Heat dissipation cover, chip packaging structure and forming method thereof

Abstract

The invention relates to a heat dissipation cover, a chip packaging structure and a forming method thereof. The heat dissipation cover comprises a supporting shell, the supporting shell comprises a body part and a boss arranged on the lower surface of the body part in a protruding mode, the body part comprises an upper surface and the lower surface which are oppositely distributed, and the boss comprises a top face facing the body part and a bottom face opposite to the top face; the area of the upper surface of the body part is larger than that of the bottom surface of the boss, and the bottom surface of the boss is used for covering a chip; and the supporting column is connected to the end part of the body part and extends along the direction perpendicular to the upper surface of the body part, and the supporting column is used for being connected with a lead frame. The heat dissipation effect of the chip packaging structure can be improved, the influence of the external environment can be effectively reduced, and self warping can be inhibited.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor manufacturing technology, and in particular to a heat dissipation cover, a chip packaging structure and a forming method thereof. Background Art

[0002] Currently, there are two primary heat dissipation pathways for frame-type package products: one is downward heat conduction along the path from the heat source surface to the chip, then to the base island, and finally to the PCB; the other is upward heat conduction along the path from the heat source surface to the plastic layer. The presence of bonding wires electrically connecting the chip to the pins in the lead frame prevents the plastic layer above the heat source surface from being too thin. Furthermore, the thermal conductivity of commonly used plastic materials is relatively low (e.g., only around 0.96 W / (m·K)), resulting in less heat transfer from above the heat source surface.

[0003] Currently, the main method to improve the heat dissipation performance of the packaging structure is to reduce thermal resistance. There are three main methods to improve the heat dissipation performance of the chip by reducing thermal resistance: (1) increasing the thermal conductivity of the material; (2) shortening the heat transfer path; and (3) increasing the heat dissipation area. In the current packaging structure, the heat transfer area of ​​the chip is mainly the active surface area of ​​the chip. Considering the wafer production cost, it is generally not possible to reduce the thermal resistance by increasing the chip area. At the same time, the thermal conductivity of the plastic layer currently produced in mass production can only reach about 3.1W / (m·K) at most. Not only does it not significantly improve the heat dissipation effect, but it is also prone to problems such as excessive warping. Because the chip packaging structure is equipped with bonding wires inside, there are strict restrictions on the thickness of the plastic layer above the chip, and it cannot be made thinner.

[0004] Therefore, how to improve the heat dissipation effect of the chip in the chip packaging structure while reducing the warping of the chip packaging structure to ensure the performance and yield of the chip packaging structure is a technical problem that needs to be solved urgently. Summary of the Invention

[0005] The present invention provides a heat dissipation cover, a chip packaging structure and a forming method thereof, which are used to improve the heat dissipation effect of the chip in the chip packaging structure while reducing the warping of the chip packaging structure, thereby ensuring the performance and yield of the chip packaging structure.

[0006] According to some embodiments, the present invention provides a heat dissipation cover, comprising:

[0007] A support housing, comprising a main body and a boss protruding from the lower surface of the main body, wherein the main body comprises an upper surface and a lower surface that are relatively distributed, and the boss comprises a top surface facing the main body and a bottom surface opposite to the top surface, wherein the area of ​​the upper surface of the main body is larger than the area of ​​the bottom surface of the boss, and the bottom surface of the boss is used for mounting on a chip;

[0008] A support column is connected to an end of the main body and extends in a direction perpendicular to the upper surface of the main body, and is used to be connected to a lead frame.

[0009] In some embodiments, further comprising:

[0010] A vacuum containing chamber, located inside the supporting shell;

[0011] a capillary structure layer, located on the inner wall of the vacuum containing chamber;

[0012] The cooling liquid is located in the vacuum containing chamber.

[0013] In some embodiments, the cooling liquid occupies 30% to 40% of the volume of the vacuum chamber.

[0014] In some embodiments, the vacuum chamber is located only within the boss; or

[0015] The vacuum containing chambers are continuously distributed in the boss and the main body.

[0016] In some embodiments, the support shell is a solid shell.

[0017] In some embodiments, further comprising:

[0018] A plurality of heat dissipation fins are located on the upper surface of the main body.

[0019] In some embodiments, a plurality of the heat dissipation fins are arranged in a staggered manner and spaced apart on the upper surface of the main body.

[0020] In some embodiments, the lower surface of the main body includes a middle portion and an avoidance portion located on the outer periphery of the middle portion, and the boss is provided on the middle portion.

[0021] In some embodiments, the cross-section of the main body is an inverted cone, the avoidance portion forms an inverted cone wall, and the cross-section of the boss is a rectangle.

[0022] In some embodiments, a groove is formed on the avoidance portion.

[0023] In some embodiments, there are multiple support pillars, and the support pillars are symmetrically distributed around the periphery of the boss.

[0024] In some embodiments, the upper surface of the main body is rectangular, and the four support columns are distributed in a one-to-one correspondence at the four corners of the rectangular main body.

[0025] In some embodiments, the support shell is made of metal.

[0026] According to some other embodiments, the present invention further provides a chip packaging structure, including:

[0027] Chip, including the front and back sides that are relatively distributed;

[0028] a lead frame, the chip being mounted on the lead frame with the back surface of the chip facing the lead frame;

[0029] A heat dissipation cover includes a support shell and a support column, wherein the support shell includes a main body and a boss protruding from the lower surface of the main body, the main body includes an upper surface and a lower surface that are relatively distributed, the boss includes a top surface facing the main body and a bottom surface opposite to the top surface, and the area of ​​the upper surface of the main body is larger than the area of ​​the bottom surface of the boss, the bottom surface of the boss is mounted on the front side of the chip, the support column extends in a direction perpendicular to the upper surface of the main body, one end of the support column is connected to the end of the main body, and the other end is connected to the lead frame.

[0030] In some embodiments, the front surface of the chip includes a heat dissipation area and a functional area arranged around the periphery of the heat dissipation area, and a plurality of metal contacts are arranged in the functional area;

[0031] The bottom surface of the boss is mounted on the heat dissipation area, and the area of ​​the bottom surface of the boss is smaller than the area of ​​the heat dissipation area.

[0032] In some embodiments, the heat dissipation cover further comprises:

[0033] A vacuum containing chamber, located inside the supporting shell;

[0034] a capillary structure layer, located on the inner wall of the vacuum containing chamber;

[0035] The cooling liquid is located in the vacuum containing chamber.

[0036] In some embodiments, the cooling liquid occupies 30% to 40% of the volume of the vacuum chamber.

[0037] In some embodiments, the vacuum chamber is located only within the boss; or

[0038] The vacuum containing chambers are continuously distributed in the boss and the main body.

[0039] In some embodiments, further comprising:

[0040] A circuit board, wherein the lead frame is located above the circuit board;

[0041] An external radiator is mounted on the upper surface of the main body, and a fixing piece is provided at the end of the external radiator, one end of the fixing piece is connected to the external radiator, and the other end is connected to the circuit board.

[0042] In some embodiments, the support shell is a solid shell.

[0043] In some embodiments, the heat dissipation cover further comprises:

[0044] A plurality of heat dissipation fins are located on the upper surface of the main body.

[0045] In some embodiments, the lower surface of the main body includes a middle portion and an avoidance portion located on the outer periphery of the middle portion, and the boss is provided on the middle portion.

[0046] In some embodiments, the cross-section of the main body is an inverted cone, the avoidance portion forms an inverted cone wall, and the cross-section of the boss is a rectangle.

