JP6292908B2 - Printed circuit board - Google Patents

Description

  The present invention relates to a printed circuit board including a semiconductor device and a printed wiring board on which the semiconductor device is mounted.

  In recent years, along with an increase in current consumption of a semiconductor integrated circuit (Large-Scale Integration, hereinafter referred to as LSI) which is a semiconductor device, the amount of current flowing through a power supply conductor pattern and a power supply via conductor of a printed wiring board has also increased. It is known that when the current density flowing through the conductor increases, the possibility of the wiring being disconnected due to electromigration increases.

  The structure of the power line of the printed circuit board is as follows: surface power circuit → surface power conductor pattern → power via conductor → inner power conductor pattern ... It is common to wire a power supply line using

  Conventionally, when layers are switched by power supply via conductors, a large number of power supply via conductors are arranged in parallel in order to cope with a large current of LSI (see Patent Document 1). Patent Document 1 discloses a configuration in which a plurality of power supply via conductors are arranged in a square lattice pattern.

JP2013-229548A

  However, when a plurality of power supply via conductors are arranged in a square lattice pattern, there is a large variation in the distance between the power supply pads to which the terminals of the power supply unit are joined and the power supply via conductors. There could be large differences in quantity. Therefore, when a plurality of power supply via conductors are arranged in a square lattice shape, the current tends to concentrate on a specific power supply via conductor, so that the effect of distributing the current to each power supply via conductor is low.

  Therefore, an object of the present invention is to average the currents of a plurality of power supply via conductors.

The printed circuit board of the present invention includes a semiconductor device, a power supply unit that supplies power to the semiconductor device, and a printed wiring board on which the semiconductor device and the power supply unit are mounted. A first conductor layer and a second conductor layer laminated on the first conductor layer via an insulator layer, and the printed wiring board is disposed on the first conductor layer, and the power supply A power supply pad to which a terminal of a portion is bonded, a flat plate-like first power supply conductor pattern that is disposed on the first conductor layer and continues to the power supply pad, and is disposed on the second conductor layer, and the first power supply conductor When the pattern is projected onto the second conductor layer in the stacking direction, the second power supply conductor pattern overlapping the projection image of the first power supply conductor pattern, and the first power supply conductor pattern and the second power supply conductor pattern are electrically Multiple power supplies to connect to A power via conductor group composed of via conductors, and R is a median value of the distance between the center point of the power pad and the center point of each power via conductor of the power via conductor group. The center point of each power supply via conductor of the conductor group is included in a region surrounded by an arc having a radius of 0.6 × R and an arc having a radius of 1.4 × R centering on the center point of the power supply pad. A plurality of power supply via conductors of the power supply via conductor group are spaced apart from each other, and a plurality of the power supply via conductor groups are formed at intervals in the radial direction centered on the center point of the power supply pad. It is characterized by.

  According to the present invention, the currents of a plurality of power supply via conductors can be averaged.

It is explanatory drawing which shows schematic structure of the printed circuit board which concerns on 1st Embodiment. It is a partial top view of a printed wiring board when a printed wiring board is seen from the direction perpendicular | vertical to the surface layer of a printed wiring board. It is a schematic diagram of the power supply via conductor group for demonstrating arrangement | positioning of a power supply via conductor. It is a graph which shows a simulation result. It is a partial top view of a printed wiring board when a printed wiring board is seen from the direction perpendicular | vertical to the surface layer of the printed wiring board of the printed circuit board which concerns on 2nd Embodiment. It is explanatory drawing which shows the printed wiring board of a comparative example.

  Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings.

[First Embodiment]
FIG. 1 is an explanatory diagram showing a schematic configuration of a printed circuit board according to the first embodiment of the present invention. FIG. 1A is a cross-sectional view of a printed circuit board. FIG. 1B is a perspective view of the power supply line when only the power supply line is extracted from the printed wiring board.

  The printed circuit board 100 includes a printed wiring board 200, an LSI (semiconductor device) 301 and a power supply unit 302 mounted on the printed wiring board 200. The power supply unit 302 is an electric circuit that supplies power to the LSI 301.

  The LSI 301 is, for example, a BGA (Ball Grid Array) type or LGA (Land Grid Array) type semiconductor package, and has a plurality (or one) of power supply terminals 304 serving as DC voltage input terminals. In FIG. 1A, one power supply terminal 304 is shown.

