JP6224525B2 - Wiring board and electronic device - Google Patents

Description

  The present invention relates to a wiring board and an electronic device having connection pads for electrical connection with the outside.

  As a wiring board on which electronic components such as semiconductor elements are mounted, an insulating substrate made of a glass ceramic sintered body and the like, and an external connection provided on the main surface of the insulating substrate using a metal material such as copper or silver A thing including a plurality of connection pads is often used.

  For example, an electronic component is mounted on the main surface opposite to the main surface on which the connection pads of the insulating substrate are provided, and the connection pads are connected to a predetermined portion of the external electric circuit. The electronic component mounted on the mounting portion is electrically connected to the connection pad via a wiring conductor provided from the mounting portion to the connection pad. If the connection pad and the external electric circuit are connected by solder or the like, the electronic component and the external electric circuit are electrically connected to each other through the connection pad.

  The connection pads are made of a metal material such as copper, which has a circular pattern or the like and is deposited on the main surface of the insulating substrate in the form of a metallized layer or the like. In addition, these connection pads are arranged vertically and horizontally on the main surface of the insulating substrate. The plurality of connection pads arranged include those that are electrically connected to the signal electrodes of the electronic component and those that are electrically connected to the grounding electrode.

Japanese Patent Laid-Open No. 2001-160598

  In recent years, with the increase in the frequency of electrical signals transmitted between wiring boards and electronic components, for example, electromagnetic shields and relatively large ground conductor layers are placed inside insulating boards to stabilize power supply voltages. May be. In this case, an unnecessary parasitic capacitance is generated between the signal connection pad and the ground conductor layer, and there is a problem that characteristic impedance mismatch is likely to occur in the connection pad. To deal with such a problem, for example, the area (size in a bottom view) of the connection pad electrically connected to the signal electrode is smaller than that electrically connected to the ground electrode. A means of suppressing the parasitic capacitance can be considered.

  However, when the area of the connection pad is kept small, the bonding area of the connection pad to the insulating substrate is relatively small. For this reason, a problem that the strength of bonding between the connection pad and the insulating substrate is likely to be lowered is newly induced. Further, when the area of the connection pad is different between the signal pad and the ground pad, there is a problem that it is difficult to connect to an external electric circuit by solder or the like.

A wiring board according to one aspect of the present invention is arranged on an insulating substrate having a first main surface, and the first main surface of the insulating substrate, and includes at least one signal pad conductor and the signal pad conductor. A plurality of pad conductors including at least one adjacent ground pad conductor; and a covering layer covering the first main surface of the insulating substrate from the outer periphery of each of the plurality of pad conductors. doing. A plurality of connection pads including at least one signal pad and at least one ground pad adjacent to the signal pad by an exposed portion inside the outer peripheral portion covered with the coating layer among the plurality of pad conductors. In the plan view, the ground pad conductor is larger than the signal pad conductor, and the signal pad and the ground pad have the same size.

  An electronic device according to an aspect of the present invention includes the wiring board having the above-described configuration and an electronic component mounted on a second main surface opposite to the first main surface of the insulating substrate.

  According to the wiring board according to one aspect of the present invention, since it has the above configuration, the parasitic capacitance generated in the signal pad conductor is reduced as compared with the related art. That is, the parasitic capacitance is reduced in the signal pad formed by covering the outer periphery of the signal pad conductor. In addition, since the outer peripheral portion of the signal pad conductor is covered with the coating layer, the strength of bonding to the insulating substrate as the signal pad is also improved. In addition, since the signal pad and the ground pad are the same size, connection to an external electric circuit is easy. Therefore, it is possible to provide a wiring board that facilitates the manufacture of an electronic device with high matching reliability for characteristic impedance matching and external electric circuit.

  According to the electronic device according to one aspect of the present invention, since the wiring board having the above-described configuration and the electronic component mounted on the wiring board are included, matching of characteristic impedance and mounting reliability with respect to an external electric circuit are provided. A high electronic device can be provided.

(A) is a top view which shows the principal part in the wiring board of embodiment of this invention, (b) is sectional drawing in the AA of (a). (A) is a top view which shows an example of the whole wiring board shown in FIG. 1, and the electronic device containing the wiring board, (b) is a side view of (a). (A) And (b) is a top view which shows the modification of the wiring board and electronic device which are respectively shown in FIG. (A) And (b) is a top view which shows the other modification of the wiring board and electronic device which are respectively shown in FIG.

