A packaging structure and a circuit board

Abstract

The utility model discloses an encapsulation structure and circuit board. Encapsulation structure includes: the wafer to be encapsulated, plastic package layer and external pin, the plastic package layer covers the wafer to be encapsulated, the external pin sets up in the first surface of plastic package layer, and the external pin is electrically connected with the wafer to be encapsulated, the first surface of plastic package layer is provided with groove in the preset edge area, and the preset edge area is adjacent with the external pin, and the groove penetrates the second surface of plastic package layer, wherein, the second surface of plastic package layer surrounds the first surface of plastic package layer, and is connected with the first surface, the groove is used for setting up the conductive material, and makes the external pin connect with external circuit through the conductive material. The utility model embodiment makes the encapsulation structure connect with the external circuit board more stably through the conductive material, and avoids falling off.

Description

Technical Field

[0001] This utility model relates to the field of packaging technology, and in particular to a packaging structure and circuit board. Background Technology

[0002] With the development of technology, power devices, as core components in electrical energy processing and power handling, are being used more and more widely. The main functions of power devices are frequency conversion, voltage transformation, AC power amplification, and power management, playing a crucial role in the normal operation of equipment.

[0003] However, existing power devices are prone to detaching after being packaged and mounted on the circuit board, affecting their operation. Utility Model Content

[0004] This invention provides a packaging structure and circuit board that allows the packaging structure to be more securely connected to the external circuit board through conductive materials, preventing it from falling off.

[0005] According to one aspect of the present invention, a packaging structure is provided, comprising:

[0006] Wafer to be packaged, molding compound, and external pins;

[0007] The molding compound covers the wafer to be packaged, and the external pins are disposed on the first surface of the molding compound and are electrically connected to the wafer to be packaged.

[0008] A groove is provided in a predetermined edge area of ​​the first surface of the molding compound, the predetermined edge area is adjacent to the external pin, and the groove penetrates the second surface of the molding compound; wherein, the second surface of the molding compound surrounds the first surface of the molding compound and is connected to the first surface;

[0009] The groove is used to provide conductive material so that the external pins can be connected to the external circuit through the conductive material.

[0010] Optionally, a connecting layer is provided in the trench, the connecting layer covering the trench and extending from the trench to the external pin; the connecting layer is used to improve the adhesion between the conductive material and the molding layer.

[0011] Optionally, the preset edge area is adjacent to the preset edge of the external pin;

[0012] The preset edge area is provided with multiple grooves, which are arranged sequentially along the preset edge; or, the preset edge area is provided with one groove, which extends along the preset edge.

[0013] Optionally, the sidewalls of the trench are stepped surfaces, planes, or curved surfaces.

[0014] Optionally, the thickness of the connection layer is less than the thickness of the external pin.

[0015] Optionally, the connection layer is made of the same material as the external pin.

[0016] Optionally, the external pins include a first external pin, a second external pin, and a third external pin;

[0017] The first external pin includes a first body portion and at least two first interposer portions connected to the first body portion, and the second external pin includes a second body portion and at least two second interposer portions connected to the second body portion. The first body portion and the second body portion extend along a first direction, and the first interposer portions and the second interposer portions extend along a second direction and are located between the first body portion and the second body portion.

[0018] Along the first direction, the first insertion finger and the second insertion finger are arranged alternately in sequence, and the third external pin is located between the edge of the first main body and a second insertion finger; wherein, the first direction and the second direction intersect each other;

[0019] A portion of the preset edge region is adjacent to the first main body portion, and a portion of the preset edge region is adjacent to the second main body portion.

[0020] Optionally, the packaging structure may also include:

[0021] Heat dissipation components;

[0022] The heat sink is disposed on the side of the wafer to be packaged away from the external pins. The molding compound covers the heat sink, and a portion of the heat sink away from the surface of the wafer to be packaged exposes the molding compound.

[0023] According to another aspect of the present invention, a circuit board is provided, comprising:

[0024] The substrate and the packaging structure described in any embodiment of this utility model;

[0025] The trench of the packaging structure is provided with conductive material, which extends from the trench to the surface of the external pin. The packaging structure is electrically connected to the preset pin on the surface of the substrate through the conductive material.

[0026] Optionally, the conductive material is tin.

