JP2003124633A - Multilayer wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent occurrence of ringing noise in a multilayer wiring board and occurrence of simultaneous switching noise of a circuit for power source or a circuit for ground. SOLUTION: The multilayer wiring board has a core board 5 provided with penetrating conductor 3 penetrating an insulating base body 2 and a connection land 4 stretched from the conductor 3, a multilayer wiring part constituted of a plurality of insulating layers 7 and a plurality of wiring conductor layers 8 and 9 laminated on a surface of the core board 5, and an insulating covering layer 12 formed on a surface of the multilayer wiring part. An aperture part 13 having an area larger than or equal to that of a connection land 4 is formed in a region facing the connection land 4 of the wiring conductor layer 9. Aperture parts 14 and 15 which area are smaller than or equal to that of the aperture part 13 and larger than or equal to a sectional area of the penetrating conductor 3 are formed in a region facing the aperture part 13 of the insulating layer 7 and the insulating covering layer 12. Mismatching of characteristic impedance can be prevented and occurrence of the simultaneous switching noise can be reduced.

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used for a package for housing a semiconductor element for housing a semiconductor element or an electronic circuit board on which a semiconductor element or an electronic component is mounted. The present invention relates to a multilayer wiring board, and more particularly to a multilayer wiring board having a wiring structure suitable for housing or mounting a semiconductor element operating at high speed. [0002] Conventionally, microprocessors and ASICs
(Application Specific Integrated Circuit) and other electronic components such as semiconductor elements are mounted on a multilayer wiring board used for an electronic circuit board or the like. In forming a wiring conductor for internal wiring, alumina ceramics or the like is used. The insulating layer made of ceramic and the wiring conductor layer made of a high melting point metal such as tungsten (W) are alternately laminated to form a multilayer wiring board. On the other hand, as the demand for improving the information processing capability has increased, the operating speed of the semiconductor element has been increased, and the signal wiring among the wiring conductors for the internal wiring has characteristic impedance matching and crossover between the signal wirings. There has been a demand for improvement of electrical characteristics such as reduction of talk noise. In order to cope with such a demand, the wiring structure of the signal wiring is a strip line structure, and a wide-area power supply wiring layer or a ground (ground) wiring layer is formed above and below the signal wiring via an insulating layer. Was. However, in such a multilayer wiring board, since the insulating layer is made of alumina ceramic or the like having a relative dielectric constant of about 10, the electromagnetic coupling between the signal wirings is increased, so that the crosstalk noise is increased. As a result, there has been a problem that the operation speed of the semiconductor element cannot be increased. Therefore, instead of using alumina ceramic having a relative dielectric constant of about 10 for the insulating layer, an organic material such as polyimide or epoxy resin is used for a glass epoxy resin base material having a relatively small relative dielectric constant of 3 to 5. A so-called build-up substrate formed by using such a method has come to be used. In such a build-up substrate, a conductor film for internal wiring made of copper (Cu) is formed on an insulating layer by using a thin film forming technique such as a plating method, a vapor deposition method, or a sputtering method, and the photolithography method or the like. By forming a fine pattern wiring conductor layer by etching method, by alternately laminating this insulating layer and wiring conductor layer in multiple layers,
2. Description of the Related Art Fabrication of a multi-layer wiring board having high density, high functionality, and capable of high-speed operation of a semiconductor element has been performed. In addition, as the operation speed of the semiconductor device is increased, the operation speed of the semiconductor device cannot be increased due to the mismatch of the characteristic impedance of the through conductor formed in the multilayer wiring board. Has also occurred. To cope with such a problem, Japanese Patent Application Laid-Open
A wiring structure as disclosed in JP-A-77808 has been proposed. This is one in which an opening having an area equal to or larger than the cross-sectional area of the through conductor is formed in the wiring conductor layer formed to face the through conductor. According to this method, it is possible to reduce the occurrence of characteristic impedance mismatch in the through conductor portion, and thus it is possible to suppress signal reflection. In addition, the number of signals has been increasing with the increase in the operating speed of semiconductor devices. In response to such a demand, the build-up substrate can form a fine pattern of wiring conductors, and thus has been used as a wiring substrate on which a semiconductor element operating at high speed is mounted. [0010] However, in the build-up board, since a connection land extending from a through conductor formed in a core board in the build-up board is large, Japanese Patent Laid-Open No. 2000-77808 is disclosed. In the structure as disclosed in the above, the size of the opening in the wiring conductor layer becomes large, the conductor region between the openings decreases, and the resistance value and the inductance value of the wiring conductor layer increase. Is more likely to occur. Here, simultaneous switching noise is a phenomenon in which noise occurs in a power supply or ground circuit during signal switching, and the simultaneous switching noise tends to increase as the inductance value of the power supply or ground wiring conductor layer increases. Can be seen. Therefore, in order to prevent simultaneous switching noise from increasing, it is necessary to reduce the size of the opening of the wiring conductor layer. In this case, electromagnetic coupling between the connection land and the wiring conductor layer is required. There is a problem that the characteristic impedance is reduced due to the increase, and the characteristic impedance is mismatched. As described above, the characteristic impedance mismatch locally generated in the connection land hardly causes a problem when the frequency of the propagating signal is not so high. In particular, the frequency of the signal is 1 GHz or more. When a semiconductor element that operates at a high speed is mounted, signal reflection becomes large and the problem of ringing noise occurs remarkably.