  The wiring board and electronic device of the present invention will be described with reference to the accompanying drawings. Fig.1 (a) is a top view which shows the principal part in the wiring board of embodiment of this invention, FIG.1 (b) is sectional drawing in the AA line of Fig.1 (a). 2A is a plan view showing an example of the entire wiring board shown in FIG. 1 and an electronic device including the wiring board, and FIG. 2B is a side view of FIG. 2A. . An electronic component 21 is mounted on a wiring board 10 whose main part is shown in FIG. 1, and for example, an electronic device 20 as shown in FIG. 2 is formed. This electronic device 20 is mounted on an external substrate (not shown) including, for example, an external electric circuit (not shown). Note that FIG. 1A is not a cross-sectional view, but is partially hatched for easy identification.

  In the example shown in FIGS. 1 and 2, the wiring substrate 10 includes an insulating substrate 1 having a first main surface, a plurality of pad conductors 2 provided on the first main surface of the insulating substrate 1, and an insulating substrate 1. And a covering layer 3 that covers the outer periphery of each of the plurality of pad conductors 2 from the first main surface. For each of the plurality of pad conductors 2, a portion exposed on the inner side of the outer peripheral portion covered with the coating layer is a connection pad 4.

Further, the electronic device 21 is basically formed by mounting the electronic component 21 on the second main surface of the wiring substrate 10 opposite to the first main surface of the insulating substrate 1. The electronic component 21 mounted on the second main surface is electrically connected to the pad conductor 2 by, for example, an internal conductor 5 provided from the second main surface of the insulating substrate 1 through the inside to the pad conductor 2. . A ground conductor layer 6 is provided in a relatively wide area in the insulating substrate 1 for, for example, electromagnetic shielding with respect to the inner conductor 5 and the like, stabilization of power supply voltage (reduction of power supply impedance), and adjustment of characteristic impedance. It has been.

  Of the pad conductor 2, the portion of the connection pad 4 is connected to the external electric circuit via the conductive connecting material 7, and the electronic component 21 and the external electric circuit are electrically connected to each other.

  In the example of FIGS. 1 and 2, the first main surface of the insulating substrate 1 is the lower surface, and the second main surface is the upper surface.

  The insulating substrate 1 has, for example, a quadrangular shape (square plate shape or the like) in plan view, and the first main surface is mounted to face an external electric circuit (external substrate). In addition, the electronic component 21 is mounted on the second main surface, for example, at the center thereof. In this case, the central portion of the second main surface functions as a mounting portion for the electronic component 21. In this case, connection pads (not shown) for electrical connection with the electronic component 21 are also formed in the mounting portion. This connection pad may have the same form as the connection pad 4 on the first main surface.

  Examples of the electronic component 21 include semiconductor integrated circuit elements such as IC and LSI, semiconductor elements including optical semiconductor elements such as LED (light emitting diode), PD (photodiode) and CCD (charge coupled device), surface acoustic wave elements, and the like Examples include a piezoelectric element such as a crystal resonator, a capacitive element, a resistor, and a micromachine (a so-called MEMS element) in which a minute electromechanical mechanism is formed on the surface of a semiconductor substrate.

  When the electronic component 21 is a semiconductor integrated circuit element such as an LSI, the number of electrodes of the electronic component 21 is larger than that of other electronic components. Therefore, the number of pad conductors 2 electrically connected to these is also particularly large and tends to be arranged on the first main surface of the insulating substrate 1 with a high density. In addition, the frequency of electrical signals transmitted through the pad conductor 2 and the internal conductor 5 is increasing. Further, semiconductor integrated circuit elements tend to be larger (for example, about 30 mm square).

The insulating substrate 1 is formed of an insulating material such as a glass ceramic sintered body, an aluminum oxide sintered body, a mullite sintered body, or an aluminum nitride sintered body. The insulating substrate 1 may be formed by laminating a plurality of insulating layers made of such an insulating material. When the insulating substrate 1 is formed by laminating a plurality of insulating layers made of a glass ceramic sintered body, the insulating substrate 1 can be manufactured as follows. First, ceramic filler powder is prepared. Examples of the ceramic filler powder include aluminum oxide, chromium oxide, copper oxide, zirconium oxide, spinel and quartz. Moreover, a glass powder is prepared. Examples of the glass powder include SiO ₂ —B ₂ O ₃ —Al ₂ O ₃ —MgO—CaO—BaO—SrO-based glass. An appropriate organic binder and organic solvent are added to and mixed with the raw material powder containing these ceramic filler powder and glass powder to prepare a slurry. Next, a plurality of ceramic green sheets are produced by forming this slurry into a sheet by employing a sheet forming technique such as a doctor blade method or a lip coater method. Thereafter, the ceramic green sheet is made into an appropriate shape by a processing method selected from cutting and punching and the like, and a plurality of these are laminated. The insulating substrate 1 can be manufactured by baking at a temperature.

