JP6519187B2 - Multilayer transmission line board - Google Patents

Description

  The present invention relates to a multilayer transmission line board, and more particularly, to a multilayer transmission line board used for high-speed digital transmission by a differential transmission scheme of Gbps order.

  With the speeding up of signals, differential transmission schemes are widely used. The differential transmission scheme is advantageous for noise reduction, but with the increase in speed of signals, signal degradation due to the occurrence of common mode noise has become a problem.

By the way, a composite material of glass cloth and resin is widely used in the insulating layer of the multilayer transmission line plate in order to ensure the handling of the material in manufacturing the multilayer transmission line plate and the mechanical characteristics of the multilayer transmission line plate itself. It is done.
As shown in FIG. 1, since the glass cloth has a structure in which glass fibers are longitudinally and horizontally woven, glass fibers overlap in the weave portion. Therefore, in the composite material of the glass cloth and the resin, the glass fiber weave portion has a high proportion of glass. On the contrary, the non-overlapping portion of the glass fibers has a low glass content. Thus, the abundance ratio of resin to glass in the composite material plane is not uniform.

Since the dielectric constant is different between the resin and the glass, if the ratio of the resin to the glass in the surface of the composite material is nonuniform, the dielectric constant in the surface of the composite material also becomes nonuniform.
As shown in FIG. 2, in the case of the multilayer transmission line plate in which the differential wiring is formed, the wiring may be present in the portion where the glass abundance ratio is high and the portion where the glass is low. At the reception side, a shift (skew) occurs in the arrival time of the signal, which degrades the signal quality.

  As measures against skew, measures have been taken by design technology such as arranging the wiring pattern diagonally to the weave direction of glass, but according to this method, imposition of the wiring pattern becomes inefficient and material loss And another solution is needed.

  Patent Document 1 discloses a method of intensively adding a filler having a high dielectric constant to a non-woven portion of a glass cloth to homogenize the dielectric constant in the surface of the composite material.

JP, 2009-259879, A

However, according to the method of Patent Document 1, in addition to the increase in material cost, there are cases in which it is difficult to control the material quality because the material manufacturing process is complicated.
In addition, as a measure against skew, a method of constructing a multilayer transmission line plate only with a film material not containing glass cloth has also been proposed, but in general, the film material is inferior in rigidity to a material containing glass cloth. According to the above, there are cases in which the handleability at the time of manufacturing the multilayer transmission line board is lowered, and the mechanical strength of the multilayer transmission line board is lowered.

  Then, this invention makes it a subject to provide the multilayer transmission line board which can reduce skew in differential transmission, without using a complicated process.

MEANS TO SOLVE THE PROBLEM As a result of advancing examination so that the said subject might solve said subject, it discovered that the said subject could be solved by the following this invention. That is, the present invention provides the following [1] to [4].
[1] Between a pair of ground layers, a differential wiring disposed between one ground layer and the other ground layer of the pair of ground layers, between the differential wiring and the one ground layer And an insulating layer II disposed between the differential wiring and the other ground layer, wherein the insulating layer I contains no resin and contains a resin. Multilayer, wherein the insulating layer I or the insulating layer II has a layer containing a glass cloth and a resin, and the thickness of the insulating layer I is equal to or less than the thickness of the insulating layer II Transmission line board.
[2] Between a pair of ground layers, a differential wiring disposed between one ground layer and the other ground layer of the pair of ground layers, between the differential wiring and the one ground layer And an insulating layer (1-II) disposed between the differential wiring and the other ground layer, wherein the insulating layer (1-I) And a layer not containing glass cloth but containing resin, wherein the insulating layer (1-II) is a layer containing glass cloth and a resin, and the thickness of the insulating layer (1-I) is A multilayer transmission line plate, which is equal to or less than the thickness of the insulating layer (1-II).
[3] Between a pair of ground layers, a differential wiring disposed between one ground layer and the other ground layer of the pair of ground layers, between the differential wiring and the one ground layer And an insulating layer (2-II) disposed between the differential wiring and the other ground layer, wherein the insulating layer (2-II) An insulating layer (2-IIA) and an insulating layer (2-IIB) laminated on the insulating layer (2-IIA), the insulating layer (2-I) containing a glass cloth and a resin The insulating layer (2-IIA) is a layer containing no resin and containing a resin, and the insulating layer (2-IIB) is a layer containing a glass cloth and a resin. Multilayer, wherein the thickness of the insulating layer (2-II) is equal to or less than the thickness of the insulating layer (2-I). Line plate.
[4] Between a pair of ground layers, a differential wiring disposed between one ground layer and the other ground layer of the pair of ground layers, between the differential wiring and the one ground layer And an insulating layer (3-II) disposed between the differential wiring and the other ground layer, wherein the insulating layer (3-II) An insulating layer (3-IIA) and an insulating layer (3-IIB) stacked on the insulating layer (3-IIA), wherein the insulating layer (3-I) does not contain glass cloth, It is a layer containing a resin, and the insulating layer (3-IIA) is a layer containing no glass cloth and containing a resin, and the insulating layer (3-IIB) contains a glass cloth and a resin. Multilayer transmission line board.

  According to the present invention, it is possible to provide a multilayer transmission line plate capable of reducing skew in differential transmission without using a complicated process.

It is a schematic diagram which shows the weave of glass cloth. It is a schematic diagram which shows the example of arrangement | positioning of glass cloth and differential wiring. It is a typical sectional view showing the multilayer transmission line board concerning a first embodiment (example 1) of the present invention. It is a schematic cross section which shows the multilayer transmission line board which concerns on 2nd embodiment (Example 4) of this invention. It is a schematic cross section which shows the multilayer transmission line board which concerns on 3rd embodiment (Example 7) of this invention. It is a typical sectional view showing the conventional multilayer transmission line board. It is a typical sectional view showing a multilayer transmission line board manufactured by comparative example 2 of the present invention. It is a typical sectional view showing the multilayer transmission line board manufactured by comparative example 3 of the present invention.

Unless otherwise indicated, all numbers denoting the size, amount, and physical characteristics of the features used in the specification and claims are to be modified in all cases by the term "about". It should be understood. Therefore, unless indicated to the contrary, the numerical parameters set forth in the foregoing specification and appended claims are intended to be targeted by one of ordinary skill in the art using the teachings disclosed herein. Is an approximate value that can vary depending on the characteristics of The use of numerical ranges by endpoints includes all numbers contained within that range (eg, 1 to 5: 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5). And any range within that range is included.
Hereinafter, embodiments of the multilayer transmission line board of the present invention will be described in detail with reference to the drawings.