  The power supply unit 302 includes a power supply circuit 311 and a power supply component 312. The power supply circuit 311 is a semiconductor element that adjusts an input AC or DC voltage to a DC voltage level necessary for driving the LSI 301 and outputs a DC voltage. The power supply component 312 is a passive element such as an inductor element, for example, and has a power supply terminal 303 serving as a DC voltage output terminal.

  In the first embodiment, the case where the power supply unit 302 includes two elements has been described. However, the power supply unit 302 may include one element, or may include three or more elements. . The power supply unit 302 may have a power source such as a battery. In any case, the power supply unit 302 has a power supply terminal 303 serving as a DC voltage output terminal.

  The printed wiring board 200 is a printed wiring board (motherboard) having two or more layers, for example, three conductor layers 201, 202, and 203. More specifically, the printed wiring board 200 includes a pair of surface layers 201 and 203 that are conductor layers, and an inner layer 202 that is a conductor layer disposed between the two surface layers 201 and 203. The printed wiring board 200 is laminated in the laminating direction (arrow Z direction) through the insulator layers 204 and 205 in this order: the surface layer 201 as the first conductor layer, the inner layer 202 as the second conductor layer, and the surface layer 203. It is configured.

  The LSI 301 and the power supply unit 302 are mounted on the surface layer (mounting surface) 201 of the printed wiring board 200.

  In the first embodiment, the power supply line 220 is disposed across the surface layer 201 and the inner layer 202 and electrically connects the power supply terminal (output terminal) 303 of the power supply unit 302 and the power supply terminal (input terminal) 304 of the LSI 301. Is formed. A ground line (not shown) is disposed across the surface layer 201 and the surface layer 203. On the surface layer 203, a solid conductor pattern (not shown) is formed on one surface.

  The power supply line 220 has a power supply pad (mounting pad) 221 formed on the surface layer 201 to which the power supply terminal 303 of the power supply unit 302 is joined by solder or the like. The power supply line 220 has a flat power supply conductor pattern 222 that is disposed on the surface layer 201 and is a first power supply conductor pattern formed continuously with the power supply pad 221. The power supply pad 221 and the power supply conductor pattern 222 are formed of one flat conductor. More specifically, the power supply pad 221 is a portion exposed in an opening formed in a solder resist (not shown) in the flat conductor, and the power supply conductor pattern 222 is a portion covered with the solder resist.

  The power supply line 220 has a flat power supply conductor pattern 224 that is a second power supply conductor pattern disposed on the inner layer 202. The power supply conductor pattern 224 is formed so as to overlap all (or a part) of the projected image when the power supply conductor pattern 222 is projected onto the inner layer 202 in the stacking direction (arrow Z direction).

  In the printed wiring board 200, through holes (or recessed holes) are formed in an overlapping portion between the power supply conductor pattern 222 and the power supply conductor pattern 224 and a portion corresponding to the power supply terminal 304 of the LSI 301. In these through holes (or recessed holes), power supply via conductor groups 223 and 225 that are part of the power supply line 220 are formed.

  That is, the power supply conductor pattern 222 and the power supply conductor pattern 224 are electrically connected by a power supply via conductor group 223 including a plurality (six in FIG. 1B) of power supply via conductors 231 extending in the stacking direction (arrow Z direction). It is connected. The plurality of power supply via conductors 231 are formed at intervals from each other in a direction orthogonal to the stacking direction.

  The power supply conductor pattern 224 and the power supply terminal 304 of the LSI 301 are electrically connected by a power supply via conductor group 225 including a plurality of power supply via conductors 241. These power supply via conductors 241 are also formed spaced apart from each other in a direction orthogonal to the stacking direction.

  Specifically, the LSI 301 has a plurality of (for example, two) power supply terminals 304, and a power supply via conductor 241 is formed corresponding to each power supply terminal 304 as shown in FIG. Yes. The via conductors 231 and 241 are formed in the through hole (recessed hole) so that the through hole (recessed hole) is hollow or solid.

FIG. 2 is a partial plan view of the printed wiring board 200 when the printed wiring board 200 is viewed from a direction perpendicular to the surface layer (mounting surface) 201 of the printed wiring board 200. In the first embodiment, the power supply via conductor group 223 includes six power supply via conductors 231, and in FIG. 2, the power supply via conductors 231 ₁ , 231 ₂ , 231 ₃ , 231 ₄ , 231 ₅ , and 231 ₆ are denoted. I will explain.

