Patent ID: 7811626

Claim:
A method of manufacturing a printed circuit board, the method comprising: forming a parallelepiped-shaped prepreg having a volume via a reel-based process, wherein the prepreg layer has a thickness of about 0.15 mm, and a first CTE, and wherein the prepreg layer comprises a fiber material and a resin material that, when cured, encapsulates the fiber material, wherein the content of the resin material in the prepreg layer is about no greater than about 70% by volume; forming a circuit pattern on at least one surface of the generally parallelepiped-shaped prepreg; and forming a protection layer only on the circuit pattern, the protection layer having a second CTE, a difference of about 50 ppm is between the first CTE and the second CTE concentrating on the fiber layer bending stresses due to thermal expansion or via hole punching.