JP3878878B2 - Wiring board - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a wiring substrate used for a semiconductor element mounting substrate for mounting a semiconductor element such as a semiconductor integrated circuit element.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a wiring board used as a semiconductor element mounting substrate for mounting a semiconductor integrated circuit element has a plurality of insulating layers made of an inorganic insulator such as an aluminum oxide sintered body and an organic insulator such as an epoxy resin. A grounding conductor layer for supplying a ground potential to the semiconductor integrated circuit element and a power supply conductor layer for supplying a power supply potential to the semiconductor integrated circuit element between the insulating layers of the insulating base formed by integrating the layers vertically And a signal conductor layer for inputting / outputting signals to / from the semiconductor integrated circuit element, and the grounding conductor layer, the power source conductor layer, and the signal conductor layer on the upper and lower surfaces of the insulating substrate, respectively. A large number of substantially circular electrode pads that are electrically connected are formed. The grounding conductor layer, the power supply conductor layer, the signal conductor layer and the electrode pad pass through the insulating layer from the grounding conductor layer, the power supply conductor layer, and the signal conductor layer, respectively. Are electrically connected to each other by a large number of through conductors led out from the top to the bottom. The wiring board is mounted so that the semiconductor integrated circuit element is electrically connected to the upper surface of the insulating base, and the electrode is electrically connected to the electrode pad on the upper surface of the insulating base via a conductive bonding member such as a solder bump. At the same time, a sealing resin made of a thermosetting resin such as an epoxy resin is fixed on the upper surface of the insulating base so as to cover the semiconductor integrated circuit element, and the semiconductor device is a product of the insulating base. It is mounted on the external electric circuit board by connecting the electrode pads on the lower surface to the wiring conductor of the external electric circuit board via a conductive bonding member such as solder.
[0003]
By the way, in such a wiring board, with the recent high integration of semiconductor integrated circuit elements, a grounding conductor layer and a power supply conductor layer for supplying a ground potential and a power supply potential to the semiconductor integrated circuit element are: In many cases, each pattern is provided as a wide area pattern covering one or several of the entire insulating layers of the insulating base. By supplying a ground potential or a power supply potential from such a large-area ground conductor layer or power supply conductor layer to the semiconductor integrated circuit element, a stable ground potential or power supply potential can be supplied and a ground conductor layer or The power supply conductor layer serves as an electromagnetic shield, and prevents electromagnetic noise from entering the signal conductor layer from the outside and unnecessary electromagnetic noise from being emitted to the outside.
[0004]
In addition, in the wiring board in which the grounding conductor layer and the power supply conductor layer are provided in a pattern with a wide area over almost the entire surface of a certain insulating layer, the grounding conductor layer, the power supply conductor layer, the signal conductor layer, It is necessary to provide a through conductor for electrically connecting the electrode pad on the surface of the insulating substrate across a plurality of insulating layers through the grounding conductor layer and the power supply conductor layer. An opening surrounding the through conductor is provided at a portion where the through conductor penetrates the layer and the power conductor layer in order to prevent an electrical short circuit between the through conductor and the ground conductor layer or the power conductor layer. Furthermore, in the opening, a conductor pattern called a circular connection land having a diameter larger than that of the through conductor is formed at regular intervals from the ground conductor layer and the power conductor layer. Lead to land Are electrically connected between the upper and lower through-conductors each other through the grounding conductive layer and the power supply conductor layer made favorable by connecting. In addition, the through conductor connecting the grounding conductor layer or the power source conductor layer and the electrode pad has, for example, 3 for one electrode pad in order to stably supply the ground potential or the power source potential to the semiconductor integrated circuit element. In some cases, three through conductors are connected to one circular connection land.
[0005]
[Problems to be solved by the invention]
However, with the recent ultra-high integration of semiconductor integrated circuit elements, the wiring board is also required to have a high-density array of electrode pads. For this reason, a product having a narrow electrode pad array pitch of 1 mm or less is manufactured. It has come to be. When, for example, three through conductors are connected to such high-density electrode pads, the distance between the circular connection lands to which the three through conductors are connected becomes extremely narrow. It becomes impossible to provide a ground or power source conductor layer with a sufficient width between the connection lands. Then, the effective inductance of the ground or power supply conductor layer for supplying the ground or power supply potential to the semiconductor integrated circuit element becomes large, and as a result, the uniform from the ground or power supply conductor layer to the semiconductor integrated circuit element, In addition, since efficient grounding or power supply potential cannot be supplied, the semiconductor integrated circuit device has a problem of malfunction.
[0006]
The present invention has been devised in view of such conventional problems, and the purpose thereof is to provide a ground or power supply conductor layer with a large width between connection lands to which a plurality of through conductors are connected, As a result, it is an object of the present invention to provide a wiring board capable of normally operating a semiconductor integrated circuit element to be mounted by reducing the effective inductance of a ground or power source conductor layer.
