ANTI-EMI SHIELDING PACKAGE AND METHOD OF MAKING SAME

An anti-EMI shielding package includes a substrate, a component disposed on the substrate, a glue-injection layer, and a shielding metal layer covering the outer surface of the glue-injection layer. A grounding terminal is positioned on an outer side of the substrate. The substrate defines a first through hole, the component defines a second through hole, and a conductive layer is coated on the inner wall of the first through hole and the second through hole. The shielding metal layer, the conductive layer of the second through hole, the conductive layer of the first through hole, and the grounding terminal are connected and form a conductive loop, the shielding metal layer being grounded. A method of making same provides a simple and reliable shielding package formed with less material and low cost.

BACKGROUND

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.

DETAILED DESCRIPTION

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.”

FIG. 1shows a shielding package. The shielding package comprises a substrate9, the substrate9has a first surface9band a second surface9cparallel to the first surface9b.Referring toFIG. 2, at least one component is disposed on the substrate9. The component may be an exposed chip8adhesively bonded to the substrate9, the component may be an exposed chip8flipped and soldered in the substrate9to form a flip chip1, the component also can be a passive device6assembled on the substrate9. And the component is disposed on the first surface9bof the substrate9. Referring toFIG. 3and FIG.4, the shielding package further comprises a glue-injection layer2covering the component and filling the gap between the component and the substrate9. Referring toFIG. 5, a shielding metal layer3covers the outer surface of the glue-injection layer2. A grounding terminal5is positioned on the outer side of the second surface9c.The substrate9defines a first through hole9acorresponding to the location of the grounding terminal5. The first through hole9apasses from the first surface9bto the second surface9c.At least one component defines a second through hole1a.A conductive layer is coated on the inner wall of the first through hole9aand the second through hole1a.The glue-injection layer2defines a notch2a(as shown inFIG. 4). A conductor inside the notch2acan communicate with the shielding metal layer3and the conductive layer of the second through hole1a.The shielding metal layer3, the conductive layer of the second through hole1a,the conductive layer of the first through hole9a,and the grounding terminal5are connected in sequence to form a conductive loop, and the shielding metal layer3is grounded.

In the embodiment, the grounding terminal5is positioned on the second surface9cof the substrate9to directly connect to ground. In an alternative embodiment, the grounding terminal5may be disposed on any part of the substrate9which is without a coated layer. The grounding terminal5may be directly connected to ground. In an alternative embodiment, the grounding terminal5may be connected to a grounded shell of other electrical equipment. The shielding metal layer3may be grounded by either method.

Referring toFIG. 5, when the component is an exposed chip8, the exposed chip8is flipped and soldered in the substrate9to form a flip chip1. Specifically, the exposed chip8is mounted and connected to the substrate9through a plurality of conductive copper columns10and flip bonding pins1c.Thus the conductive layer of the first through hole9a,the conductive layer of the second through hole1a,and the flip bonding pin1care conductively connected through the conductive copper column10, and a pathway as a conductive loop is formed by connecting the shielding metal layer3, the conductor inside the notch2a(as shown inFIG. 4), the conductive layer of the second through hole1a,the conductive layer of the first through hole9a,the conductive copper column10, the flip bonding pin1c,and the grounding terminal5. The shielding metal layer3must also be grounded. When the component is an exposed chip8, the exposed chip8may be adhesively bonded to the substrate9and electricity connected to the substrate by a bonding wire7. The component also can be a passive device6or surface mounted packaged chip assembled on the substrate.

To simplify the structure and processing of the shielding package, the conductor is a part of the shielding metal layer3inside the notch2a.Taking the flip chip1as an example, and referring toFIG. 6, the flip chip1includes a chip body lb. Conductive copper columns10are disposed on one surface of the flip chip1, bonding pins1care positioned on the front end of the conductive copper column10, and the flip chip1is flipped and soldered on the substrate9by the bonding pins1c.There is a chip metal layer4on the other surface of the flip chip1, the chip body1bdefines a second through hole1aconnected to the chip metal layer4, and conductive layer is coated in the inner wall of the second through hole1a.The flip chip1is mounted on the substrate9and packaged by glue-injection layer2(as shown inFIG. 5). The glue-injection layer defines a notch2aconnected to the chip metal layer4, therefore, the shielding metal layer3is infilled into the notch2aat the same time as a shielding metal layer3is formed on the surface of the glue-injection layer2. The shielding metal layer3and the chip metal layer4of the flip chip1are thus electrically connected, and a conductive loop is formed by connecting with the shielding metal layer3, the chip metal layer4of the flip chip1, the conductive layer of the second through hole la, the conductive copper column10, the flip bonding pin1c,the conductive layer of the first through hole9a,and the grounding terminal5. The shielding metal layer3being grounded protects the flip chip1packaged on the substrate9from electromagnetic interference. It is understood that other components such as exposed chip, passive device, chip package can also be shielded between the substrate9and the shielding metal layer3.

In the embodiment of the shielding package, the defining of a conductive through hole inside the component and substrate to make the shielding metal layer3grounded 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 inFIG. 1toFIG. 6, a method for manufacturing an anti-electromagnetic interference (EMI) shielding package comprises the following steps.

First, a substrate9is manufactured, and at least one grounding terminal5is positioned on the outer side of the substrate9. A first through hole is defined in the substrate9, and the first through hole9ais created opposite to the grounding terminal5. A conductive film is coated on the inner wall of the first through hole9a,and the conductive film is electrically connected to the grounding terminal5.

At least one component is mounted on the substrate9and a second through hole1ais defined in the substrate9. A conductive film is coated on the inner wall of the second through hole1a,and the conductive film of the second through hole1ais electrically connected to the conductive film of the first through hole9a.

The component is encapsulated in a glue-injection layer2, the glue-injection layer2infilling the gap between the component and the substrate9. Thus, all parts are packaged on the substrate9.

A notch2ais formed, positioned on the glue-injection layer2, and the glue-injection layer2is connected to the second through hole1a.

A shielding metal layer3is formed on an outer surface of the glue-injection layer2, the shielding metal layer3fills up the notch2a,and the shielding metal layer3is electrically connected to the conductive film of the second through hole1a.Specifically, the shielding metal layer3can be formed by sputtering copper materials on the surface of glue-injection layer. In an alternative embodiment, the shielding metal layer3can 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 substrate9, the substrate9can be divided into multiple substrate units according to predetermined specifications. The grounding terminal5, the first through hole9aand the conductive film of the inner wall of the first through hole9aare formed on the substrate units. In addition, after forming the shielding metal layer3, the substrate9is cut into shielding package units. Advantages are that in the step of forming the shielding metal layer3, 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.