Wireless electronic device with magnetic shielding layer
An electronic device may have a housing, electrical components, and other electronic device structures. A display may be mounted in the housing. The display may have a transparent display cover layer and a display layer such as an organic light-emitting diode display layer that is mounted to the underside of the transparent display cover layer. A flexible printed circuit with metal traces may be mounted under the organic light-emitting diode display layer. The metal traces may form coils for a near-field communications inductive loop antenna. A magnetic shielding layer may be interposed between the housing and the flexible printed circuit. The magnetic shielding layer may include a polymer magnetic shielding layer having magnetic material particles embedded in a polymer matrix. The magnetic shielding layer may also have a polymer-binder-free magnetic shielding layer.
1. An electronic device, comprising:
a housing;
a display mounted in the housing, wherein the display includes a transparent display cover layer and a display layer mounted under the transparent display cover layer;
an antenna layer including metal traces that form an antenna; and
a magnetic shielding layer adjacent to the antenna layer, wherein the antenna layer is interposed between the magnetic shielding layer and the display, the magnetic shielding layer includes a polymer magnetic shielding layer having particles of magnetic material embedded in a polymer binder, the magnetic shielding layer includes a polymer-binder-free magnetic shielding layer having a layer of magnetic material, and the polymer magnetic shielding layer is interposed between the polymer-binder-free magnetic shielding layer and the antenna layer.
2. The electronic device defined in claim 1 wherein the display layer comprises an organic light-emitting display layer.
3. The electronic device defined in claim 1 wherein the antenna layer comprises a flexible printed circuit, the antenna comprises a near-field-communications loop antenna, and the metal traces form coils for the antenna.
4. The electronic device defined in claim 1 wherein the polymer magnetic shielding layer includes a protrusion.
5. The electronic device defined in claim 4 further comprising a structure with a surface, wherein the protrusion contacts the surface.
6. The electronic device defined in claim 1 wherein the metal traces form coils in a near-field communications inductive loop antenna.
7. The electronic device defined in claim 6 wherein the layer of magnetic material of the polymer-binder-free magnetic shielding layer is formed on a plastic liner and the layer of magnetic material is interposed between the plastic liner and the polymer magnetic shielding layer.
8. The electronic device defined in claim 7 wherein the antenna layer comprises a flexible printed circuit.
9. The electronic device defined in claim 8 wherein the display layer comprises an organic light-emitting diode display layer and the particles of magnetic material comprise ferrite particles.
10. An electronic device, comprising:
a housing;
a display mounted in the housing, wherein the display includes a transparent display cover layer and an organic light-emitting diode display layer mounted under the transparent display cover layer;
a flexible printed circuit containing coiled metal traces that form a near-field communications inductive loop antenna; and
a magnetic shielding layer, wherein the flexible printed circuit is interposed between the magnetic shielding layer and the organic light-emitting diode display layer, the magnetic shielding layer includes a polymer-binder-free magnetic shielding layer and a polymer magnetic shielding layer, the polymer magnetic shielding layer includes particles of magnetic material embedded in a polymer matrix, the polymer-binder-free magnetic shielding layer includes a layer of magnetic material, the polymer-binder-free magnetic shielding layer is formed separately from the polymer magnetic shielding layer, and the polymer magnetic shielding layer is interposed between the polymer-binder-free magnetic shielding layer and the flexible printed circuit.
11. The electronic device defined in claim 1 , further comprising:
a housing wall with an interior surface and an exterior surface, wherein the exterior surface of the housing wall forms an exterior surface for the electronic device and the polymer magnetic shielding layer includes a protrusion that directly contacts the housing wall and forms a seal with the housing wall.
12. The electronic device defined in claim 1 , wherein the polymer-binder free magnetic shielding layer is formed separately from the polymer magnetic shielding layer.
13. The electronic device defined in claim 12 , wherein the polymer magnetic shielding layer is smoother than the polymer-binder free magnetic shielding layer.
14. The electronic device defined in claim 1 , wherein the display layer comprises a display layer selected from the group consisting of: a liquid crystal display layer, an organic light-emitting diode display layer, a plasma display layer, an electrophoretic display layer, and an electrowetting display layer.
15. The electronic device defined in claim 1 , wherein the polymer-binder-free magnetic shielding layer is a sintered ferrite layer.
16. The electronic device defined in claim 10 , wherein the polymer-binder-free magnetic shielding layer is a sintered ferrite layer.