[0027] This embodiment of the invention features a groove formed at a predetermined edge area on the first surface of the molding compound layer. The groove extends through the second surface of the molding compound layer and is used to house a conductive material, allowing external pins to connect to external circuits via the conductive material. By creating the groove, the conductive material can be placed within it. Due to the larger surface area of ​​the groove, the contact area between the conductive material and the encapsulation layer is increased, thereby improving the connection stability between the conductive material, the molding compound layer, and the external pins. Furthermore, the groove can hold a greater amount of conductive material, allowing the encapsulation structure to connect more securely to the external circuit board, preventing detachment.

[0028] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of this utility model, nor is it intended to limit the scope of this utility model. Other features of this utility model will become readily apparent from the following description. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 This is a cross-sectional schematic diagram of a packaging structure provided in an embodiment of this utility model.

[0031] Figure 2 This is a top view of a packaging structure provided in an embodiment of the present utility model.

[0032] Figure 3 This is a schematic diagram of the connection between a packaging structure and an external circuit provided in an embodiment of this utility model.

[0033] Figure 4 This is a top view of the encapsulation structure after the conductive material is applied, as provided in this embodiment of the utility model.

[0034] Figure 5 This is a top view of another packaging structure provided in this utility model embodiment.

[0035] Figure 6 This is a cross-sectional schematic diagram of another packaging structure provided in this utility model embodiment. Detailed Implementation

[0036] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0037] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this utility model are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the utility model described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0038] This embodiment provides a packaging structure. Figure 1 This is a cross-sectional schematic diagram of a packaging structure provided in an embodiment of this utility model. Figure 2 This is a top view of a packaging structure provided in an embodiment of the present invention, with reference to... Figure 1 and Figure 2 ,include:

[0039] The wafer to be packaged is 10, the molding layer is 30, and the external pins are 40.

[0040] A molding compound 30 covers the wafer 10 to be packaged, and external pins 40 are disposed on the first surface 301 of the molding compound 30. The external pins 40 are electrically connected to the wafer 10 to be packaged.

[0041] A groove 31 is provided on the preset edge region 101 of the first surface 301 of the molding compound 30. The preset edge region 101 is adjacent to the external pin 40. The groove 31 penetrates the second surface 302 of the molding compound 30. The second surface 302 of the molding compound 30 surrounds the first surface 301 of the molding compound 30 and is connected to the first surface 301. The groove 31 is used to provide a conductive material so that the external pin 40 is connected to an external circuit through the conductive material.

[0042] In this design, the wafer 10 to be packaged is a power chip, which is not limited to GaN chips but can also be Si chips, SiC chips, or GaAS chips. The packaging structure may include one, two, or more wafers 10 to be packaged, which can be connected via bumping, wire bonding, copper clips, or aluminum strips. A molding compound 30 is used to encapsulate the wafer 10. External pins 40 are used to bring out the pins of the wafer 10 to be packaged and connect them to external circuits. The external pins 40 are made of conductive materials; for example, copper or other metals with good conductivity are used.

[0043] Figure 3 This is a schematic diagram illustrating the connection between a packaging structure and an external circuit according to an embodiment of the present invention. Figure 4 This is a top view of the encapsulation structure after the conductive material is applied, as provided in an embodiment of this utility model. (Reference) Figure 3 and Figure 4 The trench 31 is used to accommodate conductive material 62, such as tin. The conductive material 62 fills the trench 31 and extends from it to the surface of the external pin 40, connecting with and connecting the external pin 40 to the external circuit board 70. The trench 31 penetrates the second surface 302 of the molding compound 30, meaning it extends towards the edge of the first surface 301 away from the external pin 40 and penetrates that edge. By providing the trench 31, the conductive material 62 can be disposed within it. Due to the large surface area of ​​the trench 31, the contact area between the conductive material 62 and the molding compound 30 is large, thereby improving the connection stability between the conductive material 62 and the molding compound 30 and the external pin 40. Furthermore, a larger amount of conductive material 62 can be disposed within the trench 31, allowing the package structure to be more securely connected to the external circuit board 70 through the increased amount of conductive material 62, preventing detachment.

