Magnetic field shielding packaging structure

Abstract

The utility model provides a magnetic field shielding packaging structure, comprising a packaging frame provided with packaging pins; the interposer is arranged on the packaging frame, the interposer is provided with an inner side electrode and an outer side electrode, the inner side electrode and the outer side electrode are arranged at an interval, and the inner side electrode and the outer side electrode are electrically connected through a metal wire arranged in the interposer; the outer side electrode is electrically connected with the packaging pin; a shielding pad disposed on the interposer, the shielding pad having a first through hole corresponding to the inner electrode; the chip is arranged on the shielding gasket, and an electrode of the chip is electrically connected with the inner side electrode through the first through hole; and the bottom of the magnetic shielding cover is provided with a concave accommodating space, the concave accommodating space is used for accommodating the chip, the edge of the bottom of the magnetic shielding cover is in contact with the shielding gasket, and the edge of the magnetic shielding cover is arranged at the interval position of the inner side electrode and the outer side electrode. According to the utility model, the process difficulty of magnetic field shielding packaging can be effectively reduced on the premise of ensuring the shielding effect.

Description

Technical Field

[0001] The utility model relates to the technical field of chip packaging, in particular to a magnetic field shielding packaging structure. Background Art

[0002] Magnetic shielding is a key issue in the application of magnetic random access memory (MRAM). Adding a magnetic shielding structure to a packaged chip is a commonly used solution. Generally, a magnetic shielding material is used to surround the chip to obtain a high magnetic shielding efficiency. However, the chip needs to be electrically connected to external pins through wire bonding or other means. How to ensure electrical connection while surrounding the chip is the core difficulty of magnetic shielding packaging. Currently, the solutions for magnetic shielding structures include the following: 1. To pursue magnetic shielding efficiency, the magnetic shielding structure is very complex, and the packaging operability is low; 2. To pursue packaging operability, the magnetic shielding structure is simplified, resulting in low magnetic shielding efficiency; 3. The magnetic shielding efficiency and packaging operability are both good, but it is only applicable to packaging forms with simple bonding situations, such as SOP packaging.

[0003] For a chip using wire bonding, to ensure that the wire is not affected by the magnetic shielding structure, generally, there are the following ideas: a) Open holes in the side wall or top of the magnetic shielding structure, and the wire passes through the holes; due to the large number of wires, this idea usually leads to a complex side wall structure, poor processability, and high cost; b) Only two side walls of the magnetic shielding structure are retained, and the other two directions do not have side walls for wire bonding. This solution can be better used for packaging forms with wire bonding on two sides, such as SOP, etc., but it is not applicable to packaging forms with wire bonding on four sides. c) Do not use side walls, only use magnetic shielding sheets on the top and bottom. This solution is simple and easy to implement, with low cost, but it can only shield the magnetic field in the horizontal direction, and the shielding effect is not the best. Summary of the Utility Model

[0004] The magnetic field shielding packaging structure provided by the utility model can effectively reduce the process difficulty of magnetic field shielding packaging on the premise of ensuring the shielding effect.

[0005] The utility model provides a magnetic field shielding packaging structure, including:

[0006] A packaging frame with packaging pins;

[0007] An interposer is arranged on the packaging frame. The interposer has an inner electrode and an outer electrode, and the inner electrode and the outer electrode are arranged at intervals. The inner electrode and the outer electrode are electrically connected through metal wires arranged in the interposer; the outer electrode is electrically connected to the packaging pin;

[0008] A shielding gasket is arranged on the interposer. The shielding gasket has a first through hole corresponding to the inner electrode;

[0009] A chip is disposed on the shielding gasket, and electrodes of the chip are electrically connected to the inner electrodes through the first through holes;

[0010] A magnetic shielding cover, the bottom of the magnetic shielding cover has a concave accommodating space for accommodating the chip, the bottom edge of the magnetic shielding cover is in contact with the shielding gasket, and the edge of the magnetic shielding cover is disposed at an interval between the inner electrode and the outer electrode.

[0011] Optionally, there is a gap between the magnetic shielding cover and the chip.

[0012] Optionally, the magnetic shielding cover is provided with second through holes penetrating the top or side walls, and the second through holes are used for the encapsulation material to fill the accommodating space through the second through holes during the encapsulation process.

