JP2015149336A - printed circuit board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To average currents of a plurality of power supply via conductors.SOLUTION: On a surface layer of a printed wiring board, a power supply conductor pattern 222 supplied with current from a power supply part is arranged. On an inner layer of the printed wiring board, a power supply conductor pattern 224 overlapped with a projection image of the power supply conductor pattern 222 when the power supply conductor pattern 222 is projected on the inner layer in a lamination direction, is arranged. The power supply conductor pattern 222 and the power supply conductor pattern 224 are electrically connected with each other via a plurality of power supply via conductors 231. In the power supply conductor pattern 224, openings H are provided at an interval to a power supply via conductor located at an end part in the width direction, at both sides of the plurality of power supply via conductors 231 in a width direction orthogonal to a direction of a current main path.

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, among the plurality of power supply via conductors, the current density flowing in the power supply via conductors arranged at the ends in the width direction orthogonal to the direction along the main current path is higher than the current density flowing in the other power supply via conductors. It tends to be high, and a large difference occurs in the amount of current. This difference in current amount is mainly caused by the width of the power supply conductor pattern into which current flows from each power supply via conductor. That is, since the power supply via conductors other than the end portions are surrounded by the other power supply via conductors, the current hardly flows as compared with the power supply via conductors at the end portions. On the other hand, the power via conductor at the end portion flows more easily than the power via conductors other than the end portion. As described above, when a plurality of power supply via conductors are arranged, 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 with an insulator layer interposed therebetween, and the printed wiring board is disposed on the first conductor layer, and the power A first power supply conductor pattern to which current is supplied from a supply unit and the first power supply conductor pattern disposed on the second conductor layer and projected onto the second conductor layer in the stacking direction. And a plurality of power supply via conductors that electrically connect the first power supply conductor pattern and the second power supply conductor pattern, and the plurality of power supply vias are formed. The conductor is the second Lined in a direction intersecting the direction of the current main path of the source conductor pattern, and openings are formed on both sides of the plurality of power supply via conductors arranged side by side in the second power supply conductor pattern. 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 fragmentary top view which shows a 2nd power supply conductor pattern. It is explanatory drawing which shows the power supply line in the printed wiring board of the printed circuit board which concerns on 2nd Embodiment. It is explanatory drawing which shows the power supply line in the printed wiring board of the printed circuit board which concerns on 3rd Embodiment. It is explanatory drawing which shows the power supply line in the printed wiring board of the printed circuit board which concerns on 4th Embodiment. It is explanatory drawing which shows the power supply line in the printed wiring board of the printed circuit board which concerns on 5th Embodiment. It is a fragmentary top view of the power supply conductor pattern of the power supply via conductor vicinity located in an edge part. It is explanatory drawing which shows the power supply line in the printed wiring board of the printed circuit board which concerns on 6th Embodiment. It is a graph which shows the relationship between the ratio of the slit distance with respect to an adjacent via pitch, and the variation ratio of a via current. It is a graph which shows the relationship between the width | variety of the electric current sub path | route with respect to an adjacent via pitch, and the dispersion | variation ratio of a via current. It is explanatory drawing which shows the power supply line in 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 via conductors 231 and 241 that are part of the power line 220 are formed.

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

  Further, the power supply conductor pattern 224 and the power supply terminal 304 of the LSI 301 are electrically connected by a plurality of power supply via conductors 241. Specifically, the LSI 301 has a plurality of (for example, two) power supply terminals 304. As shown in FIG. 1B, the power supply via conductor 241 extending in the stacking direction corresponding to each power supply terminal 304 is provided. Is formed. These power supply via conductors 241 are also formed at intervals from each other in a direction orthogonal to the stacking direction (arrow Z direction).

  The power supply via conductors 231 and 241 are formed in the through hole (or the recessed hole) so that the through hole (or the recessed hole) is hollow or solid.

  FIG. 2 is a partial plan view showing the power supply conductor pattern 224. 2A is a partial plan view of the power supply conductor pattern 224 in the vicinity of the plurality of power supply via conductors 231, and FIG. 2B is the vicinity of the power supply via conductor located at the end of the plurality of power supply via conductors 231. It is a fragmentary top view of the power supply conductor pattern 224 of.