[0044] This embodiment of the invention provides a groove 31 in a predetermined edge region 101 of the first surface 301 of the molding compound 30. The groove 31 penetrates the second surface 302 of the molding compound 30. The groove 31 is used to house a conductive material 62, allowing the external pin 40 to be connected to the external circuit 70 via the conductive material 62. By providing the groove 31, the conductive material 62 can be disposed within the groove 31. Due to the large surface area of ​​the groove 31, the contact area between the conductive material 62 and the molding compound 30 is large, thereby improving the connection stability between the conductive material 62 and the molding compound 30 and the external pin 40. Furthermore, a larger amount of conductive material 62 can be disposed within the groove 31, allowing the package structure to be more securely connected to the external circuit board 70 via the conductive material 62, preventing detachment.

[0045] Based on the above embodiments, optionally, a connecting layer 61 is provided in the trench 31, the connecting layer 61 covers the trench 31 and extends from the inside of the trench 31 to the external pin 40; the connecting layer 61 is used to improve the bonding force between the conductive material 62 and the molding layer 30.

[0046] Specifically, the connection layer 61 can be a metal layer or a layer of other materials. For example, the material of the connection layer 61 can be the same as the material of the external pin 40; for example, the connection layer 61 can be a copper layer or an aluminum layer. The connection layer 61 can be deposited on the surface of the molding compound 30 by processes such as electroplating.

[0047] By setting the connection layer 61, the bonding force between the conductive material 62 and the molding layer 30 can be further increased, and the connection stability between the conductive material and the molding layer 30 and the external pins 40 can be further improved, so that the package structure can be more firmly connected to the external circuit board 70 through the conductive material 62, and avoid falling off.

[0048] Figure 5 This is a top view of another packaging structure provided by an embodiment of the present invention. Optionally, based on the above embodiments, please continue to refer to... Figure 2 and Figure 5 The preset edge region 101 is adjacent to the preset edge 401 of the external pin 40;

[0049] The preset edge area 101 is provided with multiple grooves 31, and the multiple grooves 31 are arranged sequentially along the preset edge 401. Figure 2 Alternatively, a groove 31 may be provided in the preset edge area 101, and the groove 31 extends along the preset edge 401. Figure 5 ).

[0050] Specifically, multiple grooves 31 are provided along the preset edge 401, and each groove 31 is provided with conductive material. The external pin 40 is electrically connected to the external circuit board through the conductive material in the multiple grooves 31. The external pin 40 is connected to the external circuit board at multiple points, which can reduce connection stress and prevent detachment.

[0051] In addition, refer to Figure 5 In order to increase the contact area between the conductive material and the molding layer 30, the external pins 40 and the external circuit board, and reduce the contact resistance, only a large trench 31 can be set.

[0052] Figure 6 This is a cross-sectional schematic diagram of another packaging structure provided by an embodiment of the present invention. Optionally, based on the above embodiments, refer to... Figure 1 and Figure 6 The sidewall of the trench 31 adjacent to the external pin 40 is a stepped surface, a plane, or a curved surface.

[0053] For details, please refer to Figure 1 The sidewalls of the groove 31 are flat, which can reduce the difficulty of manufacturing the groove 31.

[0054] refer to Figure 6 The sidewalls of the groove 31 are stepped or curved, such as arc surfaces, which can increase the area of ​​the sidewalls, further increase the contact area between the conductive material and the molding layer 30, and further improve the connection stability between the conductive material, the molding layer 30 and the external pins 40.

[0055] Based on the above embodiments, optionally, the thickness of the connection layer 61 is less than the thickness of the external pin 40.

[0056] Specifically, if the thickness of the connection layer 61 is too thick, it will occupy too much space in the trench 31, resulting in the trench 31 not being able to accommodate more conductive material. By setting the thickness of the connection layer 61 to be less than the thickness of the external pin 40, the bonding force between the conductive material and the molding layer 30 can be increased, while avoiding the connection layer 61 occupying too much space in the trench 31. This ensures that more conductive material can be accommodated in the trench 31, improving the connection stability between the package structure and the external circuit board.

[0057] Based on the above embodiments, optionally, the connecting layer 61 is an electroplated metal layer.

[0058] Specifically, the connecting layer 61 can be formed on the surface of the molding layer 30 by processes such as electroplating. For example, the connecting layer 61 can be a copper layer or an aluminum layer.

[0059] Based on the above embodiments, optionally, the connection layer 61 and the external pin 40 are made of the same material.

[0060] With this configuration, the connection layer 61 can be fabricated using the same process as the external pin 40, reducing process costs.

