A method for making L2 blind hole of high-density interconnection circuit board

Abstract

This invention relates to a method for processing second-order blind holes of high density interlinked CB including the following steps: providing a CB with a circuit on one side, forming a first back-glued copper foil on the surface of the circuit, forming multiple first copper windows in the copper foil layer, forming a second back-glue copper foil on the surface of the first copper foil with the first copper windows, utilizing a laser to open multiple second copper windows corresponding to the first ones in the layer of the second copper foil, utilizing a second laser to eliminate the subs of the two copper foils from the second copper windows so as to form multiple second-order blind holes.

Description

technical field [0001] The invention relates to a manufacturing technology of a multilayer circuit board, in particular to a method for manufacturing a second-order blind hole of a high-density interconnection circuit board. Background technique [0002] The expansion of the mobile phone market and the substantial increase in demand have led to the vitality of circuit boards. At present, the circuit boards used in mobile phones generally include traditional laminated boards and build-up multilayer (BUM) according to the process technology. . The BUM board is currently the highest-level process technology for manufacturing mobile phone circuit boards. That is, the outer layer of the double-sided or single-sided board is laminated with Resin Coated Copper Foil (RCC) and formed in a non-mechanical way. Holes (mostly micro-blind holes) become high-density interconnect (HighDensity Interconnect, HDI) circuit boards. HDI circuit boards usually refer to circuit boards that use mi...

AI Technical Summary

Problems solved by technology

[0005] However, in the manufacturing process of the above-mentioned second-order blind holes, both the first copper window and the second copper window are opened by chemical etching, which requires two processes of photoresist coating, exposure, development, and etching. There are many steps in this process, and each Some errors will inevitably be introduced in the steps, so that the position and size of the first copper window and the second copper window obtained will have errors, and the centers of the upper and lower holes of the second-order blind holes obtained in the end will have a large offset, which will affect many The transmission effect of electrical signals between layer lines

In addition, in the chemical etching process, due to the influence of the etching solution, the processed circuit board is prone to expansion and contraction deformation, and the first copper window and the second copper window on the circuit board will also be deformed accordingly, which will affect The shape of the final second-order blind hole will affect the transmission effect of electrical signals between multi-layer lines

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