US Patent 7728232 Printed circuit board assembly having adhesive layer

An exemplary adhesive layer includes an adhesive main body having a first adhesive surface and a second adhesive surface on an opposite side of the adhesive main body to the first adhesive surface. The adhesive main body defines a number of through-holes between the first adhesive surface and the second adhesive surface therein. The through-holes are filled with an inner adhesive that has a higher adhesion than the adhesive main body. Adhesiveness of the first adhesive surface and the second adhesive surface of the adhesive main body can be improved, thereby preventing a printed circuit board having the adhesive layer from distortion.