A magnetic shielding packaging structure and a magnetic random access memory

Abstract

The utility model discloses a kind of magnetic shielding packaging structure and magnetic random access memory, applied to chip packaging field, applied to four side lead bonding magnetic shielding packaging structure, wherein magnetic shielding structure side wall includes four magnetic shielding cylinder, four magnetic shielding cylinder is set at the intersection of every two lead bonding edges of chip correspondingly;The projection of magnetic shielding cylinder on bottom magnetic shielding layer and top magnetic shielding layer, all are curved into shape shape;Every magnetic shielding cylinder is correspondingly set in the outside of two lead bonding edges of chip intersection along the two extension edges of curved into shape shape;Every lead bonding edge of chip, through lead, pass through the reserved area between adjacent magnetic shielding cylinder, with lead frame bonding connection.The utility model is by four magnetic shielding cylinder is set to have curved into shape shape section structure, can increase the cladding area of magnetic shielding structure to four side lead bonding chip, improve magnetic shielding effect.

Description

Technical Field

[0001] This utility model relates to the field of chip packaging, and in particular to a magnetically shielded packaging structure and a magnetic random access memory. Background Technology

[0002] Magnetic shielding is a critical issue in applications, and incorporating a magnetic shielding structure into the packaged chip is a common solution. Generally, magnetic shielding materials are used to surround the chip to achieve high magnetic shielding efficiency. However, the chip needs to be electrically connected to external pins via wire bonding or other methods. The core challenge of magnetically shielded packaging is achieving effective magnetic shielding while ensuring electrical connectivity.

[0003] Currently, there are many solutions for magnetic shielding structures, but they generally suffer from the following problems: 1. In pursuit of magnetic shielding efficiency, the magnetic shielding structure becomes very complex, resulting in low packaging operability; 2. In pursuit of packaging operability, the magnetic shielding structure is simplified, resulting in low magnetic shielding efficiency; 3. If both magnetic shielding efficiency and packaging operability are considered, then the magnetic shielding structure is only suitable for packaging processes with simple wire bonding, which limits the application of wire bonding. Utility Model Content

[0004] In view of this, the purpose of this utility model is to provide a magnetic shielding packaging structure and a magnetic random access memory, which solves the problems of complex magnetic shielding structure and low magnetic shielding efficiency in the prior art.

[0005] To solve the above-mentioned technical problems, this utility model provides a magnetic shielding packaging structure, applied to a magnetic shielding packaging structure with four-sided wire bonding, comprising:

[0006] Lead frame, bottom magnetic shielding layer, top magnetic shielding layer, and magnetic shielding structure sidewall and chip disposed between the bottom magnetic shielding layer and the top magnetic shielding layer;

[0007] The magnetic shielding structure sidewall includes four magnetic shielding pillars, which are correspondingly disposed at the intersection of every two lead bonding edges of the chip.

[0008] The projections of the magnetic shielding column onto the bottom magnetic shielding layer and the top magnetic shielding layer are both curved shapes;

[0009] Each of the magnetic shielding pillars extends along two sides of the bent shape, with one side disposed outside the corresponding wire bonding side among the two intersecting wire bonding sides of the chip, and the other side disposed outside the other wire bonding side.

[0010] Each of the wire bonding edges of the chip is bonded to the lead frame by passing through the gap between adjacent magnetic shielding pillars with a lead wire.

[0011] Optionally, the projections of the magnetic shielding column onto the bottom magnetic shielding layer and the top magnetic shielding layer are both L-shaped bends formed by right-angle bends.

[0012] Optionally, the projections of the magnetic shielding column onto the bottom magnetic shielding layer and the top magnetic shielding layer are both arc-shaped bends.

[0013] Optionally, the lead frame includes an inner electrode facing the chip, an outer pin away from the chip, and a metal wire connecting the inner electrode and the outer pin;

[0014] The spacing between adjacent metal lines gradually decreases along the direction from the outer pin to the inner electrode.