  In addition, if the "differential wiring" in the present disclosure is a conductor layer subjected to circuit processing to function as a differential wiring of the manufactured multilayer transmission line plate, the "differential wiring" may be used in the manufacturing process of the multilayer transmission line plate. It also includes the conductor layer. Similarly, the “ground layer” includes a conductor layer in the process of manufacturing a multilayer transmission line plate, as long as the conductor layer functions as a ground layer of the manufactured multilayer transmission line plate.

[Multilayer transmission line board]
The multilayer transmission line board according to the present embodiment is used in high-speed digital transmission by a differential transmission method in Gbps order.
The multilayer transmission line board of the present invention comprises a pair of ground layers, a differential wiring disposed between one ground layer and the other ground layer of the pair of ground layers, the differential wiring, and the one side. And an insulating layer II disposed between the differential wiring and the other ground layer, wherein the thickness of the insulating layer I is The thickness is equal to or less than the thickness of the insulating layer II, the insulating layer I does not contain glass cloth, has a layer containing a resin, and the insulating layer I or the insulating layer II contains a glass cloth and a resin. It is a multilayer transmission line board which has a layer.
In the multilayer transmission line board of the present invention, the dielectric constant is nonuniform by using a material not containing glass cloth as a part of the insulating layer formed of the material containing glass cloth in the conventional multilayer transmission line board. It is considered that skew can be reduced by reducing the stiffness.
Hereinafter, as an embodiment of the multilayer transmission line board of the present invention, the multilayer transmission line boards according to the first to third embodiments will be described as an example, and each aspect will be described with reference to the drawings.

<Multilayer Transmission Line Board According to First Embodiment>
FIG. 3 is a schematic cross-sectional view showing a multilayer transmission line plate 1A according to the first embodiment of the present invention.
As shown in FIG. 3, the multilayer transmission line plate 1A according to the first embodiment of the present invention includes a pair of ground layers 11 and 21, and one ground layer 11 and the other ground of the pair of ground layers 11 and 21. Differential wiring 91 disposed between layer 12 and an insulating layer (1-I) 31 disposed between differential wiring 91 and one ground layer 11, differential wiring 91 and the other ground And an insulating layer (1-II) 32 disposed between the layer 21 and the other. Insulating layer (1-I) 31 is a layer not containing glass cloth but containing resin, and insulating layer (1-II) 32 is a layer containing glass cloth and resin, and an insulating layer It is a multilayer transmission line plate in which the thickness of 1-I) 31 is equal to or less than the thickness of the insulating layer (1-II) 32.

In the multilayer transmission line plate 1A according to the first embodiment of the present invention, a material not containing glass cloth is used for part of the insulating layer formed of the material containing glass cloth in the conventional multilayer transmission line plate. It is considered that skew can be reduced by reducing the nonuniformity of the dielectric constant.
FIG. 6 shows a schematic cross-sectional view of a conventional multilayer transmission line plate 4A. In the conventional multilayer transmission line board 4A, differential wiring 94 is formed on one side by applying circuit processing to copper foil on one side of a laminated board obtained by laminating and curing copper foil on both sides of a prepreg. The insulating layer 62 having the ground layer 24 disposed on the other surface is formed, and the prepreg for forming the insulating layer 61 on the surface on the differential wiring 94 side and the copper foil constituting the ground layer 14 are in this order It manufactured by the method of laminating | stacking and shape | molding.
In the multilayer transmission line plate 1A according to the first embodiment of the present invention, the insulating layer 61 in the conventional multilayer transmission line plate 4A shown in FIG. By changing to 1-I) 31, it is possible to reduce the skew without impairing the handleability.
At this time, it is important that the thickness of the insulating layer (1-I) 31 be equal to or less than the thickness of the insulating layer (1-II) 32.
This is because a stronger electric field is generated on the thin insulating layer side at the time of signal transmission, so that the electrical characteristics of the insulating layer are more strongly reflected in the signal transmission characteristics. That is, in order to reflect the uniformity of the dielectric constant of the insulating layer (1-I) 31 which is a layer not containing glass cloth and containing a resin, the thickness of the insulating layer (1-I) 31 is It is important that the thickness is the same as the thickness of the insulating layer (1-II) 32 which is a layer containing glass cloth and resin, or thinner than the thickness of the insulating layer (1-II) 32.

(Ground layers 11, 21)
The ground layers 11 and 21 are not particularly limited, but those applied to a conductive layer such as a conventional printed wiring board can be applied. For example, a layer composed of metal foil is applied. be able to.
As metal foil, copper foil, nickel foil, aluminum foil etc. can be applied, for example, and copper foil can be applied from a viewpoint of handling nature and cost.
When a metal foil is applied to the ground layers 11 and 21, the barrier layer is formed with nickel, tin, zinc, chromium, molybdenum, cobalt or the like from the viewpoint of improving the corrosion resistance, chemical resistance, heat resistance, etc. May be applied. The metal foil may be subjected to surface treatment such as surface roughening treatment, treatment with a silane coupling agent, or the like from the viewpoint of improving adhesion to the insulating layer.
A commercially available metal foil may be used as the metal foil applied to the ground layers 11 and 21. Examples of commercially available metal foils include copper foil “F2-WS” (Furukawa Electric Co., Ltd., trade name, Rz = 2.0 μm), “F0-WS” (Furukawa Electric Co., Ltd., A trade name, Rz = 1.2 μm), “3 ECVLP” (trade name, Rz = 3.0 μm, manufactured by Mitsui Mining & Smelting Co., Ltd.), and the like are commercially available.
The ground layers 11 and 21 may have a single-layer structure made of one type of metal material, or may have a single-layer structure made of a plurality of metal materials, and further a plurality of laminated metal layers of different materials. It may be a structure. Further, the thickness of the ground layers 11 and 21 is not particularly limited, and may be appropriately determined according to the required performance and the like.

(Differential wiring 91)
The material for forming the differential wiring 91 is not particularly limited, and, for example, one composed of metal foil can be applied. As metal foil which forms differential wiring 91, metal foil applicable to grand layers 11 and 21 can be used, for example.

[Insulating layer (1-I) 31]
Insulating layer (1-I) 31 is a layer which does not contain glass cloth but contains resin.

