JPH05267799A - Wiring board - Google Patents

Abstract

(57) [Abstract] [Purpose] Wiring (circuit) substrate suitable for mounting devices (LSI, electronic parts, etc.) suitable for high-frequency signal processing or high-speed signal processing, such as semiconductor devices that handle high-frequency signals and operate at high speed (EN) Provided is a wiring board which can be mounted and which can transmit a high frequency signal between wiring layers with high reliability. A wiring board (corresponding to a double-sided printed wiring board) having a plurality of electric conductor pattern wiring layers 2 and 3 on both sides of an insulating substrate 1 or a plurality of electric conductor pattern wiring layers 45 and 46 on one side or both sides Multiple insulator substrates 41-4
4 is a multilayered wiring board (corresponding to a multilayer printed wiring board), a through hole is provided in the vicinity of the electric conductor pattern wiring layer for transmitting a high frequency signal between the arranged wiring layers, Materials 4 and 47 having a dielectric constant higher than that of the insulating substrate are arranged in the through holes.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wiring (circuit) board, and more specifically, a wiring board suitable for mounting devices (LSI, electronic parts, etc.) suitable for high frequency signal processing or high speed signal processing. Regarding

[0002]

2. Description of the Related Art As a wiring board suitable for mounting an element for processing a high-frequency signal (for example, a microwave or millimeter wave level signal of about gigahertz or higher) or a high-speed signal processing, the wiring structure is usually a signal. A structure having a layer, a ground layer, and a power supply layer, and connecting these layers with an electric conductor material of a via hole as required is given.

Such a wiring board is an insulator (dielectric).
A predetermined wiring pattern layer may be formed on both surfaces of the substrate to form a double-sided printed wiring board, or these may be laminated in multiple layers to form a multilayer printed wiring board. In some cases, elements such as resistors, capacitors, and coils can be incorporated in the wiring board. To form a wiring (electrical conductor pattern) on an insulating substrate, a method of forming a conductor thin film on the entire surface by vapor deposition, sputtering, copper foil bonding, etc. on the substrate and forming a predetermined wiring pattern by a photoetching technique, or a conductor There is a method in which a paste is applied to a predetermined pattern by a printing technique and is baked to form a wiring pattern (thick film pattern). In addition, a ceramic green sheet, screen printing of a conductor paste on the green sheet, laminating and firing (sintering) to form a ceramic multilayer circuit board are also performed. There are a method of forming a through hole (via hole) in the base and performing a through hole plating and a method of filling an electric conductor material in order to make a wiring interlayer connection through the insulating substrate.

Further, as an example of application of a high dielectric constant material to a high frequency circuit, a high dielectric constant layer having an appropriate shape (size) is arranged at an appropriate position in the vicinity of a conductor pattern in a wiring board, so that a resonance caused by a dielectric substance is generated. It is known to be used as a container.

[0005]

In a microwave circuit or the like which handles a high frequency signal, the electric resistance of the electric conductor wiring may increase due to the skin effect, resulting in an increase in energy loss. In addition, a connection failure may occur in the through hole (via) of the interlayer connection, which may lead to a decrease in reliability.

An object of the present invention is to provide a wiring board which can mount a semiconductor element which handles a high frequency signal and operates at a high speed and which can transmit a high frequency signal between wiring layers with high reliability.

[0007]

SUMMARY OF THE INVENTION In the wiring board (corresponding to a double-sided printed wiring board) having a plurality of electric conductor pattern wiring layers on both sides of an insulating substrate, the above-mentioned object is to be achieved between wiring layers arranged on both sides. A through hole is provided in the vicinity of the electric conductor pattern wiring layer for transmitting a high frequency signal, and a material having a higher dielectric constant than the dielectric constant of the insulator substrate is arranged in the through hole. This is achieved by a characteristic wiring board.

Further, the above-mentioned object is that a plurality of insulating boards provided with a plurality of electric conductor pattern wiring layers on one or both sides are adjacent to each other in a multilayer wiring board (corresponding to a multilayer printed wiring board). An independent layer of a material having a dielectric constant higher than that of the insulating substrate is arranged between the electric conductor pattern wiring layers which are arranged on the opposite surfaces of the insulating substrate and for transmitting a high frequency signal. And /
Alternatively, a through-hole is provided in the vicinity of the electric conductor pattern wiring layer for transmitting a high-frequency signal, the through-hole being arranged with at least one insulator substrate sandwiched therebetween, and the through-hole having a higher dielectric constant than the insulator substrate. This is achieved by a wiring board characterized in that a material having a dielectric constant is provided.