[0047] In some embodiments, the lead frame includes a base island and pins distributed around the periphery of the base island, and the chip is mounted on the base island;

[0048] The chip packaging structure also includes a bonding wire, one end of which is electrically connected to the front surface of the chip and the other end is electrically connected to the pin. The vertical distance between the avoidance portion of the main body and the bonding wire is 10 microns to 30 microns.

[0049] In some embodiments, a groove is formed on the avoidance portion at a position corresponding to the bonding wire.

[0050] In some embodiments, further comprising:

[0051] An insulating adhesive film is provided between the boss and the chip and is used for adhering the heat dissipation cover to the chip.

[0052] In some embodiments, further comprising:

[0053] A circuit board, wherein the lead frame is located above the circuit board;

[0054] A plastic encapsulation layer is located above the circuit board, and the plastic encapsulation layer encapsulates the lead frame and the chip. One end of the pin away from the base island is exposed to the outside of the plastic encapsulation layer, and the other end of the pin away from the base island is electrically connected to the upper surface of the circuit board.

[0055] In some embodiments, the lead frame further includes a base island extension portion, wherein the base island extension portion is connected to an end portion of the base island and extends out of the plastic encapsulation layer;

[0056] One end of the support column is connected to the end of the main body, and the other end is connected to the base island extension.

[0057] In some embodiments, the plurality of support columns are symmetrically distributed around the periphery of the boss, and the plurality of base island extensions connected to the plurality of support columns in a one-to-one correspondence are symmetrically distributed around the periphery of the base island.

[0058] In some embodiments, the support shell is made of metal.

[0059] According to some further embodiments, the present invention further provides a method for forming a chip packaging structure, comprising the following steps:

[0060] A heat dissipation cover is formed, the heat dissipation cover comprising a support shell and a support column, the support shell comprising a main body and a boss protruding from a lower surface of the main body, the main body comprising an upper surface and a lower surface that are oppositely distributed, the boss comprising a top surface facing the main body and a bottom surface opposite to the top surface, wherein the area of ​​the upper surface of the main body is larger than the area of ​​the bottom surface of the boss, and the support column is connected to an end of the main body and extends in a direction perpendicular to the upper surface of the main body;

[0061] Mounting a chip on a lead frame, wherein the chip includes a front side and a back side that are relatively distributed, and the back side of the chip faces the lead frame;

[0062] The heat dissipation cover is mounted on the front surface of the chip along the bottom surface of the boss toward the front surface of the chip, and the support column and the lead frame are connected.

[0063] In some embodiments, the specific steps of mounting the chip onto the lead frame include:

[0064] forming the lead frame, wherein the lead frame includes a base island, pins distributed around the periphery of the base island, and a base island extension connected to an end of the base island;

[0065] Mounting the chip on the base island along the back side of the chip toward the base island;

[0066] A bonding wire is formed with one end electrically connected to the front surface of the chip and the other end electrically connected to the pin.

[0067] In some embodiments, the specific steps of connecting the support pillar and the lead frame include:

[0068] The supporting column is connected to the base island extension portion.

[0069] In some embodiments, after attaching the heat dissipation cover to the front surface of the chip along the bottom surface of the boss toward the front surface of the chip and connecting the support pillars to the lead frame, the following steps are further included:

[0070] A plastic packaging layer for packaging the base island, the pins and the chip is formed below the heat dissipation cover, and one end of the pin away from the base island, the base island extension and the support column are exposed outside the plastic packaging layer.

[0071] The present invention provides a heat dissipation cover, a chip packaging structure, and a method for forming the same. The heat dissipation cover comprises a support housing and support columns disposed within the heat dissipation cover. The support housing comprises a main body and a boss protruding from the lower surface of the main body. The main body comprises an upper surface and a lower surface disposed opposite each other. The boss comprises a top surface facing the main body and a bottom surface opposite the top surface. The area of ​​the upper surface of the main body is greater than the area of ​​the bottom surface of the boss. The bottom surface of the boss is configured to cover the chip, thereby extending the heat source surface from the front surface of the chip to the entire surface of the package. This significantly increases the heat dissipation area of ​​the chip packaging structure and improves the heat dissipation effect of the chip within the chip packaging structure. Furthermore, because the boss protrudes from the lower surface of the main body, sufficient space is left for bonding wires through the relief between the outer wall of the boss and the lower surface of the main body. This prevents contact between the heat dissipation cover and the bonding wires, which could cause chip packaging structure abnormalities (e.g., short circuits between the heat dissipation cover and the bonding wires), thereby ensuring the stability of the chip packaging structure. The bosses also expand the heat dissipation surface, quickly transferring heat generated by the chip to the package surface. Furthermore, the support shell is made of metal, which has better Young's modulus and coefficient of thermal expansion (CTE), thereby further improving the warping problem of the chip package structure.

[0072] At the same time, by providing support columns at the ends of the support housing for connection to the lead frame, a clamping force is generated through the connection between the support columns and the lead frame, reducing or even suppressing warping of the lead frame and the entire package. Furthermore, the provision of the support columns can provide more support for the heat dissipation cover when attaching an external heat sink, ensuring that the chip is not affected by the external heat sink during installation. BRIEF DESCRIPTION OF THE DRAWINGS

[0073] To more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly describes the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention, and those skilled in the art can derive other drawings based on these drawings without inventive effort.

[0074] Figure 1 is a schematic cross-sectional view of a heat dissipation cover in a specific embodiment of the present invention;

[0075] Figure 2 is a schematic top view of a heat dissipation cover in a specific embodiment of the present invention;

[0076] Figure 3 is another cross-sectional schematic diagram of the heat dissipation cover in a specific embodiment of the present invention;

[0077] Figure 4 is another cross-sectional schematic diagram of the heat dissipation cover in a specific embodiment of the present invention;

[0078] Figure 5 This is a schematic diagram of the arrangement of heat dissipation ribs in a specific embodiment of the present invention;

[0079] Figure 6 is a schematic cross-sectional view of a chip packaging structure in a specific embodiment of the present invention;

[0080] Figure 7 Schematic diagram of the relative positional relationship between the heat dissipation cover, the chip and the lead frame in a specific embodiment of the present invention;

[0081] Figure 8 It is a schematic diagram of a partial structure of a lead frame in a specific embodiment of the present invention;

[0082] Figure 9 is an exploded schematic diagram of a chip packaging structure in a specific embodiment of the present invention;

[0083] Figure 10 This is a schematic diagram of a three-dimensional structure of a chip packaging structure in a specific embodiment of the present invention;

[0084] Figure 11 is a cross-sectional schematic diagram of a specific embodiment of the present invention after an external radiator is mounted on the heat dissipation cover;

[0085] Figure 12 is another cross-sectional schematic diagram of the chip packaging structure in a specific embodiment of the present invention;

[0086] Figure 13 is another structural schematic diagram of the support shell in a specific embodiment of the present invention;

[0087] Figure 14is another cross-sectional schematic diagram of a chip packaging structure in a specific embodiment of the present invention;

[0088] Figure 15 It is a flow chart of a method for forming a chip packaging structure in a specific embodiment of the present invention. DETAILED DESCRIPTION

[0089] The specific embodiments of the heat dissipation cover, chip packaging structure and forming method thereof provided by the present invention are described in detail below with reference to the accompanying drawings.