Here, the ringing noise is a phenomenon in which a signal propagated due to different characteristic impedances of a signal wiring, a through conductor, and a connection land is generated, and the reflected noise appears in the signal. SUMMARY OF THE INVENTION The present invention has been completed to solve the above problems, and an object of the present invention is to prevent simultaneous switching noise from increasing, to reduce characteristic impedance mismatching at connection lands, and to generate ringing noise. An object of the present invention is to provide a multilayer wiring board suitable for an electronic circuit board or the like on which electronic components such as semiconductor elements operating at a high speed can be reduced. According to the present invention, there is provided a multilayer wiring board comprising: an insulating base; a through conductor penetrating the insulating base;
A core substrate including a connection land extending from the through conductor on the surface of the insulating base, a multilayer wiring portion including a plurality of insulating layers and a plurality of wiring conductor layers stacked on the surface of the core substrate, An insulating covering layer formed on the surface of the multilayer wiring portion, wherein an opening having an area equal to or larger than the area of the connection land is formed in a region of the wiring conductor layer facing the connection land, and An opening having an area equal to or less than the area of the opening and having an area equal to or greater than the cross-sectional area of the through conductor is formed in a region of the layer and the insulating coating layer facing the opening. . According to the multilayer wiring board of the present invention, since the opening having the area equal to or larger than the area of the connection land is formed in the region of the wiring conductor layer opposite to the connection land, the electromagnetic connection between the connection land and the wiring conductor layer is made. Small coupling. In addition, since an opening having an area equal to or less than the area of the opening of the wiring conductor layer and having an area equal to or greater than the cross-sectional area of the through conductor is formed in a region of the insulating layer and the insulating coating layer opposite to the opening of the wiring conductor layer, Compared to the case where the opening is formed only in the insulating coating layer, the substantial relative dielectric constant between the connection land and the wiring conductor layer can be made smaller, so that the electromagnetic coupling between the connection land and the wiring conductor layer can be reduced. Can be smaller. As a result, it is possible to prevent the characteristic impedance of the connection land from lowering, so that it is possible to reduce the occurrence of mismatching of the characteristic impedance of the connection land. Therefore, occurrence of ringing noise can be reduced. Further, since the opening is formed in a region facing the opening of the wiring conductor layer for both the insulating layer and the insulating covering layer, the wiring conductor is formed in comparison with the case where the opening is formed only in the insulating covering layer. Since the characteristic impedance can be prevented from lowering even if the area of the opening formed in the layer is made smaller, the conductor region between adjacent openings formed in the wiring conductor layer becomes larger, and the resistance and inductance of the wiring conductor layer become larger. The value can be reduced, and the occurrence of simultaneous switching noise can be reduced. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a multilayer wiring board according to the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a sectional view of an essential part showing an example of an embodiment of a multilayer wiring board of the present invention, and FIG. 2 is a plan view of an essential part showing an example of a wiring conductor layer in the multilayer wiring board of the present invention. . In these figures, reference numeral 1 denotes a multilayer wiring board. Reference numeral 2 denotes an insulating base, and the insulating base 2 includes a through conductor 3
Are formed, and connection lands 4 extending from the through conductors 3 are formed on the surface of the insulating base 2, and these constitute a core substrate 5. The inside of the through conductor 3 is filled with an insulating material or a conductive material 6, a plurality of insulating layers 7 and a plurality of wiring conductor layers 8 and 9 are formed on the surface of the core substrate 5. Signal wiring through
11 is electrically connected. These plurality of insulating layers 7,
A multilayer wiring portion is formed on the surface of the core substrate 5 by the plurality of wiring conductor layers 8 and 9, the via conductor 10 and the signal wiring 11, and the outermost wiring conductor layer 9 is protected on the surface from oxidation by air. An insulating coating layer 12 is formed. The wiring conductor layers 8 and 9 are formed as wide area patterns for ground wiring or power supply wiring.