As shown in FIG. 2A, the plurality of power supply via conductors 231 are arranged in a lattice shape in the width direction orthogonal to the direction X of the current main path R _O , in the direction X in which the current main path (region) R _O extends. Eight are arranged in Y. Here, it is most preferable that the direction X and the direction Y are perpendicular to each other. In FIG. 2 (a), eight power via conductors 231, it is sufficient arranged in a direction intersecting the direction X of the current main path R _O.

  In the first embodiment, the power supply conductor pattern 224 has openings (slits) on both sides in the width direction Y with respect to the plurality of power supply via conductors 231 (that is, on both sides of the group of power supply via conductors 231 arranged side by side in the direction Y). H is formed. The two openings H are openings formed in a quadrangle, and the openings H are filled with an insulator constituting the insulator layers 204 and 205 as a member having a higher electrical resistance than the power supply conductor pattern 224. Has been.

Opening H is formed in a plurality of power supply conductor pattern 224 at an interval in the width direction Y with respect to the power supply via conductors 231 ₁ positioned at the end portion in the width direction Y of the power supply via conductors 231.

If the absence opening H is, the power supply conductor pattern 224 from the power supply via conductors 231 _1, a current flows to diffuse to regions located opening H, current than the other power supply via conductors 231 ₂ Easy to flow structure.

On the other hand, in the first embodiment, the ease of current flow from the power supply via conductor 231 ₁ adjacent to the opening H to the power supply conductor pattern 224 is reduced, and the current flows to the power supply via conductor 231 ₂ other than the power supply via conductor 231 _1. The current is increased. Thus, current flows averaged for each power via conductors 231, it is possible to prevent the current in a particular power supply via conductors 231 ₁ concentrate. Therefore, the current density in the width direction Y can be made uniform in the power supply conductor pattern 224 (current main path R _O ). Thereby, disconnection of the power supply line 220 due to electromigration can be effectively prevented.

Also, for each power via conductors 231, since the opening H is not in the X (the traveling direction of the current) along the current main path R _O, to prevent the localized current density is increased in the power supply conductor pattern 224 Yes.

In addition, in 1st Embodiment, although the opening part H is a rectangle, it is not limited to a rectangle, Any shapes, such as a circle, may be sufficient. The length direction X of the current main path R _O of the opening portion H has a length approximately the same direction X of the arrangement region of the power supply via conductors 231 ₁ located at the end of the Y-direction of the plurality of power supply via conductors That is all you need. The power supply via conductors 231 and 231 the center point P between the pitch _{D P1} and the current main path _{R O} direction X of the power supply via conductors 231 and 231 the center point between P between P in the width direction Y, the pitch between the P the D _P2, may be the same, may be different from.

The distance (slit distance) D ₁ between the boundary (edge) B ₁ of the opening H and the center point P of the power supply via conductor 231 ₁ adjacent to the opening H is 0.0 ≦ D ₁ / D _P2 A range of ≦ 3.0 is preferred. If D ₁ / _{D P2} is greater than 3.0, the effect of the opening H is smaller. When the value of D ₁ is 0, the shape of the power supply via conductor 231 ₁ is a semicircle. The shape of the power supply via conductors 231 ₁ is smaller than a semicircle, since the function of the original via inductance of the power supply via conductors 231 itself is increased is reduced, not suitable. In the present embodiment, there are two power supply via conductors adjacent to the opening H. However, when there are two or more power via conductors, the distance between the center of the power supply via conductor 231 ₁ and the end B ₁ of the opening H the minimum value D ₁ of the smallest. Further, the minimum distance between the centers of the power supply via conductors 231 ₁ and 231 ₁ is set as a minimum value _DP2 .

By setting the distance D _{1 in} this manner, the amount of current flowing from the power supply via conductor 231 ₁ to the power supply conductor pattern 224 is adjusted, and the amount of current flowing through each power supply via conductor 231 can be more effectively equalized. . Therefore, the current density in the width direction Y can be made more uniform in the power supply conductor pattern 224. Therefore, disconnection due to electromigration in the power supply line 220 can be effectively prevented.