[0090] This specific embodiment provides a heat dissipation cover, Figure 1 is a cross-sectional schematic diagram of a heat dissipation cover in a specific embodiment of the present invention, Figure 2 FIG. 1 is a top view of a heat dissipation cover in a specific embodiment of the present invention. Figure 1 and Figure 2 As shown, the heat dissipation cover includes:

[0091] A support housing includes a main body 10 and a boss 11 protruding from the lower surface of the main body 10. The main body 10 includes an upper surface 101 and a lower surface that are relatively distributed. The boss 11 includes a top surface facing the main body 10 and a bottom surface 111 opposite to the top surface. The area of ​​the upper surface 101 of the main body 10 is larger than the area of ​​the bottom surface 111 of the boss 11. The bottom surface 111 of the boss 11 is used for mounting on a chip.

[0092] The support column 12 is connected to the end of the main body 10 and extends in a direction perpendicular to the upper surface 101 of the main body 10 . The support column 12 is used to connect to the lead frame.

[0093] Specifically, the supporting shell includes the main body 10, and the main body 10 includes the upper surface 101 and the lower surface that are relatively distributed. The upper surface 101 of the main body 10 is used for heat exchange with the surrounding environment or for carrying an external radiator and performing heat exchange with the external radiator. The boss 11 is arranged on the lower surface of the main body 10, and the boss 11 protrudes in the direction away from the upper surface 101 of the main body 10 relative to the lower surface of the main body 10 (that is, the boss 11 protrudes downward relative to the main body 10). The boss 11 includes the top surface facing the main body 10 and the bottom surface 111 away from the main body 10, and the bottom surface 111 of the boss 11 is used for mounting on the front side of a chip. Since the area of ​​the upper surface 101 of the main body 10 is larger than the area of ​​the bottom surface 111 of the boss 11, and the bottom surface 111 of the boss 11 is used to cover the front surface of the chip, the heat source surface can be extended from the front surface of the chip to the surface of the entire package body, thereby significantly increasing the heat dissipation area of ​​the chip packaging structure and improving the heat dissipation effect of the chip in the chip packaging structure. Moreover, since the boss 11 is protruding from the lower surface of the main body 10, the groove formed by the outer wall of the boss 11 and the outer peripheral side of the lower surface of the main body 10 can leave sufficient space for the bonding wire (the bonding wire is used to electrically connect the chip to the pins in the lead frame), avoiding the chip packaging structure abnormality caused by the contact between the heat dissipation cover and the bonding wire (such as the short circuit problem between the heat dissipation cover and the bonding wire), thereby ensuring the stability of the chip packaging structure performance. The area of ​​the upper surface 101 of the main body 10 is larger than the area of ​​the bottom surface 111 of the boss 11, thereby increasing the area of ​​the heat dissipation cover for heat exchange with the external environment or an external radiator (i.e., increasing the heat dissipation surface of the heat dissipation cover), thereby further improving the heat dissipation efficiency and heat dissipation effect.

[0094] In this specific embodiment, the support column 12 is provided at the end of the support shell, and the support column 12 extends in a direction perpendicular to the upper surface 101 of the main body 10, so that the heat dissipation cover and the lead frame can be fixedly connected through the support column 12. On the one hand, a clamping force can be formed by the connection between the support column 12 and the lead frame, thereby reducing or even suppressing the warping of the lead frame and the entire package body; on the other hand, the provision of the support column 12 can provide more support for the heat dissipation cover when mounting an external radiator, thereby ensuring that the chip is not affected when the external radiator is installed.

[0095] In some embodiments, as Figure 1 and Figure 2 As shown, the heat dissipation cover further includes:

[0096] A vacuum housing chamber 13 is located inside the supporting shell;

[0097] a capillary structure layer, located on the inner wall of the vacuum containing chamber;

[0098] The cooling liquid 14 is located in the vacuum chamber 13 .

[0099] In some embodiments, the cooling liquid 14 occupies 30% to 40% of the volume of the vacuum chamber 13 to improve the vaporization efficiency of the cooling liquid 14 .

[0100] In some embodiments, the vacuum chamber 13 is located only in the boss 11; or

[0101] The vacuum containing chambers 13 are continuously distributed in the boss 11 and the main body 10 .

[0102] For example, if Figure 1 and Figure 2 As shown, the heat dissipation cover includes the vacuum chamber 13 continuously distributed in the boss 11 and the main body 10, the capillary structure layer distributed on the inner wall of the vacuum chamber 13 (including the side wall and bottom wall of the vacuum chamber 13), and the coolant filled in the vacuum chamber 13, that is, the supporting shell is a hollow shell. In one example, the coolant 14 can be deionized water or alcohol. For example, the capillary structure layer is a porous capillary structure formed on the inner wall of the vacuum chamber 13 by a high-temperature sintering process using copper powder as raw material. By controlling the copper powder particle size and the sintering temperature, the porosity and permeability of the porous capillary structure can be adjusted to achieve efficient liquid (i.e., the coolant) reflux capability.

[0103] After the heat dissipation cover is attached to the front of the chip, the heat generated by the chip during operation will be transferred to the coolant in the vacuum chamber 13 through the boss 11. In a vacuum environment, the boiling point of the coolant 14 is low, so the coolant 14 in the vacuum chamber 13 will vaporize to form a gas or a gas-liquid mixture after absorbing the heat of the chip product. The gas or gas-liquid mixture will rise along the capillary structure layer. In the process of rising along the capillary structure layer or after reaching the top of the vacuum chamber 13, the gas or gas-liquid mixture will exchange heat with the surrounding environment with a lower temperature or an external radiator and re-liquefy to form the coolant 14. The re-liquefied coolant 14 flows back to the bottom of the vacuum chamber 13 under the combined action of gravity and capillary force, thereby achieving cyclic heat dissipation of the chip through the phase change of the coolant 14.

[0104] By forming the vacuum chamber 13 within the support shell and disposing the capillary structure layer and the coolant 14 within the vacuum chamber 13, the entire support shell, the capillary structure layer, and the coolant 14 together form a heat spreader. The heat transfer coefficient of the heat spreader, both in terms of thermal conductivity and transient response efficiency, is tens or even hundreds of times higher than that of pure copper. This lowers the thermal resistance of the package located below the heat dissipation cover, greatly improving the heat dissipation performance of the chip and the package. The heat dissipation cover having the vacuum chamber 13, the capillary structure layer, and the coolant 14 is suitable for large-scale, high-power frame-type packaging products. Because large-scale, high-power frame-type packaging products cannot rely on their own heat dissipation area to ensure the normal operation of the chip, an external heat dissipation structure such as an external radiator needs to be provided on the heat dissipation cover to ensure the normal operation of the chip. The arrangement of the vacuum chamber, the capillary structure layer and the coolant 14 enables the heat dissipation cover to have a higher heat transfer response efficiency, thereby being able to transfer the heat in the chip and the package body to the external heat dissipation structure such as the external radiator in a timely manner, thereby ensuring the normal operation of the chip.

[0105] Figure 3 FIG. 2 is another cross-sectional schematic diagram of the heat dissipation cover in a specific embodiment of the present invention. In other embodiments, the support shell is a solid shell.

[0106] For example, for small-sized, low-power frame-type packaging products, even if there is no external heat dissipation structure such as an external radiator, the normal operation of the chip can be ensured by relying on the heat dissipation of the heat dissipation cover. Therefore, in order to reduce the heat dissipation cost and simplify the structure and manufacturing process of the heat dissipation cover, the support shell in the heat dissipation cover can be set to a solid shell, and the heat is conducted by relying on the support shell itself, that is, the heat generated by the chip and the package body can be transmitted to the outside through the solid support shell.