  The insulating substrate 1 may be made of a composite material containing an organic resin. In this case, for example, the insulating substrate 1 can be manufactured by molding and curing an uncured organic resin material (thermosetting resin) into a predetermined shape of the insulating substrate 1 using a mold or the like.

  The pad conductor 2 is a part including a connection pad 4 for electrically connecting the electronic component 21 and an external electric circuit. An inner portion of the pad conductor 2 exposed from the opening of the coating layer 3 is a connection pad 4. Details of the coating layer 3 will be described later.

  The part of the electronic component 21 that is actually electrically connected to the pad conductor 2 includes a signal electrode and a ground electrode. Therefore, the pad conductor 2 includes a signal pad conductor 2a and a ground pad conductor 2b. The signal pad conductor 2a is electrically connected to the signal electrode of the electronic component, and the ground pad conductor 2b is electrically connected to the ground electrode of the electronic component. The ground pad conductor 2b is electrically connected to the ground conductor layer 6 as in the example of FIG.

  The pad conductor 2 is a circular pattern in the examples of FIGS. 1 and 2, but other patterns, for example, an elliptical shape, a circular shape with a part of the outer peripheral portion missing, or a polygonal shape may be used. Absent.

  The pad conductor 2 is made of, for example, a metal material such as copper, silver, palladium, gold, platinum, tungsten, molybdenum, or manganese, or an alloy material containing these metal materials as a main component. Further, the pad conductor 2 may contain an inorganic material such as glass in addition to these metal materials. These metal materials and the like are provided on the insulating substrate 1 in the form of, for example, a metallized layer, a plating layer, a vapor deposition layer, or the like.

  If the pad conductor 2 is made of, for example, a copper metallized layer, a metal paste prepared by kneading copper powder together with an organic solvent and a binder is used as the first main surface of the ceramic green sheet to be the insulating substrate 1. It can form by apply | coating to the surface used as a predetermined pattern, and baking simultaneously. The metal paste can be applied by a printing method such as a screen printing method.

  Further, a metal material such as copper is deposited on the first main surface of the insulating substrate 1 made of the organic resin material as described above by means such as vapor deposition or plating to form the pad conductor 2. May be.

  The covering layer 3 covers the outer periphery of the pad conductor 2 to form the connection pad 4. As described above, the outer peripheral portion of the pad conductor 2 is covered with the coating layer 3, and the central portion is exposed. As described above, the exposed portion is the connection pad 4. The covering layer 3 improves the bonding strength of the outer peripheral portion of the pad conductor 2 to the insulating substrate 1. Moreover, the coating layer 3 can also be regarded as a part for having the function to adjust the part which actually functions as the connection pad 4 among the pad conductors 2 to a desired shape and size.

  The covering layer 3 is made of, for example, a ceramic material similar to that of the insulating substrate 1. In this case, first, an unfired ceramic paste having the same composition as that of the insulating substrate 1 is prepared. Next, this ceramic paste is applied so as to cover from the surface of the ceramic green sheet (the surface to be the first main surface) to the outer periphery of the metal paste to be the pad conductor 2 applied to the surface, and thereafter Bake. The coating layer 3 can be formed by the above process.

  The covering layer 3 may be a ceramic material having a composition different from that of the insulating substrate 1 or a glass material, or may be made of the same organic resin material as that of the insulating substrate 1.

  The connection pad 4 formed by covering the outer periphery of the pad conductor 2 with the coating layer 3 includes a signal pad 4 a and a ground pad 4 b, as with the pad conductor 2. The signal pad 4 a is electrically connected to the signal electrode of the electronic component 21, and the ground pad 4 b is electrically connected to the ground electrode of the electronic component 21.

  The connection pad 4 is a part for external connection as described above, and is directly connected to a predetermined portion of the external electric circuit by, for example, the conductive connection material 7 such as a solder bump. In this case, the connection pad 2 and the predetermined part of the external electric circuit are positioned to face each other via the solder bump. Thereafter, the solder bumps are heated and melted once and then cooled and solidified, whereby the connection pads 4 and the external electric circuit are joined to each other and electrically connected.

