Electronic device substrate and its fabrication method, and electronic device and its fabrication method

Abstract

An electronic device substrate is provided with a thin-plate core substrate; a metal electrode provided on the core substrate and electrically connected to an electrode of an electronic component to be packaged thereon; and an electrical insulation layer on which is mounted the electronic component, and which is provided to surround the metal electrode.

Description

[0001] The present application is based on Japanese patent application Nos. 2005-76674 and 2005-290463, the entire contents of which are incorporated herein by reference. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention relates to an electronic device substrate and its fabrication method, and an electronic device and its fabrication method. Particularly, it relates to an electronic device substrate and its fabrication method, and an electronic device and its fabrication method, which is capable of releasing a core substrate from an electronic device substrate side with weak force, reducing the load of chemical or electrochemical dissolution, or mechanical grinding for exposing a terminal surface to a lower surface, and reducing size. [0004] 2. Description of the Related Art [0005]FIGS. 1A and 1B are respectively a front cross-sectional view and a plan view showing an electronic component mount surface of a conventional electronic device. This...

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Benefits of technology

[0074] According to the present invention, in the electronic device substrate and the electronic device, it is possible to reduce device size without applying stress to a package, as the core substrate is released from the electronic device substrate side with

Problems solved by technology

According to the conventional electronic device, in the configuration of FIG. 4, however, there is the problem with very poor adhesion of the gold plating in the functional plating 23 to sealing resin 10.

Specifically, when gold plating is applied to the surface of the functional plating 23, the gold does not form a high electronegativity oxide film, which results in poor adhesion to the sealing resin, and degrades reliability of the electronic device.

However, even this method cannot entirely avoid the following:

To avoid this failure, JP-A-2002-9196 also describes a method thickening the metal of the wiring pattern and fabrication on a periphery an overhanging portion that slightly projects on its sealing resin side, but because the thickness of the wiring pattern is increased, the plating time is long, or the resist film must be removed with a canopy shape held, so that because of these steps, the distance between the adjacent electrodes cannot be reduced, which results in an increase of electronic device dimensions.

For that reason, when this is removed by chemical dissolution or mechanical grinding, the processing time is long because of the thickness, which results in a large load of the chemical dissolution or mechanical grinding for exposing a terminal surface from the package backside.

Also, when the metal base is released by applying mechanical stress, the package is curved or cracked by the stress which is an obstacle particularly in forming a thin electronic device.

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