[0015] Optionally, the electrodes of the chip are located in the middle region of the wire bonding edge.

[0016] Optionally, the bottom magnetic shielding layer, the sidewall of the magnetic shielding structure, and the top magnetic shielding layer are bonded together with adhesive.

[0017] Optionally, the bottom magnetic shielding layer, the sidewall of the magnetic shielding structure, and the top magnetic shielding layer are all magnetic shielding structures made of soft magnetic materials.

[0018] This invention also provides a magnetic random access memory, including multiple magnetically shielded encapsulation structures as described above.

[0019] As can be seen, the magnetic shielding packaging structure provided by this utility model is applied to a magnetic shielding packaging structure with four-sided wire bonding. It includes a lead frame, a bottom magnetic shielding layer, a top magnetic shielding layer, and a magnetic shielding structure sidewall and a chip disposed between the bottom and top magnetic shielding layers. The magnetic shielding structure sidewall includes four magnetic shielding pillars, which are correspondingly disposed at the intersection points of every two wire bonding edges of the chip. The projections of the magnetic shielding pillars on the bottom and top magnetic shielding layers are both curved shapes. Each magnetic shielding pillar has two extended edges along its curved shape. One extended edge is disposed outside the corresponding wire bonding edge of the two intersecting wire bonding edges of the chip, and the other extended edge is disposed outside the other wire bonding edge. Each wire bonding edge of the chip is bonded to the lead frame by a wire passing through the empty area between adjacent magnetic shielding pillars. This invention increases the coverage area of ​​the magnetic shielding structure on the chip with four wire-bonded sides by setting the four magnetic shielding pillars as having a curved cross-section. This improves the magnetic shielding effect, especially the vertical magnetic shielding efficiency, without affecting the bonding connection between the chip and the external environment.

[0020] In addition, this invention also provides a magnetic random access memory, which has the same beneficial effects as described above. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0022] Figure 1 A schematic diagram of a magnetic shielding packaging structure provided in an embodiment of this utility model;

[0023] Figure 2 A schematic diagram of the structure of an L-shaped bend magnetic shielding column in a magnetic shielding encapsulation structure provided for an embodiment of this utility model;

[0024] Figure 3 A schematic diagram of a lead frame adapted to a structure for bonding with chip leads, provided in an embodiment of this utility model;

[0025] The annotations in the attached figures are explained as follows:

[0026] 11-Lead frame, 12-Bottom magnetic shielding layer, 13-Magnetic shielding structure sidewall, 14-Top magnetic shielding layer, 15-Chip, 21-Inner electrode, 22-Metal wire, 23-Outer pin. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0028] Please refer to Figure 1 , Figure 1 This is a schematic diagram of a magnetic shielding packaging structure provided in an embodiment of the present invention. This magnetic shielding packaging structure, applied to a four-sided wire bonding magnetic shielding packaging structure, may include:

[0029] Lead frame 11, bottom magnetic shielding layer 12, top magnetic shielding layer 14, and magnetic shielding structure sidewall 13 and chip 15 disposed between bottom magnetic shielding layer 12 and top magnetic shielding layer 14;

[0030] The magnetic shielding structure sidewall 13 includes four magnetic shielding pillars, which are respectively arranged at the intersection of every two lead bonding edges of the chip 15.

[0031] The projections of the magnetic shielding column onto the bottom magnetic shielding layer 12 and the top magnetic shielding layer 14 are both curved shapes.

[0032] Each magnetic shielding pillar has two extended sides along its curved shape. One extended side is located outside the corresponding wire bonding side among the two intersecting wire bonding sides of chip 15, and the other extended side is located outside the other wire bonding side.

[0033] Each lead bonding edge of chip 15 is bonded to lead frame 11 by passing through the gap between adjacent magnetic shielding pillars.

