JP2024003431A - Multilayer transmission line plate and semiconductor package - Google Patents

Abstract

To provide a multilayer transmission line plate in which transmission loss is suppressed, and a semiconductor package having the multilayer transmission line plate.SOLUTION: There are provided a multilayer transmission line plate which includes a pair of ground layers, an insulation layer having the pair of ground layers on both surfaces, and a signal line provided in the insulation layer, wherein the isolation layer includes a first resin layer, a first composite layer, a second resin layer, a third resin layer, a second composite layer, and a fourth resin layer in this order, the first composite layer and the second composite layer are layers containing a fiber base material and a cured product of a resin composition, the first resin layer, the second resin layer, the third resin layer and the fourth resin layer are layers composed of a cured product of a resin composition containing no fiber base material, the signal line is formed on a surface on the third resin layer side of the second resin layer, the signal line is buried in the third resin layer layered on the second resin layer, and a relative dielectric constant at 10 GHz of the cured product of the resin composition constituting each of the layers has a specific relation; and a semiconductor package having the multilayer transmission line plate.SELECTED DRAWING: Figure 1

Description

This embodiment relates to a multilayer transmission line board and a semiconductor package.

BACKGROUND ART The speed and capacity of signals used in mobile communication devices such as mobile phones, network infrastructure devices such as base station devices, servers and routers, and electronic devices such as large computers are increasing year by year. In addition to the above-mentioned electronic devices, new systems that handle high-frequency radio signals are being put into practical use or are being planned to be put into practical use in the field of ITS related to automobiles and transportation systems, and in the field of indoor short-range communication. Accordingly, multilayer transmission line boards used in these electronic devices are required to reduce transmission loss of high frequency signals.

As a method of reducing transmission loss, for example, a method of reducing the surface roughness of a signal line has been proposed (see, for example, Patent Document 1).
Further, as a method of reducing transmission loss, a method of reducing the dielectric loss tangent of the substrate material is being considered.

Japanese Patent Application Publication No. 2004-064034

However, as mentioned above, the demand for reducing transmission loss has been increasing in recent years, and it has become difficult to sufficiently meet the demand using only the above-mentioned methods.

In view of the current situation, the present embodiment aims to provide a multilayer transmission line board with suppressed transmission loss, and a semiconductor package including the multilayer transmission line board.

The present inventors conducted studies to solve the above problems, and as a result, they found that the problems could be solved by the present embodiment described below.
That is, the present embodiment relates to the following [1] to [8].
[1] A pair of ground layers,
an insulating layer having the pair of ground layers on both sides;
A signal line provided in the insulating layer,
The insulating layer includes a first resin layer, a first composite layer, a second resin layer, a third resin layer, a second composite layer, and a fourth resin layer in this order. Including,
The first composite layer and the second composite layer are layers containing a fiber base material and a cured product of the resin composition,
The first resin layer, the second resin layer, the third resin layer, and the fourth resin layer are layers composed of a cured product of a resin composition that does not contain a fiber base material,
The signal line is formed on a surface of the second resin layer on the third resin layer side, and the signal line is embedded in the third resin layer laminated on the second resin layer. It is
The relative permittivity (R1) at 10 GHz of the cured product of the resin composition constituting the first resin layer and the relative permittivity (R2) at 10 GHz of the cured product of the resin composition constituting the second resin layer are , both of which are lower than the dielectric constant (C1) at 10 GHz of the cured product of the resin composition contained in the first composite layer,
The relative permittivity (R3) at 10 GHz of the cured resin composition constituting the third resin layer and the relative permittivity (R4) at 10 GHz of the cured resin composition constituting the fourth resin layer are , a multilayer transmission line board having a relative dielectric constant (C2) at 10 GHz of a cured product of the resin composition contained in the second composite layer.
[2] The difference between the relative permittivity (C1) and the relative permittivity (R1) [relative permittivity (C1) - relative permittivity (R1)], the relative permittivity (C1) and the relative permittivity ( R2) [relative permittivity (C1) - relative permittivity (R2)], the difference between the relative permittivity (C2) and the relative permittivity (R3) [relative permittivity (C2) - relative permittivity (R3)] and the difference between the relative permittivity (C2) and the relative permittivity (R4) [relative permittivity (C2) - relative permittivity (R4)] are both 0.03 or more. , the multilayer transmission line board according to [1] above.
[3] The above [1], wherein the relative permittivity (R1), the relative permittivity (R2), the relative permittivity (R3), and the relative permittivity (R4) are all 3.6 or less. Or the multilayer transmission line board according to [2].
[4] The multilayer transmission line board according to any one of [1] to [3] above, wherein the fiber base material is glass cloth.
[5] The multilayer transmission line according to any one of [1] to [4] above, wherein the thickness of the first composite layer and the thickness of the second composite layer are both 30 to 240 μm. Board.
[6] The thickness of the first resin layer, the second resin layer, the third resin layer, and the fourth resin layer are all 10 to 80 μm. The multilayer transmission line board according to any one of [1] to [5] above.
[7] The multilayer transmission line board according to any one of [1] to [6] above, wherein the signal line is a differential wiring.
[8] A semiconductor package comprising the multilayer transmission line board according to any one of [1] to [7] above and a semiconductor element.

