JP6735185B2 - Multilayer wiring board and electronic device - Google Patents

Description

The present invention relates to a multilayer wiring board and an electronic device in which the influence of noise is reduced.

In many fields such as a wireless communication device, an imaging device, and a mobile terminal device, the signal processing speed has been greatly improved, and the need to reduce the influence of noise on the signal to be processed has also increased.

As a means for reducing the influence of noise even in a multilayer wiring board having an arithmetic element for performing high-speed signal processing, an imaging element, etc., there is, for example, a reduction in resistance of a power supply layer and a ground layer in the multilayer wiring board. As means for reducing the resistance, there are means for making the constituent materials of the power supply layer and the ground layer a material having a relatively low electric resistivity, means for increasing the thickness of the power supply layer and the ground layer, and the like.

The multilayer wiring board includes a ceramic wiring board whose insulating layer is made of a ceramic material and an organic wiring board whose insulating layer is made of an organic material. In the ceramic wiring board, in order to increase the thickness of the power supply layer and the ground layer, it is said that a so-called mesh shape or a grid shape having a large number of openings as described in Patent Document 1 is preferable. It

JP, 2000-223614, A

In order to further reduce the resistance, it is possible to further increase the thickness of the power supply layer and the ground layer. However, by increasing the thickness of the power supply layer and the ground layer, the opening becomes deep like a through hole, and the insulating layer may fall into the opening to cause unevenness on the surface of the multilayer wiring board. In addition, there is a possibility that a defective connection between the insulating layers around the opening or peeling between the layers may occur.

An object of the present invention is to provide a multilayer wiring board and an electronic device in which the influence of noise is reduced and electric characteristics are improved.

A multilayer wiring board according to one aspect of the present invention includes a flat insulating substrate made of an electrically insulating material,
A signal transmission wiring embedded in the insulating substrate for transmitting an electric signal;
A power supply layer which is embedded in the insulating substrate and to which a predetermined power supply potential is applied,
A ground layer to which a ground potential is applied, which is embedded in the insulating substrate,
At least one of the power supply layer and the ground layer is provided with a plurality of through holes penetrating in the thickness direction,
A filling member filling the plurality of through holes, further comprising a filling member having an electric resistivity larger than that of the power supply layer and the ground layer.

According to the multilayer wiring board of one aspect of the present invention, by filling the through hole provided in at least one of the power supply layer and the ground layer with a high-resistance filling member, the power supply layer and the It is possible to reduce the resistance of at least one of the ground layers, suppress surface irregularities of the multilayer wiring board, defective bonding between insulating layers and peeling between insulating layers, and reduce the influence of noise to reduce The characteristics can be improved.

It is a schematic sectional drawing which shows the multilayer wiring board 100 which is 1st Embodiment of this invention. FIG. 3 is a plan view schematically showing a power supply layer 2 and a ground layer 3. It is a schematic sectional drawing which shows the multilayer wiring board 101 which is 2nd Embodiment of this invention. It is a top view which shows 2 A of power supply layers, and the ground layer 3 typically. It is a schematic sectional drawing which shows the electronic device 200 which is 3rd Embodiment of this invention. It is a graph which shows the frequency characteristic of the impedance of the power supply layer 2 and the ground layer 3 in an Example.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a schematic sectional view showing a multilayer wiring board 100 according to a first embodiment of the present invention, and FIG. 2 is a plan view schematically showing a power supply layer 2 and a ground layer 3.

The multilayer wiring board 100 includes, for example, a rectangular flat plate-shaped insulating substrate 1, a power supply layer 2 to which a predetermined power supply potential is applied, a ground layer 3 to which a ground potential is applied, and a signal transmission wiring for transmitting an electric signal. 4 and. In the present embodiment, the power supply layer 2, the ground layer 3, and the signal transmission wiring 4 form a microstrip line, and can transmit a high frequency signal in a microwave band or a millimeter wave band, for example.

