Flexible circuit board via hole forming method

Abstract

The invention provides a flexible circuit board via hole forming method. With the flexible circuit board via hole forming method of the invention adopted, the connection of solid via holes between conductor layers of an integrated circuit package substrate can be realized. Compared with a method according to which cut-through hollow via holes formed by a traditional mechanical hole forming technology are connected, the flexible circuit board via hole forming method enables less area occupation, upper and lower corresponding line rackets of the holes are integrally preserved and are not damaged by the via holes, and therefore, corresponding electrical properties are excellent, and high reliability can be realized, and lead bonding operation can be directly operated on the via holes. With the flexible circuit board via hole forming method of the invention, a production process is simplified, production cost is saved, processing efficiency is improved, and a guarantee is provided for subsequent production of a high-precision image.

Description

technical field [0001] The invention belongs to the technical field of PCB processing, and in particular relates to a method for forming a through hole of a flexible circuit board. Background technique [0002] With the development of integrated circuits, the requirements for integrated circuit packaging have also increased, and the requirements for printed circuit boards used in packaging are also developing towards higher wiring density, better electrical performance and thermal performance. In order to meet the above requirements, the development of high-reliability via hole technology is the key, which has a great impact on the density of wiring and the electrical and thermal performance after packaging. [0003] As we all know, there must be several via holes on the printed circuit board to connect the circuits on the upper and lower adjacent conductive surfaces of the insulating medium layer. The via holes in the prior art will have a great negative impact on the subs...

AI Technical Summary

Problems solved by technology

The via holes in the prior art will have a great negative impact on the subsequent process flow. For example, in the transfer process of the circuit pattern after the hollow copper via is formed, the unevenness of the substrate surface caused by the hollow via hole will cause photosensitive resistance. Poor adhesion of the etch film can easily cause line defects

In addition, this kind of through hole will have a great influence on the wiring design, so that the hole layout on the racket is limited, so that special wiring structures such as stacked holes cannot be realized, thus restricting the improvement of wiring density