It is preferable that the high dielectric constant material extends so as to cover a part of the electric conductor pattern wiring layer for transmitting a high frequency signal.

[0010]

In the present invention, a high frequency electric signal is transmitted between wiring layers by interposing a dielectric substance, and the electric field is likely to be concentrated in the vicinity of a relatively high dielectric constant material. Is used to transmit electromagnetic field fluctuations due to electric signals from one wiring layer to another wiring layer. In this case, it is possible to avoid an increase in electric resistance due to the skin effect in the via hole of the electric conductor and an accompanying energy loss.

Since the high dielectric constant material does not pass a direct current, it cannot be used for connecting the power supply layer or the ground layer to the signal layer, and these connections are performed as usual. When the size of the corresponding high dielectric constant material is sufficiently small compared to the wavelength (in the medium corresponding to the frequency band) of the electric signal, the circuit element functions as a capacitor. Then, when the size becomes large and the order is approximately the same as the wavelength of the electric signal, a resonator element appears. From these facts, if the wavelength of the electrical signal to be transmitted between the wiring layers is used as the reference, in the wavelength region that is sufficiently shorter than this reference wavelength,
Signal transmission becomes better as the frequency increases, and when the frequency region gradually approaches the reference wavelength, the signal transmission condition is greatly affected in the vicinity of the resonance wavelength.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the accompanying drawings by way of embodiments and comparative examples of the present invention. Example 1 A double-sided printed wiring board type wiring board according to the present invention is manufactured as follows.

As shown in FIGS. 1 (a) and 1 (b), a sintered alumina substrate is prepared as an insulator substrate 1 and has a diameter of 1 mm.
Drill through holes. A silver paste is screen-printed on both sides of this substrate, dried, and baked at 900 ° C. to form wiring layers 2 and 3 of an electric conductor pattern (eg, width 1 mm).
To form. Then, a wiring board is obtained by inserting a separately prepared cylindrical high dielectric constant material (for example, BaTiO ₃ ) 4 having a diameter of about 1 mm into the through hole. These wiring layers 2,
As shown in FIG. 1B, the positional relationship between the through holes 3 and the through holes (that is, the high dielectric constant material (pins) 4) is close to these wiring layers and in the middle position of the wiring layers in a plan view. It is in.

It is also possible to manufacture a wiring board having the same structure through another process. In this case, first make a green sheet with alumina as the main component, open a through hole,
BaTiO ₃ powder containing paste is filled there. This green sheet is dried and sintered to form an alumina substrate whose main component is. Then, the wiring layers 2 and 3 are formed by using the silver paste as described above.

Example 2 A wiring board having a structure in which a high dielectric material is added to the wiring board of Example 1 so as to cover a part of the wiring layer is manufactured as follows. As shown in FIGS. 2 (a) and 2 (b), a sintered alumina substrate is prepared as the insulating substrate 11, a through hole having a diameter of 1 mm is opened, and a silver paste is provided on both sides of this substrate in the vicinity of the through hole. Printing, drying and firing at 900 ° C. form the wiring layers 12 and 13 of the electric conductor pattern. Then, a separately prepared high dielectric constant material (eg, SrTiO ₃ ) on a cylinder with a diameter of about 1 mm
The through hole is filled with 14. Further, on the exposed surface of the through hole filling material 14 and a part of each wiring layer 12, 13, a thin piece 15 of a high dielectric constant material of the same kind as the through hole is formed.
And 16 are attached, and the wiring layers 12 and 13 are covered with the high dielectric constant materials 15 and 16.

Example 3 A multilayer printed wiring board type wiring board according to the present invention is manufactured as follows. As shown in FIGS. 3A and 3B, a plurality of MgO single crystal substrates 2 are used as insulator substrates.
1, 22 are prepared, a silver paste is screen-printed on one surface of each of the substrates 21, 22, dried and baked at 900 ° C. to form the wiring layers 23 and 24 of the electric conductor pattern. Then, a rectangular thin plate 25 of a high dielectric constant material (for example, SrTiO ₃ ) prepared separately is arranged near the wiring layers 23 and 24, and is sandwiched between the substrates 21 and 22 by using an appropriate adhesive, so that wiring is performed. A substrate is obtained. The shape of the high dielectric constant material is not limited to a rectangle, but may be a circle, a polygon, or the like.

