JP2002057462A - Multilayered printed circuit board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem that conventionally a crosswalk noise is generated between adjacent signal wirings when a wiring interval is narrowed in a multilayered circuit board, having a parallel wiring a group. SOLUTION: In the multilayered printed circuit board, a second insulating layer I2, having a second parallel wiring group L2 perpendicular to a first parallel wiring group L1, is laminated on a first insulating layer I1 having the first group L1. The first and second groups L1 and L2 are connected via a feedthrough conductor group T. The groups L1 and L2 respectively have a plurality of signal wirings S1 and S2 and power wirings P1 and P2 adjacent to the wirings S1 and S2 or ground wirings G1 and G2. The thickness of the wiring conductor of each of the wirings P1 and P2, adjacent to the wirings S1 and S2 or the wirings G1 and G2, is set larger than that of each of the wirings S1 and S2. Crosswalks between the wirings S1 and between the wirings S2 can be reduced effectively.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multilayer wiring board used for an electronic circuit board or the like, and more particularly to a wiring structure in a multilayer wiring board on which a semiconductor element operating at a high speed is mounted.

[0002]

2. Description of the Related Art Conventionally, in a multilayer wiring board on which a semiconductor element such as a semiconductor integrated circuit element is mounted and which is used for an electronic circuit board or the like, an insulating material made of ceramics such as alumina is used for forming a wiring conductor for internal wiring. Layers and wiring conductors made of a refractory metal such as tungsten (W) are alternately stacked to form a multilayer wiring board.

In a conventional multilayer wiring board, signal wirings of internal wiring wiring conductors usually have a strip line structure, and a so-called solid pattern is formed above and below wiring conductors formed as signal wirings via insulating layers. A ground (ground) layer or a power supply layer having a wide area of the shape was formed.

Further, with the increase in the speed of electric signals handled by the multilayer wiring board, the insulating layer is replaced with alumina ceramics having a relative dielectric constant of about 10, and a polyimide resin or epoxy resin having a relatively small relative dielectric constant of 3.5 to 5 is used. And a conductive layer for internal wiring made of copper (Cu) is formed on the insulating layer by using a thin film forming technique such as a vapor deposition method such as a vapor deposition method or a sputtering method. By forming a wiring conductor in a pattern and multiplying the insulating layer and the wiring conductor into layers, a multilayer wiring board having a high density, a high function and a high speed operation of a semiconductor element has been obtained.

On the other hand, the wiring structure of the internal wiring of the multilayer wiring board is designed to reduce the impedance of the wiring, reduce the crosstalk between signal wirings, etc. A structure has been proposed in which a group of parallel wirings is formed, which is multi-layered, and predetermined wirings in the wiring group of each layer are electrically connected to each other via through conductors such as via conductors and through-hole conductors.

In a multilayer wiring board having such parallel wiring groups, an electronic component such as a semiconductor element mounted on the multilayer wiring board is electrically connected to a mounting board on which the multilayer wiring board is mounted. Then, an appropriate wiring is selected from each parallel wiring group in the multilayer wiring board, and the connection between the wirings between different wiring layers is performed via a through conductor such as a via conductor.

[0007]

However, in the conventional multilayer wiring board, the spacing between the wirings is set to be narrow by increasing the density of the parallel wiring group constituting each wiring layer, and the so-called narrow pitch of the wirings is performed. In this case, the distance between the signal wirings is also narrowed, and the signal wirings for transmitting different high-frequency signals are close to each other, so that the electromagnetic coupling force between these signal wirings is strengthened. There is a problem that crosstalk occurs between wirings and crosstalk noise increases.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide a laminated wiring body composed of a group of parallel wirings which are alternately arranged in a stack and electrically connected by a group of through conductors. In the multi-layer wiring board provided, even when the wiring interval of the parallel wiring group is narrowed to increase the density, the crosstalk between the signal wirings can be reduced and the generation of crosstalk noise can be suppressed. An object of the present invention is to provide a multilayer wiring board suitable for an electronic circuit board or a package on which a semiconductor element such as a semiconductor integrated circuit element operating at a high speed is mounted.

[0009]

According to the present invention, there is provided a multilayer wiring board comprising a second parallel wiring group orthogonal to the first parallel wiring group on a first insulating layer having the first parallel wiring group. A first insulating layer having a first insulating layer, a first insulating layer, a first insulating layer, and a second insulating layer. Each of the groups has a plurality of signal wirings, a power supply wiring or a ground wiring adjacent to each signal wiring, and a wiring conductor of the power supply wiring or the ground wiring adjacent to these signal wirings is thicker than the signal wiring. It is a feature.