[0061] Based on the above embodiments, optionally, refer to Figure 2 The external pins include a first external pin 41, a second external pin 42, and a third external pin 43;

[0062] The first external pin 41 includes a first body portion 411 and at least two first interposer portions 412 connected to the first body portion 411. The second external pin 42 includes a second body portion 421 and at least two second interposer portions 422 connected to the second body portion 421. The first body portion 411 and the second body portion 412 extend along a first direction X, and the first interposer portions 412 and the second interposer portions 422 extend along a second direction Y and are located between the first body portion 411 and the second body portion 421.

[0063] Along the first direction X, the first insertion part 412 and the second insertion part 422 are arranged alternately in sequence, and the third external pin 43 is located between the edge of the first main body part 411 and a second insertion part 422; wherein, the first direction X and the second direction Y intersect each other;

[0064] A portion of the preset edge area 101 is adjacent to the first main body portion 411, and a portion of the preset edge area 101 is adjacent to the second main body portion 421.

[0065] Specifically, the first external pin 41 is comb-shaped, the second external pin 42 is comb-shaped, and the first insertion part 412 and the second insertion part 422 are arranged alternately, so that the first external pin 41 and the second external pin 42 have a large area, which improves the heat dissipation speed. The first external pin 41 and the second external pin 42 are widely distributed, so that the first external pin 41 and the second external pin 42 can be connected to the wafer 10 to be packaged at a suitable position. This helps to shorten the connection path between the wafer 10 to be packaged and the first external pin 41 and the second external pin 42, so that the first external pin 41 and the second external pin 42 can collect signals nearby, reduce product resistance, and make the current distribution more uniform.

[0066] Furthermore, since the third external pin 43 is smaller than the first external pin 41 and the second external pin 42, placing the third external pin 43 between the edge of the first main body portion 411 and a second interdigitated portion 422 can prevent the third external pin 43 from being easily detached due to stress when placed at the corner, thereby improving system stability.

[0067] Both the first main body 411 and the second main body 421 have a large length, making them prone to detachment after being connected to the external circuit board. By setting a portion of the preset edge area 101 adjacent to the first main body 411 and a portion of the preset edge area 101 adjacent to the second main body 421, that is, the groove 31 is set in the edge area adjacent to the first main body 411 and the second main body 421, the connection stability between the first main body 411 and the external circuit board can be increased, and the connection stability between the second main body 421 and the external circuit board can be increased.

[0068] Based on the above embodiments, optionally, the plurality of first insert fingers 412 include first edge insert fingers 51, and the plurality of second insert fingers 422 include second edge insert fingers 52.

[0069] The first finger portions 412 other than the first edge finger portion 51 and the second finger portions 422 other than the second edge finger portion 52 are located between the first edge finger portion 51 and the second edge finger portion 52 along the first direction X.

[0070] The width of the first edge insertion finger portion 51 and the second edge insertion finger portion 52 along the first direction X is greater than the width of the other first insertion finger portion 412 along the first direction X, and is greater than the width of the other second insertion finger portion 422 along the first direction X.

[0071] Specifically, the third external pin 42 is located between the first main body portion 41 and the second edge insertion portion 52. The first edge insertion portion 51 is located at the edge of the first external pin 41, and the second edge insertion portion 52 is located at the edge of the second external pin 42. Therefore, the first edge insertion portion 51 and the second edge insertion portion 52 can be set to a wider width, thereby further increasing the heat dissipation area.

[0072] Based on the above embodiments, optionally, refer to Figure 1 The packaging structure also includes:

[0073] Heat sink 20;

[0074] The heat sink 20 is disposed on the side of the wafer 10 to be packaged away from the external pin 40. The molding compound 30 covers the heat sink 20, and a portion of the heat sink 20 away from the surface of the wafer 10 to be packaged is exposed by the molding compound 30.

[0075] By setting a heat sink 20 on the side of the wafer 10 to be packaged away from the external pin 40, the wafer 10 to be packaged can dissipate heat through the heat sink 20 and the external pin 40, achieving double-sided heat dissipation. The part of the surface of the heat sink 20 away from the wafer 10 to be packaged exposes the molding compound 30. On the one hand, the heat dissipation effect of the heat sink 20 is better. On the other hand, the molding compound 30 covers part of the surface of the heat sink 20, so that the coverage area of ​​the molding compound 30 on the side where the heat sink 20 is located is larger, which is more conducive to the molding compound 30 formation and makes the structure of the entire package more stable.

