A packaging structure

Abstract

The utility model discloses a kind of packaging structures. Packaging structure includes: to be packaged wafer, heat dissipation piece, plastic package layer and external pin;The heat dissipation piece is set on the side of the to be packaged wafer, the plastic package layer covers the to be packaged wafer and the heat dissipation piece, and the part area of the heat dissipation piece far from the surface of the to be packaged wafer exposes the plastic package layer;The external pin is set on the side of the to be packaged wafer far from the heat dissipation piece, and it is set on the side of the plastic package layer far from the to be packaged wafer, and the external pin is electrically connected with the to be packaged wafer. The utility model can improve the heat dissipation speed of packaging structure, and promote working performance.

Description

Technical Field

[0001] This utility model relates to the field of packaging technology, and in particular to a packaging structure. 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] Existing power devices have slow heat dissipation after packaging, which can easily lead to overheating and affect their performance. Utility Model Content

[0004] This invention provides a packaging structure to improve heat dissipation speed and enhance working performance.

[0005] According to one aspect of the present invention, a packaging structure is provided, characterized in that it comprises:

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

[0007] The heat sink is disposed on one side of the wafer to be packaged, the molding compound covers the wafer to be packaged and the heat sink, and a portion of the heat sink away from the surface of the wafer to be packaged is exposed by the molding compound.

[0008] The external pin is located on the side of the wafer to be packaged away from the heat sink, and on the side of the molding layer away from the wafer to be packaged. The external pin is electrically connected to the wafer to be packaged.

[0009] Optionally, the heat sink includes a thinned portion and a protrusion, the thinned portion surrounding the protrusion; the protrusion having a first distance from the surface of the wafer to be packaged away from the wafer to be packaged, and the thinned portion having a second distance from the surface of the wafer to be packaged away from the wafer to be packaged, the first distance being greater than the second distance;

[0010] The molding compound covers the thinned portion, and the protrusion is exposed away from the surface of the wafer to be packaged, thus exposing the molding compound.

[0011] Optionally, the surface of the molding layer away from the external pin is flush with the surface of the protrusion away from the external pin.

[0012] Optionally, the surface of the thinned portion adjacent to the wafer to be packaged is flush with the surface of the protrusion adjacent to the wafer to be packaged.

[0013] Optionally, the ratio of the thickness of the thinned portion to the thickness of the protrusion is greater than or equal to 1 / 3 and less than or equal to 3 / 4.

[0014] Optionally, the distance between the edge of the thinned portion away from the protrusion and the edge of the thinned portion adjacent to the protrusion is greater than or equal to 100 micrometers.

[0015] Optionally, the distance between the edge of the molding compound's vertical projection onto the surface of the wafer to be packaged adjacent to the heat sink and the edge of the heat sink's vertical projection onto the surface of the wafer to be packaged adjacent to the heat sink is greater than or equal to 100 micrometers.

[0016] Optionally, the heat sink covers the wafer to be packaged in a vertical projection.

[0017] A thermally conductive connection layer is provided between the heat sink and the wafer to be packaged.

[0018] Optionally, the external pins include a first external pin, a second external pin, and a third external pin;

[0019] 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.

[0020] 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.

[0021] Optionally, the plurality of first insert fingers include a first edge insert finger, and the plurality of second insert fingers include a second edge insert finger;

[0022] The other first insert finger portions, excluding the first edge insert finger portion, and the other second insert finger portions, excluding the second edge insert finger portion, are located between the first edge insert finger portion and the second edge insert finger portion along the first direction;

[0023] The width of the first edge insertion portion and the second edge insertion portion along the first direction is greater than the width of the other first insertion portions along the first direction, and is greater than the width of the other second insertion portions along the first direction.

[0024] This embodiment of the invention provides a heat sink on the side of the wafer to be packaged away from the external pins, allowing the wafer to dissipate heat through both the heat sink and the external pins, achieving double-sided heat dissipation. Furthermore, the portion of the heat sink's surface away from the wafer is exposed to the molding compound. This improves the heat dissipation effect of the heat sink and, because the molding compound covers a portion of the heat sink's surface, provides a larger coverage area on the side where the heat sink is located, which is more conducive to molding and makes the overall packaging structure more stable. It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of this invention, nor is it intended to limit the scope of this invention. Other features of this invention will become readily apparent from the following description. Attached Figure Description

[0025] 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.

[0026] Figure 1 This is a schematic diagram of a packaging structure provided in this utility model embodiment.

[0027] Figure 2 This is a top view of a packaging structure provided in an embodiment of the present utility model.

[0028] Figure 3 This is a top view of another packaging structure provided in this utility model embodiment. Detailed Implementation

[0029] 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.

[0030] 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.

[0031] This utility model embodiment provides a packaging structure. Figure 1 This is a schematic diagram of a packaging structure provided in this utility model embodiment. 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 The packaging structure includes:

[0032] The packaged wafer 10, heat sink 20, molding compound 30, and external pins 40;

[0033] The heat sink 20 is disposed on one side of the wafer 10 to be packaged, the molding compound 30 covers the wafer 10 to be packaged and 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 to the molding compound 30.

