How to use the adhesive sheet

Abstract

The invention discloses a use method for adhesive sheet which belongs to a PCB manufacturing field and comprises the following steps: providing a core plate; preparing at least four copper plates on the core plate; measuring the distances among the copper plates and recording them as initial distances; setting an identical adhesive sheet respectively at the upper side and the lower side of the core plate; and setting a copper foil at the side of the adhesive sheet away from the core plate; performing lamination to the adhesive sheet and the core plate; measuring the distances among the copper plates after the lamination process of the copper foil, the adhesive sheet and the core plate and recording them as the final distances; calculating the difference between the final distances and the initial distances and recording it as the change value; and based on the measured initial distances and the final distances among the copper plates, obtaining the size changing trend of the adhesive sheet so as to infer the influence of the adhesive sheet on the size of the core plate in the PCB manufacturing process.

Description

technical field [0001] The invention relates to the field of PCB production, in particular to a method for using an adhesive sheet. Background technique [0002] Because the adhesive sheet contains resin, it changes from a semi-cured state to a cured state under the action of high temperature and high pressure in the lamination process. There are multiple core boards in a multi-layer PCB. When making a multi-layer PCB, the dimensional change values ​​of the core boards are also different due to the different dimensional changes of the bonding sheets of different glass cloths during the lamination process. If the size of each core board is inconsistent, it will lead to failure modes such as inner layer short circuit and inner layer open circuit due to layer deviation. At present, the way to prevent layer deviation is to make one or more batches of boards first, measure the expansion and contraction values ​​of the core boards of each layer, give a pre-compensation coefficien...

AI Technical Summary

Problems solved by technology

Although this method can solve the scrap caused by layer deviation to a certain extent, it needs to test multiple batches of verification, resulting in low production efficiency and waste of raw materials

At the same time, this method does not consider the influence of the adhesive sheet on the expansion and contraction of the core board size, resulting in the core board being easily affected by the PCB processing process and resulting in layer deviation and scrapping caused by the out-of-tolerance expansion and contraction of the core board size.

Images