«Resin»
The resin contained in the insulating layer (1-I) 31 is not particularly limited, and a thermoplastic resin, a thermosetting resin, etc. can be used, and dielectric properties, heat resistance, solvent resistance, and press molding From the viewpoint of improving the properties, the thermoplastic resin may be a resin modified with a thermosetting resin.
As a thermoplastic resin, for example, styrene-butadiene copolymer, polystyrene, triallyl cyanurate, triallyl isocyanurate, polybutadiene, liquid crystal polymer (LCP) of wholly aromatic polyester, fluorine resin, polyphenylene ether (PPO or PPE) And styrene-based elastomers. Polyphenylene ether (PPO or PPE) may be used in view of processability, adhesion to metals and other resin materials, dielectric properties, and low transmission loss.
As a thermosetting resin, an epoxy resin, bismaleimide resin, cyanate ester resin etc. are mentioned, for example.

  The resins contained in the insulating layer (1-I) 31 may be used alone or in combination of two or more.

  In addition, an inorganic filler, a flame retardant, and various additives may be further blended into the resin contained in the insulating layer (1-I) 31, as necessary.

«Inorganic filler»
The inorganic filler contained as necessary in the insulating layer (1-I) 31 is not particularly limited, and examples thereof include alumina, titanium oxide, mica, silica, beryllia, barium titanate and potassium titanate. Strontium titanate, calcium titanate, aluminum carbonate, magnesium hydroxide, aluminum hydroxide, aluminum silicate, calcium carbonate, calcium silicate, magnesium silicate, silicon nitride, boron nitride, clay such as calcined clay, talc, boro Acid aluminum, aluminum borate, silicon carbide and the like are used. These inorganic fillers may be used alone or in combination of two or more.
The shape of the inorganic filler is not particularly limited, and spherical or crushed inorganic fillers can be used.
The volume average particle size of the inorganic filler is not particularly limited, but may be, for example, 0.01 to 50 μm, or 0.1 to 15 μm.

  Although the compounding ratio of the inorganic filler with respect to resin is not specifically limited, For example, it can be 1-1000 mass parts with respect to 100 mass parts of total amounts of resin. When the proportion of the inorganic filler is within the above range, good adhesion can be obtained, and the toughness, heat resistance, chemical resistance, and the like of the insulating layer tend to be improved. Furthermore, from a viewpoint of suppressing thermal expansion, it can be 1-800 mass parts with respect to 100 mass parts of total amounts of resin.

  Although it does not specifically limit as a flame retardant, Flame retardants, such as a bromine system, a phosphorus system, and a metal hydroxide, are used. The flame retardants may be used alone or in combination of two or more.

  The blending ratio of the flame retardant is not particularly limited, but can be, for example, 10 to 200 parts by mass, and further 15 to 150 parts by mass with respect to 100 parts by mass of the total amount of resins. , 20 to 100 parts by mass. If the blending ratio of the flame retardant is 10 parts by mass or more, the flame resistance tends to be sufficient, and if 200 parts by mass or less, the heat resistance, the adhesiveness, the film forming ability, and the formability tend to be improved.

  Although various additives are not particularly limited, examples thereof include silane coupling agents, titanate coupling agents, heat stabilizers, antistatic agents, ultraviolet light absorbers, pigments, colorants, lubricants, and the like. These additives may be used alone or in combination of two or more.

The thickness of the insulating layer (1-I) 31 is not particularly limited, but is, for example, 10 to 300 μm, and from the viewpoint of achieving both thinning and loss reduction, it can be 20 to 250 μm. From the same point of view, it can be 30 to 200 μm.
The thickness of the insulating layer (1-I) 31 is equal to or less than the thickness of the insulating layer (1-II) 32. From the viewpoint of suppressing the warpage of the substrate, the thickness of the insulating layer (1-I) 31 is The thickness of the insulating layer (1-II) 32 can be less than that of the insulating layer (1-I) 31, and the difference between the thickness of the insulating layer (1-I) 31 and the thickness of the insulating layer (1-II) 32 suppresses warpage of the substrate. From a viewpoint, it can be set to 0 to 150 μm, and from the same viewpoint, can be 0.01 to 100 μm.

[Insulating layer (1-II) 32]
The insulating layer (1-II) 32 is a layer containing a glass cloth and a resin.
As resin, the thing similar to what is contained in insulating layer (1-I) 31 can be used.

«Glass cloth»
Although the glass cloth is not particularly limited, nonuniformities of the dielectric constant can be reduced as long as the yarn is knitted to a high density and the opened fiber yarn (opened yarn) is used. Also, if glass fiber yarns of the same kind are used for the warp and weft, the nonuniformity of the dielectric constant can be similarly reduced.
As glass fiber, E glass, S glass, NE glass, D glass, Q glass etc. can be exemplified, and it is also possible to use, for the warp and weft, glass fiber with a dielectric constant close to that of the resin to be impregnated. .

The insulating layer (1-II) 32 may be obtained by heating and / or pressing after a known prepreg is bonded alone or after bonding a predetermined number of sheets.
As a prepreg used for formation of insulating layer (1-II) 32, you may use a commercial item. Examples of commercially available prepregs include “GWA-900G”, “GWA-910G”, “GHA-679G”, “GHA-679G (S)”, and “GZA-71G” (all of which are commercial products manufactured by Hitachi Chemical Co., Ltd.) Name etc. can be used.

  The thickness of the insulating layer (1-II) 32 is not particularly limited, but is, for example, 30 to 400 μm, and from the viewpoint of achieving both thinning and loss reduction, it can be 40 to 300 μm. From the same point of view, it can be 50 to 200 μm.

(Method of Manufacturing Multilayer Transmission Line Board According to First Embodiment)
Next, a method of manufacturing the multilayer transmission line plate 1A according to the first embodiment of the present invention will be described.
The multilayer transmission line plate 1A according to the first embodiment of the present invention is, for example, provided with circuit processing on one side of a laminated plate obtained by laminating and curing copper foils on both sides of a prepreg. Forming the insulating layer (1-II) 32 on which the differential wiring 91 is disposed on the other surface and the ground layer 21 on the other surface, and then the insulating layer (1-I) 31 on the surface on which the differential wiring 91 is formed. It can manufacture by the method of laminating | stacking and shape | molding the resin film for forming, and the copper foil which comprises the grand | grand | ground layer 11 in this order.

[Prepreg]
As the prepreg for forming the insulating layer (1-II) 32, a commercially available product may be used as described above, or one obtained by a known method may be used.
The prepreg for forming the insulating layer (1-II) 32 is, for example, a resin varnish obtained by dissolving and / or dispersing the above-mentioned resin and the above-mentioned inorganic filler etc. used as required in an organic solvent Can be obtained by the method of impregnating the glass cloth.
The method for impregnating the resin varnish with the glass cloth is not particularly limited. For example, a method of immersing the glass cloth in the resin varnish, a method of applying the resin varnish to the glass cloth with various coaters, a resin varnish with the glass cloth by spraying The method of spraying etc. are mentioned. Among these, the method of immersing a glass cloth in a resin varnish can be used from a viewpoint of improving the impregnatability of a resin varnish.

