Embedded magnetic component
In manufacturing an embedded magnetic component, a cavity is formed in an insulating substrate with one or more channels connecting the cavity to an exterior of the component. The channels include one or more obstruction sections that define a sealed base area of the cavity into which adhesive is dispensed to secure the magnetic core in the cavity. The obstruction sections prevent egress of the adhesive before it hardens. The cavity and the magnetic core are then covered with a first insulating layer. Through holes are formed through the first insulating layer and the insulating substrate, and plated up to form conductive vias. Metallic traces are added to the exterior surfaces of the first insulating layer and the insulating substrate to form upper and lower winding layers. The metallic traces and the conductive vias form the windings for an embedded magnetic component, such as a transformer or an inductor.
1. An embedded magnetic component comprising:
a base insulating substrate including first and second sides opposing one another;
a cavity in the base insulating substrate, the cavity including a cavity floor and side walls connected by the cavity floor;
a channel connecting the cavity to an exterior of the base insulating substrate, the channel including a channel floor connecting to the cavity floor, and channel side walls connected by the channel floor;
a magnetic core located in the cavity;
an insulating layer located on the base insulating substrate and covering the magnetic core and the cavity to define an insulated substrate;
one or more electrical windings, passing through at least the insulated substrate and the insulating layer and disposed around the magnetic core;
a layer of adhesive on the cavity floor such that the magnetic core is secured in the cavity by the layer of adhesive on the cavity floor; and
at least one channel obstruction portion at least partially blocking egress of the adhesive layer to an outside of the component from the cavity; wherein
the at least one channel obstruction portion includes an obstruction projection that is raised in comparison to the channel floor and that extends between the channel side walls such that each end of the obstruction projection is in direct contact with the channel side wall.
2. The component of claim 1 , wherein the at least one channel obstruction portion is located at an end of the channel remote from the cavity, adjacent the exterior of the substrate.
3. The component of claim 1 , wherein the channel floor is raised in comparison to the cavity floor and the channel floor defines the at least one channel obstruction portion.
4. The component of claim 1 , further comprising at least one air gap between the magnetic core and the cavity and/or the insulating layer.
5. The component of claim 1 , wherein the cavity and the magnetic core are toroidal.
6. The component of claim 4 , wherein the at least one air gap is located between the magnetic core and the cavity side walls, and the at least one air gap is located between the magnetic core and the insulating layer, and is free of adhesive.
7. The component of claim 1 , wherein the electrical windings include isolated primary and secondary electrical windings, passing through at least the insulated substrate and the insulating layer and disposed around first and second sections of the magnetic core.