The insulating substrate 1 is formed by laminating a plurality of insulating layers 1a, 1b, 1c, 1d, and each insulating layer is made of an electrically insulating material such as a ceramic material. In this embodiment, the insulating layer 1a, the insulating layer 1b, the insulating layer 1c, and the insulating layer 1d are stacked in this order from the top. In the present embodiment, the insulating substrate 1 is configured by laminating four layers, but the present invention is not limited to this, and may be two layers, three layers, or five or more layers.

As the ceramic material, for example, an aluminum oxide sintered body, a mullite sintered body, a silicon carbide sintered body, an aluminum nitride sintered body, or a silicon nitride sintered body can be used.

The power supply layer 2 is electrically connected to an external power supply circuit or the like to give a power supply potential for supplying power to a semiconductor element described later. The power supply layer 2 is embedded in the insulating base 1, and in the present embodiment, is disposed between the insulating layer 1a and the insulating layer 1b. Further, the power supply layer 2 is provided over the entire surface of the insulating layer, except for the joint portion between the insulating layer 1a and the insulating layer 1b, that is, the outer peripheral portion for joining the insulating layers adjacent to each other, that is, a so-called solid surface. It is a pattern layer. When a through conductor is provided to electrically connect a semiconductor element to be described later and the signal transmission wiring 4, a notch or a through hole is formed in a part of the power layer 2 so that the through conductor and the power layer 2 are not short-circuited. You may provide a hole etc.

The power supply layer 2 includes a metal material that is a conductive material. When the electrically insulating material forming the insulating substrate 1 is the ceramic material as described above, the metal material forming the power supply layer 2 is a high melting point metal material that can be co-fired with the ceramic material. preferable. As the refractory metal material, for example, at least one of tungsten, molybdenum, rhenium, and tantalum can be used. Further, alloys of these refractory metal materials or alloys of these refractory metal materials with other metal materials can also be used. Further, the power supply layer 2 may be a mixture of a metal material, a glass material, and a ceramic material, which is mainly composed of a metal material in order to increase the bonding strength between the adjacent insulating layers 1a and 1b. Good.

The ground layer 3 is electrically connected to an external power supply circuit or the like to be applied with a ground potential. The ground layer 3 is embedded in the insulating base 1, and in the present embodiment, a position different from the power supply layer 2 in the thickness direction of the insulating base 1, specifically, the insulating layer 1c and the insulating layer 1d. Are disposed between the layers. In addition, the ground layer 3 is provided over the entire surface of the insulating layer, except for the joint portion between the insulating layer 1c and the insulating layer 1d, that is, the outer peripheral portion for joining the mutually adjacent insulating layers. It is a pattern layer. When a through conductor is provided to electrically connect the signal transmission wiring 4 and an external connection terminal described later, a cutout or a part of the ground layer 3 is provided so that the through conductor and the ground layer 3 are not short-circuited. A through hole or the like may be provided.

The ground layer 3 includes a metal material that is a conductive material similar to that of the power supply layer 2. That is, when the electrically insulating material forming the insulating substrate 1 is the ceramic material as described above, the metal material forming the ground layer 3 is a high melting point metal material that can be co-fired with the ceramic material. For example, at least one of tungsten, molybdenum, rhenium, and tantalum can be used. Further, alloys of these refractory metal materials or alloys of these refractory metal materials with other metal materials can also be used.

The signal transmission wiring 4 is connected to an external arithmetic circuit and a semiconductor element described later, and transmits a high frequency signal between the external and the semiconductor element. Similarly to the power supply layer 2, the signal transmission wiring 4 is also embedded in the insulating base 1, and in this embodiment, it is located at a position different from the power supply layer 2 and the ground layer 3 in the thickness direction of the insulating base 1. It is arranged between the power supply layer 2 and the ground layer 3, specifically, between the insulating layer 1b and the insulating layer 1c.

