepreg according to appendix 18 or 19,
In the step of forming the second resin layer,
The manufacturing method of the prepreg which supplies a liquid 2nd resin composition to the other surface side of the said fiber base material.
(Appendix 21)
In the method for producing a prepreg according to appendix 18 or 19,
In the step of forming the second resin layer,
Supplying the second resin sheet to be the second resin layer to the other surface side of the fiber substrate, heating the second resin sheet, and impregnating the fiber substrate;
Ratio η1 / of minimum melt viscosity η1 of the first resin sheet and minimum melt viscosity η2 of the second resin sheet in the range of 50 ° C. to 150 ° C. when the temperature is increased from 25 ° C. at a rate of 3 ° C./min. The manufacturing method of the prepreg whose (eta) 2 is 1.1 times or more and 100 times or less.
(Appendix 22)
In the method for producing a prepreg according to any one of appendices 18 to 21,
In the step of pressure-bonding the first resin sheet to one surface of the fiber base material,
Conveying the first resin sheet continuously along the outer peripheral surface of the laminate roll so that the first resin sheet is in direct or indirect surface contact with the laminate roll,
The fiber base material is continuously conveyed toward the laminating roll so as to come into contact with the laminating roll via the first resin sheet at a position where the laminating roll and the first resin sheet are in contact with each other. A method for manufacturing a prepreg.
(Appendix 23)
In the method for producing a prepreg according to any one of appendices 18 to 22,
The first resin sheet is wound in a roll shape, and the first resin sheet is delivered from the roll, and the first resin sheet is sent out in the step of pressure-bonding the first resin sheet to one surface of the fiber base material. A method for producing a prepreg, wherein the first resin sheet is pressure-bonded to one surface of a fiber base material.
(Appendix 24)
In the method for producing a prepreg according to any one of appendices 18 to 23,
The first resin sheet is formed on a support,
In the step of pressure-bonding the first resin sheet to one surface of the fiber base material, a prepreg manufacturing method in which the first resin sheet on the support is pressure-bonded to one surface of the fiber base material.

Next, examples of the present invention will be described.
(Example 1)
(First resin composition)
A first resin composition of A-1 in Table 1 was prepared.
First, naphthalene type epoxy resin (Nippon Kayaku Co., Ltd., trade name NC-7300) 12.2 parts by weight, naphthalene type epoxy resin (DIC, trade name HP 4700) 5 parts by weight, phenol novolac type cyanate resin (Lonza) Product name: PT-30) 17.2 parts by weight Biphenyl type phenoxy resin (Mitsubishi Chemical Co., Ltd., trade name YX-6654BH30) 15 parts by weight (in terms of solid content), 1-benzyl-2-methylimidazole as a curing agent ( 0.4 parts by weight of Shikoku Kasei Co., Ltd., Curazole 1B2PZ) was dissolved in methyl ethyl ketone. Furthermore, as an inorganic filler, 50 parts by weight of spherical silica (trade name SFP-20M, average particle size 0.3 μm, manufactured by Denki Kagaku Kogyo Co., Ltd.), epoxy silane coupling agent (trade name KBM-403E, manufactured by Shin-Etsu Chemical Co., Ltd.) ) Was added in an amount of 0.2 part by weight and stirred for 60 minutes using a high-speed stirrer. As a result, a varnish of 70% by weight of the resin composition was prepared.
Next, a polyethylene terephthalate film (manufactured by Unitika, thickness 38 μm, width 560 mm) is used as a carrier film, and the varnish is applied with a comma coater and dried at 170 ° C. for 3 minutes with a drying device, thickness 5 μm, width 540 mm. The 1st resin sheet (layer used as the 1st resin layer) was formed.
The average particle size of silica is determined by measuring the particle size distribution of silica on a volume basis with a dynamic light scattering particle size distribution analyzer (LB-550, manufactured by HORIBA) by dispersing silica in water with ultrasonic waves. The median diameter was defined as the average particle diameter. Specifically, the average particle size is defined by the volume cumulative particle diameter d _50. The same applies to the following examples and comparative examples.

(Second resin composition)
A second resin composition having the composition shown in B-1 of Table 2 was prepared. 9 parts by weight of a naphthalene ether type epoxy resin (manufactured by DIC, trade name HP-6000), 6 parts by weight of a biphenyl aralkyl type phenol resin (trade name NC-3000, manufactured by Nippon Kayaku Co., Ltd.), a phenol novolac type cyanate resin (manufactured by Lonza) 15.5 parts by weight of trade name PT-30) was dissolved in methyl ethyl ketone. Furthermore, as inorganic fillers, 66 parts by weight of spherical silica (manufactured by Admatechs, SO-31R average particle size 1.0 μm) and 3 parts by weight of spherical silica (manufactured by Admatechs, trade name Admanano average particle size 50 nm) Then, 0.5 part by weight of an epoxy silane coupling agent (trade name KBM-403E, manufactured by Shin-Etsu Chemical Co., Ltd.) was added, and the mixture was stirred for 60 minutes using a high-speed stirrer. As a result, a varnish of 70% by weight of the resin composition was prepared.