According to the multilayer wiring board of the present invention, the first and second parallel wiring groups each have a plurality of signal wirings, a power supply wiring or a ground wiring adjacent to each signal wiring, and the signal wirings Since the thickness of the wiring conductor of the adjacent power supply wiring or ground wiring is made thicker than that of the signal wiring, the thicker power supply wiring or ground wiring located between the signal wirings reduces the electromagnetic coupling force between the signal wirings. Since it is weakened, it is possible to reduce crosstalk between signal wirings in the parallel wiring group and suppress occurrence of crosstalk noise.

Thus, according to the multilayer wiring board of the present invention, there is provided a multilayer wiring board having a multilayer wiring body composed of a group of parallel wirings alternately arranged orthogonally and stacked and electrically connected by a group of through conductors. A high-speed semiconductor integrated circuit that can reduce the crosstalk between signal wirings and suppress the occurrence of crosstalk noise even when the density of the parallel wiring groups is reduced by reducing the wiring interval. A multilayer wiring board suitable for an electronic circuit board, a package, or the like on which a semiconductor element such as an element is mounted.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a multilayer wiring board according to the present invention will be described in detail based on an embodiment shown in the accompanying drawings.

FIG. 1 shows an example of an embodiment of a laminated wiring body according to the multilayer wiring board of the present invention.
3B is a plan view of a main part of the first insulating layer, and FIG. 3B is a plan view of a main part of the second insulating layer. FIG. 2 is a plan view of an essential part showing an example of an embodiment of a multilayer wiring board of the present invention including a laminated wiring body obtained by laminating them. Further, FIG.
FIG. 3 is a sectional view taken along line AA ′ of the multilayer wiring board shown in FIG.

In these figures, I1 to I3 are first to third insulating layers, respectively, and L1 and L2 are disposed substantially parallel to the upper surfaces of the first and second insulating layers I1 and I2, respectively. These are the first and second parallel wiring groups. The second parallel wiring group L2 is arranged such that each wiring conductor is orthogonal to the first parallel wiring group L1.

P1 and P2 are power supply wirings in the first and second parallel wiring groups L1 and L2, respectively, G1 and G2 are ground wirings in the first and second parallel wiring groups L1 and L2, respectively.
S2 indicates a signal wiring in the first and second parallel wiring groups L1 and L2, respectively.

T is a through conductor group for electrically connecting the first parallel wiring group L1 and the second parallel wiring group L2 at a predetermined location.

As described above, in the laminated wiring body of the multilayer wiring board of the present invention, the first parallel wiring group L1 including the signal wiring S1 and the power supply wiring P1 or the ground wiring G1 adjacent thereto is substantially in the first direction. A second parallel wiring group L2 including a signal wiring S2 and a power supply wiring P2 or a ground wiring G2 adjacent to the signal wiring S2 stacked in parallel and stacked thereon.
Are disposed substantially parallel to a second direction orthogonal to the first direction, and these wirings are electrically connected to each other by a through conductor group T penetrating through the second insulating layer I2 to form a laminate. It constitutes a wiring body.

According to such a stacked wiring body, since the first parallel wiring group L1 and the second parallel wiring group L2 are stacked so as to be orthogonal to each other, the parallel wiring groups L1 and L
Crosstalk noise between the two wirings can be reduced to a minimum.

The plurality of signal lines S1 and S2 arranged on the same plane may transmit different signals, respectively, and the plurality of power lines P1 and S1 arranged on the same plane may be used.
P2 may supply different powers.

I3 is laminated on the second insulating layer I2,
This is a third insulating layer to be a surface layer of the multilayer wiring board. The third insulating layer I3 is formed as needed. For example, when the second parallel wiring group L2 is provided in the second insulating layer I2, the third insulating layer I3 is not necessarily formed. .

