JPH025023B2 - - Google Patents

Description

[Detailed description of the invention] [Technical field to which the invention pertains] The present invention relates to a thick film multilayer wiring board.

[Prior art]

Conventionally, thick film multilayer wiring boards have a multilayer structure using conductive paste and insulating paste on a ceramic substrate. A lower conductor layer is formed using a conductive paste, a lower insulating layer is formed using an insulating paste, an intermediate conductor layer is formed on the lower insulating layer, and an upper insulating layer is further formed on top of the lower insulating layer. When attempting to create a multilayer structure by repeating the process of forming layers, an opening is created in advance in the lower insulating layer to connect the lower conductor layer and the intermediate conductor layer, and conductive paste is inserted into this opening to make the connection. Since the upper insulating layer above the connection opening is easily formed with pinholes, pinholes are likely to form between the upper conductor layer formed above the connection opening and sandwiching the upper insulating layer. The drawback was that it occasionally caused electrical short circuits.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a thick film multilayer wiring board that eliminates the above drawbacks and eliminates short circuits between the upper conductor layer and the lower or intermediate conductor layer.

[Structure of the invention]

The present invention provides a lower conductor layer provided on an insulator layer or on a substrate whose surface is at least an insulator;
a lower insulating layer formed to cover at least the lower conductor layer; a connection opening provided in the lower insulating layer so as to be located on the lower conductor layer;
an intermediate conductor layer provided on the lower insulating layer and connected to the lower conductor layer through the opening;
In a thick film multilayer wiring board formed by repeating an upper insulating layer provided to cover at least the intermediate insulating layer and an upper conductive layer provided on the upper insulating layer, the lower conductive layer and The structure is characterized in that a notch removal portion is provided in the upper conductor layer portion located above the opening to be connected to the intermediate conductor layer.

[Explanation of Examples]

FIGS. 1a and 1b are a plan view and a sectional view taken along line A-A' of an embodiment of the present invention.

A lower conductor layer 2 is provided on a ceramic substrate 1,
A lower insulating layer 3 is provided to at least cover this lower conductor layer 2. A connection opening 4 is provided in the lower insulating layer 3, and the opening 4 is filled with, for example, a conductive paste 5. Then, an intermediate conductor layer 6 is provided on the lower insulating layer 3. Then, the intermediate conductor layer 6 is electrically connected to the lower conductor layer 2 via the conductor paste 5. next,
An upper insulating layer 7 is provided to cover the intermediate conductor layer 6. After that, an upper conductor layer 8 is formed on the upper insulating layer 7.
will be established. At this time, a notch removal portion 9 is provided in the portion of the upper conductor layer 8 located above the opening 4 that serves as the connection portion between the lower conductor layer 2 and the intermediate conductor layer, so that no conductor layer is present. Providing this notch removal portion 9 is a feature of the present invention.

With this structure, even if there is a pinhole in the upper insulating layer 7 above the opening 4, the upper conductor layer 8 will not be formed at the pinhole, so the upper conductor layer 8 will fill the pinhole. A short circuit to the intermediate conductor layer 6 does not occur. This eliminates the drawbacks of the prior art.

In the above embodiment, the layer immediately above the substrate was described, but the present invention is also applicable to multilayer wiring in which an insulating layer and a conductor layer are stacked on top of the upper conductor layer 8.
In this case, the upper conductor layer 8 is regarded as a lower conductor layer or an intermediate conductor layer.

〔Effect of the invention〕

As explained in detail above, according to the present invention,
The effect is great because a thick film multilayer wiring board can be obtained that prevents short circuits between the upper conductor layer and the intermediate conductor layer or the lower wiring layer.

[Brief explanation of drawings]

FIGS. 1a and 1b are a perspective view and a sectional view of an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Ceramic substrate, 2... Lower conductor layer, 3... Lower insulating layer, 4... Opening, 5...
... Conductor paste, 6 ... Intermediate conductor layer, 7 ... Upper insulating layer, 8 ... Upper conductor layer, 9 ... Notch removal part.

Claims (1)

[Claims] 1. A lower conductor layer provided on an insulator layer or on a substrate whose surface is an insulator, a lower insulating layer formed to cover at least the lower conductor layer, and the lower conductor. an intermediate conductor layer provided on the lower insulating layer and connected to the lower conductor layer through the opening; , in a thick film multilayer wiring board formed by repeating an upper insulating layer provided to cover at least the intermediate insulating layer and an upper conductive layer provided on the upper insulating layer, the lower conductive layer 1. A thick film multilayer wiring board, characterized in that a notch removal portion is provided in a portion of the upper conductor layer located above the opening to which the upper conductor layer and the intermediate conductor layer are connected.