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

(Example 2)
(First resin composition)
A first resin composition of A-2 in Table 1 was prepared.
First, 12.2 parts by weight of a naphthalene-modified cresol novolak epoxy resin (manufactured by DIC, trade name HP-5000), 5 parts by weight of a naphthalene-type epoxy resin (manufactured by DIC, trade name HP 4700), a phenol novolac-type cyanate resin (Lonza) Product name: PT-30) 17.2 parts by weight Biphenyl type phenoxy resin (Mitsubishi Chemical Co., Ltd., trade name YX-6654BH30) 15 parts by weight (in terms of solid content), 1-benzyl-2-methylimidazole as a curing agent ( 0.4 parts by weight of Shikoku Kasei Co., Ltd., Curazole 1B2PZ) was dissolved in methyl ethyl ketone. Furthermore, as an inorganic filler, 50 parts by weight of spherical fused silica (trade name SFP-20M, average particle size 0.3 μm, manufactured by Denki Kagaku Kogyo Co., Ltd.), epoxy silane coupling agent (trade name KBM-, manufactured by Shin-Etsu Chemical Co., Ltd.) 403E) was added by 0.2 parts by weight, and the mixture was stirred for 60 minutes using a high-speed stirrer. As a result, a varnish of 70% by weight of the resin composition was prepared.
Next, a polyethylene terephthalate film (manufactured by Unitika, thickness 38 μm, width 560 mm) is used as a carrier film, and the varnish is applied with a comma coater and dried at 170 ° C. for 3 minutes with a drying device, thickness 5 μm, width 540 mm. The 1st resin sheet (layer used as the 1st resin layer) was formed.

(Second resin composition)
As the 2nd resin composition, the same thing as Example 1 was prepared.
(Manufacture of prepreg)
A prepreg was produced in the same manner as in Example 1, using the resin layer with a polyethylene terephthalate film and a varnish containing the second resin composition.

(Example 3)
(First resin composition)
A first resin composition A-3 in Table 1 was prepared.
First, 16.2 parts by weight of naphthalene-modified cresol novolac epoxy resin (DIC, trade name HP-5000), 9 parts by weight of naphthalene type epoxy resin (DIC, trade name HP 4700), phenol novolac cyanate resin (Lonza) Product name PT-30) 24.2 parts by weight, rubber-modified phenol OH-containing polyamide resin (Nippon Kayaku Co., Ltd., trade name BPAM-155, Mw = 15,000 or more) 15 parts by weight, 1 as a curing agent -0.4 parts by weight of benzyl-2-methylimidazole (manufactured by Shikoku Kasei Co., Ltd., Curesol 1B2PZ) was dissolved in methyl ethyl ketone. Further, as an inorganic filler, 35 parts by weight of spherical fused silica (trade name SFP-20M, average particle size 0.3 μm, manufactured by Denki Kagaku Kogyo Co., Ltd.), epoxy silane coupling agent (trade name KBM-, manufactured by Shin-Etsu Chemical Co., Ltd.) Then, 0.2 part by weight of 403E) was added and stirred for 60 minutes using a high-speed stirrer. As a result, a varnish of 70% by weight of the resin composition was prepared.
Next, a polyethylene terephthalate film (manufactured by Unitika, thickness 38 μm, width 560 mm) is used as a carrier film, and the varnish is applied with a comma coater and dried at 170 ° C. for 3 minutes with a drying device, thickness 5 μm, width 540 mm. The 1st resin sheet (layer used as the 1st resin layer) was formed.
(Second resin composition)
As the 2nd resin composition, the same thing as Example 1 was prepared.
(Manufacture of prepreg)
A prepreg was produced in the same manner as in Example 1, using the resin layer with a polyethylene terephthalate film and a varnish containing the second resin composition.

(Example 4)
(First resin composition)
The same 1st resin composition as Example 3 was created, and the same resin layer with a polyethylene terephthalate film as Example 1 was used.
(Second resin composition)
A second resin composition having the composition shown in B-2 of Table 2 was prepared.
9 parts by weight of dicyclopentadiene type epoxy resin (made by DIC, trade name HP-7200L), 6 parts by weight of biphenyl aralkyl type phenol resin (trade name GPH-65 made by Nippon Kayaku Co., Ltd.), phenol novolac type cyanate resin (Lonza) 15.5 parts by weight of product name PT-30) was dissolved in methyl ethyl ketone. Further, as inorganic fillers, 66 parts by weight of spherical silica (manufactured by Admatechs, SO-31R average particle diameter 1.0 μm), 3 parts by weight of spherical fused silica (manufactured by Admatechs, trade name Admanano average particle diameter 50 nm) 0.5 parts by weight of an epoxy silane coupling agent (trade name KBM-403E, manufactured by Shin-Etsu Chemical Co., Ltd.) was added and stirred for 60 minutes using a high-speed stirrer. As a result, a varnish of 70% by weight of the resin composition was prepared.
(Manufacture of prepreg)
A prepreg was produced in the same manner as in Example 1 using the resin layer with a polyethylene terephthalate film and the varnish of the second resin composition.

