	US 12,245,411 B2
	Circuit board to which 3D formed electromagnetic shielding film is attached, 3D formable electromagnetic shielding film, and 3D formed electromagnetic shielding film
Chao Yang, Shanghai (CN); Yuan Zhao, Shanghai (CN); Zhiyong Xu, Shanghai (CN); and Ju Le Sun, Shanghai (CN)
Assigned to 3M INNOVATIVE PROPERTIES COMPANY, St. Paul, MN (US)
Appl. No. 18/265,597
Filed by 3M INNOVATIVE PROPERTIES COMPANY, St. Paul, MN (US)
PCT Filed Nov. 23, 2021, PCT No. PCT/IB2021/060881 § 371(c)(1), (2) Date Jun. 6, 2023, PCT Pub. No. WO2022/136973, PCT Pub. Date Jun. 30, 2022.
Claims priority of application No. 202011523926.0 (CN), filed on Dec. 21, 2020.
Prior Publication US 2024/0040760 A1, Feb. 1, 2024
Int. Cl. H05K 9/00 (2006.01); H05K 1/02 (2006.01); H05K 3/24 (2006.01)

CPC H05K 9/0084 (2013.01) [H05K 1/0216 (2013.01); H05K 3/241 (2013.01); H05K 2201/0707 (2013.01)]

4 Claims

1. A circuit board to which a 3D formed electromagnetic shielding film is attached, the circuit board comprising an electronic component, wherein the 3D formed electromagnetic shielding film comprises a molding layer, a shielding layer, and an adhesive film; the molding layer and the adhesive film are laminated; the shielding layer is a conductive non-woven layer embedded in the adhesive film, wherein a ratio of a surface area S2 of the electromagnetic shielding film after forming with an upper surface area of the electronic component deducted to a surface area S₁thereof before forming with the upper surface area of the electronic component deducted is 1.5 to 17, and the electromagnetic shielding film has a surface resistance of less than or equal to 10 Ω and a loss factor value tan δ of less than or equal to 0.2 in the temperature range of 180-250° C.