[0034] External pin 40 is located on the side of the wafer 10 to be packaged away from the heat sink 20, and on the side of the molding compound 30 away from the wafer 10 to be packaged. External pin 40 is electrically connected to the wafer 10 to be packaged.

[0035] 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.

[0036] Specifically, during the manufacturing process, the heat sink 20 is first placed on the surface of the wafer 10 to be packaged, and then the molding compound 30 is made. The part of the surface of the heat sink 20 away from the wafer 10 to be packaged is exposed to the molding compound 30. That is, the molding compound 30 only covers a part of the surface of the molding compound 30 away from the wafer 10 to be packaged, 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 forming.

[0037] This embodiment of the invention provides a heat sink 20 on the side of the wafer 10 to be packaged that is away from the external pins 40. This allows the wafer 10 to dissipate heat through both the heat sink 20 and the external pins 40, achieving double-sided heat dissipation. Furthermore, the portion of the surface of the heat sink 20 away from the wafer 10 is exposed to expose the molding compound 30. This not only improves the heat dissipation effect of the heat sink 20 but also allows the molding compound 30 to cover a portion of the surface of the heat sink 10, resulting in a larger coverage area on the side where the heat sink 20 is located. This is more conducive to the molding of the molding compound 30 and makes the overall packaging structure more stable.

[0038] Based on the above embodiments, optionally, the heat sink 20 includes a thinning portion 22 and a protrusion 21, with the thinning portion 22 surrounding the protrusion 21; the surface of the protrusion 21 away from the wafer 10 to be packaged has a first distance D1 between it and the wafer 10 to be packaged, and the surface of the thinning portion 22 away from the wafer 10 to be packaged has a second distance D2 between it and the wafer 10 to be packaged, with the first distance D1 being greater than the second distance D2;

[0039] The molding compound 30 covers the thinned portion 22, and the protrusion 21 is away from the surface of the wafer 10 to be packaged, exposing the molding compound 30.

[0040] Specifically, the protrusion 21 protrudes outward relative to the thinning portion 22 on the side away from the wafer 10 to be packaged. The molding compound 30 covers the thinning portion 22, so that the molding compound 30 has a larger coverage area on the side of the heat sink 20 away from the wafer 10 to be packaged. This makes the molding compound 30 easier to form, makes the heat sink 20 more stable, and the surface of the protrusion 21 away from the wafer 10 to be packaged exposed by the molding compound 30 can better dissipate heat.

[0041] Based on the above embodiments, optionally, the surface of the molding layer 30 away from the external pin 40 is flush with the surface of the protrusion 21 away from the external pin 40.

[0042] This design makes the surface of the heat sink 20 in the encapsulation structure planar, resulting in a more regular shape, smaller size, and better structural stability for the entire plastic encapsulation structure.

[0043] Based on the above embodiments, optionally, the surface of the thinned portion 22 adjacent to the wafer 10 to be packaged is flush with the surface of the protrusion 21 adjacent to the wafer 10 to be packaged.

[0044] That is, the surface of the heat sink 20 adjacent to the wafer 10 to be packaged is flat. This setting allows the heat sink 20 to fit better with the wafer 10 to be packaged, so that the heat sink 20 can better conduct the heat generated by the wafer 10 to be packaged and improve the heat dissipation efficiency.

[0045] Based on the above embodiments, optionally, the ratio of the thickness of the thinned portion 22 to the thickness of the protrusion 21 is greater than or equal to 1 / 3 and less than or equal to 3 / 4.

[0046] Specifically, the protrusion 21 is the main heat dissipation part of the heat sink 20, and its thickness can be set according to heat dissipation requirements. The thinned part 22 is the thinnest part of the heat sink 20. If the thickness of the thinned part 22 is too thin, it will hinder heat conduction and affect the structural strength of the thinned part 22. If the thickness of the thinned part 22 is too thick, it will affect the thickness of the encapsulation layer 30 covering the thinned part 22, which will hinder the molding of the encapsulation layer 30. By setting the ratio of the thickness of the thinned part 22 to the thickness of the protrusion 21 to be greater than or equal to 1 / 3 and less than or equal to 3 / 4, the thickness of the thinned part 22 will not be too thin to affect the structural strength of the heat sink, and the thickness of the thinned part 22 will not be too thick to affect the molding of the encapsulation layer 30. For example, the ratio of the thickness of the thinned part 22 to the thickness of the protrusion 21 is 1 / 2.

[0047] Based on the above embodiments, optionally, the distance S between the edge of the thinned portion 22 away from the protrusion 21 and the edge of the thinned portion 22 adjacent to the protrusion 21 is greater than or equal to 100 micrometers.

[0048] That is, along the direction from the protrusion 21 to the thinning part 22, the width of the thinning part 22 is greater than or equal to 100 micrometers. This setting makes the area covered by the molding compound 30 of the heat sink 20 larger, avoiding the situation where the coverage area is too small and the molding compound 30 cannot be formed on the surface of the heat sink 20.