(Example 5)
(First resin composition)
The same 1st resin composition as Example 3 was created, and the same resin layer with a polyethylene terephthalate film as Example 1 was used.
(Second resin composition)
A second resin composition having the composition shown in B-3 of Table 2 was prepared.
10 parts by weight of a naphthalene ether type epoxy resin (manufactured by DIC, trade name HP-6000), 8 parts by weight of a biphenyl aralkyl type phenol resin (trade name GPH-65, manufactured by Nippon Kayaku Co., Ltd.), a phenol novolac type cyanate resin (manufactured by Lonza) 14.5 parts by weight of a trade name PT-30) and 2 parts by weight (converted to a solid content) of a biphenyl type phenoxy resin (trade name YX-6654BH30, manufactured by Mitsubishi Chemical Corporation) were dissolved in methyl ethyl ketone. Furthermore, 65 parts by weight of spherical fused silica (manufactured by Admatechs, SO-31R average particle size 1.0 μm) and an epoxy silane coupling agent (manufactured by Shin-Etsu Chemical Co., Ltd., trade name KBM-403E) are used as inorganic fillers. 0.5 part by weight was added and stirred for 60 minutes using a high-speed stirrer. As a result, a varnish of 70% by weight of the resin composition was prepared.
(Manufacture of prepreg)
A prepreg was produced in the same manner as in Example 1 using the resin layer with a polyethylene terephthalate film and the varnish of the second resin composition.

(Example 6)
(First resin composition)
The same 1st resin composition as Example 3 was created, and the same resin layer with a polyethylene terephthalate film as Example 1 was used.
(Second resin composition)
A second resin composition having the composition shown in B-2 of Table 2 was prepared.
10 parts by weight of a dicyclopentadiene type epoxy resin (manufactured by DIC, trade name HP-7200L), 8 parts by weight of a biphenyl aralkyl type phenol resin (trade name GPH-65, manufactured by Nippon Kayaku Co., Ltd.), a phenol novolac type cyanate resin ( 14.5 parts by weight of Lonza Corporation, trade name PT-30) and 2 parts by weight of biphenyl type phenoxy resin (trade name YX-6654BH30, manufactured by Mitsubishi Chemical Corporation) (in terms of solid content) were dissolved in methyl ethyl ketone. Furthermore, 65 parts by weight of spherical fused silica (manufactured by Admatechs, SO-31R average particle size 1.0 μm) and an epoxy silane coupling agent (manufactured by Shin-Etsu Chemical Co., Ltd., trade name KBM-403E) are used as inorganic fillers. 0.5 part by weight was added and stirred for 60 minutes using a high-speed stirrer. As a result, a varnish of 70% by weight of the resin composition was prepared.
(Manufacture of prepreg)
A prepreg was produced in the same manner as in Example 1 using the resin layer with a polyethylene terephthalate film and the varnish of the second resin composition.

(Comparative Example 1)
A prepreg was produced using the varnish of the first resin composition having the composition of A-1 produced in Example 1 and the varnish of the second resin composition having the composition represented by B-1.
A die coater was used from both sides of the fiber base, and the varnish of the first resin composition was applied to one side, and the varnish of the second resin composition was applied to the other side, 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 manufactured by the method similar to Example 1 of the pamphlet of international publication WO2007 / 063960. Details are as follows.
1. Preparation of first resin layer varnish Cyanate resin (Lonza Japan, Primaset PT-30, weight average molecular weight about 2,600) 24% by weight, biphenyldimethylene type epoxy resin (manufactured by Nippon Kayaku Co., Ltd.) NC-3000, epoxy equivalent 275) 24% by weight, phenoxy resin is a copolymer of bisphenol A type epoxy resin and bisphenol F type epoxy resin, and the terminal part is a phenoxy resin having an epoxy group (Japan epoxy resin) 11.8% by weight, EP-4275, weight average molecular weight 60,000), 0.2 weight by weight of imidazole compound as a curing catalyst (“2-phenyl-4,5-dihydroxymethylimidazole” manufactured by Shikoku Chemicals) % Was dissolved in methyl ethyl ketone. Further, 39.8% by weight of spherical fused silica (manufactured by Admatechs, SO-25H, average particle size 0.5 μm) as an inorganic filler and epoxy silane type coupling agent (manufactured by Nihon Unicar, A-187) 0. 2% by weight was added and stirred for 60 minutes using a high-speed stirrer to prepare a resin varnish of 70% by weight of the resin composition (composition A-4 in Table 3).

