JPH0537103A - Ceramic board - Google Patents

Abstract

(57) [Summary] [Object] With regard to a glass ceramic substrate, an object thereof is to provide a glass ceramic substrate capable of preventing peeling of a polyimide layer formed on the surface of the glass ceramic substrate body. [Structure] On a surface of a substrate body 2 of a glass ceramic substrate 1, an adhesive pattern 4 is formed on a peripheral portion of an insulating layer 3 laminated on the surface so as to secure adhesive strength between the substrate body 2 and the insulating layer 3. To do. Further, the adhesive pattern 4 is connected to the dummy via conductor 5 provided in the substrate body 2 so as to obtain an anchoring effect. Further, the dummy via conductor 5 is connected to the thick film pattern 10 provided in the substrate body 2 so as to enhance the anchoring effect.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ceramic substrate, and more particularly to a ceramic substrate having an adhesive pattern for preventing peeling of a thin film of a glass ceramic substrate.

[0002]

2. Description of the Related Art Conventionally, in a glass ceramic substrate, for example, a surface mount component is mounted on the surface thereof. Therefore, for example, as shown in FIG. For example, 3 to 7 μm depending on a thin film forming method such as coating.
A collector (conductor pattern) 103 having a film thickness of about m is formed, and a polyimide layer 105 as an insulating layer having a film thickness of about 20 to 40 μm is further formed. The polyimide layer 105 is photographed at a position corresponding to the collector 103. By forming the hole 104 and then forming the conductor pattern 106 for mounting the surface mount component on the surface of the polyimide layer 105 by a thin film forming method, the misalignment between the via hole 107 of the substrate body 102 and the component mounting position is eliminated. There is technology. In practice, one layer or a plurality of layers of intermediate conductor patterns alternately laminated between the polyimide layer 105 in contact with the collector 103 and the conductor pattern 106 on the surface and the same number of other polyimide layers are provided, and each layer is provided. Via hole 107 and collector 1 while gradually shifting the position of the intermediate conductor pattern of
03 and the position of the conductor pattern 106 on the surface on which the component is mounted are eliminated, but in order to simplify the explanation, these intermediate conductor patterns and the same number of other polyimide layers will be omitted.

The polyimide layer 105 is formed by printing liquid polyimide and then heating it at 350 to 450 ° C. for about 30 to 180 minutes to cure it.

[0004]

By the way, when the polyimide layer 105 is heated and cured, the polyimide layer 10
Internal stress that causes the polyimide layer 105 to contract is generated in the substrate 5, and an organic solvent component containing sodium ions that deteriorates the polyimide layer 105 emerges from the substrate body 102. Due to the synergistic effect of the internal stress of the polyimide layer 105 and the alteration of the polyimide layer 105 by sodium ions, there is a problem that the polyimide layer 105 is separated from the substrate main body 102 at the peripheral portion of the polyimide layer 105 where the internal stress is most concentrated. Has occurred. This problem is a phenomenon that is particularly prominent in glass ceramics, but it naturally occurs not only in glass ceramic substrates but also in ceramic substrates containing Natriumum as a constituent element.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a ceramic substrate capable of preventing peeling of a polyimide layer as an insulating layer from the ceramic substrate.

[0006]

In order to achieve the above object, the present invention comprises a thin film layer laminated on the surface of a substrate body 2 of a ceramic substrate 1, as shown in FIG. 1, for example. The insulating layer 3 corresponding to the peripheral edge of the insulating layer 3
The adhesive pattern 4 for securing the adhesive strength between the substrate main body 2 and the substrate main body 2 is formed. It is preferable that the adhesive pattern 4 is provided with a dummy via conductor 5 connected to the adhesive pattern 4. Further, it is preferable to form the thick film pattern 10 in the substrate body 2 and connect the dummy via conductor 5 to the thick film pattern 10.

