PCB Warpage Prevention


 

1.engineering design:

Interlayer prepreg alignment should correspond;

Laminated core boards and prepregs should use the same supplier product;

The copper area of the outer C/S surface is as close as possible, and an independent grid can be used;


2. before baking the material

Generally 150 degrees 6 to 10 hours, the exclusion of water vapor inside the board, further curing the resin completely, eliminating the stress within the board; baking the board before the material is opened, regardless of the inner layer or both sides are needed!


3. multilayer laminate laminating pressure plate should pay attention to the latitude and longitude direction:

The ratio of warp and weft shrinkage is not the same. Before prepreg stacking, attention should be paid to the direction of warp and weft. When the core board is blanked, attention should also be paid to the latitude and longitude direction; the direction of warpage of the general plate is the warp direction; the long direction of the copper plate is the warp direction;


In addition to the above warpage note PCB guest board also has the following:

1. laminated thickness to eliminate stress After the pressure plate, cold trim, trim flash;

2. Bake plate before drilling: 150 degrees for 4 hours;

3., the best plate is not mechanically brushed, using chemical cleaning; plating using a special fixture to prevent the plate bending

4.after spraying tin on the flat steel plate naturally cooled to room temperature or air-bed cooling after cleaning;

5.warping plate processing: 150 degrees or hot pressure 3 to 6 hours, using a smooth and smooth steel plate weight, 2-3 times baking


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