According to this embodiment, it is possible to provide a multilayer transmission line board with suppressed transmission loss and a semiconductor package including the multilayer transmission line board.

FIG. 1 is a schematic cross-sectional view showing an example of a multilayer transmission line board according to the present embodiment. FIG. 3 is a schematic cross-sectional view showing another example of the multilayer transmission line board of the present embodiment. FIG. 2 is a schematic cross-sectional view of multilayer transmission line boards manufactured in Comparative Examples 1 and 2. 3 is a schematic cross-sectional view of a multilayer transmission line board manufactured in Comparative Example 3. FIG. 3 is a schematic cross-sectional view of a multilayer transmission line board manufactured in Comparative Example 4. FIG. 3 is a schematic cross-sectional view of a multilayer transmission line board manufactured in Comparative Example 5. FIG.

In this specification, a numerical range indicated using "~" indicates a range that includes the numerical values written before and after "~" as the minimum and maximum values, respectively.
For example, the notation of a numerical range "X to Y" (X and Y are real numbers) means a numerical range that is greater than or equal to X and less than or equal to Y. In this specification, the expression "X or more" means X and a numerical value exceeding X. Moreover, the description "Y or less" in this specification means Y and a numerical value less than Y.
The lower and upper limits of the numerical ranges described herein can be arbitrarily combined with the lower and upper limits of other numerical ranges, respectively.
In the numerical ranges described in this specification, the lower limit or upper limit of the numerical range may be replaced with the values shown in the examples.

Each component and material illustrated in this specification may be used alone or in combination of two or more, unless otherwise specified.
In the present specification, the content of each component in the resin composition refers to the content of each component in the resin composition, unless otherwise specified. means the total amount of
In this specification, the term "resin composition" includes a mixture of each component described below and a semi-cured product of the mixture.

In this specification, "solid content" means components other than the solvent, and includes those that are liquid, starch syrup-like, and wax-like at room temperature. Here, in this specification, room temperature refers to 25°C.

The mechanism of action described in this specification is speculation, and does not limit the mechanism by which the resin composition according to this embodiment exerts its effects.
This embodiment also includes aspects in which the items described in this specification are arbitrarily combined.

[Multilayer transmission line board]
FIG. 1 is a schematic cross-sectional view showing an example of a multilayer transmission line board according to this embodiment.
As shown in FIG. 1, the multilayer transmission line board 10 includes a pair of ground layers 11 and 12,
an insulating layer 13 having a pair of ground layers 11 and 12 on both sides;
A signal line 14 provided within the insulating layer 13.

<Ground layer>
The ground layers 11 and 12 are layers provided on both sides of the insulating layer 13.
Examples of the ground layers 11 and 12 include layers made of metal foil.
Examples of the metal foil include copper foil, nickel foil, aluminum foil, and the like. Among these, copper foil is preferred from the viewpoint of ease of handling and cost.
The metal foil may have a barrier layer made of, for example, nickel, tin, zinc, chromium, molybdenum, cobalt, etc. from the viewpoint of rust prevention, chemical resistance, and heat resistance.
Further, the metal foil may be subjected to, for example, surface roughening treatment, surface treatment with a silane coupling agent, etc., from the viewpoint of improving adhesiveness with the insulating layer.

The metal foil may be a commercially available metal foil. Commercially available metal foils include, for example, copper foil "F2-WS" (manufactured by Furukawa Electric Co., Ltd., trade name, roughened surface roughness Rz = 2.0 μm), "FV-WS" (manufactured by Furukawa Electric Co., Ltd., product name, roughened surface roughness Rz = 2.0 μm), Denki Kogyo Co., Ltd., product name, roughened surface roughness Rz = 1.5 μm), "3EC-VLP" (Mitsui Kinzoku Mining Co., Ltd., product name, roughened surface roughness Rz = 3.0 μm) etc.

The ground layers 11 and 12 may have a single-layer structure made of one kind of metal material, or may have a single-layer structure made of a plurality of metal materials. Further, the ground layers 11 and 12 may have a laminated structure in which a plurality of metal layers made of different materials are laminated.

The thickness of the ground layers 11 and 12 is not particularly limited, and may be determined as appropriate depending on the desired performance, and is, for example, 10 to 50 μm.

<Insulating layer>
The insulating layer 13 includes a first resin layer 13R(1), a first composite layer 13C(1), a second resin layer 13R(2), a third resin layer 13R(3), and a third resin layer 13R(3). The second composite layer 13C (2) and the fourth resin layer 13R (4) are included in this order.

In the multilayer transmission line board of this embodiment, the relative permittivity (R1) at 10 GHz of the cured resin composition constituting the first resin layer and the 10 GHz dielectric constant (R1) of the cured resin composition constituting the second resin layer. The relative permittivity (R2) at 10 GHz is lower than the relative permittivity (C1) at 10 GHz of the cured product of the resin composition contained in the first composite layer.
In addition, in the multilayer transmission line board of the present embodiment, the relative dielectric constant (R3) at 10 GHz of the cured resin composition constituting the third resin layer and the cured product of the resin composition constituting the fourth resin layer The relative dielectric constants (R4) at 10 GHz of both are lower than the relative permittivity (C2) at 10 GHz of the cured product of the resin composition contained in the second composite layer.
Note that the dielectric constant in this embodiment can be measured by the method described in Examples.