[Second Embodiment]
Next, a printed circuit board according to a second embodiment of the present invention will be described. FIG. 3 is an explanatory diagram showing power supply lines in the printed wiring board of the printed circuit board according to the second embodiment of the present invention. FIG. 3A is a perspective view showing a power supply line, and FIG. 3B is a partial plan view showing a second power supply conductor pattern of the power supply line. In the second embodiment, the configuration of the power supply line is partly different from the configuration of the power supply line in the first embodiment, and the same components are denoted by the same reference numerals and description thereof is omitted.

  The power supply line 220A of the printed wiring board in the second embodiment includes a power supply pad 221, a power supply conductor pattern 222, a plurality of power supply via conductors 231, and a plurality of power supply via conductors 241 as in the first embodiment. Furthermore, the power supply line 220A has a power supply conductor pattern 224A that is a second power supply conductor pattern having a shape different from that of the first embodiment.

The power supply conductor pattern 224 </ b> A is disposed on the opposite side of the current main path R _{O with} respect to the plurality of power via conductors 231 from the outer side in the width direction Y to the current main path R _O with respect to the opening H. A connecting current sub-path R is formed. Specifically, in FIG. 3B, a current sub-path (region) R is formed on the right side of the plurality of power supply via conductors 231. The current sub-path R is connected to the current main path R _O via the outside of the opening H in the width direction Y.

In the second embodiment, a plurality of power supply via conductors 231 includes a current main path R _O power supply via conductors 251 arranged in the width direction Y on the side of the opposite side to the side of the current main path R _O (current sub And a power supply via conductor group 252 arranged in the width direction Y on the path R side).

In the power supply conductor pattern 224A, in FIG. 3 (b), the current from the right side of the power via conductors 252, since the flow into the current main path R _O through the current pathway R, the power supply conductor pattern 224 of the first embodiment The current flows more easily than in the case. In particular, among the right side of the power via conductors 252, it flows easily power via conductors 231 ₁ except for the power supply via conductors 231 _{and second} current located at the end in the width direction Y. Therefore, the amount of current can be made uniform between the power supply via conductor group 251 and the power supply via conductor group 252. Further, the amount of current can be made uniform between the power supply via conductor groups 252.

  Further, since the opening H is formed in the power supply conductor pattern 224A as in the first embodiment, the opening H and the current sub-path R are combined, and further, than the first embodiment. The amount of current flowing through each power supply via conductor 231 can be more effectively equalized.

That is, the current by the sub route R was formed, power via conductors 252, in particular a power supply via conductors 231 ₂ via a current amount increase effect, increase the effect of suppressing power supply via conductors 231 ₁ via the current by opening H is at the same time Occur. Therefore, the amount of current flowing through each power supply via conductor 231 can be more effectively equalized than in the first embodiment. Therefore, it is possible to further uniform the current density in the width direction Y of the current flowing through the current main path R _O in the power supply conductor pattern 224A. Therefore, disconnection due to electromigration in the power supply line 220A can be effectively prevented.

The distance between the end side of the end side and the power supply conductor pattern 224A on the opposite side to the side of the current main path R _O of the openings H (width D ₂ of the region _R) is provided with openings H and the power supply conductor pattern 224A Determined by the boundary.

[Third Embodiment]
Next, a printed circuit board according to a third embodiment of the invention will be described. FIG. 4 is an explanatory diagram showing power supply lines in the printed wiring board of the printed circuit board according to the third embodiment of the present invention. 4A is a perspective view showing a power supply line, and FIG. 4B is a partial plan view showing a second power supply conductor pattern of the power supply line. In the third embodiment, the configuration of the power supply line is partly different from the configuration of the power supply line in the second embodiment, and the same components are denoted by the same reference numerals and description thereof is omitted. In the third embodiment, the arrangement of the power supply via conductors is changed with respect to the second embodiment.

  In the third embodiment, the power supply line 220B includes a plurality of power supply via conductors 231 having an arrangement different from that of the second embodiment, in addition to the power supply pad 221, the power supply conductor pattern 222, the power supply conductor pattern 224A, and the power supply via conductor 241.

A plurality of power supply via conductors 231, two or more of the directions X of the current main path R _O, composed of a plurality of power supply via conductors 260 formed by grouping one or more power via conductors in the width direction Y. In each power supply via conductor group 260, the number of power supply via conductors 231 in the width direction Y is preferably 1 or more and 2 or less. In the third embodiment, the power supply via conductors 260, two in the direction X of the current main path R _O, two in the width direction Y, is composed of a power supply via conductors 231 arranged in a total of four grid-like Yes.