[0034] In this embodiment, the bottom magnetic shielding layer 12, the top magnetic shielding layer 14, and the magnetic shielding structure sidewall 13 can all be disposed on the lead frame 11, while the chip 15 is disposed in the space enclosed by the bottom magnetic shielding layer 12, the top magnetic shielding layer 14, and the magnetic shielding structure sidewall 13 to achieve magnetic shielding of the chip 15. In this embodiment, the magnetic shielding structure sidewall 13 includes four magnetic shielding pillars, and the magnetic shielding pillars are bent into a shape along a cross section parallel to the bottom magnetic shielding layer 12 or the top magnetic shielding layer 14. One extended edge of the bent shape is disposed on the outside of one of the two intersecting edges of the chip 15, and the other extended edge is disposed on the outside of the other of the two intersecting edges. That is, the magnetic shielding pillars mentioned in this embodiment not only form magnetic shielding of the chip 15 at a single point, but also form magnetic shielding of the chip 15 along a length of edge, increasing the effective encirclement length of the chip 15, thereby improving the magnetic shielding effect of the chip 15. Since the aforementioned magnetic shielding pillars are only located at the four corners of the chip 15, there is no shielding structure blocking the middle area near each side of the chip 15. The electrodes of the chip 15 can be directly connected to the lead frame 11 by wire bonding. In this embodiment, the packaging structure is a magnetic shielding packaging structure with four-sided wire bonding, that is, each side of the chip 15 is a wire bonding side for leading out leads.

[0035] Furthermore, to improve the space utilization of magnetic shielding pillars and reduce fabrication difficulty, reference can be made to... Figure 2 , Figure 2 This is a schematic diagram of an L-shaped magnetic shielding column in a magnetic shielding encapsulation structure provided by an embodiment of the present invention. The projections of the aforementioned magnetic shielding column onto the bottom magnetic shielding layer 12 and the top magnetic shielding layer 14 can both be L-shaped bends formed by right-angle bends.

[0036] The magnetic shielding column in this embodiment has an L-shaped bend, which is suitable for deployment in a limited space. It can improve the compactness of the magnetic shielding structure while ensuring the shielding performance of the magnetic shielding structure against external magnetic fields.

[0037] Furthermore, in order to facilitate the lead-out of the electrodes in the chip 15, the electrodes of the chip 15 can be located in the middle region of the wire bonding edge.

[0038] In this embodiment, the sidewall 13 of the magnetic shielding structure has a corresponding empty area in the middle region of each lead bonding edge of the chip 15. Therefore, the electrodes of the chip 15 are located in the middle region of each lead bonding edge, which makes it easier for the leads to lead the electrodes of the chip 15 to the lead frame 11, thus improving the convenience of bonding connection.

[0039] Furthermore, in order to improve the overall stability of the magnetic shielding structure while ensuring the ease of its fabrication, the bottom magnetic shielding layer 12, the sidewall 13 of the magnetic shielding structure, and the top magnetic shielding layer 14 can be bonded together with adhesive.

[0040] In this embodiment, the bottom magnetic shielding layer 12, the side wall 13 of the magnetic shielding structure, and the top magnetic shielding layer 14 are bonded together with glue, so as to achieve the overall stability of the magnetic shielding structure while ensuring ease of preparation and low preparation cost.

[0041] Furthermore, in order to reduce the impact of interference magnetic field noise on chip 15, the bottom magnetic shielding layer 12, the magnetic shielding structure sidewall 13 and the top magnetic shielding layer 14 can all be made of soft magnetic material magnetic shielding structure.

[0042] In this embodiment, by setting the magnetic shielding structure as a soft magnetic material magnetic shielding structure, the shielding effect against static magnetic fields and low-frequency magnetic fields can be improved, the influence of external interference magnetic field noise on chip 15 can be reduced, and thus the magnetic shielding performance can be improved. Specifically, this embodiment can use a magnetic shielding structure made of soft magnetic materials such as silicon steel or permalloy.

[0043] Furthermore, in order to ensure that the electrodes of chip 15 can be successfully led out, the width of the gap between adjacent magnetic shielding pillars can be set to 0.5 mm to 2 mm.