[0007]
[Means for Solving the Problems]
The wiring board according to the present invention includes an insulating substrate formed by laminating a plurality of insulating layers, one of the insulating layers, a ground or power supply layer having a plurality of openings, and each opening. A plurality of connection lands disposed at a predetermined distance from the ground or power supply layer, and a plurality of through conductors disposed so as to penetrate the insulating layer and connect to the connection lands. The connection lands are triangular, and the adjacent connection lands are adjacent to each other at the corners of one connection land and the other connection land. A line segment connecting the center of the land is arranged so as to intersect with a side portion of the other connection land, and the through conductor is connected to each corner portion thereof. .
[0008]
According to the wiring board of the present invention, the connection land provided in the opening of the ground or power supply conductor layer and spaced apart from the ground or power supply conductor layer at a constant interval is a triangle and its adjacent connection land. Between each other, the line segment connecting the corner of one connection land closest to the other connection land and the center of the other connection land intersects with the side of the other connection land, In addition, since the through conductors are connected to the respective corners, it is possible to connect three through conductors to each connection land and to form a large space between the connection lands. In the meantime, a ground or power source conductor layer can be formed with a large width.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Next, the wiring board of the present invention will be described in detail with reference to the accompanying drawings.
[0010]
FIG. 1 is a cross-sectional view showing an example of an embodiment in which the wiring board of the present invention is applied to a wiring board used as a semiconductor element mounting board for mounting a semiconductor element integrated circuit element. The substrate 3 is a ground or power source conductor layer, 5 is a through conductor, and 6 is a connection land.
[0011]
The insulating substrate 1 is made of, for example, an inorganic insulator such as an aluminum oxide sintered body, an aluminum nitride sintered body, a mullite sintered body, a silicon carbide sintered body, a silicon nitride sintered body, a glass-ceramics, or an epoxy. 4 layers of insulating layers 1a, 1b, 1c, 1d made of organic insulators such as resin, polyimide resin, modified polyphenylene ether resin, bismaleimide triazine resin, etc. are laminated and integrated. A mounting portion on which the circuit element is mounted is formed, and a lower surface thereof forms a connection surface connected to the external electric circuit board.
[0012]
Such an insulating substrate 1 is suitable for a ceramic raw material powder such as aluminum oxide if each insulating layer 1a, 1b, 1c and 1d is made of an inorganic insulator such as an aluminum oxide sintered body. A binder and a solvent are added and mixed to form a slurry, and this is formed into a sheet by using a conventionally known doctor blade method, and ceramic green sheets to be the insulating layers 1a, 1b, 1c, and 1d are prepared. Thereafter, these ceramic green sheets are appropriately punched and laminated in a predetermined order to form a ceramic green sheet laminate for the insulating substrate 1, and finally the ceramic green sheet laminate is fired at a high temperature. On the other hand, each insulating layer 1a, 1b, 1c, 1d is made of an organic insulating material such as an epoxy resin. In the case, each of the insulating layers 1a, 1b, 1c, thereby preparing a thermosetting resin sheet of uncured for 1d by stacking them in a predetermined order is produced by thermally curing. In addition, you may contain glass fiber and an inorganic insulator filler in this thermosetting resin sheet.
[0013]
Further, a signal conductor layer 2 for inputting / outputting signals to / from the semiconductor integrated circuit element is attached to a predetermined wiring pattern between the insulating layers 1a and 1b of the insulating base 1, and the insulating layers 1b and 1c are provided. Between 1 and 1c and 1d, a ground or power supply conductor layer 3 for supplying a ground or power supply potential to the semiconductor integrated circuit element is applied over substantially the entire surface. Further, an electrode pad 4a for element connection to which each electrode of the semiconductor integrated circuit element is connected is provided on the upper surface of the insulating substrate 1, and an external connection electrode connected to the wiring conductor of the external electric circuit board is provided on the lower surface of the insulating substrate 1. An electrode pad 4b is applied. The electrode pads 4a and 4b are electrically connected to the signal conductor layer 2 and the ground or power source conductor layer 3 through a through conductor 5 that penetrates the insulating layers 1a, 1b, 1c, and 1d. The ground or power supply conductor layer 3 deposited between the insulating layers 1b and 1c and between 1c and 1d is a conductor for supplying different ground potentials or power supply potentials to the semiconductor integrated circuit element. Is a layer. In order to prevent an electrical short circuit with the ground conductors 3 connected to the other ground or power conductor layers 3 and the signal conductor layers 2, the ground or power conductor layers 3 pass through the ground or power conductor layers 3. An opening 3a surrounding the conductor 5 is formed, and a connection land 6 for improving the electrical connection between the upper and lower through conductors 5 is fixed in the opening 3a from the ground or power supply conductor layer 3. They are formed at intervals. The ground or power supply conductor layer 3 and the corresponding electrode pad 4b are connected by, for example, three through conductors 5 so that the ground or power supply potential can be supplied more efficiently. Yes.