The signal transmission wiring 4 is composed of, for example, a strip-shaped conductor having a wiring width of 10 to 200 μm, a wiring thickness of 5 to 30 μm, and an interval between adjacent wirings of 50 μm or more. The high-frequency signal transmitted through the signal transmission wiring 4 varies depending on the type of the semiconductor element mounted on the multilayer wiring board 100. For example, the signal transmission wiring 4 transmits the signal in a coupled state. In the case of a pair of pair wirings or the like capable of performing the above, the signals transmitted through the respective signal transmission wirings 4 can be differential signals that are signals having opposite phases. If the signal transmitted through the signal transmission wiring 4 is a differential signal, a higher frequency signal can be transmitted.

The signal transmission wiring 4 includes a metal material that is a conductive material similar to that of the power supply layer 2. That is, when the electrically insulating material forming the insulating substrate 1 is the ceramic material as described above, the metal material forming the signal transmission wiring 4 is a high melting point metal material that can be co-fired with the ceramic material. Therefore, for example, at least one of tungsten, molybdenum, rhenium, and tantalum can be used. Further, alloys of these refractory metal materials or alloys of these refractory metal materials with other metal materials can also be used.

In the multilayer wiring board of the present invention, at least one of the power supply layer and the ground layer is provided with a plurality of through holes penetrating in the thickness direction. That is, the power supply layer and the ground layer provided with the plurality of through holes are formed in a so-called mesh or net shape. In the multilayer wiring board 100 of this embodiment, as shown in FIG. 2A, the power supply layer 2 is not provided with through holes, and as shown in FIG. Through holes 30 are provided to form the mesh-shaped ground layer 3.

The plurality of through holes 30 provided in the ground layer 3 may have a circular shape, an elliptical shape, a long hole shape, or the like in the opening shape and the cross-sectional shape, such as a triangular shape, a rectangular shape, a square shape, and a pentagonal or higher polygon. The through holes 30 may all have the same opening shape, or the through holes 30 may have different opening shapes.

The cross-sectional shape of the through hole 30 may be uniform in the thickness direction (penetration direction) of the ground layer 3 or may be different in the thickness direction. The size of the opening of the through hole 30 may be, for example, 50 to 500 μm in diameter when the opening shape is circular, and 50 to 500 μm in the case where the opening shape is square. It may be 500 μm. When the opening shape is neither circular nor square, the equivalent circle diameter (area equivalent diameter) may be within the above range.

The distribution of the plurality of through holes 30 in the plane direction of the ground layer 3 may be regular or irregular. The regular distribution is, for example, as shown in FIG. 2B, a distribution in which each through hole 30 is located on a grid point, in other words, a matrix-like distribution. Looking at the through-holes 30, the through-holes 30 are distributed in a matrix, and when looking at the conductor portions other than the through-holes 30 of the ground layer 3, the band-shaped conductors are arranged at regular intervals in the vertical and horizontal directions. The ground layer 3 has a mesh shape. The distribution of the through holes 30 is not limited to the matrix shape, and may be a houndstooth check pattern (checkered pattern) or the like.

Here, in the present invention, in order to reduce noise, the thickness of the power supply layer and the ground layer is increased to lower the electric resistance. For example, in the present embodiment, the ground layer 3 has a thickness of 10 to 30 μm. The depth (length) of the through hole 30 provided in the ground layer 3 is the same as the thickness of the ground layer 3 and is 10 to 30 μm.

Due to the manufacturing method of the insulating substrate 1 made of a ceramic material, such a deep through hole 30 causes the insulating layer before firing to largely fall into the space inside the hole. In the space inside the hole, the insulating layer 1c and the insulating layer 1d that sandwich the ground layer 3 are not partially joined, so that the insulating layer may be peeled off.

In the present invention, the through hole 30 is filled with the filling member 5 so that an unnecessary space is not formed. Filling member 5 has an electric resistivity higher than that of power supply layer 2 and ground layer 3. When the filling member 5 is made of a kind of material, the electric resistivity of the filling member 5 is the same as the electric resistivity of the material. When the filling member 5 is formed by mixing a plurality of types of materials, the electric resistivity of the filling member obtained by mixing is defined as the electric resistivity of the filling member 5.