[0044] In this embodiment, by setting the width of the above-mentioned empty area to 0.5 mm to 2 mm, the magnetic shielding effect of the magnetic shielding pillar on the chip 15 is ensured on the one hand, and the electrodes of the chip 15 can be smoothly led out on the other hand.

[0045] Furthermore, in order to ensure the shielding performance of the magnetic shielding structure, the thickness of the sidewall 13 of the magnetic shielding structure can be set to 0.3 mm to 0.5 mm.

[0046] In this embodiment, by setting the thickness of the sidewall 13 of the magnetic shielding structure to 0.3 mm to 0.5 mm, the shielding performance of the magnetic shielding structure on the chip 15 is ensured.

[0047] The magnetic shielding packaging structure provided in this embodiment of the present invention is applied to a magnetic shielding packaging structure with four-sided wire bonding. It includes a lead frame 11, a bottom magnetic shielding layer 12, a top magnetic shielding layer 14, and a magnetic shielding structure sidewall 13 and a chip 15 disposed between the bottom magnetic shielding layer 12 and the top magnetic shielding layer 14. The magnetic shielding structure sidewall 13 includes four magnetic shielding pillars, which are correspondingly disposed at the intersection points of every two wire bonding edges of the chip 15. The projections of the magnetic shielding pillars onto the bottom magnetic shielding layer 12 and the top magnetic shielding layer 14 are both curved shapes. Each magnetic shielding pillar has two extended edges along its curved shape; one extended edge is disposed outside one of the two intersecting wire bonding edges of the chip 15, and the other extended edge is disposed outside the other wire bonding edge. Each wire bonding edge of the chip 15 is bonded to the lead frame 11 via a lead passing through the empty area between adjacent magnetic shielding pillars. This invention increases the coverage area of ​​the magnetic shielding structure on the four-sided wire-bonded chip 15 by setting the four magnetic shielding pillars as having a curved cross-section. This improves the magnetic shielding effect, especially the vertical magnetic shielding efficiency, without affecting the bonding connection between the chip 15 and the external components.

[0048] Furthermore, this embodiment of the invention sets the projections of the aforementioned magnetic shielding pillars onto the bottom magnetic shielding layer 12 and the top magnetic shielding layer 14 to be L-shaped bends formed by right-angle bends, which is suitable for placement in limited spaces, improving the compactness of the magnetic shielding structure while ensuring the shielding performance of the magnetic shielding structure against external magnetic fields. By setting the electrodes of the chip 15 in the middle region of each lead bonding edge, it is easy for the leads to bring the electrodes of the chip 15 to the lead frame 11, improving the convenience of bonding connections. The bottom magnetic shielding layer 12, the sidewalls 13 of the magnetic shielding structure, and the top magnetic shielding layer 14 are bonded and fixed with adhesive, ensuring the fabrication process... While maintaining simplicity and low manufacturing cost, the overall stability of the magnetic shielding structure is achieved. By setting the magnetic shielding structure as a soft magnetic material, the shielding effect against static magnetic fields and low-frequency magnetic fields can be improved, reducing the impact of external interference magnetic field noise on the chip 15, thereby improving the magnetic shielding performance. By setting the width of the above-mentioned empty area to 0.5 mm to 2 mm, the magnetic shielding effect of the magnetic shielding pillar on the chip 15 is ensured on the one hand, and the electrodes of the chip 15 can be smoothly led out on the other hand. By setting the thickness of the sidewall 13 of the magnetic shielding structure to 0.3 mm to 0.5 mm, the shielding performance of the magnetic shielding structure on the chip 15 is ensured.

[0049] Example 2:

[0050] The following describes another magnetic shielding packaging structure provided by the present invention. The magnetic shielding packaging structure described below can be referred to in correspondence with the magnetic shielding packaging structure described above.

[0051] The magnetic shielding encapsulation structure provided in this embodiment of the invention differs from that in Embodiment 1 described above in that:

[0052] The projections of the magnetic shielding column onto the bottom magnetic shielding layer 12 and the top magnetic shielding layer 14 are both arc-shaped bends.