[0076] This utility model embodiment also provides a circuit board, see reference. Figure 3 The circuit board includes: a substrate 71 and the packaging structure described in any embodiment of the present invention; a conductive material 62 is disposed in the trench 31 of the packaging structure, the conductive material 62 extends from the trench 31 to the surface of the external pin 40, and the packaging structure is electrically connected to the preset pins on the surface of the substrate 71 through the conductive material 62.

[0077] This embodiment of the invention provides a groove 31 on a predetermined edge region 101 of the first surface 301 of the molding compound 30. The groove 31 penetrates the second surface 302 of the molding compound 30. A conductive material 62 is disposed within the groove 31, and the external pin 40 is connected to the substrate 71 through the conductive material 62. By providing the groove 31, the conductive material can be disposed within it. Due to the large surface area of ​​the groove 31, the contact area between the conductive material 62 and the molding compound 30 is large, thereby improving the connection stability between the conductive material 62 and the molding compound 30 and the external pin 40. Furthermore, a larger amount of conductive material can be disposed within the groove 31, allowing the encapsulation structure to be more securely connected to the substrate 71 through the conductive material 62, preventing detachment.

[0078] Optionally, based on the above embodiments, the conductive material 62 may be tin.

[0079] In addition, conductive material 62 can also be other metallic materials with good conductivity that also serve as connectors.

[0080] It should be understood that the various forms of the process shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this utility model can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this utility model can be achieved, and this is not limited herein.

[0081] The specific embodiments described above do not constitute a limitation on the scope of protection of this utility model. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the scope of protection of this utility model.

Claims

1. A packaging structure, characterized in that, include: Wafer to be packaged, molding compound, and external pins; The molding compound covers the wafer to be packaged, and the external pins are disposed on the first surface of the molding compound and are electrically connected to the wafer to be packaged. A groove is provided in a predetermined edge area of ​​the first surface of the molding compound, the predetermined edge area is adjacent to the external pin, and the groove penetrates the second surface of the molding compound; wherein, the second surface of the molding compound surrounds the first surface of the molding compound and is connected to the first surface; The groove is used to provide conductive material so that the external pins can be connected to the external circuit through the conductive material.

2. The packaging structure according to claim 1, characterized in that: A connecting layer is provided in the trench, the connecting layer covers the trench and extends from the trench to the external pin; the connecting layer is used to improve the adhesion between the conductive material and the molding layer.

3. The packaging structure according to claim 1, characterized in that: The preset edge area is adjacent to the preset edge of the external pin; The preset edge area is provided with multiple grooves, which are arranged sequentially along the preset edge; or, the preset edge area is provided with one groove, which extends along the preset edge.

4. The packaging structure according to claim 1, characterized in that: The sidewalls of the trench are stepped, flat, or curved.

5. The packaging structure according to claim 2, characterized in that: The thickness of the connection layer is less than the thickness of the external pin.

6. The packaging structure according to claim 2, characterized in that: The connection layer is made of the same material as the external pin.

7. The packaging structure according to claim 1, characterized in that: The external pins include a first external pin, a second external pin, and a third external pin; The first external pin includes a first body portion and at least two first interposer portions connected to the first body portion, and the second external pin includes a second body portion and at least two second interposer portions connected to the second body portion. The first body portion and the second body portion extend along a first direction, and the first interposer portions and the second interposer portions extend along a second direction and are located between the first body portion and the second body portion. Along the first direction, the first insertion finger and the second insertion finger are arranged alternately in sequence, and the third external pin is located between the edge of the first main body and a second insertion finger; wherein, the first direction and the second direction intersect each other; A portion of the preset edge region is adjacent to the first main body portion, and a portion of the preset edge region is adjacent to the second main body portion.

8. The packaging structure according to claim 1, characterized in that, Also includes: Heat dissipation components; The heat sink is disposed on the side of the wafer to be packaged away from the external pins. The molding compound covers the heat sink, and a portion of the heat sink away from the surface of the wafer to be packaged exposes the molding compound.

9. A circuit board, characterized in that, include: The substrate and the packaging structure as described in any one of claims 1-8; The trench of the packaging structure is provided with conductive material, which extends from the trench to the surface of the external pin. The packaging structure is electrically connected to the preset pin on the surface of the substrate through the conductive material.

10. The circuit board according to claim 9, characterized in that: The conductive material is tin.

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