[0107] Figure 4 is another cross-sectional schematic diagram of the heat dissipation cover in a specific embodiment of the present invention, Figure 5 Schematic diagram of the arrangement of heat dissipation ribs in a specific embodiment of the present invention. Figure 4 and Figure 5 As shown, the heat dissipation cover further includes:

[0108] A plurality of heat dissipation fins 40 are located on the upper surface 101 of the main body 10 .

[0109] In some embodiments, the plurality of heat dissipation fins 40 are arranged on the upper surface 101 of the main body 10 in a staggered manner. Figure 5 shown.

[0110] For example, the upper surface 101 of the main body 10 is provided with a plurality of heat dissipation fins 40 arranged in a direction parallel to the upper surface 101 of the main body 10. For small-sized, low-power frame-type package products, the heat dissipation fins 40 can also be used for air cooling, thereby further enhancing the heat dissipation effect of the package product. The plurality of heat dissipation fins 40 are arranged in a staggered manner on the upper surface 101 of the main body 10, meaning that the plurality of heat dissipation fins 40 are arranged in a staggered manner on the upper surface 101 of the main body 10 along the X-axis and Y-axis directions, with adjacent rows of heat dissipation fins 40 staggered along the Y-axis. By arranging the plurality of heat dissipation fins 40 in a staggered manner on the upper surface 101 of the main body 10, the package body not only increases its heat dissipation area under forced air cooling but also more easily forms turbulent flow between adjacent heat dissipation fins 40, continuously destroying the thermal boundary layer formed on the surface, which is more conducive to heat dissipation than a laminar flow mode. The "plurality" in this embodiment refers to more than two. The X-axis direction and the Y-axis direction are both parallel to the upper surface 101 of the main body 10, and the X-axis direction intersects the Y-axis direction perpendicularly.

[0111] In some embodiments, the lower surface of the main body 10 includes a middle portion and a relief portion 102 located on the outer periphery of the middle portion, and the boss 11 is provided on the middle portion.

[0112] In some embodiments, the cross section of the main body 10 is in the shape of an inverted cone, the avoidance portion 102 forms an inverted cone wall, and the cross section of the boss 11 is rectangular.

[0113] In some embodiments, a groove is formed on the avoidance portion 102 .

[0114] Specifically, the cross-section of the boss 11 is rectangular, making it easier to attach to the front surface of the chip. The cross-section of the main body 10 is an inverted cone, and the avoidance portion 102 forms an inverted cone wall. The avoidance portion 102 is formed with the groove. On the one hand, it can provide more space for the bonding wires in the package structure, thereby further ensuring the isolation between the supporting housing and the bonding wires; on the other hand, the coolant circulation channel is shorter, and the heat dissipation efficiency is higher.

[0115] In some embodiments, there are multiple support pillars 12 , and the support pillars 12 are symmetrically distributed around the periphery of the boss 11 .

[0116] In some embodiments, the upper surface 101 of the main body 10 is rectangular, and the four support columns 12 are distributed at the four corners of the rectangular main body 10 in a one-to-one correspondence.

[0117] For example, if Figure 1 and Figure 2 As shown, the four support columns 12 are distributed one-to-one at the four corners of the rectangular main body 10. This allows for a uniformly distributed clamping force between the four support columns 12 and the lead frame, thereby effectively suppressing package warping. Furthermore, when an external heat sink is connected to the heat dissipation cover, the symmetrically distributed support columns 12 can disperse the pressure applied by the external heat sink to the heat dissipation cover, ensuring that the chip beneath the support housing is not affected.

[0118] In some embodiments, the support shell is made of metal.

[0119] Specifically, the support housing is made of metal, not only because it has excellent thermal conductivity, allowing it to more quickly transfer heat generated by the chip to the outside world, but also because it exhibits superior performance in parameters such as thermal expansion coefficient and Young's modulus, significantly reducing package warpage. In one example, the support housing is made of copper.

[0120] This specific embodiment also provides a chip packaging structure, Figure 6 is a schematic cross-sectional view of a chip packaging structure in a specific embodiment of the present invention. The schematic diagram of the heat dissipation cover in the chip packaging structure can be seen in FIG. Figure 1-Figure 5 .like Figure 1 、 Figure 2 and Figure 6 As shown, the chip packaging structure includes:

[0121] Chip 60, including a front side and a back side that are relatively distributed;

[0122] a lead frame, the chip 60 is mounted on the lead frame, with the back surface of the chip 60 facing the lead frame;

[0123] The heat dissipation cover includes a supporting shell and a supporting column 12. The supporting shell includes a main body 10 and a boss 11 protruding from the lower surface of the main body 10. The main body 10 includes an upper surface 101 and a lower surface that are relatively distributed. The boss 11 includes a top surface facing the main body 10 and a bottom surface 111 opposite to the top surface. The area of ​​the upper surface 101 of the main body 10 is larger than the area of ​​the bottom surface 111 of the boss 11. The bottom surface 111 of the boss 11 is mounted on the front of the chip 60. The supporting column 12 extends in a direction perpendicular to the upper surface 101 of the main body 10. One end of the support column 12 is connected to the end of the main body 10 and the other end is connected to the lead frame.

[0124] Specifically, if Figure 1 、 Figure 2 and Figure 6 As shown, the chip 60 includes a front side and a back side that are relatively distributed. The chip 60 is mounted on the lead frame with the back side facing the lead frame and is electrically connected to the lead frame. The supporting shell in the heat dissipation cover includes the main body 10 and the boss 11. The upper surface 101 of the main body 10 is used for heat exchange with the surrounding environment or for carrying an external radiator and performing heat exchange with the external radiator. The boss 11 is arranged on the lower surface of the main body 10, and the boss 11 protrudes in a direction away from the upper surface 101 of the main body 10 relative to the lower surface of the main body 10 (that is, the boss 11 protrudes downward relative to the main body 10). The boss 11 includes the top surface facing the main body 10 and the bottom surface 111 away from the main body 10, and the bottom surface 111 of the boss 11 is mounted on the front side of the chip 60. Since the area of ​​the upper surface 101 of the main body 10 is larger than the area of ​​the bottom surface 111 of the boss 11, and the bottom surface 111 of the boss 11 is used to cover the front surface of the chip, the heat source surface can be extended from the front surface of the chip to the surface of the entire package body, thereby significantly increasing the heat dissipation area of ​​the chip packaging structure and improving the heat dissipation effect of the chip in the chip packaging structure. Moreover, since the boss 11 is protruding from the lower surface of the main body 10, the groove formed by the outer wall of the boss 11 and the outer peripheral side of the lower surface of the main body 10 can leave sufficient space for the bonding wire (the bonding wire is used to electrically connect the chip to the pins in the lead frame), avoiding the chip packaging structure abnormality caused by the contact between the heat dissipation cover and the bonding wire (such as the short circuit problem between the heat dissipation cover and the bonding wire), thereby ensuring the stability of the chip packaging structure performance. The area of ​​the upper surface 101 of the main body 10 is larger than the area of ​​the bottom surface 111 of the boss 11, thereby increasing the area of ​​the heat dissipation cover for heat exchange with the external environment or an external radiator (i.e., increasing the heat dissipation surface of the heat dissipation cover), thereby further improving the heat dissipation efficiency and heat dissipation effect.