Power via conductors distance between, specifically, the distance between the center points of the power supply via conductors 231 and 231 which face each other, of the pair of power supply via conductors 260 and 260 adjacent the (pitch) and D _G (FIG. 4 (b)). In the third embodiment, the distance D _G is widely set than the minimum pitch of the power supply via conductors of the respective power supply via conductors 260. (group) (the smaller pitch of the pitch D _P1 and pitch D _P2) ing.

According to the third embodiment, by increasing the spacing between adjacent power via conductors 260 and 260, the path of the than the second embodiment, the power supply via conductors 231 ₁ except for the power supply via conductors 231 ₂ via current Is secured. Thus, current flows easily in the respective power supply via conductors 231 _2.

Therefore, the amount of current flowing through each power supply via conductors 231 can be more effectively uniform and be more uniform current density in the width direction Y of the current flowing through the current main path R _O in the power supply conductor pattern 224A it can. Therefore, disconnection due to electromigration in the power supply line 220B can be effectively prevented.

[Fourth Embodiment]
Next, a printed circuit board according to a fourth embodiment of the invention will be described. FIG. 5 is an explanatory diagram showing power supply lines in the printed wiring board of the printed circuit board according to the fourth embodiment of the present invention. FIG. 5A is a perspective view showing a power supply line, and FIG. 5B is a partial plan view showing a second power supply conductor pattern of the power supply line. In the fourth embodiment, the group configuration of the power via conductor group is different from that of the third embodiment, and the same configurations as those of the first to third embodiments are denoted by the same reference numerals and described. Omitted.

  In the fourth embodiment, the power supply line 220C includes a plurality of power supply via conductors 231 having an arrangement different from that of the third embodiment, in addition to the power supply pad 221, the power supply conductor pattern 222, the power supply conductor pattern 224A, and the power supply via conductor 241.

A plurality of power supply via conductors 231, two or more of the directions X of the current main path R _O, composed of a plurality of power supply via conductors 260,260A formed by grouping one or more power via conductors in the width direction Y . In each power supply via conductor group 260, 260A, the number of power supply via conductors 231 in the width direction Y is preferably 1 or more and 2 or less.

In the fourth embodiment, each power via conductors 260, two in the direction X of the current main path R _O, two in the width direction Y, is composed of a power supply via conductors 231 arranged in a total of four grid-like Yes.

All the groups (power supply via conductor groups) may not have the same via configuration. In the fourth embodiment, the power supply via conductor group 260A is different from the power supply via conductor group 260 in the number of vias. Each power via conductors 260A in FIG. 5 (b), two in the direction X of the current main path R _O, 1 single in the width direction Y, is composed of a power supply via conductors 231 arranged in a total of two grid-like Yes.

Power via conductors 260A, the distance between 260A, power via conductors 260,260A distance between the power supply via conductors 260, 260 the distance between the _{D G.} In the fourth embodiment, the distance _{D G} is wider than the power supply via conductors within 260,260A (the smaller the pitch of the pitch _{D P1} and pitch _{D P2)} power via conductors a minimum pitch between the (group) Is set.

Therefore, in the fourth embodiment, the same as the third embodiment, the amount of current flowing through each power supply via conductors 231 can be more effectively uniform the current flowing through the current main path R _O in the power supply conductor pattern 224A The current density in the width direction Y can be made more uniform. Therefore, disconnection due to electromigration in the power supply line 220C can be effectively prevented.

[Fifth Embodiment]
Next, a printed circuit board according to a fifth embodiment of the invention will be described. FIG. 6 is an explanatory diagram showing power supply lines in the printed wiring board of the printed circuit board according to the fifth embodiment of the present invention. 6A is a perspective view showing a power supply line, and FIG. 6B is a partial plan view showing a second power supply conductor pattern of the power supply line. In the fifth embodiment, the shape of the opening in the third embodiment is changed. Since the configuration other than the opening is the same as that of the third embodiment, the same configuration is denoted by the same reference numeral and description thereof is omitted.

