Circuit board and manufacturing method thereof

Abstract

The invention discloses a circuit board and a manufacturing method thereof. The manufacturing method of the circuit board comprises the following steps: preparing a circuit board to be processed, wherein the circuit board to be processed comprises a plurality of conductive through holes; forming isolation layers on the inner walls of the conductive through holes; performing back drilling processing on each conductive through hole from the first side of the conductive through hole to a first preset position, wherein the distance between the first preset position and the layer, which must be drilled, of the non-drillable layer of the circuit board and is adjacent to the first side is greater than the first preset distance; and etching a part in a first set range on the inner side of the conductive through hole between the first preset position and the non-drillable layer to a second preset position, the distance between the second preset position and one side, adjacent to the first side, of the non-drillable layer of the circuit board being within a second preset range. By means of the scheme, it can be ensured that the insertion loss of the manufactured circuit board is within the preset range.

Description

technical field [0001] The present application relates to the technical field of circuit boards, in particular to a circuit board and a manufacturing method thereof. Background technique [0002] In the production of existing multi-layer circuit boards, it is usually necessary to adopt a back-drilling process to form a back-drilled hole on the basis of the conductive via hole of the multi-layer circuit board, so that the inner layer circuit connected to the back-drilled hole is in the The location of the back-drilled hole is usually used to disconnect the electrical connection, so that the multi-layer conductive layers of the multi-layer circuit board can be formed into a functional circuit. [0003] Existing back drilling generally uses mechanical drilling to expand the conductive vias to remove the conductive medium in the conductive vias. Due to the thickness deviation of the multilayer circuit board in production, it may cause After the back drilling is formed, the heig...

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Problems solved by technology

[0004] The present application provides a circuit board to solve the problem that the back-drilling process in the prior art easily leads to the height of the conductive medium in the conductive via hole between the non-drillable layer and the adjacent must-drillable layer of the multilayer circuit board Exceeding the preset range, resulting in the problem that the insertion loss of the multilayer circuit board is too high

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