[0007]

In the present invention, since the adhesive pattern 4 is interposed between the substrate body 2 and the insulating layer 3, the substrate body 2
The bonding strength between the adhesive pattern 4 and the bonding pattern 4 and the bonding strength between the bonding pattern 4 and the insulating layer 3 are stronger than the direct bonding strength between the substrate body 2 and the insulating layer 3. If the adhesive pattern 4 is connected to the dummy via conductor 5 provided in the substrate body 1, the adhesive pattern 4 is prevented from peeling together with the surface portion of the substrate body 2 due to the anchoring action of the dummy via conductor 5. . By connecting the dummy via conductor 5 to the thick film pattern 10 formed in the substrate body 2, the anchoring effect can be further enhanced.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention in which the ceramic substrate is a glass ceramic substrate will be described below with reference to FIGS.

As shown in FIG. 1, the glass-ceramic substrate 1 is a multi-layer substrate produced by a so-called green sheet method, and has a substrate body 2 whose surface is polished and a substrate body 2 formed on the surface thereof. A collector 7 and an adhesive pattern 4, a polyimide layer 3 as an insulating layer covering the collector 7, and a surface conductor pattern 9 formed on the surface of the polyimide layer 3 around a hole 8 formed in the polyimide layer 3 by a photographic method. Is equipped with.

In practice, a plurality of layers of intermediate conductor patterns and a plurality of layers of another polyimide layer, which are alternately laminated, are provided between the polyimide layer 3 and the surface conductor pattern 9.
Here, for simplification of description, these intermediate conductor patterns and a plurality of other polyimide layers are omitted.

The collector 7 and the adhesion pattern 4 are made by depositing, for example, chromium (Cr), molybdenum (Mo), platinum (Pt) or the like on the surface of the substrate body 2 by a thin film forming method such as vapor deposition, sputtering or ion plating. Formed by. The film thickness of the collector 7 is, for example, about 3 to 7 μm in order to ensure conductivity, and the film thickness of the adhesive pattern 4 is sufficient to withstand the internal stress of the polyimide layer 3 generated when the polyimide layer 3 is heat-cured. It suffices that the mechanical strength be secured, and for example, it is set to about the thickness of the polyimide layer 3 or less. Also, the adhesive pattern 4
Area is such that the bonding strength between the adhesive pattern 4 and the polyimide layer 3 is not separated by the internal stress of the polyimide layer 3 generated when the polyimide layer 3 is heated and cured, for example, a width of 5 mm.
You can set it to.

As shown in FIG. 2, the adhesive pattern 4 is continuously formed corresponding to the entire circumference of the peripheral edge portion of the polyimide layer 3, and as shown in FIG. 1, a dummy via provided in the substrate body 1 is formed. It is connected to the conductor 5.

The dummy via conductor 5 is formed in the same manner as the normal via conductor 11 is formed when the substrate body 2 is formed.
Copper (Cu) in the via hole opened in the green sheet,
A fine powder of molybdenum (Mo), gold (Au) or the like, or a paste obtained by kneading this with an organic solvent is filled, and the mixture is laminated and sintered.

The numbers, diameters, depths and distribution densities of the dummy via conductors 5 are designed in relation to each other so as to obtain an anchoring force that can resist peeling of the polyimide layer 3. However, as shown in FIG. 1, the thick film pattern 1 is formed in the substrate body 2.
When 0 is provided and the inner end of the dummy via conductor 5 is connected to the thick film pattern 10, since the anchoring action of the dummy via conductor 5 is significantly enhanced by the thick film pattern 10, the depth of the dummy via conductor 5 is set to the substrate. It is not necessary to provide it over the entire thickness of the main body 1. For example, in the case of the dummy via conductor 5 having a diameter of 90 μm, it may be provided within the range of 2 to 3 or more layers on the front side. In this case, it is not preferable to make the depth of the dummy via conductor 5 shallower than the two or three layers of the green sheet, because it becomes difficult to obtain the necessary anchoring force. This is not preferable because the increase in the effect is small despite the increase in the material.

The thick film pattern 10 has copper (Cu), molybdenum (M) on the surface of the green sheet, similar to the case where the inner layer conductor pattern is formed when the substrate body 2 is formed.
o), fine powder of gold (Au) or the like is kneaded together with an organic solvent, and a paste is printed and laminated and then sintered. The film thickness of the thick film pattern 10 is set to, for example, about 50 μm.