[0125] In this specific embodiment, the support column 12 is provided at the end of the support shell, and the support column 12 extends in a direction perpendicular to the upper surface 101 of the main body 10, so that the heat dissipation cover and the lead frame can be fixedly connected through the support column 12. On the one hand, a clamping force can be formed by the connection between the support column 12 and the lead frame, thereby reducing or even suppressing the warping of the lead frame and the entire package body; on the other hand, the provision of the support column 12 can provide more support for the heat dissipation cover when mounting an external radiator, thereby ensuring that the chip is not affected when the external radiator is installed.

[0126] Figure 7 Schematic diagram of the relative position relationship between the heat dissipation cover, the chip and the lead frame in a specific embodiment of the present invention. Figure 9 is an exploded schematic diagram of a chip packaging structure in a specific embodiment of the present invention, Figure 10 Schematic diagram of a three-dimensional structure of a chip packaging structure in a specific embodiment of the present invention. In some embodiments, the front surface of the chip 60 includes a heat dissipation area and a functional area arranged around the periphery of the heat dissipation area, and a plurality of metal contacts 71 are arranged in the functional area;

[0127] The bottom surface 111 of the boss 11 is mounted on the heat dissipation area, and the area of ​​the bottom surface 111 of the boss 11 is smaller than the area of ​​the heat dissipation area.

[0128] For example, if Figure 6 、 Figure 7 、 Figure 9 and Figure 10 As shown, the front surface of the chip 60 includes the heat dissipation area and the functional area arranged around the periphery of the heat dissipation area. A plurality of metal contacts 71 are distributed in the functional area. The metal contacts 71 are used to lead signals from the chip 60 or transmit control signals to the chip 60. The bottom surface 111 of the boss 11 is mounted on the heat dissipation area, and the area of ​​the bottom surface 111 of the boss 11 is smaller than that of the heat dissipation area, thereby preventing the boss 11 from contacting the metal contacts 71 and causing a short circuit.

[0129] In some embodiments, as Figure 1 、 Figure 2 and Figure 6 As shown, the heat dissipation cover further includes:

[0130] A vacuum housing chamber 13 is located inside the supporting shell;

[0131] A capillary structure layer is located on the inner wall of the vacuum housing chamber 13;

[0132] The cooling liquid 14 is located in the vacuum chamber 13 .

[0133] In some embodiments, the cooling liquid 14 occupies 30% to 40% of the volume of the vacuum chamber 13 .

[0134] In some embodiments, the vacuum chamber 13 is located only in the boss 11; or

[0135] The vacuum containing chambers 13 are continuously distributed in the boss 11 and the main body 10 .

[0136] For example, if Figure 1 、 Figure 2 and Figure 6 As shown, after the heat dissipation cover is attached to the front surface of the chip 60, a portion of the heat generated by the chip 60 during operation is transferred through the boss 11 to the coolant within the vacuum chamber 13. In a vacuum environment, the coolant 14 has a low boiling point. Therefore, after absorbing the heat from the chip product, the coolant 14 within the vacuum capillary heat pipe vaporizes to form a gas or a gas-liquid mixture. This gas or gas-liquid mixture rises along the capillary structure layer. During this rise, or after reaching the top of the vacuum chamber 13, the gas or gas-liquid mixture exchanges heat with the cooler ambient temperature or an external heat sink, re-liquefying to form the coolant 14. The re-liquefied coolant 14 then flows back to the bottom of the vacuum chamber 13 under the combined effects of gravity and capillary forces, thereby achieving cyclical heat dissipation for the chip through phase change of the coolant 14. Another portion of the heat generated by the chip 60 can also be transferred downward to the outside world via the heat sink 67 below the lead frame.

[0137] By utilizing the entire supporting shell, the capillary structure layer and the coolant 14 to form a heat spreader, the heat transfer coefficient of the heat spreader, whether in terms of thermal conductivity or transient response efficiency, is tens or even hundreds of times higher than that of pure copper material, thereby making the thermal resistance of the package body located under the heat dissipation cover lower, greatly improving the heat dissipation performance of the chip 60 and the package body. The heat dissipation cover having the vacuum chamber 13, the capillary structure layer and the coolant 14 is suitable for large-sized, high-power frame-type packaging products, because large-sized, high-power frame-type packaging products cannot rely on their own heat dissipation area to ensure the normal operation of the chip. In order to ensure the normal operation of the chip, an external heat dissipation structure such as an external radiator needs to be provided on the heat dissipation cover. The provision of the vacuum chamber, the capillary structure layer and the coolant 14 enables the heat dissipation cover to have a higher heat transfer response efficiency, thereby being able to transfer the heat in the chip and the package body to the external heat dissipation structure such as the external radiator in a timely manner, thereby ensuring the normal operation of the chip.

[0138] Figure 11 : is a cross-sectional view of a specific embodiment of the present invention after an external heat sink is mounted on the heat dissipation cover. In some embodiments, Figure 1 、 Figure 2 、 Figure 6 and Figure 11 As shown, the chip packaging structure further includes:

[0139] A circuit board 66 , wherein the lead frame is located above the circuit board 66 ;

[0140] The external radiator 110 is mounted on the upper surface 101 of the main body 10 , and a fixing member 111 is provided at the end of the external radiator 110 . One end of the fixing member 111 is connected to the external radiator 110 , and the other end is connected to the circuit board 66 .

[0141] For example, if Figure 1 、 Figure 2 、 Figure 6 and Figure 11As shown, the chip package structure also includes a circuit board 66, heat dissipation vias 68 extending through the circuit board 66, and a heat sink 67 mounted on a surface of the circuit board 66. The lead frame is mounted on a surface of the heat sink 67 facing away from the circuit board 66, and the chip 60 is mounted on a surface of the lead frame facing away from the heat sink 67. In one example, the circuit board 66 may be a PCB. Heat generated by the chip 60 during operation can be transferred to the outside world via the lead frame, the heat sink, and the circuit board 66, further improving the heat dissipation efficiency of the chip package structure. An external heat sink 110 is mounted on the upper surface 101 of the main body 10 to further enhance the upward heat dissipation of the chip 60. The fixing member 111 may be, but is not limited to, a bolt. Fixing holes are provided on the edge of the circuit board 66, i.e., outside the projections of the chip 60 and the lead frame on the surface of the circuit board 66. The fixing member 111 is inserted into the fixing hole to connect the external heat sink 110 to the circuit board 66. The external heat sink 110 is connected to the circuit board 66 via the fixing member 111 located at the end of the external heat sink 110 (i.e., the fixing member 111 is located on the periphery of the heat dissipation cover). Since the provision of the external heat sink 110 causes the force on the chip 60 to gradually decrease from the edge to the center in a circular pattern similar to an isotherm, this specific embodiment reduces the force on the edge of the chip 60 by providing the support column 12. The support column 12, the support housing, and the lead frame together form a cage-like structure to protect the chip 60 in the center.

[0142] Figure 12 FIG. 1 is another cross-sectional schematic diagram of a chip packaging structure in a specific embodiment of the present invention. In other embodiments, as Figure 3 、 Figure 4 、 Figure 5 and Figure 12 As shown, the supporting shell is a solid shell.

[0143] In some embodiments, the heat dissipation cover further comprises:

[0144] A plurality of heat dissipation fins 40 are located on the upper surface 101 of the main body 10 .