2. Preparation of varnish of second resin layer 15% by weight of novolak-type cyanate resin (manufactured by Lonza Japan, Primaset PT-30, weight average molecular weight of about 2,600) as thermosetting resin, biphenyldimethylene type epoxy resin as epoxy resin (Nippon Kayaku Co., Ltd., NC-3000, epoxy equivalent 275) 8.7% by weight, phenol resin biphenyldimethylene type phenol resin (Nippon Kayaku Co., Ltd., GPH-65, hydroxyl equivalent 200) 6.3% by weight Was dissolved in methyl ethyl ketone. Further, spherical fused silica (manufactured by Admatechs, SO-25H, average particle size 0.5 μm) 69.7% by weight as an inorganic filler and epoxysilane type coupling agent (Nihon Unicar Co., Ltd., A-187) 0. 3% by weight was added, and the mixture was stirred for 60 minutes using a high-speed stirrer to prepare a varnish for the second resin layer of 70% by weight of the resin composition (composition B-5 in Table 3).

3. Production of carrier material A polyethylene terephthalate film (manufactured by Mitsubishi Chemical Polyester Co., Ltd., SFB-38, thickness 38 μmm, width 480 mm) was used as a carrier film. The carrier material I (finally the first resin layer is finally formed) is formed by drying for 3 minutes using a drying apparatus and forming a resin layer having a thickness of 9 μm and a width of 410 mm at the center in the width direction of the carrier film. Obtained.
Further, the amount of the varnish of the second resin layer to be coated by the same method is adjusted so that the resin layer having a thickness of 14 μm and a width of 360 mm is positioned at the center in the width direction of the carrier film. II (final formation of the second resin layer) was obtained.

4). Production of Prepreg Glass woven fabric (cross type # 1015, width 360 mm, thickness 15 μm, basis weight 17 g / m ² ) was used as a fiber substrate, and a prepreg was produced by a vacuum laminating apparatus and a hot air drying apparatus.
Specifically, the carrier material I and the carrier material II are overlapped on both surfaces of the glass woven fabric so as to be positioned at the center in the width direction of the glass woven fabric, respectively, and are laminated at 80 ° C. under a reduced pressure of 1330 Pa. Was used for bonding.
Here, in the inner region of the width direction dimension of the glass woven fabric, the resin layers of the carrier material I and the carrier material II are respectively bonded to both sides of the fiber cloth, and in the outer region of the width direction dimension of the glass woven fabric. The resin layers of carrier material I and carrier material II were joined together.
Next, the bonded material was heat-treated without applying pressure by passing it through a horizontal conveyance type hot-air drying apparatus set at 120 ° C. for 2 minutes to obtain a thickness of 30 μm (first resin layer: 5 μm, A prepreg having a fiber base material of 15 μm and a second resin layer of 10 μm was obtained.

(Evaluation methods)
The prepregs produced in the above-described examples and comparative examples were evaluated.

(Existence of interface)
The cross section perpendicular to the thickness direction of each prepreg is observed with an SEM (magnification 1000 times), and whether or not the interface between the first resin layer and the second resin layer can be confirmed. evaluated.
Table 4 shows the results, FIGS. 8 to 10 show SEM photographs of Examples 1, 5, and 6, and FIGS. 11 and 12 show SEM photographs of Comparative Examples 1 and 2, respectively.
In the prepregs of Examples 5 and 6, the region in which the first resin layer is in direct contact with the surface of the fiber base and the second resin layer protrude to the outside of the fiber base. There are areas that are not in contact with the substrate.

(Impregnation rate)
The cross section perpendicular to the thickness direction of each prepreg was observed with SEM (500 times magnification), and the average value B (measured at 10 points) from the surface of the glass cloth to the interface between the first resin layer and the second resin layer ) Was calculated. And the average value A (10 places measurement) of the thickness of a glass cloth was computed, and the impregnation rate was computed by B / Ax100 (%). The results are shown in Table 4. The thickness of the glass cloth is measured at the intersection of the warp and the weft.