[0013] Optionally, a first groove is provided on the upper surface of the interposer, and the shielding gasket is formed in the first groove by a semiconductor manufacturing process;

[0014] Alternatively, the upper surface of the interposer is a plane, and the shielding gasket is adhered to the upper surface of the interposer.

[0015] Optionally, the magnetic shielding cover and the shielding gasket are formed by using a soft magnetic material.

[0016] Optionally, the magnetic shielding cover and the shielding gasket are a combination of one or both of permalloy and iron.

[0017] Optionally, the electrodes of the chip are electrically connected to the inner electrodes by wire bonding or flip chip bonding.

[0018] Optionally, the shielding gasket has a plurality of first through holes, wherein each first through hole corresponds to one inner electrode; or,

[0019] The shielding gasket has a plurality of first through holes, the first through holes are strip-shaped through holes, and each strip-shaped through hole corresponds to a plurality of inner electrodes; or,

[0020] The shielding gasket has one first through hole, and the area corresponding to the first through hole includes all the inner electrodes.

[0021] Optionally, the outer electrodes of the interposer are wire-bonded to the package pins of the package frame.

[0022] Optionally, the magnetic shielding cover includes four side walls and a top wall, the four side walls are perpendicular to each other in pairs, and the top wall is perpendicular to each of the side walls.

[0023] With the technical solution provided by this application, the interposer can be manufactured using existing semiconductor processes, and the mature manufacturing process can ensure extremely low costs and extremely high yields. In the technical solution provided by this application, the silicon-based interposer packaging process is exactly the same as that of ordinary chips, and the development difficulty of its packaging process is extremely low. At the same time, in this application, due to the adoption of a completely closed packaging structure, the magnetic shielding performance of the package can be effectively ensured. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 Schematic diagram of a magnetic field shielding package structure according to an embodiment of the present invention;

[0025] Figure 2 Schematic diagram of a magnetic field shielding package structure according to another embodiment of the present invention;

[0026] Figure 3 Schematic diagram of a magnetic field shielding package structure according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0027] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0028] An embodiment of the present invention provides a magnetic field shielding package structure, as Figures 1-3 shown, including:

[0029] A packaging frame V having packaging pins;

[0030] An interposer I disposed on the packaging frame V. The interposer I has an inner electrode VI and an outer electrode VII, and the inner electrode VI and the outer electrode VII are spaced apart. The inner electrode VI and the outer electrode VII are electrically connected by a metal wire VIII disposed in the interposer I; the outer electrode VII is electrically connected to the packaging pins;

[0031] A shielding gasket II disposed on the interposer I. The shielding gasket II has a first through hole corresponding to the inner electrode VI;

[0032] A chip IV disposed on the shielding gasket II. The electrodes of the chip IV are electrically connected to the inner electrode VI through the first through hole;

[0033] Magnetic shielding cover III, the bottom of the magnetic shielding cover III has a concave accommodation space for accommodating the chip IV, the bottom edge of the magnetic shielding cover III contacts the shielding gasket II, and the edge of the magnetic shielding cover III is arranged at the interval position between the inner electrode VI and the outer electrode VII.

[0034] Through the technical solution provided in the embodiment of the present application, the interposer I can be manufactured by using the existing semiconductor process, and the mature manufacturing process can ensure extremely low cost and extremely high yield. In the technical solution provided in the embodiment of the present application, the silicon-based interposer packaging process is exactly the same as the packaging process of the ordinary chip IV, and the development difficulty of its packaging process is extremely low. At the same time, in the embodiment of the present application, due to the adoption of a completely closed packaging structure, the magnetic shielding performance of the packaging can be effectively ensured.

[0035] As an optional implementation manner, there is a space between the magnetic shielding cover III and the chip IV.

[0036] As an optional implementation manner, the magnetic shielding cover III is provided with a second through hole penetrating the top or the side wall, and the second through hole is used to allow the encapsulant to fill the accommodation space through the second through hole during the encapsulation process.

[0037] As an optional implementation manner, a first groove is provided on the upper surface of the interposer I, and the shielding gasket II is formed in the first groove by using a semiconductor manufacturing process;

[0038] Or, the upper surface of the interposer I is a plane, and the shielding gasket II is adhered to the upper surface of the interposer I.

[0039] As an optional implementation manner, the magnetic shielding cover III and the shielding gasket II are prepared and formed by using a soft magnetic material.