  Among the plurality of connection pads 4, the ground pad 4b is disposed adjacent to the signal pad 4a for electromagnetic shielding against a signal transmitted to the signal pad 4a and characteristic impedance matching in the signal pad 4a and the like. ing. In other words, since at least one ground pad 4b (ground pad conductor 2b) is disposed adjacent to the signal pad 4a, the effect of electromagnetic shielding on the signal pad 4a (signal pad conductor 2a) and the like, and The effect of characteristic impedance matching is obtained.

  Further, in a plan view (when seen through from the first main surface side), the ground pad conductor 2b is larger than the signal pad conductor 2a, and the signal pad 4a and the ground pad 4b have the same size (hereinafter, referred to as the following). In some cases, the size may be simply referred to by omitting the plan view). Since the size of the signal pad conductor 2a is relatively small, the area where the signal pad conductor 2a and the ground conductor layer 6 face each other with a part of the insulating substrate 1 therebetween is suppressed to be small. For this reason, the parasitic capacitance generated between the signal pad conductor 2a and the ground conductor layer 6 is relatively small. Therefore, characteristic impedance mismatch due to unnecessary parasitic capacitance is suppressed. In other words, it is easy to match the characteristic impedance of the signal pad conductor 2a. Further, since the distance between the signal pad conductor 2a and the ground pad conductor 2b is relatively small, the parasitic capacitance generated between the signal pad conductor 2a and the ground pad conductor 2b is relatively small.

  Further, since the outer peripheral portion of the signal pad conductor 2a is covered with the covering layer 3, the strength of bonding to the insulating substrate 1 as the signal pad 4a is also improved. Further, since the signal pad 4a and the ground pad 4b have the same size, the amount of the conductive connecting material 7 suitable for joining each of the signal pad 4a and the ground pad 4b to the external electric circuit is approximately the same. Become. Therefore, connection to an external electric circuit is easy. Therefore, it is possible to provide the wiring board 10 that facilitates the manufacture of the electronic device 20 with high matching of characteristic impedance and high mounting reliability with respect to the external electric circuit.

  The signal pad 4a and the ground pad 4b having the same size means that the shape and area of the signal pad 4a and the ground pad 4b are the same in plan view (when viewed from the first main surface side). To do.

  Further, according to the electronic device 20 of the above-described embodiment, since the wiring board 10 having the above-described configuration and the electronic component 21 mounted on the wiring board 10 are provided, matching of characteristic impedance and the external electric circuit are performed. The electronic device 20 with high mounting reliability can be provided. If the electronic component 21 is a semiconductor integrated circuit element, an electronic device (semiconductor device) with high reliability of operation of the electronic component 21 and high reliability of mounting on an external substrate such as a printed circuit board (so-called secondary mounting) 20 will be provided.

  In the wiring board 10 and the electronic device 20 of the above embodiment, the signal pad 4a and the ground pad 4b do not necessarily have exactly the same shape and area as each other, and are a metal paste or a coating layer serving as a pad conductor 3. A deviation (deviation from a state that is exactly the same) or the like caused by processing accuracy at the time of manufacture, such as printing accuracy of the ceramic paste No. 3 is allowed. As this deviation, for example, when the signal pad 4a and the ground pad 4b are circular with respect to each other, the difference in area between the two is about 5% or less.

  Further, in the example of FIG. 1, one signal pad conductor 2a is surrounded by a plurality of ground pad conductors 2b. In this case, it is easier to adjust the characteristic impedance of the signal pad 2a.

  In addition, when a plurality of ground pad conductors 2b surrounding the signal pad conductor 2a have the same distance between the signal pad conductor 2a and the ground pad conductor 2b, the characteristic impedance of the signal pad conductor 2a is as follows. Is easier to adjust.

  In the example of FIG. 1B, the outer periphery of the pad conductor 2 covered with the coating layer 3 enters the inside of the insulating substrate 1. The portion of the pad conductor 2 that enters the inside of the insulating substrate 1 penetrates deeper into the inside of the insulating substrate 1 as it is closer to the outer periphery of the pad conductor 2. That is, the outer periphery of the pad conductor 2 is inclined toward the inside of the insulating substrate 1, and the inclined portion is located inside the insulating substrate 1. As a result, the outer peripheral portion of the pad conductor 2 that tends to be a starting point of peeling from the insulating substrate 1 due to thermal stress is more firmly bonded to the insulating substrate 1 by the anchor effect or the like. Therefore, the connection reliability with respect to the external electric circuit is improved.