[Resin film]
The resin film for forming the insulating layer (1-I) 31 can be obtained by a known method, for example, obtained by a method of forming a layer on a support after mixing the resin.
The method of mixing the resin is not particularly limited, and known methods can be used.
As a method of forming a layer on a support, for example, a resin varnish is prepared by dissolving and / or dispersing the resin in an organic solvent, and the resin varnish is applied to the support using various coaters and heated. And drying by blowing with a hot air.
The resin film obtained in this manner may be semi-cured (B-staged). The semi-cured resin film may be in a state in which an adhesive force is secured at the time of laminating and curing, and a state in which the embedding property (flowability) in the differential wiring 91 is secured.

The organic solvent used for the resin varnish is not particularly limited, but, for example, alcohols such as methanol, ethanol and butanol; ethyl cellosolve, butyl cellosolve, ethylene glycol monomethyl ether, ethers such as carbitol and butyl carbitol; acetone, methyl ethyl ketone Ketones such as methyl isobutyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene, xylene and mesitylene; esters such as methoxyethyl acetate, ethoxyethyl acetate, butoxyethyl acetate and ethyl acetate; N, N-dimethylformamide, Organic solvents such as nitrogen-containing compounds such as N, N-dimethylacetamide, N-methyl-2-pyrrolidone and the like can be mentioned. These organic solvents may be used alone or in combination of two or more.
The solid content (nonvolatile content) concentration of the resin varnish is not particularly limited, but can be, for example, 5 to 80% by mass.

  The coater used when applying the resin varnish on the support may be appropriately selected according to the thickness of the resin film to be formed, etc. For example, a die coater, a comma coater, a bar coater, a kiss coater, a roll coater etc. be able to.

The drying conditions after the resin varnish is applied on the support may be, for example, the condition that the content of the organic solvent in the resin film after drying is 10% by mass or less, and 5% by mass or less The condition that For example, a resin film can be formed by drying a varnish containing 30 to 60% by mass of an organic solvent at 50 to 150 ° C. for about 3 to 10 minutes. As the drying conditions, suitable drying conditions can be appropriately set in advance by simple experiments.
The thickness of the resin film may be appropriately determined in accordance with the thickness of the insulating layer to be formed.

The support of the resin film is, for example, a polyolefin such as polyethylene, polypropylene or polyvinyl chloride; a polyester such as polyethylene terephthalate or polyethylene naphthalate; a film made of polycarbonate or polyimide or the like; further, a release paper, copper foil, aluminum foil or the like Metal foil etc. are mentioned. In addition to the matting treatment and the corona treatment, the support and the protective film to be described later may be subjected to a releasing treatment and the like.
The thickness of the support can be, for example, 10 to 150 μm, and can be 25 to 50 μm. A protective film can be further laminated on the surface of the resin film on which the support is not provided. The protective film may be the same as or different from the material of the support. The thickness of the protective film is, for example, 1 to 40 μm. By laminating the protective film, it is possible to prevent the inclusion of foreign matter, and the resin film can be rolled up and stored.

[Lamination molding conditions]
Although the forming method and forming conditions of the multilayer transmission line plate according to the first embodiment of the present invention are not particularly limited, for example, the forming method and forming conditions of the laminated plate for electric insulating material and the multilayer plate can be applied. Specifically, using a multistage press, multistage vacuum press, continuous molding, autoclave molding machine, etc., molding at a temperature of 100 to 250 ° C., a pressure of 0.2 to 10 MPa, and a heating time of 0.1 to 5 hours. Can.
The ground layer may be formed by laminating metal foils as described above, or may be formed using a known method such as dry plating.

Holes may be formed in the insulating layer of the obtained multilayer transmission line plate to form via holes and through holes. The drilling can be performed, for example, by a known method such as a drill, laser, plasma or the like and, if necessary, in combination of these methods.
Next, a multilayer transmission line plate according to a second embodiment of the present invention will be described.

<Multilayer Transmission Line Board According to Second Embodiment>
FIG. 4 is a schematic cross-sectional view showing a multilayer transmission line plate 2A according to a second embodiment of the present invention.
As shown in FIG. 4, the multilayer transmission line plate 2A according to the second embodiment of the present invention includes a pair of ground layers 12, 22 and one of the ground layers 12 and the other of the pair of ground layers 12, 22. Differential wiring 92 disposed between layers 22, an insulating layer (2-I) 41 disposed between differential wiring 92 and one of the ground layers 12, differential wiring 92 and the other ground And the insulating layer (2-II) 42 disposed between the layer 22 and the insulating layer (2-II) 42 are laminated on the insulating layer (2-IIA) 42a and the insulating layer (2-IIA) 42a. And the insulating layer (2-I) 41 contains a glass cloth and a resin, and the insulating layer (2-IIA) 42a does not contain a glass cloth. And resin, and the insulating layer (2-IIB) 42b contains glass cloth and resin. A, the insulating layer (2-II) 42 thickness is less than or equal to the thickness of the insulating layer (2-I) 41, a multi-layer transmission line plate.

  FIG. 4 shows an example in which the insulating layer (2-IIB) 42b is disposed between the differential wiring 92 and the insulating layer (2-IIA) 42a, but the insulating layer (2-IIA) 42a May be disposed between the differential wire 92 and the insulating layer (2-IIB) 42b.

In the multilayer transmission line plate 2A according to the second embodiment of the present invention, a material not containing glass cloth is used for a part of the insulating layer which is made of the material containing glass cloth in the conventional multilayer transmission line plate. It is considered that skew can be reduced by reducing the nonuniformity of the dielectric constant.
The multilayer transmission line plate 2A according to the second embodiment of the present invention is a conventional insulating layer 62 in the conventional multilayer transmission line plate 4A shown in FIG. By changing to the insulating layer (2-II) 42 having the insulating layer (2-IIB) 42b containing the glass cloth and the resin) 42a, it is possible to reduce the skew without impairing the handleability. .
At this time, it is important that the thickness of the insulating layer (2-II) 42 be equal to or less than the thickness of the insulating layer (2-I) 41.
This is because a strong electric field is generated on the thin insulating layer side at the time of signal transmission, and thus the electrical characteristics of the insulating layer are strongly reflected by the signal transmission characteristics. That is, in order to reflect the uniformity of the dielectric constant of the insulating layer (2-IIA) 42a containing no resin and containing the resin, the insulating layer (2-II) including the insulating layer (2-IIA) 42a It is important that the thickness of the) 42 be the same as the thickness of the insulating layer (2-I) 41 containing the glass cloth and the resin, or thinner than the thickness of the insulating layer (2-I) 41.