(Performance of resin layer)
1. Peel strength The peel strength of the first resin layer and the second resin layer of each of the examples and comparative examples was measured. The measuring method is as follows.
The first resin layer 3 of the prepreg 1 was placed on a copper foil, and the 90 ° peel strength A after heat treatment in the atmosphere under the conditions of a load of 2 MPa, a temperature of 220 ° C. and 1 hour was measured. Further, the second resin layer 4 of the prepreg was placed on a copper foil, and the 90 ° peel strength B after heat treatment in the atmosphere under the conditions of a load of 2 MPa, a temperature of 220 ° C. and 1 hour was measured.
The peel strength was measured in accordance with JIS C 6481 90 degree peeling method by peeling the resin layer from the copper foil in the 90 degree direction. Specifically, at 25 ° C., the 90 ° peel strength when the resin layer was peeled off at a speed of 50 mm per minute was measured with a 90 ° peel tester.
The copper foil is a copper foil having a thickness of 2 μm (surface roughness Rz = 2.0 μm, trade name MT Ex-2 manufactured by Mitsui Kinzoku Kogyo Co., Ltd.). The results are shown in Table 4.
2. Embeddability An inner layer circuit board having a circuit pattern on the surface, a circuit thickness of 18 μm, and a remaining copper ratio of 50% was prepared. A prepreg was stacked so that the second resin layer was in contact with the circuit pattern of the inner layer circuit board, and pressure heating molding (1 MPa, 200 ° C., 90 minutes) was performed to obtain 10 substrates.
The cross section of each substrate was observed with a microscope. Then, the embedding property of the second resin layer was evaluated.
(Double-circle): It was excellent in the embedding property in all the board | substrates.
○: Microvoids occurred at the edge of the plate with virtually no problem.
X: Insufficient embedding and many voids occurred.
The results are shown in Table 4.

(Reliability between vias)
Eight prepregs obtained in Examples and Comparative Examples are stacked, and a copper foil having a thickness of 12 μm is stacked on both sides, and then heated and pressed at a pressure of 4 MPa and a temperature of 200 ° C. for 2 hours to have copper foils on both sides. A laminate was obtained. When the prepregs were stacked, the prepregs were stacked so that the first resin layer and the second resin layer were alternately arranged. Thereafter, a carbon dioxide laser is used to form a through hole having a diameter of 0.15 mm and a wall-to-wall distance of 100 μm by a conformal mask method. Thereafter, plating and circuit wiring are formed, under conditions of 130 ° C., 85% RH, and applied voltage of 20 V. And the insulation resistance was measured at 20V. N = 10 samples were prepared for measurement.
◎: All samples 1.0 × 10 ⁷ Ω or higher ○: 1.0 × 10 ⁷ Ω or more and consisting sample 8 or more, 9 fewer than ×: the sample to be 1.0 × 10 ⁷ Ω or more 8 Less than

(Minimum melt viscosity)
The measurement conditions for the minimum melt viscosity are as follows. The results are shown in Table 4.
In Examples and Comparative Examples, the lowest melt viscosities of the first resin layer and the second resin layer at 50 to 150 ° C. were measured. Here, the varnish of the first resin composition and the varnish of the second resin composition obtained in the respective Examples and Comparative Examples were applied with a comma coater device, dried at 170 ° C. for 3 minutes with a drying device, and a thickness of 5 μm. The film is a measurement object. However, the measurement result here corresponds to the minimum melt viscosity of the first resin layer and the second resin layer in the prepreg state.
The measurement conditions are as follows.
Dynamic viscoelasticity measuring device (manufactured by Anton Paar, device name Physica MCR-301)
Frequency: 62.83 rad / sec
Measurement temperature: 25-200 ° C, 3 ° C / min
Geometry: Parallel plate Plate diameter: 10mm
Plate spacing: 0.1mm
Load (normal force): 0N (constant)
Strain: 0.3%
Measurement atmosphere: Air

(Resin flow (wt%))
The measurement was performed according to IPC-TM-650 Method 2.3.17 using the prepregs of Examples and Comparative Examples. That is, as shown in FIG. 7, the prepregs of Examples and Comparative Examples were cut into 102 mm × 102 mm squares, four of them were stacked, and the weight (W ₀ (g)) was measured. A release film (product name: Sepanium 20M2C-S, manufacturer: Sun Aluminum Co., Ltd., size: 200 mm × 240 mm) was attached to both surfaces of the outermost layer of the prepreg (FIG. 7A). Thereafter, a prepreg was placed between the two SUS plates, heated and pressurized to 171 ° C. and 1.38 MPa, and hot plate pressed for 5 minutes (FIG. 7B). Next, the release film is peeled off, and the prepreg is cut out into a columnar shape having a diameter of 81 mm so that the stacking direction of the prepreg is in the height direction (FIG. 7C), and the weight (W ₂ ( g)) was measured. The resin flow was determined from equation (1). The results are shown in Table 3. In the formula (1),% is% by weight.

(Resin protrusion amount)
The prepregs of Examples and Comparative Examples cut to 200 mm × 200 mm were pressed using a hot press device of CVP300 manufactured by Nichigo-Morton Co., Ltd., and the amount of resin protrusion was measured. Specifically, the prepreg of the above example or comparative example is placed between two rubber plates sandwiched between two hot plates (SUS 1.5 mm) of this hot press apparatus, and the conditions are 120 ° C. and 2.5 MPa. And pressed for 60 seconds. The rubber plate was a silicon rubber having a rubber hardness measured according to JIS K 6253 A of 60 ° and a thickness of 3 mm. The results are shown in Table 4.