  In order to allow the outer peripheral portion of the pad conductor to enter the inside of the insulating substrate 1, for example, the following may be performed. That is, after sequentially printing the metal paste to be the pad conductor 2 and the ceramic paste to be the coating layer 3 on the ceramic green sheet to be the insulating substrate 1, the printed portion of the ceramic paste is placed in the thickness direction of the ceramic green sheet or the like. Pressurize. The outer periphery of the metal paste enters the ceramic green sheet by pressurization.

  In this case, since the outer peripheral portion of the pad conductor 2 is inclined, the inclined outer peripheral portions of the signal pad conductor 2a and the ground pad conductor 2b adjacent to each other are separated from each other by the insulating substrate 1. The areas facing each other with a part in the thickness direction of (and coating layer 3) interposed therebetween are further increased. Therefore, the parasitic capacitance tends to increase between the signal pad conductor 2a and the ground pad conductor 2b adjacent to each other. On the other hand, since the signal pad conductor 2a is relatively small as described above, the effect of suppressing an increase in parasitic capacitance is great.

  When both the signal pad conductor 2a and the ground pad conductor 2b are circular, the area of the ground pad conductor 2b with respect to the area of the signal pad conductor 2a is set to about 110 to 130%, for example.

  In addition, the connection pad 4 (signal pad 4a and ground pad 4b) has a reliability of connection with an external electric circuit through the conductive connection material 7 such as a solder bump, and workability at the time of connection. A circular shape is preferred. When the connection pad 4 has a circular shape, for example, the outer peripheral portion of the circular pad conductor 2 is covered with the coating layer 3 with the same width over the entire periphery.

  3A and 3B are plan views showing modifications of the wiring board and the electronic device shown in FIG. 2, respectively. 3, parts similar to those in FIG. 2 are denoted by the same reference numerals.

In the example of FIG. 3A, the signal pads 4a among the connection pads 4 arranged in the vertical and horizontal directions are arranged on the center side, avoiding the outermost periphery of the arrangement. In the outermost array of the connection pads 4, the thermal stress due to the difference in thermal expansion coefficient between the insulating substrate 1 and the external substrate is particularly large. The signal pad conductor 2a (that is, the signal pad 4a) having a relatively small bonding area between the pad conductor 2 and the insulating substrate 1 is not disposed in the portion where the thermal stress is large. In other words, only the pad conductor 2 having a relatively large bonding area with the insulating substrate 1 is disposed in a portion where the thermal stress is large. Therefore, it is possible to provide the wiring substrate 10 and the electronic device 20 that are more effective in improving the reliability of external connection as the wiring substrate 10 and the electronic device 20.

  In this example, the signal pad conductors 2a (signal pads 4a) are arranged so as not to be adjacent to each other in the vertical or horizontal direction of the arrangement. Therefore, the adjacent interval between the signal pads 4a can be made relatively large. Therefore, suppression of electromagnetic interference between electrical signals transmitted through the signal pad 4a is also effective.

  In the example of FIG. 3B, the signal pad conductor 2 a located at the outermost periphery of the array is covered with the covering layer 3 with a relatively wide width at the portion facing the outer periphery of the lower surface of the insulating substrate 1. Yes. That is, the outermost signal pad conductor in the array has a circular shape with the outer side partially protruding outward on the outer peripheral side of the lower surface of the insulating substrate 1. The signal pad conductor 2a can be regarded as a circular pattern whose radius changes midway in the circumferential direction.

  In such a case, a larger bonding area between the signal pad conductor 2a and the insulating substrate 1 is secured on the outer peripheral side of the lower surface of the insulating substrate 1 where the thermal stress acts relatively large. Therefore, also in this case, it is possible to provide the wiring substrate 10 and the electronic device 20 that are more effective in improving the reliability of the external connection as the wiring substrate 10 and the electronic device 20.

  Further, since the signal pad conductor 2a is smaller than the ground pad conductor 2b, the parasitic capacitance between the signal pad conductor 2a and the ground conductor layer 6 is also relatively small. For this reason, the same effects as in the above examples can be obtained with respect to matching of characteristic impedance.