  Resin used for the ground layers 12 and 22, the differential wiring 92, the insulating layer (2-I) 41, and the insulating layer (2-II) used for the multilayer transmission line plate 2A according to the second embodiment of the present invention The same glass cloth as that used in the multilayer transmission line plate 1A according to the first embodiment of the present invention is used.

The thickness of the insulating layer (2-I) 41 is not particularly limited, but is, for example, 40 to 400 μm, and can be 50 to 300 μm from the viewpoint of achieving both thinning and loss reduction. From the same point of view, it can be 60 to 200 μm.
The thickness of the insulating layer (2-II) 42 is not particularly limited, but is, for example, 40 to 400 μm, and can be 60 to 300 μm from the viewpoint of achieving both thinning and loss reduction. From the same point of view, it can be 80 to 200 μm.
The thickness of the insulating layer (2-IIA) 42a is not particularly limited, but is, for example, 10 to 300 μm, and from the viewpoint of achieving both thinning and loss reduction, it can be 20 to 260 μm. From the same point of view, it can be 30 to 150 μm.
The thickness of the insulating layer (2-IIB) 42b is not particularly limited, but is, for example, 30 to 390 μm, and from the viewpoint of achieving both thinning and loss reduction, it can be 40 to 280 μm. From the same point of view, it can be 50 to 170 μm.
The ratio of the thickness of the insulating layer (2-IIA) 42a to the thickness of the insulating layer (2-IIB) 42b (insulating layer (2-IIA) / insulating layer (2-IIB)) is not particularly limited. However, for example, it is 0.1 to 3.0, and from the viewpoint of achieving both thinning and loss reduction, it can be 0.3 to 2.0, and from the same viewpoint, 0.5 to 1 .8.
The thickness of the insulating layer (2-I) 41 is equal to or less than the thickness of the insulating layer (2-II) 42, and from the viewpoint of achieving both thinning and loss reduction, the thickness of the insulating layer (2-I) 41 The thickness can be less than the thickness of the insulating layer (2-II) 42, and the difference between the thickness of the insulating layer (2-I) 41 and the thickness of the insulating layer (2-II) 42 is thinner From the viewpoint of achieving both reduction and loss reduction, the thickness can be set to 0 to 150 μm, and from the same viewpoint, it can be set to 0.01 to 100 μm.

(Method of Manufacturing Multilayer Transmission Line Board According to Second Embodiment)
Next, a method of manufacturing the multilayer transmission line plate 2A according to the second embodiment of the present invention will be described.
In the multilayer transmission line plate 2A according to the second embodiment of the present invention, for example, the copper foil on one side of the laminate obtained by laminating and curing the copper foil on both sides of the prepreg is subjected to circuit processing, The insulating layer (2-IIB) 42b in which the differential wiring 92 is disposed is formed on one surface by removing the copper foil on the surface of the second surface, and then the insulating layer (2 -I) A prepreg for forming 41 and a copper foil constituting the ground layer 12 are laminated in this order, and an insulating layer is formed on the surface of the insulating layer (2-IIB) 42b opposite to the differential wiring 92. It can manufacture by the method of laminating | stacking and shape | molding the resin film for forming (2-IIA) 42a, and the copper foil which comprises the grand | ground layer 22 in this order.
The prepreg and the resin film used in the method of manufacturing the multilayer transmission line plate 2A according to the second embodiment and the lamination molding conditions thereof are the same as those of the multilayer transmission line plate 1A according to the first embodiment.

<Multilayer Transmission Line Board According to Third Embodiment>
FIG. 5 is a schematic cross-sectional view showing a multilayer transmission line plate 3A according to a third embodiment of the present invention.
As shown in FIG. 5, the multilayer transmission line plate 3A according to the third embodiment of the present invention includes a pair of ground layers 13 and 23, and one ground layer 13 and the other ground of the pair of ground layers 13 and 23. Differential wiring 93 disposed between the layer 23 and the insulating layer (3-I) 51 disposed between the differential wiring 93 and one of the ground layers 13, the differential wiring 93 and the other ground And the insulating layer (3-II) 52 disposed between the layer 23 and the insulating layer (3-II) 52, and the insulating layer (3-II) 52 is laminated on the insulating layer (3-IIA) 52a and the insulating layer (3-IIA) 52a And the insulating layer (3-I) 51 is a layer not containing glass cloth and containing a resin, and the insulating layer (3-IIA) 52a is It is a layer not containing glass cloth but containing resin, insulating layer (3-IIB) 52 Is a layer containing a glass cloth and the resin is a multilayer transmission line plate.

  FIG. 5 shows an example in which the insulating layer (3-IIB) 52b is disposed between the differential wiring 93 and the insulating layer (3-IIA) 52a, but the insulating layer (3-IIA) 52a May be disposed between the differential wire 93 and the insulating layer (3-IIB) 52b.

The multilayer transmission line plate 3A according to the third embodiment of the present invention has a dielectric constant by using a material which does not contain glass cloth in part, which is made of the material containing glass cloth in the conventional multilayer transmission line plate. It is believed that the skew can be reduced by reducing the non-uniformity of the
A multilayer transmission line plate 3A according to the third embodiment of the present invention is an insulating layer (not including glass cloth but containing resin) in the insulating layer 62 of the conventional multilayer transmission line plate 4A shown in FIG. In the insulating layer (3-II) 52 having 3-IIA) 52a and the insulating layer (3-IIB) 52b which is a layer containing glass cloth and resin, the insulating layer 61 does not contain glass cloth, By changing to the insulating layer (3-I) 51 which is a layer containing a resin, it is possible to reduce the skew without impairing the handleability.
The multilayer transmission line plate 3A according to the third embodiment of the present invention is a glass cross in any of between the differential wiring 93 and the one ground layer 13 and between the differential wiring 93 and the other ground layer 23 Since the insulating layer not containing Hb exists, the skew reduction effect can be obtained regardless of the thickness of the insulating layer (3-I) 51 and the insulating layer (3-II) 52.

