Shield sheet for wireless charging module and wireless charging module
A shield sheet comprises a collar magnetic sheet and a center magnetic sheet. The collar magnetic sheet is provided with a hole adapted to the center magnetic sheet. The center magnetic sheet has one end fixed in the hole and the other end protruding out of the collar magnetic sheet. The collar magnetic sheet comprises at least one first magnetic permeable layer, which is a nanocrystal strip, an amorphous strip or a metallic soft magnetic strip. The center magnetic sheet comprises at least two second magnetic permeable layers stacked one on another, which are fragmented nanocrystal strips, fragmented amorphous strips or fragmented metallic soft magnetic strips. Fewer nanocrystal strips are stacked for the collar magnetic sheet in the shield sheet of the invention, facilitating the miniaturization of the shield sheet and increasing charging efficiency.
1. A shield sheet for a wireless charging module, comprising a collar magnetic sheet and a center magnetic sheet, wherein the collar magnetic sheet is provided with a hole adapted to the center magnetic sheet, and the center magnetic sheet has one end fixed in the hole and the other end protruding out of the collar magnetic sheet; the collar magnetic sheet comprises at least one first magnetic permeable layer, which is a nanocrystal strip, an amorphous strip or a metallic soft magnetic strip; and the center magnetic sheet comprises at least two second magnetic permeable layers stacked one on another, which are fragmented nanocrystal strips, fragmented amorphous strips or fragmented metallic soft magnetic strips,
wherein the at least two second magnetic permeable layers of the center magnetic sheet are stacked one on another in a first direction, and the center magnetic sheet is thicker in the first direction than the collar magnetic sheet in the first direction.
2. The shield sheet for the wireless charging module according to claim 1 , wherein the hole is a through hole, and the collar magnetic sheet has a top face coplanar with a top face of the center magnetic sheet.
3. The shield sheet for the wireless charging module according to claim 2 , wherein the top face of the collar magnetic sheet is provided with an adhesive layer, and the top face of the center magnetic sheet is joined with the adhesive layer.
4. The shield sheet for the wireless charging module according to claim 1 , wherein the second magnetic permeable layers have the magnetic permeability of 200-6000; the first magnetic permeable layer is the nanocrystal strip having the magnetic permeability of more than or equal to 5000, the amorphous strip having the magnetic permeability of more than 1000, or the metallic soft magnetic strip having the magnetic permeability of more than or equal to 800.
5. The shield sheet for the wireless charging module according to claim 4 , wherein the collar magnetic sheet is formed by stacking two or three layers of nanocrystal strips.
6. The shield sheet for the wireless charging module according to claim 5 , wherein two adjacent layers of nanocrystal strips in the collar magnetic sheet are bonded with an insulating adhesive.
7. A wireless charging module, comprising a charging coil, wherein the wireless charging module further comprises the shield sheet for the wireless charging module according to claim 1 , and a portion of the center magnetic sheet is located in a hollow area of the charging coil.
8. The wireless charging module according to claim 7 , wherein an inner edge face of the charging coil supports against an outer edge face of the center magnetic sheet.