In the multilayer transmission line board of this embodiment, transmission loss can be suppressed because the dielectric constant of the cured product of the resin composition of each layer has the above relationship. Although the details of the cause are not certain, it is inferred as follows.
The multilayer transmission line board of this embodiment has an insulating layer between one ground layer and the signal line, and between the other ground layer and the signal line. The insulating layer has resin layers each having a relatively low dielectric constant in the vicinity of the ground layer and the signal line, and a resin composition having a relatively high dielectric constant between the resin layers. It has a composite layer containing a cured product. With this configuration, when transmitting signals, there is a difference in impedance between the resin layer and the composite layer, which changes the voltage distribution, and it is thought that the resin layer near the signal line and ground layer will have a higher voltage. . As a result, the electrical energy of the transmission signal is concentrated near the signal line and the ground layer, and it is presumed that transmission loss is suppressed.
Moreover, the multilayer transmission line board of this embodiment tends to have good mechanical strength, ease of handling, and productivity by having the first composite layer and the second composite layer.

The method for adjusting the dielectric constant of each layer to the above relationship is not particularly limited, and any known method may be used. For example, by adjusting the blending ratio of the components contained in the resin composition used to form each layer, which affect the dielectric constant of the cured product of the resin composition, the dielectric constant of each layer can be adjusted to the above relationship. Just adjust it.

The relative permittivity (C1) and the relative permittivity (C2) are not particularly limited, but from the viewpoint of further suppressing transmission loss, both are preferably 4.0 or less, more preferably 3.6 or less, and even more preferably is 3.4 or less.
In addition, the relative permittivity (C1) and the relative permittivity (C2) are not particularly limited, but from the viewpoint of ease of manufacture, they may be 2.0 or more, 2.5 or more, 3 It may be .0 or more.
Note that only one of the dielectric constant (C1) and the dielectric constant (C2) may be within the above range.

Relative permittivity (R1), relative permittivity (R2), relative permittivity (R3), and relative permittivity (R4) are not particularly limited, but from the viewpoint of further suppressing transmission loss, each is preferably 3. .6 or less, more preferably 3.4 or less, still more preferably 3.2 or less.
In addition, relative permittivity (R1), relative permittivity (R2), relative permittivity (R3), and relative permittivity (R4) are not particularly limited, but from the viewpoint of ease of manufacture, they should be 1.8 or more. It may be 2.3 or more, or 2.8 or more.
Furthermore, even if only one, two or three of the relative permittivity (R1), relative permittivity (R2), relative permittivity (R3) and relative permittivity (R4) are within the above range. good.

The absolute value of the difference between the relative permittivity (C1) and the relative permittivity (C2) is preferably small, and is not particularly limited, but is preferably 0 to 0.1, more preferably 0 to 0.05, even more preferably It is 0 to 0.02.

Absolute value of the difference between relative permittivity (R1) and relative permittivity (R2), absolute value of the difference between relative permittivity (R2) and relative permittivity (R3), relative permittivity (R3) and relative permittivity The absolute value of the difference from (R4) is preferably small, and is not particularly limited, but is preferably 0 to 0.1, more preferably 0 to 0.05, and even more preferably 0 to 0.02.
In addition, the absolute value of the difference between the relative permittivity (R1) and the relative permittivity (R2), the absolute value of the difference between the relative permittivity (R2) and the relative permittivity (R3), and the relative permittivity (R3) Of the absolute values of the difference with the dielectric constant (R4), only one or two may be within the above range.

Difference between relative permittivity (C1) and relative permittivity (R1) [relative permittivity (C1) - relative permittivity (R1)], difference between relative permittivity (C1) and relative permittivity (R2) [ratio dielectric constant (C1) - relative permittivity (R2)], difference between relative permittivity (C2) and relative permittivity (R3) [relative permittivity (C2) - relative permittivity (R3)], and relative permittivity The difference between the coefficient (C2) and the relative permittivity (R4) [relative permittivity (C2) - relative permittivity (R4)] is not particularly limited, but both are preferable from the viewpoint of further suppressing transmission loss. is 0.03 or more, more preferably 0.05 or more, even more preferably 0.08 or more.
Also, the difference between the relative permittivity (C1) and the relative permittivity (R1) [relative permittivity (C1) - relative permittivity (R1)], the difference between the relative permittivity (C1) and the relative permittivity (R2) [relative permittivity (C1) - relative permittivity (R2)], difference between relative permittivity (C2) and relative permittivity (R3) [relative permittivity (C2) - relative permittivity (R3)], and The difference between the relative permittivity (C2) and the relative permittivity (R4) [relative permittivity (C2) - relative permittivity (R4)] is not particularly limited, but from the viewpoint of ease of manufacture, it should be 1.0 or less. 0.8 or less, or 0.6 or less.
In addition, the difference [relative permittivity (C1) - relative permittivity (R1)], the difference [relative permittivity (C1) - relative permittivity (R2)], the difference [relative permittivity (C2) - relative permittivity (R3)] )] and the difference [relative permittivity (C2) - relative permittivity (R4)], only one, two, or three may be within the above range.

Next, each layer included in the insulating layer 13 will be explained in more detail.