In such a multilayer wiring board, for example, an MPU (Micro Processing Unit) / ASIC (A
pplication Specific Integrated Circuit) ・ DSP
A semiconductor device such as a semiconductor integrated circuit device such as a digital signal processor (Digital Signal Processor) is mounted. Then, it is used as a package for storing semiconductor elements, a substrate for mounting semiconductor elements, a so-called multi-chip module or multi-chip package on which a large number of semiconductor integrated circuit elements are mounted, a motherboard, or the like. These semiconductor elements are mounted on the surface of the multilayer wiring board by, for example, so-called bump electrodes, or are attached to a mounting portion by an adhesive, a brazing material, or the like, and are connected to the mounting portion via a bonding wire, for example, by a through conductor. It is electrically connected to the second parallel wiring group L2. A connection portion with an external electric circuit and a connection portion with a mounted semiconductor element are not shown.

The through conductor group T penetrates through the second insulating layer I2 to electrically connect the upper and lower wirings. Usually, a through-hole conductor, a via conductor, or the like is used, and the necessary conductors for the connection are used. Formed at the location. A similar through conductor group is also used to electrically connect the wiring of each of the parallel wiring groups L1 and L2 to an electronic component or an external connection terminal attached to the surface of the multilayer wiring board.

In the multilayer wiring board according to the present invention, as shown in FIGS. 1 to 3, the first and second parallel wiring groups L1 and L2 each include a plurality of signal wirings S1 and S2.
And power supply lines P1 and P adjacent to the signal lines S1 and S2.
2 and the ground wirings G1 and G2, and the thickness of the wiring conductors of the power wirings P1 and P2 or the ground wirings G1 and G2 adjacent to the signal wirings S1 and S2 is set to the signal wiring S.
The thickness is larger than the thickness of the wiring conductor of 1.S2. As a result, the electromagnetic coupling force between the signal lines S1 and S2 adjacent to each other in the same parallel wiring group L1 and L2 becomes
Since the power lines P1 and P2 or the ground lines G1 and G2 formed by thick wiring conductors located therebetween are weakened, crosstalk between the signal lines S1 and S2 is reduced to reduce the signal lines S1 and S2. The generated crosstalk noise can be greatly reduced.

In the multilayer wiring board of the present invention, when the power supply wirings P1 and P2 or the grounding wirings G1 and G2 having the thicker wiring conductors are provided, the power supply wiring P1.
In order to reduce the crosstalk efficiently, the thickness of the wiring conductor of the P2 or the ground wirings G1 and G2 is set such that the width, the distance between the signal wirings S1 and S2, the length with respect to the signal wirings S1 and S2, and the like are parallel. A desired characteristic impedance is obtained for the signal lines S1 and S2 in consideration of the electrical characteristics based on the size, shape, and material of each part of the wiring groups L1 and L2 and each through conductor T, the electromagnetic characteristics for high frequencies, and the like. It may be set appropriately in consideration of the situation.

The thickness of the wiring conductors of the power supply wirings P1 and P2 or the grounding wirings G1 and G2 is determined by the thickness of the signal wiring S1.
From the viewpoint of most effectively reducing the crosstalk between S1 and S2, the first and second parallel wiring groups L1 and L2
In the above, it is preferable that the thickness be about 1.2 to about 2 times the thickness of the wiring conductor of the adjacent signal wiring S1 or S2 to be targeted. If the thickness is less than about 1.2 times, the electromagnetic coupling between the signal wirings S1 and S2 is hardly weakened, so that crosstalk cannot be sufficiently reduced, and the magnitude of crosstalk noise is less than about 5%. Tends to be reduced only to an insufficient degree. On the other hand, when the thickness is much more than about twice the thickness of the signal wirings S1 and S2, the first and second stacked layers sandwiching the first and second parallel wiring groups L1 and L2 when forming the multilayer wiring board. There is a tendency that the adhesion between the insulating layers I1 and I2 becomes insufficient and the production of the multilayer wiring board becomes difficult.

In the multilayer wiring board of the present invention, for example,
For example, the relative dielectric constant ε _rBut about 10 same invitations
The thickness of the insulating layer is 254 μm using
Wiring width is 100 μm, signal wiring thickness is 14 μm,
Between a wire and its adjacent power or ground wire
The stacked wiring body shown in FIGS.
In this case, the power supply wiring P adjacent to each of the signal wirings S1 and S2
The thickness of the wiring conductor of 1 · P2 or the ground wiring G1 · G2 is
When the thickness of the signal conductors S1 and S2 is the same,
The crosstalk noise of the signal lines S1 and S2 is 7.79 mV.
Become. On the other hand, adjacent to each of the signal lines S1 and S2
Wiring of power supply lines P1 and P2 or ground lines G1 and G2
The thickness of the body is twice the thickness of the wiring conductors of the signal wiring S1 and S2
, The crosstalk noise of the signal lines S1 and S2
Noise can be reduced to 6.4 mV.