In the fifth embodiment, the power supply line 220D has a power supply conductor pattern 224D as the second power supply conductor pattern. The power supply conductor pattern 224D, are formed two openings (slits) H _D of different shapes from the opening H. Opening H _D, as well as the opening H, are formed on both sides in the width direction Y with respect to a plurality of power supply via conductors 231. In the fifth embodiment, the arrangement of the power supply via conductors 231 is the same as in the third embodiment, but may be the same as in the first, second, and fourth embodiments.

FIG. 7 is a partial plan view of the power supply conductor pattern in the vicinity of the power supply via conductor located at the end. In FIG. 7, among the power supply via conductor 231 ₁ located at the end, the power supply via conductor located on the side of the current main path R _O is opposite to the side of the power supply via conductor 231 _1-1 and the current main path R _O. The power supply via conductor located on the side is referred to as a power supply via conductor 231 _1-2 .

Opening _{H D} has a power supply via conductors _{231 1-1,} aperture _{H D1} is a first opening portion extending in the direction X of the current main path _{R O} as opposed to _{231 1-2.} The opening _{H D} has an opening part _{H D2} is a second opening portion that extends from the opening portion _{H D1} inward in the width direction Y so as to be opposed to the power supply via conductors _{231 1-2.}

Aperture _{H D1} is perpendicular to the power supply via conductors 231 _{1 -1,} 231 _1-2 current main path _{R O} opposed to the peripheral edge of the side aperture _{H D2,} the power supply via conductors 231 _1-2 Opposite to the current main path R _O. In other words, the opening portion H _D2 is formed wraps around the inside of the width direction Y be a current pathway R side to the power supply via conductors 231 _1-2. Thus, the power supply via conductors 231 _1-2 would behind the direction X in the width direction outside, and the current main path is surrounded by the opening H _D of the substantially L-shaped.

According to the fifth embodiment, the opening H _D, increasing the effect of suppressing the current of the power supply via conductors 231 _1-2, higher than arrangement of the first to fourth embodiments, other power via conductors 231 The effect of increasing the current increases. Further, since the arrangement of the power supply via conductors 231 are similar to the third embodiment increases the current increasing effect of the power supply via conductors 231 _2. Therefore, the current averaging effect is further enhanced in each power supply via conductor 231.

[Sixth Embodiment]
Next, a printed circuit board according to a sixth embodiment of the invention will be described. FIG. 8 is an explanatory diagram showing power supply lines in the printed wiring board of the printed circuit board according to the sixth embodiment of the present invention. FIG. 8A is a perspective view showing a power supply line, and FIG. 8B is a partial plan view showing a second power supply conductor pattern of the power supply line. Note that in the sixth embodiment, identical symbols are assigned to configurations similar to those in the first through fifth embodiments and descriptions thereof are omitted. Here, in the sixth embodiment, the shape of the opening H _D is the same as the fifth embodiment, the arrangement of the power supply via conductors 231 are similar to the first and second embodiments, a current pathway R Is the same as in the first embodiment.

  The shape of the opening may be the same as that in the first embodiment, or may be other shapes. Further, the power supply via conductors 231 may be arranged in the same manner as in the third and fourth embodiments.

In the sixth embodiment, the power supply line 220E has one end 271 to the current subpath R are electrically connected, the other end 272 to the current main path R _O has an electrically connected jumper wire 270. The jumper wire 270 is a flexible electric wire. The jumper wire 270 short-circuits the current sub-path R and the current main path R _O. According to the sixth embodiment, the current flowing through the current sub-path R can be increased, and the via current averaging effect utilizing current detouring can be further enhanced.

[Example]
Next, a simulation model is defined for the printed wiring board of the above embodiment, and a result of simulation performed on the simulation model will be described. In addition, FIG. 11 is explanatory drawing which shows the power supply line in the printed wiring board of a comparative example. 11A is a perspective view showing a power supply line, and FIG. 11B is a partial plan view showing a power supply conductor pattern of the power supply line. Similar to the first embodiment, the power line 1220 of the comparative example includes a power pad 221, a power conductor pattern 222, and power via conductors 231, 241 and no opening is formed in the power conductor pattern 224 of FIG. A power supply conductor pattern 1224 is provided. That is, the structure of the power supply line 1220 of the comparative example in FIG. 11 is the same as the structure without the opening H in the power supply line 220 of the first embodiment.