(First and second composite layer)
In the multilayer transmission line board 10, the first composite layer 13C(1) is arranged between the first resin layer 13R(1) and the second resin layer 13R(2), and Layer 13C(2) is arranged between third resin layer 13R(3) and fourth resin layer 13R(4).
The multilayer transmission line board of this embodiment tends to have good mechanical strength, ease of handling, and productivity by having the first composite layer and the second composite layer.

The first composite layer 13C(1) and the second composite layer 13C(2) are layers containing a fiber base material and a cured product of a resin composition.
The fiber base materials contained in the first composite layer 13C(1) and the second composite layer 13C(2) may be the same or different.
The cured products of the resin compositions contained in the first composite layer 13C(1) and the second composite layer 13C(2) may be the same or different.

[Fiber base material]
As the fiber base material, for example, a densely knitted yarn or a spread fiber yarn is preferable from the viewpoint of further reducing the non-uniformity of the relative dielectric constant.
Materials for the fiber base material include, for example, natural fibers such as paper and cotton linters; inorganic fibers such as glass fiber and asbestos; organic fibers such as aramid, polyimide, polyvinyl alcohol, polyester, polytetrafluoroethylene, and acrylic; Examples include mixtures. Among these, glass fiber is preferable from the viewpoint of further reducing non-uniformity in relative dielectric constant.
As the glass fiber, glass cloth using E glass, NE glass, D glass, Q glass, etc. is preferable. The non-uniformity of the dielectric constant can be further reduced by using a glass cloth in which the warp and weft are made of glass fiber threads having a dielectric constant close to that of the resin to be impregnated. Moreover, if the same type of glass fiber yarn is used for the warp and weft, the non-uniformity of the relative permittivity can be further reduced in the same way.
The relative permittivity of the fiber base material is preferably 5.0 or less, more preferably 4.5 or less, from the viewpoint of reducing non-uniformity of the relative permittivity.

[Cured product of resin composition contained in first composite layer and second composite layer]
The cured product of the resin composition contained in the first composite layer and the second composite layer is preferably a cured product of a thermosetting resin composition.

Examples of thermosetting resins contained in the thermosetting resin composition include epoxy resins, phenol resins, maleimide resins, cyanate resins, isocyanate resins, benzoxazine resins, oxetane resins, amino resins, unsaturated polyester resins, and allyl resins. resin, dicyclopentadiene resin, silicone resin, triazine resin, melamine resin, etc. Among these, epoxy resins and maleimide resins are preferred from the viewpoint of heat resistance and conductor adhesion.
The thermosetting resin may be used alone or in combination of two or more.

In addition to the thermosetting resin, the thermosetting resin composition may contain, for example, resin components such as an elastomer and a curing agent; an inorganic filler; a curing accelerator; a flame retardant; and other additives.
Each of these may be used alone or in combination of two or more.

The content of the cured product of the resin composition in the first composite layer 13C(1) and the content of the cured product of the resin composition in the second composite layer 13C(2) are not particularly limited, but both are , preferably 80% by mass or less, more preferably 70% by mass or less, still more preferably 60% by mass or less.
Further, the content of the cured product of the resin composition in the first composite layer 13C(1) and the content of the cured product of the resin composition in the second composite layer 13C(2) are not particularly limited, but In any case, the content may be 20% by mass or more, 30% by mass or more, or 40% by mass or more.
Note that only one of the content of the cured product of the resin composition in the first composite layer 13C (1) and the content of the cured product of the resin composition in the second composite layer 13C (2) may be within the above range.

The thickness of the first composite layer 13C(1) and the thickness of the second composite layer 13C(2) are not particularly limited, but from the viewpoint of mechanical strength of the multilayer transmission line board, both are preferably 30 to 30. The thickness is 240 μm, more preferably 40 to 150 μm, even more preferably 60 to 130 μm.
Note that only one of the thickness of the first composite layer 13C(1) and the thickness of the second composite layer 13C(2) may be within the above range.

The absolute value of the difference between the thickness of the first composite layer 13C(1) and the thickness of the second composite layer 13C(2) is preferably smaller from the viewpoint of suppressing warping of the multilayer transmission line plate, and especially when limiting However, it is preferably 0 to 20 μm, more preferably 0 to 10 μm, and even more preferably 0 to 5 μm.

The dielectric constant at 10 GHz of the first composite layer 13C (1) and the dielectric constant at 10 GHz of the second composite layer 13C (2) are not particularly limited, but from the viewpoint of further suppressing transmission loss, both , preferably 4.7 or less, more preferably 4.5 or less, still more preferably 4.3 or less.
Further, the dielectric constant of the first composite layer 13C(1) at 10 GHz and the dielectric constant of the second composite layer 13C(2) at 10 GHz are not particularly limited, but both are 3.0 or more. It may be 3.5 or more, or 4.0 or more.
Note that only one of the dielectric constant at 10 GHz of the first composite layer 13C(1) and the dielectric constant at 10 GHz of the second composite layer 13C(2) may be within the above range.
The dielectric constant of the first composite layer 13C(1) at 10 GHz is preferably higher than the dielectric constant (C1), and the dielectric constant of the second composite layer 13C(2) at 10 GHz is higher than the dielectric constant (C1). It is preferable that it is higher than (C2).