The polyimide layer 3 is formed by applying liquid polyimide and heating it at 350 to 450 ° C. for 30 to 180 minutes to cure it. After this curing, holes 8 are formed in the position corresponding to the collector 7 by a photographic method. The thickness of the polyimide layer 3 is set to 20 in order to secure insulation.
It is set to about 40 μm.

Similarly to the collector 7, the surface conductor pattern 9 is formed by a thin film forming method such as sputtering, and is connected to the collector 7 by a conductor which is sputtered inside the hole 8 when the thin film forming method is formed.

In this glass ceramic substrate 1,
Since the peripheral portion of the polyimide layer 3 is bonded to the substrate body 2 via the adhesive pattern 4, the bonding strength between the polyimide layer 3 and the adhesive pattern 4 and the bonding strength between the adhesive pattern 4 and the substrate body 2 are the same as those of the polyimide layer 3. Bonding can be made stronger than the bonding strength when bonded to the substrate body 2, and organic solvent components, particularly sodium ions, that come out of the substrate body 2 when the polyimide layer 3 is heated and cured are blocked by the adhesive pattern 4, There is no risk of the layer 3 being altered by sodium ions, and the polyimide layer 3 is firmly bonded to the surface of the substrate body 2 via the adhesive pattern 4.

Further, since the adhesive pattern 4 is connected to the dummy via conductor 5 provided in the substrate body 2, the adhesive pattern 4 tries to float from the substrate body 2 together with the surface of the substrate body 2. The dummy via conductor 5 exerts an anchoring action like a pile, and prevents the adhesive pattern 4 from floating from the substrate body 2. The anchoring action of the dummy via conductor 5 is further enhanced by connecting the inner ends of the dummy via conductors 5 to the thick film pattern 10, and the polyimide layer 3 is firmly bonded to the surface of the substrate body 2 via the adhesive pattern 4. Together, it was possible to reliably prevent the polyimide layer 3 from peeling and the surface of the substrate body 2 together with the polyimide layer 3 and the adhesive pattern 4 from peeling off.

Although the glass-ceramic substrate has been described above as an example, the present invention can of course be applied to other ceramic substrates having sodium as a constituent element.

[0021]

As described above, according to the present invention, the peripheral portion of the insulating layer is firmly bonded to the surface of the substrate body through the adhesive pattern. Further, when the adhesive pattern is connected to the dummy via, the adhesive stress of the dummy via conductor causes the adhesive pattern to float up from the substrate body together with the surface of the substrate body due to the internal stress of the insulating layer generated when the insulating layer is heated and cured. Since this is prevented, it is possible to prevent the insulating layer from peeling off during heat curing.

Further, when the insulating layer is heated and cured, organic solvent components such as sodium ions, which are emitted from the substrate body, are blocked by the adhesive pattern, and the insulating layer is denatured by the organic solvent components such as sodium ions and the insulating layer and the substrate body are separated from each other. Since there is no possibility of lowering the bonding strength of (1), peeling of the insulating layer during heat curing can be prevented more reliably.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of an embodiment of the present invention.

FIG. 2 is a plan view of an embodiment of the present invention.

FIG. 3 is a schematic cross-sectional view of a conventional example.

[Explanation of symbols] 1 Ceramic substrate (glass ceramic substrate) 2 Board body 3 Polyimide layer (insulating layer) 4 Adhesion pattern 5 Dummy via conductor 10 thick film pattern

Claims (3)

[Claims] 1. An insulating layer constituting a thin film layer laminated on the surface of a substrate body (2) of a ceramic substrate (1).
Corresponding to the peripheral portion of (3), the insulating layer (3) and the substrate body
A ceramic substrate having an adhesive pattern (4) for ensuring adhesive strength with (2). 2. The ceramic substrate according to claim 1, further comprising a dummy via conductor (5) connected to the adhesive pattern (4). 3. A thick film pattern (10) in the substrate body (2).
To form a thick film pattern (10)
The ceramic substrate according to claim 1, which is connected to.