[0053] In this embodiment, the projection of the magnetic shielding column onto the bottom magnetic shielding layer 12 and the top magnetic shielding layer 14 is set to an arc-shaped curved shape, which can improve the uniformity of the interference magnetic field and avoid the interference magnetic field from being concentrated locally and affecting the chip 15.

[0054] Furthermore, to ensure a smooth connection between chip 15 and lead frame 11, reference can be made to... Figure 3 , Figure 3 This is a schematic diagram of a lead frame adapted to a structure for bonding with chip leads, provided by an embodiment of the present invention. The lead frame 11 may include an inner electrode 21 facing the chip 15, an outer pin 23 away from the chip 15, and a metal wire 22 connecting the inner electrode 21 and the outer pin 23;

[0055] The spacing between adjacent metal lines 22 gradually decreases along the direction from the outer pin 23 to the inner electrode 21.

[0056] In this embodiment, a bending portion is provided in the lead frame 11. The bending portion includes an inner electrode 21, an outer pin 23, and a metal wire 22 connecting the inner electrode 21 and the outer pin 23. This is adapted to each pad of the chip 15 in the magnetic shielding package structure, and the structure is located in the middle of the lead bonding edge. This improves the convenience of package structure layout and facilitates lead bonding connection.

[0057] The magnetic shielding packaging structure provided in this embodiment of the invention features a magnetic shielding pillar whose projections on the bottom magnetic shielding layer 12 and the top magnetic shielding layer 14 are both arc-shaped bends. This improves the uniformity of the interfering magnetic field and prevents localized concentration of the interfering magnetic field from affecting the chip 15. Furthermore, by providing a bending portion in the lead frame 11, which includes an inner electrode 21, an outer pin 23, and a metal wire 22 connecting the inner electrode 21 and the outer pin 23, the structure adapts to each pad of the chip 15 in the magnetic shielding packaging structure. This structure, with each pad located in the middle of its respective lead bonding edge, improves the ease of packaging layout and facilitates lead bonding connections.

[0058] In one feasible embodiment, the above-described magnetic shielding encapsulation structure may specifically include the following structure:

[0059] Lead frame, bottom magnetic shielding layer, top magnetic shielding layer, and magnetic shielding structure sidewalls disposed between the bottom magnetic shielding layer and the top magnetic shielding layer, chip;

[0060] The magnetic shielding structure sidewall includes four magnetic shielding pillars, which are respectively set at the intersection of every two lead bonding edges of the chip;

[0061] The projections of the magnetic shielding column onto the bottom and top magnetic shielding layers are both L-shaped bends formed by right-angle bends.

[0062] Each magnetic shielding pillar has two extended sides along its curved shape. One extended side is located outside the corresponding wire bonding side among the two intersecting wire bonding sides of the chip, and the other extended side is located outside the other wire bonding side.

[0063] Each wire bonding edge of the chip is bonded to the lead frame by passing through the gap between adjacent magnetic shielding pillars with a lead wire;

[0064] The lead frame includes an inner electrode close to the chip, an outer pin away from the chip, and metal wires connecting the inner electrode and the outer pin; the spacing between adjacent metal wires gradually decreases along the direction from the outer pin to the inner electrode, and the chip's electrode is located in the middle region of the lead bonding edge.

[0065] The bottom magnetic shielding layer, the side wall of the magnetic shielding structure, and the top magnetic shielding layer are bonded together with adhesive; the bottom magnetic shielding layer, the side wall of the magnetic shielding structure, and the top magnetic shielding layer are all made of soft magnetic materials; the width of the gap between adjacent magnetic shielding columns is 0.5 mm to 2 mm; the thickness of the side wall of the magnetic shielding structure is 0.3 mm to 0.5 mm.

[0066] The magnetic random access memory provided in the embodiments of this utility model is described below. The magnetic random access memory described below can be referred to in correspondence with the magnetic shielding packaging structure described above.