As the material for forming the filling member 5, it is preferable to use a resistance material having a relatively high melting point and a relatively high electric resistivity so that the insulating substrate 1 made of a ceramic material can be co-fired. For example, a ruthenium-based composite oxide is used. The material may contain at least one of a substance and a metal boride. As the ruthenium-based composite oxide, for example, ruthenium oxide-calcium oxide, ruthenium oxide-strontium oxide, ruthenium oxide-barium oxide and ruthenium oxide-bismuth oxide can be used. As the metal boride, for example, lanthanum hexaboride or the like can be used. Further, like the ground layer 3 and the like, these resistance materials can be mixed with glass materials and ceramic materials. In the present embodiment, the standard of the mixing ratio of these is such that the filling member 5 has an electric resistivity of 10 to 100 times when the electric resistivity of the mesh-shaped ground layer 3 is used as a reference. And it is sufficient.

The filling member 5 may not necessarily fill the through hole 30 of the ground layer 3 and may protrude from the through hole 30. For example, the volume of the filling member 5 may be 50 to 110% based on the volume of the space inside the through hole 30.

As described above, by providing the filling member 5, even in the ground layer 3 having a large thickness and a low resistance, unevenness is generated on the surface of the multilayer wiring board 100 and the insulating layers 1c and 1d around the through hole 30. It is possible to suppress the occurrence of peeling between them.

When seen through in a plan view, the characteristic impedance may be different from the other portions in the portion where the signal transmission wiring 4 overlaps the through hole 30, and when such a portion exists in the signal transmission wiring 4, reflection of a high frequency signal to be transmitted, etc. As a result, the signal transmission characteristics are deteriorated. Therefore, it is preferable that the signal transmission wiring 4 is provided so as not to overlap the plurality of through holes 30 provided in the ground layer 3 when seen in a plan view. It is most preferable to provide the signal transmission wiring 4 so as not to overlap the through hole 30 over the entire length thereof. However, when the number of pins (the number of input/output terminals) of the semiconductor element mounted on the multilayer wiring board 100 is large, the signal transmission Since it is difficult to provide the transmission wire 4 so as not to overlap the through hole 30 at all, a part of the signal transmission wire 4 does not overlap with the through hole 30 in a plan view as long as the deterioration of the signal transmission characteristics is allowable. May overlap. For example, the signal transmission wiring 4 has a portion which does not overlap with the plurality of through holes 30 provided in the ground layer 3 in a plan view of 80% or more of the entire length. In other words, the signal transmission wiring 4 may have a portion that overlaps with the through hole 30 as long as it is less than 20% of the entire length when seen in a plan view.

In the first embodiment described above, the through hole 30 is provided only in the ground layer 3 of the power layer 2 and the ground layer 3, and the through hole 30 is filled with the filling member 5. However, the power layer 2 and the ground layer 3 are not provided. Of these, a through hole may be provided only in the power supply layer 2, and the through hole may be filled with a filling member.

FIG. 3 is a schematic sectional view showing a multilayer wiring board 101 according to a second embodiment of the present invention, and FIG. 4 is a plan view schematically showing a power supply layer 2A and a ground layer 3.

The multilayer wiring board 101 is the same as the multilayer wiring board 100 of the first embodiment except for the configuration of the power supply layer 2A, and other configurations are the same. Therefore, hereinafter, the power supply layer 2A will be mainly described and other configurations will be described. The description will be omitted.

In the multilayer wiring board 101 of the present embodiment, as shown in FIG. 4B, the ground layer 3 is provided with the through hole 30, and the through hole 30 is filled with the filling member 5. As shown in (a), the power supply layer 2A is also provided with a plurality of through holes 20, and the through holes 20 are filled with the filling member 6. According to this embodiment, not only the ground layer 3 but also the power supply layer 2A is made thicker to lower the electric resistance, so that the noise is further reduced.

