A method for improving ion migration of pcb board

Abstract

The invention relates to a method for improving ionic migration of a PCB. The method comprises steps of: (1) drilling the PCB and baking the PCB for a while in order to melt and retract resin in the PCB, increase the compactness of resin on the hole walls in the PCB, and decrease holes in glass fiber bundles in the PCB, wherein the baking temperature is greater than the TG value of the PCB; (2) removing resin smears in the PCB by using a plasma physics de-smearing method after the PCB is baked, namely placing the PCB in vacuum chamber, applying a certain amount of nitrogen N2, oxygen O2, carbon tetrafluoride CF4, and hydrogen H2 to the vacuum chamber and applying positive and negative charges to the vacuum chamber by a power device in order to ionize gases in the vacuum chamber and further form plasma in the form of a mixture for removing the resin smears in the PCB; and (3) directly initiating a copper plating process after the resin smears are removed. The method may decrease holes in the glass fiber bundles in the PCB and reduces adverse channels on the tail ends of glass fibers so as to improve the ionic migration of the PCB.

Description

technical field [0001] The invention belongs to the technical field of manufacturing printed circuit boards (PCB boards for short), and in particular relates to a method for improving ion migration of PCB boards. Background technique [0002] In the field of electronic equipment, take automotive electronics or some military equipment as an example, the requirements for high temperature and high humidity environment are getting higher and higher. With the development of such products towards high density, the hole spacing is getting smaller and smaller, which makes Printed circuit boards (referred to as PCB boards) have correspondingly increased reliability requirements for holes. When the PCB board / PCBA board is working in a high temperature and high humidity environment, there may be serious conductive anode filaments growing along the resin or glass fiber interface between the two insulated conductors (commonly known as ion migration, full name: ConductiveAnodic Filament, ...

AI Technical Summary

Problems solved by technology

[0004] 1. Due to the high-speed rotation of the PCB board during drilling, the temperature in the hole is too high and the resin in the board is melted, and there will be holes in the glass fiber bundles

[0005] 2. The existing desmear process adopts the conventional desmear desmear method. The copper penetration of the glass fiber yarn caused by this method will reach at least 25-50um, and the IPC-6012 standard is less than 100um, which cannot meet the development of high-density PCB boards. Require

[0006] 3. Desmear desmearing belongs to chemical method. The desmear desmearing process uses highly corrosive potion, the cost of environmental protection treatment is high, and the human body will be harmed after contact.

Images