(First to fourth resin layers)
In the multilayer transmission line board 10, the first resin layer 13R(1) is arranged between the ground layer 12 and the first composite layer 13C(1), and the second resin layer 13R(2) is arranged between the ground layer 12 and the first composite layer 13C(1). , is arranged between the first composite layer 13C(1) and the third resin layer 13R(3).
Further, the third resin layer 13R(3) is arranged between the second resin layer 13R(2) and the second composite layer 13C(2), and the fourth resin layer 13R(4) is arranged between the second composite layer 13C(2) and the ground layer 11.
In addition, in the following explanation, "first resin layer 13R (1), second resin layer 13R (2), third resin layer 13R (3), and fourth resin layer 13R (4)" is referred to as ""first to fourth resin layers 13R(1) to (4)" in some cases.

The first to fourth resin layers 13R(1) to (4) are layers composed of a cured product of a resin composition that does not contain a fiber base material.
The cured products of the resin compositions constituting the first to fourth resin layers 13R(1) to (4) may be the same or different.

[Cured product of resin composition constituting the first to fourth resin layers]
The cured product of the resin composition constituting the first to fourth resin layers is preferably a cured product of a thermosetting resin composition.
The explanation about the components constituting the thermosetting resin composition that can be used for the first to fourth resin layers is the same as the explanation for the thermosetting resin composition that can be used for the first composite layer and the second composite layer. It is. The dielectric constant of each layer may be adjusted by adjusting the blending amount of components that affect the dielectric constant, as described above.

The thickness of the first to fourth resin layers 13R(1) to (4) is not particularly limited, but from the viewpoint of further suppressing transmission loss, each thickness is preferably 10 to 80 μm, more preferably 15 to 80 μm. The thickness is 60 μm, more preferably 20 to 40 μm.
Note that only one, two or three of the thicknesses of the first to fourth resin layers 13R(1) to (4) may fall within the above range.

The absolute value of the difference between the thickness of the first resin layer 13R(1) and the thickness of the second resin layer 13R(2), the thickness of the second resin layer 13R(2) and the third resin layer 13R(3 ), and the absolute value of the difference between the thickness of the third resin layer 13R (3) and the thickness of the fourth resin layer 13R (4), suppress warping of the multilayer transmission line board. The smaller the better from the point of view of this, and although not particularly limited, it is preferably 0 to 20 μm, more preferably 0 to 10 μm, and even more preferably 0 to 5 μm.
The absolute value of the difference between the thickness of the first resin layer 13R(1) and the thickness of the second resin layer 13R(2), the thickness of the second resin layer 13R(2) and the third resin layer 13R (3), and the absolute value of the difference between the thickness of the third resin layer 13R(3) and the fourth resin layer 13R(4), or Only two may be within the above range.

The thickness of the first resin layer 13R(1) is preferably smaller than the thickness of the first composite layer 13C(1) from the viewpoint of the mechanical strength of the substrate.
Further, the thickness of the second resin layer 13R(2) is preferably smaller than the thickness of the first composite layer 13C(1) from the viewpoint of the mechanical strength of the substrate.
Further, the thickness of the third resin layer 13R(3) is preferably smaller than the thickness of the second composite layer 13C(2) from the viewpoint of the mechanical strength of the substrate.
Further, the thickness of the fourth resin layer 13R(4) is preferably smaller than the thickness of the second composite layer 13C(2) from the viewpoint of the mechanical strength of the substrate.

The difference between the thickness of the first composite layer 13C(1) and the thickness of the first resin layer 13R(1) [first composite layer-first resin layer], The difference between the thickness and the thickness of the second resin layer 13R(2) [first composite layer - second resin layer], the difference between the thickness of the second composite layer 13C(2) and the third resin layer 13R(3) ) [second composite layer - third resin layer], and the difference between the thickness of the second composite layer 13C (2) and the thickness of the fourth resin layer 13R (4) [second composite layer-fourth resin layer] is not particularly limited, but preferably has a thickness of 10 to 150 μm, more preferably 30 to 100 μm, and even more preferably 50 to 80 μm.
Note that the above thickness difference [first composite layer - first resin layer], the above thickness difference [first composite layer - second resin layer], the above thickness difference [second composite layer], layer - third resin layer] and the above-mentioned thickness difference [second composite layer - fourth resin layer], only one, two or three of them may be within the above range.

The thickness of the third resin layer 13R(3) is preferably greater than the thickness of the signal line 14 in order to embed the signal line 14.

The insulating layer 13 may have only the first to fourth resin layers 13R (1) to (4), the first composite layer (C1), and the second composite layer (C2) as insulating layers. Alternatively, it may further include an insulating layer other than these.
In the insulating layer 13, the second resin layer 13R(2) and the third resin layer 13R(3) have a structure in which they are directly laminated at a position other than the position where the signal line 14 is formed. Further, the first resin layer 13R(1) and the ground layer 12, and the fourth resin layer 13R(4) and the ground layer 11 have a structure in which they are directly laminated.
On the other hand, the first resin layer 13R(1) and the first composite layer 13C(1) may be directly laminated or may have another layer interposed therebetween, but it is preferable that they are directly laminated. .
Further, the first composite layer 13C(1) and the second resin layer 13R(2) may be directly laminated or may have another layer interposed therebetween, but it is preferable that they are directly laminated. .
Further, the third resin layer 13R(3) and the second composite layer 13C(2) may be directly laminated or may be interposed with another layer, but it is preferable that they are directly laminated. .
Further, the second composite layer 13C(2) and the fourth resin layer 13R(4) may be directly laminated or may have another layer interposed therebetween, but it is preferable that they are directly laminated. .

