Method of fabricating a substrate having conductive through holes

Abstract

A method of fabricating a substrate having a plurality of conductive through holes is disclosed. Release films are formed on opposite sides of a substrate, and a plurality of through holes penetrating the release films and the substrate are formed. A first metal layer is formed on the release films and the sidewall of each of the through holes prior to removing the release films and the first metal layer thereon. A second metal layer is formed on the first metal layer on the sidewalls of the through holes by electroless plating. Compared to the prior art, the method is simpler and cheaper to carry out while the conductive through holes and a surface circuit layer thereof are fabricated separately, thereby avoiding disadvantage of forming a circuit layer on the surface of the substrate too thick.

Description

technical field [0001] The invention relates to a method for manufacturing a substrate, in particular to a method for manufacturing a substrate with conductive through holes. Background technique [0002] With the rapid development of science and technology, electronic products have become inseparable from our lives, and general electronic products usually include a substrate, and build-up circuits are formed on the opposite surfaces of the substrate, and are electrically connected to it. electronic components. [0003] Based on the above, in order to make full use of the surface area of ​​the substrate and shorten the transmission distance of electronic signals, through holes are generally formed in the substrate through both surfaces, and conductive materials are filled in the through holes to form conductive through holes to electrically connect the substrate. Circuits and electronic components on both surfaces. [0004] see figure 1 , which is a cross-sectional view o...

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Problems solved by technology

[0007] However, the above method of electroplating and hole filling mainly uses the process of electroplating copper to fill the through hole from the side wall to the center. The overall process is complicated and it is not easy to completely fill the through hole; At the same time, it is deposited in the through hole and the surface of the substrate. In order to make the through hole fully filled with copper metal, the time of the copper electroplating process must be increased. At the same time, the copper layer on the surface of the substrate is also thickened due to the long-term copper electroplating process. As a result, the copper layer on the surface of the substrate is too thick, making the overall thickness of the substrate exceed the customer's specification; in addition, the surface of the substrate at the through hole is also prone to form cavities due to electroplating and filling holes, and the overall process time is longer, which also affects the production capacity of the substrate. and cost

[0008] Therefore, how to solve the above-mentioned problems in the prior art about the complicated and time-consuming process of forming conductive vias in the substrate, the poor quality of the conductive vias, and the excessive thickness of the copper layer on the surface of the substrate, so as to increase the production capacity of the substrate and reduce the cost , has become an urgent problem to be solved

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