The connection land 4 is formed so as to face the wiring conductor layer 9 having a wide area pattern. Here, it is desirable that the connection land 4 be designed so that its characteristic impedance becomes, for example, 50Ω by electromagnetic coupling with the wiring conductor layer 9. When the characteristic impedance of the connection land 4 is different from the characteristic impedance of the through conductor 3 or the via conductor 10,
A mismatch in characteristic impedance causes reflection noise to occur. In the multilayer wiring board of the present invention, as shown in FIG. 1, an opening 13 having an area equal to or larger than the area of the connection land 4 is formed in a region of the wiring conductor layer 9 facing the connection land 4. As a result, electromagnetic coupling between the connection land 4 and the wiring conductor layer 9 can be reduced, so that mismatching of the characteristic impedance in the connection land 4 can be prevented. The area of the opening 13 of the wiring conductor layer 9 is
It is desirable to be as small as possible. In particular, when the openings 13 are adjacent to each other, the openings 13 are not connected to each other,
In addition, it is desirable that the area be such that the conductor region of the wiring conductor layer 9 between the openings 13 can be formed large. FIG. 4 shows a conventional multilayer wiring board.
This will be described in detail with reference to FIG. FIG. 4 is a sectional view of a main part showing an example of a conventional multilayer wiring board, and FIG. 5 is a plan view of a main part showing an example of a wiring conductor layer in the conventional multilayer wiring board. In these figures, reference numeral 51 denotes a multilayer wiring board. Reference numeral 52 denotes an insulating base, and the insulating base 52 includes a through conductor 53.
Are formed, and connection lands 54 extending from the through conductors 53 are formed on the surface of the insulating base 52, and these constitute a core substrate 55. The inside of the through conductor 53 is filled with an insulating material or a conductive material 56, a plurality of insulating layers 57 and a plurality of wiring conductor layers 58 and 59 are formed on the surface of the core substrate 55, and a via land 60 is formed on the connection land 54. Signal wiring through 61
Are electrically connected. A multilayer wiring portion is formed on the surface of the core substrate 55 by the plurality of insulating layers 57, the plurality of wiring conductor layers 58 and 59, the via conductor 60, and the signal wiring 61,
On its surface, an insulating coating layer 62 for protecting the outermost wiring conductor layer 59 from oxidation by air is formed. The wiring conductor layers 58 and 59 are formed as wide area patterns for ground wiring or power supply wiring.
The connection land 54 is formed so as to face the wiring conductor layer 59 having the wide area pattern. As shown in FIG. 4, a conventional multilayer wiring board 51
In, the connection lands 54 are covered with the insulating layer 57 and also with the insulating covering layer 62. This allows
An insulating material having a high relative dielectric constant is interposed between and around the connection land 54 and the wiring conductor layer 59, and as a result, the electromagnetic coupling between the connection land 54 and the wiring conductor layer 59 is increased, and the connection is made. The characteristic impedance of the land 54 decreases. On the other hand, as a method of improving the reduction of the characteristic impedance of the connection land 54, there is a method of increasing the size of the opening 63 formed in the wiring conductor layer 59. However, as shown in FIG. 5, when the size of the opening 63 of the wiring conductor layer 59 is increased when the connection lands 54 are formed adjacent to each other, the conductor area of the wiring conductor layer 59 between the connection lands 54 is increased. 64 is reduced, the resistance value and the inductance value of the wiring conductor layer 59 are increased, and as a result, simultaneous switching noise is likely to occur. Here, simultaneous switching noise will be described. The power supply required for the switching operation of the semiconductor element is supplied through the wiring conductor layer of the multilayer wiring board. At this time, an inductance value exists in the wiring conductor layer. This inductance has a function of obstructing power supply to the semiconductor element. In particular, when a plurality of semiconductor elements are simultaneously switched, a power supply voltage supplied to the semiconductor elements fluctuates, and noise is generated in a power supply circuit or a ground circuit. These problems become a problem particularly in a multilayer wiring board on which a semiconductor element operating at a high speed of 1 GHz or more is mounted. On the other hand, in the multilayer wiring board 1 of the present invention, as shown in FIG.