[0014]
The signal conductor layer 2 and the ground or power source conductor layer 3, the electrode pads 4a and 4b, the through conductor 5, and the connection land 6 have insulating layers 1a, 1b, 1c, and 1d made of an aluminum oxide sintered body or the like. If it is made of an inorganic insulator, it consists of metal powder metallization such as tungsten, molybdenum, copper, silver, etc., and insulates the metal paste obtained by adding and mixing an appropriate organic binder and solvent to metal powder such as tungsten. The ceramic green sheets for the layers 1a, 1b, 1c, and 1d are formed by applying a screen printing method known in the art and firing the ceramic green sheets together with the ceramic green sheet laminate for the insulating substrate 1, On the other hand, if the insulating layers 1a, 1b, 1c, 1d are made of an organic insulator such as an epoxy resin, for example, copper foil or copper plating It consists of a cured copper paste, and a copper foil or copper plating layer is deposited on the sheets for the insulating layers 1a, 1b, 1c, and 1d, and it is etched into a predetermined pattern using a photolithography technique. Alternatively, it is formed by printing or filling a copper paste in a predetermined pattern and thermosetting it.
[0015]
Further, in the wiring board of the present invention, as shown in the plan view of the main part in FIG. 2, three through conductors 5 that connect the ground or power source conductor layer 3 and the corresponding electrode pad 4b are connected. The shape of the connecting land 6 is a triangle. Further, in the adjacent connection lands 6, the line segment connecting the corner of one connection land 6 closest to the other connection land 6 and the center of the other connection land 6 is the other connection land 6. It arrange | positions so that it may cross | intersect a side part, ie, it arrange | positions so that the corner | angular part of adjacent connection land 6 may not mutually face in front. Further, the through conductor 5 is connected to each corner of the connection land 6.
With this configuration, a large space is formed between adjacent connection lands 6, and the ground or power supply conductor layer 3 can be disposed with a large width therebetween.
Therefore, according to the wiring board of the present invention, it is possible to normally operate the mounted semiconductor integrated circuit element with the effective inductance of the ground or power supply conductor layer 3 being small.
[0016]
The through conductor 5 connected to each corner of the connection land 6 is preferably connected to a position 20 to 50 μm inside from the outer periphery of the connection land 6. When the through conductor 5 is located less than 20 μm inside from the outer periphery of the connection land 6, there is a risk that the connection reliability between the through conductor 5 and the connection land 6 becomes low. Since the area of the connection land 6 needs to be increased correspondingly, it tends to be difficult to arrange the connection lands 6 at a high density.
[0017]
Moreover, it is preferable that the space | interval of the connection lands 6 is the range of 30-100 micrometers. When the distance between the connection lands 6 is less than 30 μm, the electrical insulation reliability between the connection lands 6 tends to be low. On the other hand, when the distance between the connection lands 6 exceeds 100 μm, the connection lands 6 are arranged at a high density. Tend to be difficult.
[0018]
In addition, this invention is not limited to the above-mentioned embodiment, It goes without saying that various modifications are possible within a range not departing from the gist of the present invention.
[0019]
【The invention's effect】
According to the wiring board of the present invention, the connection land provided in the opening of the ground or power supply conductor layer and spaced apart from the ground or power supply conductor layer at a constant interval is a triangle and its adjacent connection land. Between each other, it is arranged so that a line segment connecting the corner of one connection land closest to the other connection land and the center of the other connection land intersects the side of the other connection land, In addition, since the through conductors are connected to the respective corners, three through conductors can be connected to each connection land, and a large interval can be formed between the connection lands. In the meantime, a ground or power source conductor layer can be formed with a large width.
Therefore, it is possible to provide a wiring board capable of normally operating a semiconductor integrated circuit element to be mounted, with the effective inductance of the ground or power supply conductor layer being small.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an example of an embodiment of a wiring board according to the present invention.
FIG. 2 is a plan view of an essential part of a wiring board according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Insulating substrate 1a-1d ... Insulating layer 3 ... Grounding or power supply conductor layer 3a ... Opening 5 of grounding or power supply conductor layer 3 .... Penetration conductor 6 ... Connection land

Claims (1)

An insulating substrate formed by laminating a plurality of insulating layers, a ground or power layer disposed in one of the insulating layers, having a plurality of openings, and constant from the ground or power layer in each opening. A wiring board comprising a plurality of connecting lands arranged at intervals of each other and a plurality of through conductors arranged so as to penetrate the insulating layer and connect to the connecting lands. In addition, the connection land is a triangle, and a line connecting the connection land adjacent to the other connection land and the center of the other connection land among the adjacent connection lands. A wiring board characterized in that a portion is arranged so as to intersect with a side portion of the other connection land , and the through conductor is connected to each corner portion.

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