1. Technical Field
The subject matter herein generally relates to a field of anti-electromagnetic interference (EMI) shielding.
2. Description of Related Art
Communication devices are required to be small size and high sensitivity for signals. EMI in the small package is an issue to be solved.
Generally, there are several solutions for protecting against external magnetic field on radio frequency (RF) modules: (a) the RF module is mounted on a motherboard, and a metal shielding cover is placed around the RF module; (b) a metal shielding cover is placed on the RF module; (c) conductive material is plated or sprayed onto a surface of the RF module and is grounded; (d) conductive material is plated or sprayed onto a surface of the RF module and is connected to grounding wires outside of the RF module; and (e) conductive material is plated or sprayed onto the top surface of the RF module and is grounded by metal wires, the shielding of the side of the RF module is obtained through the metal wires. However, these solutions still have disadvantages.
Many aspects of the present embodiments can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present embodiments. Moreover, in the drawings, all the views are schematic, and like reference numerals designate corresponding parts throughout the several views.
The disclosure is illustrated by way of example and not by way of limitation in the figures of the accompanying drawings in which like reference numerals indicate the same or similar elements. It should be noted that references to “an” or “one” embodiment in this disclosure are not necessarily to the same embodiment, and such references can mean “at least one.”
In the embodiment, the grounding terminal 5 is positioned on the second surface 9c of the substrate 9 to directly connect to ground. In an alternative embodiment, the grounding terminal 5 may be disposed on any part of the substrate 9 which is without a coated layer. The grounding terminal 5 may be directly connected to ground. In an alternative embodiment, the grounding terminal 5 may be connected to a grounded shell of other electrical equipment. The shielding metal layer 3 may be grounded by either method.
Referring to
To simplify the structure and processing of the shielding package, the conductor is a part of the shielding metal layer 3 inside the notch 2a. Taking the flip chip 1 as an example, and referring to
In the embodiment of the shielding package, the defining of a conductive through hole inside the component and substrate to make the shielding metal layer 3 grounded achieves effective EMI shielding. There is no requirement of peripheral shielding device and peripheral shielding wires, the shielding package not only simplifies the structure, but also decreases its size.
As shown in
First, a substrate 9 is manufactured, and at least one grounding terminal 5 is positioned on the outer side of the substrate 9. A first through hole is defined in the substrate 9, and the first through hole 9a is created opposite to the grounding terminal 5. A conductive film is coated on the inner wall of the first through hole 9a, and the conductive film is electrically connected to the grounding terminal 5.
At least one component is mounted on the substrate 9 and a second through hole 1a is defined in the substrate 9. A conductive film is coated on the inner wall of the second through hole 1a, and the conductive film of the second through hole 1a is electrically connected to the conductive film of the first through hole 9a.
The component is encapsulated in a glue-injection layer 2, the glue-injection layer 2 infilling the gap between the component and the substrate 9. Thus, all parts are packaged on the substrate 9.
A notch 2a is formed, positioned on the glue-injection layer 2, and the glue-injection layer 2 is connected to the second through hole 1a.
A shielding metal layer 3 is formed on an outer surface of the glue-injection layer 2, the shielding metal layer 3 fills up the notch 2a, and the shielding metal layer 3 is electrically connected to the conductive film of the second through hole 1a. Specifically, the shielding metal layer 3 can be formed by sputtering copper materials on the surface of glue-injection layer. In an alternative embodiment, the shielding metal layer 3 can be made of high-permeability glue and have high conductivity using one of iron, cobalt, nickel, in an alloy with glue.
In order to improve the processing efficiency of manufacturing the substrate 9, the substrate 9 can be divided into multiple substrate units according to predetermined specifications. The grounding terminal 5, the first through hole 9a and the conductive film of the inner wall of the first through hole 9a are formed on the substrate units. In addition, after forming the shielding metal layer 3, the substrate 9 is cut into shielding package units. Advantages are that in the step of forming the shielding metal layer 3, splash plating the entire substrate may greatly save material cost compared to splash plating each of the the substrate units. In addition, there is no metal splash plated on the sidewall of the cut shielding packaging unit, avoiding the issue of short circuits when the shielding packaging is installed on a circuit board.
Although the features and elements of the present disclosure are described as embodiments in particular combinations, each feature or element can be used alone or in other various combinations within the principles of the present disclosure to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.
Number | Date | Country | Kind |
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201510869794.X | Nov 2015 | CN | national |