[0145] For example, if Figure 3 、 Figure 4 、 Figure 5 and Figure 12As shown, for small-sized, low-power frame-type package products, even without an external heat sink or other external heat dissipation structure, the heat dissipation of the heat dissipation cover can ensure the normal operation of the chip. Therefore, in order to reduce heat dissipation costs and simplify the structure and manufacturing process of the heat dissipation cover, the support shell in the heat dissipation cover can be set as a solid shell, relying on the support shell itself to conduct heat, that is, the heat generated by the chip and the package can be transmitted to the outside through the solid support shell. For small-sized, low-power frame-type package products, air cooling can also be achieved through the heat dissipation fins 40, thereby further enhancing the heat dissipation effect of the package product. By arranging multiple heat dissipation fins 40 on the upper surface 101 of the main body 10 in a differential manner, the package body not only increases the heat dissipation area of ​​the package body under forced air cooling, but also makes it easier to form turbulence between adjacent heat dissipation fins 40, continuously destroying the thermal boundary layer formed on the surface, which is more conducive to heat dissipation than the laminar flow mode.

[0146] In some embodiments, the lower surface of the main body 10 includes a middle portion and a relief portion 102 located on the outer periphery of the middle portion, and the boss 11 is provided on the middle portion.

[0147] In some embodiments, the cross section of the main body 10 is in the shape of an inverted cone, the avoidance portion 102 forms an inverted cone wall, and the cross section of the boss 11 is rectangular.

[0148] Specifically, the cross-section of the boss 11 is rectangular, making it easier to mount on the front surface of the chip. The cross-section of the body 10 is an inverted cone. On the one hand, it can provide more space for the bonding wires in the package structure, thereby further ensuring the isolation between the supporting housing and the bonding wires; on the other hand, the coolant circulation channel is shorter, and the heat dissipation efficiency is higher.

[0149] In some embodiments, as Figure 6 、 Figure 7 、 Figure 8 、 Figure 9 and Figure 10 As shown, the lead frame includes a base island 61 and pins 64 distributed around the periphery of the base island 61, and the chip 60 is mounted on the base island 61;

[0150] The chip packaging structure further includes a bonding wire 70 , one end of which is electrically connected to the front surface of the chip 60 and the other end is electrically connected to the pin 64 . The vertical distance between the avoidance portion 102 of the main body 10 and the bonding wire 70 is 10 μm to 30 μm.

[0151] Specifically, since the boss 11 is protruding from the lower surface of the main body 10, sufficient space can be left for the bonding wire 70 through the outer wall of the boss 11 and the groove on the avoidance portion 102 in the main body 10, thereby avoiding the problem that the bonding wire 70 contacts the main body 10 and causes abnormalities in the chip packaging structure (for example, the bonding wire and the main body 10 are short-circuited). The distance between the avoidance portion 102 in the main body 10 and the bonding wire 70 is 10 microns to 30 microns, which can not only leave sufficient space for the bonding wire 70 to avoid contact between the supporting shell and the bonding wire 70, but also avoid the chip packaging structure from being too large. In one example, the vertical distance between the avoidance portion 102 of the main body 10 and the bonding wire 70 is 20 microns to 25 microns.

[0152] Figure 13 is another structural diagram of the support shell in a specific embodiment of the present invention. Figure 14 1 is another cross-sectional schematic diagram of a chip packaging structure in a specific embodiment of the present invention. In some other embodiments, the solid supporting shell can first form an initial shell of a frustum structure, and then directly cut the initial shell of the frustum structure according to the curvature of the bonding wire 70 to form a groove 130 in the avoidance portion 102 of the initial shell, such as Figure 13 As shown, the remaining initial shell and the bonding wire 70 are kept at a distance of 10 microns to 30 microns. After forming the groove 130, the remaining initial shell constitutes the supporting shell and is attached to the chip 60, as shown. Figure 14 shown.

[0153] In some embodiments, the chip packaging structure further includes:

[0154] The insulating adhesive film 62 is disposed between the boss 11 and the chip 60 and is used to adhere the heat dissipation cover to the chip 11 .

[0155] For example, the insulating adhesive film 62 may be, but is not limited to, a TIM (Thermal Interface Material) film. By disposing the insulating adhesive film 62 between the bottom surface 111 of the boss 11 and the chip 60, not only can the insulating adhesive film 62 bond the heat dissipation cover to the chip 60, reducing the contact thermal resistance between the heat dissipation cover and the chip 60, but also, because the insulating adhesive film 62 has a relatively low Young's modulus, when the package is subjected to external impact, the insulating adhesive film 62 can also serve as a buffer layer between the heat dissipation cover and the chip 60, reducing or even preventing damage to the chip 60 caused by external impact. Furthermore, the insulating adhesive film 62, made of insulating material, can also serve as an isolation layer between the heat dissipation cover and the chip 60, thereby further protecting the heat dissipation area of ​​the chip 60.

[0156] In some embodiments, the chip packaging structure further includes another insulating adhesive film located between the base island 61 and the chip 60 to bond the chip 60 to the base island 61, thereby reducing the contact thermal resistance between the chip 60 and the base island 61 while isolating the back side of the chip 60 from the base island 61.

[0157] In some embodiments, the chip packaging structure further includes:

[0158] A circuit board 66 , wherein the lead frame is located above the circuit board 66 ;

[0159] The plastic encapsulation layer 69 is located above the circuit board 66 , and the plastic encapsulation layer 69 encapsulates the lead frame and the chip 60 .

[0160] Figure 8 Schematic diagram of a portion of the lead frame structure in a specific embodiment of the present invention. Figure 6 、 Figure 7 , and 8, Figure 9 and Figure 10 As shown, the lead frame further includes a base island extension portion 63, which is connected to the end of the base island 61 and extends out of the plastic packaging layer 69;

[0161] One end of the support column 12 is connected to the end of the main body 10 , and the other end is connected to the upper surface of the base island extension portion 63 .

[0162] In some embodiments, the plurality of support columns 12 are symmetrically distributed around the periphery of the boss 11 , and the plurality of base island extensions 63 connected to the plurality of support columns 12 in a one-to-one correspondence are symmetrically distributed around the periphery of the base island 61 .

[0163] For example, the plastic encapsulation layer 69 is positioned between the circuit board 66 and the heat dissipation cover, with a gap between the plastic encapsulation layer 69 and the circuit board 66. The plastic encapsulation layer 69 continuously encapsulates the chip 60, the base island 61, the pins 64, and the heat sink 67. The end of the pin 64 facing away from the base island 61, the base island extension 63, and the support pillars 12 are exposed outside the plastic encapsulation layer 69. The end of the pin 64 facing away from the base island 61 is electrically connected to the top surface of the circuit board 66. Because the boss 11 of the heat dissipation cover is attached to the front surface of the chip 60, the plastic encapsulation layer 69 is distributed around the periphery of the boss 11. Multiple support pillars 12 are connected in a one-to-one correspondence with the multiple base island extensions 63 extending from the plastic encapsulation layer 69 in a direction parallel to the top surface 101 of the main body 10. This allows the heat dissipation cover to form a clamping force with the base island 61, further suppressing warping of the package. In addition, the heat dissipation cover and the lead frame are connected by a plurality of support columns 12 to form a cage structure. The chip 60 is located inside the cage structure, thereby further reducing the impact of the external environment on the chip 60.

[0164] In some embodiments, the support shell is made of metal.