  Resin used for ground layers 13 and 23, differential wiring 93, insulating layer (3-I) 51, and insulating layer (3-II) 52 used for multilayer transmission line board 3A according to the third embodiment of the present invention The same glass cloth as that used in the multilayer transmission line plate 1A according to the first embodiment of the present invention is used.

The thickness of the insulating layer (3-I) 51 is not particularly limited, but is, for example, 10 to 300 μm, and from the viewpoint of achieving both thinning and loss reduction, it can be 20 to 250 μm. From the same point of view, it can be 30 to 200 μm.
The thickness of the insulating layer (3-II) 52 is not particularly limited, but is, for example, 40 to 300 μm, and can be 60 to 250 μm from the viewpoint of achieving both thinning and loss reduction. From the same point of view, it can be 80 to 200 μm.
The thickness of the insulating layer (3-IIA) 52a is not particularly limited, but is, for example, 10 to 270 μm, and from the viewpoint of achieving both thinning and loss reduction, it can be 20 to 210 μm. From the same point of view, it can be 30 to 150 μm.
The thickness of the insulating layer (3-IIB) 52b is not particularly limited, and is, for example, 30 to 290 μm, and from the viewpoint of achieving both thinning and loss reduction, it can be 40 to 230 μm. From the same point of view, it can be 50 to 170 μm.
The ratio of the thickness of the insulating layer (3-IIA) 52a to the thickness of the insulating layer (3-IIB) 52b (insulating layer (3-IIA) / insulating layer (3-IIB)) is not particularly limited. Although it is not, from the viewpoint of achieving both thinning and loss reduction, it can be 0.2 to 3.0, and from the same viewpoint, it can be 0.3 to 2.0, and 0.5 to 0.5. It can be 1.5.

(Method of Manufacturing Multilayer Transmission Line Board According to Third Embodiment)
Next, a method of manufacturing the multilayer transmission line plate 3A according to the third embodiment of the present invention will be described.
The multilayer transmission line plate 3A according to the third embodiment of the present invention applies circuit processing to copper foil on one side of a laminate obtained by laminating and curing copper foil on both sides of a prepreg, for example, The insulating layer (3-IIB) 52b in which the differential wiring 93 is disposed is formed on one surface by removing the copper foil on the surface of the insulating layer (3). −I) A resin film for forming 51 and a copper foil constituting the ground layer 13 are laminated in this order, and the insulating layer (3-IIB) 52b is insulated on the surface opposite to the differential wiring 93. It can manufacture by the method of laminating | stacking and shape | molding the resin film for forming layer (3-IIA) 52a, and the copper foil which comprises the grand layer 23 in this order.
The prepreg and resin film used in the method of manufacturing the multilayer transmission line plate 3A according to the third embodiment, and the lamination molding conditions thereof are the same as those of the multilayer transmission line plate 1A according to the first embodiment.

  In any of the multilayer transmission line boards of the first, second and third embodiments of the present invention, the use of a low loss material can reduce the transmission loss and can further improve the signal quality.

  As mentioned above, although the suitable embodiment of the present invention was described, the present invention is not limited to the above-mentioned embodiment. The present invention can be variously modified without departing from the scope of the invention.

  Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not necessarily limited to the following examples.

Example 1
(Production of Multilayer Transmission Line Board 1A)
The multilayer transmission line board 1A shown in FIG. 3 was produced in the following procedure.
First, a laminate (made by Hitachi Chemical Co., Ltd., trade name: LW-900G) in which copper foils were formed on both sides of the insulating layer (1-II) 32 was prepared. The thickness of the insulating layer (1-II) 32 of this laminate is 130 μm, the thickness of the copper foil is 18 μm, and the conductor surface roughness (Rz) on the insulating layer (1-II) 32 side is 3.0 μm. is there.
Next, the inner layer circuit board P was formed by patterning the copper foil of one side of the said laminated board by an etching. That is, the inner layer circuit board P refers to one in which the differential wiring 91 is disposed on one surface of the insulating layer (1-II) 32, and the ground layer 21 is disposed on the other surface.

Next, the resin film for forming insulating layer (1-I) 31 was produced in the following procedure.
48 parts by mass (solid content) of 2,2-bis (4-cyanatophenyl) propane (manufactured by Lonza, trade name: BADCY), 4 parts by mass of p- (α-cumyl) phenol (manufactured by Tokyo Chemical Industry Co., Ltd.) (Solid content) and 0.008 parts by mass (solid content) of manganese naphthenate (manufactured by Wako Pure Chemical Industries, Ltd.) (solid content) were dissolved in 21 ml of toluene and heat reacted at 110 ° C. for about 3 hours.
Thereafter, the temperature is adjusted to 80 ° C., and a hydrogenated product of a styrene-butadiene copolymer (Asahi Kasei Chemicals Co., Ltd., trade name: Tuftec H1051, styrene content ratio: 42%, number average molecular weight Mn 66,000) is contained in this solution 48 mass A portion (solid content), 80 ml of toluene, and 25 ml of methyl ethyl ketone were mixed with stirring and cooled to room temperature. Then, a semi-cured resin film having a thickness of 65 μm was produced from a varnish prepared by blending 0.02 parts by mass (solid content) of zinc naphthenate (manufactured by Wako Pure Chemical Industries, Ltd.).

  Next, two of the produced resin films were stacked on the surface of the inner layer circuit board P on the differential wiring 91 side, and temporary pressure bonding was performed under the conditions of a temperature of 120 ° C., a pressure of 0.5 MPa, and a time of 40 seconds. Further, on the surface of the resin film opposite to the differential wiring 91, a copper foil having a thickness of 18 μm (made by Mitsui Mining & Smelting Co., Ltd., trade name: 3EC-VLP-18, roughened surface, which constitutes the ground layer 11) The surface roughness Rz: 3.0 μm was superposed and subjected to lamination integration treatment under conditions of temperature 230 ° C., pressure 3.0 MPa, time 80 minutes, to obtain a multilayer transmission line plate before interlayer connection.

  Subsequently, the ground layers 11 and 21 of the multilayer transmission line plate were patterned by etching to form measurement terminals. The ground pattern portion of the measurement terminal was drilled and interlayer connection was performed by electroless plating to produce a multilayer transmission line plate 1A.

Example 2
(Production of Multilayer Transmission Line Board 1B)
Example 1 and Example 1 except that the thickness of the resin film is changed to 80 μm, and the number of resin films stacked on the surface on the differential wiring 91 side of the inner layer circuit board P is changed to one. A multilayer transmission line plate 1B was produced by the same procedure.