[0067] The magnetic random access memory provided in this embodiment of the present invention may include multiple magnetically shielded packaging structures as described above.

[0068] This embodiment further improves the optimization effect of the magnetic shielding structure by setting multiple magnetic shielding encapsulation structures as described above in the magnetic random access memory, thereby improving the storage stability and read / write accuracy of the magnetic random access memory.

[0069] The magnetic random access memory (MRMemory) provided by this invention includes multiple magnetically shielded packaging structures as described above. By configuring the four magnetic shielding pillars with a bent cross-section, this invention increases the coverage area of ​​the magnetic shielding structure on the four-sided wire-bonded chip, improving the magnetic shielding effect, especially the vertical magnetic shielding efficiency, without affecting the chip's bonding connection to external components. By including multiple magnetically shielded packaging structures as described above in the MRMemory, the optimization effect of the magnetic shielding packaging structure is further improved, thereby enhancing the storage stability and read / write accuracy of the MRMemory.

[0070] The various embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0071] Furthermore, it should be noted that in this document, relationships such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprising," "including," or any other variations are intended to cover non-exclusive inclusion.

[0072] The above provides a detailed description of the magnetic shielding packaging structure and magnetic random access memory provided by this utility model. Specific examples have been used to illustrate the principle and implementation of this utility model. The description of the above embodiments is only for the purpose of helping to understand the structure and core idea of ​​this utility model. At the same time, for those skilled in the art, there will be changes in the specific implementation and application scope based on the idea of ​​this utility model. Therefore, the content of this specification should not be construed as a limitation of this utility model.

Claims

1. A magnetic shielding packaging structure, characterized by, Magnetic shielding packaging structures for four-sided wire bonding include: Lead frame, bottom magnetic shielding layer, top magnetic shielding layer, and magnetic shielding structure sidewall and chip disposed between the bottom magnetic shielding layer and the top magnetic shielding layer; The magnetic shielding structure sidewall includes four magnetic shielding pillars, which are correspondingly disposed at the intersection of every two lead bonding edges of the chip. The projections of the magnetic shielding column onto the bottom magnetic shielding layer and the top magnetic shielding layer are both curved shapes; Each of the magnetic shielding pillars extends along two sides of the bent shape, with one side disposed outside the corresponding wire bonding side among the two intersecting wire bonding sides of the chip, and the other side disposed outside the other wire bonding side. Each of the wire bonding edges of the chip is bonded to the lead frame by passing through the gap between adjacent magnetic shielding pillars with a lead wire.

2. The magnetic shielding package structure of claim 1, wherein, The projections of the magnetic shielding column onto the bottom magnetic shielding layer and the top magnetic shielding layer are both L-shaped bends formed by right-angle bends.

3. The magnetic shielding package structure of claim 1, wherein, The projections of the magnetic shielding column onto the bottom magnetic shielding layer and the top magnetic shielding layer are both arc-shaped bends.

4. The magnetic shielding package structure of claim 1, wherein, The lead frame includes an inner electrode facing the chip, an outer pin away from the chip, and a metal wire connecting the inner electrode and the outer pin. The spacing between adjacent metal lines gradually decreases along the direction from the outer pin to the inner electrode.

5. The magnetic shielding package structure of claim 1, wherein, The electrodes of the chip are located in the middle region of the wire bonding edge.

6. The magnetic shielding encapsulation structure according to claim 1, characterized in that, The bottom magnetic shielding layer, the sidewall of the magnetic shielding structure, and the top magnetic shielding layer are bonded together with adhesive.

7. The magnetic shielding package structure of claim 1, wherein, The bottom magnetic shielding layer, the sidewalls of the magnetic shielding structure, and the top magnetic shielding layer are all magnetic shielding structures made of soft magnetic materials.

8. A magnetic random access memory, comprising: It includes multiple magnetic shielding encapsulation structures as described in any one of claims 1 to 7.

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