[0165] Specifically, the support housing is made of metal, not only because it has excellent thermal conductivity, allowing it to more quickly transfer heat generated by the chip to the outside world, but also because it exhibits superior performance in parameters such as thermal expansion coefficient and Young's modulus, significantly reducing package warpage. In one example, the support housing is made of copper.

[0166] This specific embodiment also provides a method for forming a chip packaging structure. Figure 15 This is a flow chart of the method for forming a chip packaging structure in a specific embodiment of the present invention. The schematic diagram of the chip packaging structure formed in this specific embodiment can be found in Figures 1-14 .like Figures 1-15 As shown, the method for forming the chip packaging structure includes the following steps:

[0167] Step S131, forming a heat dissipation cover, the heat dissipation cover comprising a support housing and support columns 12, the support housing comprising a main body 10 and a boss 11 protruding from the lower surface of the main body 10, the main body 10 comprising an upper surface 101 and a lower surface relatively distributed, the boss 11 comprising a top surface facing the main body 10 and a bottom surface 111 opposite to the top surface, the area of ​​the upper surface 101 of the main body 10 being larger than the area of ​​the bottom surface 111 of the boss 11, the support columns 12 being connected to ends of the main body 10 and extending in a direction perpendicular to the upper surface 101 of the main body 10;

[0168] Step S132 , mounting a chip 60 onto a lead frame, wherein the chip 60 includes a front side and a back side that are relatively distributed, and the back side of the chip 60 faces the lead frame;

[0169] In step S133 , the heat dissipation cover is mounted on the front surface of the chip 60 along the bottom surface 111 of the boss 11 toward the front surface of the chip 60 , and the support pillars 12 are connected to the lead frame.

[0170] In some embodiments, the specific steps of mounting the chip 60 onto the lead frame include:

[0171] forming the lead frame, wherein the lead frame includes a base island 61, pins 64 distributed around the periphery of the base island 61, and a base island extension portion 63 connected to an end of the base island 61;

[0172] Mounting the chip 60 on the base island 61 along the direction from the back side of the chip 60 toward the base island 61;

[0173] A bonding wire 70 is formed, one end of which is electrically connected to the front surface of the chip 60 and the other end of which is electrically connected to the lead 64 .

[0174] In some embodiments, the specific steps of connecting the support pillar 12 to the lead frame include:

[0175] Connect the support column 12 and the base island extension portion 63.

[0176] In some embodiments, after attaching the heat dissipation cover to the front surface of the chip 60 along the bottom surface 111 of the boss 11 toward the front surface of the chip 60 and connecting the support pillars 12 to the lead frame, the following steps are further included:

[0177] A plastic layer 69 is formed under the heat dissipation cover to plastically encapsulate the base island 61, the pins 64 and the chip 60, and one end of the pins 64 away from the base island 61, the base island extension 63 and the support column 12 are exposed to the outside of the plastic layer 69.

[0178] For example, after forming the lead frame including the base island 61, the pins 64, and the base island extension 63, the chip 60 is mounted on the surface of the base island 61 with the back of the chip 60 facing the base island 61. Next, a bonding wire 70 is formed above the lead frame and electrically connects the chip 60 and the pins 64. Next, the heat dissipation cover is mounted on the front surface of the chip 60 along the bottom surface 111 of the boss 11 toward the front surface of the chip 60, and the support pillars 12 are connected to the base island extension 63. After the heat dissipation cover is mounted on the chip 60, a molding process is performed to form a molding layer 69 below the heat dissipation cover to encapsulate the base island 61, the pins 64, and the chip 60. The end of the pin 64 away from the base island 61, the base island extension 63, and the support pillars 12 are exposed outside the molding layer 69.

[0179] The heat dissipation cover, chip packaging structure, and method for forming the same are provided in this embodiment. A support housing and support columns are provided within the heat dissipation cover. The support housing includes a main body and a boss protruding from the lower surface of the main body. The main body includes an upper surface and a lower surface disposed opposite each other. The boss includes a top surface facing the main body and a bottom surface opposite the top surface. The area of ​​the upper surface of the main body is greater than the area of ​​the bottom surface of the boss. The bottom surface of the boss is used to cover the chip, thereby extending the heat source surface from the front of the chip to the entire surface of the package. This significantly increases the heat dissipation area of ​​the chip packaging structure and improves the heat dissipation effect of the chip within the chip packaging structure. Furthermore, because the boss protrudes from the lower surface of the main body, sufficient space is left for bonding wires between the outer wall of the boss and the lower surface of the main body, avoiding chip packaging structure abnormalities (e.g., short circuits between the heat dissipation cover and the bonding wires) caused by contact between the heat dissipation cover and the bonding wires, thereby ensuring the stability of the chip packaging structure performance. The bosses also expand the heat dissipation surface, quickly transferring heat generated by the chip to the package surface. Furthermore, the support shell is made of metal, which has better Young's modulus and coefficient of thermal expansion (CTE), thereby further improving the warping problem of the chip package structure.

[0180] At the same time, by providing support columns at the ends of the support housing for connection to the lead frame, a clamping force is generated through the connection between the support columns and the lead frame, reducing or even suppressing warping of the lead frame and the entire package. Furthermore, the provision of the support columns can provide more support for the heat dissipation cover when attaching an external heat sink, ensuring that the chip is not affected by the external heat sink during installation.

[0181] It should be noted that the terms "including," "having," and their variations, as used in this document, are intended to cover non-exclusive inclusions. Terms such as "first," "second," and the like are used to distinguish similar items and are not necessarily used to describe a specific order or precedence, unless the context clearly indicates otherwise. Such usage should be understood to be interchangeable where appropriate. The term "one or more" may be used to describe a feature, structure, or characteristic in the singular, or in the plural, depending at least in part on the context, to describe a feature, structure, or combination of features. The term "based on" should be understood as not necessarily intended to express an exclusive set of factors, but may alternatively, also depending at least in part on the context, allow for the presence of other factors that are not necessarily explicitly described. Furthermore, the embodiments of the present invention and the features therein may be combined with one another, unless there is a conflict. Furthermore, descriptions of well-known components and technologies have been omitted from the above description to avoid unnecessary confusion regarding the concepts of the present invention. In each of the above embodiments, each embodiment focuses on its differences from the other embodiments, and reference may be made to the same or similar parts between the embodiments.

[0182] The above description is only a preferred embodiment of the present invention. It should be pointed out that ordinary technicians in this technical field can make several improvements and modifications without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A heat dissipation cover, characterized in that: include: A support housing, comprising a main body and a boss protruding from the lower surface of the main body, wherein the main body comprises an upper surface and a lower surface that are relatively distributed, and the boss comprises a top surface facing the main body and a bottom surface opposite to the top surface, wherein the area of ​​the upper surface of the main body is larger than the area of ​​the bottom surface of the boss, and the bottom surface of the boss is used for mounting on a chip; A support column is connected to an end of the main body and extends in a direction perpendicular to the upper surface of the main body, and is used to be connected to a lead frame.

2. The heat dissipation cover according to claim 1, characterized in that: Also includes: A vacuum containing chamber, located inside the supporting shell; a capillary structure layer, located on the inner wall of the vacuum containing chamber; The cooling liquid is located in the vacuum containing chamber.

3. The heat dissipation cover according to claim 2, characterized in that: The cooling liquid occupies 30% to 40% of the volume of the vacuum containing chamber.

4. The heat dissipation cover according to claim 3, characterized in that: The vacuum housing chamber is only located in the boss; or The vacuum containing chambers are continuously distributed in the boss and the main body.

