Effect of Copper Residue Rate in Inner Layer of PCB on Sheet Shrinkage_Shenzhen StarLight Industrial Development Co., Ltd.

Effect of Copper Residue Rate in Inner Layer of PCB on Sheet Shrinkage

source:Other information release time:2022-11-28 Hits: Popular:PCB Assembly company: Share:

　　 Double Sided PCB

　　1、 For the expansion and contraction of core board after PCB etching (compression structure of ordinary four layer PCB board)

　　1. The thickness is 0.1mm, and the etching expansion and contraction of the surface copper thickness Hoz core plate is larger than that of the surface copper thickness 2oz core plate;

　　2. When other conditions are the same, the surface copper Hoz core plate has a large longitudinal expansion and contraction, while the surface copper 2oz core plate has a longitudinal contraction;

　　3. The residual copper rate of circuit board has a significant impact on the surface copper Hoz core board. The lower the residual copper rate, the greater the expansion and contraction, and the more significant the longitudinal change.

　　2、 For the expansion and contraction of the core board after pressing (the pressing structure of the ordinary four layer PCB board)

　　1. When other conditions are the same, the zonal shrinkage of the core plate with the thickness of 2oz on the surface copper is more obvious than that of the core plate with the thickness of Hoz on the surface copper;

　　2. For the core board of the same circuit board model, the longitudinal expansion and contraction are larger than the latitudinal expansion and contraction, and this phenomenon is more obvious with the increase of surface copper thickness;

　　3. When other conditions are the same, the higher the copper residue rate in the inner layer of the circuit board, the better the dimensional stability of the pressing, and the dimensional stability in the latitudinal direction is better than that in the longitudinal direction;

　　4. When other conditions are the same, the higher the copper residue rate in the inner layer of the circuit board, the smaller the compression expansion and contraction of the core board, which tends to be linear, and the warp direction changes more significantly;

　　5. When the residual copper rate of the inner layer of the circuit board is less than 40%, the longitudinal compression shrinkage of the core board with surface copper thickness of 2oz of 0.1mm is greater than that of the core board with surface copper thickness of Hoz, and the reverse is true when the residual copper rate is greater than 40%.

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