Here, the central point of the power supply pad 221 is P ₀ , and the central points of the power supply via conductors 231 ₁ , 231 ₂ , 231 ₃ , 231 ₄ , 231 ₅ , and 231 ₆ are P ₁ , P ₂ , P ₃ , P ₄ , P _5, and _{P 6.}

The median value of distances D _{1 to} D ₆ between the center point P ₀ of the power supply pad 221 and the center points P _{1 to} P ₆ of the power supply via conductors 231 _{1 to} 231 ₆ , in FIG. 2, the number of power supply via conductors is an even number. the average value of the two distances D ₅ and the distance D ₆ close to the center is the center value and the median value as R. When the number of power supply via conductors is an odd number, the center value is the distance of the power supply via conductors in the center. An arc having a radius R centered on the center point P ₀ of the power supply pad 221 is defined as C ₁ .

A plurality of power supply via conductors ₂₃₁ 1-231 _6, the center point _P 1 to P ₆ for each power via conductors ₂₃₁ 1-231 ₆ is included from the arc _{C 1} radially inwardly and a predetermined region of the outer a distance L As such, they are spaced apart from each other. This predetermined area is an area surrounded by an arc having a radius (R−L) and an arc having a radius (R + L) centered on the center point P ₀ . The distance L is preferably set so that the variation in the amount of current in the power supply via conductors 231 _{1 to} 231 ₆ falls within an allowable range, and specifically, set to 0.4 × R.

Accordingly, the distance _D 1 variation in to D ₆ is reduced, a current flows averaged for each power via conductors ₂₃₁ 1-231 _6. Therefore, current can be prevented from concentrating on a specific power via conductor, and disconnection of the power line 220 due to electromigration can be effectively prevented.

As shown in FIG. 2, the plurality of power via conductors 231 _{1 to} 231 ₆ are spaced from each other on one virtual arc centered on the center point P ₀ of the power pad 221, and on the arc C _{1 in} FIG. 2. It is arranged with a gap. Here, even if the center points P _{1 to} P ₆ deviate from the arc C ₁ , current can be effectively prevented from being concentrated on a specific power via conductor, but all the center points P ₁ to P on the arc C ₁ can be prevented. P ₆ can be prevented more effectively concentrate current if located.

FIG. 3 is a schematic diagram of a power supply via conductor group for explaining the arrangement of the power supply via conductors. In FIG. 3, for simplification of description, the case where the power supply via conductor group 223 includes three power supply via conductors 231 ₁ , 231 ₂ , and 231 ₃ is illustrated.

Power via conductors ₂₃₁ 1-231 _3, as the center point _P 1 to P ₃ of the power supply via conductors ₂₃₁ 1-231 ₃ is included in the predetermined region S of the distance L from the arc _{C 1} radially from each other They are arranged at intervals. The predetermined area S is equally divided by virtual straight lines L _A , L _B , L _C , and L _D centered on the center point P ₀ of the power supply pad 221 to be divided areas S ₁ , S ₂ , and S ₃ .

In Figure 3, it is formed by the power supply via conductors ₂₃₁ 1-231 ₃ predetermined region power via conductors ₂₃₁ 1 at both ends of the S which is placed, 231 central point _P 1 of _{3, P 3} and the center point _{P 0} of the power supply pads 221 the angle of the central angle of the arc C ₁ and θ that. Further, an angle (via arrangement angle) obtained by dividing the angle θ by the number of power supply via conductors (3 in FIG. 3) is defined as θ ′. The overlapping portions of the sector of the via arrangement angle θ ′ around the center point P ₀ of the power supply pad 221 and the predetermined region S are the divided regions S ₁ , S ₂ , S ₃ .

A plurality of power supply via conductors 231 _{1 to} 231 ₃ are arranged so that the center points of the power supply via conductors are included in each of the divided regions S ₁ , S ₂ , S ₃ one by one. At this time, as described above, the power supply via conductors 231 _{1 to} 231 ₃ are arranged at intervals.