5. The heat dissipation cover according to claim 1, wherein: The supporting shell is a solid shell.

6. The heat dissipation cover according to claim 5, characterized in that: Also includes: A plurality of heat dissipation fins are located on the upper surface of the main body.

7. The heat dissipation cover according to claim 6, characterized in that: A plurality of heat dissipation fins are arranged at intervals on the upper surface of the main body in a staggered manner.

8. The heat dissipation cover according to claim 1, wherein: The lower surface of the main body includes a middle portion and an escape portion located on an outer peripheral side of the middle portion, and the boss is provided on the middle portion.

9. The heat dissipation cover according to claim 8, characterized in that: The cross section of the main body is an inverted cone, the avoidance portion forms an inverted cone wall, and the cross section of the boss is a rectangle.

10. The heat dissipation cover according to claim 8, characterized in that: A groove is formed on the avoidance portion.

11. The heat dissipation cover according to claim 1, wherein: There are multiple support columns, and the multiple support columns are symmetrically distributed around the outer periphery of the boss.

12. The heat dissipation cover according to claim 11, characterized in that: The upper surface of the main body is rectangular, and the four support columns are distributed at the four corners of the rectangular main body in a one-to-one correspondence.

13. The heat dissipation cover according to claim 1, wherein: The support shell is made of metal.

14. A chip packaging structure, characterized in that: include: Chip, including the front and back sides that are relatively distributed; a lead frame, the chip being mounted on the lead frame with the back surface of the chip facing the lead frame; A heat dissipation cover includes a support shell and a support column, wherein the support shell includes a main body and a boss protruding from the lower surface of the main body, the main body includes an upper surface and a lower surface that are relatively distributed, the boss includes a top surface facing the main body and a bottom surface opposite to the top surface, and the area of ​​the upper surface of the main body is larger than the area of ​​the bottom surface of the boss, the bottom surface of the boss is mounted on the front side of the chip, the support column extends in a direction perpendicular to the upper surface of the main body, one end of the support column is connected to the end of the main body, and the other end is connected to the lead frame.

15. The chip packaging structure according to claim 14, wherein: The front surface of the chip includes a heat dissipation area and a functional area arranged around the periphery of the heat dissipation area, wherein a plurality of metal contacts are arranged in the functional area; The bottom surface of the boss is mounted on the heat dissipation area, and the area of ​​the bottom surface of the boss is smaller than the area of ​​the heat dissipation area.

16. The chip packaging structure according to claim 14, wherein: The heat dissipation cover further comprises: a vacuum accommodating chamber located inside the supporting shell; a capillary structure layer, located on the inner wall of the vacuum containing chamber; The cooling liquid is located in the vacuum containing chamber.

17. The chip packaging structure according to claim 16, wherein: The cooling liquid occupies 30% to 40% of the volume of the vacuum containing chamber.

18. The chip packaging structure according to claim 17, wherein: The vacuum housing chamber is only located in the boss; or The vacuum containing chambers are continuously distributed in the boss and the main body.

19. The chip packaging structure according to claim 17, wherein: Also includes: A circuit board, wherein the lead frame is located above the circuit board; An external radiator is mounted on the upper surface of the main body, and a fixing piece is provided at the end of the external radiator, one end of the fixing piece is connected to the external radiator, and the other end is connected to the circuit board.

20. The chip packaging structure according to claim 14, wherein: The supporting shell is a solid shell.

21. The chip packaging structure according to claim 20, wherein: The heat dissipation cover further includes: a plurality of heat dissipation ribs located on the upper surface of the main body.

22. The chip packaging structure according to claim 14, wherein: The lower surface of the main body includes a middle portion and an escape portion located on an outer peripheral side of the middle portion, and the boss is provided on the middle portion.

23. The chip packaging structure according to claim 22, wherein: The cross section of the main body is an inverted cone, the avoidance portion forms an inverted cone wall, and the cross section of the boss is a rectangle.

24. The chip packaging structure according to claim 22, wherein: The lead frame includes a base island and pins distributed around the periphery of the base island, and the chip is mounted on the base island; The chip packaging structure also includes a bonding wire, one end of which is electrically connected to the front surface of the chip and the other end is electrically connected to the pin. The vertical distance between the avoidance portion of the main body and the bonding wire is 10 microns to 30 microns.

25. The chip packaging structure according to claim 24, wherein: A groove is formed on the avoidance portion at a position corresponding to the bonding wire.

26. The chip packaging structure according to claim 24, wherein: Also includes: An insulating adhesive film is provided between the boss and the chip and is used for adhering the heat dissipation cover to the chip.

27. The chip packaging structure according to claim 24, wherein: Also includes: A circuit board, wherein the lead frame is located above the circuit board; A plastic encapsulation layer is located above the circuit board, and the plastic encapsulation layer encapsulates the lead frame and the chip. One end of the pin away from the base island is exposed to the outside of the plastic encapsulation layer, and the other end of the pin away from the base island is electrically connected to the upper surface of the circuit board.

28. The chip packaging structure according to claim 27, characterized in that: The lead frame further includes a base island extension portion, which is connected to the end of the base island and extends out of the plastic packaging layer; one end of the support column is connected to the end of the main body, and the other end is connected to the base island extension portion.

29. The chip packaging structure according to claim 28, wherein: The plurality of support columns are symmetrically distributed around the periphery of the boss, and the plurality of base island extensions connected to the plurality of support columns in a one-to-one correspondence are symmetrically distributed around the periphery of the base island.

30. The chip packaging structure according to claim 14, wherein: The support shell is made of metal.

31. A method for forming a chip packaging structure, characterized in that: The steps include: A heat dissipation cover is formed, the heat dissipation cover comprising a support shell and a support column, the support shell comprising a main body and a boss protruding from a lower surface of the main body, the main body comprising an upper surface and a lower surface that are oppositely distributed, the boss comprising a top surface facing the main body and a bottom surface opposite to the top surface, wherein the area of ​​the upper surface of the main body is larger than the area of ​​the bottom surface of the boss, and the support column is connected to an end of the main body and extends in a direction perpendicular to the upper surface of the main body; Mounting a chip on a lead frame, wherein the chip includes a front side and a back side that are relatively distributed, and the back side of the chip faces the lead frame; The heat dissipation cover is mounted on the front surface of the chip along the bottom surface of the boss toward the front surface of the chip, and the support column and the lead frame are connected.

32. The method for forming a chip packaging structure according to claim 31, wherein: The specific steps for mounting the chip on the lead frame include: forming the lead frame, wherein the lead frame includes a base island, pins distributed around the periphery of the base island, and a base island extension connected to an end of the base island; Mounting the chip on the base island along the back side of the chip toward the base island; A bonding wire is formed with one end electrically connected to the front surface of the chip and the other end electrically connected to the pin.

33. The method for forming a chip packaging structure according to claim 32, wherein: The specific steps of connecting the support column and the lead frame include: The supporting column is connected to the base island extension portion.

34. The method for forming a chip packaging structure according to claim 33, wherein: After attaching the heat dissipation cover to the front surface of the chip along the bottom surface of the boss toward the front surface of the chip and connecting the support pillars and the lead frame, the following steps are further included: A plastic packaging layer for packaging the base island, the pins and the chip is formed below the heat dissipation cover, and one end of the pin away from the base island, the base island extension and the support column are exposed outside the plastic packaging layer.

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