<Signal line>
The signal line 14 is formed on the surface of the second resin layer 13R(2) on the third resin layer 13R(3) side, and is formed on the third resin layer laminated on the second resin layer 13R(2). It is embedded in layer 13R(3).

The material forming the signal line 14 is not particularly limited, and for example, a metal foil that can be used as a ground layer can be used. Further, the signal line 14 may be formed by plating.
The shape of the signal line 14 in cross-section is not particularly limited, but is, for example, rectangular.
The thickness of the signal line 14 is not particularly limited, and may be determined as appropriate depending on the desired performance, and is, for example, 5 to 35 μm.

In the multilayer transmission line board 10 shown in FIG. 1, the signal line 14 is a single wire, but the form of the signal line included in the multilayer transmission line board of this embodiment is not particularly limited, and may be a differential wiring, for example. .
FIG. 2 shows a multilayer transmission line board 20 having differential wiring 14a.
The multilayer transmission line board 20 shown in FIG. 2 has a configuration in which the signal line 14, which is a single wiring, in the multilayer transmission line board 10 of FIG. 1 is replaced with a differential wiring 14a.

<Method for manufacturing multilayer transmission line board>
Next, a method for manufacturing a multilayer transmission line board according to the present embodiment will be explained using the multilayer transmission line board 10 shown in FIG. 1 as an example. Any method may be used as long as it can manufacture a multilayer transmission line board having the following structure.

The multilayer transmission line board 10 includes, for example, prepreg for forming the first composite layer 13C(1) and the second composite layer 13C(2), and the first to fourth resin layers 13R(1) to (4) It can be manufactured using a resin film for forming.

The prepreg can be produced, for example, by a method in which a fiber base material is impregnated with a resin varnish obtained by diluting a predetermined resin composition with an organic solvent and then dried.
Commercially available prepregs may be used. Examples of commercially available prepregs include "GWA-900G", "GWA-910G", "GHA-679G", and "GHA-679G" manufactured by Showa Denko Materials Co., Ltd. (S)” and “GZA-71G” (all product names).

The resin film can be produced, for example, by applying a resin varnish prepared by diluting a predetermined resin composition with an organic solvent to a support and drying it.
A commercially available resin film may be used, and examples of commercially available resin films include "AS-400HS" (trade name) manufactured by Showa Denko Materials Co., Ltd.

The multilayer transmission line board 10 can be manufactured, for example, by a method including the following (1) to (3).
(1) One sheet of prepreg for forming the first composite layer 13C (1), one sheet of resin film for forming the first resin layer 13R (1) on one side, and a sheet of prepreg for forming the first composite layer 13C (1) on the other side. One resin film for forming the second resin layer 13R(2) is stacked, copper foil is placed on both sides, and then heat and pressure molding is performed. A double-sided copper-clad laminate having the resin layer 13R(1), the first composite layer 13C(1), the second resin layer 13R(2), and copper foil in this order is formed.
(2) The copper foil on the second resin layer 13R(2) side of the double-sided copper-clad laminate obtained in (1) above is patterned by etching to form the signal line 14.
(3) One resin film for forming the third resin layer 13R(3) and prepreg for forming the second composite layer 13C(2) on the signal line 14 formed in (2) above. One resin film for forming the fourth resin layer 13R (4) and a copper foil for forming the ground layer 11 are stacked in this order and heated and pressure molded to form the multilayer transmission line board 10. get.
Thereafter, drilling, through-hole plating, etc. may be performed as necessary.
As the method and conditions for heat and pressure molding, known methods and conditions can be applied in consideration of the materials to be used.
The multilayer transmission line board of this embodiment having a configuration other than the multilayer transmission line board 10, such as the multilayer transmission line board 20 shown in FIG. 2, can also be manufactured by a method similar to the above.

The multilayer transmission line board of this embodiment is suitably used for electronic equipment that handles high frequency signals of 1 GHz or more, and particularly for electronic equipment that handles high frequency signals of 10 GHz or more or 30 GHz or more.

[Semiconductor package]
The semiconductor package of this embodiment is a semiconductor package that includes the multilayer transmission line plate of this embodiment and a semiconductor element.
The semiconductor package of this embodiment can be manufactured by, for example, mounting a semiconductor element, a memory, etc. on the multilayer transmission line board of this embodiment by a known method.

Hereinafter, this embodiment will be described in more detail based on Examples, but this embodiment is not limited to the following Examples.