  The simulation was performed for the simulation model of the printed wiring board of the first, second, third, and fifth embodiments and the simulation model of the printed wiring board of the comparative example shown in FIG. In this simulation, the current density variation of the power supply via conductor (difference between the maximum and minimum values of the current generated in each power supply via conductor) was obtained.

  Table 1 below shows the substrate shape and electrical characteristics used in the simulation.

  In the simulation, PowerDC (Ver 11.0.7.151151) of Sigrity was used.

  Table 2 shows the simulation results, and represents the ratio of the current variation of each embodiment when the via current variation of the comparative example is 1. That is, the smaller the ratio, the higher the effect of reducing current variation. Therefore, it can be seen that the variation in the via current decreases as the models of the first, second, third, and fifth embodiments are obtained.

Next, the range of the distance between the opening and the adjacent power via conductor will be described with reference to FIG. FIG. 9 is a graph showing the relationship between the ratio of the slit distance to the adjacent via pitch and the variation ratio of the via current. FIG 9, under the condition of a fixed width _{D 2} of the current sub-path R to 1.8 [mm], 3, 4, in the arrangement of the three forms of power via conductors 231 in FIG. 5, the slit distance D The variation of the via current when ₁ is changed is shown.

  In addition, the simulation result based on the simulation model of the printed wiring board of FIG. 3 (2nd Embodiment) is a rhombus plot. The simulation result based on the simulation model of the printed wiring board in FIG. 4 (third embodiment) is a black circle plot. The simulation result based on the simulation model of the printed wiring board in FIG. 5 (fourth embodiment) is a white circle plot.

In the model of the fourth embodiment in FIG. 5, the distance _{DG is set} to 2.0 [mm], and the via pitches D _P1 and D _P2 are set to 1.0 [mm]. Other parameters are the same as those in the third embodiment (Table 1).

The horizontal axis of the graph shown in FIG. 9 is the ratio (D ₁ / D _P2 ) of the slit distance D ₁ to the pitch (adjacent via pitch) D _P2 of the power supply via conductors 231 ₁ , 231 ₁ adjacent to the opening H. The vertical axis represents the ratio of the current variation in the above three forms to the current variation of the comparative example (FIG. 11, structure shown in Table 1).

Therefore, when the number of the horizontal axis is increased, and the opening portion H, and the power supply via conductors 231 ₁ adjacent to the opening H indicates that the leaves, and the vertical axis, the current variation reduction effect for Comparative Example as smaller than 1 Is high.

As shown in FIG. 9, in any form, zero the ratio of the slit distance D ₁ relative to the adjacent via pitch D _P2, that is, as the opening and via distance D ₁ approaches zero, the higher variation reduction effect of the current I understand. Further, it can be seen that adjacent the via pitch D ratio of the slit distance D ₁ with respect to _P2 is current variation reduction effect by 3 or more is nearly saturated.

The simulation results, as the aperture H approaches the power supply via conductors 231 _1, the effect of limiting the flowability of the current in the power supply via conductors 231 _1, which indicates that also occur in which the via arrangement.

Conversely, the opening H is separated from the power supply via conductors 231 _1, in any via arrangement, the effect of limiting the flowability of the power supply via conductors 231 ₁ of the current is hardly obtained. This wiring region between the power supply via conductors 231 ₁ and the opening portion H ends up functioning as a current path, due to the fact that closer to the free state opening H.

From the above, the range of the distance D ₁ between the opening H and the power supply via conductor 231 ₁ is preferably the range of the following formula 1.
0.0 ≦ D ₁ / D _P2 ≦ 3.0 (Formula 1)

Next, the range of the width D ₂ of the current sub-path R, will be described with reference to FIG. 10.

  FIG. 10 is a graph showing the relationship between the width of the current sub-path with respect to the adjacent via pitch and the variation ratio of the via current. FIG. 10A shows a simulation result for the simulation model of the printed wiring board shown in FIG. 3 (second embodiment), and FIG. 10B shows the simulation model of the printed wiring board shown in FIG. 6 (fifth embodiment). The simulation result is shown.

In FIG. 10, the horizontal axis represents the ratio (D ₂ / D _P2 ) of the width D ₂ of the current sub-path R to the adjacent via pitch D _P2 , and the vertical axis represents the comparative example (the structure shown in FIG. 11 and Table 1). ) Current variation in the above two forms.