[0040] As an optional implementation manner, the magnetic shielding cover III and the shielding gasket II adopt a combination of one or two of permalloy and iron.

[0041] As an optional implementation manner, the electrodes of the chip IV and the inner electrode VI are bonded by wire bonding or flip chip bonding.

[0042] As an optional implementation manner, the shielding gasket II has a plurality of first through holes, wherein each first through hole corresponds to an inner electrode VI; or,

[0043] The shielding gasket II has a plurality of first through holes, the first through holes are strip-shaped through holes, and each strip-shaped through hole corresponds to a plurality of inner electrodes VI; or,

[0044] The shielding gasket II has a first through hole, and the area corresponding to the first through hole includes all the inner electrodes VI.

[0045] As an alternative embodiment, the outer electrode VII of the intermediate layer I and the package pins of the package frame V are wire-bonded.

[0046] As an alternative embodiment, the magnetic shielding cover III includes four side walls and a top wall, the four side walls are perpendicular to each other in pairs, and the top wall is perpendicular to each of the side walls.

[0047] As follows, an exemplary magnetic field shielding package structure is provided, specifically as follows:

[0048] The intermediate layer is placed on the package frame. Two groups of electrodes, namely outer electrodes and inner electrodes, are placed on the surface of the intermediate layer. Among them, the outer electrodes are the electrodes located outside the magnetic shielding cover after the outer wall of the package, and the inner electrodes are the electrodes located inside the magnetic shielding cover after the package is completed. The outer electrodes and the package pins of the package frame are wire-bonded.

[0049] The inner electrodes and the chip electrodes can be wire-bonded. The structure is as Figure 1 shown. The inner electrodes and the chip electrodes can also be bonded by flip-chip bonding. The structure is as Figure 2 or 3 shown. The outer electrodes and the inner electrodes are connected by metal wires, and the metal wires are placed inside the intermediate layer.

[0050] The shielding gasket can be placed on the intermediate layer. The structure is as Figure 1 or 2 shown; or a first groove can be provided on the intermediate layer, and the magnetic shielding gasket is placed in the first groove of the intermediate layer and fabricated together using semiconductor processes. The structure is as Figure 3 shown, thus omitting the separate processing of this part and the process of mounting this part in the subsequent packaging. The edge of the shielding gasket is located within the range surrounded by the outer electrodes. The shielding gasket needs to have openings at the vertical projections of the inner electrodes to facilitate the bonding between the chip electrodes and the inner electrodes. If there are many inner electrodes, elongated holes can be provided to expose multiple inner electrodes at one time. Alternatively, a complete through hole can also be opened on the magnetic shielding gasket at the position corresponding to the chip electrodes to expose all the inner electrodes.

[0051] The chip is placed in the middle area on the shielding gasket, so that after the package is completed, the chip is in the space surrounded by the shielding gasket and the magnetic shielding cover.

[0052] The magnetic shielding cover is placed on the shielding gasket. The magnetic shielding cover can have openings to facilitate the full flow of the encapsulant into the magnetic shielding cover during the encapsulation process.

[0053] When the shielding gasket is independently prepared and placed on the upper surface of the interposer, the entire packaging process is as follows:

[0054] The interposer is prepared on a silicon wafer using semiconductor processes to form an interposer with internal electrodes, external electrodes, and metal wires;

[0055] Using chip packaging processes, such as thinning and dicing, the interposer is bonded to the packaging frame; and wire bonding is performed between the external electrodes of the interposer and the packaging pins on the packaging frame;

[0056] The shielding gasket is bonded to the interposer, and the first through-hole on the shielding gasket needs to be aligned with the internal electrodes of the interposer;

[0057] The chip is bonded to the shielding gasket. The internal electrodes of the interposer and the chip electrodes can be wire-bonded, or after aligning the chip electrodes with the internal electrodes, flip-chip bonding can be used for bonding.

[0058] The magnetic shielding cover is bonded to the shielding gasket in an inverted manner. At this time, the internal electrodes are located inside the magnetic shielding cover, and the external electrodes are located outside the magnetic shielding cover.

[0059] All components are encapsulated with molding compound to form the packaged chip.