Example 4 A multilayer printed wiring board type wiring board according to another aspect of the present invention is manufactured as follows. As shown in FIGS. 4 (a) and 4 (b), sintered alumina substrates 41, 42, 43, and 44 having the same outer dimensions are prepared as an insulating substrate, and through holes having a diameter of about 2 mm are made at the same set positions. On each of these substrates, a silver paste is screen-printed on one surface (or both surfaces), dried, and baked at 900 ° C. to form wiring layers 45 and 46 having a predetermined electric conductor pattern. In this case, only the wiring layers formed on the outer insulating substrates 41 and 44 are shown, and the other wiring layers are omitted. Then, as shown in FIG. 4A, these substrates 41 to 44 are stacked and fixed while keeping a small space, and a column 47 of a separately prepared high dielectric constant material (for example, SrTiO ₃ ) having a diameter of less than 2 mm is prepared. A wiring board can be obtained by inserting the wiring board into the through hole. The positional relationship between the wiring layers 45 and 46 and the through holes (that is, the high dielectric constant material cylinder 47) is as shown in FIG. It is in the middle position. A resistor, a capacitor, and a coil can be arranged in the space.

[0018]

As described above, the wiring board provided with the interlayer connection portion of the high dielectric constant material according to the present invention has an effect that high-frequency signals can be stably transmitted between the wiring layers. Furthermore, it is possible to add a function of blocking a direct current component between wiring layers and a function of an electric filter depending on the shape, size and frequency of the high dielectric constant material.

[Brief description of drawings]

1A is a schematic cross-sectional view of a double-sided printed wiring board type wiring board according to the present invention, and FIG. 1B is a partial plan view thereof.

FIG. 2A is a schematic cross-sectional view of another double-sided printed wiring board type wiring board according to the present invention, and FIG. 2B is a partial plan view thereof.

FIG. 3 (a) is a schematic cross-sectional view of a multilayer printed wiring board type wiring board according to the present invention, and FIG. 3 (b) is a partial plan view thereof.

FIG. 4A is a schematic sectional view of another wiring board of the present invention of a multilayer printed wiring board type, and FIG. 4B is a partial plan view thereof.

[Explanation of symbols]

 1, 11 ... Insulator substrate (alumina substrate) 2, 3, 12, 13 ... Wiring layer 4, 14 ... High dielectric constant material 21, 22 ... Insulator substrate 23, 24 ... Wiring layer 25 ... High dielectric constant material 41 , 42, 43, 44 ... Insulator substrate (alumina substrate) 45, 46 ... Wiring layer 47 ... High dielectric constant material

Claims (4)

[Claims] 1. A wiring board having a plurality of electric conductor pattern wiring layers on both sides of an insulating board, wherein the electric conductor pattern wiring layers (2, 2) for transmitting a high frequency signal between the wiring layers arranged on both sides. A wiring board, wherein a through hole is provided in the vicinity of 3), and a material (4) having a dielectric constant higher than that of the insulating substrate is arranged in the through hole. 2. A wiring board in which a plurality of insulating boards having a plurality of electric conductor pattern wiring layers on one side or both sides are stacked to form a multilayer structure, and the adjacent insulating boards (21, 21,
22) between the electric conductor pattern wiring layers (23, 24) arranged on the opposite surfaces and for transmitting a high frequency signal, the material having a higher dielectric constant than that of the insulating substrate is independent. A wiring board having a layer (25) provided thereon. 3. A wiring board in which a plurality of insulating boards having a plurality of electric conductor pattern wiring layers on one surface or both surfaces thereof are stacked to form a multilayer, and at least one of the insulating boards (41, 42, 43, 44). ), And a through hole is provided in the vicinity of the electric conductor pattern wiring layer (45, 46) for transmitting a high frequency signal, and the through hole has a higher dielectric constant than the insulator substrate. A wiring board provided with a material (47) having a dielectric constant. 4. The high dielectric constant material extends so as to cover a part of the electric conductor pattern wiring layer for transmission of a high frequency signal. The wiring board according to any one of 1.