[Method of measuring relative permittivity]
The prepreg used in each example or the resin composition used as the resin film forming material was applied to a 38 μm thick PET film (manufactured by Teijin Ltd., product name: G2-38), and then heated and dried at 170°C for 5 minutes. In this way, a resin film in a B-stage state was produced. After this resin film was peeled from the PET film, it was crushed to obtain resin powder in a B-stage state, and the resin was placed in a Teflon (registered trademark) sheet cut into a size of 0.8 mm thick x 50 mm long x 35 mm wide. Next, 18 μm thick low profile copper foil (trade name: 3EC-VLP-18, manufactured by Mitsui Mining & Mining Co., Ltd.) was placed above and below the Teflon (registered trademark) sheet containing the resin powder, and heated and pressed. A laminate was obtained before molding. Note that the low profile copper foil was placed with the M side facing the resin powder side. Subsequently, the laminate was heated and pressure-molded at a temperature of 230° C., a pressure of 2.0 MPa, and a time of 120 minutes to form and harden the resin powder into a resin plate, thereby producing a resin plate with double-sided copper foil. did. The thickness of the resin plate portion of the obtained resin plate with copper foil on both sides was 0.8 mm.
The copper foil was removed by immersing the resin plate with copper foil on both sides obtained above in a 10% by mass solution of ammonium persulfate (manufactured by Mitsubishi Gas Chemical Co., Ltd.), which is a copper etching solution, to prepare a test piece. Next, the dielectric constant of the test piece was measured at an ambient temperature of 25° C. and a 10 GHz band according to the split post dielectric resonator method.

[Manufacture of multilayer transmission line board]
Next, a method for manufacturing a multilayer transmission line board in each example will be explained.
In each example, the copper foil used was manufactured by Mitsui Kinzoku Mining Co., Ltd. under the trade name "3EC-VLP-18" (roughened surface roughness Rz: 3.0 μm, thickness 18 μm).
The heating and pressurizing conditions for laminating and integrating each component were a temperature of 230° C., a pressure of 3.0 MPa, and a time of 80 minutes.

Examples 1 to 3
The multilayer transmission line boards of Examples 1 to 3 were manufactured according to the following procedure so that the structure of the insulating layer was as shown in Table 1.
Note that a schematic cross-sectional view of the multilayer transmission line plate manufactured in Examples 1 and 2 is shown in FIG. 1, and a schematic cross-sectional view of the multilayer transmission line plate manufactured in Example 3 is shown in FIG.

One resin film, one prepreg, and one resin film listed in Table 1 are stacked in this order, and then copper foil is stacked on both sides of the film, and then a lamination integration process is performed to form the copper foil as the ground layer 12. A double-sided copper-clad laminate having the first resin layer 13R(1), the first composite layer 13C(1), the second resin layer 13R(2), and copper foil in this order was formed.
Next, the copper foil on the second resin layer 13R(2) side of the double-sided copper-clad laminate produced above is patterned by etching to form the signal line 14, which is a single wiring, or the signal line 14a, which is a differential wiring. Formed.
On the signal line formed above, one resin film, one prepreg, one resin film, and copper foil listed in Table 1 are laminated in this order and laminated and integrated, as shown in FIG. 1 or 2. A multilayer transmission line board having the following structure was obtained.
Thereafter, the obtained multilayer transmission line board was drilled and through-hole plated, and then both sides were patterned by etching to form a probing pattern used for measurement of transmission loss, which will be described later.

Comparative examples 1 and 2
The multilayer transmission line boards of Comparative Examples 1 and 2 were manufactured according to the following procedure so that the structure of the insulating layer was as shown in Table 1. Note that FIG. 3 shows a schematic cross-sectional view of the multilayer transmission line boards manufactured in Comparative Examples 1 and 2.
By superimposing copper foil on both sides of the prepreg shown in Table 1 and performing a lamination integration process, a laminate having copper foil as the ground layer 12, an insulating layer 13C, and a copper foil in this order was obtained.
Next, the signal line 14 was formed on the insulating layer 13C by patterning the copper foil of the laminate obtained above by etching.
On the signal line 14 formed above, one sheet of prepreg and copper foil listed in Table 1 were laminated in this order and laminated and integrated, to obtain a multilayer transmission line board having the configuration shown in FIG. 3.

Comparative example 3
The multilayer transmission line board of Comparative Example 3 was manufactured according to the following procedure so that the structure of the insulating layer was as shown in Table 1. Note that a schematic cross-sectional view of the multilayer transmission line plate manufactured in Comparative Example 3 is shown in FIG.
By overlapping two sheets of prepreg shown in Table 1, overlapping copper foil on both sides, and performing a lamination integration process, a laminate having the ground layer 12, insulating layer 13C, insulating layer 13C, and copper foil in this order is obtained. Ta.
Next, the signal line 14 was formed on the insulating layer 13C by patterning the copper foil of the laminate obtained above by etching.
On the signal line 14 formed above, two sheets of prepreg and copper foil listed in Table 1 were laminated in this order and subjected to a lamination integration process to obtain a multilayer transmission line board having the configuration shown in FIG. 4.

Comparative example 4
The multilayer transmission line board of Comparative Example 4 was manufactured in the same manner as the multilayer transmission line board of Comparative Example 1, except that the signal line 14 in the multilayer transmission line board of Comparative Example 1 was changed to the differential wiring 14a. . Note that a schematic cross-sectional view of the multilayer transmission line plate manufactured in Comparative Example 4 is shown in FIG.

