Fabrication method of circuit board with back-drilled resin-stuffed holes

Abstract

The invention discloses a fabrication method of a circuit board with back-drilled resin-stuffed holes. The method comprises the following steps: drilling through to-be-back-drilled holes and other all through holes on a laminated circuit board which is subjected to front procedure treatment; carrying out copper precipitation conduction on all holes; carrying out the steps of full-plate copper plating, pattern plating, full-plate tinning and the like; electrically testing the back-drilled holes; pasting a dry film on a copper foil surface of the laminated circuit board for sealing the holes; exposing and developing the back-drilled holes requiring resin stuffing; stuffing the back-drilled holes with resin and grinding the resin smooth; taking off the dry film for sealing the holes; and carrying out subsequent procedures of outer circuit pattern transferring and the like. According to the fabrication method disclosed by the invention, selective stuffing of the back-drilled holes can be achieved by sealing the holes with the dry film; the overall process only comprises a one-step through hole drilling process, a one-step copper-deposited plate plating process, a one-step pattern plating process and one-step back-drilling process; the process is simplified; forward and backward transportation between plate-making processes is reduced; and the quality risk in process transportation and plate loading and unloading processes is reduced. An ET test is added before the hole stuffing step, and whether leaking back-drilling and poor back-drilling exist or not is detected, so that the quality is ensured.

Description

【Technical field】 [0001] The invention relates to a method for manufacturing a circuit board with back-drilled resin plug holes, and belongs to the technical field of circuit board production. 【Background technique】 [0002] The copper part of the plated through hole on the circuit board will cause the signal to fold back and resonate, resulting in reflection, scattering, delay, etc. of signal transmission, which will bring distortion to the signal. Using back drilling technology to remove this part of hole copper can improve the signal of electronic products Transmission high frequency, high speed performance. The over-electricity back-drilled holes are exposed to air for a long time and are easy to oxidize. During the packaging process, solder paste may flow into it and affect signal transmission. Therefore, the customer put forward the technical requirements for back-drilled plug holes and then flattening. [0003] The current production method is: pre-order processing -...

AI Technical Summary

Problems solved by technology

The current production method of back-drilling plug hole circuit boards requires secondary drilling of through-holes, primary back-drilling, secondary copper sinking, and secondary graphic electroplating. The existing technology is only applicable to the situation that all back drilling needs to be plugged, not applicable when the design has some back drilling fortresses and some are not plugged, otherwise the process will be more cumbersome and require 2 back drilling or other additional processes