[Example 3]
(Production of Multilayer Transmission Line Board 1C)
Example 1 and Example 1 except that the thickness of the resin film is changed to 50 μm, and the number of resin films stacked on the surface on the differential wiring 91 side of the inner layer circuit board P is changed to one. A multilayer transmission line plate 1C was produced by the same procedure.

Example 4
(Production of Multilayer Transmission Line Board 2A)
The multilayer transmission line board 2A shown in FIG. 4 was produced in the following procedure.
First, a laminate (made by Hitachi Chemical Co., Ltd., trade name: LW-900G) in which copper foils were formed on both sides of the insulating layer (2-IIB) 42b was prepared. The thickness of the insulating layer (2-IIB) 42b of this laminate is 80 μm, the thickness of the copper foil is 18 μm, and the conductor surface roughness (Rz) on the insulating layer (2-IIB) 42 b side is 3.0 μm. is there.
Next, the copper foil on one side of the laminate was patterned by etching, and the copper foil on the other side was removed by etching to form an inner layer circuit board Q. That is, the inner layer circuit board Q refers to one in which the differential wiring 92 is disposed on one surface of the insulating layer (2-IIB) 42b.

  Next, according to the same procedure as in Example 1, a 50 μm thick semi-cured resin film was produced.

  Next, one resin film was placed on the surface of the inner layer circuit board Q from which the copper foil was removed, and temporarily pressure-bonded at a temperature of 120 ° C. and a pressure of 0.5 MPa for 40 seconds. Next, a 130 μm thick prepreg (manufactured by Hitachi Chemical Co., Ltd., trade name: GWA-900G) is stacked on the surface of the inner layer circuit board Q on the differential wiring 92 side, and further, the opposite of the inner layer circuit board Q of the resin film 18 μm thick copper foil (trade name: 3EC-VLP-18, rough, made by Mitsui Mining & Smelting Co., Ltd.) which constitutes the ground layers 22 and 12 on the side of the side and the side opposite to the differential wiring 92 of the prepreg, respectively. Surface roughness Rz: 3.0 μm) was superposed and subjected to lamination integration treatment under conditions of temperature 230 ° C., pressure 3.0 MPa, time 80 minutes, and a multilayer transmission line plate before interlayer connection was produced. .

  Subsequently, the ground layers 12 and 22 of the multilayer transmission line plate were patterned by etching to form measurement terminals. The ground pattern portion of the measurement terminal was drilled and interlayer connection was performed by electroless plating to produce a multilayer transmission line plate 2A.

[Example 5]
(Production of Multilayer Transmission Line Board 2B)
A multilayer transmission line plate is prepared in the same manner as in Example 4, except that the thickness of the insulating layer (2-IIB) 42b is changed to 50 μm and the thickness of the resin film is changed to 80 μm in Example 4. 2B was made.

[Example 6]
(Production of Multilayer Transmission Line Board 2C)
A multilayer transmission line plate 2C was produced in the same manner as in Example 4 except that the thickness of the insulating layer (2-IIB) 42b was changed to 50 μm in Example 4.

[Example 7]
(Preparation of Multilayer Transmission Line Board 3A)
The multilayer transmission line plate 3A shown in FIG. 5 was produced in the following procedure.
First, a laminate (made by Hitachi Chemical Co., Ltd., trade name: LW-900G) in which copper foils were formed on both sides of the insulating layer (3-IIB) 52b was prepared. The thickness of the insulating layer (3-IIB) 52b is 80 μm, the thickness of the copper foil is 18 μm, and the conductor surface roughness (Rz) on the insulating layer (3-IIB) 52b side is 3.0 μm.
Next, the copper foil on one side of the laminate was patterned by etching, and the copper foil on the other side was removed by etching to form an inner layer circuit board R. That is, the inner layer circuit board R refers to one in which the differential wiring 93 is disposed on one surface of the insulating layer (3-IIB) 52b.

  Next, according to the same procedure as in Example 1, semi-cured resin films of 50 μm thickness and 65 μm thickness were respectively produced.

  Next, one 50 μm thick resin film is stacked on the surface of the inner layer circuit board R from which the copper foil is removed, and two 65 μm thick resin films are stacked on the surface on the differential wiring 93 side of the inner layer circuit board R. Temporary pressure bonding was performed under the conditions of 120 ° C., pressure 0.5 MPa, and time 40 seconds. Furthermore, copper having a thickness of 18 μm constituting the ground layers 23 and 13 on the surface opposite to the inner layer circuit board R of the resin film of 50 μm thickness and the surface opposite to the differential wiring 93 of the resin film of 65 μm thickness Foil (made by Mitsui Mining & Smelting Co., Ltd., trade name: 3EC-VLP-18, roughened surface roughness Rz: 3.0 μm) is superposed, and the conditions of temperature 230 ° C., pressure 3.0 MPa, time 80 minutes The laminate integration process was performed to prepare a multilayer transmission line plate before interlayer connection.

  Subsequently, the ground layers 13 and 23 of the multilayer transmission line plate were patterned by etching to form measurement terminals. The ground pattern portion of the measurement terminal was drilled and interlayer connection was performed by electroless plating to produce a multilayer transmission line plate 3A.

[Example 8]
(Production of Multilayer Transmission Line Board 3B)
A multilayer transmission line plate 3B was produced in the same manner as in Example 7 except that the thickness of the resin film temporarily crimped to the surface of the inner layer circuit board R from which copper foil was removed was changed to 80 μm in Example 7. .

[Example 9]
(Production of Multilayer Transmission Line Board 3C)
A multilayer transmission line plate 3C was produced in the same manner as in Example 7 except that the thickness of the insulating layer (3-IIB) 52b was changed to 50 μm in Example 7.

Comparative Example 1
(Production of Multilayer Transmission Line Board 4A)
The multilayer transmission line plate 4A shown in FIG. 6 was manufactured in the following procedure.
First, a laminate (made by Hitachi Chemical Co., Ltd., trade name: LW-900G) in which copper foils were formed on both sides of the insulating layer 62 was prepared. The thickness of the insulating layer 62 is 130 μm, the thickness of the copper foil is 18 μm, and the conductor surface roughness (Rz) on the insulating layer 62 side is 3.0 μm.
Next, the inner layer circuit board S was formed by patterning the copper foil on one side of the laminate by etching. That is, the inner layer circuit board S refers to one in which the differential wiring 94 is disposed on one surface of the insulating layer 62 and the ground layer 24 is disposed on the other surface.