As a result, the plurality of power supply via conductors 231 _{1 to} 231 ₃ are distributed and arranged in the circumferential direction along the arc C ₁ , so that a current is locally generated in the power supply conductor pattern 222 or the power supply conductor pattern 224. Concentration can be suppressed. Therefore, disconnection of the power supply line 220 due to electromigration can be more effectively prevented.

At this time, it is more preferable that the power supply via conductors 231 _{1 to} 231 ₃ are arranged at equiangular intervals around the center point P ₀ of the power supply pad 221. In this case, if the center point _P 1 to P ₃ of the power supply via conductors ₂₃₁ 1-231 ₃ on the arc _{C 1} is long located, the power supply via conductors ₂₃₁ 1-231 _3, the circumferential direction along a circular arc _{C 1} It will be arrange | positioned at equal intervals.

As described above, when the power supply via conductor 231 is arranged in an arc shape, there is no obstacle in the current path between the power supply via conductor and the power supply pad 221, and each power supply via conductor 231 ₁ from the center point P ₀ of the power supply pad 221. The distances to the center points P _{1 to} P _{6 of} ˜231 ₆ are substantially equal. Therefore, the current flowing from the power supply pads 221 may be would be substantially evenly distributed to each power via conductors ₂₃₁ 1-231 _6, to reduce the variation of the power supply via conductors ₂₃₁ 1-231 ₆ current.

  Note that the radius R and the angle θ may be appropriately determined depending on the number of power supply conductor patterns 222 and 224 and the number of power supply via conductors 231 according to the actual design.

  Here, the printed wiring board of a comparative example is demonstrated. FIG. 6A is a perspective view of the power supply line 220X when only the power supply line 220X is extracted from the printed wiring board of the comparative example. FIG. 6B is a partial plan view of the printed wiring board when the printed wiring board is viewed from a direction perpendicular to the surface layer 201 of the printed wiring board of the comparative example.

  The configuration of the power supply line 220X is the same as that of the power supply line 220 of the first embodiment except for the arrangement of the power supply via conductors.

In the comparative example, a plurality of power supply via conductors 231X _1, 231X ₂ are arranged in a square lattice, the power supply via conductors 223X ₁ with power via conductors 231X ₁ near side of the three to the power supply pads 221 are configured . The power supply via conductors 223X ₂ in three power via conductors 231X ₂ farther than the power supply pads 221 are configured to the power via conductors 223X _1.

For grid via arrangement of the comparative example, the amount of current of the power supply via conductors 231X ₁ power via conductors 223X ₁ power supply pad 221 side is larger than the power supply via conductors 231X ₂ power via conductor groups 223X _2. This can supply via conductors 223X ₁ is close to the power supply pad 221 than the power supply via conductors 223X _2, and the current path from the power supply pad 221 to the power supply via conductors 231X ₂ is narrowed by the power via conductors 231X _1, current This is because the ease of flow is reduced.

For the power supply line 220 of the first embodiment and the power supply line 220X of the comparative example, the variation in the current of the power supply via conductor was obtained by simulation. In the first embodiment, all power via conductors in the power via conductor group 223 are targeted as target via conductors for which current variation is obtained by simulation. In the comparative example, all power via conductors in the power via conductor groups 223X ₁ and 223X ₂ are targeted. Targeted.

  In the simulation, the parameters shown in Table 1 below were used for the printed wiring board of the first embodiment and the printed wiring board of the comparative example.

  Further, the simulator used PowerDC (Ver. 11.0.7.151151) of Sigrity, and the maximum and minimum differences of the currents of the respective via conductors obtained by simulation were defined as variations.

  Table 2 shown below is a simulation result.

  In the configuration of the first embodiment, it was confirmed that when the via current variation in the configuration of the comparative example was 1, the variation was reduced to about 0.19.

  Finally, the predetermined region S of the variation distance L will be described using the simulation result shown in FIG.

  As simulation models, four conditions were prepared in which only the arrangement of the power supply conductor pattern (surface power supply wiring) 222 and the power supply via conductor 231 in the surface layer of the model of the first embodiment was changed as shown in Table 3 below.

  Then, in the model under each condition, the distance between the center point of one power supply via conductor and the center point of the pad was changed in a direction approaching the power supply pad, and the dispersion of the via current was obtained by simulation.