[0060] When a first groove is provided on the upper surface of the interposer and the shielding gasket is prepared in the first groove using semiconductor processes, the entire packaging process is as follows:

[0061] The interposer is prepared on a silicon wafer using semiconductor processes to form an interposer with internal electrodes, external electrodes, and metal wires;

[0062] The upper surface of the interposer is etched to form a groove, and a shielding gasket is formed in the groove using a magnetic shielding material. Among them, when etching the groove, the position corresponding to the first through-hole of the shielding gasket can be reserved without etching, so that the shielding gasket forms the first through-hole and is aligned with the internal electrodes of the interposer;

[0063] Using chip packaging processes, such as thinning and dicing, the interposer with the shielding gasket is bonded to the packaging frame; and wire bonding is performed between the external electrodes of the interposer and the packaging pins on the packaging frame;

[0064] The chip is bonded to the shielding gasket. The internal electrodes of the interposer and the chip electrodes can be wire-bonded, or after aligning the chip electrodes with the internal electrodes, flip-chip bonding can be used for bonding.

[0065] The magnetic shielding cover is bonded to the shielding gasket in an inverted manner. At this time, the internal electrodes are located inside the magnetic shielding cover, and the external electrodes are located outside the magnetic shielding cover.

[0066] All components are encapsulated with plastic encapsulant to form the encapsulated chip.

[0067] The above are only specific embodiments of the present utility model, but the protection scope of the present utility model is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present utility model should be covered within the protection scope of the present utility model. Therefore, the protection scope of the present utility model should be subject to the protection scope of the claims.

Claims

1. A magnetic field shielding packaging structure, characterized in that: include: A package frame having package pins; An interposer is arranged on the package frame, the interposer has an inner electrode and an outer electrode, the inner electrode and the outer electrode are arranged at an interval, the inner electrode and the outer electrode are electrically connected through a metal wire arranged in the interposer; the outer electrode is electrically connected to the package pin; A shielding gasket, disposed on the interposer, the shielding gasket having a first through hole corresponding to the inner electrode; A chip is arranged on the shielding gasket, and the electrode of the chip is electrically connected to the inner electrode through the first through hole; A magnetic shielding cover, wherein the bottom of the magnetic shielding cover has a concave accommodating space, the concave accommodating space is used to accommodate the chip, the bottom edge of the magnetic shielding cover is in contact with the shielding gasket, and the edge of the magnetic shielding cover is arranged at the interval between the inner electrode and the outer electrode.

2. The magnetic field shielding packaging structure according to claim 1, characterized in that: The magnetic shielding cover is spaced apart from the chip.

3. The magnetic field shielding packaging structure according to claim 2, characterized in that: The magnetic shield is provided with a second through hole penetrating the top or the side wall, and the second through hole is used to allow the molding compound to fill the accommodating space through the second through hole during the molding process.

4. The magnetic field shielding packaging structure according to claim 1, characterized in that: The upper surface of the interposer is provided with a first groove, and the shielding gasket is formed in the first groove by using a semiconductor manufacturing process; Alternatively, the upper surface of the intermediate layer is a plane, and the shielding gasket is bonded to the upper surface of the intermediate layer.

5. The magnetic field shielding packaging structure according to claim 1, characterized in that: The magnetic shielding cover and the shielding gasket are made of soft magnetic materials.

6. The magnetic field shielding packaging structure according to claim 5, characterized in that: The magnetic shielding cover and the shielding gasket are made of permalloy and iron or a combination of the two.

7. The magnetic field shielding packaging structure according to claim 1, characterized in that: The electrodes of the chip are bonded to the inner electrodes by wire bonding or flip-chip bonding.

8. The magnetic field shielding packaging structure according to claim 1, characterized in that: The shielding gasket has a plurality of first through holes, wherein each first through hole corresponds to an inner electrode; or, The shielding gasket has a plurality of first through holes, wherein the first through holes are strip-shaped through holes, and each strip-shaped through hole corresponds to a plurality of inner electrodes; or, The shielding gasket has a first through hole, and the area corresponding to the first through hole includes all the inner electrodes.

9. The magnetic field shielding packaging structure according to claim 1, characterized in that: The outer electrodes of the intermediate layer are bonded to the packaging pins of the packaging frame by wire bonding.

10. The magnetic field shielding packaging structure according to claim 1, characterized in that: The magnetic shield comprises four side walls and a top wall. The four side walls are vertically arranged in pairs, and the top wall is vertically arranged with respect to each of the side walls.

Images