As shown in FIGS. 10 (a) and 10 (b), in any form, the current variation when the ratio (D ₂ / D _P2 ) of the width D ₂ of the current sub-path R to the adjacent via pitch D _P2 is 1 or more. It can be seen that the reduction effect approaches saturation.

Further, when the ratio (D ₂ / D _P2 ) of the width D ₂ of the current sub-path R to the adjacent via pitch D _P2 is 3 or more, the current variation reducing effect is almost saturated. Thus, current is also further increase the ratio of the width D ₂ (D 2 _{/ D P2)} of the sub path R, it can be seen that current variation reduction effect in accordance with the width D ₂ of the current sub-path R becomes difficult to obtain.

From the above, the range of Equation 2 is desirable as a range in which the effect of reducing current variation can be sufficiently obtained.
1.5 ≦ D ₂ / D _P2 ≦ 6.0 (Formula 2)

  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 to fifth 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.

  Moreover, although the said 1st-5th embodiment demonstrated the case where a printed wiring board consisted of 3 layers of conductor layers, this invention is applied even when it consists of 2 layers or a conductor layer of 4 layers or more. Is possible. At that time, another conductor layer may be interposed between the first conductor layer and the second conductor layer. Moreover, although the case where the first conductor layer is a surface layer and the second conductor layer is an inner layer has been described, the first conductor layer may be an inner layer, and the second conductor layer may be a surface layer.

DESCRIPTION OF SYMBOLS 100 ... Printed circuit board, 200 ... Printed wiring board, 201 ... Surface layer (first conductor layer), 202 ... Inner layer (second conductor layer), 204, 205 ... Insulator layer, 220 ... Power supply line, 222 ... Power supply conductor pattern (First power supply conductor pattern), 224 ... power supply conductor pattern (second power supply conductor pattern), 231 ... power supply via conductor, 302 ... power supply section, H ... opening, R _O ... current main path

Claims (9)

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 first power supply conductor pattern disposed on the first conductor layer and supplied with current from the power supply unit;
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 plurality of power supply via conductors that electrically connect the first power supply conductor pattern and the second power supply conductor pattern;
The plurality of power supply via conductors are arranged in a direction intersecting a direction of a current main path of the second power supply conductor pattern,
An opening is formed on both sides of the plurality of power supply via conductors arranged side by side in the second power supply conductor pattern. The relationship between the minimum value D ₁ of the distance between the center of the power supply via conductor and the end of the opening and the minimum value D _{P2 of the} distance between the centers of the power supply via conductors is 0.0 ≦ D ₁ / D _P2 The printed circuit board according to claim 1, wherein ≦ 3.0.   The printed circuit board according to claim 1, wherein the opening is filled with a member having a resistance higher than that of the second power supply conductor pattern.   The printed circuit board according to claim 3, wherein the high-resistance member is an insulator.   The second power supply conductor pattern is disposed on the opposite side of the plurality of power supply via conductors from the current main path side. The current main path of the second power supply conductor pattern with respect to the opening. 5. The printed circuit board according to claim 1, wherein a current sub-path that is connected to the current main path from the outside in a direction that intersects the direction of is formed.   6. The printed circuit board according to claim 5, further comprising a jumper wire having one end electrically connected to the current sub-path and the other end electrically connected to the current main path.   The plurality of power via conductors are grouped by two or more power via conductors in the direction of the current main path and one or more power via conductors in a direction crossing the direction of the current main path of the second power conductor pattern. The printed circuit board according to any one of claims 1 to 6, wherein the printed circuit board includes power via conductor groups, and a distance between the power via conductor groups is wider than a minimum pitch between the power via conductors. .   8. The printed circuit board according to claim 7, wherein each power supply via conductor group includes two power supply via conductors in a direction intersecting a direction of a main current path of the second power supply conductor pattern. 9.   The opening includes a first opening portion extending in the direction of the current main path so as to face the power supply via conductor located at an end in a direction intersecting the direction of the current main path of the second power supply conductor pattern; The first opening portion so as to face the power supply via conductor located on the side opposite to the current main path side of the power supply via conductor located at the end of the two power supply conductor pattern in the direction intersecting the direction of the current main path. 9. The printed circuit board according to claim 1, further comprising: a second opening portion extending inward in the width direction from the first to eighth portions.

Images