A Browning Method for Improving Interlayer Cohesion of Printed Circuit Board

Abstract

The invention discloses a browning method for improving the binding force between layers of printed circuit boards, which belongs to the technical field of circuit boards and includes the following steps: S1: Cleaning: soak copper foil in cleaning solution I for 3-5 minutes, then add cleaning Solution II, continue to soak for 3‑5min, then soak in hydrogen peroxide and ethanol for 2‑3min respectively, and then blow dry with nitrogen; S2: Pre-soaking: put the cleaned copper foil in the pre-soaking solution, and ultrasonically vibrate for 3 ‑5min; S3: browning: place the pre-impregnated copper foil in a browning tank with browning solution; S4: wash with water: place the browned copper foil in deionized water, wash it with water, Blow dry with nitrogen. After the browning of the present invention, the sample shows good peeling resistance, and the peeling strength is as high as 0.95 Kg / cm. For the thermal performance test, 6 times of immersion tin, 100 times of cold and heat shock cycles and 6 times of reflow soldering test were carried out on the laminated samples respectively. It was observed that there was no blistering, delamination or bursting phenomenon in the test samples, and the interlayer bonding was strong.

Description

technical field [0001] The invention relates to the technical field of circuit boards, in particular to a browning method for improving the bonding force between layers of printed circuit boards. Background technique [0002] Printed circuit board (PCB) is a collective name for printed circuits and printed components; it is based on the basic material as an insulating board, through wiring, drilling, hole metallization, electroplating, etching, surface treatment and other processes, on the board Form a conductive pattern and often accompanied by various holes (such as metallized holes, component holes, etc.), as a chassis for welding various electronic components (such as inductors, capacitors, resistors) to achieve electrical connection between various electronic components interconnection. In recent years, printed circuit boards have been widely used as one of the important electronic components in electronic equipment, acting as a support for electronic components and pr...

AI Technical Summary

Problems solved by technology

The invention also provides a method for using the copper block black / browning device to black / brown the copper block, through the stirring device, the liquid inlet pipe and the liquid discharge pipe and the black / brown liquid in the black / brown line potion tank The formed circulation loop keeps the components of the blackening / browning liquid in the container effective, and the liquid inlet pipe and the liquid discharge pipe are equipped with automatic valves to control the blackening / browning time. Using this method, the copper block blackening / browning is uniform and the quality is good , which solves the problem of uneven browning of copper blocks in the past, which causes air bubbles in the subsequent process and leads to scrapping, and the interlayer bonding force is low.

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