(Laminate thickness)
Eight prepregs obtained in Examples and Comparative Examples are stacked, and a copper foil having a thickness of 12 μm is stacked on both sides, and then heated and pressure-molded at a pressure of 3.5 MPa and a temperature of 200 ° C. for 2 hours. A laminated body having was obtained. In this laminate, the upper four prepregs have the first resin layer disposed on the upper copper foil side, and the other four prepregs have the first resin layer on the lower copper foil side. Is arranged.
Thereafter, all the copper foil was removed by etching with an etching solution (iron chloride), and the thickness of the diagonal line of the laminated plate (400 mm square) was measured at a pitch of 40 mm to calculate the maximum-minimum value. The results are shown in Table 4.
A: Less than 10 μm Δ: 10 μm or more and less than 30 μm ×: 30 μm or more

(Lamination of laminate)
Eight prepregs obtained in Examples and Comparative Examples are stacked, and a copper foil having a thickness of 12 μm is stacked on both sides, and then heated and pressure-molded at a pressure of 3.5 MPa and a temperature of 200 ° C. for 2 hours. A laminated body having was obtained. In this laminate, the upper four prepregs have the first resin layer disposed on the upper copper foil side, and the other four prepregs have the first resin layer on the lower copper foil side. Is arranged.
Thereafter, all the copper foil was removed by etching with an etching solution (iron chloride), and the warpage of a 50 mm square piece was measured. The results are shown in Table 4.
A: Less than 200 μm ×: 200 μm or more

(Heat-resistant)
Eight prepregs obtained in Examples and Comparative Examples are stacked, and a copper foil having a thickness of 12 μm is stacked on both sides, and then heated and pressure-molded at a pressure of 3.5 MPa and a temperature of 200 ° C. for 2 hours. A laminated body having was obtained. In this laminate, the upper four prepregs have the first resin layer disposed on the upper copper foil side, and the other four prepregs have the first resin layer on the lower copper foil side. Is arranged.
Next, heat treatment and moisture absorption treatment according to JEDEC standard level 2 were performed, and moisture absorption heat resistance reliability evaluation was performed. Specifically, the laminated body is pre-dried at 125 ° C./24 hours, then subjected to moisture absorption treatment at 85 ° C. and 60% 196 hours, and reflow for lead-free solder having a peak temperature of 260 ° C. The profile infrared reflow oven was passed 20 times. At each reflow, the appearance of the laminate was observed to confirm the presence or absence of swelling. Moreover, after passing through the infrared reflow furnace 10 times, the swelling inside the laminate was also investigated using SAT (ultrasonic imaging device). The results are shown in Table 4.
(Double-circle): There is no swelling of an external appearance after passing 20 times of reflow ovens. No swelling inside the laminate.
○: No swelling of the appearance after passing through the reflow furnace 20 times. There is swelling inside the laminate.
×: Appearance swelled after passing through the reflow furnace 1 to 5 times.

In Examples 1 to 6, since the second resin layer is impregnated into the fiber base material at least from the surface of the fiber base material to a position of 90% of the thickness of the fiber base material, What is necessary is just to comprise with a resin composition with high impregnation property, and the resin composition of a 1st resin layer is not restrict | limited to that with high impregnation property.
In Examples 1 to 6, since the second resin layer is impregnated into the fiber base material from at least the surface of the fiber base material to a position of 90% of the thickness of the fiber base material, the reliability between vias Is also good.
In Examples 1 to 6, it was confirmed that the first resin layer and the second resin layer were in contact with each other and an interface was present. Since the ratio η1 / η2 between the minimum melt viscosity η1 of the first resin layer and the minimum melt viscosity η2 of the second resin layer is 1.1 times or more, it is considered that a clear interface was formed. Moreover, it is thought that it became easy to impregnate the 2nd resin layer with respect to a fiber base material by making (eta) 1 / (eta) 2 1.1 times or more. In Examples 1 to 6, since η1 / η2 was 100 or less, the adhesion at the interface between the first resin layer and the second resin layer was excellent.
In Examples 1 to 6, the peel strength A of the first resin layer is 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 becomes the desired strength. I understand that. Furthermore, the embedding property of the circuit pattern is also good, and it can be seen that the first resin layer and the second resin layer can exhibit desired characteristics.
Further, it can be seen that the resin flow is 15% by weight or more, and the circuit embedding property is excellent. Further, the resin flow was 50% by weight or less, and the outflow of the resin during pressing could be suppressed.
Moreover, since the protrusion amount of resin is 5 weight% or less, the thickness uniformity of a laminated board is favorable and generation | occurrence | production of curvature is also suppressed.
In Examples 1 to 4, the heat resistance is very good because silica having an average particle diameter of 50 nm is used for the second resin layer.
Furthermore, in Examples 1 to 4, the reliability between vias is very high because silica having an average particle diameter of 50 nm is used for the second resin layer. It is considered that the reliability between vias is improved when nanosilica enters the fiber bundle and nanosilica adheres to the fiber.
Furthermore, the prepreg using the naphthylene ether type epoxy resin had low water absorption and low thermal expansion.