[0049] Based on the above embodiments, optionally, the distance L between the edge of the vertical projection of the molding compound 30 onto the surface of the wafer 10 adjacent to the heat sink 20 and the edge of the vertical projection of the heat sink 20 onto the surface of the wafer 10 adjacent to the heat sink 20 is greater than or equal to 100 micrometers.

[0050] The distance L between the side of the molding compound 30 and the side of the heat sink 20 is greater than or equal to 100 micrometers, which makes the part of the molding compound 30 covering the side of the heat sink 20 thicker, which is beneficial to the molding of the molding compound 30.

[0051] Based on the above embodiments, optionally, the heat sink 20 covers the wafer 10 to be packaged in the vertical projection of the wafer 10 to be packaged.

[0052] That is, the area of ​​the heat sink 20 is greater than or equal to the area of ​​the surface of the wafer 10 to be packaged adjacent to the heat sink 20, so that the heat sink 20 can better conduct the heat generated by the wafer 10 to be packaged and improve the heat dissipation speed.

[0053] Based on the above embodiments, optionally, a thermally conductive connection layer 50 is provided between the heat sink 20 and the wafer 10 to be packaged.

[0054] Specifically, the thermally conductive bonding layer 50 is used to bond the heat sink 20 to the wafer 10 to be packaged and to conduct heat. For example, the thermally conductive bonding layer 50 can be a thermally conductive adhesive, etc. By providing the thermally conductive bonding layer 50, the heat sink 20 and the wafer 10 to be packaged can be stably connected, and there is a faster heat conduction speed between the wafer 10 to be packaged and the heat sink 20, resulting in a faster heat dissipation speed for the packaged structure.

[0055] Figure 3 This is a top view of another packaging structure provided by an embodiment of the present invention. Optionally, based on the above embodiments, refer to... Figure 3 The external pins include a first external pin 41, a second external pin 42, and a third external pin 43;

[0056] 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 421 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.

[0057] 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.

[0058] 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.

[0059] 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.

[0060] 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.

[0061] 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.

[0062] 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.

[0063] 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.

[0064] 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.

[0065] 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 package structure, characterized by, include: Wafer to be packaged, heat sink, molding compound, and external pins; The heat sink is disposed on one side of the wafer to be packaged, the molding compound covers the wafer to be packaged and the heat sink, and a portion of the heat sink away from the surface of the wafer to be packaged is exposed by the molding compound. The external pin is located on the side of the wafer to be packaged away from the heat sink, and on the side of the molding layer away from the wafer to be packaged. The external pin is electrically connected to the wafer to be packaged.

2. The packaging structure according to claim 1, characterized in that: The heat sink includes a thinned portion and a protrusion, the thinned portion surrounding the protrusion; the protrusion has a first distance from the surface of the wafer to be packaged away from the wafer to be packaged, and the thinned portion has a second distance from the surface of the wafer to be packaged away from the wafer to be packaged, the first distance being greater than the second distance; The molding compound covers the thinned portion, and the protrusion is exposed away from the surface of the wafer to be packaged, thus exposing the molding compound.

3. The packaging structure according to claim 2, characterized in that: The surface of the molding layer away from the external pin is flush with the surface of the protrusion away from the external pin.

4. The packaging structure according to claim 2, characterized in that: The thinned portion is flush with the surface of the wafer to be packaged adjacent to the surface of the protrusion.

5. The packaging structure according to claim 2, characterized in that: The ratio of the thickness of the thinned portion to the thickness of the protrusion is greater than or equal to 1 / 3 and less than or equal to 3 / 4.

6. The packaging structure according to claim 2, characterized in that: The distance between the edge of the thinned portion away from the protrusion and the edge of the thinned portion adjacent to the protrusion is greater than or equal to 100 micrometers.

7. The packaging structure according to claim 1, characterized in that: The distance between the edge of the molding compound's vertical projection onto the surface of the wafer to be packaged adjacent to the heat sink and the edge of the heat sink's vertical projection onto the surface of the wafer to be packaged adjacent to the heat sink is greater than or equal to 100 micrometers.

8. The packaging structure according to claim 1, characterized in that: The heat sink covers the wafer to be packaged in a vertical projection. A thermally conductive connection layer is provided between the heat sink and the wafer to be packaged.

9. 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.

10. The packaging structure according to claim 9, characterized in that: The plurality of first insert fingers include a first edge insert finger, and the plurality of second insert fingers include a second edge insert finger; The other first insert finger portions, excluding the first edge insert finger portion, and the other second insert finger portions, excluding the second edge insert finger portion, are located between the first edge insert finger portion and the second edge insert finger portion along the first direction; The width of the first edge insertion portion and the second edge insertion portion along the first direction is greater than the width of the other first insertion portions along the first direction, and is greater than the width of the other second insertion portions along the first direction.

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