A manufacturing process of high-density circuit board

Abstract

The invention discloses a manufacturing technology of a high density circuit board and belongs to the integrated circuit field. A manufacturing technology of the high density circuit board adopts a general RCC base material. Through a thinning copper technology, an ultrathin copper layer is acquired. Through a laminated mode, the RCC base material after the thinning copper is pressed with a manufactured circuit board. Then through the thinning copper technology, the ultrathin copper layer is acquired. A through hole or a blind hole is formed through a UV-laser form. A dry film is sticked, an image is transferred and a coating corrosion resistance layer is formed. Graph electrocoppering is performed so as to form a line and a filling hole. The film is removed. Difference etching is performed to remove base copper so as to obtain a conductive line. By using the technology of the invention, overall thickness of a substrate is reduced; wiring density is increased and complete RRC performance of a high frequency signal during transmission is improved.

Description

technical field [0001] The invention relates to a manufacturing process of a high-density circuit board, which belongs to the field of integrated circuits. Background technique [0002] At present, electronic products are developing towards the trend of lightness, thinness and miniaturization. The volume of IC is getting smaller and stronger, the number of pins is increasing, and the signal transmission speed is getting faster and faster. The above performance must be required: IC packaging circuit The board has an ultra-high wiring density, and the interlayer connection is transformed from a hollow via hole to a solid blind hole filling type. [0003] At present, the mainstream process of multilayer high-density packaging circuit boards is the semi-additive method. specifically is: The outer layer mainly adopts RF4 substrate or Ajinomoto's patented product ABF substrate. FR4 or ABF substrate can be metallized by electroless copper plating on the surface to produce ultra...

AI Technical Summary

Problems solved by technology

[0004] The shortcomings of the traditional process are: (1) Electroless copper plating on the RF4 or ABF substrate to construct the conductive layer, and then pattern copper plating to form the circuit

The bonding force between the chemical copper layer and the RF4 or ABF base material is generally weak, and it needs to be soldered at 230~260°C during the subsequent component mounting. Under the action of this thermal shock, the copper layer and the RF4 or ABF base material may occur Separation reduces the reliability of the product; (2) In order to realize the filling connection of solid blind holes between layers, the traditional process adopts the form of electroplating copper on the board surface, which will inevitably lead to a thicker copper layer on the board surface, and the smaller the hole diameter, the thicker the surface copper. When the bottom copper is removed by the final differential etching, the undercut is too large, which makes it difficult to form lines

(3) The minimum thickness of multi-layer high-density packaging circuit boards manufactured with RF4 or ABF substrates is not less than 200 μm, which is not conducive to obtaining ultra-thin packaging substrates

[0006] The disadvantages of this process are: (1) The dielectric layer is laminated to the prepared circuit board first, and then thinned. Since the prepared circuit board has formed a conductive line, a "conformal effect" occurs during the lamination process. The formed conductive line pattern is transmitted to the conductive layer on the medium, resulting in unevenness of the conductive layer on the medium layer, and uneven thickness of the conductive layer after thinning treatment, which eventually causes differential etching to remove the conductive bottom layer. The conductive bottom layer is uneven, causing poor open and short circuit of the line

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