Comparative example 5
The multilayer transmission line board of Comparative Example 5 was manufactured according to the following procedure so that the structure of the insulating layer was as shown in Table 1. Note that a schematic cross-sectional view of the multilayer transmission line plate manufactured in Comparative Example 5 is shown in FIG.
One resin film listed in Table 1, one prepreg 1, and one resin film are stacked in this order, and then copper foil is stacked on both outsides of the film, and then an integrated lamination process is applied to the copper foil and resin film. A double-sided copper-clad laminate having layer 13R, composite layer 13C, resin layer 13R, and copper foil in this order was formed.
Next, one copper foil of the double-sided copper-clad laminate produced above was patterned by etching to form differential wiring 14a.
On the differential wiring 14a formed above, one sheet of prepreg 2 listed in Table 1 and a copper foil are laminated in this order and laminated and integrated, thereby producing a multilayer transmission line board having the configuration shown in FIG. Obtained.

[Method of measuring transmission loss]
The transmission loss of the multilayer transmission line board obtained in each example was measured using a network analyzer (manufactured by Agilent Technologies, trade name "N5227A") according to the following procedure.
By attaching probes on the input side and output side to the signal line of the multilayer transmission line plate to the probing pattern of the multilayer transmission line plate manufactured in each of the above examples, inputting a signal of a predetermined frequency, and measuring the output signal. , we measured the transmission loss at each frequency.
Note that the influence of the probing pattern was corrected by TRL calibration (Thru-Reflect-Line calibration).
The transmission loss is a negative value, and the smaller the absolute value, the smaller the transmission loss.

Details of the prepreg and resin film listed in Table 1 are as follows.
Prepreg 1 to 4: Manufactured by Showa Denko Materials Co., Ltd., trade name "GHA-679G(S)" (provided that it has the thickness and resin composition content listed in Table 1).
Resin film 1: Manufactured by Showa Denko Materials Co., Ltd., product name “AS-400HS”
Resin film 2: A resin film made by adding 10% by mass of epoxy resin to the total solid content of the resin composition used in the product name "AS-400HS" manufactured by Showa Denko Materials Co., Ltd. .

From the results in Table 1, it can be seen that the multilayer transmission line plates of Examples 1 to 3 of the present embodiment are able to suppress transmission loss more than the multilayer transmission line plates of Comparative Examples 1 to 5.

10, 20, 30, 40, 50, 60 Multilayer transmission line board 11, 12 Ground layer 13 Insulating layer 13C Composite layer 13C (1) First composite layer 13C (2) Second composite layer 13R Resin layer 13R (1 ) First resin layer 13R (2) Second resin layer 13R (3) Third resin layer 13R (4) Fourth resin layer 14 Signal line 14a Differential wiring

Claims (8)

A pair of ground layers,
an insulating layer having the pair of ground layers on both sides;
A signal line provided in the insulating layer,
The insulating layer includes a first resin layer, a first composite layer, a second resin layer, a third resin layer, a second composite layer, and a fourth resin layer in this order. Including,
The first composite layer and the second composite layer are layers containing a fiber base material and a cured product of the resin composition,
The first resin layer, the second resin layer, the third resin layer, and the fourth resin layer are layers composed of a cured product of a resin composition that does not contain a fiber base material,
The signal line is formed on a surface of the second resin layer on the third resin layer side, and the signal line is embedded in the third resin layer laminated on the second resin layer. It is
The relative permittivity (R1) at 10 GHz of the cured product of the resin composition constituting the first resin layer and the relative permittivity (R2) at 10 GHz of the cured product of the resin composition constituting the second resin layer are , both of which are lower than the dielectric constant (C1) at 10 GHz of the cured product of the resin composition contained in the first composite layer,
The relative permittivity (R3) at 10 GHz of the cured resin composition constituting the third resin layer and the relative permittivity (R4) at 10 GHz of the cured resin composition constituting the fourth resin layer are , a multilayer transmission line board having a relative dielectric constant (C2) at 10 GHz of a cured product of the resin composition contained in the second composite layer. The difference between the relative permittivity (C1) and the relative permittivity (R1) [relative permittivity (C1) - relative permittivity (R1)], the relative permittivity (C1) and the relative permittivity (R2) [relative permittivity (C1) - relative permittivity (R2)], difference between the relative permittivity (C2) and the relative permittivity (R3) [relative permittivity (C2) - relative permittivity (R3)] ], and the difference between the relative permittivity (C2) and the relative permittivity (R4) [relative permittivity (C2) - relative permittivity (R4)] are both 0.03 or more. 1. The multilayer transmission line board according to 1. The relative permittivity (R1), the relative permittivity (R2), the relative permittivity (R3), and the relative permittivity (R4) are all 3.6 or less, according to claim 1 or 2. multilayer transmission line board. The multilayer transmission line board according to claim 1 or 2, wherein the fiber base material is glass cloth. The multilayer transmission line board according to claim 1 or 2, wherein the thickness of the first composite layer and the thickness of the second composite layer are both 30 to 240 μm. The thickness of the first resin layer, the second resin layer, the third resin layer, and the fourth resin layer are all 10 to 80 μm. The multilayer transmission line board according to claim 1 or 2. The multilayer transmission line board according to claim 1 or 2, wherein the signal line is a differential wiring. A semiconductor package comprising the multilayer transmission line board according to claim 1 or 2 and a semiconductor element.