  The example of FIG. 3B can be implemented even when the signal pad 4a needs to be disposed on the outermost periphery of the array due to, for example, the design of the electronic component 21 or the external electric circuit.

  4A and 4B are plan views showing other variations of the wiring board and the electronic device shown in FIG. 2, respectively. 4, parts similar to those in FIG. 2 are denoted by the same reference numerals.

  In the example of FIG. 4A, among the signal pads 4 a, those located on the outermost periphery of the vertical and horizontal arrangement of the connection pads 4 are shifted to the center side of the lower surface of the insulating substrate 1. That is, the signal pad 4a is shifted in the direction in which the thermal stress in the connection between the connection pad 4 and the external electric circuit is reduced. Therefore, it is possible to provide the wiring substrate 10 and the electronic device 20 that are more effective in improving the reliability of external connection as the wiring substrate 10 and the electronic device 20.

  In this example, in addition to the outermost signal pad 4a, the signal pad 4a immediately inside the signal pad 4a is also shifted to the center of the lower surface of the insulating substrate 1. In this case, thermal stress is also reduced for the inner signal pad 4a, and the reliability of external connection as the wiring board 10 and the electronic device 20 is improved. Moreover, it is suppressed that the adjacent space | interval between the mutually adjacent signal pads 4a becomes too small, and electromagnetic interference of both is also suppressed.

  In the example of FIG. 4B, the connection conductor 8 is arranged between the signal pads 4a arranged adjacent to each other in the vertical or horizontal direction. The connection conductor 8 electrically connects the signal pad conductors 2a including the signal pads 4a. The connection conductor 8 is provided, for example, on the first main surface of the insulating substrate 1 and is covered with the coating layer 3. In this example, the connection conductor 8 passes through an intermediate portion between the signal pad conductors 2a adjacent to each other in order to ensure electrical insulation with the signal pad conductor 2a. The connection conductor 8 becomes a ground potential when the electronic device is operated (when energized), for example.

  When such a connection conductor 8 is arranged, electromagnetic interference between adjacent connection pad conductors 2a (connection pads 4a) is more effectively reduced by the connection conductor 8 having the ground potential. Can be done.

  The wiring board and electronic device of the present invention are not limited to the above-described embodiments, and various modifications are possible within the scope of the gist of the present invention. For example, the pad conductors 2 and the connection pads 4 are arranged substantially vertically and horizontally in each of the above examples, but may be arranged linearly (in one direction, vertically or horizontally). Further, it is not necessary to make all the size of the signal pad conductor 2a smaller than that of the ground pad conductor, and even when applied to only the signal pad conductor 2a in which high-frequency signals propagate and characteristic impedance matching is difficult. I do not care.

DESCRIPTION OF SYMBOLS 1 ... Insulating substrate 2 ... Pad conductor 2a ... Signal pad conductor 2b ... Ground pad conductor 3 ... Covering layer 4 ... Connection pad 4a ... Signal pad 4b ... -Grounding pad 5 ... Wiring conductor 6 ... Grounding conductor layer 7 ... Conductive connecting material 8 ... Connecting conductor
10 ... wiring board
20 ... Electronic device

Claims (5)

An insulating substrate having a first main surface;
A plurality of pad conductors arranged on the first main surface of the insulating substrate and including at least one signal pad conductor and at least one ground pad conductor adjacent to the signal pad conductor;
A coating layer covering from the first main surface of the insulating substrate to the outer periphery of each of the plurality of pad conductors,
A plurality of connection pads including at least one signal pad and at least one ground pad adjacent to the signal pad by an exposed portion inside the outer peripheral portion covered with the coating layer among the plurality of pad conductors. Is formed,
A wiring board, wherein the ground pad conductor is larger than the signal pad conductor in plan view, and the signal pad and the ground pad are the same size. The plurality of pad conductors are arranged vertically and horizontally,
The wiring board according to claim 1, wherein one signal pad conductor is surrounded by a plurality of ground pad conductors. 3. The wiring board according to claim 2, wherein in the plurality of ground pad conductors surrounding the signal pad conductors, adjacent intervals between the signal pad conductors and the ground pad conductors are the same. 4. The wiring board according to claim 1, wherein, in the plurality of pad conductors, the outer peripheral portion covered with the coating layer enters the inside of the insulating substrate. 5. The wiring board according to any one of claims 1 to 4,
An electronic device comprising: an electronic component mounted on a second main surface opposite to the first main surface of the insulating substrate.

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