In Comparative Example 1, since the fiber base material is impregnated with the varnish having the same degree of viscosity, the impregnation rates of the first resin layer and the second resin layer are the same, and the impregnation rate is considered to be about 50%. . Furthermore, in Comparative Example 2, since the resin sheets having very close minimum melt viscosities are bonded to the fiber base material, the impregnation rates of the first resin layer and the second resin layer are approximately the same, and the impregnation rate is approximately 50%. It is thought that. In such Comparative Examples 1 and 2, since it is necessary to impregnate the fiber base material to the same extent with the first resin layer and the second resin layer, the selection of the resin composition is limited.
Further, in Comparative Example 1, the interface between the first resin layer and the second resin layer cannot be confirmed, and the first resin layer and the second resin layer are mixed. Therefore, the peel strength of the first resin layer is weaker than that of Example 1. Furthermore, the embedding property of the circuit pattern is inferior to that of Example 1, and the first resin layer and the second resin layer cannot exhibit desired characteristics.
Furthermore, the reliability between vias is poor, the thickness uniformity of the laminate is poor, and warping occurs. In Comparative Example 1, the point that the reliability between vias is poor is considered to be due to the non-uniform mixing of the varnish constituting the first resin layer and the varnish constituting the second resin layer.
Also in Comparative Example 2, the interface between the first resin layer and the second resin layer cannot be confirmed, and the first resin layer and the second resin layer are mixed. Therefore, the peel strength of the first resin layer is lower than the desired value. Further, in Comparative Example 2, warpage occurs in the laminated plate. This is because the first resin layer on the copper foil side has a low viscosity, and thus the thickness of the laminated plate varies.

This application claims priority based on Japanese Patent Application No. 2012-41917 filed on February 28, 2012 and Japanese Patent Application No. 2012-41886 filed on February 28, 2012. The entire disclosure of which is incorporated herein.

