Method for fabricating conductive structures of substrate

Abstract

A method for fabricating a conductive structure of a substrate includes the steps of: providing an insulating substrate having opposite first and second surfaces and forming an insulating adhesive film on the second surface of the insulating substrate; forming at least a through hole penetrating the insulating substrate and the insulating adhesive film and forming a conductive foil on the insulating adhesive film so as to cover the through hole; and forming a shielding material on the conductive foil and the second surface of the insulating substrate and performing an electrochemical deposition process through the conductive foil so as to fill the through hole with a conductive material along a direction towards the first surface of the insulating substrate, thereby preventing the formation of voids in the through hole and hence reducing the overall resistance and preventing a blister effect from occurring.

Description

technical field [0001] The invention relates to a conduction process method of a substrate, in particular to a conduction process method of filling conductive material into a through hole of the substrate. Background technique [0002] To form a conductive structure in the through hole of the substrate, the electroplating hole filling technology is usually used. As shown in the Taiwan Patent No. 540279, a through hole is formed on the substrate first, and a conductive structure is formed on the entire surface of the substrate by sputtering. Then, the electroplating process is carried out on the through holes and the surface of the substrate, and the dry film is pasted to carry out the lithography process. Then, the conductive material is filled in the through holes by the electroplating step, and the electroplating step is simultaneously formed on the surface of the substrate. The required metal circuit layer, and finally, the steps of film removal, etching, and packaging ar...

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Problems solved by technology

[0003] However, these existing electroplating hole filling technologies are mainly to fill the through hole with conductive material from the side wall of the through hole to the center of the through hole, and it is not easy to completely fill the through hole. Therefore, the through hole Conductive materials will have a certain number of pores, and these pores will increase the overall resistance value and reduce the transmission efficiency of electrical signals

What's more, in a high temperature environment, the air in the pores will expand, resulting in serious defects such as blast holes

[0004] In addition, in the currently implemented electroplating process, conductive materials are also deposited simultaneously on the surface of the substrate and the surrounding parts of the through holes to form a metal circuit layer. However, in order to minimize the generation of the aforementioned pores, the metal circuit on the surface The layer is often too thick, making the overall thickness of the product exceed the predetermined specification, thus also increasing the thermal resistance in the direction perpendicular to the substrate

[0005] In addition, the metal circuit layer on the surface of the substrate also has the defect of insufficient flatness. The substrate surface will have cavities in the metal circuit layer at or near the through holes, and the cavities will become obstacles to the subsequent die-bonding process.

The current solution is to avoid cavities for die bonding, but this solution also reduces the effective area utilization of the substrate surface, which also affects production capacity and cost

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