In the above configuration, similar parallel wiring groups are orthogonally arranged below the first parallel wiring group L1 and above the second parallel wiring group L2 in the example shown in FIGS. The present invention can also be applied to a case where they are stacked and arranged and are electrically connected to them by a through conductor group.

Further, with respect to the multilayer wiring board of the present invention,
On and under the first and second parallel wiring groups L1 and L2, multilayer wiring portions having various wiring structures can be stacked to form a multilayer wiring board. For example, a wiring structure having a structure in which parallel wiring groups are orthogonally stacked like a multilayer wiring body, a wiring structure having a strip line structure, and other specifications required for a multi-layer wiring substrate such as a microstrip line structure and a coplanar line structure. It can be appropriately selected and used according to the conditions.

Further, the first and second parallel wiring groups L1
A ground conductor layer having a function as an electromagnetic shield for EMI noise or the like may be provided above and below L2.

Further, for example, an electronic circuit may be formed by laminating a polyimide insulating layer and a conductor layer formed by copper vapor deposition, such as a chip resistor, a thin film resistor, a coil inductor, a cross capacitor, a chip capacitor, and an electrolytic capacitor. It may be attached to form a semiconductor element storage package.

The shape of each insulating layer including the first to third insulating layers I1 to I3 is not limited to a substantially square shape as shown in a plan view of a main part, but is a rectangular shape. Or a shape such as a rhombus or a polygon.

Note that the first and second parallel wiring groups L1.
L2 is not limited to those formed on the surfaces of the first and second insulating layers I1 and I2, and may be formed inside the respective insulating layers I1 and I2.

Further, as compared with the example shown in FIG. 3 or FIG. 6, the third insulating layer I3 is not laminated and the second parallel wiring group L
2 may be formed on the surface of the second insulating layer I2 to be exposed on the surface of the multilayer wiring board.

In the multilayer wiring board of the present invention, each of the first to third insulating layers I1 to I3 is formed of an aluminum oxide sintered body or an aluminum nitride sintered body by, for example, a ceramic green sheet laminating method. Silicon carbide sintered body
Using inorganic insulating materials such as silicon nitride sintered body, mullite sintered body, glass ceramics, or organic insulating materials such as polyimide, epoxy resin, fluororesin, polynorbornene, benzocyclobutene, Alternatively, it is formed using an electrical insulating material such as a composite insulating material formed by bonding an inorganic insulating powder such as a ceramic powder with a thermosetting resin such as an epoxy resin.

When these insulating layers are made of, for example, an aluminum oxide sintered body, a suitable organic binder, a solvent, etc. are added to a raw material powder of aluminum oxide, silicon oxide, calcium oxide, magnesium oxide or the like and mixed. A ceramic green sheet was obtained by forming the sheet into a sheet shape by employing a well-known doctor blade method, and thereafter, the ceramic green sheet was subjected to an appropriate punching process and each parallel wiring was formed. The group and each through conductor group and the metal paste to be the conductor layer are printed and applied in a predetermined pattern and laminated vertically,
Finally, the laminate is manufactured by firing at a temperature of about 1600 ° C. in a reducing atmosphere.

The thickness of these insulating layers is determined in accordance with the characteristics of the material to be used, so as to satisfy the conditions such as mechanical strength and electrical characteristics corresponding to the required specifications and the ease of forming the through conductor group. It is set appropriately.

The first and second parallel wiring groups L1.
L2 and other wiring layers, ground conductor layers GL, through conductor groups, and the like are made of metal powder metallized, for example, tungsten, molybdenum, molybdenum-manganese, copper, silver, silver-palladium, or copper, silver, nickel, chrome, titanium. -It is composed of a thin film of a metal material such as gold, niobium, or an alloy thereof.

For example, in the case of metallization of metal powder of tungsten, a metal paste obtained by adding and mixing an appropriate organic binder, solvent and the like to the tungsten powder is printed in a predetermined pattern on a ceramic green sheet serving as an insulating layer. By applying and firing this together with the ceramic green sheet laminate, it is disposed on the upper surface of each insulating layer.

In the case of a thin film of a metal material, a metal layer is formed by, for example, a sputtering method, a vacuum evaporation method, or a plating method, and then a predetermined wiring pattern is formed by a photolithography method.