For example, in this embodiment, the power supply layer 2A has a thickness of 10 to 30 μm. The depth (length) of the through hole 20 provided in the power supply layer 2A is 10 to 30 μm, which is the same as the thickness of the power supply layer 2A. The thickness of the power supply layer 2A and the thickness of the ground layer 3 may be the same or different.

Like the through holes 30 provided in the ground layer 3, the plurality of through holes 20 provided in the power supply layer 2A may have an opening shape and a cross-sectional shape such as a circular shape, an elliptical shape, and an elongated hole shape. It may have a triangular shape, a rectangular shape, a square shape, a pentagonal or more polygonal shape, and the like, all the through holes 20 may have the same opening shape, and the through holes 20 may have different opening shapes. Good. The through holes 20 and the through holes 30 may have the same opening shape or different opening shapes.

The cross-sectional shape of the through hole 20 may be uniform in the thickness direction (penetration direction) of the power supply layer 2A or may be different in the thickness direction. The size of the opening of the through hole 20 may be, for example, a diameter of 50 to 200 μm when the opening shape is circular, and a side length of 50 to 200 μm when the opening shape is square. It may be 200 μm. When the opening shape is neither circular nor square, the equivalent circle diameter (area equivalent diameter) may be within the above range.

The distribution of the plurality of through holes 20 in the surface direction of the power supply layer 2A may be regular or irregular. The regular distribution is similar to the plurality of through holes 30 of the ground layer 3, for example, a distribution in which each through hole 20 illustrated in FIG. 4A is located on a grid point, in other words, a matrix distribution. Is. Looking at the through-holes 20, the through-holes 20 are distributed in a matrix, and when looking at the conductor portions other than the through-holes 20 of the power supply layer 2A, the strip-shaped conductors are arranged at regular intervals in the vertical and horizontal directions. It is the mesh-shaped power supply layer 2A. The distribution of the through holes 20 is not limited to the matrix shape, and may be a houndstooth check pattern (checkered pattern) or the like.

In the configuration in which through holes are provided in both the power supply layer 2A and the ground layer 3 as in the present embodiment, a plurality of through holes 20 provided in the power supply layer 2A and a plurality of through holes provided in the ground layer 3 are provided. The through holes 30 may be provided so as to partially or entirely overlap with each other in plan view, or may be provided so as not to overlap. In the present embodiment, as shown in FIGS. 3 and 4, the plurality of through holes 20 provided in the power supply layer 2A and the plurality of through holes 30 provided in the ground layer 3 do not overlap with each other in plan view. Is provided.

The through hole 20 of the power supply layer 2A is filled with the filling member 6 similarly to the through hole 30 of the ground layer 3 of the first embodiment so that an unnecessary space is not formed in the through hole. Filling member 6 has an electrical resistivity higher than that of power supply layer 2 and ground layer 3. When the filling member 6 is made of a kind of material, the electric resistivity of the filling member 6 is the same as that of the material. When the filling member 6 is formed by mixing a plurality of kinds of materials, the electric resistivity of the filling member obtained by mixing is defined as the electric resistivity of the filling member 6.

As a material forming the filling member 6, a resistance material having a relatively high melting point and a high electric resistivity, specifically, the same material as the material forming the filling member 5 of the first embodiment can be used. The filling members 5 and 6 may be made of the same resistance material or different resistance materials.

The filling member 6 does not necessarily have to fill the through hole 20 of the power supply layer 2</b>A and may protrude from the through hole 20. For example, the volume of the filling member 6 may be 50 to 110% based on the volume of the space inside the through hole 20.

