Prevent warpage of multilayer PCB boards during processing

1.Prevent the substrate from being warped due to improper inventory

(1)Due to the increase in warpage of the copper clad laminate during storage, the moisture absorption area of the single-sided copper clad laminate is large. If the inventory environment humidity is high, the single-sided copper clad laminate will significantly increase the warpage. The moisture of the double-sided copper clad plate can only penetrate from the end face of the product, the moisture absorption area is small, and the warpage changes slowly. Therefore, for the copper clad laminate without moisture-proof packaging, pay attention to the warehouse conditions, minimize the humidity of the warehouse and avoid the bare copper clad plate to avoid the warpage of the copper clad laminate during storage.

(2)Improper placement of copper clad laminates will increase warpage. If the vertical or copper clad plate is pressed with heavy objects, poor placement, etc. will increase the copper plate warpage deformation.

2.Avoid warpage caused by improper design of printed circuit board or improper processing.

For example, the PCB conductive circuit pattern is unbalanced or the PCB board is obviously asymmetrical on both sides. On one side, there is a large area of copper foil, which forms a large stress, which causes the PCB board to warp. The processing temperature is high or large thermal shock in the PCB process will cause the PCB to warp. For the impact of improper boarding stocks, the PCB factory is better able to solve the problem, improve the storage environment and eliminate vertical and avoid heavy pressure. For PCB boards with a large area of copper, it is best to mesh the copper foil to reduce stress.