The width and the interval between the wirings of the first and second parallel wiring groups L1 and L2, or the through conductor group T
The shape, dimensions, arrangement position, etc. of the insulation layer I and the electrical characteristics corresponding to the required specifications depend on the characteristics of the material used.
It is set appropriately so as to satisfy conditions such as ease of disposition in 1.I2.

The thickness of each of the parallel wiring groups L1 and L2 is 1
It is preferably about 20 μm. This thickness is 1 μm
When the value is less than the above, the resistance of the wiring increases, and it tends to be difficult to provide a good power supply to the semiconductor element by the wiring group, secure a stable ground, and propagate a good signal.
On the other hand, if it exceeds 20 μm, the insulation layer laminated thereon may be insufficiently covered, resulting in poor insulation.

Each of the through conductors in the through conductor group T may have a rectangular cross section other than a circular cross section, a rectangular shape such as an elliptical shape, a square or a rectangular shape, or any other shape. The position and size are appropriately set according to the characteristics of the material to be used so as to satisfy conditions such as electrical characteristics corresponding to required specifications and easiness of formation and arrangement on the insulating layer.

For example, when the aluminum oxide sintered body is used for the insulating layer and the metallization of tungsten is used for the parallel wiring group, the thickness of the insulating layer is set to 200 μm.
By setting the line width of the wiring to 100 μm, the spacing between the wirings to 150 μm, and the size of the through conductor to 100 μm, the impedance of the signal wiring is set to 50Ω, and the electrical connection between the upper and lower parallel wiring groups is suppressed while suppressing the reflection of high-frequency signals. Can be connected to

It should be noted that the present invention is not limited to the above-described embodiments, and that various changes may be made without departing from the spirit of the present invention. For example, in the above-described embodiment, the present invention has been described as a multilayer wiring board on which a semiconductor element is mounted. However, the present invention may be applied to a semiconductor element housing package for housing a semiconductor element or a multi-chip module. Further, an aluminum nitride-based sintered body / silicon carbide-based sintered body considering heat dissipation or a glass ceramics-based sintered body considering low dielectric constant may be used.

[0045]

According to the multilayer circuit board of the present invention, each of the first and second parallel wiring groups has a plurality of signal wirings and a power supply wiring or a ground wiring adjacent to each signal wiring. Since the thickness of the wiring conductor of the power supply wiring or the ground wiring adjacent to the wiring is thicker than that of the signal wiring, the electromagnetic coupling between the signal wirings is provided by the thick power supply wiring or the ground wiring located between the signal wirings. Since the force is weakened, it is possible to reduce the crosstalk between the signal wirings in the parallel wiring group and suppress the generation of crosstalk noise.

As described above, according to the multilayer wiring board of the present invention, there is provided a multilayer wiring board having a multilayer wiring body composed of a group of parallel wirings which are alternately arranged and stacked orthogonally and are electrically connected by a group of through conductors. A high-speed semiconductor integrated circuit that can reduce the crosstalk between signal wirings and suppress the occurrence of crosstalk noise even when the density of the parallel wiring groups is reduced by reducing the wiring interval. A multilayer wiring board suitable for an electronic circuit board, a package, or the like on which a semiconductor element such as an element is mounted.

[Brief description of the drawings]

FIGS. 1A and 1B show an example of an embodiment of a multilayer wiring body according to a multilayer wiring board of the present invention, wherein FIG. 1A shows a first insulating layer, and FIG. 1B shows a main part of a second insulating layer. FIG.

FIG. 2 is a main part plan view showing an example of an embodiment of a multilayer wiring board of the present invention.

FIG. 3 is a sectional view taken along line AA ′ of the multilayer wiring board shown in FIG. 2;

[Explanation of symbols]

 ... I1 to I3... Insulating layer L1, L2... Parallel wiring group P1, P2... Power supply wiring G1, G2... Ground wiring S1, S2. ..... Groups of through conductors

Claims (1)

[Claims] 1. A second insulating layer having a second parallel wiring group orthogonal to the first parallel wiring group is laminated on a first insulating layer having a first parallel wiring group. 1st and 2nd
And a plurality of signal wirings, and a power supply adjacent to each signal wiring. The first and second parallel wiring groups each include a plurality of signal wirings. A multilayer wiring board having a wiring or a ground wiring, wherein the thickness of a wiring conductor of a power supply wiring or a ground wiring adjacent to the signal wiring is larger than that of the signal wiring.