Openings 14 and 15 having an area not larger than the area of the opening 13 of the wiring conductor layer 9 and larger than the cross-sectional area of the through conductor 3 are formed in a region facing the opening 13 of the wiring conductor layer 9. Since the openings 14 and 15 formed in the insulating layer 7 and the insulating covering layer 12 are filled with air, compared with the case where the opening 14 is formed only in the conventional multilayer wiring board 51 or the insulating covering layer 12 alone. Since the substantial relative dielectric constant between the connection land 4 and the wiring conductor layer 9 is reduced and the electromagnetic coupling between the connection land 4 and the wiring conductor layer 9 is reduced, the opening formed in the wiring conductor layer 9 is reduced. Even when the size of 13 is smaller than the conventional multilayer wiring board 51, the characteristic impedance of the connection land 4 can be appropriately set to a desired value. FIG. 3 is a plan view of another embodiment of the multilayer wiring board according to the present invention, which is similar to FIG. 2, and shows a conventional multilayer wiring board 51 according to the structure of the present invention. Since the relative dielectric constant between the connection land 4 and the wiring conductor layer 9 can be substantially reduced as compared with the case where the opening 14 is formed only in the insulating coating layer 12, the connection land 4 is formed adjacently. In this case, the characteristic impedance can be prevented from lowering even if the area of the opening 13 formed in the wiring conductor layer 9 is reduced. As a result, the conductor region 16 of the wiring conductor layer 9 between the connection lands 4 is increased, and the resistance value and the inductance value of the wiring conductor layer 9 are reduced. As a result, simultaneous switching noise can be reduced. In the multilayer wiring board of the present invention, a similar wiring structure may be further laminated in multiple layers to form a multilayer wiring board. Further, a multilayer wiring board may be constructed by attaching a chip resistor, a thin film resistor, a coil inductor, a cross inductor, a chip capacitor or an electrolytic capacitor, or the like. The shapes of the insulating substrate 2 and the respective insulating layers 7 in plan view may be square, rectangular, diamond, hexagonal or octagonal. The multi-layer wiring board of the present invention includes a package for storing electronic parts such as a package for storing semiconductor elements, a substrate for mounting electronic parts, a so-called multi-chip module or multi-chip on which a large number of semiconductor elements are mounted. Used as a package or motherboard. In the multilayer wiring board of the present invention, each insulating layer 7 is made of, for example, polyimide, epoxy resin, fluororesin,
Aluminum oxide sintered body, aluminum nitride sintered body, silicon carbide based sintered body, silicon nitride based sintered body using an organic insulating material such as polynorbornene or benzocyclobutene or by a ceramic green sheet laminating method. Insulating material using inorganic insulating material such as ceramic, mullite sintered body or glass ceramic sintered body, or combining inorganic insulating powder such as ceramic powder with thermosetting resin such as epoxy resin Formed using an electrically insulating material. These insulating layers 7 are manufactured as follows. For example, in the case of an epoxy resin, the upper surface of an insulating layer made of a glass epoxy resin or the like formed by impregnating a ceramic or glass fiber woven cloth of a ceramic or a glass fiber with an epoxy resin is generally used. An insulating layer 7 made of an organic resin such as an epoxy resin formed by applying a resin precursor by a coating technique such as a spin coating method or a curtain coating method and subjecting the same to a thermosetting treatment, and copper by an electroless plating method. It is manufactured by alternately stacking thin film wiring conductor layers 8 and 9 formed by adopting a thin film forming technique such as a vapor deposition method and a photolithography technique and heating and curing at a temperature of about 170 ° C. The opening 14 of the insulating layer 7 is formed by, for example, exposing an excimer laser or C after curing if the insulating layer 7 is formed by applying and curing an epoxy resin as described above.
