JPH0774475A - Mesh pattern structure - Google Patents

Abstract

PURPOSE:To provide a mesh pattern structure not restricted by manufacturing technology, with improved electrical characteristics suitable for the use as the ground layer or the power supply layer of a multilayer substrate. CONSTITUTION:First and second mesh patterns 6 and 12 consisting of a conductor with a plurality of openings each are laminated via an interlayer insulation layer 10, the first and second mesh patterns 6 and 12 are electrically connected through a via 10A on the interlayer insulation layer 10, and the openings 6A and 12A of the first and second mesh patterns and the via 10A are located at different positions in terms of plane.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mesh pattern structure suitable for use as a ground layer or a power layer of a multi-layer substrate.

A multi-layer substrate using ceramics such as alumina or a thin-film multi-layer substrate using polyimide resin is suitable for forming a circuit for processing a high-speed signal. Multilayer substrates for high-speed circuits usually have a stripline structure or a triplate structure. In this type of multi-layer substrate structure, a ground layer and a power supply layer that have good electrical characteristics and are not restricted by manufacturing techniques are required.

[0003]

2. Description of the Related Art FIG. 4 is a perspective view showing a conventional mesh pattern structure which can be used as a ground layer or a power supply layer in a multilayer substrate. Reference numeral 2 represents a mesh pattern made of a conductor having a plurality of openings, and reference numeral 4
Represents an insulating layer made of polyimide or the like that supports the mesh pattern 2.

When this mesh pattern structure is used as a ground layer or a power supply layer of a multi-layer substrate, the existence of openings in the mesh pattern 2 is originally not preferable in terms of electrical characteristics. Nevertheless, the reason why the mesh pattern 2 having such an opening is used is to remove the binder in the ceramic multilayer substrate in the manufacturing process of the multilayer substrate, and in the copper polyimide thin film multilayer substrate, This is because it is necessary for venting the gas generated when baking the polyimide.

In the copper polyimide substrate, attention is paid to the fine pattern and the opening is made as small as possible, but this is not sufficient because there is a limit in patterning. Further, in the case of forming a strip line with the mesh pattern as the ground layer, for example, when forming the signal line in the upper layer,
Since the signal line cannot be formed in the portion corresponding to the opening of the mesh pattern, there is a problem that the restriction of pattern formation becomes large, and the pattern formation cannot be performed by making full use of the miniaturization of the wiring board.

[0006]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a mesh pattern structure which is not restricted by the manufacturing technique and has good electric characteristics. It is also an object of the present invention to provide a multilayer substrate using this mesh pattern structure.

[0007]

According to the present invention, there is provided a structure in which first and second mesh patterns made of conductors each having a plurality of openings are laminated with an interlayer insulating layer interposed therebetween. The first and second mesh patterns are electrically connected to each other through vias provided in the interlayer insulating layer, and the openings of the first and second mesh patterns and the vias are at different positions in plan view. Structure is provided.

[0008]

In the mesh pattern structure of the present invention, since the first and second mesh patterns each have a plurality of openings, when the mesh pattern structure is formed on the insulating layer, the binder removal (the insulating layer is Since it can be made of ceramics or can be degassed (when the insulating layer is a resin such as polyimide), there is no restriction on the manufacturing technology.

Further, since the openings of the first and second mesh patterns are arranged at different positions in plan view,
When forming the upper layer signal line, there is no restriction due to the opening of the first or second mesh pattern, and the electrical characteristics are good.

In the structure of the present invention, the first and second
The openings of the mesh pattern and the vias are provided at different positions in plan view. When the vias are at the same positions as the openings of the first or second mesh pattern, the first and second vias are provided through the vias. This is because the two mesh patterns cannot be electrically connected.

[0011]

EXAMPLES Examples of the present invention will be described below. 1 is a perspective view of a mesh pattern structure showing an embodiment of the present invention, FIG.
Is a plan view thereof, and FIG. 3 is a sectional view thereof. In FIG. 3, (A) represents a cross section taken along the line AA ′ of FIG.
2B shows a cross section taken along the line BB ′ of FIG. In addition, this example is an example in which the mesh pattern structure of the present invention is applied to a copper polyimide substrate.

The first mesh pattern 6 made of copper is formed on the lower polyimide layer 8, and the lower polyimide layer 8 is partially exposed by the plurality of openings 6A provided in the first mesh pattern 6. Therefore, the opening 6A of the first mesh pattern 6 serves as a gas vent hole from the lower polyimide layer.

An intermediate polyimide layer (interlayer insulating layer) 10 connected to the lower polyimide layer 8 through the opening 6A is formed on the first mesh pattern 6. The intermediate polyimide layer 10 has a via 10A for connecting the first mesh pattern 6 and the second mesh pattern 12.
Are formed.

A second layer formed on the intermediate polyimide layer 10.
The mesh pattern 12 is also made of copper, and the second mesh pattern 12 is electrically connected to the first mesh pattern 6 via the via 10A. The second mesh pattern 12 is provided with an opening 12A as a hole for venting gas from the intermediate polyimide layer 10. The opening 12A of the second mesh pattern is formed at a position different from the opening 6A of the first mesh pattern 6 in plan view. That is, when this mesh pattern structure is seen through from above, the openings 6A of the first mesh pattern 6 and the openings 12A of the second mesh pattern 12 do not overlap.

Each layer can be formed by, for example, a photolithography method. The gas generated from the lower polyimide layer 8 at the time of manufacturing is transferred to the second polyimide through the intermediate polyimide layer 10.
Is discharged to the outside from the opening 12A of the mesh pattern 12. Therefore, there is no possibility that the conductor pattern will be damaged due to the gas release. Further, since the openings 6A of the first mesh pattern 6 and the openings 12A of the second mesh pattern 12 are at different positions in plan view, this mesh pattern structure has a solid ground layer or a power source having no complete perforations. It can be seen as a layer and the electrical properties are greatly improved.

In the embodiments described above, the example in which the mesh pattern structure of the present invention is applied to a copper polyimide substrate has been described, but the present invention can be applied to a multilayer substrate using an inorganic material such as alumina or glass ceramics. is there.

[0017]

As described above, according to the present invention,
There is an effect that it is possible to provide a mesh pattern structure having good electric characteristics without being restricted by manufacturing technology.

[Brief description of drawings]

FIG. 1 is a perspective view of a mesh pattern structure showing an embodiment of the present invention.

FIG. 2 is a plan view of a mesh pattern structure showing an embodiment of the present invention.

FIG. 3 is a cross-sectional view of a mesh pattern structure showing an embodiment of the present invention.

FIG. 4 is an explanatory diagram of a conventional technique.

[Explanation of symbols]

 6 First Mesh Pattern 8 Lower Polyimide Layer 10 Intermediate Polyimide Layer (Interlayer Insulating Layer) 12 Second Mesh Pattern

Claims (3)

[Claims] 1. A structure in which first and second mesh patterns (6, 12) made of conductors each having a plurality of openings are laminated with an interlayer insulating layer (10) interposed therebetween. And the second mesh pattern (6, 12) are electrically connected through the via (10A) provided in the interlayer insulating layer (10), and the first and second mesh patterns (6, 12) The mesh pattern structure in which the openings and the vias (10A) are at different positions in a plane. 2. The multilayer substrate having a mesh pattern structure according to claim 1, wherein the interlayer insulating layer (10) is made of an inorganic material. 3. The thin film multilayer substrate having a mesh pattern structure according to claim 1, wherein the interlayer insulating layer (10) is made of a polyimide resin.