  Next, a prepreg of 130 μm thickness (manufactured by Hitachi Chemical Co., Ltd., trade name: GWA-900G) is stacked on the surface of the inner layer circuit board S on the differential wiring 94 side, and further opposite to the differential wiring 94 of the prepreg. A 18 μm thick copper foil (Mitsui Mining & Mining Co., Ltd., trade name: 3EC-VLP-18, roughened surface roughness Rz: 3.0 μm) constituting the ground layer 14 is superimposed on the side surface Then, lamination integration processing was performed under conditions of a temperature of 230 ° C., a pressure of 3.0 MPa and a time of 80 minutes to obtain a multilayer transmission line plate before interlayer connection.

  Subsequently, the ground layers 14 and 24 of the multilayer transmission line plate were patterned by etching to form measurement terminals. The ground pattern portion of the measurement terminal was drilled and interlayer connection was performed by electroless plating to produce a multilayer transmission line plate 4A.

Comparative Example 2
(Production of Multilayer Transmission Line Board 5A)
The multilayer transmission line plate 5A shown in FIG. 7 was manufactured in the following procedure.
A multilayer transmission line plate 5A was produced in the same manner as in Example 1 except that the thickness of the insulating layer (1-II) 32 was changed to 50 μm in Example 1.

Comparative Example 3
(Production of Multilayer Transmission Line Board 6A)
A multilayer transmission line plate 6A was produced in the same manner as in Example 4 except that the thickness of the insulating layer (2-IIB) 42b was changed to 130 μm in Example 4.

[How to measure skew]
The skew of each multilayer transmission line plate obtained above was measured by the method shown below.
A 10 GHz high frequency signal is incident on the differential wiring from a network analyzer (manufactured by Keysight Technologies, Inc., trade name: N5227A) connected via a coaxial cable (made by HUBER-SUHNER, trade name: SUCOFLEX 104), and the signal is a wiring The delay time during propagation of The skew was calculated from the delay time difference between the wires.
The skew of the multilayer transmission line plate of Comparative Example 1 having the conventional structure is defined as 100%, and the ratio (%) to the skew of Comparative Example 1 is shown in Tables 1 to 3, respectively. The smaller the value is, the higher the skew reduction effect is.

  In Examples 1 to 3, in the multilayer transmission line plate 4A of Comparative Example 1 having the conventional structure, a part of the insulating layer containing the glass cloth and the resin does not contain the glass cloth but contains the resin. This is an example changed to Although Examples 1 to 3 differ in the thickness of the insulating layer, respectively, the skew is significantly reduced to 4 to 6%. It is considered that this is because the nonuniformity of the dielectric constant is greatly improved by the replacement of the material.

Comparative Example 2 is an example in which in the multilayer transmission line plate 1A of Example 1, the thickness of the insulating layer (1-II) 32 is thinner than the thickness of the insulating layer (1-I) 31. The comparative example 2 has a skew of 39%, and the skew reduction effect is lower than that of the first example.
In the multilayer transmission line plate 5A of Comparative Example 2, the electric field formed between the differential wiring 95 and the ground layers 15 and 25 is closer to the insulating layer 72 side where the distance between the differential wiring 95 and the ground layer is short. It is considered that this is because it becomes stronger and is more influenced by the material containing the glass cloth. That is, it is considered that the influence of the nonuniformity of the dielectric constant is further exerted, and as a result, the skew reduction effect is reduced.

  In Examples 4 to 6, in the multilayer transmission line plate 4A of Comparative Example 1 having the conventional structure, a layer containing a resin, not containing a glass cloth, is a part of the insulating layer 62 containing a glass cloth and a resin. It is an example changed into the insulating layer (2-IIA) 42a which is. In Examples 4 to 6, the skew is reduced to 13 to 22%. It is considered that this is because the nonuniformity of the dielectric constant is largely improved by the replacement of the material.

The comparative example 3 is an example which thickened the thickness of the insulating layer (2-IIB) 42b in the multilayer transmission line board of Examples 4-6.
As in the multilayer transmission line plate 6A of Comparative Example 3, the glass cloth is not contained but the resin is contained even when the insulating layer 82a which is a layer not containing glass cloth but containing a resin is laminated. When the thickness of the insulating layer 82 including the insulating layer 82a is larger than the thickness of the insulating layer 81, the effect of the material including the glass cloth, ie, the effect of the nonuniform layer of dielectric constant It is considered that the skew reduction effect is reduced as a result.

  In Examples 7 to 9, in the multilayer transmission line plate 4A of Comparative Example 1 having the conventional structure, a portion of the insulating layer 62, which is a layer containing glass cloth and resin, does not contain glass cloth, and resin is used. Insulating layer (3-IIA) 52a which is a layer to be contained is changed to insulating layer 61 which is a layer containing glass cloth and resin instead of insulating layer 61 which is a layer containing glass cloth and resin It is an example changed to 51). In each of Examples 7 to 9, the skew is less than 10%, and is significantly reduced. It is considered that this is because the nonuniformity of the dielectric constant is greatly improved by the replacement of the material.

  From the above measurement results, it can be seen that the multilayer transmission line board of the present invention can reduce skew in differential transmission without using a complicated process. Furthermore, all of these structures have an insulating layer containing glass cloth, and the above-mentioned effect can be obtained without impairing the handleability.

1A to 6A Multilayer Transmission Line Plates 11 to 16, 21 to 26 Ground Layer 31 Insulating Layer (1-I)
32 Insulating layer (1-II)
41 Insulating layer (2-I)
42 Insulating layer (2-II)
42a insulating layer (2-IIA)
42b Insulating layer (2-IIB)
51 Insulating layer (3-I)
52 Insulating layer (3-II)
52a Insulating layer (3-IIA)
52b Insulating layer (3-IIB)
61, 62, 72, 81, 82b Insulating layer containing glass cloth and resin 71, 82a Insulating layer containing resin but not glass cloth 91 to 96 differential wiring

Claims (1)

With a pair of ground layers,
Differential wiring disposed between one ground layer and the other ground layer of the pair of ground layers;
An insulating layer (3-I) disposed between the differential wiring and the one ground layer;
An insulating layer (3-II) disposed between the differential wiring and the other ground layer,
The insulating layer (3-II) has an insulating layer (3-IIA) and an insulating layer (3-IIB) stacked on the insulating layer (3-IIA),
The insulating layer (3-I) is a layer containing no resin and containing a resin,
The insulating layer (3-IIA) is a layer containing no resin and containing a resin,
The multilayer transmission line plate, wherein the insulating layer (3-IIB) is a layer containing a glass cloth and a resin.