Also in the present embodiment, as in the first embodiment, the signal transmission wiring 4 has a plurality of through holes 30 provided in the ground layer 3 and a plurality of through holes provided with the power supply layer 2A in plan view. It is preferable to provide so as not to overlap 20. Although it is most preferable to provide the signal transmission wiring 4 so as not to overlap the through holes 20 and 30 over the entire length of the signal transmission wiring 4, a part of the signal transmission wiring 4 is a flat surface in a range where deterioration of the signal transmission characteristics is allowable. It may overlap with the through hole 20 and the through hole 30 when seen through. For example, the signal transmission wiring 4 has a portion which does not overlap with the plurality of through holes 20 provided in the power supply layer 2A and the plurality of through holes 30 provided in the ground layer 3 in a plan view of 80% or more of the entire length. doing. In other words, the signal transmission wiring 4 may have a portion that overlaps with the through hole 20 or the through hole 30 as long as it is less than 20% of the entire length in the plan view.

An example of a method of manufacturing the multilayer wiring board 100 will be described. For example, a ceramic raw material powder such as an aluminum oxide sintered body or a mullite sintered body is mixed with an appropriate organic solvent/solvent to form a slurry, which is then formed by a conventionally known doctor blade method or calendar roll method. A plurality of ceramic green sheets are obtained by adopting a sheet shape. Then, appropriate punching is performed on each of these ceramic green sheets to form via holes, and a conductive paste is filled into the via holes to form a wiring pattern for signal transmission wiring, and a solid pattern for power supply layer and ground layer. Print. At this time, at least one of the power supply layer and the ground layer is formed as a relatively thick layer by printing the layer in which the through-hole is formed a plurality of times. The through hole formed in at least one of the power supply layer and the ground layer is filled with a resistance material paste having a higher electrical resistivity than the conductor paste. It is produced by stacking the thus obtained materials and firing at a temperature of 1500 to 1700° C. for alumina ceramics and 1600 to 1900° C. for aluminum nitride ceramics.

FIG. 5 is a schematic sectional view showing an electronic device 200 according to the third embodiment of the present invention. The electronic device 200 includes a multilayer wiring board 100 and a semiconductor element 40 mounted on the multilayer wiring board 100. Since each structure of the multilayer wiring board 100 is the same as the structure described in the first embodiment, the same reference numerals as those in the first embodiment are attached and detailed description thereof will be omitted.

On the surface of the multilayer wiring board 100 on which the semiconductor element 40 is mounted, the element connection terminal 8 for electrically connecting the semiconductor element 40 and the signal transmission wiring 4 in the insulating substrate 1 is provided, An external connection terminal 9 for electrically connecting to an external circuit or the like is provided on the surface opposite to the surface on which the semiconductor element 40 is mounted. The element connection terminals 8 and the external connection terminals 9 exposed to the outside of the multilayer wiring board 100 are preferably provided with a plating layer. By providing the plating layer, the exposed surface of each terminal can be protected and oxidation can be prevented. Further, by providing the plating layer, the electrical connection with the semiconductor element 40 and the electrical connection with the external circuit can be improved. As the plating layer, for example, a Ni plating layer having a thickness of 0.5 to 10 μm may be applied. Alternatively, a gold (Au) plating layer having a thickness of 0.5 to 3 μm may be further deposited on the Ni plating layer.

The semiconductor element 40 and the element connection terminal 8 are electrically connected using, for example, a metal material such as solder or a resin material such as an anisotropic conductive film. Inside the multilayer wiring board 100, wiring for electrically connecting the element connection terminal 8 and the signal transmission wiring 4 and wiring for connecting the signal transmission wiring 4 and the external connection terminal 9 are provided, and the semiconductor element 40 is provided. And the external circuit are electrically connected via the multilayer wiring board 100.

In the present embodiment, as shown in FIG. 5, the element connection terminal 8 and the signal transmission wiring 4 are electrically connected by the penetrating conductor 7 penetrating the insulating layers 1a and 1b. The external connection terminal 9 and the external connection terminal 9 are electrically connected to each other by a through conductor 7 penetrating the insulating layer 1c and the insulating layer 1d. As described above, in order to prevent the short-circuit between the through conductor 7 and the power supply layer 2, the power supply layer 2 is provided with notches or through holes, so-called clearances, in the portions corresponding to the through conductor 7 and its periphery. Further, as described above, in order to prevent the through conductor 7 and the ground layer 3 from being short-circuited, the ground layer 3 is also provided with a clearance in the portion corresponding to the through conductor 7 and its periphery.

