Electromagnetic interference shielding on semiconductor devices
A conductive paint electromagnetic interference (EMI) shield for an electronic module or device. The conductive paint is composed of metal particles suspended in a fluidic carrier. In one embodiment, the conductive paint is sprayed onto exterior surfaces of an electronic module or device from a spray gun. The sprayed conductive paint is cured to remove the fluidic carrier, leaving a metal film coated to the outside of the module or device. In one embodiment used with electronic packages in array form, grooves are cut into an encapsulation material of a module so that the shield protection includes sidewalls of the package. In another embodiment used with camera modules, masking is used to selectively shield portions of the module. In a further embodiment, the shield is electrically connected to a ground conductor of a circuit of the electronic module.
1. An electronic module comprising:
a distribution layer having a first surface and side surfaces, the side surfaces being transverse to the first surface;
an integrated electronic circuit attached to the first surface of the distribution layer;
a rigid body enclosing at least a portion of the electronic circuit;
a ground conductor electrically coupled to the electronic circuit, the ground conductor extending from the integrated electronic circuit to one of the side surfaces of the distribution layer, the ground conductor having a coupling surface that is coplanar with the one of the side surfaces of the distribution layer, the ground conductor being positioned within the distribution layer and extending between the integrated electronic circuit and one of the side surfaces;
a plurality of electrical interconnect elements formed in the distribution layer and electrically coupled to the integrated electronic circuit; and
an electrically conductive film adhered to an exterior surface of the rigid body and to the side surfaces of the distribution layer, the film being in contact with the coupling surface of the ground conductor and electrically isolated from a group of the plurality of electrical interconnects.
2. The module of claim 1 wherein the ground conductor lies along an external perimeter edge of the rigid body.
3. The module of claim 1 , the exterior surface of the rigid body comprising a top surface and a sidewall, wherein the top surface and the sidewall meet at an obtuse angle.
4. The module of claim 1 , further comprising a lens enclosed by the rigid body and optically coupled with an image-sensing portion of the electronic circuit.
5. The module of claim 1 wherein the electrically conductive film is composed of at least one of copper, silver, stainless steel, nickel, and nickel coated with copper particles.
6. A package, comprising:
a distribution layer having a first surface, a second surface, and side surfaces, the distribution layer;
a die on the first surface of the distribution layer;
a ground conductor extending from the die to one of the side surfaces of the distribution layer, the ground conductor having a coupling surface that is accessible from the one of the side surfaces;
an encapsulation material on the die and on the first surface of the distribution layer; and
an electrically conductive film formed on the encapsulation material and on the side surfaces of the distribution layer, the film being in contact with the coupling surface of the ground conductor accessible from the one of the side surfaces, the coupling surface of the ground conductor is coplanar with the side surfaces of the distribution layer and the sidewalls of the encapsulation material.
7. The package of claim 6 wherein a contact on the die is coupled to the ground conductor.
8. The package of claim 6 further comprising a plurality of electrical connections formed on the second surface of the distribution layer, one of the electrical connections being coupled to the ground conductor.
9. The package of claim 6 wherein sidewalls of the encapsulation material are coplanar with the side surfaces of the distribution layer.