It is formed by a method of irradiating a laser such as an O ₂ gas laser. At this time, the opening 14 may be formed every time one insulating layer 7 is formed, or may be formed at a time after laminating a desired number of insulating layers 7 or after forming the insulating coating layer 12 thereon. You may. When the insulating layer 7 is made of a photosensitive material, the opening 14 is formed simultaneously with the through hole for forming the insulating layer 7 and the through conductor 3. For example, when the insulating layer 7 is formed of photosensitive polyimide, a photosensitive polyimide resin is applied by a spin coating method or the like, and a portion to be a through hole or an opening 14 is masked and irradiated with ultraviolet light or the like to penetrate. After hardening the resin other than the hole or the opening 14, the resin can be formed by removing the resin in the through hole or the opening 14. When the insulating layer 7 is made of, for example, an aluminum oxide sintered body, first, an appropriate organic binder, a solvent or the like is added to a raw material powder such as aluminum oxide, silicon oxide, calcium oxide or magnesium oxide. A ceramic green sheet is obtained by mixing to form a slurry and forming the sheet into a sheet by employing a conventionally known doctor blade method. An appropriate punching process is performed on the ceramic green sheet to form a through hole in which the opening 14 and the through conductor 3 are formed. Then, a metal paste to be the through conductor 3 is printed and embedded in the through hole, a metal paste to be each of the wiring conductor layers 8 and 9 is printed and applied in a predetermined pattern, and is stacked vertically. It is manufactured by firing at a temperature of about 1600 ° C. The thickness of the insulating layer 7 is appropriately set according to the characteristics of the material to be used so as to satisfy conditions such as mechanical strength and electrical characteristics corresponding to required specifications. The insulating coating layer 12 is formed by the same method using the same material as that for forming the insulating layer 7. At that time, the insulating layer 7 formed in the outermost layer in a predetermined shape can be used as the insulating coating layer 12. Further, after forming the insulating layer 7, the insulating coating layer 12 may be formed using a material different from the insulating layer 7, for example, by applying and curing an epoxy resin solder resist in a predetermined shape, or It may be formed by applying a solder resist made of a photosensitive epoxy resin on the entire surface, irradiating it with ultraviolet light or the like through a mask having a predetermined shape, and curing it, and removing unnecessary uncured portions. When the insulating layer 7 is made of, for example, a sintered body of aluminum oxide, the outermost layer of the ceramic green sheet on which a predetermined pattern is formed by the metal paste in the method of forming the insulating layer 7 described above. By forming the insulating coating layer 12 in a predetermined pattern on the ceramic green sheet to be formed using a paste having the same components as the ceramic green sheet, the insulating coating layer 12 is formed simultaneously with the insulating layer 7. When the insulating coating layer 12 is formed as described above, the opening of the insulating coating layer 12 is formed simultaneously with the formation of the insulating coating layer 12.