In the above electronic device 200, the element connection terminal 8 and the signal transmission wiring 4 are connected only by the penetrating conductor 7. However, for example, a penetrating conductor that penetrates the insulating layer 1a and a penetrating conductor that penetrates the insulating layer 1b. Is not directly connected, and a wiring or the like is provided between the insulating layer 1a and the insulating layer 1b to electrically connect the through conductor penetrating the insulating layer 1a and the through conductor penetrating the insulating layer 1b. Good. Similar to the through conductor 7, a clearance is provided in the power supply layer 2 so that such wiring does not short-circuit with the power supply layer 2. Further, the through conductor 7 that electrically connects the signal transmission wiring 4 and the external connection terminal 9 does not need to be directly connected, and penetrates the insulating layer 1c between the insulating layer 1c and the insulating layer 1d. You may provide the wiring etc. which electrically connect the penetration conductor and the penetration conductor which penetrates insulating layer 1b. Similar to the through conductor 7, a clearance is provided so that such a wiring does not short-circuit with the ground layer 3.

In the third embodiment described above, the multilayer wiring board on which the semiconductor element 40 is mounted is the multilayer wiring board 100 of the first embodiment, but the present invention is not limited to this, and the multilayer wiring board 100 is replaced by the multilayer wiring board 100 in the second embodiment. You may use the multilayer wiring board 101 of a form.

In the above embodiment, the power supply layer, the ground layer, and the signal transmission wiring are embedded in the insulating substrate 1 so that the positions in the thickness direction are different, in other words, they are embedded between different insulating layers. Although the structure of the buried position is shown as an example, the structure may be buried at the same position in the thickness direction, that is, between the same insulating layers as long as they are insulated from each other. For example, the power supply layer and the ground layer may be embedded in the insulating substrate 1 so that the positions in the thickness direction are the same, and the power supply layer and the signal transmission wiring are the same. The ground layer and the signal transmission wiring may be at the same position. Furthermore, the power supply layer, the ground layer, and the signal transmission wiring may all be embedded in the insulating base 1 at the same position in the thickness direction.

Further, in the configuration in which the power supply layer, the ground layer, and the signal transmission wiring are embedded in the insulating substrate 1 so that the positions in the thickness direction are different from each other, the thicknesses of the power supply layer, the ground layer, and the signal transmission wiring are large. The order of arrangement in the directions is not limited to the order of the power supply layer, the signal transmission signal, and the ground layer as in the above embodiment, and the order may be different. For example, the order of the power supply layer, the ground layer, and the signal transmission signal may be used, or the order of the ground layer, the power supply layer, and the signal transmission signal may be used.

Further, in the above embodiments, the configuration in which the power supply layer and the ground layer are arranged in only one layer has been shown, but the power supply layer may be two or more layers, or the ground layer may be two or more layers. A plurality of through holes may be provided in at least one of the plurality of power supply layers and ground layers, and the filling member may be filled in the through holes. Further, the signal transmission wiring is not limited to be arranged only in one layer, but may be arranged in a plurality of layers.

(Example)
Under the simulation conditions as shown below, the frequency characteristics of impedance representing the high frequency resistance of the power supply layer 2 and the ground layer 3 were calculated.
The ground layer 3 has an overall outer shape of 10 mm in length×10 mm in width and 15 μm in thickness, and the ground layer 3 has an electrical resistivity of 7.0×10 ⁻⁸ Ω·m. The through hole 30 has a square outer shape with a length of 250 μm×width of 250 μm. The power supply layer 2 was also set under the same conditions.