  The horizontal axis of the graph shown in FIG. 4 is the ratio of the variation distance L to the radius R, and the vertical axis is the ratio of the current variation in the model of the first embodiment to the current variation of the via arrangement structure of the model of the comparative example. is there. Therefore, as the number on the horizontal axis increases, the variation distance increases, and the vertical axis indicates that when it is less than 1, there is a current variation reduction effect with respect to the comparative example.

  Here, each condition will be described. Condition 1, Condition 2, and Condition 3 are because the distance between the power supply via conductor and the power supply pad and the distance between the power supply via conductors are close to each other. The change in the current path is large. That is, this is a form in which a current change in the power supply via conductor is likely to occur.

  Under condition 4, the distance between the power supply via conductor and the power supply pad and the distance between the power supply via conductors are far away, so that the arrangement and shape of other adjacent power supply via conductors are changed, so that the power supply via conductors are originally separated from each other. In addition, the change in the current path to the power supply via conductor is small. That is, it is a form in which the current change of the power supply via conductor hardly occurs.

  From the above, in FIG. 4, when the ratio of the variation distance L to the radius R is smaller than 0.4, it is considered that the tendency of the current variation is different from the other conditions only in the condition 4. Also, it can be seen that, under any of the conditions, the ratio of the variation distance L to the radius R is 0.4 or less and the ratio of the current variation is less than 1 (a state in which a current variation reduction effect can be obtained).

  In particular, when considering an actual printed circuit board, considering that the conditions 1, 2, and 3 are close to the actual wiring shape and via arrangement interval, if the ratio of the variation distance L to the radius R is 0.4 or less, It is possible to obtain a large current variation reduction effect of about several tens of percent.

From the above, the variation distance L is
−0.4 × R ≦ L ≦ 0.4 × R (Formula 1)
It is desirable to satisfy the relationship.

That is, the maximum value of L is 0.4 × R, a predetermined area center point of the power supply via conductors 231 located S is the radius around the center point _{P 0 (R-0.4 × R} ) = 0 This is a region sandwiched between a 6 × R arc and a radius (R + 0.4 × R) = 1.4 × R arc.

[Second Embodiment]
Next, a printed circuit board according to a second embodiment of the present invention will be described. FIG. 5 is a partial plan view of a printed wiring board when the printed wiring board is viewed from a direction perpendicular to the surface layer of the printed wiring board of the printed circuit board according to the second embodiment of the present invention. In the first embodiment, the case where there is one power supply via conductor group has been described. In the second embodiment, a case where a plurality of power supply via conductor groups are formed will be described. Since the other configuration of the printed circuit board is the same as that of the first embodiment, description thereof is omitted. In the second embodiment, a printed wiring board in which another power supply via conductor group is newly added to the arrangement of the power supply via conductor group of the first embodiment will be described.

A plurality of power supply via conductor groups are formed on the surface layer 201 of the printed wiring board at intervals in the radial direction centered on the center point P ₀ of the power supply pad 221. A power supply via conductor group 223 described in the first embodiment and a power supply via conductor group 223A different from the power supply via conductor group 223 are formed on the surface layer 201 of the printed wiring board shown in FIG. The power supply via conductor group 223A is disposed behind the power supply via conductor group 223 close to the power supply pad 221 side (a position farther from the power supply pad 221 than the power supply via conductor group 223).

The power supply via conductor group 223A includes a plurality of power supply via conductors 231 ₇ , 231 ₈ , and 231 ₉ formed at intervals in a direction orthogonal to the stacking direction.

Thus, by arranging the plurality of power supply via conductors 223,223A, it is possible to reduce the current density at each power via conductors ₂₃₁ 1-231 ₆ power via conductors 223 is closest to the power supply pads 221. Therefore, disconnection due to electromigration can be effectively prevented.

Here, imaginary straight lines L _{1 to} L ₆ passing through the center points P _{1 to} P ₆ of the power supply via conductors 231 _{1 to} 231 ₆ of the power supply via conductor group 223 and the center point P ₀ of the power supply pad 221 are defined. The virtual straight line passing through the center point _{P 0} of the center point _P 7 to P ₉ and the power supply pads 221 of the power supply via conductors ₂₃₁ 7-231 ₉ arranged power via conductor group 223A behind the power via conductors 223 L _{7 to} L ₉ are defined.

  The other power supply via conductor group 223 is formed near the power supply pad 221 with respect to one power supply via conductor group 223A among the plurality of power supply via conductor groups 223 and 223A.