15 are also formed. Each wiring conductor layer 8 is made of, for example, tungsten (W), molybdenum (Mo), molybdenum manganese (Mo-Mn), copper (Cu), silver (Ag), or silver palladium (Ag-Pd). Metal powder metallization or thin film of metal material such as copper (Cu), silver (Ag), nickel (Ni), chromium (Cr), titanium (Ti), gold (Au) or niobium (Nb) or alloys thereof May be formed. Specifically, for example, in the case of forming a thin film of a metal material, after forming a metal film by a sputtering method, a vacuum evaporation method or a plating method, it can be formed into a predetermined wiring pattern by a photolithography method. On the other hand, when the metal powder of W is formed by metallization, a metal paste obtained by adding and mixing an appropriate organic binder, a solvent and the like to the W powder is printed in a predetermined pattern on a ceramic green sheet serving as the insulating layer 7. It can be formed by coating and firing this together with the laminate of ceramic green sheets. It should be noted that the present invention is not limited to the above-described embodiment, and various changes may be made without departing from the spirit of the present invention. According to the present invention, there is provided a multilayer wiring board comprising: a core substrate having a through conductor penetrating the insulating base; a connection land extending from the through conductor on the surface of the insulating base; A multi-layer wiring portion including a plurality of insulating layers and a plurality of wiring conductor layers laminated on the surface of the substrate, and an insulating coating layer formed on the surface of the multi-layer wiring portion, facing a connection land of the wiring conductor layer; An opening having an area equal to or larger than the area of the connection land is formed in the area to be formed, and an area not larger than the area of the opening is equal to or larger than the area of the opening in the area facing the opening of the insulating layer and the insulating coating layer. Is formed. According to the multilayer wiring board of the present invention, since the opening having the area equal to or larger than the area of the connection land is formed in the area of the wiring conductor layer facing the connection land, the electromagnetic connection between the connection land and the wiring conductor layer is made. Small coupling. In addition, since an opening having an area equal to or less than the area of the opening of the wiring conductor layer and having an area equal to or greater than the cross-sectional area of the through conductor is formed in a region of the insulating layer and the insulating coating layer opposite to the opening of the wiring conductor layer, Compared to the case where the opening is formed only in the insulating coating layer, the substantial relative dielectric constant between the connection land and the wiring conductor layer can be made smaller, so that the electromagnetic coupling between the connection land and the wiring conductor layer can be reduced. Can be smaller. As a result, since a decrease in the characteristic impedance of the connection land can be prevented, the occurrence of a mismatch in the characteristic impedance of the connection land can be reduced. Therefore, occurrence of ringing noise can be reduced. Further, since the opening is formed in the region opposite to the opening of the wiring conductor layer in both the insulating layer and the insulating coating layer, the wiring conductor is formed in comparison with the case where the opening is formed only in the insulating coating layer. Even if the area of the opening formed in the layer is made smaller, the characteristic impedance can be prevented from lowering.
The conductor area between adjacent openings formed in the wiring conductor layer becomes larger, the resistance value and the inductance value of the wiring conductor layer are reduced, and the occurrence of simultaneous switching noise can be reduced. As a result, according to the multilayer wiring board of the present invention, simultaneous switching noise is prevented from increasing, and mismatching of characteristic impedance at connection lands is reduced.
It is possible to provide a multilayer wiring board suitable for an electronic circuit board or the like on which electronic components such as a semiconductor element operating at a high speed can be mounted and which can reduce the occurrence of ringing noise.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view of a principal part showing an example of an embodiment of a multilayer wiring board of the present invention. FIG. 2 is a main part plan view showing an example of a wiring conductor layer in the multilayer wiring board of the present invention. FIG. 3 is a main part plan view showing another example of the wiring conductor layer in the multilayer wiring board of the present invention. FIG. 4 is a sectional view of a main part showing an example of a conventional multilayer wiring board. FIG. 5 is a plan view of a main part showing an example of a wiring conductor layer in a conventional multilayer wiring board. [Description of Signs] 1: Multilayer wiring board 2: Insulating base 3: Through conductor 4: Connection land 5: Core substrate 7: Insulating layers 8, 9: Wiring conductor layer 12: Insulating coating layer 13: (of the wiring conductor layer) Opening 14: Opening (of insulating layer) 15: Opening (of insulating coating layer)

   ────────────────────────────────────────────────── ─── Continuation of front page    F term (reference) 5E317 AA24 BB04 BB12 BB13 BB14                       BB16 BB17 CC25 CD27 CD32                       GG11                 5E346 AA02 AA06 AA12 AA15 AA22                       AA32 AA43 AA51 BB01 BB11                       BB16 CC16 CC32 CC35 CC36                       CC38 CC39 DD34 EE31 FF01                       FF18 FF45 GG05 GG06 GG15                       HH01 HH03 HH04 HH06

Claims (1)

1. A core substrate comprising: an insulating base; a through conductor penetrating the insulating base; and a connection land extending from the through conductor on a surface of the insulating base; A multilayer wiring portion including a plurality of insulating layers and a plurality of wiring conductor layers laminated on the surface of the core substrate, and an insulating coating layer formed on the surface of the multilayer wiring portion; An opening having an area equal to or greater than the area of the connection land is formed in a region facing the land, and the area of the insulating layer and the insulating coating layer facing the opening is equal to or less than the area of the opening, and A multilayer wiring board, wherein an opening having an area equal to or larger than a cross-sectional area of the through conductor is formed.