JP2884669B2 - Glass ceramic multilayer wiring board - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a glass ceramic multilayer wiring board, and more particularly, to a structure of a peripheral portion of a glass ceramic substrate corresponding to an end of a polyimide to be laminated.

[Conventional technology]

Conventionally, on the surface of this type of glass ceramic substrate,
No processing was performed for the adhesion to the polyimide layer, and only the adhesion improving material was applied before applying the polyimide varnish.

[Problems to be solved by the invention]

In the above-described conventional glass ceramic substrate, when a polyimide layer is formed on the substrate surface, the density strength between the substrate and the polyimide film is not sufficient, and the glass ceramic substrate around the polyimide has a polyimide layer or a metal layer. There is a disadvantage that polyimide is peeled off at the interface due to being immersed in a chemical solution such as an acid or an alkali solution used for the formation.

Furthermore, when the polyimide is multi-layered and the film pressure is increased, the residual stress of the polyimide layer is concentrated on the end portion, and the glass ceramic substrate is cracked or broken by this stress.

[Means for solving the problem]

The glass-ceramic multilayer wiring board of the present invention, by forming a metal flange-shaped thing as a metal ring around the substrate under the interface of the polyimide layer to be laminated, adhesion strength between the substrate and the polyimide on the substrate surface, Occasionally, the adhesion strength at the interface is enhanced, and the glass ceramic at the interface of the polyimide layer on the lamination surface is protected from chemicals such as acids and alkalis, thereby preventing the polyimide layer from peeling off.

Further, it is characterized in that the residual stress of the polyimide layer concentrated on the edge of the substrate can be dispersed and the glass ceramic substrate having a lower strength than the alumina substrate can be prevented from cracking due to the stress.

〔Example〕

 Next, the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view of a glass-ceramic multilayer substrate having a metal ring in a peripheral portion according to an embodiment of the present invention.
The figure is a plan view thereof. After that, the glass ceramic substrate
It will be abbreviated as GCS.

As shown in the figure, a metal flange-shaped object is fixed so as to surround the side surface of the GCS 11, and a composite substrate having a metal ring 12 in a peripheral portion is formed. Then, a structure is adopted in which the end face of the polyimide 13 laminated on the substrate is placed on this metal ring. The material used for the metal ring 12 is aluminum,
Aluminum alloy, copper alloy, molybdenum, tungsten, Kovar, etc.

These metals are processed into flanges and shrink-fit to the sides of GCS11. After the shrink fitting, the lamination surface and the back surface of the composite material substrate are polished so that a step and a groove do not occur between the GCS 11 and the metal ring 12. Metal ring 12
Has a width of about 7 mm to 15 mm and a pressure equal to the thickness of the substrate.

GCS1 with metal ring on the periphery manufactured in this way
The results obtained by using 1 are shown below.

First, chemical resistance is described. The edge of the polyimide laminated on the substrate is not on the GCS11 but on the peripheral metal ring 1
Because of the structure above, even if GCS11 is attacked by a chemical such as acid or alkali, it has no effect on the polyimide interface. When using the conventional GCS having no metal ring, this is a great improvement compared to the case where GCS at the end of the polyimide layer is immersed in an acid or an alkaline solution and the polyimide is peeled off from the end according to lamination.

Next, the adhesion strength between the substrate and the polyimide will be described.

The adhesive strength of the polyimide 13 on the metal ring 12 is about 2.0 kg / _{6 mm} , whereas the adhesive strength of the polyimide on the GCS is about 1.0 kg / _{6 mm} when no stress is applied. By using the metal ring 12, the adhesion strength between the polyimide and the substrate at the interface is enhanced.

When polyimide is simply laminated on the GCS, a thick film of about 200 μm may peel off from the end of the polyimide layer or crack the GCS under the end face of the polyimide layer. This is a result of the residual stress of the multilayered polyimide being concentrated at the end, and the adhesion strength between the polyimide and the GCS or the strength of the GCS itself could not withstand this stress.

Using a GCS having a metal ring on the periphery of this example, even if the thickness of the polyimide exceeds 250 μm as a result of simple lamination with a structure in which the polyimide end is put on this metal ring, the end of the polyimide layer from the end No peeling or cracking of the substrate was observed. This is because the metal ring in the peripheral portion distributes the residual stress concentrated at the end.

〔The invention's effect〕

As described above, the present invention provides a metal ring by fixing a metal flange-shaped object to the periphery of the substrate under the interface of the polyimide layer laminated on the substrate, thereby forming a metal ring between the substrate and the polyimide. This has the effect of strengthening the adhesion strength at the interface, protecting the glass ceramic at the interface from chemicals such as acids and alkalis, and preventing peeling of the polyimide layer.

This metal ring also has the effect of dispersing the residual stress generated concentrated on the substrate edge by the multilayering of the polyimide, thereby preventing the glass ceramic substrate from being broken by the stress.

[Brief description of the drawings]

FIG. 1 is a sectional view of an embodiment of the glass ceramic substrate of the present invention, and FIG. 2 is a plan view thereof. 11 ... Glass ceramic substrate, 12 ... Metal ring, 13
... Polyimide layer.

Claims (1)

(57) [Claims] A glass-ceramic multilayer substrate having a conductor layer therein; a metal ring fixed to a side surface of the glass-ceramic multilayer substrate and formed so as to enclose the periphery of the substrate;
A glass-ceramic multilayer wiring board, comprising: a polyimide layer formed on a surface of the glass-ceramic multilayer board and having a rim extending over the metal ring.