In the second embodiment, the virtual straight line _L 7 ~L ₉ is, so as not to contact the power supply via conductors ₂₃₁ 1-231 ₆ power via conductor groups 223, each power via conductors ₂₃₁ 1 power via conductors 223,223A 231 ₉ is arranged. This makes it easier for current to flow through the power supply via conductors 231 _{7 to} 231 ₉ of the power supply via conductor group 223A, and effectively prevents current from concentrating on the power supply via conductors 231 _{1 to} 231 ₆ of the power supply via conductor group 223. be able to.

  The present invention is not limited to the embodiment described above, and many modifications are possible within the technical idea of the present invention.

  In the first and second embodiments, the case where the printed wiring board is a mother board has been described. However, the present invention is not limited to this and may be an interposer in a semiconductor package. In this case, the semiconductor chip mounted on the interposer is a semiconductor device.

  In the second embodiment, the case where there are two power supply via conductor groups has been described. However, the present invention is not limited to this, and there may be three or more power supply via conductor groups.

  In the first and second embodiments, the case where the printed wiring board is composed of three conductor layers has been described. However, the present invention can be applied even when the printed wiring board is composed of two or four or more conductor layers. Is possible. At that time, another conductor layer may be interposed between the first conductor layer and the second conductor layer.

DESCRIPTION OF SYMBOLS 100 ... Printed circuit board, 200 ... Printed wiring board, 201 ... Surface layer (first conductor layer), 202 ... Inner layer (second conductor layer), 220 ... Power supply line, 221 ... Power supply pad, 222 ... Power supply conductor pattern (first Power supply conductor pattern), 223 ... Power supply via conductor group, 224 ... Power supply conductor pattern (second power supply conductor pattern), 302 ... Power supply unit, 303 ... Power supply terminal

Claims (6)

A semiconductor device;
A power supply unit for supplying power to the semiconductor device;
A printed wiring board on which the semiconductor device and the power supply unit are mounted;
The printed wiring board has a first conductor layer and a second conductor layer laminated on the first conductor layer via an insulator layer,
In the printed wiring board,
A power supply pad disposed on the first conductor layer to which a terminal of the power supply unit is joined;
A flat first power conductor pattern disposed on the first conductor layer and continuing to the power pad;
A second power supply conductor pattern disposed on the second conductor layer and overlapping a projection image of the first power supply conductor pattern when the first power supply conductor pattern is projected onto the second conductor layer in the stacking direction;
A power supply via conductor group including a plurality of power supply via conductors that electrically connect the first power supply conductor pattern and the second power supply conductor pattern; and
R is a median value of the distance between the center point of the power supply pad and the center point of each power supply via conductor of the power supply via conductor group;
The center point of each power supply via conductor of the power supply via conductor group is included in a region surrounded by an arc having a radius of 0.6 × R and an arc having a radius of 1.4 × R centering on the center point of the power supply pad. A plurality of power supply via conductors of the power supply via conductor group are spaced apart from each other ,
2. A printed circuit board according to claim 1, wherein a plurality of the power supply via conductor groups are formed at intervals in a radial direction centering on a center point of the power supply pad .   The plurality of power supply via conductors of the power supply via conductor group are arranged on one virtual arc centered on the center point of the power supply pad and spaced from each other. Printed circuit board.   The printed circuit board according to claim 2, wherein a center point of each power supply via conductor of the power supply via conductor group is on the virtual arc.   The plurality of power supply via conductors of the power supply via conductor group has a center point of the power supply via conductor in each divided region when the region is equally divided by a virtual straight line centered on the center point of the power supply pad. The printed circuit board according to claim 1, wherein the printed circuit board is disposed so as to be included.   5. The printed circuit according to claim 1, wherein a plurality of power supply via conductors of the power supply via conductor group are arranged at equiangular intervals around a center point of the power supply pad. 6. Board. An imaginary straight line passing through the center point of the power supply via conductor of one power supply via conductor group and the center point of the power supply pad among the plurality of power supply via conductor groups is located on the power supply pad rather than the one power supply via conductor group. so as not to contact the other of the power supply via conductors of the power supply via conductors close to either one of claims 1 to 5, characterized in that each of the power supply via conductors of the plurality of power supply via conductors are arranged The printed circuit board as described.

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