The distribution of the through-holes 20 and the through-holes 30 is a houndstooth pattern, and the vertical pitch is 1 mm and the horizontal pitch is 0.5 mm. The through-holes 20 and the through-holes 30 are provided so as not to overlap each other in plan view. It was The thickness of the power supply layer 2 and the ground layer 3 was 0.015 mm. The distance between the lower surface of the power supply layer 2 and the upper surface of the ground layer 3 was 0.185 mm, and an insulating layer having a relative dielectric constant of 9.8 was arranged between the lower surface of the power supply layer 2 and the upper surface of the ground layer 3. An insulating layer having a thickness of 0.1 mm and a relative dielectric constant of 9.8 was arranged above the power supply layer 2 and below the ground layer 3.

6. A hollow member in which the through hole 20 and the through hole 30 are not filled with the filling member 5 is used as a reference example, and the electric resistivity of the filling member 5 is 10 times the electric resistivity of the ground layer 3. Example 1 was set to 0×10 ⁻⁷ Ω·m, and Example 1 was set to have an electrical resistivity of 7.0×10 ⁻⁶ Ω·m, which is 100 times the electrical resistivity of the ground layer 3. It was set to 2.

FIG. 6 is a graph showing frequency characteristics of impedance of the power supply layer 2 and the ground layer 3 in the example. The vertical axis represents impedance (Ω) and the horizontal axis represents frequency (GHz). As can be seen from the graph of FIG. 5, in the vicinity of 9 GHz, the impedance of the reference example is 183 Ω, whereas in Example 1 it decreased to 151 Ω, and in Example 2 it further decreased to 81 Ω, and it is possible to lower the resistance. I understand that

1 Insulating Substrate 1a, 1b, 1c, 1d Insulating Layer 2, 2A Power Supply Layer 3 Grounding Layer 4 Signal Transmission Wiring 5, 6 Filling Member 7 Through Conductor 8 Element Connecting Terminal 9 External Connecting Terminal 20, 30 Through Hole 40 Semiconductor Element 100 , 101 Multilayer wiring board 200 Electronic device

Claims (7)

A flat insulating substrate made of an electrically insulating material,
A signal transmission wiring embedded in the insulating substrate for transmitting an electric signal;
A power supply layer which is embedded in the insulating substrate and to which a predetermined power supply potential is applied,
A ground layer to which a ground potential is applied, which is embedded in the insulating substrate,
In at least one of the power supply layer and the ground layer, a plurality of through holes penetrating in the thickness direction are provided uniformly in the surface direction ,
The multilayer wiring board further comprising: a filling member filled with the plurality of through holes, the filling member having an electric resistivity larger than that of the power supply layer and the ground layer. The multilayer wiring board according to claim 1, wherein the plurality of through holes are provided in the power supply layer and the ground layer. The power supply layer and the ground layer are embedded in different positions in the thickness direction of the insulating substrate,
The multilayer according to claim 2, wherein the plurality of through holes provided in the power supply layer and the plurality of through holes provided in the ground layer are provided so as not to overlap with each other when seen in a plan view. Wiring board. The signal transmission wiring is embedded in a position different from the power supply layer and the ground layer in the thickness direction of the insulating substrate,
In the plan view, the signal transmission wiring has a total length of 80, which is a portion which does not overlap with any of the plurality of through holes provided in the power supply layer and the plurality of through holes provided in the ground layer. % Or more is contained, The multilayer wiring board as described in any one of Claims 1-3. The power supply layer and the ground layer are configured to include at least one of tungsten, molybdenum, rhenium, and tantalum,
The multilayer wiring board according to claim 1, wherein the filling member is configured to include at least one of a ruthenium-based composite oxide and a metal boride. The multilayer wiring board according to any one of claims 1 to 5, wherein an opening shape of the plurality of through holes is a square shape or a rectangular shape. A multilayer wiring board according to any one of claims 1 to 6,
An electronic device, comprising: a semiconductor element mounted on the multilayer wiring board, the semiconductor element electrically connected to the signal transmission wiring.

Images