Claims

A fiber substrate;
A first resin layer that covers one surface side of the fiber substrate and is composed of a first resin composition;
Covering the other surface side of the fiber substrate, and comprising a second resin layer composed of a second resin composition different from the first resin composition,
The second resin layer is a prepreg impregnated in the fiber base material over at least 90% of the thickness of the fiber base material from the other surface of the fiber base material.
The prepreg according to claim 1,
A prepreg in which the first resin layer and the second resin layer are in contact with each other to form an interface.
The prepreg according to claim 1 or 2,
The first resin layer is a layer for providing a metal layer on the upper surface thereof,
The second resin layer is a prepreg that is a layer for embedding a circuit.
The prepreg according to any one of claims 1 to 3,
The first resin layer and the second resin layer are thermosetting layers and are semi-cured prepregs.
The prepreg according to any one of claims 1 to 4,
The second resin layer is impregnated in the fiber base material,
The first resin layer and the second resin layer are in contact with each other to form an interface;
The interface between the first resin layer and the second resin layer is a prepreg located outside the fiber substrate.
The prepreg according to any one of claims 1 to 5,
The prepreg in which the content of the thermoplastic resin in the first resin layer is larger than the content of the thermoplastic resin in the second resin layer.
The prepreg according to any one of claims 1 to 6,
90 ° peel strength A after superposing the first resin layer of the prepreg on copper foil and heat-treating under conditions of load 2 MPa, temperature 220 ° C., 1 hour,
A prepreg higher than 90 ° peel strength B after the second resin layer of the prepreg is superposed on a copper foil and heat-treated under the conditions of a load of 2 MPa, a temperature of 220 ° C. and 1 hour.
The prepreg according to claim 7, wherein
90 ° peel strength A-90 ° peel strength B ≧ 0.1 kN / m prepreg.
The prepreg according to any one of claims 1 to 8,
According to IPC-TM-650 Method 2.3.17, the resin flow measured by heating and pressurizing for 5 minutes under the conditions of 171 ± 3 ° C. and 1380 ± 70 kPa is 15 wt% or more and 50 wt% or less,
When the prepreg is sandwiched between a pair of opposing rubber plates and heated and pressurized under the conditions of 120 ° C. and 2.5 MPa, the first resin layer protruding from the outer edge of the fiber substrate in plan view and the The total weight of the second resin layer is 5% or less with respect to the total weight of the entire first resin layer and the entire second resin layer, and the rubber plate satisfies the following (i) to (iii): .
(I) Rubber hardness measured in accordance with JIS K 6253 A is 60 °
(Ii) Thickness 3mm
(Iii) Material is silicon
The prepreg according to any one of claims 1 to 9,
The first resin layer includes a thermoplastic resin,
The thermoplastic resin is a prepreg containing at least one of a phenoxy resin, a polyvinyl acetal resin, and a polyamide resin.
The prepreg according to any one of claims 1 to 10,
The second resin layer is a prepreg including an epoxy resin, a cyanate resin, and an inorganic filler.
The prepreg according to any one of claims 1 to 11,
At least one of the first resin layer and the second resin layer has a naphthalene skeleton, and the prepreg includes an epoxy resin having a structure in which the naphthalene skeleton is bonded to another arylene structure through an oxygen atom.
The prepreg according to any one of claims 1 to 12,
In the prepreg, the first resin layer is brought into contact with the first resin sheet as the first resin layer with respect to one surface of the fiber base material,
A prepreg produced by impregnating a second resin sheet serving as a second resin layer or a liquid composition containing the second resin composition from the other surface side of the fiber substrate.
The prepreg according to any one of claims 1 to 13,
Ratio η1 / of minimum melt viscosity η1 of the first resin layer and minimum melt viscosity η2 of the second resin layer in the range of 50 ° C. to 150 ° C. when the temperature is increased from 25 ° C. at a rate of 3 ° C./min. A prepreg having η2 of 1.1 or more and 100 or less.
The prepreg according to any one of claims 1 to 14,
The second resin layer is a prepreg containing silica having a particle size of 50 nm or less.
The prepreg according to claim 15, wherein
The fiber base material is a glass cloth,
A prepreg in which the silica is present in the strand of the glass cloth.
A substrate having a cured body of the prepreg according to any one of claims 1 to 16,
With a circuit layer,
The second resin layer of the cured body of the prepreg embeds the circuit layer,
The board | substrate with which the metal layer was provided on the said 1st resin layer of the hardening body of the said prepreg.
A substrate according to claim 17;
A semiconductor device comprising: a semiconductor element mounted on the substrate.
Providing a first resin layer made of the first resin composition by pressure-bonding the first resin sheet to one surface of the fiber base;
Forming a second resin layer made of a second resin composition different from the first resin composition on the other surface side of the fiber substrate,
In the step of forming the second resin layer,
The manufacturing method of the prepreg which forms the 2nd resin layer which impregnated the said fiber base material over 90% of the thickness of the said fiber base material from the other surface of the said fiber base material at least.
In the manufacturing method of the prepreg of Claim 19,
The method for producing a prepreg, wherein the first resin sheet has a minimum melt viscosity at 50 to 150 ° C. of 1000 Pa · s or more and 25000 Pa · s or less.
In the manufacturing method of the prepreg of Claim 19 or 20,
In the step of forming the second resin layer,
The manufacturing method of the prepreg which supplies a liquid 2nd resin composition to the other surface side of the said fiber base material.
In the manufacturing method of the prepreg of Claim 19 or 20,
In the step of forming the second resin layer,
Supplying the second resin sheet to be the second resin layer to the other surface side of the fiber substrate, heating the second resin sheet, and impregnating the fiber substrate;
Ratio η1 / of the lowest melt viscosity η1 of the first resin sheet and the lowest melt viscosity η2 of the second resin sheet in the range of 50 ° C. to 150 ° C. when the temperature is raised from 25 ° C. at a rate of 3 ° C./min. The manufacturing method of the prepreg whose (eta) 2 is 1.1 or more and 100 or less.
In the manufacturing method of the prepreg in any one of Claims 19 thru | or 22,
In the step of pressure-bonding the first resin sheet to one surface of the fiber base material,
Conveying the first resin sheet continuously along the outer peripheral surface of the laminate roll so that the first resin sheet is in direct or indirect surface contact with the laminate roll,
The fiber base material is continuously conveyed toward the laminating roll so as to come into contact with the laminating roll via the first resin sheet at a position where the laminating roll and the first resin sheet are in contact with each other. A method for manufacturing a prepreg.
In the manufacturing method of the prepreg in any one of Claim 19 thru | or 23,
The first resin sheet is wound in a roll shape, and the first resin sheet is delivered from the roll, and the first resin sheet is sent out in the step of pressure-bonding the first resin sheet to one surface of the fiber base material. A method for producing a prepreg, wherein the first resin sheet is pressure-bonded to one surface of a fiber base material.
In the manufacturing method of the prepreg in any one of Claim 19 thru | or 24,
The first resin sheet is formed on a support,
In the step of pressure-bonding the first resin sheet to one surface of the fiber base material, a prepreg manufacturing method in which the first resin sheet on the support is pressure-bonded to one surface of the fiber base material.